The use of transoral outlet reduction endoscopy to manage weight regain after gastric bypass: A comparison of 2 endoscopic techniques

Feb. 05, 2021

Although Roux-en-Y gastric bypass (RYGB) is considered the most effective weight-loss intervention, it's estimated that over 40% of patients experience weight regain after this procedure. One of the most common factors contributing to weight regain is the enlargement of gastrojejunal stoma size, which reduces satiety and allows patients to increase the volume of food consumed in one meal.

Dilated gastrojejunal stoma can be treated with revisional bariatric surgery. However, this intervention is technically difficult, has a higher risk of associated adverse events than primary bariatric surgery and may limit the patient's options for future obesity interventions.

Transoral outlet reduction endoscopy (TORe) is a revisional therapy that can help manage weight regain after RYGB. During this procedure, an endoscopic suturing system is used to plicate and reduce the size of the gastrojejunal anastomosis. The goal is to delay gastric pouch emptying and enhance the sensation of satiety.

Performed on an outpatient basis, TORe has a superior safety profile when compared with revisional bariatric surgery. Mayo Clinic researchers recently conducted a systematic review and meta-analysis to examine the efficacy and safety of the two most commonly used techniques for performing TORe: full-thickness suturing plus argon plasma mucosal coagulation (ft-TORe) and argon plasma mucosal coagulation (APMC-TORe) alone. Results of the meta-analysis were published in Gastrointestinal Endoscopy in 2020.


To conduct the analysis, Mayo Clinic researchers performed a literature search for studies evaluating TORe that were published during or before 2020.Their search focused on multiple outcomes of interest, including:

  • Percentage of total body weight loss (%TBWL), measured at three, six and 12 months after TORe
  • Pre- and post-gastrojejunal anastomosis (GJA) diameter
  • GJA change
  • Adverse events

The researchers analyzed pooled effect estimates using a random-effects model and conducted meta-regression to identify associations between GJA diameter and weight loss. They also performed a comparative analysis of TORe versus TORe with gastroplasty.

Of the 16 studies included in the researchers' analysis, nine involved ft-TORe (n = 737) and seven involved APMC-TORe (n = 888). In these studies, APMC-TORe was performed as a series of sessions (with the mean number of sessions ranging from 1.2 to 3), whereas ft-TORe was mostly performed as a single session.


Percentage TBWL in the ft-TORe treatment group:

  • 8%, with 95% confidence interval (CI), 6.3% to 9.7%, at three months
  • 9.5%, with 95% CI, 8.1% to 11.0%, at six months
  • 5.8%, with 95% CI, 4.3% to 7.1%, at 12 months

Percentage TBWL in the APMC-TORe treatment group:

  • 9.0%, with 95% CI, 4.1% to 13.9%, at three months
  • 10.2%, with 95% CI, 8.4% to 12.1%, at six months
  • 9.5%, with 95% CI, 5.7% to 13.2%, at 12 months

GJA diameter and weight loss in the ft-TORe treatment group

The researchers identified no significant association between pre-TORe GJA diameter, post-TORe GJA diameter, or GJA diameter change and %TBWL at six months (P = .45, .08 and .06, respectively). They did note a trend for greater weight loss with greater decrease in post-TORe GJA diameter and GJA diameter change.

GJA diameter and weight loss in the APMC-TORe treatment group

The analysis suggests that larger pre-TORe GJA diameter and smaller post-TORe GJA diameter are associated with a higher %TBWL at six months (P < 0.001 and 0.04, respectively). Additionally, greater change in GJA diameter is associated with greater %TBWL at six months (P < 0.001).

Adverse events

The researchers noted that there were no mortalities associated with either procedure. Only one severe adverse event occurred after APMC-TORe, and none occurred after ft-TORe. Stricture formation was the most common adverse event, occurring in 3.3% of patients after ft-TORe and in 4.8% of patients after APMC-TORe, meta-regression of P = 0.38. All strictures were successfully treated using endoscopic dilation or conservative treatment.


Overall, this meta-analysis demonstrated that TORe has excellent safety with good outcomes.

"Both ft-TORe and APMC-TORe can offer significant, sustained weight-loss outcomes, with a high safety profile," explains Barham K. Abu Dayyeh, M.D., M.P.H., senior author of the article in Gastrointestinal Endoscopy and a gastroenterologist who specializes in bariatric and metabolic endoscopy at Mayo Clinic in Rochester, Minnesota. "The other key point to emphasize is that smaller GJA diameter and greater GJA reduction are correlated with greater weight loss after TORe."

Given that both techniques are considered standard of care, Dr. Abu Dayyeh advises that when attempting to individualize the treatment approach for each patient, one should consider the following critical factors: the endoscopist's level of experience, the learning curve required for these techniques, institutional preference, available resources, any procedural costs, and anesthesia- or sedation-related costs.

"Given that APMC-TORe requires repeat endoscopic procedures, the cost is a relevant discussion point in some countries," explains Dr. Abu Dayyeh. "At Mayo Clinic, a single endoscopy is more costly than the endoscopic suturing device itself, and thus APMC-TORe with repeated sessions could pose a significant cost burden when compared with ft-TORe. On the other hand, APMC is less technically demanding and more universally available. At Mayo Clinic, we offer both techniques to our patients. In addition to the above-mentioned factors, we also consider the gastrojejunal anastomosis size and the gastric pouch volume."

Dr. Abu Dayyeh notes that ft-TORe is more suitable for those patients with a larger gastrojejunal anastomosis or a larger gastric pouch that allows the endoscopist to effectively reduce the gastrojejunal anastomosis and perform a gastroplasty for pouch reduction within a single session.

Next steps

When asked what the future holds for this field, Dr. Abu Dayyeh explains that the next phase of research should focus on refining the TORe technique and offering personalized treatment approaches. "Our group is comparing the effect of two different approaches on weight loss — TORe alone versus TORe plus gastroplasty in patients with enlarged gastric pouch sizes. To advance our ability to individualize treatment, future studies should also investigate the performance of each technique in different GJA diameters."

For more information

Jaruvongvanich V, et al. Endoscopic full-thickness suturing plus argon plasma mucosal coagulation versus argon plasma mucosal coagulation alone for weight regain after gastric bypass: A systematic review and meta-analysis. Gastrointestinal Endoscopy. 2020;92:1164.