Tubularized Incised Plate (TIP) Repair Improves Outcome of Hypospadias Repair

Abstract

. There were no changes in the suture material used. The operative interventions were performed by two pediatric surgeons with 24 and 11 years' experience in hypospadias surgery respectively. All complications were handled by the same team of surgeons.The main outcome measure was any complication calling for a reoperation: a fistula, rupture and/or stricture, during the period from the operative intervention until August 2016, the endpoint of the study. The Methods of Operation Mathieu repairDuring a Mathieu procedure [1] a skin flap based towards the meatus [8] is turned 180 degrees and sutured into incision on both sides of the glanular groove and along the tip. Curvature is corrected when present. The prepuce is then partially divided and mobilized to create an outer layer. Tubularized Incised Plate repair (TIP)When a TIP repair [2] is performed a U-shaped skin incision is made along the edges of the urethral plate and the penis is degloved. The urethral plate is widened by a midline incision along its length and then tubularized over a stent. A pedicle of subcutaneous tissue is dissected from the ventral or dorsal penile skin and used to cover the neourethra. Finally, the glanular wings, mucosal collar and ventral penile skin are closed in the midline. Statistical considerationsA clinical significant relevance was set at a decrease in the complication rate with 20% units. The intention was to study independent cases and controls with 1 control(s) per case. Prior data indicate that the probability of exposure among controls is 0.3. If the true probability of exposure among cases is 0.1, we will need to study 72 case patients and 72 control patients to be able to reject the null hypothesis that the exposure rates for case and controls are equal with probability (power) 0.8. The Type I error probability associated with this test of this null hypothesis is 0.05. We will use a continuitycorrected chi-squared statistic or Fisher's exact test to evaluate this null hypothesis. Methods: Over a period of six years, the Mathieu procedure was replaced by the Tubularized Incised Plate (TIP) repair as the most favored method of grade 1-2 hypospadias repair at our clinic. All operated boys were prospectively registered during those years. Two three-year-periods were outlined with equal number of patients: 2010-2012 and 2013-2015, but with the preferred method of repair reversed. The end point was any complication calling for a reoperation. Hans Winberg*, Magnus Anderberg and Einar Arnbjörnsson Main results:In the first period 69 boys were operated whereof 50 Mathieu and 19 TIP. 35 (51%) boys required a reoperation. In the second period 73 boys were operated whereof 19 Mathieu and 54 TIP. 15 (21%) required a reoperation, P < 0.01. Research limitations:The study is prospective but the technique preferred was the choice of the surgeon. Follow up will be continued due to acknowledged accumulation of complications over time. Conclusion:Method seems to matter. Advantage TIP. We are not aware of any other prospective study follo...