Our Experience With Retrograde Intrarenal Surgery for Nephrolithiasis

Abstract

Introduction: Retrograde intrarenal surgery (RIRS) alongside percutaneous surgery is gaining a leading position in the nephrolithiasis treatment. According to 2022 EAU Guidelines, RIRS is one of the basic surgical modalities to treat 10-20 mm kidney concrements. Turning concrements into dust, holmium laser is the most effective and safest method for concrement disintegration.Objective: To determine surgical possibilities of holmium laser lithotripsy for single and multiple unilateral nephrolithiasis using disposable flexible ureterorenoscopes.Materials and methods: We performed 124 interventions from October 2021 to October 2022 using LithoVue flexible ureterorenoscope in patients with nephrolithiasis, of them 70 males and 54 females with the mean age being 54 (27–74) years. Patients were divided into 2 groups: group I (56 patients) with a single renal concrement, group II (68 patients) with multiple concrements (2 to 7 pieces). The concrement size ranged from 5 to 20 mm. The density of kidney concrements on computed tomography (CT) was 214 to 1,620 HU. LightTrail 230 μm and 270 μm reusable laser fibers were chosen for Auriga XL holmium laser crushing mode. Laser operating settings were as follows: frequency 8 Hz, pulse energy 1,200 mJ (LightTrail 230 µm) and frequency 12 Hz, pulse energy 1,800 mJ (LightTrail 270 µm). These are the maximum setting values for the specific laser fibers.Results: Average time of 1 concrement disintegration (V = 1 cm3) was 28.3 minutes. Concrement disintegration time was 21.4 ± 6.7 minutes (group I) and 42.3 ± 9.4 minutes (group II). Intervention time was 27.4 ± 8.3 minutes (group I) and 54.6 ± 12.4 minutes (group II). In-hospital stay was 2.5 ± 1 days (group I) and 3 ± 1 days (group II). The rate of surgical success according to CT scans was 92.6% (group I) and 88.2% (group II). Two patients in group I and 5 patients in group II required reintervention. One patient (1.8%) in group I and 3 patients (4.4%) in group II developed an acute pyelonephritis (Clavien-Dindo classification, grade II). In the remaining patients the complications did not exceed Clavien-Dindo grade I. There were no equipment-related issues in the perioperative period.Conclusions: As a safe and effective procedure with low complication rate, fast postoperative recovery, and short hospital stay, RIRS can be used as a method of choice for disintegration of kidney concrements up to 20 mm in size.

Keywords

• retrograde intrarenal surgery
• concrement
• holmium laser
• ureterorenoscope
• laser fibers