Pre-incision urethral plate width does not impact short-term Tubularized Incised Plate urethroplasty outcomes

Abstract

Two reports have found that urethral plate (UP) widths <8mm before tubularized incised plate (TIP) incision increased urethroplasty complications. The present study measured pre-incision UP width in consecutive boys undergoing TIP to determine if it affected outcomes. The present study followed the method previously used by Holland and Smith, and Sarhan etal. to measure UP width before creating glans wings or performing midline plate incision in consecutive patients with primary hypospadias and ventral curvature <30°, who all underwent TIP repair (Summary Fig.). Glans width at its widest point was also measured. Multiple logistic regression assessed urethroplasty complications (fistula, glans dehiscence, meatal stenosis/urethral stricture, diverticulum) based on pre-incision UP width, glans width, patient age, and meatal location. The UP widths were determined in 224 consecutive primary TIP repairs during 2012-2015: 200 distal, 11 midshaft, and 13 proximal. The UP width was <8mm in 192/224 (86%) patients. Mean pre-incision width was 6.1mm (SD 1.5, range 2-11), without difference in UP widths according to meatal location (P=0.06). Mean post-incision UP width was 12mm (SD 2.2, range 10-16). Mean change in width after incision (delta/original UP width) was 116% (SD 63, range 20-250). There was follow-up in 186 patients for a mean of 6 months. Urethroplasty complications (five fistulas, six glans dehiscence) were diagnosed in 11 (6%): 9/165 distal, 1/9 midshaft, and 1/12 proximal repairs. There was no difference in those <8 vs ≥8mm (11/160 vs 0/26, P=0.17). Similarly, UP width was not different between patients with and without urethroplasty complications. Multiple logistic regression in these 186 patients - including meatal location, UP width, glans width, and age - found only glans width <14mm was associated with increased odds of urethroplasty complications (OR 19.2, 95% CI 3.5-106, AUC=0.799). The data show that pre-incision UP width is not an independent risk factor for urethroplasty complications. However, it is possible that technical factors, such as how deeply the dorsal incision is made or size of the urethral stent, might contribute to this finding by other authors. After watching the TIP repair, Smith stated that the plate incision was deeper than he made. Sarhan etal. reported a mean change of 57% in UP width after incision, whereas the present one was double at 116% (i.e. from 6mm pre-incision to 12mm post incision), and they used an 8-Fr catheter. While they stated that they incised the plate deeply, the lower percentage increase in width suggests that it was not as deep as was recommended. The UP width before incision did not increase urethroplasty complications. Surgeons do not need to measure or categorize the UP to determine suitability for TIP repair, as long as the plate incision is made deeply to the corpora.