Standardization of retrograde intrarenal surgery with "gravity irrigation" technique leads to low postoperative infection rate regardless of surgeon experience.

OBJECTIVES

We aimed to evaluate the prevalence and predictive factors of postoperative infections after a standardized low-pressure RIRS technique. The secondary outcome was comparing surgeons' experience in terms of infective complication and stone-free rate.

METHODS

A single-center retrospective analysis was conducted on all patients who underwent RIRS for kidney stones between January 2018 and February 2019.

INCLUSION CRITERIA: adults, stone ≤ 20 mm (unless percutaneous nephrolithotomy contraindica-tions). Concomitant ureteral lithotripsy was allowed.

EXCLUSION CRITERIA: bilateral surgery, active urinary tract infections (UTI), pregnancy, fever at surgery. Low-pressure RIRS and ureteroscopy was achieved with gravity irrigation, a 5 Ch open-ended urethral catheter (ureteral lithotripsy), intravenous furosemide (20 mg), and ureteral access sheath above the ureteral-pelvic junction (RIRS).

RESULTS

236 patients were included in the analysis. Mean age was 55.89±13.96 years. Mean stone diameter was 14.28±5.81mm. 43 (18.2%) patients underwent concomitant ureteral lithotripsy. Mean operative time was 61.10 ± 31.36 minutes. Infective complications occurred in 13 (5.5%) patients. Sepsis occurred in 10 (4.2%) patients and septic shock occurred in 1 (0.4%). One patient (0.4%) required stent substitution. Multivariate logistic regression analysis showed that history of UTI predicted for higher risk of postoperative infections (OR 8.434, CI 95% 2.36-29.46). Outcomes comparison of surgical expertise did not statistically differ in terms of stone-free rate and infective complications.

CONCLUSION

Our standardized RIRS technique achieved a low postoperative infective complication rate. History of UTI was the strongest predictor of postoperative infections.