The addition of robotic assistance with the da Vinci surgical system for performing laparoscopic radical prostatectomy has been reported to improve surgical outcomes. In order to evaluate the benefit of robotic assistance to improve cancer control in a center with an established laparoscopic radical prostatectomy program, we evaluated the incidence of positive surgical margins in both transperitoneal laparoscopic (LRP) and robotically assisted laparoscopic radical prostatectomy (RALP).
We performed an Institutional Review Board (IRB) approved, retrospective review of 247 men with clinically localized prostate cancer treated with either a LRP or a RALP from March 2000 to August 2006. Pathology reports were reviewed for both preoperative and postoperative Gleason score as well as clinical and pathological stage. Surgical pathology specimens were evaluated using a whole mount, step section technique. Extracapsular extension, seminal vesicle invasion and positive margins were noted when present in the final surgical pathologic specimens.
One hundred ninety seven patients underwent LRP, and 50 patients underwent RALP. Seven of the 197 LRP required open conversion to retropubic radical prostatectomy, and were excluded. None of the RALP were converted. The overall positive surgical margin rate for LRP and RALP was 18% (35/190) and 6% (3/50), respectively (p = 0.032). When examining pathologically organ confined specimens (pT2), the positive surgical margin rate was 12% (20/161) and 4.7% (2/43) for the LRP and RALP cohorts, respectively (p = 0.181). For pathologic disease that has spread outside the capsule (pT3/T4), the positive surgical margin rate was 54% (15/28) and 14% (1/7) for LRP and RALP, respectively (p = 0.062). Patient age, race and prostate volume were not significant factors in the incidence of positive surgical margins.
The addition of robotic assistance to an established laparoscopic radical prostatectomy program appears to reduce the incidence of positive surgical margins. Data is maturing to determine whether this will lead to improved functional and oncologic outcomes.