One in seven kidney stone patients end up back in the hospital

At some point in their life, about 27 million people – 8.8 percent of the population – will have the unpleasant experience of passing a kidney stone.

That makes the removal of a kidney stone one of the most basic, most common procedures in the United States – not the type of thing that you’d think would land you in the emergency room a few weeks later.

Except it turns out that, after the extremely routine surgery, one in seven patients actually do make an unexpected trip back to the doctor – and that can cost upwards of $30,000.

“We’ve gotten really good at the surgical removal of kidney stones and the vast majority of people go home the same day,” says Charles Scales, a urologist at Duke University, who has been studying unplanned care after kidney stone removals. “But no one had really looked at the question of what happens afterwards.”

That’s what Scales’ new research, published Monday in the journal Surgery, did. Scales looked at a data set of 93,000 people who had had kidney stones removed or fragmented. He found that 14 percent had an unplanned trip back to the doctor within a month of their kidney stone procedure, where they either turned up at the emergency room or hospital admission.

What surprised Scales the most wasn’t necessarily the rate of unplanned care, but how much those unexpected visits cost. The average cost of an unplanned follow-up visit is just about $30,000 – and sometimes upwards of $45,000.

One of the lingering questions from the study is how many of these unplanned visits are preventable – whether people are turning up at the emergency room because of mistake by their doctor, or if kidney stone removal is just that difficult to perform without these types of follow-up visits.

Scales, for his part, thinks a good number might be preventable. He points to the fact that people seen at really high volume facilities – places that do lots of kidney stone removals – tend to have 20 percent fewer unplanned follow-up visits than people seen at places that do fewer procedures. That suggests having some kind of expertise in the procedure can lead to better outcomes.