Evaluating the literature on preoperative androgen stimulation for hypospadias repair using the fragility index - can we trust observational studies?

Preliminary Experience with Transdermal Preoperative Hormonal Treatment Before Severe Hypospadias Repair: Synergy Between Pediatric Surgeons and Endocrinologists

Objectives: The preoperative hormonal treatment (PHT) in eligible patients has the potential to become an asset for the treatment of severe hypospadias. The aim of the paper is to report the preliminary results on tolerability and efficacy of tailored transdermal PHT with testosterone before primary hypospadias repair, resulting by the joint activity between pediatric surgeons and endocrinologists. Methods: A retrospective study collected all the patients affected by severe hypospadias, with a glans width (GW) < 14 mm and/or a penile ventral curvature > 30°, treated with preoperative transdermal testosterone gel 2% at a standard dose of 2 mg/day after pediatric endocrinologist evaluation, from December 2020 to February 2024. Increases in GWs and penile lengths (PLs), together with adverse events and the rate of surgical complications, were reported. Results: During the period, ten patients were included and received transdermal PHT for 43 (±15) days on average. The treatment with PHT stopped 52 (±23) days before surgery. PL increased 0.76 (±0.27) cm (+37%) on average, and GW increased 0.42 (±0.26) cm (+40%). No adverse events were described. Three surgical complications were reported with an overall rate of 30%. Conclusions: Transdermal PHT was well-tolerated and showed a positive impact on the treatment of severe hypospadias. Future investigations might confirm these findings.

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

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.

Fragility of overactive bladder medication clinical trials: A systematic review

PURPOSE

Overactive bladder (OAB) syndrome significantly impairs quality of life, often necessitating pharmacological interventions with associated risks. The fragility of OAB trial outcomes, as measured by the fragility index (FI: smallest number of event changes to reverse statistical significance) and quotient (FQ: FI divided by total sample size expressed as a percentage), is critical yet unstudied.

MATERIALS AND METHODS

We conducted a systematic search for randomized controlled trials on OAB medications published between January 2000 and August 2023. Inclusion criteria were trials with two parallel arms reporting binary outcomes related to OAB medications. We extracted trial details, outcomes, and statistical tests employed. We calculated FI and FQ, analyzing associations with trial characteristics through linear regression.

RESULTS

We included 57 trials with a median sample size of 211 participants and a 12% median lost to follow-up. Most studies investigated anticholinergics (37/57, 65%). The median FI/FQ was 5/3.5%. Larger trials were less fragile (median FI 8; FQ 1.0%) compared to medium (FI: 4; FQ 2.5%) and small trials (FI: 4; FQ 8.3%). Double-blinded studies exhibited higher FQs (median 2.9%) than unblinded trials (6.7%). Primary and secondary outcomes had higher FIs (median 5 and 6, respectively) than adverse events (FI: 4). Each increase in 10 participants was associated with a +0.19 increase in FI (p < 0.001).

CONCLUSIONS

A change in outcome for a median of five participants, or 3.5% of the total sample size, could reverse the direction of statistical significance in OAB trials. Studies with larger sample sizes and efficacy outcomes from blinded trials were less fragile.

Current perspectives in hypospadias research: A scoping review of articles published in 2021 (Review)

Hundreds of papers are written about hypospadias every year referring to all aspects of the pathology, being one of the most common congenital malformations. The present study conducted a scoping review of articles published in 2021 to present the main issues and summarize current perspectives and achievements in the field. It searched for the keyword 'hypospadias' in the three most popular databases (PubMed, Scopus and Web of Science). After the analysis of the publications, they were categorized into different domains. The present review was performed respecting the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA ScR) guidelines. A total of 284 articles were included. These were published in 142 different journals. The most accessed was the Journal of Paediatric Urology with 54 articles. The main identified domains were related to surgical techniques, postoperative care, complications, anesthesia, anatomical factors, genetics, environmental factors, endocrinology, associated malformations, questionnaires and recommendations, management, biological materials, animal models, retrospective studies of centers, social media, bibliometrics, small gestational age, neoplasm, or fertility. Promising modifications of existing surgical techniques were presented with improved outcomes for both the proximal and distal types of hypospadias. Relevant anatomical and etiological, and also genetic factors were clarified. Aspects of the peri- and postoperative management referring to the antibiotherapy, analgesia, dressing techniques, and the future use of novel bioengineering agents to prevent, reduce or treat the occurring complications were discussed.

