25.6: Urinary Tract Calculi VI: Surgical Management

Procedures for Kidney Stones

Medical intervention is necessary when kidney stones or renal calculi are too large to pass spontaneously (typically greater than 5 millimeters) when stones are accompanied by symptomatic infection (such as fever or pyelonephritis), when they impair kidney function, or when they cause persistent symptoms like severe pain, nausea, or urinary retention. Additionally, patients with only one kidney or those who cannot be treated with medical management also require intervention.

Endourologic Procedures

Endourologic techniques offer minimally invasive options to remove stones from the bladder, ureters, and kidneys.

• Bladder Stones: Small bladder stones are removed using cystolitholapaxy via cystoscopy. For larger stones, a transurethral or percutaneous suprapubic cystolitholapaxy is performed. In this procedure, ultrasonic, laser, or electrohydraulic energy breaks up the stones, which are then flushed out through bladder irrigation.
• Ureteral or Renal Pelvis Stones: A flexible or rigid ureteroscope is used to access stones in the ureter or renal pelvis. Ureteroscopy can be combined with ultrasonic, laser, or electrohydraulic lithotripsy to fragment the stones before removal.
• Percutaneous Nephrolithotomy (PCNL): For larger renal stones, PCNL is performed by making a small incision in the patient's back and inserting a nephroscope through a sheath into the kidney. With fluoroscopic or ultrasound guidance, the stones are fragmented using ultrasonic, laser, or electrohydraulic energy, and the debris is irrigated out of the kidney.

Lithotripsy

Lithotripsy involves breaking up kidney stones into smaller fragments so they can pass via the urinary tract. It includes techniques like laser lithotripsy and extracorporeal shock wave lithotripsy:

• Laser Lithotripsy: Typically used for ureteral or large bladder stones. A ureteroscope is inserted through the urethra, and a fiber-optic laser (usually a holmium laser) is directed at the stone to fragment it. The fragments are then removed or flushed out. The laser lithotripsy procedure is minimally invasive and usually performed under general anesthesia.
• Extracorporeal Shock Wave Lithotripsy (ESWL): This procedure is preferred for kidney or upper ureter stones smaller than 2 cm. Shock waves generated by a lithotripter are focused on the stone using fluoroscopy or ultrasound guidance. The waves break the stone into smaller fragments, which can then pass naturally through the urine. This procedure is performed under spinal or general anesthesia.

Surgical Therapy

Surgery may be necessary in cases where stones cause severe pain, infection, or obstruction. The type of surgery depends on the stone's location:

• Nephrolithotomy: An incision is made into the kidney to remove the stone.
• Pyelolithotomy: An incision is made into the renal pelvis to remove stones.
• Ureterolithotomy: An incision is made to remove stones located in the ureter.
• Cystotomy: For bladder stones, a cystotomy may be performed to access and remove the stones.