Anatomical urethral meatus dimensions in distal hypospadias and their impact on postoperative outcome

Introduction. The most widely used operative technique for distal hypospadias is tubularized incised plate (TIP) urethroplasty. Despite its relative technical simplicity and favourable outcomes, TIP may be complicated by scarring of the distal urethra, meatal stenosis and urethrocutaneous fistulae, which may be related to a small glans and a narrow urethral plate. A grafted TIP (Grafted-TIP) modification has been proposed to address these issues; however, clear indications for its use in primary urethroplasty for distal hypospadias in children are lacking in the literature.

Objective. To assess the variability of urethral meatal anatomy and its impact on postoperative outcomes in boys undergoing repair of distal hypospadias.

Materials & methods. Between 2021 and 2022, 43 boys aged 10 months to 8 years underwent primary repair of distal hypospadias using the TIP technique. Intraoperative measurements of glans and urethral meatus dimensions were obtained with a calliper and ruler, recorded in a standardized datasheet, and subjected to subsequent statistical analysis. Based on published data on normal meatal anatomy in healthy boys (vertical meatal length 5.4 ± 1.0 mm), patients were stratified into two groups according to meatal size: group 1, meatal length < 0.05). The mean urinary flow rate was also higher in group 1, meatal length <5 mm; group 2, meatal
length ≥5 mm. Postoperative assessments were performed at 3 and 12 months and included cosmetic appearance, meatal position and size, and voiding parameters.

Results. The mean urethral plate width was significantly greater in group 2 than in group 1 (8.5 ± 1.7 vs 5.6 ± 2.6 mm, p< 0.05). The mean urinary flow rate was also higher in group 2 compared with group 1 (9.4 ± 2.1 vs 7.8 ± 3.3 ml/s). Postoperative complications were more frequent in group 1, although the difference was not statistically significant; the fistula rate was similar between groups, whereas no cases of wound dehiscence or cicatricial meatal stenosis occurred in group 2. HOPE score analysis showed no statistically significant difference between the groups (p > 0.05).

Conclusion. A vertical meatal length of 5 mm or greater appears to allow creation of a neomeatus comparable in size to that of healthy boys. This threshold is associated with a statistically significant improvement in urinary dynamics, reflected by higher mean urinary flow rates. Continued follow-up of this cohort will facilitate further evaluation of how anatomical characteristics of the penis in hypospadias influence long-term surgical outcomes.

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