BBI Contributing Editor
WASHINGTON Top bariatric surgeons from around the country, along with key policy makers and major insurance carriers were invited to a National Institutes of Health (NIH; Bethesda, Maryland) consensus meeting held here in May, sponsored by the American Society of Bariatric Surgeons (ASBS; Gainesville, Florida). The objective of the meeting was to develop an evidence-based overview of the state of bariatric surgery and provide a reliable reference for patients, surgeons and third-party payers to address the nation's future for managing the national obesity epidemic.
Obesity is the most prevalent epidemic in the U.S. with 15 million people one out of every 20 having a body mass index (BMI) of more than 35 kg/m2. Obesity has medical, social, psychological and economic consequences. Obesity brings along with it co-morbidities such as diabetes, hypertension, bone and joint ailments, apnea, cardiovascular problems, etc. The morbidly obese are refractory to diet, drug therapy and other forms of medical treatment, but can achieve a substantial, sustained weight loss after bariatric surgery which results in loss of the associated co-morbidities as well. About 120,000 bariatric operations were performed last year, triple the number performed just two years ago, or a 500% increase in number of bariatric surgeries performed annually since 1992. Industry estimates are that there will be more than 200,000 bariatric surgeries performed in the U.S. by 2005. The number of practicing surgeons who are members of the ASBS has increased from 258 in 1998 to 1,070 in 2003. These numbers are skyrocketing, indicating the growing epidemic of obesity in our nation and the use of bariatric surgery as a solution.
Three main categories of bariatric procedures are currently being performed: restrictive, such as the Lap-Band; malabsorptive, such as the duodenal switch; and a combination of both such as the Roux-en-y gastric bypass (see Table 1). The later is the gold standard, as a substantial body of literature endorses its sustained weight loss and low rates of morbidity and mortality.
Philip Schauer, MD, of the University of Pittsburgh (Pittsburgh, Pennsylvania), presented data on the Roux-en-y gastric bypass, the most common bariatric procedure performed in the U.S., which results in both restriction of intake and malabsorption to produce weight loss. Schauer noted that the advantages of the procedure are excellent weight loss, good long-term results and well-tolerated solid food, while the downside includes potential nutritional deficiencies, some perioperative morbidities and a long recovery. Since surgeons have started performing the procedure laparoscopically, the later disadvantage has been reduced (see Table 2). According to the ASBS, in 2003, 56% of all bariatric surgeries were performed laparoscopically.
The second-most-common procedure in the U.S. is the laparoscopic adjustable gastric band, named the Lap-Band, by Inamed (Santa Barbara, California). Although it is second in popularity in the U.S., it is by far the leader worldwide, having been implanted in more than 100,000 patients. While it has experienced great success in Europe, Lap-Band's market entry into the U.S. has been a little less stellar. Jaime Ponce, MD, of Dalton Surgical Group (Dalton, Georgia), presented the history and current data regarding this product, a silastic band that is placed around the upper portion of the stomach and is adjustable through a subcutaneous port. It also is a reversible procedure, which contributes to its appeal as a low-risk option. Since it was designed to be placed laparoscopically on an outpatient basis, one of the initial barriers to success for the Lap-Band in the U.S. was that those surgeons with little laparoscopic experience had a longer learning curve than anticipated and experienced more complications.
The greatest success with Lap-Band weight loss occurs when patients have follow-up adjustments on an ongoing basis. Two different factors arose in the U.S. that were not an issue in Europe and contributed to the lack of follow-up for adjustments and consequent success. Typically, U.S. surgeons are not familiar with patient after-care because they are usually called to "fix" something and then refer the patient back to their primary care physician. With the required interval adjustments for Lap-Band patients, surgeons' practice patterns and office management had to adapt to this new thinking. In addition, U.S. patients are more likely to feel "cured" following surgery, and when their weight loss plateaus, they either blame their surgeon or themselves and are too embarrassed to return to the surgeon. Both the surgeons and patients need to be educated on the value of follow-up visits with the Lap-Band, Ponce said.
