Effect of a large prostate gland on open and robotically assisted laparoscopic radical prostatectomy

To evaluate the outcomes based on gland size between robotically assisted radical prostatectomy (RALP) and open RP (RRP), as larger prostates might increase the difficulty of RP. We reviewed 660 patients who had RALP and 340 who had RRP from May 2003 to August 2006; the patients were divided into two groups, with a prostate of > 75 and <= 75 g. The clinical characteristics, surgical approach, perioperative and postoperative outcomes were evaluated. Patients with large prostates were significantly older (P < 0.001), but had a lower pathological stage (RALP, P = 0.046, and RRP, P = 0.008) than patients with small glands, regardless of technique. There was no difference in length of stay or transfusion rates between the groups. A large prostate increased the operative duration of RALP (P < 0.001) but not of RRP. For both RALP and RRP, positive margin rates were lower with larger glands (RALP, P = 0.014; RRP, P = 0.033). Overall, the positive margin rates were lower with RALP (9.9% and 19.0%) than RRP (18.5% and 35.5%) among patients with larger or smaller (P < 0.001) glands, respectively. Prostates of >= 75 g had fewer positive margins than smaller glands, regardless of surgical technique. There was also a significant decrease in positive margin rate in among prostates of > 75 g in favour of RALP. Thus, RALP appears to be comparable with RRP for patients with large glands, and might reduce the positive margin rate.