Comparison of mini PCNL versus supermini PCNL: a cohort study

Introduction. Over the past 20 years mini-percutaneous nephrolithotomy (mini-PCNL) is remaining an effective method non inferior to standard PCNL with lower rates of serious complication related to bigger nephrotomy tract size like bleeding. However, in comparison to standard PCNL miniPCNL diminishes visualization, leads to increase of intrarenal pressure (IRP), difficulties in stone fragments evacuation, and longer operative time. In 2016 Zeng has developed an innovative aspiration sheath. Novel modification of miniPCNL with suction was called superminiPCNL (SMP) [1]. We have modified this aspiration sheath. There is the lack of data regarding efficacy and safety of this innovative method. Objectives. The aim of the study is to compare efficacy and safety of miniPCNL with SMP using an innovative suction sheath in the treatment of kidney stone disease. Material and methods. Between September 2021 and March 2023, 140 underwent PCNL. Patient were divided into 2 groups 1:1, 70 patients in each group. MiniPCNL was used in control group, SMP using aspiration suction sheath – in intervention group. Operative time, stone-free rate (SFR), bleeding, postoperative complications were compared between two groups. Results. SFR didn`t significantly differ between the groups and was 91.3% and 98.4% respectively (p = 0.117). Mean operative time was less in SMP group with a mean shortening of the procedural time of 13 min (p < 0.001). Hemoglobin drop was comparable between the groups (p = 0.73). Fever was significantly less frequent in SMP group, 11.6% in miniPCNL vs. 1.6% in SMP group (p = 0.042). There were no serious complications (Clavien III and IV) in any group. Discussion. PSMP is not inferior to miniPCNL in terms of efficy and safety. Moreover, it leads to shorter operative ime, decreases complication rates, and thus is a preferable method of renal stone treatment. Keywords: Kidney stone disease, percutaneous nephrolithotomy, surgery, supermini-PCNL.