All about large intestine

1. LARGE INTESTINE
Dr Rajeev Kumar Pandit
FCPS 1st Yr Surgery Resident
Manmohan Memorial Medical College
Swoyambhu, Nepal

2. Embryology
• The embryonic gastrointestinal tract begins developing during the fourth
week of gestation.
• The primitive gut is derived from the endoderm and divided into three
segments:
• Foregut,
• Midgut
• Hindgut
• Both midgut and hindgut contribute to the colon, rectum, and anus.
• The midgut develops into the small intestine, ascending colon, and
proximal transverse colon, and receives blood supply from the superior
mesenteric artery

3. • The hindgut develops into the distal transverse colon, descending colon,
rectum, and proximal anus, all of which receive their blood supply from
the inferior mesenteric artery.
• The distal-most end of the hindgut, the cloaca, is divided by the urorectal
septum into the urogenital sinus and the rectum.
• The distal anal canal is derived from ectoderm and receives its blood
supply from the internal pudendal artery.
• The dentate line divides the endodermal hindgut from the ectodermal
distal anal canal.

4. Anatomy
• Extends from the ileocecal valve to the anus.
• Divided anatomically and functionally into the colon, rectum, and anal canal.
• The wall of the colon and rectum comprise five distinct layers:
• Mucosa,
• Submucosa,
• Inner circular muscle,
• Outer longitudinal muscle, and
• Serosa.
• In the colon, the outer longitudinal muscle is separated into three teniae coli,
which converge proximally at the appendix and distally at the rectum, where
the outer longitudinal muscle layer is circumferential.

5. • In the distal rectum, the inner smooth muscle layer coalesces to form
the internal anal sphincter.
• The intraperitoneal colon and proximal one-third of the rectum are
covered by serosa; the mid and lower rectum lack serosa.

6. •Colon Landmarks.
• The colon begins at the junction of the terminal ileum and cecum and
extends the rectum.
• The rectosigmoid junction is found at approximately the level of the
sacral promontory and is arbitrarily described as the point at which the
three teniae coli coalesce to form the outer longitudinal smooth
muscle layer of the rectum.
• The cecum is the widest diameter portion of the colon (normally 7.5–
8.5 cm) and has the thinnest muscular wall.
• As a result, the cecum is most vulnerable to perforation and least
vulnerable to obstruction.
• The ascending colon is usually fixed to the retroperitoneum.
• The hepatic flexure marks the transition to the transverse colon.

7. • The intraperitoneal transverse colon is relatively mobile, but is tethered
by the gastrocolic ligament and colonic mesentery.
• The greater omentum is attached to the anterior/superior edge of the
transverse colon.
• These attachments explain the characteristic triangular appearance of
the transverse colon observed during colonoscopy.
• The splenic flexure marks the transition from the transverse colon to the
descending colon.
• The attachments between the splenic flexure and the spleen (the
lienocolic ligament) can be short and dense, making mobilization of this
flexure during colectomy challenging.
• The descending colon is relatively fixed to the retroperitoneum.

8. • The sigmoid colon is the narrowest part of the large intestine and is
extremely mobile.
• Although the sigmoid colon is usually located in the left lower quadrant,
redundancy and mobility can result in a portion of the sigmoid colon
residing in the right lower quadrant.
• This mobility explains why volvulus is most common in the sigmoid colon
and why diseases affecting the sigmoid colon, such as diverticulitis, may
occasionally present as right-sided abdominal pain.
• The narrow caliber of the sigmoid colon makes this segment of the large
intestine the most vulnerable to obstruction.

9. • Colon Vascular Supply.
• Superior mesenteric artery branches into
• Ileocolic artery (absent in up to 20% of people) ---the terminal ileum and proximal
ascending colon
• Right colic artery ---- the ascending colon
• Middle colic artery ----- the transverse colon.
• Inferior mesenteric artery branches into the
• Left colic artery ------ the descending colon;
• Several sigmoidal branches ------- the sigmoid colon; and
• Superior rectal artery ------- the proximal rectum.
• The terminal branches of each artery form anastomoses with the terminal
branches of the adjacent artery and communicate via the marginal artery of
Drummond. This arcade is complete in only 15% to 20% of people.

11. • Except for the inferior mesenteric vein, the veins of the colon parallel
their corresponding arteries and bear the same terminology
• The inferior mesenteric vein ascends in the retroperitoneal plane over
the psoas muscle and continues posterior to the pancreas to join the
splenic vein.
• During a colectomy, this vein is often mobilized independently and
ligated at the inferior edge of the pancreas

13. • Colon Lymphatic Drainage.
• The lymphatic drainage of the colon originates in a network of lymphatics in the
muscularis mucosa.
• Lymphatic vessels and lymph nodes follow the regional arteries.
• Lymph nodes are found
• On the bowel wall (epicolic),
• Along the inner margin of the bowel adjacent to the arterial arcades (paracolic),
• Around the named mesenteric vessels (intermediate), and
• At the origin of the superior and inferior mesenteric arteries (main).
• The sentinel lymph nodes are the first one to four lymph nodes to drain a specific
segment of the colon and are thought to be the first site of metastasis in colon
cancer.
• The utility of sentinel lymph node dissection and analysis in colon cancer remains
controversial.

14. • Colon Nerve Supply.
• The colon is innervated by both sympathetic (inhibitory) and parasympathetic
(stimulatory) nerves, which parallel the course of the arteries.
• Sympathetic nerves arise from T6-T12 and L1-L3.
• Parasympathetic innervation to the right and transverse colon is from the vagus
nerve;
• Parasympathetic nerves to the left colon arise from sacral nerves S2-S4 to form
the nervi erigentes.

15. • Anorectal Landmarks.
• The rectum is approximately 12 to 15 cm in length.
• Three distinct submucosal folds, the valves of Houston, extend into the rectal
lumen.
• Posteriorly, the presacral fascia separates the rectum from the presacral venous
plexus and the pelvic nerves.
• At S4, the recto-sacral fascia (Waldeyer’s fascia) extends forward and downward
and attaches to the fascia propria at the anorectal junction.
• Anteriorly, Denonvilliers’ fascia separates the rectum from the prostate and
seminal vesicles in men and from the vagina in women.
• The lateral ligaments support the lower rectum.

16. • Anal canal
• Anatomical anal canal extends from the dentate or pectinate line to the anal
verge.
• The dentate or pectinate line marks the transition point between columnar rectal
mucosa and squamous anoderm.
• The anal transition zone includes mucosa proximal to the dentate line that shares
histologic characteristics of columnar, cuboidal, and squamous epithelium.
• Although the anal transition zone was long thought to extend only 1 to 2 cm
proximal to the dentate line, it is known that the proximal extent of this zone is
highly variable and can be as far as 15 cm proximal to the dentate line.
• The dentate line is surrounded by longitudinal mucosal folds, known as the
columns of Morgagni, into which the anal crypts empty. These crypts are the
source of cryptoglandular abscesses.
• In contrast to the anatomic anal canal, the surgical anal canal begins at the
anorectal junction and terminates at the anal verge.
• The surgical anal canal measures 2 to 4 cm in length and is generally longer in
men than in women.

18. • In the distal rectum, the inner smooth muscle is thickened and
comprises the internal anal sphincter that is surrounded by the
subcutaneous, superficial, and deep external sphincter.
• The deep external anal sphincter is an extension of the puborectalis
muscle.
• The puborectalis, iliococcygeus, and pubococcygeus muscles form the
levator ani muscle of the pelvic floor.

20. • Anorectal Vascular Supply.
• Superior rectal artery arises from the terminal branch of the inferior mesenteric artery and
supplies the upper rectum.
• Middle rectal artery arises from the internal iliac; the presence and size of these arteries are highly
variable.
• Inferior rectal artery arises from the internal pudendal artery, which is a branch of the internal iliac
artery.
• A rich network of collaterals connects the terminal arterioles of each of these arteries,
thus making the rectum relatively resistant to ischemia.
• The venous drainage of the rectum parallels the arterial supply.
• The superior rectal vein drains into the portal system via the inferior mesenteric vein.
• The middle rectal vein drains into the internal iliac vein.
• The inferior rectal vein drains into the internal pudendal vein, and subsequently into the internal
iliac vein.
• A submucosal plexus deep to the columns of Morgagni forms the hemorrhoidal plexus
and drains into all three veins.

22. • Anorectal Lymphatic Drainage.
• Lymphatic drainage of the rectum parallels the vascular supply.
• Lymphatic channels in the upper and middle rectum drain superiorly into the
inferior mesenteric lymph nodes.
• Lymphatic channels in the lower rectum drain both superiorly into the inferior
mesenteric lymph nodes and laterally into the internal iliac lymph nodes.
• The anal canal has a more complex pattern of lymphatic drainage.
• Proximal to the dentate line, lymph drains into both the inferior mesenteric
lymph nodes and the internal iliac lymph nodes.
• Distal to the dentate line, lymph primarily drains into the inguinal lymph nodes,
but can also drain into the inferior mesenteric lymph nodes and internal iliac
lymph nodes.

23. • Anorectal Nerve Supply.
• Both sympathetic and parasympathetic nerves innervate the anorectum.
• Sympathetic nerve fibers are derived from L1-L3 and join the preaortic plexus. The preaortic
nerve fibers then extend below the aorta to form the hypogastric plexus, which subsequently
joins the parasympathetic fibers to form the pelvic plexus.
• Parasympathetic nerve fibers are known as the nervi erigentes and originate from S2-S4.
• These fibers join the sympathetic fibers to form the pelvic plexus.
• Sympathetic and parasympathetic fibers then supply the anorectum and adjacent urogenital
organs.
• The internal anal sphincter is innervated by sympathetic and parasympathetic nerve fibers;
both types of fibers inhibit sphincter contraction.
• The external anal sphincter and puborectalis muscles are innervated by the inferior rectal
branch of the internal pudendal nerve.
• The levator ani receives innervation from both the internal pudendal nerve and direct
branches of S3 to S5.
• Sensory innervation to the anal canal is provided by the inferior rectal branch of the
pudendal nerve. While the rectum is relatively insensate, the anal canal below the dentate
line is sensate.

