Prognostic surgical factors related to short term urethroplasty complications after Tubularized Incised urethral Plate Urethroplasty in distal- and mid-type hypospadias in the Dutch Hypospadias Study

INTRODUCTION: Complications after hypospadias surgery are not rare and vary considerably between series in literature. In 2008 a national prospective observational cohort study was initiated, called the "Dutch Hypospadias Study" (DHS), to evaluate and possibly improve the outcomes of hypospadias surgery. The objective of the current study is to identify possible prognostic surgical factors for urethroplasty complications (UC) in the subgroup who underwent a Tubularized Incised urethral Plate Urethroplasty (TIPU) for distal and mid-type hypospadias. UC is defined as the sum of fistula, dehiscence, meatal/urethral stenosis and urethral diverticulum. PATIENTS AND METHODS: This TIPU subgroup patients were included in the DHS between September 2008 and June 2016. Patient and disorder characteristics, details of surgical technique, pictures of anatomic appearance and complications are documented in a "web based" database. The outcomes concerning UC-rates at six months after TIPU were analysed and possible prognostic surgical factors were explored. RESULTS: A total of 723 cases (age range 6.1-54 months; median age 12 months; Inter Quartile Range (IQR) 9-14 months) were evaluated 6 months after surgical correction. A preputium reconstruction was done in 163 patients (23 %). Of these, 31 did not have a retractable foreskin which makes the total number of evaluable patients for UC 692 cases. After photo review, initially underreported dehiscence rate was doubled from 6 to 12 %. The UC-rate is 23 % with a variation of 3-44 % between the surgeons. Multivariable analysis identified the following surgical variables associated with a lower relative risk for UC: subepithelial urethroplasty suture technique (versus transepithelial technique), the running urethroplasty suture technique (versus interrupted technique) and the use of a Ch 6 or 8 catheter during urethroplasty (versus Ch 10, 12 or 14 catheter). DISCUSSION: Technical factors including suture technique and catheter size impact UC. Limitations include observational (non-randomized) study design, lack of glans size and urethral plate characteristics in the dataset, and single-layer (vs 2-layer) urethroplasty in 93 % patients precluding analysis of a another technical factor. CONCLUSION: This study identifies the following 3 different details in urethroplasty technique as relative risk factors for short term UC: the subepithelial suture technique, the running suture technique and the use of a smaller catheter are associated with a lower risk for UC compared to respective the transepithelial technique, the interrupted sutures and the use of a larger catheter. For hypospadias surgeons these associations can serve as important tools to improve their outcomes if necessary.