Factors Related To Penile Straightening In Hypospadias With Ventral Curvature And Development Of Predictive Nomograms

Background and Objective:Hypospadias is one of the most common congenital urologic conditions and the prevalence of hypospadias is roughly 1 in 300 male births.Besides of the abnormal urethra location on the ventral part of the penis,patients of hypospadias associated with other variable genital deformities,including urethral hypoplasia,aborted development of urethral spongiosum,penile curvature,cryptorchidism and penoscrotal transposition.Hundreds of different urethroplasty and associated reconstructive techniques have been reported for hypospadias surgical repairs over years,and remaining the only method in dealing with hypospadias.Despite the steadily improving results after continuously developing distal hypospadias surgery including TIP or Onlay for one-stage repair in the past two decades,it is still a major concern for urologists.For proximal types with sever ventral curvature,the discussion whether it is most appropriate to perform a single-stage or a two-stage approach is still ongoing.However,the rate of complications may be underestimated due to relatively short-term follow-up in the majority of series,and the long-term follow-up results of surgery are still unfavourable with reported complication rate as high as 50% or above,especially ventral recurrence.As far as the functional and cosmetic outcomes are concerned,hypospadias with untreated ventral curvature may experience several additional surgeries to finish the treatment.At present,there is not a complete clinical database for hypospadias and it is not clear which procedure of ventral curvature correction or factors will after the result of penile straightening during operation.In this study,the correction between the clinical dates of patients after various types of straightening procedures were analyzed and factors that may affect the results were screened out to construct a predictive model for guiding clinicians in choosing the optimal strategy.Methods and Materials: Clinical data of 742 hypospadias patients who underwent procedures of penile straightening and urethroplasty in Shanghai Children’s Hospital between February 2015 and October 2020 were prospectively collected,including 8 clinical factors before and after skin degloving(urethral meatus,degree of ventral curvature,strength penile length,etc.).The incidence of penile straightening after skin degloving or urethral plate transection was confirmed by artificial erection before and after each step of curvature correction.Univariate and multivariate logistic regression analysis were used to analyze the relationship of these features between groups of penile straightening or not after after skin degloving or urethral plate transection,also patients of ventral curvature correction after urethral plate transection and dorsal plication.Nomograms were formulated based on the results of multivariate analysis and by using the package of rms in R version 4.0.3 and SPSS 24.0.The Receiver Operating Characteristic(ROC)curve was constructed by R software,and the area under the curve and the value of cut-off were calculated.Results: A total of 742 patients were included in this study,including164 patients with straight penile and 578 without after skin degloving.By comparing the clinical data between the two groups,the study showed that the difference of urethral meatus and degree of penile curvature before degloving were statistically significant(P<0.05).Of the 436 cases of patients who underwent urethral plate transection,257 patients with straight penile and 179 without.By comparing the clinical data between the two groups,the study showed that the difference of degree of penile curvature and strength penile length after degloving were statistically significant(P<0.05).With the meatus location,urethral defect,degree of curvature after degloving and penoscrotal transposition,the difference was statistically significant(P<0.05)between patients with penile straightening after urethral plate transection(n=257)and dorsal plication(n=119).Through Logistic regression analysis,the prediction models were established and the area under the ROC curve was 0.82,0.75 and 0.88,respectively.Conclusions: Ventral curvature is a common deformity associated with hypospadias,which affects the decision of which procedure to take among various type of penile straightening and urethroplasty.This study showed that the success rate of curvature correction after skin degloving and urethral plate transection was 22.1% and 58.9%.It was found that meatus location,degree of curvature,penoscrotal transposition,urethral defect and strength penile length were associated with penile straightening after various procedures of curvature correction.According to the nomograms of predictive models constructed by this study,it is possible to predict the incidence of penile straightening after procedures such as skin degloving,urethral plate transection and dorsal plication,which offers strong reference value in clinical practice.