Model predicts risk for acute gallbladder attack, need for elective cholecystectomy

A new prognostic model accurately predicted risk of emergent gallstone-related hospitalization in older patients presenting with symptomatic gallstones, according to study results.

More than half of people aged 70 years and older experience gallstones. Moreover, gallbladder disease is the most common cause of acute abdominal pain in older patients, accounting for one-third of abdominal operations in patients aged 65 years and older, according to researchers at the University of Texas Medical Branch at Galveston.

These patients are at increased risk for complications such as pancreatitis, blockage of the bile duct and infection in the gallbladder. Although national guidelines recommend for patients with gallstones to undergo cholecystectomy (removal of the gallbladder) the majority of elderly patients do not undergo the procedure.

“There are likely many reasons why people who have symptoms from gallstones do not undergo cholecystectomy,” Taylor S. Riall, MD, PhD, FACS, professor of surgery at the University of Texas Medical Branch at Galveston, told Healio.com/Internal Medicine. “The possible reasons include patient preference such as fear of surgery, poor patient understanding of the risks and benefits of the operation. Patients may not be referred to surgeons for evaluation after a gallbladder attack due to a lack of physician knowledge on when to refer patients, patients may be too unhealthy to tolerate the procedure, or they may lack insurance and access to care.”

PREOP-Gallstones

There are no non-surgical treatments that can make the gallstones go away or prevent future attacks, according to Riall.

“Changing to a low-fat diet may decrease symptoms and some medications dissolve gallstones, but they are expensive, one needs to be on them forever, and they are not effective in the case of large or multiple stones,” she said.

Riall and colleagues developed a predictive model dubbed Predicting Risk of Complications in Older Patients with Gallstones (PREOP-Gallstones) for determining patients at most risk for an acute gallbladder attack and therefore most likely to benefit from surgery with elective cholecystectomy.

The researchers later assessed the effectiveness of their predictive model in a recent study including 161,568 patients with an episode of symptomatic gallstones. Patients were aged 66 years and older and had an initial episode of symptomatic gallstones not requiring emergency hospitalization. The 2-year risk for gallstone-related emergent hospitalization was assessed using the predictive model.

“Our study specifically evaluated older patients. In this population, all are covered by Medicare, so insurance is not an issue,” Riall said. “However, the decision to perform elective gallbladder removal cholecystectomy is difficult because older patients often have co-existing chronic medical problems such as heart disease, high-blood pressure and diabetes, which increase their risk for complications from surgery. This has to be balanced by the fact that if complications do occur in these patients, the rate for complications and risk for dying from their gallbladder disease increase significantly.”

Model results

According to study results, patients at highest risk for an acute gallbladder episode are least likely to undergo cholecystectomy.

Within the 2.5 months after the initial symptomatic episode, 22.3% of patients at low-risk, 20.9% of patients at moderate-risk and 23.2% of patients at high-risk underwent elective cholecystectomy. Among those with no comorbidities, rates for elective cholecystectomy decreased from 34.2% in the group at low-risk to 26.7% in the group at high-risk. Only 9.5% of patients who did not undergo surgery were seen by a surgeon within the 2.5 months after their first acute gallbladder episode.

According to Riall, removal of the gallbladder seemed independent of risk.

“Ideally, operations or other treatments should be guided by patient risk — performing gallbladder removal in those at highest risk would prevent episodes of serious complications and improve outcomes,” she said. “Our data suggest that physicians are bad at predicting the overall risk; hopefully, physicians will be able to use our nomogram and risk prediction model to assess an individual patient’s risk for developing serious gallstone-related complications as well as assess their surgical risk. This information, if communicated well to patients, can help guide informed decision making and choose the right treatment for the right patients — in other words, maximize cholecystectomy rates in the patients at highest risk for developing complications as long as they can tolerate the operation.” – by Jennifer Southall

For more information:

Taylor S. Riall, MD, can be reached at The University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555. Email: tsriall@utmb.edu.

Disclosure: Riall reports no relevant financial disclosures.