Bariatric surgery is the most effective method currently available to treat obesity. In the first few months after surgery, patients typically experience significant weight loss. However, rapid weight reduction can lead to the development of gallstones and biliary disease, described in up to 40% of post-bariatric patients, according to our research recently presented at the 2018 American College of Gastroenterology Annual Meeting.
In addition, obesity even without surgery is a risk factor for gallstone development. To avoid these complications, the gallbladder was removed during open bariatric procedures in the past. Laparoscopic bariatric surgeries are the procedure of choice today, with laparoscopic Roux-en-Y gastric bypass nearly tripling from 2003 to 2008. However, with the advent of laparoscopic surgery, concomitant cholecystectomy with bariatric surgery has become controversial. Some studies have suggested that in fact, cholecystectomy should be avoided during the index bariatric procedure as the need for subsequent cholecystectomy is low overall. This has led to a significantly decreased rate of concomitant cholecystectomy from 26.3 % in 2001 to 3.7 % in 2008.
We hypothesized that this change in practice may increase gallstone-related complications in post-bariatric patients. The aim of our study is to assess if admissions for biliary diseases such as acute pancreatitis, acute cholecystitis, acute cholangitis, and cholecystectomy have increased in this patient population. For our study, we analyzed the National Inpatient Sample (NIS), the largest publicly available inpatient database in the United States of nonfederal institutions, with approximately 1,000 hospitals participating and information on over 7 million inpatient admissions. We assessed admissions for biliary diseases in patients who have their bariatric surgery prior to 2006 or in 2006 and compared them to post-bariatric patients admitted in 2014 for biliary complications, with bariatric surgery in 2014 or prior to 2014. We also analyzed admissions for biliary diseases in 2006 and 2014 in patients without bariatric surgery.
We found that from 2006 to 2014, there has been an approximately 10-fold increase in hospital admissions for biliary diseases and cholecystectomies in patients with a history of bariatric surgery. There was no significant change in admissions in patients without bariatric surgery between 2006 and 2014 admitted for the same biliary diseases or surgery. The relative proportion of post-bariatric patients who were admitted for acute cholecystitis and acute cholangitis, for example, increased from 0.0086% in 2006 to 1.2% in 2014 and from 0.089% in 2006 to 0.9% in 2014, respectively. Notably, mortality was low and the length of stay was shorter for the post-bariatric patients who also were younger than the non-bariatric cohort.
Our team used a retrospective study design based on coding records, with possible errors due to incorrect coding, and increase over time in the total number of patients with prior bariatric surgery. Another possible explanation is the relative increase in sleeve gastrectomies compared to other bariatric procedures. Cholecystectomies are not usually done during sleeve procedures. A recent study showed increased 30-day readmissions for acute pancreatitis after a sleeve gastrectomy compared to gastric bypass. To more accurately assess this trend, prospective cohort studies of bariatric surgery patients are needed. Retrospective studies of individual centers comparing gallstone-related disease in bariatric patients who had or not had cholecystectomies could also be valuable.
Our study found a significant increase over the past decade in hospitalizations for acute cholecystitis, acute cholangitis, acute pancreatitis, and cholecystectomies in patients who have undergone bariatric surgery. Both physicians and patients should be aware of the increased risk of gallstone-related disease in post-bariatric patients. In the appropriate clinical scenario, physicians should have a low threshold to initiate appropriate treatment, especially if the patient has not undergone a cholecystectomy already. Also, physicians should remind their patients with recent bariatric surgery to take prophylactic medications to decrease the risk of gallstone formation. There is evidence that patients are not compliant with this approach, and patient education may be helpful in that aspect.
Finally, bariatric surgery is overall a safe and effective method to lose weight. Although we noted an increase in biliary disease, this should not discourage patients from undergoing bariatric surgery. These complications are seldom severe, and we have effective methods to treat them if they do develop. Laparoscopic surgery is safer for patients overall. Further research in medical or surgical interventions that could potentially decrease the risk of gallstone formation is needed.
Dr. Violeta B. Popov is an assistant professor at the NYU School of Medicine and the director of bariatric endoscopy at VA New York Harbor Healthcare System.
Andrew Thompson is a medical student.