Transoral Outlet Reduction (TORe) Explained: A Complete Patient Guide

Table of Contents

1. What Is Endoscopic Revision?
2. Why Weight Comes Back: The Anatomy Problem
3. Anastomotic Dilation After Gastric Bypass
4. Sleeve Dilation After Sleeve Gastrectomy
5. TORe: The Procedure Step by Step
6. Argon Plasma Coagulation: How It Works
7. Full-Thickness Endoscopic Suturing
8. Weight Loss Results After TORe
9. Revisional Endoscopic Sleeve Gastroplasty
10. Who Is the Right Candidate
11. Who Is Not a Good Candidate
12. Risks and Complications
13. The Honest Limitations: Durability and Repeat Procedures
14. Endoscopic Revision vs. Surgical Revision
15. The Decision Framework: Medication vs. Endoscopy vs. Surgery
16. Combining Endoscopic Revision with GLP-1 Medications
17. What to Expect Before, During, and After the Procedure
18. FAQ
19. People Also Ask
20. Endoscopic Revision by the Numbers
21. Key Takeaways

Introduction

Most patients who regain weight after bariatric surgery believe they have two options: live with it or have another major operation.

They are wrong. There is a middle option that most patients have never heard of.

Endoscopic revision is a procedure performed entirely through the mouth. No abdominal incisions. No staple lines on the skin. No hospital stay. A flexible endoscope is passed through the throat, and specialized instruments are used to tighten a stretched connection or reduce a dilated sleeve from the inside.

For the right patient, it produces meaningful weight loss with a fraction of the risk of surgical revision. For the wrong patient, it is a waste of time and money. Understanding the difference is everything.

Weight regain after bariatric surgery is common. It is not a sign of failure. It is the natural history of a chronic disease. A registry of over 145,000 bariatric patients found that approximately 4 percent required a second procedure within 10 years. Other studies report that 20 to 30 percent of patients experience clinically significant weight regain. The question is never whether regain happens. The question is what to do about it.

This guide covers every endoscopic revision option available today: how each procedure works, the real outcomes data, the honest limitations, who is the right candidate, who is not, how endoscopic revision compares to surgical revision, and how to decide which path is right.

What Is Endoscopic Revision?

Endoscopic revision refers to any procedure performed through the mouth using a flexible endoscope to treat weight regain or inadequate weight loss after bariatric surgery. No abdominal incisions are made. The instruments are passed through the working channel of the endoscope or alongside it.

The two main categories are:

Transoral outlet reduction (TORe) for gastric bypass patients. This targets a dilated gastrojejunal anastomosis, the connection between the gastric pouch and the small intestine. The goal is to reduce the diameter of the opening back to approximately 10 to 12 millimeters, restoring the restriction that was lost over time.

Revisional endoscopic sleeve gastroplasty (ESG) for sleeve patients. This targets a dilated sleeve gastrectomy. Full-thickness sutures are placed along the stretched sleeve to reduce its volume and restore restriction.

Both procedures are performed under sedation or general anesthesia, typically take 45 to 90 minutes, and most patients are discharged the same day.

Why Weight Comes Back: The Anatomy Problem

Before understanding the fix, it is essential to understand what broke.

Weight regain after bariatric surgery occurs through two pathways: mechanical and metabolic. Endoscopic revision targets the mechanical pathway.

The mechanical pathway involves physical changes to the surgical anatomy. After gastric bypass, the gastrojejunal anastomosis can dilate. After sleeve gastrectomy, the sleeve itself can stretch. In both cases, the result is the same: the patient can eat larger portions without feeling full, and the restriction that made the surgery effective gradually fades.

The metabolic pathway involves hormonal changes. Ghrelin rebounds. Leptin resistance returns. Resting metabolic rate decreases. The hormonal advantage that surgery provided erodes over time. This pathway is not addressed by endoscopic revision. It is addressed by GLP-1 receptor agonists and other medications.

