FDA Panel Recommends Approval of New Obesity Device

June 17th, 2014 No comments »

StreetInsider.com is reporting that the Food and Drug Administration Advisory Panel today recommended approval of a new medical device from EnteroMedics, the Maestro Rechargeable System. The voting was somewhat mixed regarding the effectiveness of the device.

The Maestro Rechargeable System uses an electrical system called V-Bloc. V-Bloc delivers the electrical signal to the trunks of the vagus nerve, which sends hunger signals to the brain. The company states that the device decreases hunger pangs, digestive enzyme secretion and calorie absorption and increases the feeling of fullness. It would be offered to candidates for bariatric surgery who do not want the full surgical intervention.

The company’s press release notes, “In the most recent clinical trial, the ReCharge Study, VBLOC Therapy treated patients demonstrated a clinically meaningful and statistically significant excess weight loss (EWL) at 12 months of 24.4%, sustained out to 18 months. The majority (52.5%) lost 20% or more of their excess weight and nearly one-third of VBLOC Therapy treated patients lost 30% or more. The 24.4% average EWL far exceeds the 10% to 15% thresholds at which patients experience substantial positive health effects. Statistically significant improvements were observed in the VBLOC Therapy treatment group in total cholesterol, LDL, triglycerides, systolic and diastolic blood pressure, heart rate and waist circumference.”

The approval by the panel is likely to encourage a number of other developers of advanced technological strategies to treat obesity. More.

Keeping Up with Bariatric Surgery

May 12th, 2014 No comments »

Bariatric surgery continues to provide impressive outcomes. But how surgery achieves these outcomes is still unclear. What is known is providing new avenues for research.

Outcomes

A recent review of 14 studies involving 29,000 bariatric surgery patients and 166,200 nonsurgical controls of bias a more than 50% reduction in mortality amongst patients who had bariatric surgery. Bariatric surgery was associated with a significantly reduced risk of composite cardiovascular adverse events and was also associated with significant reduction in specific endpoints of myocardial infarction and stroke. And a study by Philip Schauer and colleagues published in the New England Journal of Medicine found, after 3 years of follow-up, that patients who received bariatric surgery and intensive medical therapy had better glycemic control than patients who received only intensive medical therapy. All patients had uncontrolled type 2 diabetes. 38% of surgical plus medical patients achieved the primary end point of HbA1c levels of 6% or less compared to 5% in the medical-only group. Weight loss differences were stark. The group receiving gastric bypass surgery had a 24.5% reduction in baseline weight and the group receiving sleeve-gastrectomy has a 21% reduction. Those in the medical-only group had a weight loss of 4.2%. The surgery plus medical group had greater reductions in medications and improved quality of life scores than the medical only group.

Earlier studies by Walter Poires at East Carolina University showed that, 16 years after Roux-en-Y gastric bypass (RYGB), patients mean weight loss was 55% of excess body weight, about 106 pounds. Mortality rates 9 years after surgery were 1% a year compared to 4.5% per year in the control group. Obesity-related comorbidities, including type 2 diabetes, hypertension, sleep apnea, non-alcoholic  steatohepatitis, stress incontinence and asthma, were resolved.

Mechanisms

How bariatric surgery resolves type 2 diabetes in over 80% of patients still remains to be determined. Theories abound. It has been observed that bariatric surgery blunts adaptive thermogenesis which takes place with other weight loss interventions, resulting in greater, more durable weight loss. Changes in gut hormones may also play a key role. A recent paper found that changes in bile acids in the blood. In a mouse study, the FXR gene influenced the outcomes in sleeve gasterctomy while mice without the gene had no effects. Researchers believe that it is bile acids in the blood, not the reduction in size of the stomach that produce the weight loss effects.

RYBG appears to work by reducing food intake and increasing resting energy expenditure. Taste, smell and appetite change after RYGB. A recently published survey of 103 RYGB patients reported high rates of changes in appetite, taste and smell up to 3 years after surgery. 73% of patients developed aversions to specific foods with meat, sweets, dairy and junk/fried foods leading the aversion list.

Changes in absorption of foods in the duodenum have triggered research and the development of a novel medical device, the EndoBarrier, being developed by GI Dynamics Inc. and presently in use in Europe, South America, Australia and Israel. Researchers are also looking at drugs which may mimic the effects of surgery, including a ‘cocktail’ of GLP-1, neuropeptide PYY, and oxyntomodulin, perhaps in combination with leptin to avoid the adaptive thermogenesis effect.

What has become evident is that earlier thinking on bariatric surgery, that operations are either restrictive or create malabsorption of nutrients, is inadequate to explain the power of the outcomes. Therefore, scientific focus has shifted to understanding the physiological changes brought about by bariatric surgery. This, in turn, is fueling the drive to find ways to achieve the effects of bariatric surgery without the surgery. As surgery is limited by costs, skills of surgeons, availability of facilities, etc., a non-surgical approach using the new understanding of the mechanisms has the potential to create new therapies.

