The sleeve gastrectomy is recommended for most patients because it is safer and have less risk or complications

• The reflux and weight regain are the most common concerns

The gastric bypass have a lot more follow up issues, side effects, risk and complications both in the short and long term

• There common issues are listed below and there may be a lot more not mentioned in this section
• Some of these complications are extremely serious with a higher risk for hospital re-admission and small risk of mortality
• Some patients may need the gastric bypass reversed

Please do your research carefully before contemplating metabolic and bariatric surgery

Abdominal pain and gastric ulcers after gastric bypass Marginal ulcer and internal hernia are frequent causes of abdominal pain after RYGBP Marginal ulcers have been reported between 0.6 to 25% after RYGBP *Most surgeons find that incidence of marginal ulcers to be between 16-19% Marginal ulcers can also be found in asymptomatic patients as well   Gastroscopy for diagnosis and classification of the ulcer is performed Marginal ulceration is commonly treated with proton pump inhibitors, NSAIDs and smoking cessation with 56% success rate   PPI medication 40 – 80mg daily with Sucralfate 1g tds for at least 6 to 8 weeks   Revision surgery has been reported to be performed in 9-44% of patients with marginal ulcers, with failure of medical treatment but no clear guidelines to the timing of the revision surgery   High risk for marginal ulcer includes male gender, cigarette smoking/vaping, NSAIDs, alcohol, foreign body staple material and excessive weight loss after surgery

Hypoglycaemia after gastric bypass Laparoscopic RYGBP was first reported in 1994 buy American surgeons Laparoscopic RYGBP has been performed for over 30 years but the true incidence of hypoglycaemia is unknown, maybe the risk is increased 3.7 times ?   One study reported 18.7% risk for hypoglycaemia after RYGBP (compared to 5% weight loss controls who did not have surgery), with a re-admission to hospital rate of 21.3% and mortality rate of 0.71% *Hypoglycaemia may lead to dementia, macrovascular complications, falls/fractures and cardiovascular death particularly in the older population   Hypoglycaemia is a potentially serious complication after OAGB and RYGBP, especially in patients without T2DM   The reason may include changes in glucose metabolism, improved insulin sensitivity, increase secretion of GLP-1 (at 1 to 2 years post op), improvement in pancreatic B cell sensitivity (with massive weight loss after 1 year) or other yet undiscovered factors

Other post op gastric bypass issues   Some post op gastric bypass symptoms such as pain, nausea, vomiting or diarrhoea/dumping may persist with over 1/3 of patients reporting these long term upper GI symptoms and reduced quality of life   Some of the symptoms may be related to the remnant excluded stomach but often the causes are multi factorial   Many causes of these long term issues after a gastric bypass could not be found and resection of the gastric remnant is not recommended

Reversal Roux Y gastric bypass   Some patients develop serious side effects after RYGBP, which include dumping, severe hypoglycaemia, diarrhoea, malabsorption and abdominal pain *Most of the patients can be managed with dietary changes and medical management *A small percentage of patients undergo reversal of the RYGBP   Patients are often given enteral feeds to the remnant stomach for 2 to 4 weeks before reversal to determine if the symptoms are relieved before reversal *Remission of hypoglycaemic symptoms predict success of the reversal   The results of the reversal are not guaranteed *75% patients reported symptom improvement *Half of the weight is regained after the reversal with the risk of returning medical co-morbidities *The reversal helps to relieve dumping, hypoglycaemia and malabsorption but not the chronic abdominal pain or neuropathy *The reversal surgery may have more side effects and complications, some patients reported that their symptoms deteriorated after the reversal **Problems include reflux, vomiting and pain from pyloric spasm or anastomotic stricture   The symptoms of malabsorption almost completely resolved The symptoms of dumping and hypoglycaemia disappeared in 50% of the patients *For the rest the severity of the dumping symptoms was reduced For symptoms of chronic abdominal pain, 90% of patients still reported pain after the reversal For neurological symptoms, there are no improvements

