This talk was given at the 2019 European Society of Regional Anaesthesia Meeting in Bilbao, Spain.
In this Talk, we cover the potential mechanisms behind how fascial plane blocks might work and also discuss why there may be such variation in clinical effect.
20. Soft collagen-containing
loose & dense fibrous connective tissue
Permeates whole body
Skin
Superficial fascia
Deep Fascia
(multilayer)
Muscle & related fasciaSuperficial adipose tissue
Deep adipose tissue
Loose connective tissue
What is Fascia?
@amit_pawa
21. Deep Fascia
Multiple layers
Extends through whole body
Target for Fascial plane blocks
Forms sheaths for nerves/vessels/organs
Independent of muscle below
@amit_pawa
26. Parietal pleura
Ventral ramus
Dorsal ramus
ESM
Lateral cutaneous branch of intercostal nerve
Anterior cutaneous branch of intercostal nerve
Transversus thoracis muscle
Pec. major
Pec. minor
Inn IMInt IMExt IM
Serratus anterior muscle
Latissimus dorsi muscle
Lateral and medial pectoral nerves
PEC I
PEC II
SAP Blocks
Pecto-Intercostal Fascial Block
RLBESP TPVBMTP
Pectoral branch of thoracoacromial artery
SIFB
Rhomboid
Rhomboid
Intercostal Block
Subserratus
Plane Block
RISS
Dr Ann Barron
@Ann_Barron1
PIFB: Pecto-Intercostal Fascial Block
SIFB: Serratus intercostal Fascial block
SAP: Serratus Anterior Plane
RISS: Rhomboid Intercostal & SubSerratus Plane Block
MTP: Mid-Point Transverse Process to Pleura
ESP: Erector Spinae
TPVB: Thoracic ParaVertebral Block
RLB: RetroLaminar Block
@amit_pawa
27. Parietal pleura
Lateral cutaneous branch of intercostal nerve
Anterior cutaneous branch of intercostal nerve
Transversus thoracis muscle
Pec. major
Pec. minor
Latissimus dorsi muscle
Lateral and medial pectoral nerves
PEC I
PEC II
SAP Blocks
Pecto-Intercostal Fascial Block
Pectoral branch of thoracoacromial artery
SIFB
33. 3. Biomechanical properties
Pumping mechanism due to muscle tendons?
Contractile elements within fascia?
-> Variable/extensive dermatomal spread?
Effect of:
Depth of Anaesthesia & Muscle Relaxation?
@amit_pawa
34. Nerve elements may lie within the fascia
A & C Fibres
Wide Dynamic Range neurons
Mechanoreceptors
Do these influence Fascial plane blocks?
4. Local Fascial Innervation
@amit_pawa
35. Not All fascias are the same
Number of layers
Pectoral region - 1
The Limbs - 2 or 3
Middle Thoracolumbar 3
Function & Mobility More mobile may
increase LA spread
Surrounding structures
Lungs/liver/spleen
IPPV vs SV
@amit_pawa
38. Even when you get in the correct
plane - does the LA stay there?
Yang H, Kim SH Injectate spread in interfascial plane block: a microscopic finding
Regional Anesthesia & Pain Medicine Published Online First: 05 July 2019.
doi: 10.1136/rapm-2019-100693
@amit_pawa
39. Even when you get in the correct
plane - does the LA stay there?
Yang H, Kim SH Injectate spread in interfascial plane block: a microscopic finding
Regional Anesthesia & Pain Medicine Published Online First: 05 July 2019.
doi: 10.1136/rapm-2019-100693
“The Fascial plane is not a closed space”
"Injectate spread into the internal oblique &
transversus abdominus muscle via the Perimysium”
Could this affect the amount of LA
available to act?
@amit_pawa
41. What can we say so far?
Not all fascial plane blocks are equal
Not all fascial plane blocks work (the same way!)
Fascial plane blocks have variable efficacy
Identifying the correct plane is not always easy
(“Seeker” solution)
@amit_pawa
43. (a)
(b)
Anaesthesia, 2011, 66, pages 1023–1030
..............................................................................................
rsal extension with an anterior subcostal
ock. (b) Bilateral mid-axillary ultra-
(b)
Figure 8 (a) Bilateral ultrasound via the posterior approac
showing extension along the quadratus lumborum muscle
ORIGINAL ARTICLE
Studies on the spread of local anaesthetic solution in
transversus abdominis plane blocks*
J. Carney,1
O. Finnerty,1
J. Rauf,1
D. Bergin,4
J. G. Laffey2
and J. G. Mc Donnell3
1 Registrar, 2 Professor, 3 Senior Clinical Lecturer, Department of Anaesthesia and Intensive Care Medicine,
4 Senior Clinical Lecturer, Department of Radiology, Galway University Hospitals, Galway, Ireland
Summary
The extent of analgesia provided by transversus abdominis plane blocks depends upon the site of
injection and pattern of spread within the plane. There are currently a number of ultrasound-
guided approaches in use, including an anterior oblique-subcostal approach, a mid-axillary
approach and a more recently proposed posterior approach. We wished to determine whether the
site of injection of local anaesthetic into the transversus abdominis plane affects the spread of the
local anaesthetic within that plane, by studying the spread of a local anaesthetic and contrast
solution in four groups of volunteers. The first group underwent the classical landmark-based
transversus abdominis plane block whereby two different volumes of injectate were studied:
0.3 ml.kg)1
vs 0.6 ml.kg)1
. The second group underwent transversus abdominis plane block using
the anterior subcostal approach. The third group underwent transversus abdominis plane block
using the mid-axillary approach. The fourth group underwent transversus abdominis plane block
using the posterior approach, in which local anaesthetic was deposited close to the antero-lateral
border of the quadratus lumborum. All volunteers subsequently underwent magnetic resonance
imaging at 1, 2 and 4 h following each block to determine the spread of local anaesthetic over time.
