Role of dusting and pop-dusting' using a high-powered (100W) laser machine in the treatment of large stones (≥15mm): prospective outcomes over 16months

Ureteroscopy and laser stone fragmentation (URSL) has had recent advancements with the more powerful laser systems with the ability to dust' and pop-dust' the stone. We wanted to look at the outcomes of this method for large stones (>= 15mm) using our new 100W holmium laser. Over a period of 16months (January 2017-April 2018), 50 patients underwent URSL for minimum cumulative stone size of >= 15mm. Data were collected prospectively on patient and stone demographics and outcomes of URSL. The laser setting used was a power of 0.3-0.6J and a frequency of 20-50Hz using a long-pulse setting with a 272-mu m fiber. Fifty patients underwent 55 URSL procedures (5 bilateral procedures) using dusting and pop-dusting settings. The mean age was 58years (range 2-88years) with a male:female ratio of 35:15. The mean single and overall stone size were 10.3mm (3-23mm) and 21mm (range 15-52mm) with two-thirds of all patients (65%) having multiple stones. The stone location was in the kidney (n=65, 78%), in the ureter (n=19, 22%) and 5 patients had bilateral renal stones. With a mean operating time of 51min, the initial and final SFR were 93 and 98%, respectively. A pre-operative stent, access sheath and a post-operative stent were present in 29 (53%), 34 (62%) and 51 (93%) procedures, respectively. Over a mean hospital stay of 0.6days (74% day-case procedures), there was one Clavien IV complication related to urosepsis but without any other major or minor complications. Dusting and pop-dusting techniques achieve an excellent SFR with low risk of complications even for large stones. This might set a new benchmark for treating large stones, bilateral or multiple stones in a single setting, without the need for secondary procedures in most cases.