Revision bariatric procedures

 

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.

The crucial learning points are:

  • Recognize that certain eating behaviours and eating habits need to change after surgery (and this is the responsibility of the patient).
  • Recognizing the importance of following dietary advice and maintaining a regular exercise program after bariatric surgery.
  • Understand that weight regain occurs with all types of bariatric operations.
  • Understand that revisional bariatric surgery is extremely complicated, potentially hazardous and doesn’t automatically equate to more weight loss after.

Please refer to the section on “Roux Y gastric bypass” for further information on this specific operation. Please refer to “Nutrition and exercise after surgery” for post operative instructions.

This blog discuss revisional bariatric procedures in the context of weight regain rather than for correction of anatomical complications from previous other surgeries.

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The benefit of bariatric/metabolic surgery

Behavioural and medical approach (without surgery) to obesity result in 5-10% weight loss in the short term but unfortunately this is not maintained over time. Bariatric surgery leads to much greater weight loss reduction (50-75% excess weight loss) and this weight loss result is more durable.

When bariatric surgery is compared to medical weight loss program without surgery, Roux Y gastric bypass and sleeve gastrectomy has been proven to have superior results not just with regards to excess weight loss and fat loss, more importantly surgery results in resolution of medical co-morbidities and reduction in premature cardiovascular mortality.

In the last decade health authorities (prominent obesity and diabetes societies from many countries) have strongly endorsed surgery for morbid obesity (BMI>40) or people with multiple medical co-morbidities and BMI greater than 35 (for the Caucasian population) because of the high remission rate of medical co-morbidities in particular type 2 diabetes mellitus and other important metabolic conditions (central obesity, hypertension, dyslipidaemia) as well as resolution for a range of clinical problems (obstructive sleep apnoea, degenerative joint diseases, etc.).

The American Medical Association (published in JAMA 2004) reported amazing results attesting the benefits of surgery, with resolution of obstructive sleep apnoea (in 87% of cases), type 2 diabetes (77%) and hypertension (62%). Since then many other studies have proven the similar benefits of bariatric surgery.

Conversely without surgery metabolic complications of morbid obesity is estimated to reduce life expectancy by at least 5-20 years.

However despite good success of the initial bariatric surgery unfortunately there is always a potential for relapse, return to old eating habits and consequently weight regain.

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Eating disorders

Before we discuss weight loss failures, it is important that we mention and ruled out any psychiatric disorder or eating disorders first. These conditions are important, need professional evaluation and deserved to be treated properly.

Eating disorder is defined as either insufficient or excessive food intake followed by compensatory behavior such as restrictive or purging. Psychiatrist diagnoses and categorizes eating disorders as anorexia nervosa, bulimia or eating disorder not otherwise specified.

Many of the bariatric patients or potential candidates for bariatric surgery does not necessary have an eating disorder but it is important to recognize there are different eating patterns. These eating patterns are helpful for predicting extent of post operative weight loss or the risk for weight re-gain. The different types of eating behaviour may also partly explain for the differences in percentage of excess weight loss amongst individuals who had the same operation.

 

 

Inappropriate eating behaviour

Researchers have described several types of inappropriate eating behaviour, which are not part of any psychiatric disorder. The common ones are listed below. Obviously recognizing the patterns of inappropriate eating behaviour will assist individual patients to make plans towards changing the “learnt” bad behaviours that has developed over the years or even maybe wrong eating behaviours adopted from early childhood.

Grazing:

Describe people who consume small amounts of food frequently throughout the day and outside of the five main meals (breakfast, mid-morning snack, lunch, afternoon snack, dinner).

Emotional eating:

Describe people who eat in response to emotional arousal states (fear, stress, anger, anxiety).

Sweet eaters:

Describe people who prefer to consume high calorie foods (soft drinks, alcohol, sweets, desserts).

After dinner grazing:

Describe people who graze after dinner.

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Post op instructions after weight loss surgery

Please refer to the section on “Nutrition and exercise after surgery”. Adherence to instructions given by the dietician is strongly advised.

Some important dietary facts

In the post-operative phase it is essential to have a food plan to maintain a lower body weight. Preferences should be given to consuming protein food and avoiding saturated fats and sugars/carbs.

Simple sugars are present in soft drinks, fruit juices, cookies and desserts but many are not aware that sugars are also added to nutrition bars, soups, salad dressings, processed foods, etc. The above should be avoided in the early post op phase because during the adaptation state the body learnt what is the new normal level of sugar that is to be consumed by the individual.

It is preferable to avoid high GI index (simple sugars) food or starch/carbs when attempting to lose weight. White flour found in white bread for example is rapidly digested and cause a rise in blood sugar. Instead patients should focus on eating proteins (such as fresh salmon/tuna sashimi or lean cuts of meat). On the other hand egg yolk, nuts and grains are very high in protein and calorie, so if consumed, the portion size should be significantly reduced.