Podcasts

There are two excellent podcasts on the mechanisms of bariatric surgery from the University of Alabama, Birmingham, NORC. See Lee Kaplan, Ph.D. M.D. and Randy Seeley, Ph.D.

 

Bariatric Surgery Safety and Effectiveness Supported

December 20th, 2013 No comments »


A meta-analysis of bariatric surgery has been published in JAMA Surgery. The analysis covers 164 studies covering 161,756 patients with a mean age of 44.5 and BMI of 45.6. The researchers found the within 30 day mortality rate was 0.08% and beyond 30 days 0.31%. BMI loss at 5 years was 12-17. Complication rate was 17%. The re-operation rate was 7%. Adjustable gastric banding had lower mortality and complication rates but the reoperation rates with higher and weight loss less substantial compared to gastric bypass. The authors conclude that the mortality rate was lower than reported in previous meta-analyses.

 

NIH Director Address Gastric Bypass Surgery and Diabetes

July 30th, 2013 No comments »

Francis Collins, director of the National Institutes of Health, has a new blog out on how gastric bypass surgery affects the development of type 2 diabetes.

Predictors of Weight Loss Success after Surgery Identified

July 8th, 2013 No comments »

Researchers at the Geisinger Obesity Research Institute have explored the reasons for the wide variation in weight loss outcomes following gastric bypass surgery. So they prospectively recruited 2,365 patients who underwent the surgery and stratified weight loss into three phases: early (0-6 months), nadir, and long term (over 36 months). They found that the pre-operative values associated with poorer weight at loss at the nadir and long term included higher baseline BMI, higher pre-operative weight loss, iron deficiency, use of any diabetes medication, non-use of bupropion, no history of smoking, being over 50 years old and the presence of fibrosis on the liver. See Still CS, Wood GC, Chu X, et al, Clinical Factors associated with weight loss outcomes after Roux-en-Y gastric bypass surgery. Obesity 2013, June 26 (epub ahead of print)

 

CMS Reviews Centers of Excellence for Bariatric Surgery

July 8th, 2013 No comments »

The Centers for Medicare and Medicaid Services have announced they are considering doing away with the requirement that, for Medicare coverage, bariatric surgery must be performed in Centers of Excellence. No other substantive changes to Medicare coverage are being made. Comments are being received until July 26, 2013. Click here for the CMS Proposed Decision.

 

Bariatric Surgery for low BMI Evaluated

June 12th, 2013 No comments »

The Agency for Healthcare Research and Quality has issued a Comparative Effectiveness Review on “Bariatric Surgery and Nonsurgical Therapy in Adults with Metabolic Conditions and a Body Mass Index of 30.0 to 34.9 kg/m2

Bariatric surgery is standard medical practice for patients with a BMI of 40 kg/m2 or for patients with a BMI between 35 and 40 kg/m2 who have significant comorbid conditions, such as type 2 diabetes. In recent years, there has been considerable discussion around providing bariatric surgery for patients with a BMI between 30 and 35 kg/m2 for type 2 diabetes and other metabolic conditions.

The reviewers for AHRQ concluded, “According to blood glucose outcomes, there is moderate strength evidence of efficacy for RYGB (Roux-en-Y Gastric Bypass), LAGB (Laparoscopic adjustable Gastric Banding), and SG (Sleeve Gastrectomy) as treatment for diabetes and IGT (impaired glucose tolerance) in patients with a BMI between 30 kg/m2 and 35 kg/m2 in the short term (up to 2 years). The strength of evidence for BPD (biliopancreatic diversion with duodenal switch) is rated low because there are fewer studies, and these have smaller sample size. Evidence on comparative effectiveness of surgical procedures is insufficient. Short-term adverse events are relatively minor; strength of evidence is low due to small sample size with low power to detect rare events. Strength of evidence is insufficient regarding adverse events in the long-term (2 years or more postsurgery). Longitudinal studies of bariatric surgery patients are needed to assess overall safety and comparative effectiveness regarding diabetes-related morbidity such as kidney failure and blindness.”

 

Christie’s Surgery Covered by Insurance

May 7th, 2013 No comments »


Governor Christie’s surgery was covered by state insurance, kind of. Here is what he said at a press conference this afternoon:

Question: [inaudible]

Governor Christie: My insurance. Yeah. The insurance that I pay for, yeah.

Question: [inaudible follow-up]

Governor Christie: No, I’m not going to price it out for you. No. No. No. Anymore than you have any right to know what Sheila pays for when she goes to the doctor, what Armando pays for when he goes to the doctor or anybody else. No, you don’t have a right to know that, that’s my personal business. That’s called HIPAA. That’s a federal statute. Familiarize yourself with it.

Question: [inaudible follow-up]

Governor Christie: Yeah. It is a procedure that is covered when you go through the steps that you need to go through by the State Health Insurance Plan that myself and my family are covered by. Yes.