There is sufficient evidence to demonstrate that One Anastomosis Gastric Bypass/Mini Gastric Bypass (OAGB-MGB) can be considered a safe and effective option as a revisional bariatric surgery procedures, according to an international team of researchers who carried out a systematic review of more than 1,000 patients. The literature review was published in the paper, ‘One Anastomosis/Mini Gastric Bypass (OAGB-MGB) as revisional bariatric surgery after failed primary adjustable gastric band (LAGB) and sleeve gastrectomy (SG): A systematic review of 1075 patients’, in the International Journal of Surgery.
“This is the first published systematic review on this topic. In the last two decades LAGB and SG were increasingly being performed. However, studies have shown that the need for revision/conversion after LAGB and SG can be as high as 25% and 10% respectively,” said led by Mr Chetan D Parmar (Consultant Surgeon, Whittington Hospital and Honorary Associate Professor, University College London, UK). “We will be seeing an increasing number of revisional bariatric cases. OAGB-MGB is safe and technically easy operation which has only one anastomosis and the limb length can be easily tailored according to the BMI of the patient. We think it should be in the armamentarium of all bariatric surgeons offering revisional surgery and could be preferred over other revisional operations.”
The authors noted that OAGB-MGB is reported to be the third common bariatric procedure performed after SG and RYGB, moreover, revisional bariatric procedures are increasing worldwide as primary bariatric procedures fail or present with complications in the long-term. For example, the United Kingdom (UK) national bariatric registry reports revisional procedures increased from 6.1% in 2012 to 11.4% in 2015. Restrictive procedures such as laparoscopic adjustable gastric banding (LAGB) and SG are getting revised with the rate of revisional/ conversion surgery as high as 26.0% for LAGB, 9.8% for SG and 4.9% for RYGB. Therefore, the study authors, performed a systematic review to evaluate the role of OAGB-MGB as a revisional/secondary procedure in patients who needed revisional surgery.
In total, 17 studies were included in the review (1,075 patients), the most common primary operation in the studies included was LAGB (n=569 patients, 52.9%), SG (n=397 patients, 36.9%). Vertical banded gastroplasty (n=105 patients, 9.7%) and laparoscopic gastric plication (n=5 patients, 0.5%). The most common reason for the revisional procedures included poor response (81%), gastric band failure (35.9%), gastroesophageal reflux (13.9%), intolerance (12.8%), staple line disruption (16.55%), pouch dilatation (17.9%) and stomal stenosis (10.3%).
The authors report that the mean BMI during primary procedure was 47.05kg/m2 compared to the mean BMI at revision to OAGB-MGB of 41.6kg/m2. After OAGB-MGB the mean percentage excess weight loss (%EWL) was 50.8% at six months, 65.2% at one year, 68.5% at 24 months and 71.6% at five years. They also found that revisional OAGB-MGB led to ‘satisfactory’ resolution of comorbidities in most patients: T2DM in 80.5%, hypertension in 63.7% and GORD in 79.4%.
In addition, they reported for OAGB-MGB revision procedures:
- The readmission rate was 4.73%
- The mortality rate was 0.3%
- The leak rate was 1.54%
- Anemia rate of 1.9% were reported
- The marginal ulcer rate was 2.44%
- Post-operative GORD rate was found in mean of 3.29% patients.
The review showed that the limb length varied from 150-250cm in this cohort for revisional surgery. Whilst the authors acknowledge that a longer limb length could be used when considering OAGB-MGB for revisional surgery (particularly if the indication for revisional surgery is poor weight loss due to primary bariatric surgery), they cautioned that in such instances the whole length of small bowel length should be measured as >200cm BPL can increase chance of malnutrition. Therefore, they recommended that based on published literature, a limb length of 200cm should give satisfactory results in revisional surgery cases.
“This review of 1,075 patients suggests that OAGB-MGB can be a safe and effective choice as revisional surgery for poor weight loss or weight regain and/or comorbidity recurrence after failed primary bariatric procedure…” the paper concludes. “Randomised studies and large prospective studies with long term follow up are needed to validate these findings and compare effectiveness of OAGB-MGB with SG or RYGB as a revisional procedure.”