Revisiting the Obturator Nerve Anatomy with a Nerve Blocking Perspective

Abstract

Abstract Purpose: Proper nerve blocking is significant for the success of locally anesthetized assisted surgeries. Dis-acknowledging the anatomical variations of targeted nerve anatomy can be problematic for the success of anesthetic fundamentals. Considering the diverse nature of obturator nerve (ON), blockage of ON (ONB) during clinical procedures can be counted within such problematic. Current focus is to revisit the ON anatomy via exemplifying at adult cadavers and fetuses, and then intensively discuss its relevance to ONB from an anatomical perspective. Methods: ON and its branches were exposed at the posterior wall of the abdomen, lateral wall of the lesser pelvis and anterior aspect of the thigh region in 47 fetuses and 10 adult cadavers. Thereafter, several anatomical motifs and morphometric of ON were meticulously assessed and measured. Results: Presence of anterior branches (AB) / posterior branches (PB) divergence in the obturator channel and extra-pelvic territory were detected as 40 and 60% respectively, while intra-pelvic occurrence wasn’t observed among the adult cadavers. In fetuses, regional distribution of ON divergence was scattered as 8.5% intra-pelvic, 33% in the channel and 58.5% distal to the channel. Concerning the muscular branching of ON, three fully traceable branching from AB and single one from PB were evident in all the adult cadavers. Significant morphometric distances were also provided in detail. Conclusion Our discussion regarding the variable motifs of ON anatomy from a nerve-blocking window, covering the results of the current and just few existed anatomical data sets might be helpful for anesthesiologists to improving the success of ONB.