Influence of identification and preservation of pelvic autonomic nerves in rectal cancer surgery on bladder dysfunction after total mesorectal excision

PURPOSE: Given the improvement in oncologic outcome after the introduction of total mesorectal excision for the treatment of rectal cancer, the objective of the present study was to determine the frequency of identification and preservation of the pelvic autonomic nerves and to identify a possible link between postoperative micturition disturbances and the extent of the radical resection. METHODS: Between March 1997 and December 2001, 150 patients with adenocarcinoma of the rectum (≤16 cm from the anal verge) underwent surgery, with sphincter preservation in 112 cases (74.7 percent). Sixty-three patients (42 percent) were classified as American Society of Anesthesiologists Stage III and two (1.3 percent) as Stage IV. The number of cases with complete identification, partial identification, or nonidentification of the autonomic nerves (superior hypogastric plexus, hypogastric nerve, and inferior hypogastric plexus) was documented and correlated with micturition disturbances (need for a long-term urinary catheter). Urine volumes were measured by ultrasound before and after surgery. RESULTS: The pelvic autonomic nerves were identified completely in 108 patients (72 percent), partially in 16 (10.7 percent), and not at all in 26 (17.3 percent). After the initial phase of the study (n = 50 patients), complete identification was realized in 78 percent of cases. Multivariate analysis showed that of the predetermined parameters (learning curve for Group I vs. Groups II or III, gender, T stage, blood loss, curative surgery, and previous surgery), gender (P = 0.006), learning curve (P = 0.019), and depth of penetration of the rectal wall (T1/T2 vs. T3/T4; P = 0.028) exerted an independent influence on achievement of complete pelvic nerve identification. Sixteen patients (10.7 percent) were discharged from the hospital with a urinary catheter. Identification and preservation of the pelvic autonomic nerves was associated with low bladder dysfunction rates (4.5 vs. 38.5 percent; P < 0.001). In the evaluation of preoperative and postoperative bladder function, a urologic history and residual urine volume measurements by ultrasound were essential. The information obtained from urodynamic studies was of no relevance. CONCLUSIONS: Identification and preservation of the pelvic autonomic nerves was achieved in the majority of patients and led to the prevention of urinary dysfunction. Gender (P = 0.006), learning curve (P = 0.019), and T stage are independent parameters that influence outcome.