Percutaneous nephrolithotomy (PCNL) is an effective and guideline-recommended surgical technique for the treatment of large and complex renal stones; however, perioperative bleeding remains one of its most significant complications. Reported bleeding and transfusion rates vary widely in the literature, potentially due to differences in surgical technique, surgeon experience, and institutional practices.

This retrospective, single-center study aims to evaluate perioperative and postoperative bleeding outcomes, transfusion requirements, and bleeding-related complications in patients who underwent PCNL performed by a single surgeon. The findings are intended to clarify whether the real-world bleeding risk associated with PCNL is lower than commonly reported.

Percutaneous nephrolithotomy (PCNL) is an effective and guideline-recommended surgical technique for the treatment of large and complex renal stones; however, perioperative bleeding remains one of its most significant complications. Reported bleeding and transfusion rates vary widely in the literature, potentially due to differences in surgical technique, surgeon experience, and institutional practices.

This retrospective, single-center study aims to evaluate perioperative and postoperative bleeding outcomes, transfusion requirements, and bleeding-related complications in patients who underwent PCNL performed by a single surgeon. The findings are intended to clarify whether the real-world bleeding risk associated with PCNL is lower than commonly reported. This is a retrospective, single-center observational study conducted at Elazığ Fethi Sekin City Hospital, Türkiye. Medical records of patients who underwent percutaneous nephrolithotomy between August 1, 2022, and December 20, 2025, will be reviewed retrospectively using the hospital information management system and anesthesia records.

All PCNL procedures were performed by a single experienced urologist using standardized surgical techniques. Demographic characteristics, perioperative variables, laboratory values, bleeding parameters, transfusion requirements, postoperative outcomes, and complications will be analyzed. Surgical complications will be classified according to the Clavien-Dindo classification system.

Inclusion Criteria:

• Patients who underwent percutaneous nephrolithotomy (PCNL)
• Availability of complete intraoperative and postoperative follow-up data
• Availability of preoperative and postoperative complete blood count and biochemical laboratory results

Exclusion Criteria:

• Pregnancy
• Conversion to open or laparoscopic surgery during PCNL
• Simultaneous additional surgical procedures, bilateral or synchronous bilateral PCNL
• Known coagulation disorders, hematological diseases, or active bleeding in the preoperative period
• Use of anticoagulant or antiplatelet therapy without appropriate perioperative management
• Preoperative blood transfusion requirement
• Severe intraoperative hemodynamic instability affecting the surgical course
• Missing hemoglobin or hematocrit data, insufficient transfusion or complication records
• Inadequate postoperative follow-up or transfer to another institutionConversion to open or laparoscopic surgery during PCNL
• Simultaneous additional surgical procedures, bilateral or synchronous bilateral PCNL
• Known coagulation disorders, hematological diseases, or active bleeding in the preoperative period
• Use of anticoagulant or antiplatelet therapy without appropriate perioperative management
• Preoperative blood transfusion requirement
• Severe intraoperative hemodynamic instability affecting the surgical course
• Missing hemoglobin or hematocrit data, insufficient transfusion or complication records
• Inadequate postoperative follow-up or transfer to another institution

Patients diagnosed with nephrolithiasis who underwent percutaneous nephrolithotomy at a single tertiary care center. The study population consists of adult patients treated by a single surgeon, with perioperative and postoperative outcomes evaluated retrospectively.