Most patients who regain weight have elements of both pathways, compounded by behavioral factors such as emotional eating, grazing, and reduced physical activity. A thorough workup is essential to determine which pathway is dominant, because the treatment depends entirely on the mechanism.

Anastomotic Dilation After Gastric Bypass

After Roux-en-Y gastric bypass, the gastrojejunal anastomosis is created at approximately 10 to 12 millimeters in diameter. This narrow opening is roughly the size of a dime. It creates restriction by slowing the passage of food from the pouch into the small intestine, allowing the patient to feel full on small portions.

Over time, this opening can stretch to 20, 25, or even 30 millimeters or more. When this happens, food passes through the pouch too quickly. The patient never achieves the sensation of fullness that the surgery was designed to create. Meal capacity increases. Hunger returns. And weight regain follows.

Anastomotic dilation is a mechanical, measurable, objective finding on upper endoscopy. It is not a behavioral failure. It is tissue remodeling over time. And it is the primary target of the TORe procedure.

Sleeve Dilation After Sleeve Gastrectomy

After sleeve gastrectomy, the stomach is reduced to a narrow tube that holds approximately 3 to 4 ounces. Over time, this tube can stretch.

A prospective study using 3D CT volumetry found that 61 percent of sleeve patients experienced measurable sleeve dilation within the first year after surgery. The gastric tube itself was responsible for 91 percent of the volume increase.

A separate study found a significant inverse relationship between sleeve volume and weight loss. Patients with a residual gastric volume above 180 milliliters had significantly lower excess weight loss than those below that threshold: 32 percent versus 52 percent.

Another prospective study confirmed that the amount of weight regain correlated directly with residual gastric volume on CT scan and with the distance between the pylorus and the beginning of the staple line.

Sleeve dilation is the target of revisional endoscopic sleeve gastroplasty, which uses sutures placed through the mouth to reduce the volume of the stretched sleeve.

TORe: The Procedure Step by Step

TORe stands for transoral outlet reduction. Transoral means through the mouth. Outlet refers to the gastrojejunal anastomosis. Reduction means making it smaller.

The procedure is performed under sedation or general anesthesia. A flexible endoscope is passed through the mouth, down the esophagus, and into the gastric pouch. The anastomosis is directly visualized and measured.

Step 1: Argon plasma coagulation (APC). A probe is passed through the endoscope that delivers a beam of ionized argon gas to the mucosal tissue surrounding the dilated anastomosis. This creates controlled, superficial thermal burns. As the tissue heals, it scars and contracts, beginning the process of reducing the diameter of the opening.

Step 2: Full-thickness endoscopic suturing. A specialized suturing device is passed through the endoscope. Stitches are placed through the full thickness of the tissue around the anastomosis, physically cinching the opening closed. The goal is to reduce the diameter back to approximately 10 to 12 millimeters.

The entire procedure takes 45 to 90 minutes. There are no abdominal incisions. Most patients are discharged the same day. Recovery involves a short liquid diet phase followed by gradual advancement to solid food, similar to the staged progression after the original surgery.

Argon Plasma Coagulation: How It Works

Argon plasma coagulation is a non-contact thermal ablation technique. The argon gas is ionized by a high-frequency electrical current, creating a plasma beam that is directed at the target tissue. The beam ablates the superficial mucosal layer without penetrating deeply into the wall, making it safer than direct cautery.

The controlled burns create an inflammatory response. As the tissue heals, fibrosis (scarring) occurs, causing the tissue to contract. This contraction reduces the diameter of the anastomosis.

APC can be used alone or in combination with endoscopic suturing. A randomized controlled trial compared APC alone versus APC plus endoscopic suturing and found that both groups achieved approximately 7.5 to 8.3 percent total body weight loss at 12 months, with no significant difference between the two approaches.

Some endoscopists perform APC as a standalone procedure in patients with mild dilation, reserving the addition of suturing for patients with more significant dilation or those who do not respond to APC alone.

Full-Thickness Endoscopic Suturing

The endoscopic suturing device is the key instrument in TORe. It is passed through the mouth alongside or through the endoscope and allows the operator to place full-thickness stitches through the tissue surrounding the anastomosis.

