This blog provides free general information for anyone who is seeking to understand more about revisional bariatric procedures, not intended as a medical consult. Please seek proper medical advice for individual assessment and management.

Introduction For patients with a BMI >30 with Type 2 diabetes mellitus or BMI >35 Metabolic and bariatric surgery is the most effective treatment *for morbid obesity and obesity related co-morbidities *for improvement of health and quality of life *for reduction in cardio-vascular risk factors and obesity related co-morbidities *for reduction in premature cardio-vascular mortality, cancer related and all cause mortality     Quantitative vs qualitative measures: The primary end point of metabolic and bariatric surgery is to lose weight and reduce the above co-morbidities/complications *The aim is >50% excess weight loss or >20% total body weight loss *Not to have a weight regain of more than 15% in the long term *Resolution rate of high blood pressure, Type 2 diabetes mellitus, obstructive sleep apnoea are expected in approximately 70-80% of patients   The secondary end point and the other potential non measurable benefits include: *Reduce the chronic inflammation on a microscopic level *Improvement in dietary habits, increase physical activities/endurance, personal motivation and mental health *Improvement in social and employment opportunities     Risk benefit ratio   But the weight loss response of bariatric surgery varies a lot between individuals leading to suboptimal weight loss or weight regain despite initial successful primary intervention in the long term   Obesity (similar to Type 2 diabetes) is viewed as a chronic progressive disease There is potential for weight regain and relapse of the medical co-morbidities associated with obesity with time Complications will inevitably arise after any surgery, such as hiatus hernia, reflux, Barrett’s oesophagus, gallstones, internal hernia, adhesions, small bowel obstruction, excessive weight loss +/- malnutrition, etc     Revision surgery The multi-disciplinary team approach is there to support the patient but there are limitations of the surgical outcome in the long term Revision surgery is often is necessary in the future

Revision bariatric surgery will become more common in the future

Published literature reported that revisional operations have increased by 60% in the USA between 2011 to 2019.

Because bariatric surgery is so effective for weight loss and treatment of metabolic medical co-morbidities related to obesity, the number of primary bariatric operations had increased exponentially. Naturally with time, it is also expected that revisional bariatric surgeries will also increase.

Revisional surgical procedures are now reported to be 10-30% of all bariatric procedures performed worldwide. But this number will certainly be higher in the future based on our understanding of obesity, the natural weight loss curve and longer duration of follow up.

Categories of revisional bariatric surgery Revisional surgeries are generally separated into 3 types: *Corrective (re-operate to correct an anatomical problem) *Conversion (change to a different bariatric procedure) *Reversal (attempt to restore the original anatomy) With revisional bariatric procedures we need to determine the best timing for surgery, have pre-op patient optimization, select the appropriate type of procedure (as above) and ensure high standards or safety. *Preferable the complex revisional surgeries should be performed in a high volume centre. Indications for revisional bariatric surgery *Revisional surgeries should be considered for patients with post op issues or technical problems *Revisional surgery can be considered for selective patients who did not achieve the expected weight loss *Or there may be an overlap of both technical issues and weight regain. Examples include hiatus hernia, reflux, weight regain and return of medical co-morbidities requiring conversion to a different bariatric procedure Patients who do not have any technical complications but wish to be considered for revision surgery to achieve more weight loss usually falls in 4 categories: *Patients who achieved less than 50% EWL less than 2 years after the initial operation *Patients with weight increase more than 10kg after the nadir *Patients still have a BMI >40 or BMI >35 plus associated medical co-morbidities (satisfying the previous NIH and IFSO guidelines) *Patients with BMI >30 and T2DM requiring medications at 2 years follow up (American Diabetic Association guidelines)

Caveats of revisional bariatric surgery

With revisional surgeries, please note that the weight loss result is not guaranteed and there is a much higher early (30 days) complication rate with revisional procedures, especially with leaks, infection/sepsis/fistula, bleeding, anastomotic stricture, etc.

Secondly obesity or weight regain in the long term (similar to T2DM) should be viewed as a chronic disease requiring long term medical +/- surgical treatment.

• One operation alone may not be adequate and should be utilised to determine success or failure of bariatric/metabolic surgery.

