Abu Dhabi, United Arab Emirates (UroToday.com) Dr. Alexey Martov demonstrates a video presentation on the use of thulium laser technology for mini-percutaneous nephrolithotomy (PCNL). He presented his experience where they examined the efficacy of minimally invasive percutaneous nephrolithotomy (micro-PCNL), a novel operative technique that uses 4.85-8F access sheathes for renal access. Dr. Martov started his presentation mentioning that the distinct advantage of micro-PCNLs over more traditional mini-PCNLs and ultra-mini-PCNLs is that it minimizes the chance for chance of puncturing the kidney during renal access during x-ray, ultrasound, and even endoscopic control, which significantly reduces the risk of potentially damaging large vessels and neighboring structures during procedures. The aim of his study was to thoroughly analyze the efficacy, efficiency, and relative safety of micro-PCNLs and to determine its potential to change the current treatment of larger kidney stones. 

Dr. Martov reported his experience with total of 99 patients. The overall stone-free rate (SFR) after one-session of micro-PCNL was 88.8% (Group A: 91.2% and Group B: 85.7%). If patients’ stones were not removed after deployment of the first percutaneous tract, as was the case with 4 patients, retrograde stone manipulations via a flexible ureteroscope and nitinol baskets were made through the ureteral access sheath (UAS). 5 (5.1%) patients with multiple kidney stones required a secondary micro-PCNL to improve lithotripsy conditions while 3 (3%) patients required additional stenting due to renal colic caused by the migration of stones into the ureter after micro-PCNL. Bleeding in all cases was extremely negligible. In 7.1% of cases, acute pyelonephritis was developed and was treated conservatively. In another 7 cases (7.1%), ESWL was required due to the presence of residual stones one month following the PCNL. 

In conclusion, due to the high efficiency and low complication rate associated with laser micro-PCNL, this method of stone removal is ideal for those patients who suffer from severe concomitant diseases, including coagulopathy. The placing of a 10/12F ureteral access sheath greatly contributes to the passive flushing of fragments during lithotripsy, which, together with the use of the 8F percutaneous sheath, makes it possible to effectively and safely perform micro-PCNL in patients with kidney stones larger than 15mm.

Presented by: Alexey Martov, MD, PhD, Head of Urology Department, Federal Medical-Biological Agency of Russian Federation State Institute of Continuous Medical Education, Division of Urology, Moscow, Russia

Written by Zhamshid Okhunov, MD, Department of Urology, University of California, Irvine, at the 37th World Congress of Endourology (WCE) – October 29th-November 2nd, Abu Dhabi, United Arab Emirates