Comparison of Transverse Island Flap Onlay and Tubularized Incised-Plate Urethroplasties for Primary Proximal Hypospadias: A Systematic Review and Meta-Analysis

Abstract

PurposeThis meta-analysis was conducted to compare postoperative outcomes between transverse island flap (TVIF) onlay and tubularized incised-plate (TIP) urethroplasties for primary proximal hypospadias.Materials and MethodsA comprehensive literature search updated to 21st May 2014 was carried out for relevant studies. After literature identification and data extraction, odds ratio (OR) with 95% confidential interval (CI) was calculated to compare postoperative complication rate between TVIF onlay and TIP. Meta-regression and subgroup analyses were applied to find potential affective factors.ResultsA total of 6 studies including 309 patients receiving TVIF onlay and 262 individuals subjected to TIP met inclusion criteria. The synthetic data suggested that TVIF onlay and TIP were comparable in terms of total complication rate (OR 0.85, 95% CI 0.56–1.30, p = 0.461), fistula (OR 0.68, 95% CI 0.38–1.21, p = 0.194), recurrent curvature (OR 1.16, 95% CI 0.43–3.12, p = 0.766), dehiscence (OR 0.95, 95% CI 0.33–2.74, p = 0.920), diverticulum (OR 1.90, 95% CI 0.53–6.78, p = 0.321), meatal stenosis (OR 0.74, 95% CI 0.20–2.77, p = 0.651) and urethral stricture (OR 1.49, 95% CI 0.41–5.50, p = 0.545), without significant heterogeneity for each comparison group. Meta-regression and subgroup analyses revealed no significant findings. One-way sensitivity analysis indicated that the results were stable. No publication bias was detected using both funnel plot and Egger’s test. Also, there were no obvious differences observed in cosmetic and functional outcomes.ConclusionsThis meta-analysis suggests that TVIF onlay and TIP urethroplasties are clinically equivalent. Given the inherent limitations of included studies, this conclusion should be interpreted with caution and wait to be confirmed by more well-designed randomized controlled trials with high quality in the future.

Width proportion of the urethral plate to the glans can serve as an appraisal index of the urethral plate in hypospadias repair

“…Given the higher UC incidence of 22.3% in U/G ≤0.36, it might be necessary to reconsider the limitation of TIP procedures in patients with an unhealthy urethral plate. Subsequently, other urethral plate preserving procedures might be more suitable in these patients, such as transverse island flap onlay or TIP with inlay grafting relying less on urethral plate quality . Further randomized controlled trials of these urethral plate preserving procedures is imperative in hypospadias patients with U/G ≤0.36.…”

Current hypospadias management: Diagnosis, surgical management, and long-term patient-centred outcomes

“…50,51 A systematic review comparing TIP to onlay preputial flaps for proximal hypospadias without significant VC showed no significant difference in urethroplasty complication rates. 52 The Koyanagi repair has shown favourable results for proximal hypospadias, with a 17% complication rate in a series of 151 proximal hypospadias children. 53 Two-stage repairs for proximal hypospadias repair in boys with >30°V C provides a reliable and reproducible option for success, although the evidence for this approach is weak.…”

Primary hypospadias repair techniques: A review of the evidence

“…[20] Mean patient age, the proportion of penile shaft and penoscrotal cases, and the mean duration of follow-up was similar for both techniques. Meta-analysis evaluated urethroplasty complications, reporting similar overall rates (odds ratio [OR] 0.85, 95% confidence interval [CI] 0.56–1.30, P = 0.46), and similar odds for fistulas (OR 0.68, 95% CI 0.38–1.21, P = 0.19), recurrent ventral curvature (OR 1.16, 95% CI 0.43–3.12), P = 0.76), dehiscence (OR 0.95, 95% CI 0.33–2.74, P = 0.92), diverticulum (OR 1.90, 95% CI 0.53–6.78, P = 0.32), meatal stenosis (OR 0.74, 95% CI 0.20–2.77, P = 0.65), and urethral stricture (OR 1.49, 95% CI 0.41–5.50, P = 0.54).…”

“…[20] found only two comparative uroflow studies, one reporting no difference in TIP versus onlay, and the other stating Qmax and Qave was significantly less after TIP in boys a mean age of 5 years.…”

“…[20] found two studies using the pediatric penile perception score to compare proximal TIP and onlay (meatus, glans, penile shaft, overall appearance), both stating there was no difference in results.…”