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Injectate spread following ultrasound‐guided lateral to medial approach for dual transversus abdominis plane blocks
Author(s) -
SONDEKOPPAM R. V.,
BROOKES J.,
MORRIS L.,
JOHNSON M.,
GANAPATHY S.
Publication year - 2015
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/aas.12459
Subject(s) - medicine , cadaver , anatomy , transversus abdominis , diaphragm (acoustics) , physics , acoustics , loudspeaker
Background Bilateral dual transversus abdominis plane ( BD ‐ TAP ) injections were devised to cover the T 7–8 and L 1 dermatomes, which are usually spared with classical and mid‐axillary TAP injections. The purpose of this study was to delineate the vertical and lateral extent of injectate spread following a lateral to medial approach for TAP injections in embalmed cadavers. Methods Ultrasound‐guided subcostal and lateral TAP injections were performed on nine embalmed cadavers using 30 ml of 0.5% methylcellulose (20 ml for subcostal and 10 ml for lateral injections) with a 12‐cm T uohy needle in the first six cadavers (nine hemi‐abdomens). Vertical extent and the medial to lateral extent of the dye spread were recorded after dissections of the abdominal wall. In a pilot of three cadavers not receiving TAP injections, anatomical impediments to proximal injectate spread were explored separately. Results The vertical spread of injectate was T 7– L 1 ( n = 2/9), T 8– L 1 ( n = 5/9) and T 9– L 1 ( n = 2/9). None of the TAP injections extended beyond the mid‐axillary line. No anatomical impediments for the flow of injectate to the T 7 or T 8 intercostal nerves were found at the level of the interdigitations of the transversus abdominis muscle and diaphragm. Conclusion A lateral to medial approach for TAP injection resulted in spread of the injectate ranging from T 7/8– L 1 dermatomes in the majority of the hemi‐abdomens. Subcostal and lateral TAP injections do not cover the lateral cutaneous branches of the segmental nerves.