Most importantly we should emphasize that success of bariatric/metabolic surgery should be described in both quantitative and qualitative terms.

• Clinicians and patients should not be solely focused on weight or BMI after bariatric surgery as an indicator for success or primary responder.
• Favourable outcomes include resolution of OSA, successful childbirth, reduction of pain/disabilities, improvements in social and functional quality of life as well as many other key indicators despite the patient not achieving >50% EWL after 2 years.

This is a good time to re-iterate that the goals of bariatric and metabolic surgery are many, the major indications of surgery include:

• To provide a safe and effective long term weight management coupled with behaviour and lifestyle changes
• To achieve remission or prevent progression of medical/metabolic co-morbidities and complications associated with morbid obesity (especially with T2DM, HPT, OSA, etc), to reduce cardio-vascular risk factors and major adverse cardio-vascular events (MACE)
• Reduce premature cardio-vascular mortality, cancer related mortality and all cause mortality from morbid obesity
• To achieve improvement in the social and functional quality of life
• For women in their reproductive age group, weight loss may help to increase successful pregnancy rates, there may be less complications during pregnancy and labour
• To reduce the chronic inflammation and to achieve long term reduction in the levels of pro inflammatory cytokines from the central/visceral adipose tissues
• There are other improvements after bariatric surgery which are rarely mentioned by clinicians, these include improve insulin sensitivity, increase in GLP-1 levels and incretin response, favourable gut microbiome and bile salt metabolism

Hence the intended outcomes of bariatric surgery are not just weight loss alone

• More emphasis should be placed on multi disciplinary and early (1 to 2 years) post op efforts to achieve and maintain weight loss, making positive lifestyle changes to eating habits and behaviour.
• Similarly weight regain after 5 or 10 years or longer should not be considered a failure if some of these circumstances can be predicted (eg. post op IVF treatment, multiple pregnancies, Depo-Provera, being commenced on steroids or anti-depressant medications, etc)

Non surgical treatments should be recommended to most patients first before revisional bariatric surgery due to the higher post op complication risks.

• Patients with super obesity and advanced or non reversible medical co-morbidities do not benefit as much from more drastic bariatric procedures.
• Patients with advanced age (post menopausal), certain medical conditions (hypothyroidism, reduced metabolism rate), being on medications with weight gain side effects or those with physical limitations will not benefit as much from drastic revisional bariatric procedures.

Common indications for revisional bariatric surgery

Laparoscopic gastric band was commonly performed 10 to 20 years ago. There is a high revision surgery rate because of long term complications, mainly:

• Proximal gastric pouch dilatation (40-50%)
• Inadequate weight loss or weight regain (10-18%)

Laparoscopic sleeve gastrectomy is currently the most popular primary bariatric surgical procedure worldwide and naturally with the passage of time, it is perceived that there will be more patients coming back for revision similarly for weight regain, hiatus hernia/reflux or other issues.

From a weight loss point of view, patients who had a sleeve gastrectomy initially instead of a gastric bypass, are more likely to require conversion to a different bariatric procedure in the long term (see below).

Some revision surgeries/procedures are planned or anticipated, examples include

• Super obesity or high risk patients who are planned to receive a gastric bypass as a second stage procedure
• Young female patients who wish to have children in the near future may avoid the gastric bypass until they have finished their family
• Patients who drive long distance or operates heavy machineries, who can’t risk having hypoglycaemia or diarrhoea/dumping syndrome may elect to have a sleeve gastrectomy and have the gastric bypass as a salvage procedure
• Patients in rural or remote areas without easy access to medical care may opt to have a primary restrictive procedure instead of a gastric bypass
• Some patients are expected to have regular screening gastroscopies for reflux, hiatus hernia and biopsies to check for Barrett’s oesophagus.