26. Physiology
• Water, Sodium, Potassium, Chloride, Bicarbonate, and Ammonia
• Colon is a major site for water absorption and electrolyte exchange
• Approximately 90% of the water contained in ileal fluid is absorbed in the
colon
• Sodium is absorbed actively via sodium potassium (Na+/K+) ATPase.
• Water accompanies the transported sodium and is absorbed passively along
an osmotic gradient.
• Potassium is actively secreted into the colonic lumen and absorbed by passive
diffusion.
• Chloride is absorbed actively via a chloride bicarbonate exchange.
• Bacterial degradation of protein and urea produces ammonia. Ammonia is
subsequently absorbed and transported to the liver

27. • Short-Chain Fatty Acids
• Short-chain fatty acids (acetate, butyrate, and propionate) are produced by
bacterial fermentation of dietary carbohydrates.
• Are an important source of energy for the colonic mucosa, and metabolism by
colonocytes provides energy for processes such as active transport of sodium.
• Lack of a dietary source for production of short-chain fatty acids, or diversion
of the fecal stream by an ileostomy or colostomy, may result in mucosal
atrophy and inflammation, the latter termed “diversion colitis.”

28. • Colonic Microflora
• Approximately 30% of fecal dry weight is composed of bacteria (10^11–1012
bacteria/g of feces).
• Anaerobes are the predominant class of microorganism, and Bacteroides species
are the most common (1011–1012 organisms/mL).
• Escherichia coli are the most numerous aerobes (108–1010 organisms/mL).
• Endogenous microflora are crucial for the breakdown of carbohydrates and proteins
in the colon and participate in the metabolism of bilirubin, bile acids, estrogen, and
cholesterol.
• Colonic bacteria also are necessary for production of vitamin K.
• Endogenous bacteria also are thought to suppress the emergence of pathogenic
microorganisms, such as Clostridium difficile, a phenomenon termed “colonization
resistance.” However, the high bacterial load of the large intestine may contribute
to sepsis in critically ill patients and may contribute to intra-abdominal sepsis,
abscess, and wound infection following colectomy.

29. • Intestinal Gas
• Arises from swallowed air, diffusion from the blood, and intraluminal
production.
• Nitrogen, oxygen, carbon dioxide, hydrogen, and methane are the major
components of intestinal gas.
• Nitrogen and oxygen are largely derived from swallowed air.
• Carbon dioxide is produced by the reaction of bicarbonate and hydrogen ions
and by the digestion of triglycerides to fatty acids.
• Hydrogen and methane are produced by colonic bacteria.
• The production of methane is highly variable.
• The gastrointestinal tract usually contains between 100 and 200 mL of gas, and
400 to 1200 mL/d are released as flatus, depending on the type of food
ingested.

30. • Motility.
• Unlike the small intestine, the large intestine does not demonstrate cyclic motor
activity characteristic of the migratory motor complex.
• Instead, the colon displays intermittent contractions of either low or high amplitude.
• Low-amplitude, short-duration contractions occur in bursts and appear to move the
colonic contents both antegrade and retrograde.
• It is thought that these bursts of motor activity delay colonic transit and thus
increase the time available for absorption of water and exchange of electrolytes.
• High-amplitude contractions occur in a more coordinated fashion and create “mass
movements.” Bursts of “rectal motor complexes” also have been described.
• In general, cholinergic activation increases colonic motility.

31. • Defecation.
• A complex, coordinated mechanism involving colonic mass movement, increased
intra-abdominal and rectal pressure, and relaxation of the pelvic floor.
• Distention of the rectum causes a reflex relaxation of the internal anal sphincter (the
recto-anal inhibitory reflex) that allows the contents to make contact with the anal
canal.
• This “sampling reflex” allows the sensory epithelium to distinguish solid stool from
liquid stool and gas.
• If defecation does not occur, the rectum relaxes and the urge to defecate passes
(accommodation response).
• Defecation proceeds by coordination of increasing intra-abdominal pressure via the
Valsalva maneuver, increased rectal contraction, relaxation of the puborectalis
muscle, and opening of the anal canal.

32. •Continence
• The maintenance of fecal continence is at least as complex as the mechanism of defecation.
• Continence requires adequate rectal wall compliance to accommodate the fecal bolus,
appropriate neurogenic control of the pelvic floor and sphincter mechanism, and functional
internal and external sphincter muscles.
• At rest, the puborectalis muscle creates a “sling” around the distal rectum, forming a
relatively acute angle that distributes intra-abdominal forces onto the pelvic floor.
• With defecation, this angle straightens, allowing downward force to be applied along the
axis of the rectum and anal canal.
• The internal and external sphincters are tonically active at rest.
• The internal sphincter is responsible for most of the resting, involuntary sphincter tone
(resting pressure).
• The external sphincter is responsible for most of the voluntary sphincter tone (squeeze
pressure).
• Branches of the pudendal nerve innervate both the internal and external sphincter.
• Finally, the hemorrhoidal cushions may contribute to continence by mechanically blocking
the anal canal.
• Thus, impaired continence may result from poor rectal compliance, injury to the internal
and/or external sphincter or puborectalis, or nerve damage or neuropathy.

33. • Ileocolic Resection.
• limited resection of
• the terminal ileum,
• cecum, and
• appendix.
• It is used to remove disease involving these segments of the intestine (e.g., ileocecal
Crohn’s disease) and benign lesions or incurable cancers arising in the terminal
ileum, cecum, and, occasionally, the appendix.
• The ileocolic vessels are ligated and divided.
• Right Colectomy.
• To remove lesions or disease in the right colon and is oncologically the most
appropriate operation for curative intent resection of proximal colon carcinoma.
• The ileocolic vessels, right colic vessels, and right branches of the middle colic vessels
are ligated and divided.
• Approximately 10 cm of terminal ileum are usually included in the resection. A
primary ileal-transverse colon anastomosis is almost always possible.

34. • Extended Right Colectomy.
• Resection of lesions located at the hepatic flexure or proximal transverse colon.
• A standard right colectomy is extended to include ligation of the middle colic vessels at
their base.
• The right colon and proximal transverse colon are resected,
• Primary anastomosis is created between the distal ileum and distal transverse colon.
• Transverse Colectomy.
• Lesions in the mid and distal transverse colon may be resected by ligating the middle colic
vessels and resecting the transverse colon, followed by a colocolonic anastomosis.
• However, an extended right colectomy with an anastomosis between the terminal ileum
and descending colon may be a safer anastomosis with an equivalent functional result.
• Left Colectomy.
• For lesions or disease states confined to the distal transverse colon, splenic flexure, or
descending colon, a left colectomy is performed.
• The left branches of the middle colic vessels, the left colic vessels, and the first branches
of the sigmoid vessels are ligated.
• A colocolonic anastomosis can usually be performed.

35. • Extended Left Colectomy.
• An extended left colectomy is an option for removing lesions in the distal
transverse colon.
• In this operation, the left colectomy is extended proximally to include the right
branches of the middle colic vessels.
• Sigmoid Colectomy.
• Lesions in the sigmoid colon require ligation and division of the sigmoid branches
of the inferior mesenteric artery.
• In general, the entire sigmoid colon should be resected to the level of the
peritoneal reflection and an anastomosis created between the descending colon
and upper rectum.
• Full mobilization of the splenic flexure is often required to create a tension-free
anastomosis

36. • Total and Subtotal Colectomy.
• Indication
• Fulminant colitis,
• Attenuated FAP, or
• Synchronous colon carcinomas.
• In this procedure, the ileocolic vessels, right colic vessels, middle colic vessels, and
left colic vessels are ligated and divided.
• The superior rectal vessels are preserved.
• Subtotal colectomy with ileosigmoid anastomosis -- distal sigmoid vessels are left
intact, and an anastomosis is created between the ileum and distal sigmoid colon.
• Total abdominal colectomy with ileorectal anastomosis---- the sigmoidal vessels are
ligated and divided, and the ileum is anastomosed to the upper rectum.
• If an anastomosis is contraindicated, an end ileostomy is created, and the remaining
sigmoid or rectum is managed either as a mucus fistula or a Hartmann’s pouch.

37. • Total Proctocolectomy
• In this procedure, the entire colon, rectum, and anus are removed and the
ileum is brought to the skin as a Brooke ileostomy.

39. • Restorative Proctocolectomy (Ileal Pouch–Anal Anastomosis).
• The entire colon and rectum are resected, but the anal sphincter muscles and
a variable portion of the distal anal canal are preserved.
• Bowel continuity is restored by anastomosis of an ileal reservoir to the anal
canal.
• The original technique included a transanal mucosectomy and hand-sewn
ileoanal anastomosis.
• Proponents of this technique argue that mucosectomy guarantees removal of
all of the diseased mucosa, including the anal transition zone, and therefore
decreases the risk of ongoing disease, dysplasia, and carcinoma.
• Increased risk of incontinence after mucosectomy and argue that even
meticulous technique invariably leaves behind mucosal “islands” that are
subsequently hidden under the anastomosis.
• Moreover, the “double-staple” technique using the circular stapling devices is
considerably simpler than mucosectomy and a hand-sewn anastomosis and
may be associated with a better functional outcome

40. • Regardless of the anastomotic technique, many surgeons recommend that
patients undergo annual surveillance of the anastomosis and/or anal transition
zone by digital rectal exam and anoscopy or proctoscopy.
• The neorectum is made by anastomosis of the terminal ileum aligned in a “J,” “S,”
or “W” configuration.
• Because functional outcomes are similar and because the J-pouch is the simplest
to construct, it has become the most used configuration.
• With increasing experience in laparoscopic and robotic colectomy, some centers
have begun performing total proctocolectomy with ileal pouch–anal
reconstruction using minimally invasive surgical techniques.
• Most surgeons perform a proximal ileostomy to divert succus from the newly
created pouch in an attempt to minimize the consequences of leak and sepsis,
especially in patients who are malnourished or immunosuppressed
• The ileostomy is then closed 6 to 12 weeks later, after a contrast study confirms
the integrity of the pouch. In low-risk patients, however, there are reports of
successful creation of an ileoanal pouch without a diverting stoma.

