Laparoscopic Reversal of Gastric Bypass: A Retrospective Review

Gastric bypass surgeries are commonly performed as metabolic bariatric surgeries [1]. The anatomic changes of gastric bypass allow the food bolus to reach the jejunum directly through the gastrojejunostomy, and the excluded stomach and duodenum have no contact with the ingested food bolus. These anatomic changes lead to alterations in glucose kinetics, absorption of minerals and micronutrients [2], and postprandial levels of gastrointestinal (GI) and pancreatic hormones [3]. With dietary adjustments and supplementation of standard micronutrients and minerals, most patients experience benefits from these changes after undergoing gastric bypass. Although primary metabolic surgery typically has low instances of early postoperative complications such as bleeding or leaks from anastomosis/staple lines, there may be long-term issues that may develop. After gastric bypass surgery, these complications may encompass what is known as “dumping” syndrome, reactive hyperinsulinemia leading to hypoglycemia [4], significant weight loss or weight regain [5], marginal ulcer formation [6], and malabsorption of vitamins or minerals that can cause anemia or ongoing abdominal pain, which can complicate effective symptomatic management [7]. Indications for reversal are primarily in cases that are unresponsive to conservative, multidisciplinary Management. For Malnutrition, the patient cannot sustain his basic nutritional requirements through oral intake, as evidenced by massive weight loss and persistent hypoalbuminemia. There is no clear definition of what massive weight loss is, but generally, when BMI is less than 18 kg/m² or the patient is dissatisfied with their weight loss, it is considered an indication for reversal. For marginal ulcers, when all medical regimens, such as proton pump inhibitors, fail, including failure of endoscopic management, surgical intervention may be necessary. For dumping syndrome, when all dietary modifications and medical treatments, such as acarbose, diazoxide, and octreotide, fail to prevent hypoglycemic attacks, further evaluation and treatment options should be considered [8]. Surgical interventions—classified as revisional, conversional, or reversal procedures aimed at restoring the original pre-bariatric anatomy—may become necessary [9].

Reversal of the gastric bypass to normal anatomy is recommended for patients experiencing rare, severe chronic complications. In this study, we report our extensive, single-center experience with the laparoscopic reversal of gastric bypass procedures over a 5-year period. The paucity of patients in prior studies has resulted in limited knowledge regarding the indications and complications.

This study aims to provide a deeper understanding of the most common indications, perioperative management strategies, and clinical outcomes in patients who undergo gastric bypass reversal at a specialized bariatric center.

A retrospective review was conducted involving patients who underwent gastric bypass reversal at the General and Laparoscopic Surgery Department of a tertiary care university-affiliated hospital between April 2020 and April 2025. It included patients aged between 18 and 70 who underwent reversal of gastric bypass procedures, namely Roux-en-Y gastric bypass and one-anastomosis gastric bypass. We excluded patients who had undergone conversion to another bariatric procedure, such as sleeve gastrectomy, or who had a history of previous intestinal surgery.

In the current study, the primary indications for reversal were malnutrition (hypoalbuminemia, 33%) and excessive weight loss (29%), followed by chronic abdominal pain, chronic anemia, and other complications (10% each). These findings are consistent with prior studies, such as the study by Himpens et al. [1], which identified malnutrition and intractable symptoms as key reasons for reversal [1]. Similarly, a Danish study (2024) reported malnutrition and excessive weight loss as leading causes, though their cohort had a higher proportion of patients with chronic abdominal pain (26.3%) [5]. This discrepancy may reflect differences in patient selection or preoperative management strategies.

The mean operative time in our study was 65 min, which is comparable to other series reporting laparoscopic reversal times ranging from 60 to 120 min. Svensson et al. [4] reported a mean operative time of 70–110 min. Additionally, in the Danish multicenter study published in 2024, the mean operative time was 60 to 90 min [4, 5].

Regarding early postoperative complications (e.g., bleeding or leakage), there was one early postoperative complication in the form of leakage (10%). This case underwent reversal of RYGB due to chronic abdominal pain. On postoperative day 5, we noticed vital instability and repeated vomiting. After resuscitation, we requested a CT scan, which revealed leakage from the anastomotic line between the distal biliopancreatic limb and the proximal Roux limb, which was taken down and re-anastomosed. The patient experienced a smooth postoperative recovery and was discharged uneventfully 6 days later.

Our results are concordant with several published series, which report leak rates ranging from 5 to 10% following the reversal of bariatric surgery. For example, Snyder et al. conducted a multicenter review of 92 patients who underwent reversal of Roux-en-Y gastric bypass and reported a postoperative leak rate of 8.6% [10]. Similarly, Moon et al., using data from the MBSAQIP database, found a leak rate of 6.2% in revisional bariatric surgeries overall, highlighting the increased risk associated with these complex procedures [11].

Additionally, Pearl Ma et al. reported a leak rate of 10% in their study, describing a ninefold increase in leakage rate and nearly doubling the hospital stay following revisional procedures [12].