Some revision surgeries are for complications of previous bariatric procedures, examples include:

Post sleeve gastrectomy

• Hiatus hernia, acid or alkaline/bile reflux
• Inadequate weight loss or weight regain

Post one anastomosis gastric bypass (estimated 5% patients develop complications, 1% require re-operation) for:

• Alkaline/bile reflux
• Refractory gastric ulcers or strictures
• Inadequate weight loss or weight regain
• Excessive weight loss, dumping and/or protein/energy malnutrition

Post Roux Y gastric bypass

• Refractory gastric ulcers or strictures
• Internal hernia, small bowel obstruction
• Inadequate weight loss or weight regain
• Excessive weight loss, dumping and/or protein/energy malnutrition
• Unexplained abdominal pain/adhesions

Please note the long term complications may occur years after the primary bariatric procedure, especially with weight regain, hiatus hernia, reflux (after a sleeve gastrectomy) or internal hernia and malnutrition (after Roux Y gastric bypass).

Other surgeries may be the result of success weight loss, for example cholecystectomy (for gallstones and complications) or various plastic/reconstructive surgeries.

• The incidence of gallstones post bariatric surgery has been reported to be between 30-53%, symptomatic presentation with biliary colic in 7-25% and cholecystectomy rate of 6 to 14.7%
• But routine cholecystectomy for those without gallstones or symptoms during bariatric surgery or the use of Ursodeoxycholic acid are not routinely recommended at this stage

In summary it can be said that almost all patients should expect further gastroscopy and/or surgeries down the track after the initial bariatric procedure.

Hiatus hernia and reflux   Hiatus hernias are mostly sliding (Type 1) hiatus hernia (in about 85-90% of cases) The others are para-oesophageal hiatus hernia (type 2, 3 or 4) (in 10-15% of cases)   With obesity (BMI over 30), the intra abdominal pressure is a 2 to 3 times higher and thus there is a 4 fold increase in the risk of developing a hiatus hernia   Pre-operative rates of Barrett’s oesophagus has been reported to be very low, 1% in one study.   It is estimated that 61% of patients with obesity suffers from reflux. Some operations such as the gastric band, sleeve and perhaps the one anastomosis gastric bypass (OAGB) may worsen the pre-existing reflux or result in new onset reflux. *Most surgeons do not recommend the OAGB for patients with severe acid/volume reflux. Some studies showed that despite weight loss there was no significant reduction in reflux rate after OAGB *But revisional OAGB did show a significantly reduced of reflux post operatively after a failed restriction procedure *The new onset reflux rate after OAGB has been reported to be about 6%. Some report the conversion rate from OAGB to RYGBP is 2% for reflux, which is not very high     During primary bariatric metabolic surgery, a concurrent hiatus hernia repair can be performed at the same time when the hiatal or crural defect is found intra-operatively. *The database reported a hiatus hernia repair rate of 21% in sleeve gastrectomy and 10.8% in Roux Y gastric bypass patients. *Some bariatric registry reported that 23 to 31% of patients develop reflux after a sleeve gastrectomy. Also on CT scan there was a detection rate of 37% proximal gastric pouch migration rates after 10 months, thus it makes sense to repair the hiatus hernia at the same time. *Concurrent hiatus hernia repair is clinically effective, good GOR related quality of life with good efficacy and safety for both sleeve and gastric bypass patients.     In one study, it was demonstrated that Roux Y gastric bypass is very effective for erosive oesophagitis and resulted in 35% regression rate for Barrett’s oesophagus.

