endoluminal therapy

Endoscopic Weight Loss Options & Endoluminal Therapy

April 18, 2016

It is clear that weight loss surgery (WLS) is the treatment of choice for obesity and its associated diseases such as diabetes. Patients are typically able to achieve a sustained loss of 50-80% of excess body weight, with robust improvements in high blood pressure, diabetes, and obstructive sleep apnea.[1] However, WLS procedures such as the gastric bypass and sleeve gastrectomy are highly invasive, requiring inpatient hospital stays and carry the potential for complications and even death. Furthermore, these operations actually have a real failure rate: 20-30% of patients fail to achieve adequate weight loss, and an equal percentage of patients will suffer from significant weight gain over time essentially negating the effects of the operation.[2]

Due in part to these risks, the availability of operative services, and cost, only 1% of eligible patients will ultimately utilize WLS.[3] Therefore, there is a huge unmet need for safe, minimally invasive, and cost-effective treatments for obesity. This article will examine the emerging role of endoscopic weight loss options, the scientific evidence supporting endoluminal therapy, and considerations for patients contemplating these procedures.

Why Endoscopy?

Many of you have likely undergone an endoscopy, either for investigation of stomach symptoms, reflux or for preoperative assessment prior to WLS. Endoscopy involves the passage of a flexible tube with a camera and light, about the size of a finger, into the mouth, down the esophagus, and into the stomach. Devices can be passed through the scope to take biopsies or remove lesions such as polyps. Endoscopies are typically performed using intravenous sedatives and can be performed as an outpatient procedure (come-and-go the same day).

Due to recent advances in endoscopic technology, we are entering an exciting new era of endoscopic weight loss therapy. Several novel techniques and devices have been developed that provide new endoscopic options both as primary treatments for weight loss and as treatments for weight gain following WLS. These techniques promise safer treatments with less cost and recovery time than traditional WLS, and may be offered to more patients who may not qualify for WLS or who are unwilling to undergo an operation.

Intragastric Balloons (IGB)

The oldest and most well studied endoscopic technique for weight loss is the placement of what amounts to a water balloon in the stomach.

These devices work by occupying space in the stomach which may activate stretch receptors, delay stomach emptying and activate satiety-inducing hormones leading to increased satiety (fullness). These devices were first introduced over thirty years ago, but were withdrawn from the market due to concerns over device failure and complications.[4]

Since then, intragastric balloons (IGB) have been redesigned and studied extensively, primarily overseas. Two commercially available IGB were recently approved by the FDA in 2015: the Orbera (Apollo Endosurgery, Austin, TX) and the ReShape Duo (ReShape Medical, Inc, San Clemente, CA). Previous versions of the Orbera have been available outside the United States for decades, while the ReShape Duo balloon, consisting of two balloons attached together, is a newly approved device.

IGB are placed endoscopically and inflated with sterile saline to the indicated volume. The devices are intended for temporary placement and are typically removed endoscopically at a predetermined interval, usually six months. Therefore, you will need to undergo two endoscopies, though these are performed in the outpatient setting. IGB cannot be placed if you have a large hiatal hernia, inflammation of the esophagus or stomach, or ulcer disease. Most patients will experience nausea and/or discomfort during the first few days after placement as the stomach adjusts to the balloon, therefore, your provider will furnish you with anti-nausea and pain medications. Generally, most patients will tolerate the balloon after this initial period.

IGB placement is the most extensively studied endoscopic weight loss procedure. A meta-analysis (combination study) of 15 studies including 3,608 patients demonstrated an average total body weight loss of 12.2%, excess weight loss (EWL) of 32.1 % and reduction in BMI of 5.7 kg/m2 at balloon removal after 6 months.[5] IGB has also been shown to result in significant improvement in glycemia and insulin resistance (associated with diabetes), triglyceridemia (cholesterol levels) and fatty liver. The most commonly reported side effects include nausea and vomiting (8.6%), abdominal pain (5%), deflation and displacement (2.5%), gastroesophageal reflux (1.8%). Early removal of the device due to such complaints occurred in 4.6% of patients in this study.