41. Anterior Resection
• Anterior resection is the general term used to describe resection of the
rectum from an abdominal approach to the pelvis with no need for a
perineal, sacral, or other incision.
• Three types of anterior resection have been described
1. High Anterior Resection.
• Used to describe resection of the distal sigmoid colon and upper rectum and is the
appropriate operation for benign lesions and disease at the rectosigmoid junction
such as diverticulitis.
• The upper rectum is mobilized, but the pelvic peritoneum is not divided and the
rectum is not mobilized fully from the concavity of the sacrum.
• The inferior mesenteric artery is ligated at its base, and the inferior mesenteric vein,
which follows a different course than the artery, is ligated separately.
• A primary anastomosis (usually end-to-end) between the colon and rectal stump
with a short cuff of peritoneum surrounding its anterior two thirds generally can be
performed.

42. 2. Low Anterior Resection
• Used to remove lesions in the upper and mid rectum.
• The rectosigmoid is mobilized, the pelvic peritoneum is opened, and the inferior
mesenteric artery is ligated and divided either at its origin from the aorta or just distal
to the takeoff of the left colic artery.
• The rectum is mobilized from the sacrum by sharp dissection under direct view within
the endopelvic fascial plane.
• The dissection may be performed distally to the anorectal ring, extending posteriorly
through the rectosacral fascia to the coccyx and anteriorly through Denonvilliers’
fascia to the vagina in women or the seminal vesicles and prostate in men.
• The rectum and accompanying mesorectum are divided at the appropriate level,
depending on the nature of the lesion.
• A low rectal anastomosis usually requires mobilization of the splenic flexure and
ligation and division of the inferior mesenteric vein just inferior to the pancreas.
• Circular stapling devices have greatly facilitated the conduct and improved the safety
of the colon to extraperitoneal rectal anastomosis.

43. 3. Extended Low Anterior Resection.
• An extended low anterior resection is necessary to remove lesions located in the
distal rectum, but several centimeters above the sphincter.
• The rectum is fully mobilized to the level of the Levator ani muscle just as for a
low anterior resection, but the anterior dissection is extended along the
rectovaginal septum in women and distal to the seminal vesicles and prostate in
men.
• After resection at this level, a coloanal anastomosis can be created using one of a
variety of techniques.
• An end-to-end stapled or hand-sewn anastomosis has traditionally been the
procedure of choice.
• However, the functional consequences of a “straight” anastomosis have led to
consideration for creation of a colon J-pouch or transverse coloplasty to increase
the capacity of the neo-rectal reservoir.

44. Hartmann’s Procedure and Mucus Fistula
• Refers to a colon or rectal resection without an anastomosis in which
a colostomy or ileostomy is created and the distal colon or rectum is
left as a blind pouch.
• The term is typically used when the left or sigmoid colon is resected
and the closed off rectum is left in the pelvis.
• If the distal colon is long enough to reach the abdominal wall, a
mucus fistula can be created by opening the defunction bowel and
suturing the open lumen to the skin.

45. Abdominoperineal Resection
• Removal of the entire rectum, anal canal, and anus with construction of a permanent
colostomy from the descending or sigmoid colon.
• The abdominal-pelvic portion of this operation proceeds in the same fashion as
described for an extended low anterior resection.
• The perineal dissection can be performed with the patient in lithotomy position (often
by a second surgeon) or in the prone position after closure of the abdomen and
creation of the colostomy.
• For cancer, the perineal dissection is designed to excise the anal canal with a wide
circumferential margin including a cylindrical cuff of the levator muscle.
• Primary wound closure is usually successful, but a large perineal defect, especially if
preoperative radiation has been used, may require a vascularized flap closure in some
patients.
• For benign disease, proctectomy may be performed using an intersphincteric
dissection between the internal and external sphincters. This approach minimizes the
perineal wound, making it easier to close because the levator muscle remains intact.

46. Anastomoses
• May be created between two segments of bowel in a multitude of ways.
• The geometry of the anastomosis may be
• end-to-end,
• end-to-side,
• side-to-end, or
• side-to-side.
• The anastomotic technique may be hand-sewn or stapled.
• The submucosal layer of the intestine provides the strength of the bowel wall and must be incorporated
in the anastomosis to assure healing.
• The choice of anastomosis depends on the operative anatomy and surgeon preference.
• Accurate approximation of two well-vascularized, healthy limbs of bowel without tension in a
normotensive, well nourished patient almost always results in a good outcome.
• Anastomoses at highest risk of leak or stricture are those that are in the distal rectal or anal canal,
involve irradiated or diseased intestine including perforation with peritoneal soilage, or are performed
in malnourished, immunosuppressed, or ill patients.

47. • Anastomotic Configuration
• End-to-End.
• Can be performed when two segments of bowel are roughly the same caliber.
• This technique is most often employed in rectal resections, but may be used for colo-colostomy
or small bowel anastomoses.
• End-to-Side.
• Useful when one limb of bowel is larger than the other.
• This most commonly occurs in the setting of chronic obstruction.
• Side-to-End.
• Used when the proximal bowel is of smaller caliber than the distal bowel.
• Ileorectal anastomoses commonly make use of this configuration.
• A side-to-end anastomosis may have a less tenuous blood supply than an end-to-end
anastomosis.
• Side-to-Side.
• Allows a large, well vascularized connection to be created on the antimesenteric side of two
segments of intestine.
• This technique is commonly used in ileocolic and small bowel anastomoses.

48. Anastomotic Technique
• Hand-Sutured Technique.
• May be
• single layer
• double layer.
• A double-layer anastomosis usually consists of a continuous inner layer and
an interrupted outer layer.
• Suture material may be either permanent or absorbable.
• After distal rectal or anal canal resection, a transanal, hand-sewn coloanal
anastomosis may be necessary to restore bowel continuity.
• This can be done in conjunction with an anal canal mucosectomy to allow the
anastomosis to be created at the dentate line.

49. • Stapled Techniques.
• Linear cutting/stapling devices are used to divide the bowel and to create
side-to-side anastomoses.
• The anastomosis may be reinforced with interrupted sutures if desired.
• Circular cutting/stapling devices can create end-to-end, end-to-side, or side-
to-end anastomoses.
• These instruments are particularly useful for creating low rectal or anal canal
anastomoses where the anatomy of the pelvis makes a hand-sewn
anastomosis technically difficult or impossible.

50. Ostomies
• A stoma may be temporary or permanent.
• It may be end-on or a loop.
• Ideally, a stoma should be placed in a location that the patient can easily see and manipulate, within
the rectus muscle, and below the belt line.
• Procedure
• For all stomas, a circular skin incision is created and the subcutaneous tissue dissected to the level of the
anterior rectus sheath.
• The anterior rectus sheath is incised in a cruciate fashion, the muscle fibers separated bluntly, and the
posterior sheath identified and incised.
• Care should be taken to avoid injuring and causing bleeding from the inferior epigastric artery and vein.
• The size of the defect depends on the size of the bowel used to create the stoma, but should be as small as
possible without compromising the intestinal blood supply (usually the width of two to three fingers).
• The bowel is then brought through the defect and secured with sutures.
• The abdominal incision is usually closed and dressed prior to maturing the stoma to avoid contaminating
the wound.
• In order to make appliance use easier, a protruding nipple is fashioned by everting the bowel.
• Three or four interrupted absorbable sutures are placed through the edge of the bowel, then through the
serosa, approximately 2 cm proximal to the edge, and then through the dermis (Brooke technique).
• After the stoma is everted, the mucocutaneous junction is sutured circumferentially with interrupted
absorbable suture

52. INFLAMMATORY BOWEL DISEASE

53. Epidemiology
• Includes ulcerative colitis, Crohn’s disease, and indeterminate colitis.
• Ulcerative colitis occurs in 8 to 15 people per 100,000 in the United
States and Northern Europe.
• Ulcerative colitis incidence peaks during the third decade of life and
again in the seventh decade of life.
• The incidence of Crohn’s disease is slightly lower, 1 to 5 people per
100,000.
• Crohn’s disease has a similar bimodal incidence, with most cases
occurring between ages 15 to 30 years and ages 55 to 60 years

54. Etiology
• Many different etiologies but none are proven.
• Environmental factor such as diet or infection.
• Smoking has been implicated in the etiology and exacerbation of
Crohn’s disease in particular.
• Alcohol and oral contraceptive use have also been implicated
• Family history may play a role because 10% to 30% of patients
• Autoimmune mechanism

55. Pathology and Differential Diagnosis
• Ulcerative colitis
• is a mucosal process in which the colonic mucosa and submucosa are infiltrated with
inflammatory cells
• Mucosa may be atrophic, and crypt abscesses are common
• Inflammatory pseudopolyps
• Foreshortened colon --- lead pipe colon
• Types
• Proctitis
• Proctosigmoiditis
• Left-sided colitis
• Pancolitis
• Does not involve the small intestine
• “backwash ileitis”
• Continuous involvement of the rectum and colon

56. Clinical presentation
• Bloody diarrhea and crampy abdominal pain
• Tenesmus
• Fulminant colitis or toxic megacolon
• Extraintestinal Manifestations
• Liver is a common site of extracolonic disease - Fatty infiltration/ cirrhosis/ Primary
sclerosing cholangitis/ Pericholangitis/ Bile duct carcinoma
• Arthritis - Sacroiliitis and ankylosing spondylitis
• Erythema nodosum -- in 5% to 15% of patients
• Pyoderma gangrenosum - erythematous plaque, papule, or bleb, usually located on
the pretibial region of the leg
• Ocular lesions -- Up to 10% of patients , uveitis, iritis, episcleritis, and conjunctivitis