Bile reflux after one anastomosis gastric bypass (OAGB)   The OAGB has rapidly gaining popularity in the last 10 years due to the technical ease, low early morbidity rate, medium term effectiveness of weight loss maintenance, improvement in obesity related medical problems (hypertension, Type 2 diabetes, obstructive sleep apnoea, dyslipidaemia) and fewer complications compare to the two anastomosis gastric bypass *There have been reports of 81.8% EWL at 5 years (range 69-93%) and 62.3% at 8 years *One systematic review reported 78.2% EWL (at 24 months) and 76.6% (at 60 months) *Suboptimal weight loss <20% TWL occurs in 22% *Weight regain occurs between 7.2 to 33.4% of patients, increases with time   Bile reflux may be inevitable after some gastric surgeries, for example distal gastrectomy, vagotomy, pyloroplasty, bariatric surgery and cholecystectomy (which is sometimes performed at the same time as the gastric bypass) Bile reflux is also common in obese and diabetic patients without previous gastric surgery   Cholecystectomy performed at the same time as the RYGBP or OAGB may increase the risk for bile reflux back into the gastric remnant   After OAGB bile reflux can occur into the proximal gastric pouch as well as the gastric remnant, which may be harmful in the long term *The rate of reflux symptoms after OAGB has been reported to be between 2-57% *Most are alkaline/bile reflux and do not respond to antacids *Reflux may still occur despite technical alterations with a long narrow pouch, side to side gastro-jejunostomy and anti reflux sutures   Often the bile is not the sole cause of oesophagitis, there may be an element of mixed acid and alkaline/bile reflux *One study using HIDA scans reported bile reflux into the stomach pouch in 53% and oesophagus in 21% of patients *Reflux symptoms may be experienced by the patients even with a negative HIDS scan, perhaps there is a component of acid reflux   Cholecystectomy also can increase bile reflux in patients even without bariatric surgery After cholecystectomy the increase bile in the duodenum may lead to duodenal reflux into the remnant stomach *However there is lack of evidence to suggest the bile reflux is carcinogenic   Late complications of OAGB include bile reflux (in 2% and this may be under reported), nutritional deficiencies and liver failures

Inadequate weight loss and weight regain after one anastomosis gastric bypass   The OAGB has been reported to have best weight loss outcome (and resolution of T2DM) compared to the RYGBP and sleeve gastrectomy, with better sustained weight loss at 5 years follow up   After OAGB the % EWL (excess weight loss) has been reported to range between 69 to 93% One systematic review reported %EWL 78.2% (at 2 years) and 76.6% (at 5 years)   However with all types of bariatric surgery there will be a group of patients who experiences suboptimal weight loss (<20% TWL) (total body weight loss) One study after OAGB reported 22.3% (5 years), 24.2% (6 years) and 22.7% (at 84 months) still have BMI over 35   There is also recurrent weight gain after OAGB as with other types of bariatric surgery One study reported recurrent weight gain (>30% of the initial weight loss) to be 7.2% (3 years), 15.5% (at 4 years), 21.6% (at 5 years), 29.7% (6 years) and 33.4% (84 months)

