title: Development of an ultrasound-guided technique for pudendal nerve block in cat cadavers.
abstract: The objective of this prospective experimental cadaveric study was to develop an ultrasound-guided technique to perform an anaesthetic pudendal nerve block in male cats. Fifteen fresh cadavers were used for this trial. A detailed anatomical dissection was performed on one cat in order to scrutinise the pudendal nerve and its ramifications. In a second step, the cadavers of six cats were used to test three different ultrasonographic approaches to the pudendal nerve: the deep dorso-lateral, the superficial dorso-lateral and the median transperineal. Although none of the approaches allowed direct ultrasonographical identification of the pudendal nerve branches, the deep dorso-lateral was found to be the most advantageous one in terms of practicability and ability to identify useful and reliable landmarks. Based on these findings, the deep dorso-lateral approach was selected as technique of choice for tracer injections (0.1 ml 1% methylene blue injected bilaterally) in six cat cadavers distinct from those used for the ultrasonographical study. Anatomical dissection revealed a homogeneous spread of the tracer around the pudendal nerve sensory branches in all six cadavers. Finally, computed tomography was performed in two additional cadavers after injection of 0.3 ml/kg (0.15 ml/kg per each injection sites, left and right) contrast medium through the deep dorso-lateral approach in order to obtain a model of volume distribution applicable to local anaesthetics. Our findings in cat cadavers indicate that ultrasound-guided pudendal nerve block is feasible and could be proposed to provide peri-operative analgesia in clinical patients undergoing perineal urethrostomy.
authors.affiliation: 1Department of Veterinary Clinical Science, Anesthesiology and Pain Therapy Division, Vetsuisse Faculty, University of Berne, Berne, Switzerland.
authors.forename: Chiara
authors.initials: C
authors.lastname: Adami
authors.forename: Giovanni
authors.initials: G
authors.lastname: Angeli
authors.forename: Kati
authors.initials: K
authors.lastname: Haenssgen
authors.forename: Michael H
authors.initials: MH
authors.lastname: Stoffel
authors.forename: Claudia
authors.initials: C
authors.lastname: Spadavecchia
mesh_terms: D000818:Animals; D002102:Cadaver; D002415:Cats / Q000033:anatomy & histology*; D008297:Male; D008751:Methylene Blue; D009407:Nerve Block / Q000379:methods / Q000662:veterinary*; D060525:Pudendal Nerve / Q000187:drug effects*; D014465:Ultrasonics / Q000379:methods*
chemical_list: D008751:Methylene Blue