First Prize: Factors Affecting Blood Loss During Percutaneous Nephrolithotomy: Prospective Study

Background and Purpose: Bleeding is a major concern during percutaneous nephrolithotomy (PCNL), especially with the use of multiple tracts. This prospective study aimed to identify factors affecting blood loss during PCNL. Patients and Methods: Data were collected prospectively from 236 patients undergoing 301 PCNL procedures at our institute since June 2002. Blood loss was estimated by the postoperative drop in hemoglobin factored by the quantity of any blood transfusion. Various patient-related and intraoperative factors were assessed for association with total blood loss or blood transfusion requirement using stepwise multivariate regression analysis. Results: The average hemoglobin drop was 1.68 ± 1.23 g/dL. Stepwise multivariate regression analysis showed that the occurrence of operative complications (P < 0.0001), mature nephrostomy tract (P < 0.0001), operative time (P < 0.0001), method of access guidance (fluoroscopy v ultrasound) (P = 0.0001), method of tract dilatation (P = 0.0001), multiple (≥2...