A common question regarding this temporary device is how long the weight loss will last.

This was examined in a study including 474 patients. Using a threshold of 20% excess weight loss, 53%, 27%, and 23% of patients achieved this target at 12, 24, and 60 months of follow-up respectively. So while the percentage of patients maintaining weight loss decreases over time, balloon placement likely provides some patients with the necessary ‘boost’ to improve their lifestyle. We also know that participating in a behavior medication program and support group improves the amount and durability of weight loss.[6]

Endoscopic Sleeve Gastroplasty (ESG)

The ESG is a procedure that uses an endoscopic suturing device to recreate the anatomy of a surgical vertical sleeve gastrectomy (VSG). In a VSG, the stomach is stapled vertically so that a small stomach ‘tube’ is created and the majority of the stomach is removed from the flow of ingested food. This creates restriction, reducing that amount of food you can eat, and also alters satiety-inducing hormones.

In contrast to the VSG, the ESG utilizes an endoscopic suturing device to create the tube. This technique allows for an ‘incisionless operation’, potentially reducing complications, cost and recovery times compared with the surgical approach.

The ESG is a relatively new procedure though data are encouraging. In a Spanish study of 50 patients, the mean percent total body weight lost was 19.0 ± 10.8 and BMI reduced from 37.7 ± 4.6 to 30.9 ± 5.1 kg/m2 at 1 year.[7] The procedure was completed in about an hour, and all patients were discharged home within 24 hours. There were no serious side effects reported. A smaller U.S. study demonstrated an average weight loss of 14.1 kg, with 30% EWL and a 5.5 Kg/m2 drop in BMI at 6 months.[8] Based on these results, ESG may be a viable alternative to surgical sleeve gastrectomy, though the long term durability of weight loss is still under investigation.

Gastric Bypass Revision

Weight regain following Roux-En-Y Gastric Bypass is an increasingly recognized and frustrating problem, though it is rarely discussed amongst patients and providers alike.

More than 20% of patients will regain significant amounts of weight, which may lead to the return of diseases such as hypertension, diabetes and joint disease while negatively impacting patients’ quality of life and self-esteem. In fact, many of my patients feel that they have ‘failed’ and feel stigmatized for ‘wasting’ the operation. However, we now know that dilation (stretching) of the surgically created gastric pouch and stoma (outlet of the pouch) are independently associated with weight gain.[9,10] Most commonly, patients will complain of being able to eat more food at meals (often they say they can eat ‘like a normal person’), or that they are increasingly hungry between meals and end up grazing throughout the day.

While revision operations are effective at re-establishing weight loss, they are associated with increased risks compared with the original operation, therefore, patients and surgeons are often reluctant to pursue this option. Thus, endoscopic suturing (similar to that used for ESG) has been explored as a treatment of weight regain for over a decade. Several studies have been published on this technique, including a randomized, sham-controlled study (the most rigorous study design). Nearly all patients achieve weight stabilization (their weight gain stops), while most will lose 20 – 50% of their excess weight.[11,12,13] The procedure is well-tolerated, and most patients are discharged home within 24 hours, and return to work within a couple days.

While endoscopic Transoral Outlet Reduction (TORe) can improve satiety and help patients eat less, it is best seen as a tool to help reinvigorate weight loss, rather than a second operation per se.

I encourage all patients to reconnect with support groups, visit with a dietician, and refocus on establishing healthy lifestyle choices. In addition to the gastric bypass, vertical sleeve gastrectomy surgeries can also be modified endoscopically, though there is less available data on this technique.

Promising New Strategies Under Investigation

There are several new and interesting techniques in various stages of development and study that have yet to be approved in the U.S. These explore new strategies to achieve weight loss and combat diabetes.

POSE procedure (Primary Obesity Surgery Endoscopic)

The best studied of these is the POSE procedure (Primary Obesity Surgery Endoscopic) which involves the placement of metal mesh anchors that create plications in the stomach to limit its capacity and slow stomach emptying to increase satiety. This procedure has been performed and studied for several years. The largest study to date out of Europe included 147 patients who lost nearly half of their excess weight.[15] A multicenter U.S. study has concluded, and FDA approval is anticipated.

