Significance of prostate weight on peri and postoperative outcomes of robot assisted laparoscopic extraperitoneal radical prostatectomy.

INTRODUCTION

To determine the significance of prostate weight (PW) on clinical and pathological outcomes in patients undergoing da Vinci robot assisted laparoscopic extraperitoneal radical prostatectomy (EP-RARP).

METHODS

From November 2008 to January 2010, 295 men underwent EP-RARP at our institution. We retrospectively reviewed our database and stratified patients into four groups based on pathologic PW: Group 1, less than 30 g; Group 2, 30 g to less than 50 g; Group 3, 50 g to less than 80 g; and Group 4, 80 g or larger. We prospectively compared these groups with respect to patient age, body mass index, prostate-specific antigen, Gleason score, pathological stage, margin status, operative time, blood loss, transfusion rate and length of stay. Statistical analysis was performed using SYSTAT 13 software. An analysis of variance (ANOVA) model was used to compare the continuous variables among the groups. Chi-square and Fisher's exact tests were used to compare categorical variables.

RESULTS

Of the 295 patients, 10, 182, 91, and 12 had a PW of less than 30 g; 30 g to less than 50 g; 50 g to less than 80 g; and 80 g or larger, respectively. A significant difference was found in age, prostate weight and prostate-specific antigen values among the four groups (p < 0.05). Patients in Group 4 had larger prostates, were older (mean age 65 years), had higher pretreatment prostate-specific antigen (median 5.85 ng/mL) and lower Gleason score (mean 6.2). Based on the D'Amico risk stratification, our study showed a trend toward higher risk disease, presence of extra capsular extension, seminal vesicle invasion and positive margin status in Groups 1, 2 and 3 rather than in Group 4. No significant differences in operative time, estimated blood loss, transfusion rate, hospital stay, and postoperative complication rate were observed among the four groups.

CONCLUSIONS

Da Vinci robot assisted laparoscopic extraperitoneal radical prostatectomy (EP-RARP) is feasible in patients with larger prostates, offering acceptable operative times, blood loss, hospital stay and complication rates. In our cohort of patients, we found pathologically smaller prostates are generally associated with higher Gleason score, higher risk group stratification and positive surgical margin status. Although technically challenging, increased prostate weight should not be considered a contraindication for EP-RARP if performed by experienced surgeons.