57. Principles of Nonoperative Management.
• Salicylates
• First-line agents in the medical treatment of mild to moderate inflammatory bowel
disease
• Decrease inflammation by inhibition of cyclooxygenase and 5-lipoxygenase in the gut
mucosa
• Antibiotics – Metronidazole
• Corticosteroid
• Immunomodulating Agents - Azathioprine and 6-mercatopurine (6-MP)
• Onset of action of these drugs takes 6 to 12 weeks, and concomitant use of
corticosteroids almost always is required
• Immunosuppressive agent – Cyclosporine

58. • Indications for Surgery
• Massive life-threatening hemorrhage,
• Toxic megacolon, or fulminant colitis
• Refractory to medical therapy
• Deterioration in clinical condition or failure to improve within 24 to 48 hours
mandates surgery
• Total proctocolectomy with end ileostomy has been the “gold standard”
• Total proctocolectomy with continent ileostomy (Kock’s pouch)
• Restorative proctocolectomy with ileal pouch–anal anastomosis

59. DIVERTICULAR DISEASE

60. • Diverticulosis refers to the presence of diverticula without inflammation.
• Diverticulitis refers to inflammation and infection associated with diverticula.
• The majority of colonic diverticula are false diverticula in which the mucosa
and muscularis mucosa have herniated through the colonic wall.
• These diverticula occur between the teniae coli, at points where the main
blood vessels penetrate the colonic wall (presumably creating an area of
relative weakness in the colonic muscle).
• They are thought to be pulsion diverticula resulting from high intraluminal
pressure.
• Diverticular bleeding can be massive but usually is self-limited.
• True diverticula, which comprise all layers of the bowel wall, are rare and are
usually congenital in origin.
• The sigmoid colon is the most common site of diverticulosis.
• The etiology is poorly understood.

61. • The most accepted theory is that a lack of dietary fiber results in smaller stool
volume, requiring high intraluminal pressure and high colonic wall tension for
propulsion.
• Chronic contraction then results in muscular hypertrophy and development of
the process of segmentation in which the colon acts like separate segments
instead of functioning as a continuous tube.
• As segmentation progresses, the high pressures are directed radially toward the
colon wall rather than to development of propulsive waves that move stool
distally.
• The high radial pressures directed against the bowel wall create pulsion
diverticula.
• A loss of tensile strength and a decrease in elasticity of the bowel wall with age
have also been proposed etiologies.
• Although none of these theories has been proven, a high-fiber diet does appear
to decrease the incidence of diverticulosis.
• Although diverticulosis is common, most cases are asymptomatic, and
complications occur in the minority of people with this condition.

62. Inflammatory Complications (Diverticulitis)
• Refers to inflammation and infection associated with a diverticulum and is estimated
to occur in 10% to 25% of people with diverticulosis.
• Peridiverticular and pericolic infection results from a perforation (either macroscopic
or microscopic) of a diverticulum, which leads to contamination, inflammation, and
infection.
• The spectrum of disease ranges from mild, uncomplicated diverticulitis that can be
treated in the outpatient setting, to free perforation and diffuse peritonitis that
requires emergency laparotomy.
• Most patients present with left sided abdominal pain, with or without fever, and
leukocytosis.
• A mass may be present.
• Plain radiographs are useful for detecting free intra-abdominal air.
• CT scan is extremely useful for defining pericolic inflammation, phlegmon, or abscess.
• Contrast enemas and/or endoscopy are relatively contraindicated because of the risk
of perforation.
• The differential diagnosis includes malignancy, ischemic colitis, infectious colitis, and
inflammatory bowel disease

63. • Uncomplicated Diverticulitis
• Uncomplicated diverticulitis is characterized by left lower quadrant pain and tenderness.
• CT findings include pericolic soft tissue stranding, colonic wall thickening, and/or
phlegmon.
• Most patients with uncomplicated diverticulitis will respond to outpatient therapy with
broad-spectrum oral antibiotics and a low-residue diet.
• Antibiotics should be continued for 7 to 10 days.
• About 10% to 20% of patients with more severe pain, tenderness, fever, and leukocytosis
are treated in the hospital with parenteral antibiotics and bowel rest.
• Most patients improve within 48 to 72 hours.
• Failure to improve may suggest abscess formation.
• CT can be extremely useful in this setting, and many pericolic abscesses can be drained
percutaneously.
• Deterioration in a patient’s clinical condition and the development of peritonitis are
indications for laparotomy.
• Most patients with uncomplicated diverticulitis will recover without surgery, and 50% to
70% will have no further episodes.

64. • It has long been believed that the risk of complications increases with
recurrent disease.
• For this reason, elective sigmoid colectomy has often been
recommended after the second episode of diverticulitis, especially if the
patient has required hospitalization.
• Resection has often been recommended after the first episode in very
young patients and is often recommended after the first episode of
complicated diverticulitis.
• These general guidelines have been questioned in recent years, and
more recent studies suggest that the risk of complications and/or need
for emergent resection does not increase with recurrent disease.
• In the elective setting, a sigmoid colectomy with a primary anastomosis
is the procedure of choice.

65. • Complicated Diverticulitis
• Includes diverticulitis with abscess, obstruction, diffuse peritonitis (free
perforation), or fistulas between the colon and adjacent structures.
• Colo-vesical, Colo-vaginal, and Colo-enteric fistulas are long-term sequelae of
complicated diverticulitis.
• Hinchey staging system
• Stage I :- colonic inflammation with an associated pericolic abscess;
• Stage II :- colonic inflammation with a retroperitoneal or pelvic abscess;
• Stage III :- purulent peritonitis;
• Stage IV :- fecal peritonitis

66. Treatment
• Small abscesses (<2 cm in diameter) may be treated with parenteral
antibiotics.
• Larger abscesses are best treated with CT-guided percutaneous drainage
and antibiotics.
• Many of these patients will ultimately require resection, but percutaneous
drainage may allow a one-stage, elective procedure and may obviate the
need for colectomy if full recovery follows the drainage.
• Urgent or emergent laparotomy may be required if an abscess is
inaccessible to percutaneous drainage, if the patient’s condition
deteriorates or fails to improve, or if the patient presents with free intra-
abdominal air or peritonitis.
• Sigmoid colectomy with end colostomy and Hartmann’s pouch

67. Complication
• Intestinal Obstructive -- approximately 67% of patients
• Intestinal hemorrhage
• Intestinal fistula
• Giant diverticulosis

68. Right-Sided Diverticula
• Cecum and ascending colon
• True solitary diverticulum, which contains all layers of the bowel wall
• Thought to be congenital in origin.
• Right-sided diverticula occur more often in younger patients
• Mostly asymptomatic
• Right lower quadrant pain, similar as acute appendicitis.
• Single large diverticulum and minimal inflammation –
diverticulectomy ileocecal resection is preferred.

69. ADENOCARCINOMA AND POLYPS

70. Incidence
• Colorectal carcinoma is the most common malignancy of the
gastrointestinal tract.
• Over 140,000 new cases are diagnosed annually in the United States,
and more than 50,000 patients die of this disease each year.
• Colorectal cancer the third most lethal cancer in the United States.
• Similar in men and women

71. Epidemiology (Risk Factors)
• Aging
• Dominant risk factor
• After age 50 years
• Hereditary Risk Factors
• 80% sporadically, while 20% family history
• Environmental and Dietary Factors
• Carcinogenic - diets high in animal fat and low in fiber, high in saturated or
polyunsaturated fats, alcohol intake, Obesity and sedentary lifestyle
• Protective - diet high in vegetable fiber, Ingestion of calcium, selenium, vitamins A, C,
and E, carotenoids, and plant phenols
• Inflammatory Bowel Disease
• Chronic inflammation predisposes the mucosa to malignant changes

72. • Other Risk Factors
• Cigarette smoking is associated with an increased risk of colonic adenomas,
especially after more than 35 years of use.
• Patients with ureterosigmoidostomy are also at increased risk for both
adenoma and carcinoma formation
• Acromegaly has increased risk.
• Pelvic irradiation

73. Pathogenesis of Colorectal Cancer
• Genetic Defects
• Mutations may cause activation of oncogenes (K-ras) and/or inactivation of tumor
suppressor genes (APC, deleted in colorectal carcinoma [DCC], p53).
• Colorectal carcinoma is thought to develop from adenomatous polyps by accumulation of
these mutations in what has come to be known as the adenoma carcinoma sequence.
• The APC gene is a tumor suppressor gene. Mutations in both alleles are necessary to
initiate polyp formation.
• APC inactivation alone does not result in a carcinoma. Instead, this mutation sets the stage
for the accumulation of genetic damage that results in malignancy
• One of the most commonly involved genes in colorectal cancer is K-ras, epidermal growth
factor receptor (EGFR) pathway, is classified as a protooncogene
• MYH gene on chromosome 1p. MYH is a base excision repair gene.
• The tumor suppressor gene p53 has been well characterized in a number of malignancies

75. • Genetic Pathways.
• Three major genetic pathways:
• The loss of heterozygosity (LOH; chromosomal instability) pathway - chromosomal
deletions and tumor aneuploidy
• The microsatellite instability (MSI) pathway - errors in mismatch repair during DNA
replication
• The CpG island methylation (CIMP; serrated methylated) pathway

76. Polyps
• Polyp is a nonspecific clinical term that describes any projection from
the surface of the intestinal mucosa regardless of its histologic nature.
• Adenoma-carcinoma sequence.
• Classified as
• Neoplastic (tubular adenoma, villous adenoma, tubulovillous adenomas,
serrated adenomas/ polyps),
• Hyperplastic, hamartomatous (juvenile, Peutz-Jeghers, Cronkite-Canada)
• Inflammatory (pseudopolyp, benign lymphoid polyp).

