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

Abstract

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. To assess the effect of BAUCs on the rate of UCF following single-stage primary hypospadias repair. 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. 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. 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. The meta-analysis herein suggests that using BAUCs may reduce UCF rates following hypospadias surgery. Rigorous prospective evaluation is needed to validate this benefit.