To investigate the impact of variations in bony pelvic dimensions observed from preoperative magnetic resonance imaging on operative time, intraoperative blood loss, and surgical margin status on performing open radical retropubic prostatectomy.

A prospective study was undertaken in which preoperative magnetic resonance imaging was performed in 190 patients who were diagnosed with clinically localized prostate cancer before radical retropubic prostatectomy. Using the magnetic resonance image findings, various bony pelvic dimensions were measured. The associations of the measured pelvic dimensions and various clinicopathologic factors with the operative time, estimated blood loss, and surgical margin status were analyzed on multivariate analyses.

For operative time, none of the individual pelvic dimensions measured demonstrated significant associations on univariate analysis. In contrast, only the newly developed parameter, the pelvic dimension index, approached significance (P = 0.095). Only body mass index (BMI) proved to be independently associated with the operative time on multivariate analysis (P = 0.030). Also, only the prostate volume (P = 0.015) was independently associated with the estimated blood loss. For the surgical margin status, the preoperative PSA level (P = 0.041), pathologic Gleason score (P = 0.015), and BMI (P = 0.020), along with the pelvic dimension index (P = 0.048), demonstrated significant associations on univariate analyses. However, only the PSA level (P = 0.071) and BMI (P = 0.059) approached significance on multivariate analysis.

Our results have demonstrated that variations in the bony pelvic dimensions might have some impact, but not significantly so, on open radical retropubic prostatectomy compared with other patient-related baseline factors such as the BMI or prostate volume.