Description of different ultrasound guided transversus abdominis plane block in pig cadavers – A pilot study. (May 2021)

• Record Type: Journal Article
• Authors: Michielsen, Anneleen J.H.C.; Rodrigo-Mocholí, Diego; Cornillie, Pieter; Gasthuys, Frank; Schauvliege, Stijn
• Is Part Of: Veterinary anaesthesia and analgesia. Volume 48:Number 3(2021)
• Page Start: 470
• Page End: 477
• Publication Date: 2021-05
• Subjects: analgesia -- nerve staining -- pigs -- regional anaesthesia -- TAP block -- ultrasound; Veterinary anesthesia -- Periodicals; 636.089
• DOI: 10.1016/j.vaa.2020.10.012
• Languages: English
• ISSNs: 1467-2987

Abstract

Abstract: Objective: To develop an ultrasound (US)-guided transversus abdominis plane (TAP) block in pigs. Study design: Prospective, descriptive, experimental study. Animals: A total of 26 hemi-abdomens belonging to 13 Seghers Hybrid cadavers. Methods: The study consisted of two parts. In part 1, a preliminary anatomical understanding of the abdominal wall innervation in pigs was established (two hemi-abdomens of one pig). Part 2 was divided into three phases, and a US-guided TAP technique using methylene blue dye (0.3 mL kg –1 for each hemi-abdomen) was developed. In chronological order, a pilot study (phase I) was conducted to establish good injection points (four hemi-abdomens). In phase II a two-point injection technique (10 hemi-abdomens) was performed. A cranial injection was made at two-thirds of the distance between the xyphoid process and the iliac crest, immediately ventral to the rib arch. A caudal injection was performed ventral to the last rib. In phase III a three-point injection technique was performed (10 hemi-abdomens) with an extra injection point halfway between the cranial and caudal injection point. Staining of the different nerves was recorded during dissection. Results: In part 1 the nerves innervating the pig's abdominal wall, thoracic vertebrae 12–16 (T12–16) and lumbar vertebrae 1–3 (L1–3), were identified. In part 2, data from the pilot study, adequate nerve staining with the two- or three-point injection technique, were obtained in T12 (29 versus 45% respectively), T13 (29 versus 100%), T14 (73 versus 45%), T15 (75 versus 7 8%), T16 (58 versus 78%), L1 (100 versus 75%), L2 (88 versus 84%) and L3 (23 versus 0%). Conclusions and clinical relevance: US-guided TAP block can be used in swine but only a moderate success rate for adequate nerve staining was achieved in this study. Further studies are necessary to determine a correct injection volume and assess clinical intra- and postoperative efficacy.