Costly Complications after Kidney Stone Removal

Unplanned hospital visits after kidney stone removal happened often and were very expensive

(RxWiki News) Procedures for kidney stone removal are generally low-risk. However, the procedure itself may not be a patient's biggest concern.

A recent study found that procedures to remove kidney stones often led to costly, unplanned hospital visits due to complications within 30 days of the procedure.

The researchers suggested that these findings should encourage efforts to identify preventable causes of unplanned, post-procedure visits, and come up with interventions to reduce complications of kidney stone surgery.

"Discuss the risk of post-procedure complications with your urologist."

The lead author of this study was Charles D. Scales, Jr., MD, MSHS, from the Division of Urologic Surgery and Duke Clinical Research Institute at Duke University in Durham, North Carolina.

The study included 93,525 patients who underwent a procedure to remove kidney or ureteral stones (stones that have moved from the kidney to the tube between the kidney and the bladder called the ureter) between 2003 and 2011.

All of the participants were enrolled in private insurance for at least one year before the procedure and at least 30 days after the procedure. Everyone was at least 18 years old, with 71 percent of the participants being between the ages of 31 and 55 years old. A total of 58 percent of the participants were male.

The researchers used Marketscan, a database of over 170 million privately insured people in the United States that includes medical records.

Kidney stones affect around one in 11 people in the United States. 

A total of 52 percent of the participants underwent shockwave lithotripsy (SWL), 45 percent underwent ureteroscopy (URS) and 3 percent underwent percutaneous nephrolithotomy (PNL).

SWL is a nonsurgical method of treating kidney and ureteral stones, and is the most common treatment for kidney stones in the United States. SWL involves sending shock waves from outside the body to break up the stones so that they can be passed through urine.

URS is an outpatient procedure in which the doctor inserts a small scope into the bladder and ureter in order to find the stones and physically remove them with a tiny wire basket.

PNL is an inpatient procedure that involves a surgeon entering the kidney through a small cut in the patient's back and removing the stones through a tube using a miniature camera. This procedure is only used in patients with large or irregularly shaped kidney stones, patients with infections and those who have had a failed SWL or who do not qualify for any other procedure.

The findings of this study showed that 12,478 (13 percent) of the participants had an unplanned visit to the emergency department or readmission to the hospital within 30 days of undergoing the procedure. Of these unplanned post-procedure visits, 16 percent were due to pain, 10 percent were due to infection, 2 percent were due to bleeding and 1 percent were due to kidney failure.

Of the participants who underwent SWL, 12 percent returned for an unplanned visit, compared with 15 percent of the URS group and the PNL group.

The researchers found that 71 percent of all unplanned procedures happened in the emergency department. Participants that were readmitted as hospital inpatients were generally older and less healthy overall.

The findings revealed that the participants who underwent SWL had 26 percent decreased odds of having an unplanned visit post-procedure compared to those who underwent PNL. The odds of an unplanned visit following PNL and URS were not statistically different.

The participants who underwent their procedure at a high-volume facility (centers that see more patients than 90 percent of all care centers) were 20 percent less likely to have an unplanned post-procedure visit compared to participants who received treatment at a low-volume facility.

The estimated cost of one unplanned post-procedure visit after PNL was $47,618 and a visit after SWL was estimated to be $32,156. Those costs are compared with only $23,436 for an unplanned visit after URS.

"Our findings provide a good starting point to understand why these complications are happening and how they can be prevented, because the costs to patients who suffer complications and to the health care system are substantial,” Dr. Scales said in a press statement. “Reducing unplanned emergency visits and hospitalizations associated with kidney stone treatments could result in significant cost savings if the causes can be identified and addressed."

The study was limited because the researchers used an insurance database and therefore did not have access to data on the complexity of the intervention and other factors that may be associated with unplanned visits, such as stone size or location.

Also, the researchers did not know if the unplanned visits were all directly related to the procedure — such as visits for pain or infection — or indirectly related — such as those for a heart attack.

This study was published on April 28 in Surgery.

The Robert Wood Johnson Foundation Clinical Scholars program, the US Department of Veterans Affairs, the National Institute of Diabetes and Digestive and Kidney Diseases and the National Library of Medicine provided funding.

Review Date: 
April 28, 2014