Retroperitoneal course of iliohypogastric, ilioinguinal, and genitofemoral nerves: A study to improve identification and excision during triple neurectomy.

Triple neurectomy of the iliohypogastric (IHN), ilioinguinal (IIN), and genitofemoral (GFN) nerves is an available treatment option for chronic groin pain when conservative measures are ineffective. This research study attempted to define the variability of IHN, IIN, and GFN by categorizing variation and establishing a relationship to clinically significant landmarks. 22 cadavers (43 specimens) were dissected. Age, gender, ethnicity, BMI, and pertinent medical history were recorded for each specimen. Nerve emergence, insertion, and split points were measured in relation to clinically significant landmarks. Retroperitoneal trajectories of IHN, IIN, and GFN were analyzed and categorized based on nerve branching patterns. IIN and IHN had three branching patterns - type A (47%) in which the IIH and IIN exit as separate branches; type B (26%) in which the IIH and IIN exit as a single bundle and split; and type C (28%) in which the IIH and IIN exit and do not split. The GFN had three branching patterns--type 1 (50%) in which the GFN exited from the psoas major and then split into the genital and femoral branches; type 2 (30%) in which the GFN exited and did not split; and type 3 (20%) in which the GFN exited the psoas major already split into the genital and femoral branches. Variations in the IHN, IIN, and GFN nerves outlined in this study will provide surgeons with clinically useful information aiding in successful and efficient localization of these nerves during retroperitoneal procedures, including laparoscopic triple neurectomy.