77. Neoplastic Polyps
• Adenomatous polyps are common, occurring in up to 25% of the population older than 50
years of age in the United States.
• By definition, these lesions are dysplastic.
• The risk of malignant degeneration is related to both the size and type of polyp.
• Risk of malignancy
• Tubular adenomas - 5%
• Villous adenomas up to 40%
• Tubulovillous - 22%
• Invasive carcinomas are rare in polyps smaller than 1 cm
• The incidence increases with size.
• The risk of carcinoma in a polyp larger than 2 cm is 35% to 50%.
• Although most neoplastic polyps do not evolve to cancer, most colorectal cancers originate
as a polyp.
• It is this fact that forms the basis for secondary prevention strategies to eliminate colorectal
cancer by targeting the neoplastic polyp for removal before malignancy develops.

78. • Polyps may be pedunculated or sessile.
• Most pedunculated polyps are amenable to colonoscopic snare excision.
• Removal of sessile polyps is often more challenging.
• Special colonoscopic techniques, including saline lift, piecemeal snare excision,
and endoscopic mucosal resection facilitate successful removal of many sessile
polyps.
• For rectal sessile polyps, transanal operative excision is preferred because it
produces an intact, single pathology specimen that can be used to determine
the need for further therapy.
• Interpretation of the precise depth of invasion of a cancer arising in a sessile
polyp after piecemeal excision is often impossible.
• The site of sessile polypectomies should be marked by injection of India ink to
guide follow-up colonoscopy sessions to ensure that the polyp has been
completely removed and to facilitate identification of the involved bowel
segment should operative resection be necessary.
• Colectomy is reserved for cases in which colonoscopic removal is impossible,
such as large, flat lesions, or if a focus of invasive cancer is confirmed in the
specimen.

79. • Complications of polypectomy include
• Perforation and
• Bleeding.
• A small perforation (microperforation) in a fully prepared, stable patient
may be managed with bowel rest, broadspectrum antibiotics, and close
observation.
• Signs of sepsis, peritonitis, or deterioration in clinical condition are
indications for laparotomy.
• Bleeding may occur immediately after polypectomy or may be delayed.
• The bleeding will usually stop spontaneously, but colonoscopy may be
required to resnare a bleeding stalk or cauterize the lesion.
• Occasionally angiography and infusion of vasopressin may be necessary.
• Rarely, colectomy is required.

80. Hyperplastic Polyps
• Extremely common in the colon.
• Usually small (<5 mm) and show histologic characteristics of hyperplasia
without any dysplasia. Not considered premalignant, but cannot be
distinguished from adenomatous polyps colonoscopically and are therefore
often removed.
• In contrast, large hyperplastic polyps (>2 cm) may have a slight risk of
malignant degeneration.
• Moreover, large polyps may harbor foci of adenomatous tissue and dysplasia.
• Hyperplastic polyposis is a rare disorder in which multiple large hyperplastic
polyps occur in young adults.
• These patients are at slightly increased risk for the development of colorectal
cancer.

81. Serrated Polyps
• Recently recognized, histologically distinct group of neoplastic polyps.
• These lesions were long thought to be similar to hyperplastic polyps
with minimal malignant potential.
• However, it has become clear that some of these polyps will develop
into invasive cancers.
• In addition, a familial serrated polyposis syndrome has recently been
described.
• Serrated polyps should be treated like adenomatous polyps.

82. Hamartomatous Polyps (Juvenile Polyps)
• In contrast to adenomatous and serrated polyps, hamartomatous polyps
(juvenile polyps) usually are not premalignant.
• These lesions are the characteristic polyps of childhood but may occur at
any age.
• Bleeding is a common symptom, and intussusception and/or obstruction
may occur.
• Because the gross appearance of these polyps is identical to adenomatous
polyps, these lesions should also be treated by polypectomy.
• In contrast to adenomatous polyposis syndromes, these conditions are
often associated with mutation in PTEN.

83. Familial juvenile polyposis
• An autosomal dominant disorder in which patients develop hundreds of
polyps in the colon and rectum.
• Unlike solitary juvenile polyps, these lesions may degenerate into adenomas
and eventually carcinoma.
• Annual screening should begin between the ages of 10 and 12 years.
• Treatment is surgical and depends in part on the degree of rectal involvement.
• If the rectum is relatively spared, a total abdominal colectomy with ileorectal
anastomosis may be performed with subsequent close surveillance of the
retained rectum.
• If the rectum is carpeted with polyps, total proctocolectomy is the more
appropriate operation.
• These patients are candidates for ileal pouch–anal reconstruction to avoid a
permanent stoma

84. Peutz-Jeghers syndrome
• Characterized by polyposis of the small intestine and, to a lesser extent,
polyposis of the colon and rectum.
• Characteristic melanin spots are often noted on the buccal mucosa and lips of
these patients.
• The polyps of Peutz-Jeghers syndrome are generally considered to be
hamartomas and are not thought to be at significant risk for malignant
degeneration.
• However, carcinoma may occasionally develop.
• Because the entire length of the gastrointestinal tract may be affected, surgery
is reserved for symptoms such as obstruction or bleeding or for patients in
whom polyps develop adenomatous features.
• Screening consists of a baseline colonoscopy and upper endoscopy at age 20
years, followed by annual flexible sigmoidoscopy thereafter.

85. Cronkite-Canada syndrome
• A disorder in which patients develop gastrointestinal polyposis in
association with alopecia, cutaneous pigmentation, and atrophy of the
fingernails and toenails.
• Diarrhea is a prominent symptom, and vomiting, malabsorption, and
protein-losing enteropathy may occur.
• Most patients die of this disease despite maximal medical therapy, and
surgery is reserved for complications of polyposis such as obstruction.

86. Cowden’s syndrome
• An autosomal dominant disorder with hamartomas of all three
embryonal cell layers.
• Facial trichilemmomas, breast cancer, thyroid disease, and
gastrointestinal polyps are typical of the syndrome.
• Patients should be screened for cancers.
• Treatment is otherwise based on symptoms.

87. Inflammatory Polyps (Pseudopolyps)
• Most commonly in the context of inflammatory bowel disease, but may
also occur after amebic colitis, ischemic colitis, and schistosomal colitis.
• These lesions are not premalignant, but they cannot be distinguished
from adenomatous polyps based on gross appearance and therefore
should be removed.
• Microscopic examination shows islands of normal, regenerating mucosa
(the polyp) surrounded by areas of mucosal loss.
• Polyposis may be extensive, especially in patients with severe colitis, and
may mimic FAP

88. Familial Adenomatous Polyposis
• Rare autosomal dominant condition accounts for only about 1% of all colorectal
adenocarcinomas.
• Nevertheless, this syndrome has provided tremendous insight into the molecular
mechanisms underlying colorectal carcinogenesis.
• The genetic abnormality in FAP is a mutation in the APC gene, located on chromosome
5q.
• Of patients with FAP, APC mutation testing is positive in 75% of cases.
• While most patients with FAP will have a known family history of the disease, up to 25%
present without other affected family members.
• Clinically, patients develop hundreds to thousands of adenomatous polyps shortly after
puberty.
• The lifetime risk of colorectal cancer in FAP patients approaches 100% by age 50 years.
• Flexible sigmoidoscopy of first-degree relatives of FAP patients beginning at age 10 to 15
years has been the traditional mainstay of screening.

89. • Today, following genetic counseling, APC gene testing may be used to
screen family members, providing an APC mutation has been identified.
• If APC testing is positive in a relative of a patient with a known APC
mutation, annual flexible sigmoidoscopy beginning at age 10 to 15 years is
done until polyps are identified.
• If APC testing is negative, the relative can be screened starting at age 50
years per average risk guidelines.
• If APC testing is refused or unavailable, or if a mutation cannot be
identified, annual flexible sigmoidoscopy beginning at age 10 to 15 years is
performed until age 24 years.
• Screening flexible sigmoidoscopy is then done every 2 years until age 34
years, every 3 years until age 44 years, and then every 3 to 5 years.

90. • FAP patients are also at risk for the development of adenomas anywhere in
the gastrointestinal tract, particularly in the duodenum.
• Periampullary carcinoma is a particular concern.
• Upper endoscopy is therefore recommended for surveillance every 1 to 3
years beginning at age 25 to 30 years.
• Once the diagnosis of FAP has been made and polyps are developing,
treatment is surgical.
• Four factors affect the choice of operation:
1. Age of the patient;
2. Presence and severity of symptoms;
3. Extent of rectal polyposis; and
4. Presence and location of cancer or desmoid tumors.

91. • Three operative procedures can be considered:
1. Total proctocolectomy with an end (Brooke) ileostomy;
2. Total abdominal colectomy with ileorectal anastomosis; and
3. Restorative proctocolectomy with ileal pouch–anal anastomosis with or without a temporary
ileostomy.
• Most patients elect to have an ileal pouch–anal anastomosis in the absence of a distal
rectal cancer, a mesenteric desmoid tumor that prevents the ileum from reaching the
anus, or poor sphincter function.
• Mucosectomy has been advocated in patients with FAP undergoing ileal pouch–anal
anastomosis because of the risk of neoplasia in the anal transition zone, but the
requirement for this procedure remains controversial.
• Although patient satisfaction with this procedure remains high, function may not be
ideal, and up to 50% of patients experience some degree of incontinence.
• Total abdominal colectomy with an ileorectal anastomosis is also an option in these
patients, but requires vigilant surveillance of the retained rectum for development of
rectal cancer.
• There is increasing data suggesting that the administration of cyclooxygenase-2 (COX-
2) inhibitors (celecoxib, sulindac) may slow or prevent the development of polyps.

