Belly Flops: Bariatric Surgery Complications

While bariatric surgery has been shown to improve a number of metabolic conditions, some patients experience negative outcomes. Educating both the clinician and the patient is vital, as is lifelong follow-up.

Nearly 35% of adults — about 78 million people — in the U.S. are obese. Of that number, approximately 11 million have a body mass index of 40 or higher, which makes them a candidate for weight loss surgery.

However, only a very small percentage of the extremely obese turn to bariatric surgery as treatment. For those who do have the surgery, it has shown to improve or resolve many obesity- related conditions including type 2 diabetes, high blood pressure, obstructive sleep apnea, and heart disease.

For some patients, the outcomes are not as successful. Post-surgical complications can arise creating several acute health emergencies. The most common are diarrhea and dumping syndrome, hypoglycemia, bone loss, and vitamin deficiencies.

“With bariatric surgery, the main challenge to being able to make these safe and effective procedures, is, number one, proper patient selection.” — Jeffrey Mechanick, MD, clinical professor, Medicine, Endocrinology, Diabetes and Bone Disease, Mount Sinai Hospital, New York

The Endocrine Society’s recently published Endocrine and Metabolic Medical Emergencies devotes a chapter to the topic and reports that these emergencies can occur after each of the three types of bariatric procedures: Roux-en-Y gastric bypass, laparoscopic adjustable gastric banding, and laparoscopic sleeve banding.

The chapter’s authors call for awareness of these complications by both the treating clinicians and the patients who are considering surgery. “With bariatric surgery, the main challenge to being able to make these safe and effective procedures, is, number one, proper patient selection,” says coauthor Jeffrey Mechanick, MD, clinical professor Medicine, Endocrinology, Diabetes and Bone Disease at New York’s Mount Sinai Hospital.

“You can easily see that there may be patients who are not followed by physicians and who wake up one day and see themselves as being very obese and then see a magazine advertisement for some doctor who does a lot of bariatric surgery and they think it’s a quick fix,” Mechanick adds. “So they call the doctor, travel to another state, and they have the procedure. It may be just one doctor in one clinic, they may or may not be accredited, and then [patients] go back home where nobody really has the expertise to follow them.”

Mechanick says these are the patients and the scenario that’s at highest risk for post-operative complications.

John Morton, MD, president of the American Society for Metabolic & Bariatric Surgery (ASMBS), differs and says that while the scenario of patients flying to out-of-town clinics occasionally occurred in the past because the surgeries weren’t often covered by insurance, things are different now.

“Bariatric surgery is pretty routinely covered by insurers, and as a result the insurers actually insist that patients come to accredited centers,” Morton says. “It’s a requirement.”

Morton, who has performed more than 2,000 bariatric procedures, says the overall message of ASMBS is that bariatric surgery is both safe and effective.

“The national 30-day mortality rates at this point are 0.1%, which makes it as safe as removal of the gallbladder or hip or knee replacement,” he explains.

“That being said, there are potential opportunities for complications after surgery. I think the one thing that we all agree upon is that these patients are unique patients and deserve specialized care, and that specialized care is delivered in an accredited center.”

Emergencies, Post-Op

Diarrhea and Dumping. About 10% –15% of patients experience fecal incontinence following bariatric surgery, according to the book chapter. The diarrhea and dumping syndrome is often accompanied by symptoms of abdominal pain and cramping, nausea, flushing, and light-headedness.

Hypoglycemia. Postprandial hypoglycemia may also develop but without any related abdominal pain or nausea. These rare hypoglycemia events can be severe, reports the chapter, with patients having blood glucose levels of 15–40 mg/dL.

“What we find is that sometimes patients aren’t hungry, which is an effect of the surgery where the hunger hormones, ghrelin, is actually decreased substantially after surgery,” Morton explains. “As a result, patients don’t feel hungry and sometimes skip meals. It’s important to know that if they skip meals that can lead to hypoglycemia.”

Bone fractures. Bariatric surgery increases the risk of a fracture by twofold, according to a 2014 study in Osteoporosis International. The study evaluated 258 patients — 90% of whom had a first gastric bypass at the Mayo Clinic. The average time to first fracture was around two to three years, says the study’s co-author Kurt Kennel, MD, of the Division of Endocrinology, Metabolism and Nutrition at the Mayo Clinic.

“We were more concerned that because fractures occur quite a few years after the surgery, providers would not recognize the potential connection,” he says. “Still, a fracture at any point in time could be disruptive.”

Kennel believes providers should consider the potential for bariatric surgery to have an adverse effect on bone when the patient already has established osteoporosis or, perhaps, in menopausal women with multiple risk factors for osteoporosis. “In such patients, providers want to make sure that patient is already receiving evidence-based osteoporosis screening and management prior to bariatric surgery,” he says.

Vitamin deThciencies. Nearly a quarter of patients who had restrictive procedures will develop a vitamin defi- ciency, says Kimberly Gudzune, MD, assistant professor at Johns Hopkins University School of Medicine. Gudzune authored a 2013 study in Obesity Surgery that found although vitamin deficiencies are common after bariatric surgery, they vary by the type of surgery performed.

“Patients who undergo gastric bypass or a malabsorptive surgery like a duodenal switch are more likely to have vitamin deficiencies than patients who have a restrictive procedure such as adjustable gastric banding,” she says.

Gudzune says that once a vitamin deficiency is identified, dietary change alone is not usually sufficient to correct the deficiency.

“Most patients need to be on vitamin supplements for the rest of their lives, so we need to make sure that patients continue to receive adequate nutrition and supplementation in order to avoid complications of severe vitamin deficiencies,” she explains.

The Need for Lifelong Care

Mechanick’s chapter ends with, “the risk of these conditions remains high, necessitating lifelong follow-up.” He doesn’t specify, however, who should provide the lifelong care or how frequent it should occur.

“We clearly avoid any kind of turf or political issues by stipulating who is providing that lifelong follow-up, but you can easily see that if it’s somebody who is complicated and has a lot of nutritional problems, then a physician with expertise in nutrition,” Mechanick explains. “If it’s somebody with hormonal or endocrine problems, an endocrinologist. And in all those cases, it can still even be a knowledgeable internist or general practitioner.”

Morton says the ASMBS is a big believer in followup. “Our policy has always been that patients should be followed-up in that bariatric surgery center,” he explains. “The usual routine is most surgeons will see their patients at two weeks, three months, six months, and one year and then, every year annually.”

“Most surgeons like to see patients annually because there may be surgery-specific questions that come up, but all of us try to work very closely with their referring doctors in making sure they get good coordinated care,” Morton says.

“There are potential opportunities for complications after surgery. I think the one thing that we all agree upon is that these patients are unique patients and deserve specialized care, and that specialized care is delivered in an accredited center.” — John Morton, MD, president, American Society for Metabolic & Bariatric Surgery

Coordinating Efforts

There’s a growing effort to make obesity treatment such as bariatric surgery more available to this country’s extremely obese. Last year, the ASMBS sponsored the Obesity Summit where about 26 different medical societies came together to discuss how best to educate patients, provide care, and coordinate that care.

“There’s still a lot of reluctance around referring physicians to even discuss bariatric surgery because they don’t feel equipped about how to talk to patients about obesity treatment options,” Morton says. “So, I think that’s still a big thing that they have to overcome, but working together we can do it.”

This year’s Obesity Summit will be held September 18–19 in Chicago.

— Fauntleroy is a freelance writer based in Carmel, Ind., and a regular contributor to Endocrine News. She wrote about diabetes and dietary supplements in the April issue.