Contributed by Daniel B. Leslie, M.D., Director of Bariatric Surgery, University of Minnesota Health
Innumerable studies have shown that successful weight loss is associated with better control of diabetes and other diseases associated with obesity. The National Institutes of Health recommends that patients with obesity target a weight loss of 10%. According to recent studies, a 10% weight loss may be achieved by as many as 36% of patients after one year of intensive lifestyle intervention.1 With surgical interventions, up to 99% of patients achieved a 10% weight loss after two years and 96% did after six years.2 Mortality rates for weightloss surgery are currently 0.2% or lower, although many primary care providers are reluctant to refer patients for weight-loss surgery due to fear of complications.
Because our M Health physicians have a long history of researching and providing bariatric surgery, we recognize the health benefits and some of the more serious long-term side effects of weight-loss operations involving the small intestine. Our program has treated more than 2,000 patients with weight-loss operations over the past eight years. Success in weight-loss surgery outcomes for our patients is dependent on several factors:
Patients are potential candidates to undergo weight-loss surgery if they have a body mass index (BMI) of 40 kg/m2 or greater or a BMI between 35 and 39.9 kg/m2 and one or more serious comorbid conditions, such as diabetes, obstructive sleep apnea, or hypertension.
Four operations to treat these levels of obesity are recognized: vertical sleeve gastrectomy, Roux-en-Y gastric bypass, adjustable gastric banding, and biliopancreatic diversion with duodenal switch. All are performed laparoscopically at University of Minnesota Health facilities; however, we have identified that some are becoming more prevalent.
From an analysis of a large collection of national data, our bariatric-team researchers have documented a drop in Roux-en-Y gastric bypass surgeries, from 52% of all bariatric procedures in 2008 to 32% in 2014, as well as a decrease in adjustable gastric banding procedures, from 42% of procedures in 2008 to only 4% in 2014. Vertical sleeve gastrectomy procedures, however, rose from 3% of procedures in 2009 to 52% in 2014.3 It is fully expected that this trend will continue.
These patterns in procedure selection are also reflected in the University of Minnesota bariatric surgery program. In 2015, the Roux-en-Y gastric bypass accounted for only 2.9% of procedures, while our patients chose vertical sleeve gastrectomy 95% of the time.
A better understanding of the shortand long-term risks involved may have led to this large shift in procedure choice over the past eight years. FDA studies documenting weight-loss outcomes after implantation of gastric bands (LapBand and RealizeBand) showed that patients lost on average about 40 pounds after surgery. Patient frustration with the gap between expected and achieved weight loss led, in many cases, to procedures where the implanted bands were over-tightened. This approach resulted in side effects or complications and, often, subsequent band removals. Some complications required emergency room visits, hospitalizations, or surgery to resolve. As a result, the demand for adjustable gastric band procedures dropped as patients came to understand that most bariatric surgeons were taking out more bands than they were placing.
The vertical sleeve gastrectomy became a stand-alone bariatric procedure in 2010. The procedure involves removal of a large volume of the stomach without altering the small intestinal anatomy. A narrow tube is made from the remaining stomach, which assists patients in food volume and hunger control. Because there is no intestinal rearrangement, patients do not suffer the effects of micronutrient malabsorption, which is commonly diagnosed after the Roux-en-Y gastric bypass operation. With vertical sleeve gastrectomy, food follows a normal pathway through the stomach, and protein deficiency does not develop as a result of malabsorption. Peptic ulcer disease is not frequently seen, though if present, all portions of the stomach and duodenal anatomy can be visualized after surgery. The main risks associated with vertical sleeve gastrectomy include staple line leak (2%), stricture (1%), and bleed (1%). These events occur almost exclusively in the perioperative timeframe. Heartburn and reflux may occur as well, nessitating long-term acid reduction. The long-term outcomes after sleeve gastrectomy are not established. At three years, weight loss after sleeve gastrectomy is over 20%.4
In the University of Minnesota Health bariatric surgery program, overall health considerations are the number one objective. At the start, an evaluation of the patient’s nourishing food choices and eating behaviors, mental health and psychosocial support, physical activity levels, damaging substance use and behaviors, and sleep patterns is conducted. Appropriate interventions are recommended as part of preoperative planning.
