Single-stage salvage urethroplasty for failed distal hypospadias: comparison of Mathieu and grafted tubularised incised plate repairs

Abstract

Distal hypospadias repair is a common operation but some children require a complete salvage operation due to major complications of initial repair. The aim of this paper is to analyze the results of single-stage salvage distal hypospadias operations with salvage Mathieu (SM) and salvage grafted tubularised incised plate (SGTIP) techniques. A retrospective review of 115 children from 2 centers who underwent SM or SGTIP operations for failed distal hypospadias from January 2012 to July 2021 was conducted for demographic data, success of salvage operation and complications. Children with scarred urethral plate but with healthy, mobile ventral skin underwent SM operation, while children with a supple urethral plate of width 6mm or greater underwent SGTIP operation. Twenty-four (21%) children with pre-operative glans width < 12mm received pre-operative intramuscular testosterone injections (2 doses, 2mg/kg/dose). In the SM group, 22 cases with shallow, scarred glans underwent distal glans augmentation using the terminal portion of the Mathieu skin flap. Pre-operative and intra-operative parameters and post-operative results were compared between SM and SGTIP techniques. Statistical analysis was done using software; student t test and Fishers exact test were used, and p value of < 0.05 was considered significant. During the study period, SM and SGTIP operations were performed in 84 and 31 children, respectively. Overall, at a median follow-up of 24 (3-72) months, the salvage operation was successful in 101/115 (87.8%) patients; complications were observed in 14/115 (12.2%). The SM and SGTIP groups were comparable with respect to the number of prior failed operations, mean age, mean length of the distal urethral defect, pre-operative testosterone use and use of dorsal plication for chordee correction. SM had significantly better success (77/84, 91.6%) than SGTIP (24/31, 77.4%, p = 0.044). In the SM group, urethrocutaneous fistula (UCF) was noted in 2/84 (2.3%) while this was significantly higher (p = 0.01) at 5/31 (16.1%) in SGTIP. No patient in SM group developed meatal/urethral stenosis while this was significantly higher (p = 0.0003) at 6/31 (19.3%) in SGTIP; of these, 4 children had both UCF and meatal/urethral stenosis. A higher incidence of repair breakdown/dehiscence was seen in SM group, but the difference was not statistically significant (SM 5/84, 5.9% versus SGTIP 1/31, 3.2%, p = 0.484). In the SM group, two fistulae were successfully repaired after 6months, while the three cases of complete dehiscence underwent two-stage oral mucosal graft (OMG) repair. In the SGTIP group, two children underwent successful repair of UCF (one along with meatoplasty), one child with stenosis improved with urethral dilatations, while four children (three with UCF and stenosis and one with complete dehiscence) were managed with two-stage OMG repair. Single-stage salvage distal hypospadias repair was successful in 87.8% of patients. Both SM and SGTIP demonstrated acceptable results for salvage distal hypospadias repair. SM had better success and lower complications than SGTIP. SGTIP was associated with significantly higher post-operative UCF and meatal/neourethral stenosis.