Full-thickness means the suture passes through all layers of the tissue wall, not just the superficial mucosa. This creates a stronger, more durable closure than superficial suturing techniques.

The stitches are placed in a pattern that physically narrows the opening. Multiple stitches are typically placed to achieve the target diameter of 10 to 12 millimeters. The sutures are made of a non-absorbable material, meaning they are designed to remain in place permanently.

A modified technique described in the literature involves performing endoscopic submucosal dissection (ESD) before suturing. ESD removes the superficial mucosal layer, exposing the deeper tissue layers and allowing the sutures to create a stronger scar. This modified technique achieved 12.1 percent total weight loss at 12 months, significantly greater than standard TORe.

Weight Loss Results After TORe

The data on TORe outcomes are drawn from multiple studies:

• A meta-analysis of over 1,100 patients found a mean total body weight loss of 8.9 percent at 12 months.
• A modified technique using endoscopic submucosal dissection plus suturing achieved 12.1 percent total weight loss at 12 months.
• A randomized controlled trial comparing APC alone versus APC plus suturing found approximately 7.5 to 8.3 percent total body weight loss at 12 months in both groups.

For context, a 250-pound patient losing 8.9 percent of total body weight loses approximately 22 pounds. A 300-pound patient loses approximately 27 pounds.

These results are modest compared to surgical revision. Conversion from sleeve to gastric bypass produces 23 to 35 percent additional total weight loss. Conversion to SADI-S produces even more. TORe produces roughly one-quarter to one-third of the weight loss that surgical revision achieves.

However, the risk profile is dramatically different. The serious adverse event rate after TORe is approximately 1 to 2 percent. After surgical revision, it is 5 to 21 percent. Readmission after surgical revision is 4.8 percent versus 2.9 percent for primary surgery. Reoperation is 2.4 percent versus 1.0 percent.

The question is not which produces more weight loss. The question is which produces the right amount of weight loss for the right patient at the right level of risk.

Revisional Endoscopic Sleeve Gastroplasty

Endoscopic revision is not limited to bypass patients. For sleeve patients with documented dilation, revisional endoscopic sleeve gastroplasty (ESG) is an emerging technique.

The procedure uses a full-thickness endoscopic suturing device passed through the mouth. A series of stitches are placed along the dilated sleeve, creating plications (folds) that reduce the internal volume and restore restriction. The technique is similar to primary ESG (endoscopic sleeve gastroplasty performed on a virgin stomach) but is applied to a previously stapled sleeve.

Multicenter data show 15.7 percent total weight loss at 12 months. This is notably higher than the 8.9 percent achieved by TORe for bypass patients.

The procedure is performed under general anesthesia, typically takes 60 to 90 minutes, and patients are usually discharged the same day or after one overnight observation.

This technique is still in its early evidence phase. Most published data come from single-center or small multicenter series. Long-term durability data beyond 12 to 18 months are limited. However, for sleeve patients who wish to avoid conversion to gastric bypass or duodenal switch, revisional ESG represents a promising minimally invasive alternative.

Who Is the Right Candidate

The ideal candidate for endoscopic revision has four characteristics:

1. Moderate weight regain. Typically 15 to 25 percent above the lowest weight achieved after surgery. Patients with massive regain (40 to 60 percent above nadir) generally need the metabolic power of surgical revision.
2. A clearly dilated anastomosis or sleeve on endoscopy. If the anatomy looks intact and the opening or sleeve is still at its original dimensions, the problem is not mechanical. It is hormonal or behavioral. Endoscopic revision will not fix a hormonal or behavioral problem.
3. No major anatomic failure requiring surgical correction. If there is a gastrogastric fistula, a significantly dilated pouch, a structural problem requiring reconstruction, or refractory GERD after sleeve, endoscopic revision is not sufficient.
4. A preference to avoid another surgery. Some patients are not candidates for surgical revision due to medical comorbidities. Others simply do not want another operation. For these patients, endoscopic revision offers a real, evidence-based alternative.

