Endoscopic management of obesity
Plication and suturing
Currently, there are two endoscopic devices that are approved for the general indication of tissue apposition. These include the Incisionless Operating Platform (IOP) (USGI Medical, San Clemente, Calif.) and the Overstitch endoscopic suturing system (Apollo Endosurgery, Austin, Tex.). These devices are used to remodel the stomach to create a sleeve-like structure to induce weight loss.
The IOP system consists of a transport, which is a 54-Fr flexible endoscope. It consists of four working channels that accommodate a G-Prox (for tissue approximation), a G-Lix (for tissue grasping), and an ultrathin endoscope (for visualization). In April 2008, Horgan performed the first-in-human primary obesity surgery endoluminal (POSE) procedure in Argentina. The procedure involves the use of the IOP system to place plications primarily in the fundus to modify gastric accommodation.21 The U.S. pivotal trial (ESSENTIAL trial) including 332 subjects (221 POSE arm versus 111 sham arm) demonstrated 5.0% TWL in the POSE group compared with 1.4% in the sham group at 12 months based on ITT analysis.22 A European multicenter randomized controlled trial (MILEPOST trial) including 44 subjects (34 POSE arm versus 10 non-sham control arm) demonstrated 13.0% TWL in the POSE group compared with 5.3% TWL in the control group at 12 months.23 A recent meta-analysis including five studies with 586 subjects showed pooled weight loss of 13.2% at 12-15 months following POSE with a pooled serious adverse event rate of 3.2%.24 These included extraluminal bleeding, minor bleeding at the suture site, hepatic abscess, chest pain, nausea, vomiting, and abdominal pain. A distal POSE procedure with a new plication pattern focusing on the gastric body to augment the effect on gastric emptying has also been described.25
The Overstitch is an endoscopic suturing device that is mounted on a double-channel endoscope. At the tip of the scope, there is a curved suture arm and an anchor exchange that allow the needle to pass back and forth to perform full-thickness bites. The tissue helix may also be placed through the second channel to grasp tissue. In April 2012, Thompson performed the first-in-human endoscopic sutured/sleeve gastroplasty (ESG) procedure in India, which was published together with cases performed in Panama and the Dominican Republic.26-28 This procedure involves the use of the Overstitch device to place several sets of running sutures along the greater curvature of the stomach to create a sleeve-like structure. It is thought to delay gastric emptying and therefore increase satiety.29 The largest multicenter retrospective study including 248 patients demonstrated 18.6% TWL at 2 years with 2% SAE rate including perigastric fluid collections, extraluminal hemorrhage, pulmonary embolism, pneumoperitoneum, and pneumothorax.30
Aspiration therapy
Aspiration therapy (AT; Aspire Bariatrics, King of Prussia, Pa.) allows patients to remove 25%-30% of ingested calories at approximately 30 minutes after meals. AT consists of an A-tube, which is a 26-Fr gastrostomy tube with a 15-cm fenestrated drainage catheter placed endoscopically via a standard pull technique. At 1-2 weeks after A-tube placement, the tube is cut down to the skin and connected to the port prior to aspiration. AT is approved for patients with a BMI of 35-55 kg/m2.31 The U.S. pivotal trial (PATHWAY trial) including 207 subjects (137 AT arm versus 70 non-sham control arm) demonstrated 12.1% TWL in the AT group compared to 3.5% in the control group at 12 months based on ITT analysis. The SAE rate was 3.6% including severe abdominal pain, peritonitis, prepyloric ulcer, and A-tube replacement due to skin-port malfunction.32
Transpyloric shuttle
The transpyloric shuttle (TPS; BAROnova, Goleta, Calif.) consists of a spherical bulb that is attached to a smaller cylindrical bulb by a flexible tether. It is placed and removed endoscopically at 6 months. TPS resides across the pylorus creating intermittent obstruction that may result in delayed gastric emptying. A pilot study including 20 patients demonstrated 14.5% TWL at 6 months.33 The U.S. pivotal trial (ENDObesity II trial) was recently completed and the data are being reviewed by the FDA.
Revision for weight regain following bariatric surgery
Weight regain is common following RYGB34,35 and can be associated with dilation of the gastrojejunal anastomosis (GJA).36 Several procedures have been developed to treat this condition by focusing on reduction of GJA size and are available in the United States (Figure 2). These procedures have level I evidence supporting their use and include transoral outlet reduction (TORe) and restorative obesity surgery endoluminal (ROSE).37 TORe involves the use of the Overstitch to place sutures at the GJA. At 1 year, patients had 8.4% TWL with improvement in comorbidities.38 Weight loss remained significant up to 3-5 years.39,40 The modern ROSE procedure utilizes the IOP system to place plications at the GJA and distal gastric pouch following argon plasma coagulation (APC). A small series showed 12.4% TWL at 6 months.41 APC is also currently being investigated as a standalone therapy for weight regain in this population.
