Sleeve to OAGB Conversion

Sleeve gastrectomy is the most common weight-loss operation in the world. Long-term studies show that a meaningful share of sleeve patients eventually need a second operation. In one 10-year series, 30.7% of followed sleeve patients were converted to another procedure (Cooke et al., Obesity Surgery, 2026). The most common reasons are weight regain or not enough weight loss, followed by acid reflux (Kermansaravi et al., Scientific Reports, 2022). See Sleeve Gastrectomy and Revisional Bariatric Surgery for background.

Sleeve to one-anastomosis gastric bypass (OAGB) conversion turns the existing sleeve into a long, narrow gastric pouch. The pouch is divided from the lower stomach and joined to a loop of small intestine in a single connection (anastomosis). The bypassed segment, called the biliopancreatic limb, is usually set at 150–200 cm, and the limb length should be tailored to each patient. Longer limbs (over 200 cm) are linked to higher rates of nutritional deficiency (Jazaeri et al., Scientific Reports, 2025). Some surgeons measure the full small bowel during surgery and set the limb at about 30% of its length. In a 2026 cohort of 200 conversions, this tailored approach produced greater weight loss and far fewer micronutrient deficiencies (4% vs 26%) than a fixed 200 cm limb. Mild bile reflux was reported somewhat more often in the tailored group (Abosheisha et al., Journal of Gastrointestinal Surgery, 2026). More detail on the primary operation is on One-Anastomosis Gastric Bypass (OAGB/MGB).

Compared with converting to Roux-en-Y gastric bypass, OAGB gives more weight loss through a simpler operation. A 2026 meta-analysis of 1,556 patients found that conversion to OAGB produced 5.7% more total weight loss and took about 25 minutes less in the operating room. There were no significant differences in leak, bleeding, or marginal ulcer rates (Noel et al., Obesity Surgery, 2026). A separate meta-analysis that included a randomized trial found similar remission of diabetes, hypertension, and reflux and comparable complication rates between the two operations (Silva-Chavez et al., Obesity Surgery, 2025). In a 5-year series of sleeve-to-OAGB conversions, total weight loss peaked at 27.4% at 2 years and was 20.9% at 5 years. All patients had remission or improvement of diabetes, hypertension, high cholesterol, and sleep apnea at 1 year (Kermansaravi et al., Scientific Reports, 2022).

Reflux is the main trade-off. In the same 2026 meta-analysis, reflux resolved in 68.6% of patients after OAGB conversion and 80.6% after RYGB conversion. Beyond 2 years the gap widened to 66% vs 85%. New-onset reflux was more common after OAGB (6.3% vs 0.5%), although that difference did not reach statistical significance (Noel et al., Obesity Surgery, 2026). For this reason, OAGB conversion is usually reserved for weight regain without significant reflux (Cooke et al., Obesity Surgery, 2026). Patients with reflux are directed to Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion.

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The existing sleeve is evaluated and revised if necessary. A long, narrow gastric pouch is created. The small intestine is measured and connected to the pouch in a single-anastomosis loop. This configuration reduces calorie absorption, improves metabolic signaling, and enhances long-term weight regulation.

Benefits include strong metabolic improvement, excellent weight loss, reduced hunger, improved satiety, and durable long-term outcomes. OAGB is especially effective for patients with significant weight regain or metabolic disease after sleeve gastrectomy.

• Sleeve patients with weight regain or inadequate weight loss who have already tried nutrition counseling, behavioral support, and anti-obesity medication. This is the primary indication for OAGB conversion (Kermansaravi et al., Scientific Reports, 2022; Cooke et al., Obesity Surgery, 2026).

• Patients with no significant reflux, confirmed by testing. Upper endoscopy should show no erosive esophagitis or Barrett's esophagus. When symptoms are unclear, pH testing should confirm there is no abnormal acid exposure. This matters because a single-anastomosis bypass leaves room for bile to reach the pouch and esophagus (Noel et al., Obesity Surgery, 2026).

