To investigate the incidence of radical prostatectomy-related inguinal hernia (RPRIH) and the predictive factors for RPRIH.

We reviewed the medical charts of patients who had undergone retropubic radical prostatectomy (RRP) at our institution from January 2002 to December 2004 and had a median follow-up of 17 months (range 3 to 42). All patients were examined for RPRIH every 3 months. We also reviewed the computed tomography results in a blinded manner and investigated the predictive factors for RPRIH with multivariate analysis using the Cox proportional hazards model.

Of 98 patients analyzed, 17 were diagnosed with RPRIH after RRP (17.3%) at the median of 7 months (range 3 to 12). Preoperative computed tomography results were available for all patients, and subclinical inguinal hernia was identified in 20 (20.4%) of the 98 patients. Multivariate analysis showed that a subclinical inguinal hernia was the single predictive factor for RPRIH. The estimated rate of RPRIH was 60.6% in the subclinical inguinal hernia group and 9.5% in the normal group at 12 months (log-rank test, P <0.001).

The results of the present study have indicated that a preoperative computed tomography finding of a subclinical inguinal hernia predicts for postoperative inguinal hernia formation after RRP. RRP might only advance the time at which the inguinal hernia would develop with or without surgery. Thus, all patients with a subclinical inguinal hernia finding should be informed about the possibility of the development of RPRIH within 12 months after RRP and recommended to undergo surgical repair at RRP.