Although most patients can spontaneously expel a kidney stone, nearly 10-20% of adults will ultimately need some type of operative procedure. Here, I’ll discuss common complications of kidney stone surgery that could become a source of medical-legal liability.
Surgical Procedures
Three types of surgical procedures are commonly used to treat kidney stones, depending on size and complexity—external shock-wave lithotripsy (SWL), ureteroscopy with laser lithotripsy and/or basket retrieval (URS), and percutaneous nephrolithotomy (PCNL). SWL and URS are usually performed on small to medium-sized stones while PCNL is typically reserved for large, complex stones.
SWL involves external shockwaves pulverizing a stone under x-ray and/or ultrasonic guidance. The stone fragments are then expelled down the ureter (the drainage tube connecting the kidney to the bladder) and fragments are urinated out. URS involves placing a small scope into the ureter (passed retrograde, first into the bladder and then into the ureter) and fragmenting the stone into passable pieces with a laser, and/or grasping pieces of stone with small baskets and removing them. Last, PCNL involves accessing the kidney through a 1-cm hole in the patient’s back and either removing stones intact or pulverizing them with a combination of instruments.
Common Complications
A recent review of 25 closed malpractice claims in the state of New York involving kidney stone management, between the years 2005 and 2010, provides guidance on legal liability. The most common complications in this series included injury to the ureter, such as ureteral perforation and avulsion, retained or forgotten ureteral stent, and sepsis. Out of 25 claims, only two involved SWL. Each technique has its own potential complications, however, hemorrhage and infection are risks of all of these approaches.
The most serious complication of ureteroscopy involves perforation of the ureter, which occurs in a low single-digit percentage of uncomplicated cases. However, it is more common in complex cases, such as when the anatomy is aberrant or when the patient’s stone is impacted or densely adherent to the ureter. Most cases of ureteral perforation, if identified and appropriately treated, will heal without long-term ill-effects such as scarring or stricture of the ureter. Appropriate management includes identifying the perforation, aborting the procedure once the perforation is identified, and placing a ureteral stent and/or percutaneous nephrostomy tube to divert urine from the site of perforation so the ureter can heal.
Perforated ureters require several weeks to heal. Moreover, the patient’s stone must then be definitively managed after healing. During follow-up of a perforation, the urologist must be vigilant to prevent scarring of the area perforation, which can lead to a ureteral stricture.
For cases in which a perforation occurred, routine imaging after stent removal is critical. Either a renal ultrasound or CT scan should be obtained shortly after ureteral stent or nephrostomy tube removal to ensure appropriate healing and drainage of the affected kidney. Any symptoms after stent or nephrostomy tube removal—such as flank pain, nausea, vomiting, or blood in the urine—should be promptly investigated with appropriate imaging to ensure the kidney is not obstructed.
Ureteral Stent Removal
In the vast majority of endoscopic kidney stone procedures, ureteral stents are left in the ureter to both prevent obstruction of the kidney and facilitate passage of fragments of stone. It is imperative that the urologist explains to the patient that these devices are temporary and must be removed within a reasonable timeframe after surgery—usually a few weeks to a month.
Appropriate follow-up for removal is especially critical during emergency procedures and/or when patients are traveling and a stent is placed by a urologist far from the patient’s normal medical providers. Many urologists and institutions use stent tracking software systems to ensure these devices are removed.
As with all surgical procedures, close attention to appropriate antibiotic prophylaxis is very important in kidney stone surgery. It is important that urologists assess the appropriate perioperative antibiotics based on local resistance patterns, patient factors, and results of previous urine cultures. Additionally, obtaining samples of urine from the bladder, kidney and, if possible, an indwelling stent or nephrostomy tube (if one is present) at the time of surgery can assist in the management of post-op infections.
Operations for kidney stones comprise a significant portion of urologic practice and are thus a common cause of medical liability legal action. The urologist should identify and treat a handful of serious complications when performing kidney stone surgery. Of particular interest are retained ureteral stents, perforation of the ureter, and infectious complications of urinary stone surgery.
