Background: Vapor Tunnel (VT) technology is the result of a pulse modulation during holmium laser emission which reduces stone retropulsion. We present the outcomes of this tool in the treatment of ureteral stones.
Methods: Two hundred ten patients with a ureteral stone were randomly assigned to holmium laser lithotripsy with (group A) or without (group B) the VT technology. The 35 W LithoEVO laser generator (Quanta System, Samarate, Varese, Italy) was used. We compared operative time, dusting time, delivered energy, retreatment rate due to stone push-up, ureteral lesions, and stone-free rate (SFR) and postoperative strictures at 1 month. We also compared outcomes according to stone position.
Results: VT technology was associated with significantly lower mean operative time (25.7 vs. 37.2 min), dusting time (9.7 vs. 15.3 min), delivered energy (7.7 vs. 19.9 KJ). In group B 9 patients (8.5%) were retreated due to stone push-up (P=0.01) for a proximal or middle stone, 6 (5.7%) postoperative strictures occurred (P=0.03) and a higher ureteral lesion rate was observed (7.6% vs 35.2%, P=0.04). 1-month SFR was comparable (93.4% vs. 88.6%, P=0.11). Postoperative complication rate was higher in group B (P=0.05). Without VT technology, ureteral lesions and strictures rates were significantly higher independently from stone position.
Conclusions: The VT technology is associated with significantly lower operative and dusting time independently from stone position, due to a reduced retropulsion, which makes treatment quicker and easier. It also avoids stone push-up especially for proximal and middle stones and reduces ureteral lesions, postoperative complications, and ureteral strictures.