Who Is Not a Good Candidate

Endoscopic revision is not appropriate for every patient with weight regain. The following patients are generally better served by surgical revision or other approaches:

• Patients with severe weight regain (more than 30 to 40 percent above nadir). The modest weight loss produced by endoscopic revision is unlikely to be sufficient.
• Patients with no anatomic target. If the anastomosis is not dilated and the sleeve is not stretched, there is nothing for the endoscopic procedure to fix. The problem is hormonal or behavioral and should be addressed with GLP-1 medications, nutritional counseling, and behavioral support.
• Patients with refractory GERD after sleeve. These patients need conversion to gastric bypass, which resolves reflux in 80 to 94 percent of cases. Endoscopic revision does not address reflux.
• Patients with a gastrogastric fistula after bypass. This requires surgical repair.
• Patients with significant pouch dilation after bypass. TORe targets the anastomosis, not the pouch. If the pouch itself is significantly enlarged, surgical pouch revision may be needed.
• Patients with Barrett's esophagus after sleeve. These patients need conversion to bypass for esophageal protection. Endoscopic revision does not address Barrett's.

Risks and Complications

Endoscopic revision has a favorable safety profile compared to surgical revision, but it is not risk-free.

Serious adverse events occur in approximately 1 to 2 percent of TORe procedures. This compares to 5 to 21 percent for surgical revision.

Stricture formation is the most common complication, occurring in approximately 3 to 5 percent of patients. The sutures can create an opening that is too tight, causing difficulty swallowing, food getting stuck, or vomiting. Strictures are treatable with endoscopic balloon dilation, which is a brief outpatient procedure.

Bleeding can occur at the suture or APC sites but is typically self-limited or treatable endoscopically.

Perforation is exceedingly rare but is a theoretical risk of any full-thickness suturing procedure.

Pain and nausea are common in the first 24 to 48 hours after the procedure and are managed with medication.

Mortality is exceedingly rare. No deaths have been reported in the major TORe meta-analyses.

The Honest Limitations: Durability and Repeat Procedures

Durability is the biggest question mark surrounding endoscopic revision.

A systematic review found that endoscopic bariatric procedures resulted in modest and in some cases temporary weight loss. Some patients regain weight after the initial loss as sutures loosen or tissue stretches again over time.

Approximately 20 to 25 percent of patients may need a repeat endoscopic procedure or escalation to surgical revision.

Long-term data beyond 12 to 18 months are limited for most endoscopic revision techniques. The field is evolving rapidly, with newer techniques (such as the modified ESD plus suturing approach) showing improved durability, but definitive long-term outcomes data are still needed.

Insurance coverage remains inconsistent. Many insurers still consider endoscopic revision investigational. Coverage varies widely by plan and by region. This is changing as the evidence base grows, but it remains a barrier for some patients.

These limitations do not make endoscopic revision ineffective. They make it a tool with a specific role: moderate weight regain, clear anatomic target, favorable risk-benefit ratio. When used in the right patient, it delivers meaningful results. When used in the wrong patient, it delays the intervention that is actually needed.

Endoscopic Revision vs. Surgical Revision

Understanding the trade-offs between endoscopic and surgical revision is essential for making an informed decision.

Weight loss: Surgical revision produces 2 to 4 times more weight loss than endoscopic revision. Sleeve-to-bypass conversion produces 23 to 35 percent additional total weight loss. Sleeve-to-SADI-S produces even more. TORe produces approximately 8.9 percent total weight loss. Revisional ESG produces approximately 15.7 percent.

Complication rate: Endoscopic revision has a serious adverse event rate of 1 to 2 percent. Surgical revision has a complication rate of 5 to 21 percent, with readmission rates of 4.8 percent and reoperation rates of 2.4 percent.

Mortality: Both are very low. Surgical revision mortality ranges from 0.03 to 0.8 percent depending on the specific procedure. Endoscopic revision mortality is exceedingly rare.

