[Anti-cicatricial and anti-restenosis effect of verapamil on anterior urethral stricture: A randomized controlled clinical trial].

To evaluate the anti-cicatricial and anti-restenosis effect of verapamil on anterior urethral stricture.

Methods

A total of 32 patients received anterior urethral stricture were enrolled in this study. They were divided into 4 blocks according to the duration of previous urethral operations and dilations. Every block was further randomly divided into an experimental group and a control group. Experimental groups received 2 mL injection of verapamil around the anastomosis site of urethra before and after the surgery (2, 4, 6, 8, and 10 weeks after the surgery), while the control groups only received the anastomosis surgery. After surgery, maximal urinary flow rate (Qmax) was examined for all patients once the catheter was removed. In addition, they were also conducted palpation of urethral scar range. The sum of long transverse diameters of urethral scar was measured, and the narrowest urethral inner diameter was examined. The Qmax was rechecked and the urethral scar range was assessed by penis color Doppler elastography after 12 weeks of surgery. The above 4 indexes were used to evaluate the inhibitory effect of verapamil on urethral scar.

Results

The length of palpated urethral scar in the Block 1 to 4 of the experimental groups was (22.75±1.03), (21.25±0.25), (20.75±1.03), and (20.0±0.58) mm, respectively; and those in the control groups (26.00±0.82), (24.5±1.04), (25.75±1.65), and (28.25±1.75) mm, respectively. The Qmax rates in the Block 1 to 4 of the experimental groups were (11.85±0.77), (11.33±0.81), (10.23±0.26), and (10.35±0.17) mL/s, respectively; and those in the control groups were (10.85±0.39), (10.50±0.76), (10.53±1.00), (12.60±0.39) mL/s, respectively. The Qmax rates in the Block 1 to 4 of the experimental groups were (11.73±0.87), (10.65±0.25), (10.23±0.19), and (10.35±0.29) mL/s, respectively; and those in the control groups were (8.05±0.28), (7.73±0.68), (7.53±0.92), and (9.60±0.32) mL/s, respectively. The narrowest diameters of urethral in the Block 1 to 4 of the experimental groups were (9.00±0.58), (7.50±2.89), (7.00±0.10), and (7.00±0.41) mm, respectively; and those in the control groups were (5.50±0.29), (5.00±0.41), (4.75±0.48), and (6.75±0.48) mm, respectively. The ultrasound strain ratio in the Block 1 to 4 of the experimental groups were 6.10±0.22, 6.10±0.17, 5.10±0.16, and 6.90±0.19, respectively; and those in the control groups were 8.00±0.25, 10.60±0.29, 11.30±0.16, and 8.90±0.33, respectively. Compared with the control groups, the experimental groups displayed smaller urethral scar range, less severe scarring, improved Qmax rates and wider inner diameters (all P<0.05).

Conclusion

Urethral regional injection of verapamil intraoperatively or postoperatively can prevent overgrowth of urethral scar tissues after the transperineal anastomosis surgery, and reduce the tendency of postoperative restenosis of anterior urethral stricture.