Clinical application of different bladder neck separation techniques in robot-assisted laparoscopic radical prostatectomy

Objective To investigate the clinical effect of different bladder neck separation methods in robot-assisted laparoscopic radical prostatectomy (RARP). Methods To retrospective analysis the data of robot-assisted laparoscopic radical prostatectomy (RARP)in our center from October, 2014 to October, 2018. All operations were performed by the same urologist. According to the different methods of bladder neck separationAccording to the different methods of bladder neck separation, all the patients were divided into four groups. Group A routine forward peeling method (500 cases): Make a 1cm incision at 12 o'clock on the front of the bladder neck, cut off the detrusor muscle and cut the bladder neck. Group B T-cut incision of the bladder neck (133 cases): identify the bladder and prostate Junction, T-shaped incision of the anterior wall of the bladder neck. Group C conventional stripping method combined with T-shaped incision of the bladder neck (81 cases). Group D lateral approach (36 cases): along the lateral side of the bladder neck and the medial posterior ligament of the prostate is separated and merges with the previously established Dirichlet space. The general data of patients were analyzed statistically.The average ages of groups A, B, C, and D were 63 years (62.5 to 67 years), 65 years (61 to 68 years), 66 years (64.5 to 70.5 years), and 62 years (59.5 to 66.5 years)respectively, there was no statistical significance difference in terms of age in 4 groups(P>0.05); PSA is 13 ng/ml(9.0 to 22 ng/ml), 7.4 ng/ml(6.4 to 26.0 ng/ml), 6.2 ng/ml(5.3 to 27.0 ng/ml), 14ng/ml(8.4 to 21.0 ng/ml), (P>0.05); Gleason scores of puncture were 6.9(5 to 9), 7(6 to 12), 9(8 to 16), 10(6 to 18), (P>0.05); the prostate volume was 66ml(42 to 78 ml), 70ml(50 to 89 ml), 53ml (43 to 72 ml), 80 ml (68 to 92 ml), (P>0.05); the proportions of body mass index ≤25 kg/m2 were 60.0%, 63.9%, 39.1%, 42.0%, and>25 kg/m2 were 40%, 36.1%, 60.9%, and 58.0%, respectively, (P>0.05). The operation time, bleeding volume, anastomosis time, postoperative hospital stay, postoperative complications, positive rate of proximal incision margin, urinary indwelling time, and urinary control rate in the four groups analyzed. Results All 750 RARP operations were successful, and none were converted to open.The operation time of groups A, B, C, and D were 100 min(70 to 120 min), 89 min(70 to 95 min), 105 min(80 to 127 min), and 110 min(90 to 130 min), (P>0.05); anastomosis time was 20.5 min (18.0 to 25.0 min)、16.1min (10.7 to 17.3 min)、25.4 min (18.9 to 27.0 min)、and 28.5 min (21.0 to 32.0 min), the anastomosis time in group B was significantly shorter than other groups (P 0.05). Postoperative complications: Anastomotic fistula and ureteral injury occurred in 3 cases in group A, and no serious complications occurred in the other 3 groups. Proximal marginal positive rate: 40 cases (8.0%) in group A, 0 cases in group B, 6 cases (7.3%) in group C, 3 cases (8.3%) in group D, and low positive rate of margin incision in group B(P 0.05). Six-month postoperative urine control rate: 381 cases (75.2%) in group A, 102 cases (76.9%) in group B, 61 (75.4%) in group C, and 27 (73.8%) in group D, (P>0.05). Conclusions The above four method of bladder neck separation during robot-assisted laparoscopic radical prostatectomy is safe and feasible, which can effectively avoid ureteral damage. Each method can obtain better urine control within six months after surgery rate. The positive rate of proximal incision margin after T-shaped bladder neck was lowest among four groups. Key words: Prostatic neoplasms; Robotic surgery system; Bladder neck separation