Study On Urinary Flow Rate Combined With Postvoid Residual Urine Before And After Snodgrass Therapy For Coronal Hypospadias

ObjectiveHypospadias is a common congenital malformation in children with genitourinary system.Surgical treatment is still the main treatment procedure for this disease.However,complications after hypospadias are frequently confronted,including urethral stricture and urinary fistula,etc.How to find and deal with these complications in time is still a challenging for most urologists.In this study,we compared the differences and characteristics of uroflowmetry(UFM)and post-void residual urine(PVR)in patients with coronary urethral hypospadias before and after urethroplasty with coiled urethroplasty(Snodgrass)and evaluated its clinic application in early diagnosis of urethral structure after operation.And provide guidance for the treatment of urethral dilatation after operation..MethodsThis study retrospectively analyzed the clinical data of 298 children with coronary sulcus hypospadias who underwent Snodgrass operation from January 2012 to December 2017.It was recorded that relevant data such as the patient’s age,operation time,various urodynamic parameters before and after operation,and the bladder and upper urinary tract morphology of the child before and after operation.Evaluate the urethral condition of children with hypospadias and compare the differences of various urodynamic parameters before and after surgery.Urine flow rate meter records the urine flow curve,maximum flow rate(Qmax),average flow rate(Qave),voided volume(VV),flow time(TQ/FT),and time to maximum flow(TQmax).The PVR was measured by ultrasound and the bladder and upper urinary tract morphology were examined.ResultsThere was no significant difference of the ultrasonic morphology of the bladders and upper urimry tracts in all children with coronal hypospadias.All children were 2 to 11 years old,with an average age of(4.9±2.3)years;the operation time(ie,operation age)was 0.6 to 9 years,and the average operation age was(3.8±2.1)years.Among them,there were 15 cases in the urethral stricture group and 283 cases in the non-urethral stricture group.There was no statistically significant difference in age between the two groups and the age of surgery(P>0.05).All patients with coronal hypospadias at different ages had lower Qmax before and after surgery than normal children.Of the patients with stenosis at 3 months after surgery,the maximum flow rate(Qmax)was(7.18±1.96)ml/s,the average flow rate(Qave)was(5.28±1.07)ml/s,voiding time was(31.72±5.47)s,maximum flow time was(15.88±3.94)s,the voided volume was(138.23±7.50)ml,and postvoid residual urine was(19.26±3.84)ml.Of the non-stenosis group,the Qmax was(8.09±1.39)ml/s,the Qave was(6.45±1.34)ml/s,voiding time was(29.05±4.59)s,maximum flow time was(9.31±2.76)s,the voided volume was(133.87±9.11)ml,and postvoid residual urine was(16.42±4.31)ml.It can be seen that the maximum flow rate and average flow rate of the stenosis group are smaller than that of the non-stenosis group,and the maximum urine flow time of the stenosis group is longer than that of the non-stenosis group.Of the patients with stenosis at 3 months after surgery,13.3%patients had bell-shaoed uroflow curve,and 66.7%had platform uroflow curve;while 26.1%of the non-stenosis group had bell-shaoed uroflow curve,and 45.6%had platform uroflow curve.All children with urethral stricture were given regular urethral dilatation treatment.The results of UFM combined with PVR at the 6-month postoperative review were significantly improved compared to the 3-month postoperative period.The difference of the uroflow curve between the 2 groups was significant.At the same time,it was found that the results of the 6-month postoperative review were similar to those of the 3-month postoperative review,and there was no significant difference between the results of 2-week postoperative stenosis groups and those of the non-stenosis groups.However,it should be noted that all the indicators of all the patients showed a gradual recovery trend 2 weeks,3 months and 6 months after surgery.All children in the stenosis group were given urethral dilatation after stenosis was found.ConclusionUFM combined with postvoid residual urine after Snodgrass therapy for coronal hypospadias can be used to detect earlypostoperative urethral stricture,in particular,within 3 months after surgery to review more meaningful.UFM combined with PVR examination provides an objective,simple and noninvasive diagnostic method and laboratory basis for the clinical diagnosis of urethral stricture after operation of hypospadias.It also provides guidance for the treatment of urethral dilatation after stenosis.