Medical Device Daily Contributing Writer
WASHINGTON — With diabetes resolution stepping into the medical limelight, this year's meeting of the newly renamed American Society for Metabolic and Bariatric Surgery (ASMBS; Gainesville, Florida), held here last week, saw several companies benefitting, while others may have to regroup based on the finding because they were looking instead for weight loss.
What is obvious is that the number of companies in the space is growing (see Table 1 on p. 7).
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 at ASMBS was EnteroMedics (St. Paul, Minnesota), which has developed the VBOLC 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.
During a postgraduate course on "Therapeutic Endoscopy and Emerging Endoscopic Technologies," Chris Thompson, MD, director of bariatric endoscopy at Brigham and Women's Hospital (Boston), said, "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 a 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) and Covidien (Mansfield, Massachusetts).
The simplification of bariatric procedures holds a great deal of promise for companies active in the space (see Table 2 for some of the key attributes that are driving the growing acceptance of such procedures).