Effect of Intra-operative Autonomic Nerve Stimulation on Pelvic Nerve Preservation During Radical Laparoscopic Proctectomy

Aim: This study assessed the effect of intra-operative electrical nerve stimulation (INS) on pelvic autonomic nerve preservation (PANP) during laparoscopic resection for rectal cancer.

Method: A total of 189 consecutive cases of radical laparoscopic proctectomy were included. PANP was assessed visually or with INS. Urinary function was evaluated by residual urine volume (RUV), International Prostatic Symptom Score (IPSS) and recatheterization rate. Erectile function was evaluated using the International Index of Erectile Function (IIEF-5) scale.

Results: INS successfully confirmed PANP in 65 (91.5%) patients, while direct vision confirmed PANP in only 72 (61.0%) patients. Compared with the successfully confirmed patients, failed patients in the INS group exhibited higher postoperative RUV (100.0 ± 34.6 vs 25.2 ± 13.6 ml, P = 0.003), higher IPSS (7 days, 20.0 ± 8.6 vs 6.5 ± 2.4, P = 0.012; 1 month, 13.5 ± 6.0 vs 5.3 ± 1.9, P = 0.020; 6 months, 11.7 ± 5.1 vs 4.5 ± 1.7, P = 0.018), a greater number of incidences of a micturition disorder (66.7% vs 1.5%, P = 0.000), higher recatheterization rates (33.3% vs 1.5%, P = 0.017) and a lower IIEF score at 3 months (8.25 ± 0.96 vs 10.93 ± 1.99, P = 0.012) and 6 months (12.50 ± 1.29 vs 15.63 ± 1.65, P = 0.001) postoperatively. Compared with the vision group, the INS group had less deterioration in postoperative RUV (31.5 ± 26.4 vs 54.0 ± 46.7 ml, P = 0.000), lower IPSS (7 days, 7.7 ± 5.0 vs 11.0 ± 6.6, P = 0.000; 1 month, 6.0 ± 3.3 vs 7.6 ± 5.4, P = 0.012) and higher IIEF score (3 months, 10.69 ± 2.07 vs 9.42 ± 2.05, P = 0.001; 6 months, 15.36 ± 1.85 vs 13.64 ± 2.00, P = 0.000) as well as a lower incidence of urination disorders (7.0% vs 17.8%, P = 0.038).

Conclusion: INS is effective for the accurate evaluation of PANP during radical laparoscopic proctectomy. Combined with INS, laparoscopic proctectomy is more effective in urogenital function protection.