Genitofemoral nerve course and branching variations: what we see during laparoscopic extended pelvic lymph-node dissection in radical prostatectomy for prostate cancer, and how to avoid intraoperative lesions: a retrospective analysis

摘要

BACKGROUND: The genitofemoral nerve is the most variable nerve of the lumbar plexus in terms of its course and bifurcation, and therefore it must be taken into consideration during extended pelvic lymph node dissection. Its borders, during robotic, laparoscopic or open radical prostatectomy for intermediate or high-grade prostate cancer, have long been defined and must be respected; the genitofemoral nerve represents the extended pelvic lymph-node dissection lateral boundary, and the fact that it may vary from case to case puts its integrity at risk. MATERIALS AND METHODS: For the first time, we report genitofemoral nerve branching pattern data obtained from extended pelvic lymph node dissection during videolaparoscopic radical prostatectomy. We also propose a further sub-classification to identify the exact genitofemoral nerve bifurcation point in correlation with the injury risk. RESULTS: Our results show the prevalence of a genitofemoral nerve originating as a single trunk which divides into two branches, and highlight how this condition occurs at the external iliac artery upper third in more than 75% of cases. Furthermore, at the femoral canal inlet, the genitofemoral nerve two branches were mainly seen lying laterally and below the external iliac artery, or in the middle of the external iliac artery and external iliac vein. CONCLUSIONS: Better understanding of the genitofemoral nerve course and bifurcation points deduced from the extended pelvic lymph node dissection, which are, in any case, applicable to all major pelvic surgery, would prove helpful in avoiding iatrogenic nerve injuries during extended pelvic lymph node dissection.