The studies demonstrated that the anterior subcostal and mid-axillary ultrasound approaches res-
ulted in a predominantly anterior spread of the contrast solution within the transversus abdominis
plane and relatively little posterior spread. There was no spread to the paravertebral space with the
anterior subcostal approach. The mid-axillary transversus abdominis plane block gave faint contrast
ORIGINAL ARTIC
Studies on the sp
transversus abdom
1 1
Anaesthesia, 2011, 66, pages 1023–1030
..............................................................
US- Guided Posterior TAP spreads to PVS
@amit_pawa
44. SCIENTIFIC ARTICLE
Axillary local anesthetic spread after the thoracic
interfacial ultrasound block --- a cadaveric and
radiological evaluation
Patricia Alfaro de la Torrea
, Jerry Wayne Jones Jr.b
, Servando López Álvarezc
,
Paula Diéguez Garciac
, Francisco Javier Garcia de Migueld
, Eva Maria Monzon Rubioe
,
Federico Carol Boerisf
, Monir Kabiri Sacramentog
, Osmany Duanyh
,
Mario Fajardo Pérezi,∗
, Borja de la Quintana Gordonj
a
Tajo University Hospital, Madrid, Spain
b
University of Tennessee Health Science Center/Regional One Health, College of Medicine, Department of Anesthesiology, TN,
USA
c
Hospital Complexo Hospitalario de A Coru˜na, Coru˜na, Spain
d
Hospital General de Segovia, Departamento de Anestesia, Segovia, Spain
e
Tajo University Hospital, Departamento de Anestesia, Madrid, Spain
f
Hospital Universitario Parc Tauli Sabadell, Sabadell, Spain
g
Hospital Universitario de Guadalajara, Guadalajara, Spain
h
Primary Care and Chronic Pain Management Attending, Department of Veterans Affairs, Muskogee, OK, USA
i
Hospital Universitario de Móstoles, Madrid, Spain
j
Hospital Universitario de Móstoles, Departamento de Anestesia, Madrid, Spain
Received 23 February 2015; accepted 14 April 2015
Available online 22 June 2016
KEYWORDS
Anesthesia,
conduction;
Axilla;
Intercostal muscles;
Brachial plexus block;
Intercostal nerves;
Lymph node excision;
Ultrasonography
Abstract
Background: Oral opioid analgesics have been used for management of peri- and postoperative
analgesia in patients undergoing axillary dissection. The axillary region is a difficult zone to block
and does not have a specific regional anesthesia technique published that offers its adequate
blockade.
Methods: After institutional review board approval, anatomic and radiological studies were
conducted to determine the deposition and spread of methylene blue and local anesthetic
injected respectively into the axilla via the thoracic inter-fascial plane. Magnetic Resonance
Imaging studies were then conducted in 15 of 34 patients scheduled for unilateral breast surgery
that entailed any of the following: axillary clearance, sentinel node biopsy, axillary node biopsy,
or supernumerary breasts, to ascertain the deposition and time course of spread of solution
within the thoracic interfascial plane in vivo.
Rev Bras Anestesiol. 2017;67(6):555---564
REVISTA
BRASILE
ANESTE
SCIENTIFIC ARTICLE
Axillary local anesthetic
cal anesthetic spread after the thoracic interfacial 559
to identify, in the surface plane, the pectoralis muscles,
the toracho-achromial artery and the cephalic vein that lie
between them. In the deep plane, the SAM is identified,
resting on the ribs. The needle is then introduced in-plane
from medial to lateral, and its tip is placed between the
SAM and the External Intercostal muscle at level of sec-
ond rib. Twenty mL of Levobupivacaine 0.25% + Epinephrine
1:200,000 were injected under direct ultrasound visualiza-
tion in real time, fragmenting the total volume, aspirating
every 3 mL to reduce the risk of intravascular injection
and minimizing the patient discomfort on hydrodissection
(Fig. 2A).
