Micropercutaneous Laser Lithotripsy: How to Improve Stone Free Rate

Introduction: Micropercutaneous Nephrolithotomy is a novel technique with the creation of a 4.85-8F working channel. The advantage of micro-PCNL is the possibility of kidney puncture under direct endoscopic control. Materials and Methods: 99 patients aged 47,3 ± 16.9 years were included in the study. 78 patients had isolated kidney stones (78.8%). The stone size ranged from 8 to 38 mm (13.9 ± 5.4 mm). Group A included stones smaller than 15 mm (57 patients, 57,6%) and Group B included stones larger than 15 mm (42 patients, 42,4%). A 4.85 F percutaneous sheath was used in 38 (38,4%) patients, 8 F sheath was used in 61 (61,6%) patients. A holmium laser for lithotripsy was used in 46.5% cases, the thulium fiber laser in 53.5%. Results: The average surgery time was 39,9 ± 13.7 min (from 13 to 75 min). A stone-free rate (SFR) for patients of both groups was 88.8%. A Double-J stent was placed in 39 (39.4%) patients. In one case conversion to the mini-PCNL was done. In four cases (4%) retrograde stone manipulations were performed through ureteral access sheath. 5 (5.1%) patients required the second micro-PCNL tract. 3 (3%) patients required stenting postoperatively. In 7.1% of cases the episode of acute pyelonephritis developed. In 7 cases (7,1%), Extracorporeal Shock Wave Lithotripsy was required due to residual stones. Conclusions: We recommend using the laser micro-PCNL for the category of patients with severe comorbidities, including coagulopathy. The micro-PCNL could be safely performed in patients with kidney stones larger than 1.5 cm.