Usefulness topical di-hydro testosterone prior to proximal hypospadias repair in testosterone non-responders

Abstract

Background and aims

Preoperative hormonal stimulation (PHS) with testosterone is commonly used to enhance glans width in hypospadias repair. However, up to 50 % of those with proximal hypospadias do not respond to testosterone due to receptor resistance or failure of testosterone conversion to di-hydro testosterone (DHT). There are limited reports on DHT usage in testosterone non-responders. This study aimed to evaluate the efficacy and safety of topical DHT in testosterone-resistant proximal hypospadias cases. We hypothesized that DHT enhances glans width without additional complications.

Methods

122 children with proximal hypospadias (46XY) and bilateral descended testes were treated at two centres. Glans width was measured to assess testosterone response. In testosterone non-responders 2.5 % DHT gel was applied topically for 2 months. Staged correction involved first stage Byar's flaps after ventral curvature correction and a second stage Duplay repair 6–12 months later. DHT was used prior to both stages and application ceased two months prior to each stage. Patients were followed-up for 1-year to assess functional and cosmetic complications (summary figure).

Results

Among 40 testosterone-resistant patients (32.8 %; 95 % CI 25–41 %) DHT increased mean glans width significantly from 10.2 mm to 14.5 mm (p = 0.01). Reversible androgenic effects included prepubic hair growth (22.5 %) and erections (12.5 %). No significant adverse effects like tissue necrosis or excess bleeding were observed. At first stage, adequate flap uptake and penile curvature correction were achieved. Post-second stage, the complication rate was low (5 %), with one fistula and one meatal retraction. Parental satisfaction was high, with 90 % rating outcomes as satisfactory or very satisfactory.

Discussion

In this study we encountered testosterone resistance in 32.8 % and in this group topical DHT application was effective in increasing the glans width. Angiogenesis effects of DHT has been said to act as an adjunct to wound healing. At first stage repair thanks to DHT effect the quality of foreskin improved and the glans became wide to be splayed open adequately. There were no significant hormonal side effects as we stopped DHT promptly when excess hair growth or erections were encountered.

Application of DHT between first and second stage helped to smoothen the neo-urethral plate and increase vascularity. PHS with DHT is an effective alternative for managing testosterone resistant proximal hypospadias. It helps in significantly enhancing glans width, surgical outcomes, and satisfaction rates while maintaining a low complication rate. The study's limitations include a small sample size, lack of genetic evaluation for androgen resistance, and short follow-up.

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Summary figure. Role of topical DHT in proximal hypospadias. a) At recruitment before DHT; b) after one month of topical DHT; c) midline scar 1 month after first stage Byars flap/ before repeat DHT; d)urethral plate supple and vascular on massaging it for a month with DHT gel after first stage e) Second stage repair immediate post-op f) Slit like terminal meatus at 1-year follow-up. DHT is applied for a total of 4-6 months; initially 2-3 months prior to first stage and again for 2-3 months prior to second stage. Each stage performed leaving 2-months gap without DHT.