Comparison between two approaches for the transversus abdominis plane block in canine cadavers

Ultrasound-Guided Lateral Transversus Abdominis Plane (TAP) Block in Rabbits: A Cadaveric Study

“…This suggests that, despite the high volume used, in a clinical context, a single injection of local anaesthetic would not be able to adequately cover all abdominal sensory branches in the TAP. Moreover, in agreement with the results of Zoff et al and Romano et al [16,23], we found a significant dorsoventral diffusion (44.48 ± 9.26 mm). This showed that the use of large volumes probably does not improve the craniocaudal spread (48.91 ± 7.56 mm) but induces diffusion of local anaesthetic evenly over the entire abdominal wall.…”

“…The results obtained in this cadaveric study indicate that the TAP block performed with a single lateral injection can be easily performed in rabbits, but it is probably not sufficient to cover the nerve eminences of the cranial abdomen. Based on the results observed from this study and the findings from previous studies in other species [7,16], the two-point TAP block (lateral and subcostal) could represent a better option to provide adequate analgesia during abdominal surgery in this species, particularly when a large surgical incision is required. However, to evaluate the real analgesic efficacy, in vivo studies are necessary.…”

“…This showed that the use of large volumes probably does not improve the craniocaudal spread (48.91 ± 7.56 mm) but induces diffusion of local anaesthetic evenly over the entire abdominal wall. It is the authors' opinion that it could be useful in this species, as already demonstrated in the cat [7] and dog [16] cadavers, to use a two-point TAP block (subcostal and lateral) to obtain a better cranial distribution of the local anaesthetic and to reduce the total volume injected.…”

“…Compared to classic neuraxial techniques, fascial plane blocks are considered at low risk of nerve injury and relatively easy to perform; however, it should be emphasised that the TAP block only provides somatic analgesia (from the ventrolateral skin of the abdomen to the peritoneum); therefore, during surgery involving visceral pain, systemic drugs are needed to achieve adequate analgesia [15,23]. Either way, according to the current literature in human and veterinary medicine, the TAP block has been demonstrated to produce great results as part of a multimodal approach in the management of perioperative abdominal pain [15][16][17]24]. Some limitations need to be considered in this study.…”

“…The lateral approach is performed by positioning the US probe in a transverse orientation midway between the iliac crest and the caudal aspect of the rib cage, lateral to the midline of the abdomen [10], and the subcostal oblique approach is performed with cadavers positioned in dorsal recumbency, placing the probe caudally to the xiphoid process, parallel to the costal arch and oblique to the midline [14]. Alternative approaches with two sites of injection, one caudal to the last rib and the other cranial to the iliac crest, have been used to provide successful analgesia in dogs [12][13][14][15][16]. The spread of the volume injected and the features of these two different approaches were evaluated in dog [14,17,18], cat [7], pony [11], and calf [6] cadavers, as well as in one Canadian lynx [4], cats [19], ponies [9], and dogs [12] in vivo studies.…”