Urethral plate quality assessment and its impact on hypospadias repair outcomes: A systematic review and quality assessment

BACKGROUND: The variability of the urethral plate (UP) characteristics is one of the factors that influence technical choices for hypospadias correction. However, it is difficult to objectively evaluate the UP, leading to controversies in this subject, and vague terms utilized in the literature to describe its characteristics. OBJECTIVE: We aim to analyze the previously described methods used to characterize and evaluate UP quality, emphasizing the pros and cons of each system, and highlighting its possible influence on different postoperative outcomes. METHODS: We searched the databases PubMed, Embase, and Cochrane Library CENTRAL from January 1, 2000 to August 20, 2020. The following concepts were searched: urethra reconstruction/urethra replacement/urethroplasty AND hypospadias/hypospadias, AND children AND "plate" with the gray literature search. Subgroup analyses were also carried out. The quality of the involved studies was reviewed operating a modified version of the Newcastle-Ottawa Scale (NOS). RESULTS: 996 citations perceived as relevant to screening were retrieved. Thirteen studies were included comprising a total of 1552 cases. The number of patients in each study varied between 42 and 442, and the average post-surgical follow-up duration ranged between 6 months and twenty-six months. All studies used postoperative urethral stents of variable sizes and types. The impact of UP was most frequently assessed for cases treated with the tubularized incised plate (TIP) repair. CONCLUSION: The UP quality seems to play a role as an independent factor influencing postoperative outcomes of hypospadias repair. Currently used strategies for the appraisal of UP quality are highly subjective with a low index of generalizability. Various attempts to overcome these limitations exist but none was consistently accepted, leaving a wide space for creative investigation in order to obtain an objective, reproducible, precise, and well-validated tool.