What is the optimum lithotripsy method for high density stones during mini-PNL? Laser, ballistic or combination of both.

Abstract

Percutaneous nephrolithotomy (PNL) is the primary treatment option for renal stones > 20mm in diameter. Mini-PNL gained popularity with its minimally invasive nature. The aim of this study was to compare the efficiency of ballistic and laser lithotripsy with the combined use of both techniques. Data of 312 patients underwent mini-PNL for renal stones with Hounsfield Unit > 1000 was investigated retrospectively. We identified 104 patients underwent combined ballistic and laser lithotripsy. Propensity score technique was used to create the laser and ballistic lithotripsy groups. Groups were matched on stone size, stone density, and Guy's stone score. Primary end point of the study was to compare the stone free rate (SFR), complication rates, and duration of surgery. Mean age of the population was 49.4 ± 6.1, stone size was 24.6 ± 6.3mm, and stone density was 1215 ± 89 HU. The groups were similar for age, stone size, stone density, and Guy's stone score. The SFR and the complication rates of the 3 groups were similar (p = 0.67). The duration of the surgery was shorter in the combined group (46.1 ± 6.3min) compared to the laser lithotripsy (54.5 ± 6.6min) and ballistic lithotripsy (57.2 ± 6.9min) groups. Both laser and ballistic lithotripsy are effective methods for stone fragmentation during mini-PNL. Combined use of both methods has the potential to improve the fragmentation rates and diminish the operative times in case of high density stones.