Incidence and location of positive surgical margin among open, laparoscopic and robot-assisted radical prostatectomy in prostate cancer patients: a single institutional analysis

To evaluate the positive surgical margin rates and locations in radical prostatectomy among three surgical approaches, including open radical prostatectomy, laparoscopic radical prostatectomy and robot-assisted radical prostatectomy.We retrospectively reviewed clinical outcomes at our institution of 450 patients who received radical prostatectomy. Multiple surgeons were involved in the three approaches, and a single pathologist conducted the histopathological diagnoses. Positive surgical margin rates and locations among the three approaches were statistically assessed, and the risk factors of positive surgical margin were analyzed.This study included 127, 136 and 187 patients in the open radical prostatectomy, laparoscopic radical prostatectomy and robot-assisted radical prostatectomy groups, respectively. The positive surgical margin rates were 27.6% (open radical prostatectomy), 18.4% (laparoscopic radical prostatectomy) and 13.4% (robot-assisted radical prostatectomy). In propensity score-matched analyses, the positive surgical margin rate in the robot-assisted radical prostatectomy was significantly lower than that in the open radical prostatectomy, whereas there was no significant difference in the positive surgical margin rates between robot-assisted radical prostatectomy and laparoscopic radical prostatectomy. In the multivariable analysis, PSA level at diagnosis and surgical approach (open radical prostatectomy vs robot-assisted radical prostatectomy) were independent risk factors for positive surgical margin. The apex was the most common location of positive surgical margin in the open radical prostatectomy and laparoscopic radical prostatectomy groups, whereas the bladder neck was the most common location in the robot-assisted radical prostatectomy group. The significant difference of positive surgical margin locations continued after the propensity score adjustment.Robot-assisted radical prostatectomy may potentially achieve the lowest positive surgical margin rate among three surgical approaches. The bladder neck was the most common location of positive surgical margin in robot-assisted radical prostatectomy and apex in open radical prostatectomy and laparoscopic radical prostatectomy. Although robot-assisted radical prostatectomy may contribute to the reduction of positive surgical margin, dissection of the bladder neck requires careful attention to avoid positive surgical margins.