A multi-institutional experience of Micro-percutaneous Nephrolithotomy (MicroPERC) for renal stones: Results and feasibility of day case surgery

Purpose To report the multi-institutional outcomes of Microperc for nephrolithiasis and to assess its feasibility in outpatient care. Methods We retrospectively identified all adult patients who underwent Microperc for renal stones at three centres between May 2015 and March 2021. Interventions were performed by three Surgeons. One Surgeon adopted a “one-way” strategy and all Microperc were performed on an outpatient basis, while the other two Surgeons provided inpatient monitoring for at least one day after surgery. The primary endpoint was same-day discharge after Microperc without emergency department visits or unplanned readmission within 30 days of the procedure. The secondary endpoints included treatment outcomes and the 30-day complication rate. Results Out of 72 consecutive patients included, 32 patients (44.4%) had same-day discharge. Median Charlson score (1 [0–2]) and cumulative stone size (15 [12–20] mm) were comparable between both groups. At one month post procedure, 32 patients (44.4%) were stone free and 23 patients (32%) had residual micro-fragments<3mm, conferring an overall success rate of 76.4% (inpatient Microperc group: 77.5% vs outpatient Microperc group: 75%, P=1). Analysis of the 30-day complication rate showed similar results between the two groups (Clavien I-II: 18.1%, Clavien≥III: 4.1%). After outpatient care, the rate of immediate admission and unplanned readmission was 12.5% (n=4), mainly due to urinary tract infection. Conclusion In this multi-institutional study, we report that outpatient Microperc is feasible in selected patients with no significant impact on postoperative outcome. Level of evidence 3