Does prostate weight affect perioperative outcomes, positive surgical margin rates and functional outcomes after robot-assisted radical prostatectomy performed by an experienced surgeon?

Aim: To determine whether prostate weight has an impact on pathological, perioperative and early functional outcomes after robot-assisted laparoscopic radical prostatectomy (RARP). Patients and Methods:We analyzed 1,831 consecutive patients who underwent RARP by a single surgeon. Patients were stratified into three groups on the basis of pathological prostate weight: group 1: <30 g, group 2: 30 to 49.9 g, group 3: 50 to 69.9 g and group 4: >70 g. Continence was defined as the use of ‘no pads’. Potency was defined as the ability to achieve and maintain adequate erections for penetration more than 50% of the time with or without the use of PDE-5 inhibitors. Only patients with preoperative SHIM score >21 and who underwent bilateral nerve-sparing procedure were included in the study. Groups were compared using one-way ANOVA on ranks test and the Dunn’s method for multiple comparisons when statistically significant differences were found. Results: Patients with a larger prostate (group 4) were older (median age 65 years), had higher pre-treatment PSA (median 5.8 ng/ml), higher AUA-SS (median 9), longer operative time (median 80 min) and higher estimated blood loss (median 100 cc) (p<0.001 for all variables). There was no association between prostate size and body mass index, biopsy Gleason score, clinical stage, catheterization time, pathological stage, hospital stay, anastomotic leak rates, specimen Gleason score and continence rates (at one, three and six months). Overall positive surgical margin rates were lower in patients with prostate size larger than 70 g when compared to the other groups (14.4% vs. 12.5% vs. 10.2% vs. 7.2%, respectively, p<0.001). There was a trend towards lower potency rates in patients with prostates larger than 70 g at four weeks (45.4% vs. 35% vs. 32% vs. 25%, p=0.065) and three months (72% vs. 75% vs. 75.2% vs. 65%, p=0.07) after RARP, although the potency rates were similar among the groups at six months after surgery. Conclusion: RARP performed by an experienced surgeon in patients with an enlarged prostate is feasible, with slightly higher operative time and estimated blood loss and without any impact on early continence rates. There was a trend towards lower early potency rates in patients with larger prostates, which can probably be explained by the greater age of these patients. Pathologically larger prostates were associated with lower overall PSM rates even though the pathological stage and specimen Gleason score were similar in the groups.