Can we predict postoperative fever and urinary tract ınfection after retrograde ıntrarenal surgery? Results of a case...

Postoperative fever (POF)/urinary tract infection (UTI) is one of the most unpleasant and undesirable conditions for surgeons after retrograde intrarenal surgery (RIRS). RIRS is not recommended for any patient with a positive urine culture to avoid POF and UTI, but some patients may develop postoperative UTI even if the urine culture is sterile. This study investigated the predictive factors of fever and UTIs after RIRS.

In total, 1240 patients who underwent RIRS for proximal ureteral stones and/or kidney stones were analyzed. After case-control matching, 168 patients were included in the study. Demographic data, preoperative/peroperative/postoperative data, and hematological parameters were compared. Patients with sterile urine cultures were included in the study. Postoperative fever was defined as fever ≥ 38 °C within 72 h after RIRS. Patients were divided into two groups: those with and without POF/UTI. Demographic data, preoperative and postoperative findings, and inflammatory parameters of the patients were compared retrospectively.

POF/UTI was observed in 61 (36.3%) of 168 patients who underwent RIRS. After case-control matching, increased body mass index (BMI) and longer operation time were found to be significant predictors of POF/UTI (p = 0.001 and 0.016 respectively). Preoperative systemic immune-inflammation index (SII) (PxN/L), high Platelet/Lymphocyte Ratio (PLR), and urine leukocyte positivity were found to be significant predictors of POF/UTI (p = 0.037, 0.025 and 0.038 respectively).

Hematological parameters are simple and feasible to use to evaluate POF/UTI in patients undergoing RIRS. High SII and PLR may predict POF and early infection after RIRS. In addition, according to demographic data and per-operative status, high BMI and prolonged operation time are risk factors for infection.