92. • FAP may be associated with extraintestinal manifestations such as
• congenital hypertrophy of the retinal pigmented epithelium,
• desmoid tumors,
• epidermoid cysts,
• mandibular osteomas (Gardner’s syndrome), and
• central nervous system tumors (Turcot’s syndrome).
• Desmoid tumors in particular, can make surgical management difficult
and are a source of major morbidity and mortality in these patients.
• Desmoid tumors are often hormone responsive, and growth may be
inhibited in some patients with tamoxifen.
• COX-2 inhibitors and nonsteroidal, anti-inflammatory drugs may also be
beneficial in this setting.

93. Attenuated Familial Adenomatous Polyposis
• AFAP is a recognized variant of FAP.
• Patients present later in life with fewer polyps (usually 10–100)
predominantly located in the right colon, when compared to classic FAP.
• Colorectal carcinoma develops in more than 50% of these patients, but
occurs later (average age, 55 years).
• Patients are also at risk for duodenal polyposis.
• However, in contrast to FAP, APC gene mutations are present in only
about 30% of patients with AFAP.
• When present, these mutations are expressed in an autosomal dominant
pattern.

94. • Mutations in MYH also result in the AFAP phenotype but are expressed in an
autosomal recessive pattern.
• It has been suggested that MYH mutations may be responsible for AFAP in
patients who do not have a detectable APC gene mutation.
• Genetic testing is often offered to patients with suspected AFAP. When positive,
genetic counseling and testing may be used to screen at-risk family members.
• If the family mutation is unknown, screening colonoscopy is recommended
beginning at age 13 to 15 years, then every 4 years to age 28 years, and then
every 3 years.
• These patients are often candidates for a total abdominal colectomy with
ileorectal anastomosis because the limited polyposis in the rectum can usually be
treated by colonoscopic snare excision.
• Prophylaxis with COX-2 inhibitors also may be appropriate.
• Because of the more subtle phenotype in these patients, it is important to rule
out other familial syndromes such as HNPCC (Lynch’s syndrome) and the more
common familial colorectal cancer.

95. Hereditary Nonpolyposis Colon Cancer (Lynch’s
Syndrome)
• More common than FAP, but is still extremely rare (1%–3% of all colon cancers).
• The genetic defects associated with HNPCC arise from errors in mismatch repair, the
phenotypic result being MSI.
• Autosomal dominant pattern
• Characterized by the development of colorectal carcinoma at an early age (average
age, 40–45 years).
• Approximately 70% of affected individuals will develop colorectal cancer.
• Cancers appear in the proximal colon more often than in sporadic colorectal cancer
and have a better prognosis regardless of stage.
• The risk of synchronous or metachronous colorectal carcinoma is 40%.
• HNPCC may also be associated with extracolonic malignancies, including endometrial
carcinoma, which is most common, and ovarian, pancreas, stomach, small bowel,
biliary, and urinary tract carcinomas.

96. • The diagnosis of HNPCC is made based on family history.
• The Amsterdam criteria for clinical diagnosis of HNPCC are three
affected relatives with histologically verified adenocarcinoma of the
large bowel (one must be a first-degree relative of one of the others) in
two successive generations of a family with one patient diagnosed
before age 50 years.
• The presence of other HNPCC-related carcinomas should raise the
suspicion of this syndrome.
• In a patient with an established diagnosis of colorectal cancer, tumor
testing for presence of mismatch repair gene products
(immunohistochemistry) and/ or MSI can sometimes serve as screening
for this syndrome.

97. • HNPCC results from mutations in mismatch repair genes, and like FAP, specific
mutations are associated with different phenotypes.
• For example, mutations in PMS2 or MSH6 result in a more attenuated form of HNPCC
when compared to mutations in other genes.
• MSH6 inactivation also appears to be associated with a higher risk for endometrial
cancer.
• Further significance of these specific mutations remains to be determined.
• Screening colonoscopy is recommended annually for at risk patients beginning at
either age 20 to 25 years or 10 years younger than the youngest age at diagnosis in the
family, whichever comes first.
• Because of the high risk of endometrial carcinoma, transvaginal ultrasound or
endometrial aspiration biopsy is also recommended annually after age 25 to 35 years.
• Because there is a 40% risk of developing a second colon cancer, total colectomy with
ileorectal anastomosis is recommended once adenomas or a colon carcinoma is
diagnosed.
• Annual proctoscopy is necessary because the risk of developing rectal cancer remains
high. Similarly, prophylactic hysterectomy and bilateral salpingo-oophorectomy should
be considered in women who have completed childbearing.

98. Familial Colorectal Cancer
• Nonsyndromic familial colorectal cancer accounts for 10% to 15% of patients with
colorectal cancer.
• The lifetime risk of colorectal cancer in a patient with no family history of this
disease (average-risk population) is approximately 6%, but rises to 12% if one
first-degree relative is affected and to 35% if two first-degree relatives are
affected.
• Age of onset also impacts risk, and a diagnosis before the age of 50 years is
associated with a higher incidence in family members.
• Screening colonoscopy is recommended every 5 years beginning at age 40 years
or beginning 10 years before the age of the earliest diagnosed patient in the
pedigree.
• While there are no specific genetic abnormalities that are associated with familial
colorectal cancer, any of the defects found in either the LOH pathway or MSI
pathway may be present in these patients.

99. Guidelines for Screening
• Current American Cancer Society guidelines advocate screening for
the average-risk population (asymptomatic, no family history of
colorectal carcinoma, no personal history of polyps or colorectal
carcinoma, no familial syndrome) beginning at age 50 years.
• Recommended procedures include yearly FOBT, flexible
sigmoidoscopy every 5 years, FOBT and flexible sigmoidoscopy in
combination, air-contrast barium enema every 5 years, or
colonoscopy every 10 years.
• Patients with other risk factors should be screened earlier and more
frequently.

102. Routes of Spread and Natural History
• Carcinoma of the colon and rectum arises in the mucosa.
• The tumor subsequently invades the bowel wall and eventually
adjacent tissues and other viscera.
• Tumors may become bulky and circumferential, leading to colon
obstruction.
• Local extension (especially in the rectum) may occasionally cause
obstruction of other organs such as the ureter.

103. • Regional lymph node involvement is the most common form of spread of
colorectal carcinoma and usually precedes distant metastasis or the
development of carcinomatosis.
• The likelihood of nodal metastasis increases with tumor size, poorly
differentiated histology, lymphovascular invasion, and depth of invasion.
• The T stage (depth of invasion) is the single most significant predictor of lymph
node spread.
• T1 and T2 are associated with lymph node metastasis in 5% to 20% of cases.
• T3 and T4 are likely to have lymph node metastasis in more than 50% of cases.
• Four or more involved lymph nodes predict a poor prognosis.
• The most common site of distant metastasis from colorectal cancer is the liver.
These metastases arise from hematogenous spread via the portal venous
system

105. Staging and Preoperative Evaluation
• Clinical Presentation.
• Symptoms of colon and rectal cancers are nonspecific and generally develop
when the cancer is locally advanced.
• The classic first symptoms are a change in bowel habits and rectal bleeding.
• Abdominal pain, bloating, and other signs of obstruction typically occur with
larger tumors and suggest more advanced disease.
• Because of the caliber of the bowel and the consistency of the stool, left-sided
tumors are more likely to cause obstruction than are right-sided tumors.
• Rectal tumors may cause bleeding, tenesmus, and pain.
• Alternatively, patients may be asymptomatic and/or present with unexplained
anemia, weight loss, or poor appetite.

106. • Staging
• The Dukes’ Classification and its Astler-Coller modification, have been
replaced by the tumornode-metastasis (TNM) staging system

107. TNM Staging

109. Therapy for Colonic Carcinoma
• Principles of Resection
• Remove the primary tumor along with its lymphovascular supply
• A minimum of 12 lymph nodes in the resected specimen are necessary for
adequate staging
• If the metastatic disease is low volume (isolated or potentially resectable liver
lesions) and the resection of the primary tumor is straightforward (segmental
abdominal colectomy), it is probably reasonable to proceed with resection.
• If the metastatic disease is high volume (carcinomatosis), especially if the
primary tumor is minimally symptomatic, the operation should be aborted in
order to facilitate early systemic chemotherapy.

110. Stage 0 (Tis, N0, M0).
• Polyps containing carcinoma in situ (high-grade dysplasia) carry no risk of
lymph node metastasis.
• However, the presence of high-grade dysplasia increases the risk of finding an
invasive carcinoma within the polyp.
• For this reason, these polyps should be excised completely, and pathologic
margins should be free of dysplasia.
• Most pedunculated polyps and many sessile polyps may be completely
removed endoscopically.
• These patients should be followed with frequent colonoscopy to ensure that
the polyp has not recurred and that an invasive carcinoma has not developed.
• In cases where the polyp cannot be removed entirely, a segmental resection is
recommended.

111. Stage I: The Malignant Polyp (T1, N0, M0)
• Occasionally a polyp that was thought to be benign will be found to harbor invasive
carcinoma after polypectomy.
• Treatment of a malignant polyp is based on the risk of local recurrence and the risk of
lymph node metastasis.
• The risk of lymph node metastases depends primarily on the depth of invasion.
• Invasive carcinoma in the head of a pedunculated polyp with no stalk involvement
carries a low risk of metastasis (<1%) and may be completely resected endoscopically.
• However, lymphovascular invasion, poorly differentiated histology, or tumor within 1
mm of the resection margin greatly increases the risk of local recurrence and
metastatic spread.
• Segmental colectomy is then indicated.
• Invasive carcinoma arising in a sessile polyp extends into the submucosa and is
usually best treated with segmental colectomy

113. Stages I and II: Localized Colon Carcinoma
(T1-3, N0, M0)
• The majority of patients with stages I and II colon cancer will be cured with
surgical resection.
• Few patients with completely resected stage I disease will develop either
local or distant recurrence, and adjuvant chemotherapy does not improve
survival in these patients.
• However, up to 46% of patients with completely resected stage II disease will
ultimately die from colon cancer.
• For this reason, adjuvant chemotherapy has been suggested for selected
patients with stage II disease (young patients, tumors with “high-risk”
histologic findings).
• It remains controversial as to whether chemotherapy improves survival rates
in these patients.
• Molecular profiling holds promise for improving patient selection in these
early cancers.