Gastric pouch resizing after gastric bypass   Metabolic and bariatric surgery with the gastric bypass is one of the most effective and sustainable treatment for weight loss and resolution of metabolic complications and obesity related medical co-morbidities *Surgery is a step up approach to diet and exercise, pharmacological and endoscopic therapy   However recurrent weight gain has been reported in up to 40% (range 3.9 to 40%) of patients after RYGBP with risk for recurrence of the medical co-morbidities   Weight regain is multi factorial (complex, multi layered) which may include a combination of technical factors, dietary non adherence and hormonal imbalances *Obesity is regarded as a chronic and progressive disease, there is no single aetiology for weight regain   One of the technical factor may include enlarged gastric pouch or retained posterior gastric pouch +/- a hiatus hernia, dilatation of the gastro-jejunostomy and/or delayed gastric pouch emptying with reduced satiety   For dilated gastric pouch some surgeons had performed the gastric pouch resizing, to amplify the restriction, reduce the volume and restore efficient gastric pouch emptying *Small amount of weight loss result or weight stabilization may be achieved, around 10% over 5 years follow up     Gastric pouch resizing alone has the least complications and avoids the potential complications of a major bypass revision surgery   Studies with gastric pouch resizing combined with banding/minimizer rings, shortening of common channel, etc) demonstrated no significant differences in terms of additional weight loss *Signs of dysphagia and malnutrition may be seen with these methods   Other secondary procedures such as long limb bypass, bilio-pancreatic diversion and duodenal switch has the highest long term complications and re-admission to hospital

IFSO 2024 statement   Below is a brief summary from IFSO regarding endoscopic and surgical options for weight regain   Endoscopic management for recurrent weight gain after gastric bypass   Dilated gastro-jejunostomy or enlarged gastric pouch may be identified in 71% of patients with RWG   This topic is controversial and some proposed methods to address the enlarged pouch or anastomosis include endoscopic argon plasma coagulation (APC) or trans oral outlet reduction (TORe) suturing with the Overstitch or surgically gastric pouch resizing       Surgical management for RWG after RYGBP   However studies have found that pouch revision +/- revision of the gastro-jejunostomy to be ineffective, as adding restriction to the gastric bypass doesn’t result in much weight loss   Other complex revision procedures may include lengthening the biliary limb or distalizing the gastric bypass   The distal RYGBP may have significant decrease in BMI at 1 year and 5 years *Acceptable weight loss result may be seen with the duodenal switch or SADI-S as well at 3 years *The least effective procedure were pouch reduction and revision of the gastro-jejunostomy     However there is no guarantee of a good outcome and more risk after more malabsorptive surgery *There may be some initial weight loss success but in the longer term there may be no relation between bowel length and outcome because of the bowel adaptation   *Also a total alimentary limb length of 300 to 400cm (common channel of at least 300cm) should be maintained to prevent protein energy malnutrition         Surgical management for RWG after sleeve gastrectomy   A revision sleeve gastrectomy may be attempted Or the sleeve may be converted to duodenal switch, SADI-S or OAGB *The results of sleeve converted to RYGBP for RWG without reflux may not be ideal *Sleeve conversion to OAGB have 6% more TWL than conversion to RYGBP but has significantly greater incidence for reflux, volume regurgitation and PPI medication use   Sleeve conversion to RYGBP is the better option for acid or bile reflux *The SADI-S or DS does not correct for the acid reflux *The OAGB may add to the alkaline or bile reflux (the YOMEGA trial reported up to 41% reflux) *However better results may be obtained from RYGBP if the BP limb is longer (150-200cm) than the original or traditional version of RYGBP (50-100cm) but comes at a cost of diarrhoea and nutritional deficiencies *Revision sleeve to RYGBP have a very high complication rate with reported rate up to 36%     Sleeve conversion to OAGB   A systematic review and meta analysis stated that sleeve conversion to OAGB with a BP length of 170 to 220cm is a good alternative compared to the endoscopic sleeve gastrectomy, re-sleeve, RYGBP, SADI-S and duodenal switch   Some studies reported remission/improvement in medical co-morbidities and significant reduction in BMI after conversion to OAGB after 2 years but there is a 10% increase in weight 3 to 5 years after the conversion procedure     Conversion to SADI-S or DS   These aggressive hypo or malabsorptive procedures is effective for weight loss and improvements in metabolic effects *Long term diabetes remission exceeds 90%   But these procedures are complex with high incidence of long term complications and re-operations Patient often develop steatorrhoea, severe anaemia and hypoalbuminaemia