An electrophysiologic evaluation of whether open and laparoscopic techniques used in pediatric inguinal hernia repairs affect the genitofemoral nerve

Abstract

Background: A prospective study was performed to evaluate the effect of inguinal hernia repairs on the genitofemoral nerve (GFN), and to compare postoperative electrophysiologic changes in the GFN of patients who had undergone either open or laparoscopic surgery.

Methods: Seventy patients with a mean age of 6.48 ± 3.49 were enrolled in the study. Either open or laparoscopic techniques were used to operate on the patients' inguinal hernias. In all cases, bilateral GFN motor responses were investigated electrophysiologically using surface electrodes on three occasions: preoperatively, in the first month, and third month postoperatively. t-Tests were used to compare changes in the GFN.

Results: Preoperative mean latency of the GFN in all groups was found to be significantly prolonged on the hernia side, compared with the non-hernia side (P = 0.01). Although no difference was observed in the latency levels of the GFN on the operated side at the preoperative and early postoperative stages, GFN latency levels decreased significantly in the late postoperative period in the laparoscopic group (P < 0.05). In the late postoperative period, amplitudes of GFN motor responses were significantly higher in the laparoscopic group than the open repair group (0.91 ± 0.11 mV and 0.57 ± 0.053 mV, respectively; P < 0.05).

Conclusion: Preoperative prolonged latency of GFN on the hernia side is likely to occur due to the pressure on the nerve caused by the hernia mass. By surgically removing the hernia mass, this buildup of pressure is prevented, decreasing the latency of the GFN. The significantly higher motor response amplitudes and decreased latency in the late postoperative stage for the laparoscopic group may be due to the fact that this technique is less invasive.

Keywords: Electrophysiology; Genitofemoral nerve; Inguinal hernia; Laparoscopy.