Aspiration Therapy

This is a new therapy designed to enhance weight loss by removing food immediately after meals. The AspireAssist Device (Aspire Bariatrics, King of Prussia, Pennsylvania, USA) is a discrete large caliber tube that is placed endoscopically extending from the skin to the stomach. Following a meal, a patient will attach a proprietary siphon to remove a portion of the ingested food, thus leading to reduction in caloric intake. While this technique may sound less than palatable, it has been shown to be effective. A U.S. multicenter study has completed enrollment, and the results will be forwarded to the FDA for approval in the near future.

Duodenal Mucosal Resurfacing

This is a technique that uses a warm water infusion within a balloon placed in the duodenum (the part of the intestine immediately below the stomach) to essentially burn the superficial layer (mucosa) of the bowel. This leads to hormonal changes that can counteract diabetes. Another clever innovation is the endoscopic placement of self-assembling magnets (Incisionless Anastomosis System, GI Windows Inc, Bridgewater, MA) to gradually create a gastric bypass within the body without the need for surgery. This has been studied in animals, and the first human cases are being performed in Europe. A third promising therapy is the Transpyloric Shuttle (Baronova Inc, Goleta, California, USA). The device consists of two spherical bulbs connected by a flexible catheter that is placed in the stomach, resulting in intermittent blockage of stomach emptying and increased fullness. A U.S. multicenter is being planned. As one can see, we are experiencing a boom in endoscopic technologies, though we will have to await solid scientific evidence before we can embrace any of these new treatments.

Is Endoluminal Therapy For Me?

If you are considering endoscopic approaches to weight loss, there are several key considerations to take into account. Firstly, while some of these approaches have been studied for several years, many are still under investigation and require participation in clinical trials. In addition, these procedures often require specialized endoscopic skill, and finding an experienced and appropriately trained provider is recommended.

Secondly, despite all the published studies on these techniques, there is a paucity of data on the long-term outcomes beyond five or more years. While this does not mean that endoscopic therapy is not effective, it does highlight the relatively recent development of this field. Fortunately, most of these procedures are temporary or can be reversed, so that surgical treatments can be performed if necessary or desired. In my view, endoscopic therapy will occupy the (rather large) niche between medical therapy (supervised diet/exercise and medicines) and surgery. So it is reasonable to expect greater effectiveness compared with medicines (along with theoretically more risk), but less efficacy than that of surgery (with less risk). These therapies may be the first step for patients on their weight loss journey, their only treatment, or their last in the form of a revision procedure.

Finally, and perhaps most importantly, these procedures cannot replace surgery for those with extreme obesity, nor can they replace the appropriate practice of a healthy lifestyle and a support network. In fact, these procedures are only approved as part of a comprehensive weight loss program that includes group support, dietary counseling and exercise. As we know, there is no ‘magic pill’ for weight loss and this holds true for endoscopic therapies.

As I tell my patients, I can perform the procedure, but that is just the tool. You have to train – train your mind, train your attitude, train your body.

With the advent of endoscopic weight loss procedures, we are undoubtedly entering an exciting new era in the treatment of obesity and I am optimistic that as we continue to improve our techniques and technologies, so too will the lives our patients!


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  1. Deepinder Goyal, Stephen Kim, Eric Dutson, Yijun Chen, Joseph Pisegna, Rabindra Watson. Endoscopic Trans-Oral Outlet Reduction in Combination with Gastroplasty (TORe-G) is a Novel Technique that is Highly Efficacious and Safe for Weight Loss in Patients with Failed Roux-en-Y Gastric Bypass. American College of Gastroenterology Annual Meeting Oct 18, 2015. Honolulu, USA; Poster 186.
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Dr. Rabindra R. Watson serves as the bariatric endoscopist at the UCLA Center for Obesity and Metabolic Health (COMET) and is an assistant clinical professor of medicine for the Division of Digestive Diseases at the David Geffen School of Medicine at UCLA, where he is pursuing investigations in the emerging field of bariatric endoscopy.