Comparative analysis of holmium: YAG laser internal urethrotomy versus Cold-Knife optical internal urethrotomy in the management of urethral stricture - a systematic review and meta-analysis

Objective: Urethral stricture management has posed enduring challenges in urology, demanding innovative and effective treatment modalities. This study addresses the persistent issues associated with urethral strictures, focusing on the comparative evaluation of two contemporary treatment modalities: Ho: YAG Laser Internal Urethrotomy (HIU) and Cold Knife Optical Internal Urethrotomy (CIU). Methods: A comprehensive search of PubMed, Embase, Web of Science, Cochrane Library, and ResearchGate was conducted to identify relevant studies up to November 2023. Inclusion criteria encompassed comparative studies evaluating HIU and CIU in patients with urethral stricture. Data extraction, quality assessment, and subgroup analyses were performed using standardized methods. Outcome measures included preoperative and postoperative mean the maximum urine flow rate (Qmax), mean surgical time, recurrence rates, and perioperative complications. Results: Nine articles met the inclusion criteria, and their data were analyzed using RevMan 5.4.1. Forest plots were generated for preoperative and postoperative mean Qmax, mean surgical time, recurrence rates, and perioperative complications. While postoperative mean Qmax (MD -0.06; 95% CI: -0.28-0.16; P=0.60, I-2=75%) and mean surgical time (MD 2.16; 95% CI: -1.66-5.99; P=0.27, I-2=98%) showed no significant differences between HIU and CIU, a trend towards lower recurrence rates (RR 0.71; 95% CI: 0.48-1.06; P=0.09, I-2=46%) was observed with HIU but without statistical significance. Perioperative complications, particularly bleeding (RR 0.21; 95% CI: 0.08-0.53; P=0.001, I-2=0%), favored HIU over CIU. The subanalysis indicates that for the treatment of complex urethral strictures, the two surgical methods differ in terms of mean Qmax at 6 months postoperatively (MD -2.51; 95% CI: -4.10--0.91; P=0.002, I-2=59%) and 12 months postoperatively (MD 2.62; 95% CI: 0.93-4.30; P=0.002, I-2=0%). The HIU group shows a significant decrease in recurrence rate at 12 months postoperatively (RR 0.44; 95% CI: 0.21-0.92; P=0.03, I-2=0%). For short-segment urethral strictures with a length <= 1.5 cm, CIU had a shorter operative time compared to the HIU (MD 4.49; 95% CI: 3.87-5.10; P<0.00001, I-2=44%). Conclusion: Overall, both interventions demonstrated similar efficacy in improving postoperative mean Qmax, mean surgical time, and recurrence rates. However, subanalysis indicates that in the short-term, CIU is more effective than HIU in improving Qmax after complex urethral stricture surgery. In long-term Qmax follow-up after surgery, HIU is significantly higher than CIU, and HIU has a low recurrence rate. In addition, for short-segment urethral stricture (<= 1.5 cm), CIU requires less time. In terms of complications, HIU has a lower risk of bleeding.