114. Stage III: Lymph Node Metastasis (Tany, N1,
M0)
• Patients with lymph node involvement are at significant risk for both local and
distant recurrence, and adjuvant chemotherapy has been recommended
routinely in these patients.
• 5-Fluorouracil–based regimens (with leucovorin) and oxaliplatin (FOLFOX)
reduce recurrences and improve survival in this patient population.
• It is important to note, however, that a subgroup of patients with stage III
disease will do well without chemotherapy.
• MSI status in particular predicts good prognosis.
• Subset analysis from the CRYSTAL trial has shown that patients with MSI-high
stage III disease do not benefit from 5-fluorouracil–based chemotherapy.
• Molecular profiling, therefore, may be helpful in determining which stage III
patients can safely avoid systemic chemotherapy

115. Stage IV: Distant Metastasis (Tany, Nany, M1)
• Survival is extremely limited in stage IV colon carcinoma.
• However, unlike many other malignancies, highly selected patients with isolated, resectable
metastases may benefit from resection (metastasectomy).
• The most common site of metastasis is the liver.
• Of patients with systemic disease, approximately 15% will have metastases limited to the liver.
• Of these, 20% are potentially resectable for cure.
• Survival is improved in these patients (20% –40% 5-year survival) when compared to patients who do not
undergo resection.
• Hepatic resection of synchronous metastases from colorectal carcinoma may be performed as a combined
procedure or in two stages.
• All patients require adjuvant chemotherapy.
• The second most common site of metastasis is the lung,
• occurring in approximately 20% of patients with colorectal carcinoma.
• Although very few of these patients will be potentially resectable, among those who are (about 1%–
2% of all colorectal cancer patients), long-term survival benefit is approximately 30% to 40%.
• There are limited reports of successful resection of metastases in other sites (ovary and
retroperitoneum are most common).

116. Therapy for Rectal Carcinoma
• Principles of Resection
• Complete resection of the primary tumor, its lymphatic bed, and any
other involved organ apply to surgical resection of rectal carcinoma.
• Difficult to achieve negative radial margins in rectal cancers.
• Therapeutic decisions, therefore, are based on the location and depth
of the tumor and its relationship to other structures in the pelvis

117. Local Therapy
• The distal 10 cm of the rectum.
• Transanal excision (full thickness or mucosal) is an excellent approach
for noncircumferential, benign, villous adenomas of the rectum.
• Transanal endoscopic microsurgery (TEM) and transanal minimally
invasive surgery (TAMIS) make use of a specially designed
proctoscope, magnifying system, and instruments similar to those
used in laparoscopy to allow local excision of lesions higher in the
rectum (up to 15 cm).
• Ablative techniques, such as electrocautery or endocavitary radiation

118. Radical Resection
• Removal of the involved segment of the rectum along with its
lymphovascular supply.
• 2-cm distal mural margin for curative resections.
• Total mesorectal excision (TME)
• Sharp dissection along anatomic planes
• For upper rectal or rectosigmoid resections, a partial mesorectal excision of at least 5
cm distal to the tumor appears adequate.
• TME both decreases local recurrence rates and improves long-term survival rates.
• Moreover, this technique is associated with less blood loss and less risk to the pelvic
nerves and presacral plexus than is blunt dissection.
• The principles of TME should be applied to all radical resections for rectal cancer.

120. Follow-Up and Surveillance
• Colonoscopy should be performed within 12 months after the
diagnosis of the original cancer
• If that study is normal, colonoscopy should be repeated every 3 to 5
years thereafter.
• CEA is often followed every 3 to 6 months for 2 years.
• CT scans are often performed annually for 5 years,

121. Treatment of Recurrent Colorectal Carcinoma
• Between 20% and 40% of patients develop recurrent disease.
• Most recurrences occur within the first 2 years after the initial
diagnosis, but preoperative chemoradiation therapy may delay
recurrence.
• Salvage surgery

122. Rectal Prolapse
• Circumferential, full-thickness protrusion of the rectum through the anus
• “first-degree” prolapse, “complete” prolapse, or procidentia
• Internal intussusception - Internal prolapse
• Female-to-male ratio of 6:1.
• Seventh decade of life.
• Symptoms
• Tenesmus
• Sensation of tissue protruding from the anus that may or may not spontaneously reduce
• Sensation of incomplete evacuation.
• Mucus discharge and leakage may accompany the protrusion
• Colonoscopy, air-contrast barium enema, or CT colonography to exclude
neoplasms or diverticular disease

123. • The primary therapy for rectal prolapse is surgery - abdominal or perineal
• Abdominal operations have taken three major approaches:
• (a) reduction of the perineal hernia and closure of the cul-de-sac (Moschowitz
repair);
• (b) fixation of the rectum, either with a prosthetic sling (Ripsten and Wells
rectopexy) or by suture rectopexy; or
• (c) resection of redundant sigmoid colon
• Perineal approaches have focused on tightening the anus with a variety of
prosthetic materials,
• Reefing the rectal mucosa (Delorme procedure), or
• Resecting the prolapsed bowel from the perineum (perineal rectosigmoidectomy or
Altemeier procedure)

124. Volvulus
• A volvulus is a twisting or axial rotation of a portion of bowel about its
mesentery.
• The sigmoid colon is involved in up to 90% of cases, but volvulus can
involve the cecum (<20%) or transverse colon.
• Presentation
• Fulminant: sudden onset, severe pain, early vomiting, rapidly deteriorating
clinical course
• Indolent: insidious onset, slow progressive course, less pain, late vomiting.

125. • Sigmoid Volvulus
• Sigmoid volvulus produces a characteristic bent inner tube or coffee bean
appearance, with the convexity of the loop lying in the right upper quadrant
(opposite the site of obstruction).
• Gastrografin enema shows a narrowing at the site of the volvulus and a
pathognomonic bird’s beak.
• Unless there are obvious signs of gangrene or peritonitis, the initial management of
sigmoid volvulus is resuscitation followed by endoscopic detorsion.
• Detorsion is usually most easily accomplished by using a rigid proctoscope, but a
flexible sigmoidoscope or colonoscope may also be effective.
• A rectal tube may be inserted to maintain decompression.
• Although these techniques are successful in reducing sigmoid volvulus in the
majority of patients, the risk of recurrence is high (up to 40%).
• For this reason, an elective sigmoid colectomy should be performed after the patient
has been stabilized and undergone an adequate bowel preparation.
• Sigmoid colectomy with end colostomy (Hartmann’s procedure) may be the safest
operation to perform.

126. • Cecal Volvulus
• Results from non fixation of the right colon.
• In the majority of cases, rotation occurs around the ileocolic blood vessels and
vascular impairment occurs early, although 10% to 30% of the cecum folds upon
itself (cecal bascule).
• Plain X-rays of the abdomen show a characteristic kidney-shaped, air-filled
structure in the left upper quadrant (opposite the site of obstruction), and a
Gastrografin enema confirms obstruction at the level of the volvulus.
• Unlike sigmoid volvulus, cecal volvulus can almost never be detorsed
endoscopically.
• Moreover, because vascular compromise occurs early in the course of cecal
volvulus, surgical exploration is necessary when the diagnosis is made.
• Right hemicolectomy with a primary ileocolic anastomosis can usually be
performed safely and prevents recurrence.
• Simple detorsion or detorsion and cecopexy are associated with a high rate of
recurrence.

127. • Transverse Colon Volvulus.
• Extremely rare.
• Nonfixation of the colon and chronic constipation with megacolon
may predispose to transverse colon volvulus.

128. Megacolon
• Megacolon describes a chronically dilated, elongated, hypertrophied large bowel.
• Megacolon may be congenital or acquired and is usually related to chronic mechanical or
functional obstruction.
• In general, the degree of megacolon is related to the duration of obstruction.
• Evaluation must always include examination of the colon and rectum (either endoscopically or
radiographically) to exclude a surgically correctable mechanical obstruction.
• Congenital megacolon caused by Hirschsprung’s disease results from the failure of migration
of neural crest cells to the distal large intestine.
• The resulting absence of ganglion cells in the distal colon results in a failure of relaxation and
causes a functional obstruction.
• The proximal, healthy bowel becomes progressively dilated.
• Surgical resection of the aganglionic segment is curative.
• Although Hirschsprung’s disease primarily is a disease of infants and children, it occasionally
presents later in adulthood, especially if an extremely short segment of the bowel is affected
(ultrashort-segment Hirschsprung’s disease).

129. • Acquired megacolon
• may result from infection or chronic constipation.
• Infection with the protozoan Trypanosoma cruzi (Chagas’ disease) destroys
ganglion cells and produces both megacolon and megaesophagus.
• Chronic constipation from slow transit or secondary to medications
(especially anticholinergic medications) or neurologic disorders (paraplegia,
poliomyelitis, amyotrophic lateral sclerosis, multiple sclerosis) may produce
progressive colonic dilatation.
• Diverting ileostomy or subtotal colectomy with an ileorectal anastomosis is
occasionally necessary in these patients.

130. Colonic pseudo-obstruction (Ogilvie’s
syndrome)
• is a functional disorder in which the colon becomes massively dilated in the
absence of mechanical obstruction.
• Pseudo-obstruction most commonly occurs in hospitalized patients and is
associated with the use of narcotics, bed rest, and comorbid disease.
• Pseudoobstruction is thought to result from autonomic dysfunction and
severe adynamic ileus.
• The diagnosis is made based on the presence of massive dilatation of the
colon (usually predominantly the right and transverse colon) in the absence of
a mechanical obstruction.
• Initial treatment consists of cessation of narcotics, anticholinergics, or other
medications that may contribute to ileus.
• Strict bowel rest and intravenous hydration are crucial

131. • Intravenous neostigmine (an acetylcholinesterase inhibitor) also is
extremely effective in decompressing the dilated colon and is
associated with a low rate of recurrence (20%).

