Analysis of risk factors for recurrent urethral stricture after excision and primary anastomotic urethroplasty

Objective To analysis the risk factors for stricture recurrence after excision and primary anastomotic urethroplasty(EPA). Methods 209 urethral stricture cases managed with EPA were retrospectively studied from January 2017 to December 2018 in our center. Of all the patients, 183 cases were diagnosed as posterior urethral stricture and 26 cases were diagnosed as bulbar urethral stricture. Their age ranged from 5 to 78 years(mean 42.1 years). 25 cases(12.0%) were defined as the obesity, whose BMI was more than 28 kg/m2. 12 cases(5.7%) has the history of diabetes mellitus. 103 cases(49.3%) smoked at least three months before operation. 127 cases(60.8%) didn't have the history of dilation. 42 cases(20.1%)had the history of dilation once or twice. 40 cases (19.1%)had the history of dilation more than three times. The history of urethroplasty included once in 38 cases(18.2%)and more than twice in 8 cases(3.8%). The location of stricture included posterior urethral stricture in 183 cases and bulbar stricture in 26 cases. The history of stricture ranged from 1 to 360 months(mean 35.1 months). The stricture length was(3.19±0.65)cm. The causes including trauma in 190 cases, iatrogenic urethral injury in 12 cases, inflammatory in 2 cases and others in 5 cases. The standard of stricture recurrence were defined as the urination difficulty after removal of catheter and endoscopic or radiographic evidence of obstruction in the area of repair. Univariate and multivariate analysis were performed by the use of Cox′s proportional hazards regression model to identify the related factors for stricture recurrence. Result The following up period was ranged from 3 to 32 months(average 18.78 months). Recurrence occurred in 31 cases in the period of 1.0 to 18.0 months(average 5.34 months). Factors had statistical differences in univariate analysis including stricture period(HR=1.007, P<0.001), stricture length(HR=5.334, P<0.001), history of direct vision internal urethrotomy (DVIU)(HR=2.901, P=0.003), history of urethral dilation ≥3 times(HR=6.214, P<0.001), history of urethroplasty 1 time, ≥2 times(HR=4.175, P=0.001, HR=9.885, P<0.001), 3 months smoking before surgery(HR=2.605, P=0.016), suprapubic cystostomy(HR=0.231, P=0.006), inferior pubectomy(HR=6.603, P<0.001). In multivariate analysis stricture length(HR=4.911, P<0.001), history of urethroplasty 1 time, ≥2 times(HR=2.387, P=0.045, HR=3.688, P=0.015), 3 months smoking before surgery(HR=2.730, P=0.030)were independent risk factors. Conclusion The urethral stricture recurrence mainly occurred within 6 months after surgery. The length of stricture, history of urethroplasty and 3 months smoking before surgery were the independent risk factors for stricture recurrence. Key words: Urethral stricture; Anastomotic urethroplasty; Stricture recurrence; Risk factors