BB&T Contributing Editor

WASHINGTON — The American Society for Metabolic and Bariatric Surgery (ASMBS; Gainesville, Florida) met here in mid-June with its new banner that added "metabolic" to its previous name, remarking on the newest understanding of the complexity of obesity.

No longer is it believed that a mechanical reduction of the size of the stomach, or bypassing part of the intestine, is the long-term cure for obesity.

This group of surgeons is dedicated to the treatment of metabolic disease and obesity, leading the path to better understanding of the root causes and then hopefully cures behind this worldwide epidemic that is caused by a plethora of various factors that are still baffling.

Previous thinking was that morbid obesity led to diabetes and could be cured by mechanically altering the alimentary tract, but current thinking proposes that it is a complex neuro-hormonal feedback to and from the brain and gut that allows for obesity and diabetes to occur, initiated by poor eating and exercise habits.

Long-term studies following patients who had bariatric surgery 10 to 15 years earlier have shown that weight re-gain is a common occurrence, suggesting more than just a re-routing of the intestines can cure it.

According to ASBMS, about 64 million adults in the US are considered obese, which is associated with many other diseases and conditions including Type 2 diabetes, heart disease, sleep apnea, hypertension and cancer. While 15 million people in the U.S. have morbid obesity and are clinically eligible for surgery, only about 1% or 205,000 in 2007 are being treated through bariatric surgery.

In an industry-sponsored workshop, "Economics and its Influence on the Evolution of Bariatric and Metabolic Surgery," Eric Finkelstein, PhD, director of public health economics at RTI International (Research Triangle Park, North Carolina) and author of the book The Fattening of America, offered his opinion on how America and soon the world — became obese.

"Economics drove us to obesity and economics may be our way out," he said. "It is no longer a problem of poverty. There are economic causes of obesity, such as the fact that we have made it easier and cheaper to consume bad food and more difficult and expensive to consume good food. Sodas and snacks have gone down in price and are quick and easy to eat (thanks, in part, to the microwave), while vegetables and fish have gone up in price and require some time to prepare."

He added, "It is harder to get accidental exercise, it costs more to get intentional exercise, and our leisure-time activities, which are passive, crowd out exercise. Obesity is a side affect of our own success," Finkelstein said.

Besides the economic drivers mentioned above, the consequences of obesity have been diminished due to pharmaceuticals such as statins and blood pressure meds that counteract the medical conditions caused by obesity. In addition, the costs of the cures (i.e., surgery, etc.) are borne by the entire population — both thin and not — through government or insurers, resulting in thin people contributing to the cure of the obese.

All of these reasons contribute to the finding that more rational people, and not just the uneducated, are becoming obese. "A successful obesity prevention program should make it cheaper and easier to be thin," Finkelstein said. "Currently the economics are working against this."

According to Finkelstein, for a change to occur the economics have to be reversed such that the thin are rewarded and the obese suffer financial consequences.

An economic factor preventing many of the potential patients in this 19 million-person pool is the cost of bariatric surgery, specifically the gastric bypass and Lap-Band procedures that can range from $20,000 to $30,000 and are the two most common procedures performed in the U.S.

In a nationwide survey of 409 bariatric patients conducted by Harris Interactive (Rochester, New York), affordability was cited as the No. 2 reason patients did not have the surgery, second only to not knowing enough about it (see Table 8).

One way to capture more patients into having the life-saving surgery is to make it more affordable as well as conquer their fears of surgery, which has several companies developing new products and procedures to meet these requirements.

Other than avoiding major surgery as it exists today by using a less-invasive, less-costly, yet possibly less-effective method for weight loss, another way to skirt the economics of reimbursement for bariatric surgery is to position the procedure as a cure for diabetes as opposed to weight loss.

Recent studies have shown a reversal of diabetes among bariatric surgery patients even before any weight has been lost.

Several reports delivered here showed a resolution of diabetes after patients received a gastric bypass, sleeve gastrectomy or other novel weight loss procedure. Although the mechanism of action is still unclear, the fact that many bariatric procedures reverse diabetes almost instantly is not only newsworthy, but may also be lucrative. When it comes to paying for a surgical procedure, bariatric surgery is held to a different standard than other procedures. Insurance companies would prefer to pay for prevention of obesity rather than surgery. But if the surgery is medically necessary to treat a disease such as diabetes, then they may be more likely to pay.

Unlike bariatric surgeons, endocrinologists have aligned themselves tightly with insurance companies and along with the American Diabetes Association, are a formidable advisory to get things done and reimbursed. Because of this, diabetes resolution was featured as a prime endpoint — not just weight loss — in measuring outcomes of bariatric procedures. Reimbursement for diabetes control may be the key to expanding the bariatric surgery market.

This new line of thinking pervaded the meeting in regards to focusing on diabetes resolution, as opposed to percent excess weight loss (EWL), once considered the gold standard for measuring bariatric surgery outcome. Now diabetes resolution — often measured in days — has stolen the limelight and for several reasons, some of which are economic as opposed to medically driven.

Type 2 diabetes affects 20 million Americans, or 7% of the population, and has much co-morbidity associated with it. Type 2 was once thought to be a disease of obesity and caused by excess weight, so the resulting reversal of diabetes, along with weight loss, that was found after bariatric surgery was not surprising.

A landmark study in rats that showed an immediate reversal of diabetes without accompanying weight loss when a plastic sleeve was placed in the duodenum forced thought leaders to re-think the mechanism of diabetes and the role gut hormones and peptides may be playing in root cause of the disease.

This study caught industry by surprise and several companies benefitted, while others may have to re-group based on this finding because they were not looking for diabetes resolution, but rather, weight loss.