Recovery: Endoscopic revision is same-day discharge with minimal recovery. Surgical revision requires 1 to 3 nights in the hospital and 2 to 4 weeks of recovery.

Durability: Surgical revision has stronger long-term durability data. Endoscopic revision durability beyond 12 to 18 months is uncertain.

GERD resolution: Surgical conversion to bypass resolves reflux in 80 to 94 percent of cases. Endoscopic revision does not address reflux.

A propensity-matched study comparing endoscopic and surgical revision found similar weight loss at 12 months with a significantly better safety profile for the endoscopic approach. However, surgical revision is expected to show greater durability and greater total weight loss at longer follow-up intervals.

The Decision Framework: Medication vs. Endoscopy vs. Surgery

The approach to weight regain after bariatric surgery should be stepwise, starting with the least invasive option and escalating as needed.

Step 1: Lifestyle optimization. Nutritional counseling, behavioral support, exercise, protein compliance, vitamin adherence, and follow-up attendance. Every patient starts here regardless of what comes next.

Step 2: Medical therapy. GLP-1 receptor agonists such as semaglutide or tirzepatide. These medications work on the same hormonal pathways that surgery targets. A meta-analysis found mean weight reductions of approximately 7 kg with liraglutide and significantly greater loss with semaglutide. A retrospective study found that GLP-1 medications reversed approximately two-thirds of post-bariatric weight regain. For patients with moderate regain driven primarily by hormonal rebound and behavioral factors, medication plus lifestyle changes may be sufficient.

Step 3: Endoscopic revision. For patients who have a clear anatomic target (dilated anastomosis or stretched sleeve) and moderate regain that has not responded to lifestyle and medication alone.

Step 4: Surgical revision. For patients with significant anatomic failure, severe regain, refractory reflux, Barrett's esophagus, or inadequate response to less invasive options.

The critical first step, before any of these decisions, is a proper workup. Upper endoscopy to evaluate the anatomy. Upper GI series or 3D CT volumetry to assess sleeve or pouch dimensions. Laboratory studies to identify nutritional deficiencies. Nutritional assessment. Psychological evaluation. The right treatment depends on the right diagnosis.

Patients in South Florida deciding between endoscopic and surgical options can see how revision evaluation works at our practice on the bariatric revision surgery in Miami page.

Combining Endoscopic Revision with GLP-1 Medications

Endoscopic revision and GLP-1 medications are not mutually exclusive. They can be combined to address both pathways of weight regain simultaneously.

TORe restores mechanical restriction by tightening the dilated anastomosis. GLP-1 medications restore hormonal suppression of hunger by activating GLP-1 receptors in the brain and gut.

Together, they address the mechanical pathway and the metabolic pathway at the same time. Early data on this combination are encouraging, though large-scale studies are still needed.

For patients who undergo endoscopic revision and achieve good initial results but begin to plateau, adding a GLP-1 medication can extend and amplify the weight loss. This multimodal approach, combining anatomic correction with pharmacologic support, represents the future of weight regain management.

What to Expect Before, During, and After the Procedure

Before the procedure: A comprehensive workup including upper endoscopy, labs, imaging, nutritional assessment, and a discussion of goals and expectations. You will follow a clear liquid diet for 24 hours before the procedure. Certain medications may need to be held.

During the procedure: You will be sedated or under general anesthesia. The endoscope is passed through the mouth. You will not feel anything during the procedure. It takes approximately 45 to 90 minutes.

After the procedure: Most patients are discharged the same day. Expect mild to moderate throat discomfort, nausea, and abdominal cramping for 24 to 48 hours. You will follow a staged diet progression: clear liquids for 1 to 2 days, full liquids for several days, then gradual advancement to pureed foods, soft foods, and regular solids over 2 to 4 weeks.

Follow-up: You will see your surgical team within 1 to 2 weeks after the procedure. Ongoing follow-up is essential to monitor weight loss, adjust medications if needed, and ensure the revision is holding.