Urinary stones refer to all types of calculi that form within the urinary system. Although they are commonly known to originate in the kidneys, the stones can move through the ureters, bladder, and urethra, obstructing the flow of urine and causing pain in surrounding areas. During this process, complications such as urinary tract infection, hydronephrosis, and even kidney failure may occur.
When urinary stones are diagnosed, extracorporeal shock wave lithotripsy (ESWL) is usually considered first. ESWL does not require hospitalization or anesthesia, and patients can typically return to daily activities within about an hour after the procedure. However, not all stones can be treated successfully with ESWL. Situations such as kidney failure, hydronephrosis, or urinary tract infection may require different treatment approaches.
When kidney function is impaired and kidney failure develops, endoscopic surgery should be considered. ESWL works by breaking the stone into fragments with shock waves so that they can pass naturally through urine. However, if kidney function is already compromised, urine flow may be insufficient, making natural passage of the stone fragments difficult.
In cases where urinary tract infection is present, it is often preferable to remove the stone completely in a single procedure before the inflammation worsens. In such situations, ureteroscopic stone removal may be more effective than ESWL.
Certain special types of stones also require ureteroscopic treatment. These include radiolucent stones, bilateral ureteral stones, and multiple stones. Radiolucent stones cannot be detected on X-ray imaging, making ESWL—which relies on X-ray guidance—difficult to perform. Bilateral ureteral stones that block both ureters simultaneously can prevent urine from draining from either kidney, creating a dangerous situation that may lead to acute kidney failure. In such cases, waiting for multiple sessions of shock wave lithotripsy may not be feasible.
Additionally, when multiple stones are present in one ureter, fragmenting only one stone may not resolve the obstruction because other stones remain. For this reason, ureteroscopic stone removal is often a more appropriate treatment option than ESWL in these cases.
When the stone is larger than 1 cm, endoscopic surgery may also be the more effective treatment from the beginning. Large stones greater than 1 cm have a relatively low probability of being completely fragmented with a single ESWL session, meaning several treatments may be required. Because ESWL sessions must typically be spaced about five to seven days apart to minimize physical stress, the overall treatment period can become prolonged. Meanwhile, the large stone may continue to obstruct the ureter, causing persistent severe pain and further decline in kidney function. In these cases, removing the stone in a single procedure through endoscopic surgery can be faster and more effective.
Dr. Kim Byung-hoon of Goldman Urology Clinic’s Incheon branch explained that urinary stones can cause pain comparable to childbirth and are therefore extremely distressing for patients. He noted that if ESWL does not produce sufficient results, ureteroscopic stone removal—which can eliminate the stone in a single procedure—should be considered. He also added that advances in surgical equipment, including rigid and flexible endoscopes, now allow these procedures to be performed more safely and effectively.