• Patients whose sleeve is a normal size. A sleeve that hasn't stretched won't be improved by tightening it. Adding a bypass treats what is actually driving the regain. If imaging shows a dilated sleeve or a retained fundus and you have no reflux, see Re-Sleeve Gastrectomy.

• Patients who want more weight loss than RYGB conversion typically gives, through one intestinal connection instead of two (Noel et al., Obesity Surgery, 2026; Silva-Chavez et al., Obesity Surgery, 2025).

• Patients whose type 2 diabetes or high blood pressure has returned. In pooled data on revisional OAGB, remission of diabetes and hypertension reached 78% and 75% at 5 years (Abu-Abeid et al., Obesity Surgery, 2022).

• Patients committed to lifelong vitamin supplements and lab monitoring. In long-term comparisons, nutritional deficiencies were more common after OAGB (20.0%) than after sleeve (12.0%), and marginal ulcers occurred in 7.7% of primary OAGB patients (Plamper et al., Journal of Gastrointestinal Surgery, 2023).

Who is usually better served by a different operation:

• Medically refractory reflux, erosive esophagitis, Barrett's esophagus, or a hiatal hernia. The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) suggests conversion to RYGB for refractory reflux after sleeve when BMI is over 35. SAGES also recommends repairing any hiatal hernia at the same operation (Kumar et al., SAGES Guidelines, 2025). The American Society for Metabolic and Bariatric Surgery (ASMBS) describes RYGB as the most effective treatment to date for post-sleeve reflux, with OAGB a promising alternative that still needs further validation (Vosburg et al., ASMBS, 2026). See Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion, Hiatal Hernia Repair After Sleeve Gastrectomy, and Gastric Bypass (Roux-en-Y) for GERD.

• Reflux with a lower BMI and preserved esophageal function. Magnetic sphincter augmentation may be reasonable (Kumar et al., SAGES Guidelines, 2025). See LINX Magnetic Sphincter Augmentation.

• Maximal weight loss as the top priority. In a network meta-analysis of revisions after sleeve, SADI-S ranked highest for weight loss, and complication rates were comparable (Małczak et al., Obesity Reviews, 2025). SADI-S also had significantly less bile reflux than OAGB (Ahmed et al., Obesity Surgery, 2024). See Sleeve to SADI-S Conversion and Sleeve to MagDI Conversion.

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The procedure is performed laparoscopically. The sleeve is inspected and revised if needed. A long gastric pouch is created, and the small intestine is connected to the pouch in a single-anastomosis configuration. Most patients go home the next day.

Risks include bleeding, leak, stricture, bile reflux, marginal ulcer, nutritional deficiencies, and weight regain if long-term habits are not maintained. Revisional surgery carries slightly higher risk due to scar tissue.

Days 1–3: hydration, ambulation, pain control. Week 1: liquids. Week 2: soft foods. Weeks 3–4: gradual return to normal routines. By 30 days: improved energy, reduced hunger, early metabolic improvements.

Patients typically experience strong metabolic improvement and steady fat loss over 12–18 months. OAGB offers more durable long-term results than sleeve gastrectomy alone.

More in Sleeve Gastrectomy Revisions

Related procedures: Sleeve Gastrectomy to Magnetic Duodeno-Ileostomy Conversion, Re-Sleeve Gastrectomy, Hiatal Hernia Repair After Sleeve Gastrectomy, Gastric Sleeve Stricture Management, Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion, Sleeve Gastrectomy to SADI-S Conversion. Related primary operations: Sleeve Gastrectomy, One-Anastomosis Gastric Bypass. For an overview of all options, see Revisional Bariatric Surgery.

Conditions treated: Weight Regain, Inadequate Weight Loss, Acid Reflux, Stomach Narrowing (Stricture) After Bariatric Surgery, Hiatal Hernia & Paraesophageal Hernia, Barrett’s Esophagus.

