Role of uroflowmetry before and after hypospadias repair

Abstract

Aims: To study the role of uroflowmetry in the preoperative and early postoperative period in children undergoing hypospadias repair.

Materials and methods: Twenty-six cases undergoing hypospadias repair over 1 year (tubularized incised plate [TIP] Snodgrass [17 patients], TIP with Snodgraft [5 patients], Duckett's onlay flap [2 patients], and Duckett's tube [2 patients] urethroplasty) were prospectively evaluated with preoperative ultrasound and uroflowmetry and postoperative uroflowmetry at 3 months after the surgery and at 6 and 9 months interval if these dates fell within the study period on follow-up. The parameters studied were maximum flow rate (Q_max), average flow rate (Q_av), total voided volume, voiding time, and type of curve. Preoperative and postoperative uroflow data were compared.

Results: Twenty-six cases comprised of anterior hypospadias (n = 8), mid penile (n = 11), and posterior hypospadias (n = 7). Fourteen patients had obstructed flow rates preoperatively. While 69% patients (18/26) had obstructed flow rates at 3 months postoperatively, it dropped to 43% at 9 months. Following TIP (Snodgrass) repair, 88% (15/17) had obstructed flow rates postoperatively. Best results were seen in patients undergoing circumferentially epithelialized urethral reconstruction (TIP with Snodgraft, Duckett's onlay flap, and Duckett's tube).

Conclusions: Abnormal uroflow is an inherent aspect of hypospadias in 50% of the cases. Both preoperative and postoperative uroflow evaluation is necessary for meaningful conclusion. Patients with preoperative normal flow rates but obstructed postoperative flow rates need clinical evaluation. Obstructive flow rates are more common after TIP (Snodgrass) repair. The urinary flow rates improve with time.

Keywords: Hypospadias; nomograms; postoperative period; preoperative period; urethra.