Anatomic study of the lateral femoral cutaneous nerve with respect to the ilioinguinal surgical dissection

Objective: To report on the anatomic variations of the lateral femoral cuta neous nerve with respect to the ilioinguinal surgical dissection. Design: Cadaveric anatomic study. Patients/Participants: Sixty-eight ilioinguinal dissections performed in fi fty cadavers. Intervention: The lateral femoral cutaneous nerve was identif ied, and certain location variables were recorded. Main Outcome Measure: The distance in millimeters from the medial edge of t he anterior superior iliac spine (ASIS), whether the nerve was lateral or m edial to the ASIS, and the layer in which the nerve crossed the dissection. Results: In seven dissections, the nerve was twenty-one to twenty-five mill imeters medial to the ASIS; in ten dissections, the nerve was twenty-six to thirty millimeters from the ASIS; and in fourteen dissections, the nerve w as more than thirty millimeters medial to the superior border of the ASIS. The average medial distance from the ASIS was 20.4 millimeters, with a rang e of three to forty-six millimeters. In no specimen did the nerve pass late ral to the ASIS. The lateral femoral cutaneous nerve was found to lie anter ior to the iliopsoas muscle in all specimens. Conclusion: The course of the lateral femoral cutaneous nerve is highly var iable; the nerve was most commonly found at ten to fifteen millimeters from the ASIS and as far medially as forty-six millimeters. When using the illi oinguinal surgical approach, if the lateral femoral cutaneous nerve is not encountered immediately adjacent to the ASIS, dissection up to five centime ters medial to the ASIS may be necessary to locate the nerve.