Comparative analysis of tubularized incised plate vs. onlay island flap uretrhoplasties for penoscrotal hypospadias

PurposeTo review our experience with penoscrotal hypospadias (PSH), comparing the results of TIP vs. transverse island flap ONLAY urethroplasties.Material and methodsA retrospective review of consecutive patients with PSH was performed. 1657 boys underwent hypospadias repair at our institution from 1998 to 2006. 75 comprised our study population: 35 children underwent a TIP repair, and 40 had an ONLAY procedure. Degree of chordee, type of chordee repair, complications, available uroflowmetry in toliet trained-pts., and number of re-operations were compared between the 2 groups.ResultsMean age was 17m (9-91) for TIP and 17.8m (10-58) for ONLAY. Mean follow up was 30m (6-74) and 38.8m (16-80), respectively.VariablesTIP n=35 (%)ONLAY n=40 (%)pPreop severe chordee (> 45o)7 (20)18 (45)0.02Dorsal plication19 (54.3)27 (67.5)Mean catheter duration (days)8.5 (7-10)10.3 (7-14)Overall complication21 (60)18 (45)NSFistula/Breakdown18 (51.4)10 (25)0.01Fistula location (proximal)13/18 (72.2)2/10 (20)0.02Recurrent chordee2 (5.7)5 (12.5)Average flow rate3.1 to 13.23.0 to 16.0Flattened shape curve16/24 (66.6)7/21 (33.3)<0.01PVR >30% expected blad capac2/24 (8.3)0/21 (0)# pts with >2 re-operations2 (5.7)7 (17.5)ConclusionsThe overall complication rate was similar for long penoscrotal TIP and ONLAY urethroplasties. The TIP-fistula rate was higher vs. ONLAYS, though catheter duration was the same in both groups. While PVRs were not elevated, more flattened flow curves may suggest that TIP-urethroplasty is narrower and thus, behaves as a relatively “distal resistance” prompting to more proximal fistula formation. Thus, the TIP-fistula rate may benefit from more delayed catheter removal or deeper plate incision. Nevertheless, both techniques appear to be equivalent approaches to correct PSH. Longer follow-up may reveal more divergent outcomes for these 2 approaches.