Effect of Preoperative Androgen Stimulation on Penile Size and Postoperative Complication Rate in Patients with Hypospadias: A Systematic Review and Meta-analysis

PURPOSE

To systematically review and evaluate the beneficial effects of preoperative androgen stimulation (PAS) on penile length, glans width, and postoperative complications in patients with hypospadias using meta-analysis.

MATERIALS AND METHODS

A comprehensive search of the published literature between 1980 and 2022 was done on PubMed, Embase, Google Scholar, Scopus, Web of Science, and Proquest. Studies of patients with 5-alpha reductase deficiency, differentiation sex disorder, or micro-penis without hypospadias were excluded. The full-text screening, quality assessment, and data acquisition were done independently by two reviewers. Meta-analysis was done to quantify the penile growth and postoperative complications.

RESULTS

The initial literature search yielded 2,389 records, wherein 32 studies were eligible for the systematic review and meta-analysis. Preoperative testosterone stimulation increased the penile length and glans width by 9.34 mm (95% CI: 6.71-11.97) and 3.26 mm (95% CI: 2.50-4.02), respectively. A longer penis at the baseline led to greater length gain following treatment (1 mm longer at the baseline was likely to gain 0.5 mm more). However, the increase in penile length was not associated with the severity of hypospadias. While the treatment did not affect the overall complication rate, the postoperative fistula risk was lower in those receiving PAS (RR=0.52, 95% CI: 0.30-0.91, p=0.02).

CONCLUSIONS

The beneficial effects of PAS on increasing the penile length and glans width were again confirmed. More gain of penile length was expected in the larger penis at baseline. There are no reported increased postoperative complications in association with PAS.

Paediatric surgical trials, their fragility index, and why to avoid using it to evaluate results

BACKGROUND

The fragility index has been gaining ground in the evaluation of comparative clinical studies. Many scientists evaluated trials in their fields and deemed them to be fragile, although there is no consensus on the definition of fragility. We aimed to calculate the fragility index and its permutations for paediatric surgical trials.

METHODS

We searched pubmed for prospectively conducted paediatric surgical trials with intervention and control group without limitations and calculated their (reverse) fragility indices and respective quotients along with posthoc-power. Relationships between variables were evaluated using Spearman's ρ. We also calculated S values by negative log transformation base-2 of P values.

RESULTS

Of 516 retrieved records, we included 87. The median fragility index was 1.5 (interquartile range: 0-4) and the median reverse fragility index was 3 (interquartile range: 2-4), although they were statistically not different (Mood's test: χ² = 0.557, df = 1, P = 0.4556). P values and fragility indices were strongly inversely correlated (ρ = - 0.71, 95% confidence interval: - 0.53 to - 0.85, P < 0.0001), while reverse fragility indices were moderately correlated to P values (ρ = 0.5, 95% confidence interval: 0.37-0.62, P < 0.0001). A fragility index of 1 resulted from P values between 0.039 and 0.003, which resulted in S values between 4 and 8.

CONCLUSIONS

Fragility indices, reverse fragility indices, and their respective fragility quotients of paediatric surgical trials are low. The fragility index can be viewed as no more than a transformed P value with even more substantial limitations. Its inherent penalisation of small studies irrespective of their clinical relevance is particularly harmful for paediatric surgery. Consequently, the fragility index should be avoided.