Which revision a sleeve patient receives should depend on the patient, not on habit. In the United States, about 81% of sleeve revisions are converted to Roux-en-Y gastric bypass (Crnkovic et al., Surgery for Obesity and Related Diseases, 2026). OAGB is endorsed by both the ASMBS and IFSO, and it is the third most commonly performed bariatric operation worldwide (Jazaeri et al., Scientific Reports, 2025). Yet it is offered at far fewer American centers. Every conversion also carries higher 30-day risk than a first operation (Dallal et al., Surgery for Obesity and Related Diseases, 2026). So the right choice matters, and so does the experience of the team carrying it out.

Dr. Nestor de la Cruz-Muñoz, MD, FACS, DABOM, is a board-certified surgeon and a diplomate of the American Board of Obesity Medicine, so he treats obesity both medically and surgically. He served for 10 years as a fellowship program director, training surgeons in revisional bariatric surgery and reoperative foregut surgery. His practice is also a referral center for reflux and hiatal hernia surgery. That matters here because whether you have reflux is the single most important factor in choosing between OAGB and RYGB.

His program offers every sleeve revision option in one place:

• Re-Sleeve Gastrectomy

• Sleeve Gastrectomy to Roux-en-Y Gastric Bypass Conversion

• Sleeve to OAGB Conversion

• Sleeve to SADI-S Conversion

• Sleeve to MagDI Conversion

• Hiatal Hernia Repair After Sleeve Gastrectomy

• LINX Magnetic Sphincter Augmentation

• Anti-obesity medication

Every evaluation includes:

• Upper endoscopy

• Reflux and esophageal function testing when indicated

• Imaging of the sleeve

• A nutritional baseline

During surgery, the biliopancreatic limb is tailored to the patient rather than set at one fixed length. If bile reflux develops after OAGB, it can be treated with a straightforward conversion to Roux-en-Y anatomy (see OAGB to Gastric Bypass Conversion), handled by the same team that performed your original revision.

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Dr. de la Cruz-Muñoz has more than 25 years in bariatric surgery and more than 9,000 bariatric operations behind him, a volume few surgeons reach. He uses that experience to decide whether a sleeve is best converted to OAGB or to another operation.

In a 5-year series of sleeve-to-OAGB conversions, total weight loss peaked at 27.4% at 2 years and was 20.9% at 5 years (Kermansaravi et al., Scientific Reports, 2022). Results depend on adherence to nutrition, activity, and follow-up.

OAGB conversion offers strong improvement in type 2 diabetes, insulin resistance, hypertension, dyslipidemia, sleep apnea, and fatty liver disease.

Long-term success requires protein-forward nutrition, resistance training, avoiding slider foods, maintaining muscle mass, and consistent metabolic follow-up. Body composition monitoring is essential.

OAGB may improve reflux in some patients but may worsen bile reflux in others. Patients with severe GERD may benefit more from RYGB conversion. Hiatal hernia repair is performed when needed.

Future revision options include limb length adjustments, pouch resizing, conversion to RYGB for bile reflux, or conversion to SADI-S or DS for metabolic failure.

Preserving lean mass is essential for long-term success. Patients are guided to prioritize protein intake, resistance training, hydration, and body composition monitoring.

Most insurers cover revisional surgery when medical necessity is documented, including inadequate weight loss, metabolic disease, or sleeve complications.

Pre-op requirements may include bloodwork, imaging, endoscopy, nutrition consultation, psychological evaluation, and medication adjustments.

After OAGB, you progress from clear liquids to full liquids, purees, soft foods, and then regular textures, with protein goals and vitamin supplementation as essential parts of every stage.

Early walking starts the day of your sleeve-to-OAGB conversion, light activity continues for two weeks, and a resistance training program is usually added at week 4–6.

Patients traveling for sleeve-to-OAGB conversion should share any history of reflux, because bile reflux is a consideration with OAGB. Budget approximately seven days in Miami. Follow-up includes virtual symptom checks and lab reviews.