There is a widespread perception that urinary stones that are large or located deep within the kidney inevitably require high-risk surgery. However, recent clinical findings are challenging that assumption. At the 45th International Congress of the Société Internationale d'Urologie (SIU 2025), held in Edinburgh, United Kingdom, the results of an analysis of 165 ureteroscopy and flexible ureteroscopy procedures performed at Goldman Urology Clinic Jamsil Branch were presented, drawing attention for contradicting conventional expectations.
Urinary stones are commonly categorized by difficulty according to their size and location. In general, stones larger than 10 mm or those located in the upper ureter or inside the kidney are considered complex stones. Because of this classification, many patients assume that larger or deeper stones inevitably require more dangerous surgical procedures.
However, the 165 surgical cases analyzed in this study included a wide range of stones, from small stones measuring about 3 mm to relatively large stones up to 25 mm. The cases also involved stones located not only in the lower ureter but also in the upper ureter and within the kidney. Despite this variation, every procedure was successfully completed. Moreover, no major complications were reported. Some patients experienced mild reactions such as temporary pain or minimal bleeding, but these were minor and resolved within a short period with appropriate management.
These findings clearly indicate that the size and location of a stone alone do not necessarily determine the level of risk. In fact, the more critical factor in stone treatment is not simply which stone is removed, but how the surgeon approaches it and what strategy is used to fragment and remove it. Even when stones are similar in size or location, the level of difficulty and procedural safety can vary greatly depending on the surgical approach and treatment strategy.
Another common misconception among patients undergoing complex stone surgery concerns the type of anesthesia used. Many people believe that when stones are large or located deep inside the kidney, general anesthesia is unavoidable. In clinical practice, however, this is not always the case. Most of the URS (ureteroscopy) and RIRS (retrograde intrarenal surgery) procedures presented at the conference were performed under spinal anesthesia or local anesthesia at Goldman Urology Clinic. These approaches reduce the cardiopulmonary burden associated with general anesthesia, allow faster recovery, and can shorten hospital stays. For elderly patients or those with underlying cardiovascular or respiratory conditions, avoiding general anesthesia can be particularly beneficial from a safety perspective.
Therefore, even when stones are large, general anesthesia is not necessarily required. Instead, the most appropriate anesthetic method should be selected after comprehensively considering factors such as the location of the stone, the patient’s overall health condition, and the ability to manage pain during the procedure.
In endoscopic urinary stone surgery, the surgeon’s level of experience is extremely important. Although the procedure may appear standardized externally, the actual operation involves a continuous series of clinical decisions. Surgeons must determine which access sheath to use, how to adjust laser energy based on the stone’s hardness and structure, whether to pulverize the stone into fine particles (dusting) or divide it into removable fragments, and how to maintain stable intrarenal pressure while securing clear visualization during surgery. They must also respond appropriately to unexpected variables such as bleeding, reduced visibility, or stone migration during the operation. These decisions can significantly influence both the safety and the final outcome of the procedure.
Urinary stones not only cause severe pain but can also lead to ureteral obstruction, infection, and deterioration of kidney function if left untreated for a prolonged period. For this reason, urinary stone surgery should not be evaluated solely based on the size of a hospital or the sophistication of its equipment. Rather, treatment success largely depends on how much clinical experience the physician has accumulated, how many different types of stones and clinical situations they have personally managed, and how strong their clinical judgment has become through that experience.
Dr. Na Jun-chae of Goldman Urology Clinic Jamsil Branch emphasized that these accumulated clinical experiences and decision-making abilities ultimately determine the success and safety of urinary stone surgery.