CHICAGO, June 3 — Transoral methods for reducing gastric volume or bypassing the stomach altogether as treatment for obesity are gaining steam, several reports here indicated.
Endoscopic suturing procedures have produced losses of more than 60% of excess weight in obese teens with up to 18 months of follow-up, and up to 40% after nine months in adults, two researchers said here at Digestive Disease Week in separate presentations.
And yet a third researcher reported that an implanted plastic food bypass tube, extending from the base of the esophagus to 100 cm (about 40 inches) into the small intestine, led to excess weight losses averaging 40% in a 12-week pilot study.
All three researchers reported few or no complications and noted that the procedures can be reversed easily if that proves to be necessary.
One of the studies was a follow-up of preliminary findings reported at DDW last year by Roberto Fogel, M.D., of Mercy Hospital in Miami and Hospital de Clinicas in Caracas, Venezuela. (See DDW: Stomach Suturing Via Oral Route Reduces Teen Obesity)
At that time, Dr. Fogel had reported six-month results for 12 teens, ages 14 to 17. The teens had lost an average of 60% of their excess weight.
His endoscopic procedure stitches the stomach walls together to create a narrow tube-like passage from the esophagus to the duodenum.
His new report covered 21 adolescents, 13 to 17 years old, with initial mean body mass index (BMI) of 36.2 before the procedure. Follow-up in this group ranged from six to 18 months.
Among all the teen patients, mean excess weight loss at six months was 67.3% (SD 15.6%).
For 15 patients with one year of follow-up and eight with 18 months of follow-up, excess weight loss averaged 63.8% (SD 16.7%) and 58.8% (SD 17.5%), respectively.
Christopher Thompson, M.D., of Brigham and Women’s Hospital in Boston, reported comparable findings with another endoscopic suturing procedure performed in 18 adults.
These patients averaged 41 years of age and had a baseline BMI of 38.7.
Dr. Thompson reported the following mean excess weight losses at various follow-up exams:
Three months (17 patients) 30.0%
Six months (15 patients) 30.3%
Nine months (seven patients) 34.2%
Although these percentages are half those seen in Dr. Fogel’s study of teens, the two researchers agreed that they actually reflect similar clinical effects. The apparent disparity is an artifact of how excess weight is calculated in teens versus adults.
The degree of weight loss in both studies is similar to that seen with Roux-en-Y bypass surgery in these populations, Drs. Fogel and Thompson agreed.
Dr. Fogel said his procedure takes about 40 minutes; about two hours was the average reported by Dr. Thompson, whose procedure involves an investigational full-thickness suturing device.
Another approach was reported by Paul Swain, M.D., of Imperial College London.
He presented findings from an initial clinical study of a polyethylene tube with a proprietary biocompatible coating.
The tube is anchored at the esophageal base with metal barbs at one end, and extends through the stomach about 100 cm into the small bowel, with similar anchors at the distal end.
Consequently, food passes directly from the esophagus into the intestine.
“People don’t need a stomach,” Dr. Swain said, pointing out that patients survive readily following total gastrectomy.
He said the 12-patient pilot study was primarily to assess safety. It was implanted for 12 weeks and then removed.
Mean excess weight loss was 40% at the time the devices were removed. Mean BMI at baseline ranged from 37 to 50.
“All tissue anchors remained in place and no spontaneous detachments occurred,” Dr. Swain reported. There were no serious complications associated with the device or its removal.
He said a six-month study was now underway and appeared to be showing similar results.
Dr. Fogel said the chief concern about devices in the GI tract is that they migrate. Bleeding from the anchors is another problem, he said.
“The best use [of devices] may be to use them for a year before surgery so that patients lose weight,” he suggested.
He said extreme obesity often complicates endoscopic or other surgery. Using an implanted device to help patients slim down before a more definitive procedure is performed may be the optimal approach, Dr. Fogel suggested.
Kai Nishi, M.D., of Cedars-Sinai Medical Center in Los Angeles, said it was currently unclear which type of transoral gastric reduction might be preferable.
Dr. Nishi is an investigator on a large clinical study of a procedure called Toga, which uses a proprietary transoral stapling device to reduce stomach volume.
He showed a video of the procedure, but indicated that results would not be available until next year.
Referring to this and the other studies reported at DDW, he said, “It will take these trials to determine which of these is optimal for safety and efficacy.”
Dr. Thompson’s study was funded by Bard.
Dr. Thompson reported relationships with Bard, Boston Scientific, Covidien, Olympus America, Power Medical, USGI Medical, and Valentx.
Dr. Swain’s study was funded by Valentx.
Dr. Swain reported no conflicts of interest other than research support from Valentx.
No external support was reported for Dr. Fogel’s study.
Dr. Fogel reported a consulting relationship with Davol.
Dr. Nishi reported relationships with Ethicon and Allergan.
Primary source: Digestive Disease Week
Fogel R, et al “Trans-oral vertical gastroplasty as a viable treatment for childhood obesity — a study of 21 adolescents with up to 18 months of follow-up” DDW 2009; Abstract S1426.
Additional source: Digestive Disease Week
Thompson C, et al “Transoral gastric volume reduction as an intervention for weight management (TRIM) multicenter feasibility study: a report of early outcomes” DDW 2009; Abstract M1259.