Pre-Operative Parameters Predicting Hemoglobin Decline Related to Percutaneous Nephrolithotomy

OBJECTIVES: Percutaneous nephrolithotomy (PNL) for upper urinary tract stones is a minimally invasive, effective treatment modality. Despite its high success rates, its potential complications pose a risk. In this study, we aimed to determine the risk factors associated with bleeding which is one of PNL’s most important complications. METHODS: The data of patients who underwent PNL between January 2017 and December 2018 were retrospectively analyzed. The median reduction in post-operative hemoglobin levels compared to preoperative levels was found to be 1.6 g/dl, which was accepted as the threshold value. The patients with hemoglobin decrease above the threshold were assigned as Group 1, and below the threshold as Group 2. Pre-operative, perioperative data, and stone characteristics of the patients were recorded. RESULTS: 169 patients, 85 patients in Group 1 and 84 patients in Group 2 were included in the study. The mean age of Group 1 was significantly higher (47.4±7.9 and 32±9.4 years, respectively, p=0.001) Sixteen in Group 1 (18.8%) and six in Group 2 (7, 1%) had a diagnosis of hypertension (HT) and a significant difference was found (p=0.038). The average stone burden was 2733±1121.3 mm3 in Group 1, and 2326.5±975.6 mm(3) in Group 2. It was observed that there was a significantly higher stone burden in Group 1 (p=0.001). There was a significant difference between the groups in terms of mean operation time (84.4±7 and 76.2±9.9 min, respectively, p<0.001). When the complication rates were analyzed, complications were observed in 25 (29.4%) patients in Group 1 and 12 (14.2%) patients in Group 2, and a significant difference was found between both groups (p=0.019). Age and HT were found to be significant independent risk factors associated with hemoglobin decline in multivariate analyzes (p<0.001 and p<0.027, respectively). CONCLUSION: In this study; advanced age, presence of HT, and high stone burden were found to be predictive of reductions in hemoglobin levels. Furthermore, a correlation of decreased hemoglobin levels was detected with operative times and occurrence of complications.