Study 1: determination of injectate spread during
SIFB using MRI
The aim of this study was to determine the axillary spread
of the injectate within the SIFB anterior approach. Our
image study consisted of a MRI done immediately after
LA injection. Our radiologist used MRI sequences to show
T2---weighed, fat-suppressed images, making axial and coro-
nal thoracic sections from the supraclavicular regions to the
inframammary crease. The same radiologist, proficient in
thoracic MRI, analyzed the images and issued a report of
the spread of the LA injectate in the interfascial thoracic
“PECS" spreads to
Intercostobrachial
Medial Brachiocutaneous
Lateral Cutaneous Branches T1-3
@amit_pawa
47. ESP Mechanism?
PVB spread by Proxy?
jected dyes into the back muscles after retrolaminar (RL, right) and ESP block (ESP, left).
columbar fascia covering the erector spinae muscle was revealed. (b) The muscle fibre
The spread pattern of the dyes in the vertebral laminae was seen after removal of all bac
ocostalis; Lo, longissimus thoracis).
(b)
(c)
Anaesthesia 2018, 73, 1244–1250
Original Article
Comparison of injectate spread and nerve involvement
between retrolaminar and erector spinae plane blocks in
the thoracic region: a cadaveric study
H.-M. Yang,1
Y. J. Choi,2
H.-J. Kwon,3
J. O,3
T. H. Cho3
and S. H. Kim4
1 Assistant Professor, 2 Instructor, 3 Research Assistant, Department of Anatomy, 4 Associate Professor, Department of
Anaesthesiology and Pain Medicine, Anaesthesia and Pain Research Institute, Yonsei University College of Medicine,
Seoul, Korea
Summary
Although different injection locations for retrolaminar and erector spinae plane blocks have been described,
the two procedures have a similar anatomical basis. In this cadaveric study we compared anatomical spread of
dye in the thoracic region following these two procedures. Following randomisation, 10 retrolaminar blocks
and 10 erector spinae plane blocks were performed on the left or right sides of 10 unembalmed cadavers. For
each block, 20 ml of dye solution was injected at the T5 level. The back regions were dissected and the
involvement of the thoracic spinal nerve was also investigated. Twenty blocks were successfully completed. A
consistent vertical spread, with deep staining between the posterior surface of the vertebral laminae and the
overlaying transversospinalis muscle was observed in all retrolaminar blocks. Moreover, most retrolaminar
blocks were predominantly associated with fascial spreading in the intrinsic back muscles. With an erector
spinae plane block, dye spread in a more lateral pattern than with retrolaminar block, and fascial spreading in
the back muscles was also observed. The number of stained thoracic spinal nerves was greater with erector
spinae plane blocks than with retrolaminar blocks; median 2.0 and 3.5, respectively. Regardless of technique,
the main route of dye spread was through the superior costotransverse ligament to the ipsilateral paravertebral
space. Although erector spinae plane blocks were associated with a slightly larger number of stained thoracic
spinal nerves than retrolaminar blocks, both techniques were consistently associated with posterior spread of
Anaesthesia 2018 doi:10.1111/anae.14408
Original Article
Comparison of injectate spread and ner
between retrolaminar and erector spina
the thoracic region: a cadaveric study
H.-M. Yang,1
Y. J. Choi,2
H.-J. Kwon,3
J. O,3
T. H. Cho3
and S. H
Anaesthesia 2018, 73, 1244–1250
“the amount of dye within the paravertebral space following both
retrolaminar and ESP injections seemed to be too small to allow for upward
or downward flow.”
@amit_pawa
50. Spread to Th PV Space in 4 out of 11 cadavers
(T2 injection)
Unpredictable Spread
Anesthesia & Analgesia. Publish Ahead of Print():, MAY 15, 2019 DOI: 10.1213/ANE.0000000000004187
ESP Mechanism?
@amit_pawa
51. ESP/MICB vs ThPVB
PV Spread in BOTH
MICB > ESP
2019 - Pub ahead of print
@amit_pawa
53. What can we say so far?
There is limited evidence of “By-Proxy” spread
Variation exists in Cadaver studies too!
Cadaver results may not relate to “Real Life”
(Mechanical Ventilation/Movement)
@amit_pawa
59. What do these say?
QL/ESP fascial plane blocks:
1. Reduce Pain Scores
2.Reduce Opioid Requirements
When compared to SYSTEMIC analgesia alone
@amit_pawa
63. Fascial Plane Blocks
Many unanswered questions
Unknown mechansims of action
Cadaveric studies do not reflect “real life”
Clinical studies demonstrate benefit - variable efficacy
Need more evidence
More Likely to be performed by the less experienced
@amit_pawa
64. Fascial Plane Blocks
Many unanswered questions
Unknown mechansims of action
Cadaveric studies do not reflect “real life”
Clinical studies demonstrate benefit - variable efficacy
Need more evidence
More Likely to be performed by the less experienced
Because, compared to TEA/PVB…
@amit_pawa
65. Fascial Plane Blocks
May be EASIER to site
May be SAFER to site - and may work “By Proxy”
May be QUICKER to site
SHOULD be combined with Multimodal Analgesics
Are HERE TO STAY!
@amit_pawa