The least common bariatric procedures performed are the duodenal switch, or the biliopancreatic diversion, often categorized together since they are both malabsorptive procedures. These procedures result in the highest weight loss but also the highest morbidities. Patients are required to follow a strict nutritional supplement program following surgery or are subject to nutrient deficiency syndromes such as anemia, osteoporosis, alopecia, lethargy and protein deficiency syndromes. Unless the patient is highly motivated, organized and extremely compliant, there can be severe problems with nutrition, which could even lead to death. It was suggested that patients over the age of 60 should not be considered for such procedures. Interestingly, Nicola Scopinaro, MD, of University Ospedale San Martino (Genova, Italy), said he has had tremendous success with his Italian patients, showing a 70% excess weight loss at 25 years after surgery and not one patient ever having serum cholesterol levels over 200 mg. He attributed their success to his requirement of 100% compliance with a nutritional program for all his patients as well as the fact that in his culture the surgeon is god, and patients follow what they are told to do, unlike most Americans.
In all bariatric surgeries, the outcomes and morbidities are almost linearly proportionate to the patient's amount of excess weight the heavier the patient, the greater the risk of the surgery and the more morbidity associated with it. To provide for better patient care with a better prognosis, earlier intervention or a staged approach was proposed. The staged approach involves using the Lap-Band or other restrictive measures first to get the patient down to a lower-risk operable weight, followed by a Roux-en-y gastric bypass. Others suggested methods of earlier intervention whereby bariatric surgery would be prevented altogether. Since it is well documented that medical and behavioral treatments do not prevent obesity, more early interventional techniques are being explored.
Besides the Lap-Band as an early intervention, there are other similar band-type products that mimic the Lap-Band, including the Swedish Adjustable Gastric Band by Obtech Medical, acquired by Ethicon Endosurgery (Cincinnati, Ohio), that is in clinical trials in the U.S. Two other band companies the Helioplasty band from France and the Advanced Medical Interventions band from Germany are not entering into clinical trials here but have been used in Europe.
Transneuronix (Mt. Arlington, New Jersey) is developing a less-invasive, early intervention product an implantable electrostimulation device, much like a pacemaker. Leads are surgically placed on the stomach in a short outpatient surgery and then stimulated at various times, which causes a decrease in gastric emptying and the feeling of satiety. In treating over 500 patients worldwide since 1995, the device has been found to be safe, but only successful in about 20% of the obese population. Scott Shikora, MD, associate professor of surgery at Tufts University School of Medicine (Boston, Massachusetts), has developed an algorithm that can be used preoperatively as a predictor for which patients will be able to achieve optimal results described as an excess weight loss of 25% at 18 months. This device may in fact be used as an appropriate tool for those patients who re-gain weight post-surgery or for those who are trying to avoid bariatric surgery. There is no downside to trying this intervention first, as there is no permanent restriction, no malabsorption and the patient can always go on to bariatric surgery if necessary.
Other companies working on implantable electrostimulation devices include Impulse Dynamics (Tirat Carmel, Israel), Cyberonics (Houston, Texas), Medtronic (Minneapolis, Minnesota), Advanced Neuromodulation Systems (Plano, Texas) and Intrapace (Menlo Park, California), the latter of which use an endoscopic delivery. Although Transneuronix appears to be ahead of the pack in addressing this moderately obese population, the fact that so many others are interested is an endorsement for less invasive early intervention.
Other endoscopic approaches are being used by Silhouette (Mountain View, California) and Satiety (Palo Alto, California) where a flexible scope is inserted into the stomach and restricts the size of the stomach pouch from within. These procedures also offer less-invasive, early intervention in order to avoid the risks of bariatric surgery and are designed for interventional endoscopists. It probably will be two to three years before any of these early intervention products are on the market.
Satiety's other product is a gastric balloon that once inserted can be inflated or deflated from an external port. Inamed also is working on a gastric balloon to be used initially as a "staging" product that is, to get an extremely obese patient's weight down to a more acceptable weight for surgery in order to reduce surgical risk. These balloons are to be extracted after six months following the criteria set forth in 1977 after failures of early balloons that became brittle over time from exposure to the stomach's acidic contents, and then, while being passed through the digestive system, obstructed the bowel, sometimes resulting in patient death. The goal of all early interventions is to treat the patient before bariatric surgery with its associated risks is necessary.
Meanwhile, Sanofi-Synthelabo (Le Plessis Robinson, France) is in Phase III clinical trials on a new drug called Rimonbant that eliminates hunger. It has been developed under an entirely novel drug discovery pathway that reverses the endocavinoid system in the brain, the same system that creates "the munchies" when people smoke marijuana. Early results have been excellent, but industry watchers expect that there will still be a huge patient pool for bariatric surgery.