Bloqueo ecoguiado del nervio obturador al nivel de la rama púbica superior: estudio en cadáver embalsamado en Thiel utilizando látex

Abstract

Introduction

A proximal obturator nerve block has a similar block efficacy as the distal obturator nerve block. Previous cadaveric investigation injecting methylene blue dye solution and an immediate dissection proved the solution engulfing the anterior and posterior divisions of the obturator nerve as they emerge from the obturator canal. Uptake of methylene blue dye by the fascia and muscles obscures the exact delineation of the stained nerves. We hypothesized that injection of latex at the level of superior pubic rami in the plane between pectineus and obturator externus under real time ultrasound and a delayed dissection in a Thiel-based cadaver would be the optimal cadaveric investigational technique.

Methods

Three investigated bodies donated to science (BDTS) fall under the strict rules of the donation program of the Department of Macroscopic and Clinical Anatomy of the Medical University of Graz and the Styrian burial law. The BDTS were embalmed with Thieĺs method which provides very lifelike conditions for investigations with regional anaesthesia backgrounds. In two cadavers (a total of specimens), latex injections were performed under ultrasound, while in the third cadaver cross-sections were executed.

Results

Our Thiel based cadaveric open dissection (C1 and C2) demonstrated that a single injection of latex in the inter-fascial plane between the pectineus muscle and the obturator externus muscle at the level of superior pubic ramus led to adequate spread along trunk of the obturator nerve and its branches in all specimens.

Conclusions

An in-plane ultrasound-guided latex injections at the level of superior pubic rami, between the pectineus and the obturator externus muscles soaks the anterior ramus, posterior ramus, and the obturator nerve trunk.