The current study reported one mortality due to liver cell failure. This patient has undergone OAGB 3 years prior to the presentation and suffered from severe malnutrition and liver cell failure. The patient received supportive treatment in the form of IV fluids, albumin, vitamins (thiamin, B12), electrolyte correction, and TPN. The patient was discharged after 1 week for a home regimen of TPN. After the MDT consultation, the decision was Made to proceed with a reversal. The patient was admitted to the ICU, and supportive treatment was administered to improve his general condition. Reversal was done after 5 days, but unfortunately, the liver cell failure led to generalized anasarca, and the patient died eventually.

This is comparable to the 15–20% morbidity rates reported in larger series (e.g., [10, 11]). Also, Pearl Ma et al. reported a mortality rate of 6% in a 3-year postoperative period [12].

Unlike Himpens et al., who reported no mortalities, our 10% mortality may reflect the inclusion of higher-risk patients with end-organ damage [1].

These findings address the technical demands of reversal surgery and suggest that lower complication rates need procedural standardization, surgeon experience, and multidisciplinary perioperative management.

The main indication for reversal in this pilot study was malnutrition (33%). In most cases, malnutrition could be managed conservatively by oral feeding, tube feeding, and/or TPN administration. However, when malnutrition becomes severe and resistant to standard treatment, the options for available care remain limited. Nutritional counseling serves as the primary intervention; however, in certain situations, surgical intervention—such as shortening the biliopancreatic limb and extending the common channel—may be considered. When dietary modifications alone cannot manage malnutrition and temporary nutritional support, such as total parenteral nutrition (TPN) or gastrostomy tube feeding, has been exhausted, a permanent surgical solution should be considered.

In our study, the mean albumin level preoperatively was 2.95, reflecting a moderate to severe protein depletion, while in other studies like Ahuja et al. [2], it has a reported value of 2.7 and a reported value of 2.9 in a study published by Sanchez-Pernaute et al. [2, 3].

The mean increase in albumin levels 6 months postoperatively was 0.6, which is comparable to other studies that range between 0.5 and 0.8 [1, 5]. These results are consistent with prior research highlighting the role of anatomical restoration in normalizing nutrient absorption.

Twenty-nine percent of our patients underwent reversal for excessive weight loss and inability to gain weight with nutritional counseling and supplementation.

A significant proportion of our patients (62.5%) experienced weight regain at 6 months post-reversal, with a statistically significant increase in BMI (p = 0.013). This aligns with findings from other studies, such as those by Ahuja et al. [2], where weight regain was reported in 50–70% of patients after reversal [2]. Additionally, our study demonstrated a significant improvement in albumin levels (p = 0.019), highlighting the effectiveness of reversal in addressing malnutrition.

A refractory marginal ulcer was an indication in one patient in our study. In most cases, a marginal ulcer can be managed conservatively with a stepwise approach, starting with lifestyle modification and oral proton pump inhibitor (PPI) administration, followed by intravenous PPI administration and then IV infusion. If failed or complicated, trials of endoscopic treatment can be tried. When marginal ulcers are refractory to all the previously mentioned measures, surgical intervention should be considered [12].

The patient’s symptoms were severe abdominal pain and bleeding, and the patient underwent several endoscopic trials but failed. His symptoms improved dramatically after reversal of RYGB, as evident by the questionnaire from.

This is aligned with a study published in 2025 stating that Marginal ulcers represented 14% of the main indications for gastric bypass reversals [13].

On the contrary, refractory marginal ulcer was reported to be the main indication for reversal (52%). Marginal ulcer is a frequent (> 10%) complication of RYGB, most commonly caused by Helicobacter pylori infection, tobacco use, or non-steroidal anti-inflammatory drugs [12]. All of these factors can be prevented or treated medically. That is why the selection of patients and the MDT approach in decision-making can be a factor in limiting the percentage of patients with marginal ulcers undergoing reversal procedures.

In our cohort, 75% of patients reported improved quality of life post-reversal, which is comparable to rates reported in other studies (e.g., 70–80% in [4]). However, 12.5% of our patients experienced worsening reflux, a known risk of reversal surgery. This highlights the importance of thorough preoperative counseling [4].

Our study provides detailed data on the laparoscopic reversal of both Roux-en-Y gastric bypass (RYGB) and one-anastomosis gastric bypass (OAGB). In contrast, most studies have focused solely on RYGB (e.g., [14]).

The inclusion of OAGB reversal addresses a gap highlighted in Robert et al.’s [15] systematic review, which reports a 21.4% higher risk of malnutrition in OAGB patients compared to RYGB patients [15]. The use of a standardized questionnaire to assess symptom severity and quality of life pre- and postoperatively enhances the objectivity of our findings. The statistically significant improvements in BMI and albumin levels provide robust evidence for the metabolic benefits of reversal in selected patients.

The preliminary data from the current pilot study suggest the potential efficacy of laparoscopic reversal of gastric bypass for patients with severe, treatment-resistant complications; however, it should be reserved as a final resort when all conservative approaches have failed.

Laparoscopic reversal of gastric bypass is a complex surgery requiring a specialized bariatric center and an experienced surgical team in revisional bariatric surgery. This kind of surgery should be a last resort for severe, intractable, chronic symptoms. Patient education about relatively high morbidity and the possibility of dissatisfaction is crucial.