132. Ischemic Colitis
• Risk factors include vascular disease, diabetes mellitus, vasculitis,
hypotension, and tobacco use. In addition, ligation of the inferior
mesenteric artery during aortic surgery predisposes to colonic
ischemia. Occasionally, thrombosis or embolism may cause ischemia.
• Splenic flexure is the most common site of ischemic colitis, any
segment of the colon may be affected.
• The rectum is relatively spared because of its rich collateral
circulation.

133. • In mild cases, patients may have diarrhea (usually bloody) without abdominal
pain.
• With more severe ischemia, intense abdominal pain (often out of proportion to
the clinical examination), tenderness, fever, and leukocytosis are present.
Peritonitis and/or systemic toxicity are signs of full thickness ne
• The diagnosis of ischemic colitis is often based on the clinical history and physical
examination.
• Plain films may reveal thumb printing, which results from mucosal edema and
submucosal hemorrhage.
• CT often shows nonspecific colonic wall thickening and pericolic fat stranding.
• Angiography is usually not helpful because major arterial occlusion is rare.
• While sigmoidoscopy may reveal characteristic dark, hemorrhagic mucosa, the
risk of precipitating perforation is high.
• For this reason, sigmoidoscopy is relatively contraindicated in any patient with
significant abdominal tenderness.
• Contrast studies (Gastrografin or barium enema) are similarly contraindicated
during the acute phase of ischemic colitis and perforation

134. • Treatment of ischemic colitis
• Depends on clinical severity.
• Unlike ischemia of the small bowel, the majority of patients with ischemic colitis can be
treated medically.
• Bowel rest and broad-spectrum antibiotics are the mainstay of therapy, and 80% of patients
will recover with this regimen.
• Hemodynamic parameters should be optimized, especially if hypotension and low flow
appear to be the inciting cause.
• Long-term sequelae include stricture (10%–15%) and chronic segmental ischemia (15%–
20%).
• Colonoscopy should be performed after recovery to evaluate strictures and to rule out other
diagnoses such as inflammatory bowel disease or malignancy.
• Failure to improve after 2 to 3 days of medical management, progression of symptoms, and
deterioration in clinical condition are indications for surgical exploration.
• In this setting, all necrotic bowel should be resected.
• Primary anastomosis should be avoided.
• Occasionally, repeated exploration (a second-look operation) may be necessary

135. Pseudomembranous Colitis (Clostridium
difficile Colitis)
• Caused by C. difficile, a gram positive anaerobic bacillus.
• C. difficile colitis is extremely common and is the leading cause of nosocomial
acquired diarrhea.
• The spectrum of disease ranges from watery diarrhea to fulminant, life-threatening
colitis.
• C. difficile is carried in the large intestine of many healthy adults.
• Colitis is thought to result from overgrowth of this organism after depletion of the
normal commensal flora of the gut with the use of antibiotics.
• Although clindamycin was the first antimicrobial agent associated with C. difficile
colitis, almost any antibiotic may cause this disease.
• Moreover, although the risk of C. difficile colitis increases with prolonged antibiotic
use, even a single dose of an antibiotic may cause the disease.
• Immunosuppression, medical comorbidities, prolonged hospitalization or nursing
home residence, and bowel surgery increase the risk.

136. • The pathogenic changes associated with C. difficile colitis result from
production of two toxins: toxin A (an enterotoxin) and toxin B (a
cytotoxin).
• Diagnosis of this disease was traditionally made by culturing the
organism from the stool.
• Detection of one or both toxins (either by cytotoxic assays or by
immunoassays) has proven to be more rapid, sensitive, and specific.
• The diagnosis may also be made endoscopically by detection of
characteristic ulcers, plaques, and pseudomembranes.

137. • Management should include immediate cessation of the offending
antimicrobial agent.
• Patients with mild disease (diarrhea but no fever or abdominal pain) may
be treated as outpatients with a 10-day course of oral metronidazole.
• Oral vancomycin is a second-line agent used in patients allergic to
metronidazole or in patients with recurrent disease.
• More severe diarrhea associated with dehydration and/or fever and
abdominal pain is best treated with bowel rest, intravenous hydration, and
oral metronidazole or vancomycin.
• Proctosigmoiditis may respond to vancomycin enemas.
• Reintroduction of normal flora by ingestion of probiotics or stool
transplantation

138. Hemorrhoids
• Cushions of submucosal tissue containing venules, arterioles, and
smooth muscle fibers that are located in the anal canal.
• Three hemorrhoidal cushions are found in the left lateral, right
anterior, and right posterior positions.
• Hemorrhoids are thought to function as part of the continence
mechanism and aid in complete closure of the anal canal at rest.
• Bleeding, thrombosis, and symptomatic hemorrhoidal prolapse

139. • External hemorrhoids
• are located distal to the dentate line and are covered with anoderm.
• Because the anoderm is richly innervated, thrombosis of an external hemorrhoid
may cause significant pain.
• It is for this reason that external hemorrhoids should not be ligated or excised
without adequate local anesthetic.
• A skin tag is redundant fibrotic skin at the anal verge, often persisting as the
residua of a thrombosed external hemorrhoid.
• Skin tags are often confused with symptomatic hemorrhoids.
• External hemorrhoids and skin tags may cause itching and difficulty with hygiene if
they are large.
• Treatment of external hemorrhoids and skin tags is only indicated for symptomatic
relief.

140. • Internal hemorrhoids
• are located proximal to the dentate line and covered by insensate anorectal mucosa.
• Internal hemorrhoids may prolapse or bleed, but rarely become painful unless they develop
thrombosis and necrosis (usually related to severe prolapse, incarceration, and/or
strangulation).
• Internal hemorrhoids are graded according to the extent of prolapse.
• First degree hemorrhoids bulge into the anal canal and may prolapse beyond the dentate line on
straining.
• Second-degree hemorrhoids prolapse through the anus but reduce spontaneously.
• Third-degree hemorrhoids prolapse through the anal canal and require manual reduction.
• Fourth-degree hemorrhoids prolapse but cannot be reduced and are at risk for strangulation.
• Hemorrhoidectomy is often required for large, symptomatic, combined hemorrhoids
• Medical Therapy.
• Bleeding from first- and second-degree hemorrhoids often improves with the addition of dietary fiber,
stool softeners, increased fluid intake, and avoidance of straining.
• Associated pruritus often may improve with improved hygiene.
• Many over-the-counter topical medications are desiccants and are relatively ineffective for treating
hemorrhoidal symptoms.

141. • Rubber Band Ligation.
• Persistent bleeding from first-, second-, and selected third-degree hemorrhoids may
be treated by rubber band ligation.
• Mucosa located 1 to 2 cm proximal to the dentate line is grasped and pulled into a
rubber band applier.
• After firing the ligator, the rubber band strangulates the underlying tissue, causing
scarring and preventing further bleeding or prolapse.
• Only one or two quadrants are banded per visit.
• Complication
• Severe pain
• Urinary retention,
• Infection
• Bleeding .
• Necrotizing infection is an uncommon

142. • Infrared Photocoagulation.
• An effective office treatment for small first- and second-degree hemorrhoids.
• The instrument is applied to the apex of each hemorrhoid to coagulate the
underlying plexus.
• All three quadrants may be treated during the same visit.
• Larger hemorrhoids and hemorrhoids with a significant amount of prolapse are
not effectively treated with this technique.
• Sclerotherapy.
• The injection of bleeding internal hemorrhoids with sclerosing agents is another
effective office technique for treatment of first-, second-, and some third-degree
hemorrhoids.
• One to 3 mL of a sclerosing solution (phenol in olive oil, sodium morrhuate, or
quinine urea) is injected into the submucosa of each hemorrhoid.
• Few complications are associated with sclerotherapy, but infection and fibrosis
have been reported

143. • Excision of Thrombosed External Hemorrhoids.
• Acutely thrombosed external hemorrhoids generally cause intense pain and a
palpable perianal mass during the first 24 to 72 hours after thrombosis.
• The thrombosis can be effectively treated with an elliptical excision performed
in the office under local anesthesia.
• Because the clot is usually loculated, simple incision and drainage is rarely
effective.
• After 72 hours, the clot begins to resorb, and the pain resolves spontaneously.
• Excision is unnecessary, but sitz baths and analgesics are often helpful.

144. Operative Hemorrhoidectomy
• Closed Submucosal Hemorrhoidectomy.
• The Parks or Ferguson hemorrhoidectomy involves resection of hemorrhoidal tissue and
closure of the wounds with absorbable suture.
• Open Hemorrhoidectomy.
• This technique, often called the Milligan and Morgan hemorrhoidectomy, follows the same
principles of excision, but the wounds are left open and allowed to heal by secondary
intention.
• Whitehead’s Hemorrhoidectomy.
• Whitehead’s hemorrhoidectomy involves circumferential excision of the hemorrhoidal
cushions just proximal to the dentate line.
• Procedure for Prolapse and Hemorrhoids/Stapled Hemorrhoidectomy
• No excision of hemorrhoidal tissue, but instead pexes the redundant mucosa above the
dentate line.
• Doppler-Guided Hemorrhoidal Artery Ligation

145. • Complication of hemorrhoidectomy
• Urinary retention
• Infection
• Bleeding
• Necrotising infection
• Anal stenosis
• Incontinence
• Ectropion

146. Anal Fissure
• A tear in the anoderm distal to the dentate line.
• The pathophysiology of anal fissure is thought to be related to trauma
from either the passage of hard stool or prolonged diarrhea.
• Symptoms
• tearing pain with defecation and hematochezia.
• First-line therapy to minimize anal trauma includes bulk agents, stool
softeners, and warm sitz baths.
• Surgical sphincterotomy for chronic fissure

147. •THANK YOU