UK report: Early results show safety and efficacy of MGB

The first early outcomes from UK from centre in the UK on mini gastric bypass (MGB), ‘Mini Gastric Bypass: first report of 125 consecutive cases from United Kingdom’, published in the journal Clinical Obesity, has reported that the results are ‘encouraging’ with acceptable weight loss, comorbidity resolution rates and complication profile. Although the study authors, from Sunderland Royal Hospital, Sunderland, UK, acknowledge that longer term follow-up data with greater patient numbers are required to confirm these outcomes, the study nevertheless “demonstrates early safety and efficacy of MGB in a carefully selected British obese population in a high-volume centre.”

The study authors note that there are several apparent advantages of the MGB compared with the RYGB, including the single anastomosis, shorter learning curve, fewer internal defects for herniation and ease of revision or reversal. However, due to concerns the procedure can cause symptomatic biliary reflux and the risk of gastric/oesophageal cancer has so far limited general acceptance of the procedure.

They subsequently designed a retrospective cohort study to report their experience with an initial cohort of 125 consecutive MGB patients starting in October 2012 (ended November 2014), with the first three procedures were performed with the help of an experienced MGB surgeon from abroad. As the majority of the patients at the study centre currently undergo a gastric bypass (either RYGB or MGB), all patients were considered to be included in the study, although the presence of Gastro-Oesophageal Reflux Disease (GORD) and/or hiatus hernia was a contraindication to MGB. However, patients with perceived technical difficulty for RYGB (super-obese, male, apple shaped body habitus), were offered MGB.

The procedure

The authors developed the following standardied technique for performing MGB: Closed pneumoperitoneum was established using optical insertion of 12mm port. This port was then used for camera insertion. Two further 12mm and one 5mm ports were used as working ports. A subxiphoid tract was created using 5mm port for insertion of Nathanson liver retractor. A long gastric pouch was created using Covidien TriStapler 45mm and 60mm Purple and Tan cartridges. Dissection was started at incisura and the first firing was carried out with stapler pointing towards the left iliac fossa.

A 36 French oro-gastric tube was used for pouch calibration in most cases (KM does not use it anymore). Omentum was not routinely divided. A loop of small bowel 200 cm from DJ flexure was then brought up to the gastric pouch in an ante colic, ante gastric fashion and anastomosed to it using Covidien Tristapler 45 mm Tan/Purple cartridge. Stapler entry site was then closed using 2/0 Vicryl in two layers. No attempt was made to close Petersen's defect and a leak test was performed using a dilute methylene blue solution. No drains were used.

From October 2012 to November 2014, 125 patients underwent MGB procedure a majority (68.8%) of these patients were female. The mean age of patients in this series was 45 (range 20–70) years, mean weight and BMI was 135.8 (range 85–244) kilograms and 48.1 (range 34.5–73.8), respectively. The mean operative time was 92.4 (range 45–150) minutes and the mean post-operative hospital stay was 2.2 (range 2–17) days (median 2.0 days). Fourteen patients had had previous bariatric intervention (13 balloon insertions, one sleeve gastrectomy).

Outcomes

The outcomes showed that there were no deaths, although there were two (3.2%) 30 day and five (4.0%) late (>30 day) complications.

The study authors noted 100% follow-up and the mean follow-up was 11.4 months. They reported mean weight loss of 45.6kg (range 16.1–112.7), percentage body weight loss of 33.2% (range 11.4–55.4), and percentage excess body weight loss of 71.8% (range 23.2–138.3). Figure 1 shows mean weight loss for the whole cohort at six, 12, 18 and 24 months with respective numbers available for follow-up at each time.

Figure 1: Weight loss after Mini Gastric Bypass. EWL, excess weight loss; TWL, total weight loss (Source: Clinical Obesity, John Wiley & Sons)

Comorbidities

At the start of the study, 33 (26.4%) patients has T2DM and all noticed improvement/resolution of their diabetes; 16 of the 33 (48.4%) patients were on Insulin preoperatively; 13 of them were able to stop their Insulin and the remaining three have seen reduction in their insulin doses. Eight patients have gone into remission. In addition, from 45 hypertensive patients, 13 (29%) have stopped anti-hypertensive medications and 22 (49%) have reduced their medications.

The procedure was also seen as a success by patients who, when asked, 96% of patients said that they would elect to have the operation again, with 82.4% of patients reporting a vast improvement in their quality of life.

“It is worth noting that RYGB still accounts for approximately 75% of the surgical procedures performed within our unit and MGB accounts for an approximate 15%,” they write. “Over the years, we also seem to be recommending MGB for the patients, who in the past were offered sleeve gastrectomy for perceived technical difficulty.”

They also comment on the link between MGB and the risk of gastric and/or oesophageal cancer, and state that they cannot find any evidence that the MGB procedure puts patients at a higher risk of cancers in the long term. Despite the lack of data, they do acknowledge that MGB will continue to be ignored by some critics who claim a lack of long term, in spite of a similar lack of long term data for gastric banding and sleeve gastrectomy.

“Other surgeons are well advised to make themselves aware of all the technical and controversial aspects of this procedure before embarking on it,” they write. “As we have seen it in our practice, even in the hands of experienced bariatric surgeons, this operation has a definite learning curve. The authors believe time is now ripe for a well-designed, multicentre, adequately powered randomised controlled trial comparing MGB with RYGB and sleeve gastrectomy.”