Introduction
Since retrograde intrarenal surgery (RIRS) was first defined in the 1990s, there have been improvements concerning this technique [1,2]. With the development of flexible endoscopes (miniaturization of endoscopes and improvement in image quality), increase in the quality of light sources, and advances in the lithotripsy technology, RIRS has become the first treatment option for upper urinary tract stones of <2 cm [3,4]. In parallel to these developments, the treatment of proximal ureteral and renal stones has undergone a significant change in recent years. In a systemic review, the total stone-free rate was reported as 91% and the major complication rate (Clavien ≥3) as 4.5% in an average of 1.45 procedures in patients who underwent RIRS due to having renal stones of >2 cm [5,6]. Although there are large series in the literature investigating the complications of semirigid ureteroscopy [7,8], only a limited number of studies have been conducted to evaluate RIRS complications in large series. Some scoring systems have been defined for grading surgical complications. Among these, the modified Clavien classification system (MCCS) is most commonly used for postoperative complications, and the modified Satava classification system (SCS) is employed to classify intraoperative complications and events [9,10]. Complication classification systems are important because they can easily demonstrate the safety of the surgery and also create standardization to compare results obtained from different centers. In addition, determining parameters associated with complications and predicting complication development are as important as achieving stone-free status, which is considered to indicate the success of surgery.
In this study, we aimed to classify intraoperative and postoperative complications in patients undergoing RIRS using MCCS and SCS and to evaluate complication-related parameters.