Biologic adjuvant urethral coverings for single-stage primary hypospadias repairs: A systematic review and pooled proportional meta-analysis of postoperative urethrocutaneous fistulas

Abstract

Background: The use of barrier layers between the neourethra and skin is associated with lower rates of post-operative urethrocutaneous fistula (UCF) following hypospadias surgery. Recent studies have evaluated the ability of biologic adjuvant urethral coverings (BAUCs) - namely acellular matrix (AM), tissue adhesives (TAs), and autologous platelet-rich plasma or fibrin (PRP/PRF) - to prevent wound complications following hypospadias surgery. In general, however, these studies are small and conducted at single institutions.

Objective: To assess the effect of BAUCs on the rate of UCF following single-stage primary hypospadias repair.

Methods: We conducted a systematic review of studies reporting the rate of postoperative UCF in pediatric patients undergoing single-stage, primary hypospadias repairs using either AM, TA, or PRP/PRF as a layer interposed between the neourethra and skin. We then performed a pooled proportional meta-analysis of post-operative UCF. Patients within each study who underwent comparable surgery but did not receive a BAUC were used as controls.

Results: 10 studies were included in our review. The meta-analysis included 280 patients from 7 studies who underwent hypospadias repairs with BAUCs. The pooled incidence of UCF was 10% (95% CI 6-14%). Mean follow-up ranged 5-23.5 months in the 5/7 studies reporting specific durations, and ≥6 month and 14-30 months, respectively, in the other two studies. Patients in whom a BAUC was used had significantly lower odds of UCF than control patients (OR 0.39, 95% CI 0.24-0.64, p = 0.0002). In subgroup analyses, significant superiority held for AM and TA; proximal or penoscrotal cases; transverse preputial island flap (TPIF) technique; when both cases and controls had local flaps; and when neither cases nor controls had flaps.

Discussion: The use of BAUCs was associated with decreased rates of post-operative UCF in single-stage primary hypospadias repairs and may be most beneficial in more severe cases and when used in addition to local flaps or when using a flap is not possible. In 2/3 studies of PRP/PRF and 2/4 studies of tubularized incised plate (TIP) technique, dartos flaps were used in controls but not BAUC patients, which may explain the lack of benefit demonstrated for these subgroups. This meta-analysis is limited by the quality of evidence in the included studies, which are not uniformly randomized. Furthermore, the follow-up durations and methods for assessing complications are not standardized between included studies.

Conclusion: The meta-analysis herein suggests that using BAUCs may reduce UCF rates following hypospadias surgery. Rigorous prospective evaluation is needed to validate this benefit.

Keywords: Biological products; Hypospadias; Urinary fistula.