Evaluating Patterns of Injectate Spread After Rectus Sheath Block: A Cadaveric Dissection Study

Abstract

Introduction: This cadaveric dye study assesses the effect of volume and number of injections on the spread of solution after ultrasound-guided rectus sheath injections. In addition, this study evaluates the impact of the arcuate line on solution spread.Materials and methods: Ultrasound-guided rectus sheath injections were performed on seven cadavers on both sides of the abdomen, for a total of 14 injections. Three cadavers received one injection of 30 mL of a solution consisting of bupivacaine and methylene blue at the level of the umbilicus. Four cadavers received two injections of 15 mL of the same solution, one midway between the xiphoid process and umbilicus and one midway between the umbilicus and pubis.Results: Six cadavers were successfully dissected and analyzed for a total of 12 injections, while one cadaver was excluded due to poor tissue quality that was inadequate for dissection and analysis. There was a significant spread of solution with all injections caudally to the pubis without limitation by the arcuate line. However, a single 30 mL injection showed inconsistent spread to the subcostal margin in four of six injections, including in a cadaver with an ostomy. A double injection of 15 mL showed consistent spread from xiphoid to pubis in five of six injections, except in a cadaver with a hernia.Conclusions: Injections deep to the rectus abdominis muscle, using the same technique as an ultrasoundguided rectus sheath block, achieve spread along a large and continuous fascial plane without limitation by the arcuate line and may provide coverage of the entire anterior abdomen. A large volume is necessary for complete coverage and spread is improved with multiple injections. We suggest that two injections with a total volume of at least 30 mL per side may be needed to achieve adequate coverage in the absence of preexisting abdominal abnormalities.

Liposomal bupivacaine for ultrasound‐guided rectus sheath blocks after midline laparotomy

“…A study describing the spread and effectiveness of levobupivacaine 0.375% used 20 ml of local anaesthetic for umbilical hernia repair surgery [ 9 ]. A recent study of seven cadavers suggests that at least 30 ml per side is needed for spread from xiphoid to pubis [ 10 ].…”

The Spread Distance of Local Anesthetics in the Rectus Sheath Block in Children Aged 0-8 Years: A Retrospective Study

“…On the other hand, as we directly measured the spread distance of a volume of 0.5 mL/kg of LA, the data in our study may contribute to the current literature to help decide whether one or two injection points are required to cover the entire surgical incision according to its length. A similar suggestion of deciding the need for two injection points for the RSB to cover the surgical incision, based on the knowledge of the spread distance that can be obtained with a single injection, was made by Rojas et al in their cadaver study [ 2 ].…”

“…In addition to determining the LA volume, the injection point and number of injections required were studied. Knowing the spread distance that can be achieved with a single injection could guide in deciding whether more than one injection is required to cover the entire surgical incision [ 2 ]. Our experience on RSB grew with the evaluation of the spread distance of LA within a total length of the abdominal wall in mid-line from xiphoid to pubis.…”

“…The spread of the local anesthetic (LA) solution in the rectus sheath should cover the entire surgical incision to achieve the optimal effect of the RSB [1]. The factors affecting this spread have been addressed in previous studies including both anatomical and clinical studies [1][2][3][4][5][6]. The anatomical studies included animal cadavers and adult human cadavers, whereas the clinical studies mostly included adult patients [1,[2][3][4]7,8].…”

“…The factors affecting this spread have been addressed in previous studies including both anatomical and clinical studies [1][2][3][4][5][6]. The anatomical studies included animal cadavers and adult human cadavers, whereas the clinical studies mostly included adult patients [1,[2][3][4]7,8]. The limited clinical studies on the effect of RSB in children included pediatric patients of a large age range, leading to a heterogeneous group in terms of anthropometric measures [1,5,9,[10][11][12].…”