Revision surgery after sleeve gastrectomy   Systematic reviews (in 2017) reported mean excess weight loss (% EWL) was 58% (at 5 years), resolution rate for T2DM (78%) and resolution rate for HPT (68%) after a sleeve gasterctomy.   Meta-analysis (in 2018 with minimum 7 years follow up) reported weight regain 28% and overall revision rate was 20%. Another study reported weight regain with a range of 23 to 49% after 7 years.   More recent meta-analysis for sleeve gastrectomy (with 10 years plus follow up) demonstrate >20% total body weight loss (% TWL) with satisfactory remission rates for T2DM and HPT.   One study reported that post sleeve hiatus hernia developed in 42% of cases (range between 31 to 74% with 5 years follow up) even after very successful weight loss.   Post op reflux and oesophagitis has been reported to be between 19 to 41% at 5 years but Barrett’s oesophagus remains uncommon (range between 0 to 19% at 5 years).   After a sleeve gastrectomy it is estimated that 30% (23-49% within 10 years) will develop new onset reflux. 20% of these patients usually present for revision surgery within 10 years of the initial sleeve operation. *For those with pre-existing reflux before the sleeve, these symptoms may increase in up to 19% of patients.   Revision surgery is usually for reflux and weight regain, the most common being sleeve to Roux Y gastric bypass in about 19% of patients in one study. Various reports: *Overall the conversion rate is estimated to be around 6 to 22%, which increases with the duration of follow up. Most revision surgery occurs after 5 years.   *The rates of weight regain after a sleeve gastrectomy has been reported to range from 5.7% (at 2 years) up to 75.6% (at 6 years).   *2 studies reported new onset of GOR reported around 23% (at 6 years) and 26.7% (at 5 years) *1 study reported 16% and another study reported 33% of patients need long term PPI medications for GOR at 5 years follow up   Conversion from sleeve to RYGBP provides remission of reflux symptoms in 94%, reduction/cessation of PPI medication use and some small additional weight loss but these results were not reported in patients who previously had a gastric band. After conversion to bypass, there is often an improvement in the eating ability (less restriction than the sleeve), with the potential for insufficient weight loss (30% at 1 year) and maybe weight regain in a very small proportion of patients.

Revision surgery after one anastomosis gastric bypass   The new onset acid/volume reflux rate after OAGB has been reported to be about 6%. Bile reflux has been reported to be between 0.6 to 10%.   Some report the conversion rate from OAGB to RYGBP is 2% for reflux.   One systematic review and meta analysis reported marginal ulcer rate of 2.6% after OAGB, usually occurring after 12 months. 90% are managed conservatively with medication, PPI medications for about 6-12 months and sucralfate for about 2 months can be prescribed.   Reversal of OAGB is usually related to micronutrient deficiencies and malnutrition.

Revision surgery after Roux Y gastric bypass   The addition of a second anastomosis in the Roux Y reconstruction obviously increases operating time and the potential complications, which ranges from anastomotic leak, bleeding, stricture, adhesions, internal hernia, small bowel obstruction, bilio-pancreatic limb obstruction, etc.   The worst case scenario is ischaemic gut from strangulation due to adhesions or an internal hernia. Hence the Roux Y bypass is potentially a lot more dangerous than the sleeve or one anastomosis gastric bypass.   With routine closure of both defects at the jejunal anastomosis and Petersen’s site, the mesenteric defects, internal hernia rate (2 vs 6%) and re-operation rate has reduced.   However recurrent internal hernia rates have been reported to be up to 14-19% despite adequate repair during the initial RYGBP operation.   One systematic review reported 31% presentation to the emergency department 3 years after a RYGBP The re-admission to hospital rate was around 24% and mostly with abdominal pain for investigation.   *After bariatric surgery abdominal pain has been reported between 30 to 54% of patients. Common causes include hiatus hernia, reflux oesophagitis, bile gastritis, gastric/marginal ulcers, gall stones, internal hernia, small bowel obstruction, adhesions, etc. *Rare causes include anterior cutaneous nerve entrapment syndrome, incisional hernia, irritable bowel syndrome and constipation. *However over 1/3 of post op abdominal pain remains unexplained with no diagnosis or no technical issues found despite multiple investigations.     For patients with inadequate weight loss result or weight regain, revisional surgery after a RYGBP is much more complicated. The risk and long term side effects of surgery also increases significantly.   On the other side of the coin, reversal of RYGBP has to be considered for some patients. *Indications include food intolerance, excessive weight loss, malnutrition, short gut syndrome, dumping or post prandial hypoglycaemia symptoms, non healing gastric ulcers and chronic pain.

In summary:

Revisional bariatric procedures is more commonly performed nowadays for various reasons to achieve the optimal outcome, in terms of long term weight loss maintenance, resolution of medical co-morbidities and improvements in health related quality of life as well as to correct any issues from previous operations (such as hiatus hernia or reflux).

However revision bariatric procedures are much more complex, have much higher risks and complications and there is no guarantee success for achieving the desired weight loss outcome or achieve resolution of reflux or chronic pain.

Hence patients should be very well informed because they be recommended to have revisional bariatric or metabolic surgical procedures.