Impact of Prostate Volume on Oncological and Functional Outcomes After Radical Prostatectomy: Robot-Assisted Laparoscopic Versus Open Retropubic

Purpose: We compared the impact of prostate volume on oncological and functional outcomes 2 years after robot-assisted laparoscopic prostatectomy (RALP) and open radical retropubic prostatectomy (ORP). Materials and Methods: Between 2003 and 2010, 253 consecutive patients who had undergone prostatectomy by a single surgeon were serially followed over 2 years postoperatively. RALP was performed on 77 patients and ORP on 176. The patients were divided into two subgroups according to prostate volume as measured by transrectal ultrasound: less than 40 g and 40 g or larger. Recoveries of potency and continence were checked serially by interview 1, 3, 6, 9, 12, and 24 months postoperatively. Results: RALP was associated with less blood loss (ORP vs. RALP: 910 mL vs. 640 mL, p< 0.001) but a longer operation time (150 minutes vs. 220 minutes, p< 0.001) than was ORP. No statistically significant differences were found between the two groups for oncological outcomes, such as positive surgical margin (40% vs. 39%, p=0.911) or biochemical recurrence (12% vs. 7%, p=0.155). The overall functional outcomes showed no statistically significant differences at 2 years of follow-up (continence: 97% vs. 94%, p=0.103; potency: 51% vs. 56%, p=0.614). In the results of an inter-subgroup analysis, potency recovery was more rapid in patients who underwent RALP in a small-volume prostate than in those who underwent ORP in a small-volume prostate (3 months: 24% vs. 0%, p=0.005; 6 months: 36% vs. 10%, p=0.024). However, patients who underwent RALP in a large-volume prostate were less likely to recover continence than were patients who underwent ORP in a large-volume prostate (97% vs. 88%, p=0.025). Conclusions: Patients can be expected to recover erectile function more quickly after RALP than after ORP, especially in cases of a small prostate volume.