One young company, GI Dynamics (Lexington, Massachusetts), has everything to gain from the movement to diabetes resolution. It has developed an endoscopically placed Teflon liner placed just beyond the pyloris.

This device, called the EndoBarrier, creates a mechanical bypass of the duodenum and proximal jejunum. It allows food to pass through the device, and allows bile and pancreatic enzymes to travel outside the liner, allowing bile and gut hormones to travel around the liner without touching the food until later in the gut, thus mimicking a gastric bypass.

The initial findings from an interim analysis were presented at the American Diabetes Association (Alexandria, Virginia) annual scientific session in San Francisco earlier in the month, where they were able to demonstrate resolution of diabetes in advance of weight loss one week after placement of the device. GI Dynamics has implanted 109 devices and has demonstrated 19% excess weight loss (EWL) at three months and 29% at six months.

These results of EWL alone are outstanding, and add to it the immediate reversal of diabetes, along with it being a simple outpatient procedure performed through the mouth without incisions, and the mix sounds like a winner.

Another novel company exhibiting here was EnteroMedics (St. Paul, Minnesota), which has developed the VBLOC vagal blocking system and a neuromodulation system that is comprised of a pacemaker-type and leads that are implanted laparoscopically around the vagal nerve.

The company's intermittent vagal blocking system involves a less-invasive option to gastric bypass and lap banding and provides a means of tricking the alimentary tract into feeling full after a small meal. Should the patient's digestive system outsmart the sensory impulses delivered by VBLOC, the therapy can be non-invasively adjusted to a new waveform to which the digestive tract may respond more optimally.

In a presentation by J. Toouli, MD, PhD, professor of surgery at Flinders University of South Australia (Adelaide), he compared the first-generation device with the company's second-generation system and was able to show a continued favorable safety profile with improved efficacy as measured by EWL.

EnteroMedics has begun a pivotal trial at 13 U.S. and two Australian sites, enrolling 300 patients in a double-blinded, 2-to-1, placebo-controlled, randomized trial that is anticipated to be unblinded in 3Q09.

Because the vagal nerves affect the release of gut hormones, some anticipate that the therapy may also help to reverse diabetes prior to significant weight loss something the company did not plan to evaluate specifically in its pilot trial and something worth investigating in today's market.

Revisional bariatric surgery has created its own new market. With about 20 million Americans who would qualify for bariatric surgery and only 200,000 of them actually having the surgery, one would think that the remaining market is so large that growing this market would be unnecessary.

But markets — like the gut — have a mind of their own, and just as we found the diabetes reversal a new market frontier, now revisional surgeries are creating a new market, albeit much smaller.

Weight re-gain is a sad but significant problem among weight loss surgery patients. Many require additional surgery following their original surgery, either because of side effects or weight regain. This market opportunity has allowed some companies a way to enter the market earlier than they would have if addressing the primary bariatric market.

One such company is USGI Medical (San Clemente, California), which has developed a platform for a variety of incisionless surgeries, including NOTES procedures, and whose device functions extremely well for restorative obesity surgery endolumenally, nicknamed ROSE procedures.

Chris Thompson, MD, director of bariatric endoscopy at Brigham and Women's Hospital (Boston), said in a postgraduate course on Therapeutic Endoscopy and Emerging Endoscopic Technologies, "There is significant industry activity in endoscopic treatments for obesity."

He presented results of 20 patients on whom he had used the USGI EndoSurgical Operating System (EOS) for ROSE procedures and demonstrated clinical evidence showing that it enabled surgeons and physicians to use an incisionless technique to reduce the size of the gastric pouch and stoma in patients who have regained weight after initial success with gastric bypass.

In poster presentation, "Endolumenal tissue plication with tissue-anchors as a treatment for dilated gastrojejunostomy and gastric pouch after gastric bypass: early clinical experience," Daniel Herron, MD, and colleagues used the EOS to create tissue folds around the stoma and in the stomach pouch of eight patients and found no major complications occurred and the only minor complications were sore throats.

"The patients in the study all had lost significant weight after gastric bypass, but slowly began to regain weight over time," said Herron, chief of bariatric surgery at Mount Sinai Hospital (New York). "Due to the scarring from the original procedure, open revision options have generally been excessively risky to perform for all patients with a large pouch or stoma."

He added, "By enabling us to perform this new incisionless revision procedure, these patients are back on the path to weight loss with barely any side effects."

Another not-so-new but revived surgery is that of sleeve gastrectomy, which has grown in popularity tremendously because it is easy to do, can now be performed endolumenally, and patients can later add another procedure if necessary.

Sleeve gastrectomy is the suturing of the stomach such that only a sleeve is left that allows for a limited amount of food passage and was once part of a procedure that also included a bypass component to it.

Super-obese patients often are unable to undergo surgery because they require dangerously high amounts of sedative due to their large size, have interrupted breathing patterns, and often chronic obstructive pulmonary disease (COPD).

These factors put them at risk for surgery, so it has been felt that if they could lose some of their excess weight prior to surgery, they could become a candidate for surgery with less associated risk. By performing the simpler sleeve part of the surgery first called "staging" their surgery they may lose enough weight to go back for the rest of their surgery.

Performing just the sleeve procedure caused enough weight loss that some of them never returned for the rest of the surgery, and also resulted in a new wave of "sleeve-only" procedures to be performed.

Simpler, easy to perform surgically, and now without incisions, the fad has caught on, with good weight loss results awaiting long-term studies to verify its durability.

Companies that may benefit from this new concept are those that have endoscopic staplers, among them Ethicon Endo-Surgery (Cincinnati), Covidien (Mansfield, Massachusetts) and Power Medical Innovations.

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