Use of holmium laser for urethral strictures in pediatrics: A prospective study.
INTRODUCTION
The management of urethral strictures is very challenging and requires the wide expertise of different treatment modalities ranging from endoscopic procedures to open surgical interventions.


OBJECTIVE
To assess the effectiveness and complications of retrograde endoscopic holmium: yttrium-aluminum-garnet laser (Ho: YAG) urethrotomy (HLU) for the treatment of pediatric urethral strictures.


PATIENTS AND METHODS
From January 2010 to January 2013, 29 male pediatric patients with a mean age of 5.9 years and primary urethral strictures 0.5-2 cm long were treated using HLU. The stricture length was <1 cm in 16 (55%) patients and >1 cm in 13 (45%). Fifteen (51.7%) patients had an anterior urethral stricture, while 14 (48.3%) had a posterior urethral stricture. No positive history was found in 14 (48.3%) patients for the stricture disease, while six (20.7%) had straddle trauma and nine (31%) had an iatrogenic stricture. All of the patients were pre-operatively investigated and at 3 and 6 months postoperation by uroflowmetry and voiding cystourethrography (VCUG). If there were suspicious voiding symptoms, selective uroflowmetry and VCUG were performed at 12 months postoperation.


RESULTS
The mean operation time was 31.7 min (20-45 min). Twenty-three (79.3%) and 18 (62.1%) patients showed normal urethra on VCUG with improvement of symptoms at 3 and 6 months, respectively. Thus, recurrence was 37.9% after 6 months of follow-up. The mean pre-operative peak urinary flow rate (Qmax) was 6.47 ml/s. The mean postoperative Qmax at 3 and 6 months was 17.17 ml/s and 15.35 ml/s, respectively. The success rate and flowmetry results did not show any statistical significance in relation to site, length and cause of the strictures. The other 11 patients who failed to improve underwent repeated HLU sessions: 4/11 (36.3%) achieved successful outcomes. Among the seven patients with failed HLU for the second time, a third session was conducted. However, only one patient (14.2%) was cured, while open repair was needed for the remaining six.


DISCUSSION
One study has previously been published on the management of pediatric urethral strictures using HLU. The present results are similar to short-term studies after a single session of visual internal urethrotomy using cold knife (VIU). In the present study, the length, location and cause of strictures did not significantly affect the results. However, the outcomes with strictures <1 cm were better than strictures >1 cm, although patients with strictures >2 cm were excluded. In the present study, the success rates among patients with second and third sessions of HLU were 36.3% and 14.2%, respectively. This was similar to other studies, which reported low success rate with the second session of VIU. The present study was limited by the relatively short period of follow-up and the small number of patients. However, it was the first prospective study evaluating HLU for pediatric strictures. The use of flowmetry and VCUG for evaluation of all patients added to the strength of the study.


CONCLUSION
HLU can be safely used with good success rates for the treatment of primary urethral strictures (<2 cm) in children. Repeat HLU (more than twice) adds little to success.