We make smoking cessation mandatory among our patients. We check patients’ progress through examining biochemical markers (typically gathered through urine cotinine testing). Patients with a history of tobacco addiction, moreover, are no longer offered procedures that might interfere with their long-term health. Tobacco use in association with the Roux-en-Y gastric bypass operation has a fairly high incidence of peptic ulcer disease and its manifestations, including upper gastrointestinal bleeding, stricture, or perforation.
Our weight-loss surgery program requires patients to pursue weight loss prior to surgery. Significant medical data suggest that even a little weight loss can improve health conditions such as diabetes, heart problems, and obstructive sleep apnea. Weight loss can reduce the risks associated with laparoscopic surgery, which puts some stress on the body, and allow for better outcomes. It can also provide the surgeon with a better view of the upper stomach so that the operation can be performed more efficiently. By working to reduce their weight, patients better understand that surgery is not a quick fix and that long-term outcomes are highly dependent on preoperative preparation. It also helps align their interests with those of their primary care provider and surgeon. In a study of a large group of patients undergoing Roux-en-Y gastric bypass between 2009 and 2012, our bariatric surgery outcomes team noted significant benefits in preoperative weight loss. Patients who lost 10 pounds or more (24 pounds average) before surgery had a total weight loss of 90 pounds two years after surgery. Those who lost fewer than 10 pounds (4 pounds average) had two years after surgery, a total weight loss of 55 pounds.
Long-Term Postsurgical Care and Weight Management
Postsurgical follow-up is more frequent during the first year after surgery and then routine laboratory testing and visits occur at annual intervals. Patients manage a healthy weight with the assistance of an interdisciplinary team of medical weight-management providers, registered dieticians, physical therapy experts, and psychologists.
FDA-approved medications to control appetite and cravings may be prescribed to assist with food intake behaviors, aid in treating weight regain, or provide a modicum of control once plateau weights are achieved. Patients are also assisted with understanding what their healthy weight targets may be and how they differ from unrealistic ‘ideal’ weight targets, which may not be achievable in a healthy way.
Our colleagues in interventional and luminal gastroenterology help manage side effects and complications. They assist with endoscopic ultrasound-guided and complex pancreatobiliary interventions, along with endoscopic treatments of gastro-esophageal dysfunction. Hematology and endocrinology evaluations help in managing iron and vitamin deficiency as well as side effects related to post-gastric bypass hypoglycemia.
Research on Weight-Loss Procedures
Since the 1960s, University of Minnesota faculty have made rich contributions to the field of metabolic research, achieving new discoveries and seeking to make weight-loss operations even more effective. In the past 10 years our research team has completed national studies on intragastric balloon implantation (RESHAPE DUO, FDA-approved, 2015), vagal blocking (Enteromedics Maestro Device, FDAapproved, 2015), and adjustable gastric band implantation (REALIZEBAND, FDA-approved, 2007), as well as studies on two endoscopic weight-loss procedures (TOGA and ESSENTIAL studies).
We are currently conducting an international randomized study evaluating methods of diabetes control after gastric bypass, comparing intensive medical treatment to medical management alone. This study has documented improved glycemia, systolic blood pressures, and cholesterol control after Roux-en-Y gastric bypass. The durability of this effect is being further evaluated.
A separate focus is the study of adipose tissue biology and the complex mechanisms associated with rapid weight loss after surgery. We are also seeking to better understand changes in the gut microbiome. Obesity is associated with a significant alteration in the gut microbiome, which changes dramatically after surgery. In controlled settings, patients have been providing stool samples so that these changes can be documented and better understood. Characterizing these changes will be critical towards understanding how we might better improve outcomes in the future.
For further information on our program, please visit our website.
Article appears in MetroDoctors. 2016;18(2):20-21. MetroDoctors is the journal of the Twin Cities Medical Society.