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Diabetes boosts bariatric surgery complications

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Huge patient numbers confirm diabetes’ risk

Most bariatric surgeons believe that patients with diabetes who undergo this surgery will have more complications than will patients without diabetes, based on their anecdotal experience and findings from previous, smaller studies. But in Dr. Wheeler’s report, we see this demonstrated in an incredibly large number of patients. This is one of the first studies to use 3 years of data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program, which included more than half a million patients.

Dr. Corrigan McBride, professor of surgery and director of bariatric surgery, University of Nebraska Medical Center, Omaha

Dr. Corrigan McBride

The results show that we need to carefully think about our bariatric surgery protocols, and about patient selection. It also means we need to focus on modifiable risk factors such as perioperative glycemic control. Having major surgery, and recovering from it, is like a marathon, and so patients should not have surgery without first preparing months in advance: quitting smoking, becoming more physically active, and doing a better job controlling blood sugar. Some reports suggest bariatric surgery patients benefit from a couple of weeks on a “liver-shrinking” diet before surgery, using replacement meals or liquids to reduce glycogen stores and decrease insulin resistance.

A randomized study involving more than 18,000 cases showed that putting bariatric surgery patients on an “enhanced recovery program” before surgery and including measures that minimized insulin resistance and catabolism perioperatively led to a substantial reduction in extended length of stay (Surg Obes Relat Dis. 2019 Nov;15[11]:1977-89). In routine care, bariatric surgeons are now often routinely using “prehabilitation” to prepare patients for surgery.

Corrigan McBride, MD , is professor of surgery and director of bariatric surgery at the University of Nebraska Medical Center in Omaha. She had no disclosures. She made these comments in an interview.



U.S. patients with diabetes who underwent bariatric surgery during 2015-2017 had a 49% higher rate of deep surgical-site infections and a 31% higher rate of 30-day ICU admissions, compared with patients without diabetes, in an analysis of more than 550,000 patients who underwent this surgery.

Dr. Andrew A. Wheeler, chief of metabolic and bariatric surgery, University of Missouri, Columbia Mitchel L. Zoler/MDedge News

Dr. Andrew A. Wheeler

The analysis also showed that among patients with diabetes undergoing bariatric surgery, those with insulin-dependent diabetes had significantly higher rates of these and other complications, compared with patients with diabetes but no insulin dependence, Andrew A. Wheeler, MD, said at a meeting presented by The Obesity Society and the American Society for Metabolic and Bariatric Surgery.

The specific factors driving these observations remain unknown, but may relate at least in part to the efficacy of glycemic control in patients during the months and weeks before surgery, said Dr. Wheeler, chief of metabolic and bariatric surgery at the University of Missouri in Columbia.

“Perioperative blood glucose control reflected in hemoglobin A1c may help us understand if certain patients with diabetes are at increased risk of surgical complications,” Dr. Wheeler said during his talk. “We need to see whether preoperative hemoglobin A1c tracks with the rate of complications,” he added in an interview. “Some surgeons will defer surgery until the level goes down, but right now, everyone uses a different level.”

The study by Dr. Wheeler and associates used data collected from essentially all the bariatric surgeries done at the roughly 840 U.S. centers accredited to do the surgery during 2015-2017 – a total of 555,239 patients – in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program run by the American College of Surgeons and the American Society for Metabolic and Bariatric Surgery. The cohort included 413,239 patients without diabetes and 136,010 with diabetes, with the remainder having an unknown status. Nearly all patients underwent either sleeve gastrectomy or gastric bypass, with significantly more patients, 74%, having sleeve gastrectomy in the group without diabetes, and 62% of those with diabetes undergoing sleeve gastrectomy.

Patients with diabetes uniformly had significantly higher rates of complications as measured by several parameters, and among those with diabetes, the complication rates were highest in those with insulin dependence. The researchers ran a multivariate analysis that controlled for many demographic and clinical variables, and found that despite these corrections, patients with diabetes, and especially those with insulin dependence, had higher relative rates of many complications that were statistically significant. In addition to the increased rates of deep surgical-site infections and 30-day ICU admissions, patients with diabetes had a 54% relatively increased rate of wound disruption, and a 29% increased relative rate of superficial surgical-site infections, compared with those without diabetes. And among patients with diabetes, those with insulin dependence had a 40% increased rate of surgical-site infections, a 74% increase in progressive renal failure, and a 39% increased rate of hospital readmission relative to patients with diabetes that was not insulin dependent, Dr. Wheeler reported.

The absolute complication rates were, in general, low. For example, the total rate of superficial plus deep surgical-site infections was less than 1% both in patients with diabetes and those without, although the rate rose above 1% in patients with insulin-dependent diabetes. The most common complication reported by Dr. Wheeler was 30-day hospital readmission, which was 4.0% in patients without diabetes, 4.8% in those with diabetes, and 6.4% in patients with insulin-dependent diabetes. The data also showed that gastric bypass led to more complications than did sleeve gastrectomy, but complications with both types of surgeries increased in patients with diabetes, compared with those without diabetes.

Dr. Wheeler had no disclosures.

SOURCE: Wheeler AA et al. Obesity Week 2019, Abstract A133.

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