When Your Patient Undergoes Bariatric Surgery

Matthew F. Watto, MD; Paul N. Williams, MD


July 06, 2021

This transcript has been edited for clarity.

Matthew F. Watto, MD: Welcome back to The Curbsiders. I'm Dr Matthew Watto here with my good friend, Dr Paul Williams. Tonight we're going to be talking about some of the expert tips we've learned about caring for the patient who has undergone or is going to undergo bariatric surgery. Paul, why don't you start us off with your favorite pearl from the great discussion we had with Dr Vivian Sanchez, who's up at Boston University, my alma mater, just in case you didn't know.

Paul N. Williams, MD: Dr Sanchez was amazing. We started by talking about the potential benefits of bariatric — or as she referred to it, metabolic — surgery, contrasted with medical weight loss plans. It just seems to work much better. Unfortunately, the long-term success of medical weight loss is not that great and metabolic surgery seems to have much better efficacy in the long term. There's a little bit of variation by procedure, but patients can expect to lose 60%-70% of excess weight. In addition to the weight loss, patients can expect improvements in quality of life. More recently, it's been found that patients who undergo metabolic surgery seem to have better mortality as well. I often thought of the metabolic improvements that occurred as a function of the weight loss that happens over time, but it actually happens pretty quickly.

Watto: But we don't understand why. Another thing that struck me was the use of the gastric sleeve procedure. I thought the gastric sleeve had fallen out of favor. But it turns out that gastric sleeve and the Roux-en-Y gastric bypass, which was the most common procedure back in the day, I thought the metabolic benefits were associated with only the Roux-en-Y. But actually something about stapling the stomach in the gastric sleeve produces the metabolic benefits as well.

You mentioned the excess weight loss of 60%-70%. Dr Sanchez said that if the patient has 100 pounds of excess weight, 60-70 pounds can be lost following surgery. With medical therapy, we high-five if we can get a 10% weight loss. It's very hard for patients to maintain that. She pointed out that the mortality risk is less than 1%. I imagine that if the metabolic conditions that they developed as a result of obesity continue, their mortality is going to be higher than that.

I have struggled with what to do for follow-up after the procedure. What tests should be ordered and who does it? Dr Sanchez said that 5 years after surgery, patients usually follow up with the surgeon, most likely as part of the quality measures the surgeons and bariatric surgery centers are held to.

The American Society for Metabolic & Bariatric Surgery, along with other organizations, put out great guidelines in 2019 that tell you step by step what you need to do, and what you need to check all along the way.

In the first year, labs are ordered about a month postoperatively and are repeated at 3, 6, and 12 months. Thereafter, depending on the results of those earlier rounds of testing, you can relax it a little bit. The guideline makes suggestions. After a Roux-en-Y or the biliopancreatic diversion, patients are prone to a lot of micronutrient deficiencies. Following the gastric sleeve, anemia is more common. Do you have a set panel of labs to order built into your electronic record?

Williams: Not yet, but knowing about the existence of the guidelines, I'm referring to them frequently. That's one thing I took away from this podcast — that there are some well-established criteria for the pre-op workup and post-op management of patients undergoing bariatric surgery. We don't have to guess at it anymore; the guidelines are really explicit. I have not gotten so sophisticated as to put together an order set, but at least now I know what to order.

Watto: For all patients, the panel includes a CBC, comprehensive metabolic panel, lipids, A1c, and thyroid. You can check vitamin B1 and vitamin B12 in the first year. And then depending on what surgery they had, you might also be checking vitamin D and parathyroid hormone and vitamins A, E, and K, and perhaps even zinc, copper, and selenium. By the time it's in my court, I'm selectively looking for a lot of these nutrient deficiencies, but I'm certainly checking for anemia pretty aggressively. Paul, what else are you looking out for?

Williams: In the immediate postoperative period, there are a couple of complications. The one that I was most unaware of is symptomatic cholelithiasis; particularly after gastric bypass surgery, they have a number of specific risks. They present with abdominal pain and need urgent evaluation because the complications include marginal ulceration and what's called a dilated remnant.

If the patient comes to you in the immediate postoperative period with abdominal pain, they should be evaluated by their surgeon pretty quickly. And then Dr Sanchez raised the point about one of the specific complications of gastric sleeve surgery, which is worsening gastroesophageal reflux, as well as an increased risk for Barrett's esophagus, even in the absence of reflux symptoms. So much so that her own personal practice is to send those patients for upper endoscopy after 3 years to evaluate for that, just to make sure that it hasn't developed over time, which I thought was pretty interesting.

Watto: I had no idea about that. It makes sense about the gastric sleeve. She said that if a patient had bad reflux that was difficult to control at baseline, she would even steer away from that surgery because it would be likely to get worse.

We also asked her specifically about alcohol. She basically said that the absorption of alcohol can be different in patients after their bypass surgery, and they are at more risk for some of the harmful effects than they might be otherwise. They might become intoxicated more easily. One of the experts was saying that there is increased risk for liver injury by drinking after bariatric surgery. So they try to discourage patients from drinking any alcohol at all. If the patient is going to a wedding and wants to have a glass of wine, they should test it out at home first, and be aware that a full glass of wine might be too much early on after surgery. How it might affect them is unpredictable. If your patient asks you about that, they have to be careful with alcohol, especially early on. Even in the long term, it's recommended that they don't drink, although I'm sure people do it.

Click to hear our full conversation: Bariatric Surgery for the Internist with Dr. Vivian Sanchez.

And you can also join our mailing list and get a PDF copy of our show notes every week.

Thank you for watching.

The Curbsiders are a national network of students, residents, and clinician educators from across the country, representing 15 different institutions. They "curbside" experts to deconstruct various topics in the world of medicine to provide listeners with clinical pearls, practice-changing knowledge, and bad puns. Learn more about their contributors and follow them on Twitter.

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