Margarine has higher levels of trans fat, high levels of LDL cholesterol and low levels of HDL cholesterol and has been associated with non alcoholic steatohepatitis. In contrast butter has lower level of trans fat. Consumption of saturated animal fats, margarine or butter should be kept to a minimum. Lean meats and meats without skin is recommended and butter is preferred over margarine.

Similarly dieticians may also advice to avoid hydrogenated oils, canola or sunflower oil. Olive oil, avocado or salmon oil is preferred.

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The important role of a multidisciplinary team

Having excluded eating disorders, the responsibility for behaviour change or change in eating habits is very much up to individual patients, well guided and supported by the team, which may include surgeons, physicians, general practitioners, dieticians, exercise physiologist, etc.

The role of the surgeon is to ensure the patient receives all the necessary and important clinical information, to be well advised regarding the appropriateness of bariatric surgery and to perform the operation correctly, avoiding any technical errors. After surgery the change in eating behaviour needs to come from the patients.

From the outset we should mention that majority of patients will be having only one type of bariatric operation and should not rely on revisional procedures for inadequate weight loss results or failure of resolution of medical problems. Also it is important to emphasize that prevention of weight re-gain is more important than how to treat weight regain.

First and foremost we emphasize that the goal should always be loss of body fat, in particular central/visceral obesity not just focusing on total body weight. Patients should avoid lean body (muscle) mass loss. These non adipose tissue is responsible for most of the resting metabolic rate, regulation of body temperature and assist with maintained long term excess weight loss.

The role of an exercise physiologist after surgery

Thus preserving lean muscle is very important by maintaining adequate protein intake after surgery and regular physical activity. In the first 2 to 4 weeks post op, protein replacement shakes provide the daily requirement until return to solid diet and meats. Apart from providing the required daily protein requirements, protein shakes also helps to induce satiety, assist with weight loss, help to maintain muscle tone and body contour.

On discharge from hospital, the standard post op instructions are to complete the protein shakes and commence gentle activities at home, such as walking. Patients are encouraged to adhere to the instructions given by the dieticians and consider making an appointment to see an exercise physiologist after surgery.

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The disadvantages of bariatric/metabolic surgery

Weight loss and re-gain after successful initial surgery

It is commonly quoted that laparoscopic sleeve gastrectomy can achieve between 50-60% excess weight loss in 12 months. Bariatric surgery candidates often do set realistic goals for weight loss and improvements in medical co-morbidities although differences do exist between patient and physicians/surgeons expectations.

After all types of bariatric operations (be it sleeve gastrectomy, gastric bypass or other malabsorption procedures), there are potential for weight regain in the long term (after 2 to 5 years). Weight regain of 8-9% of initial weight (or 4-8% of initial BMI) has been reported.

The common reasons for weight re-gain after bariatric surgery includes:

  • Dilatation of the remnant gastric sleeve/pouch or gastro-gastric fistula (after a gastric sleeve or bypass respectively) resulting in loss of satiety and increased food intake (volume eaters).
  • Poor adherence to post operative instructions regarding diet choices and lack of regular exercise or physical activity.
  • Increased caloric intake of high GI index foods (sweets, carbohydrates), fats or alcohol.
  • Return to poor eating habits such as binge eating, emotional eating and grazing.
  • Side effects of certain medications that promote fluid retention, increase appetite and weight gain.

Weight re-gain is not uncommon and in fact is expected after any bariatric operations. 50% of patients have weight re-gain after 5 years but if the amount is not significant or excessive, the initial surgical procedure is still worthwhile.

On the other hand weight loss treatment failure has been described as those who did not achieve more than 50% excess weight loss in the long term. Treatment failure rate has been reported to be as high as 7-20% after 8 years.

Again it should be emphasized that the aim of bariatric/metabolic surgery should be an overall improvement in quality of life, resolution of medical co-morbidities, reductions of visceral obesity and metabolic complications, rather than just focusing on kilograms or weight loss alone.

Return of medical co-morbidities after successful initial surgery

Those in the higher BMI group and those who have more associated metabolic problems (especially diabetes, hypertension and cardiovascular disease) are more likely to have weight re-gain in the long term.

Excess body fat (especially central or visceral fat) is associated with metabolic syndrome, which is associated with a risk of adverse cardio-vascular event. With weight re-gain it is expected that some patient will also develop a relapse of their medical co-morbidities. The return to body visceral adipocytes once again has the potential to result in insulin resistance, secretion inflammatory cytokines and various toxic substances resulting in the vicious cycle of morbid obesity and metabolic syndrome. Hence further medical treatment or even revisional surgery may be necessary for some.

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Reasons for revisional bariatric surgical procedures

There has been a significant increase in the number of primary bariatric operations since it was recognized that surgery is the most effective treatment for morbid obesity in terms of weight loss and resolution of medical co-morbidities.

Like Type 2 diabetes mellitus, which is recognized as a progressive disease, obesity is also regarded as a chronic disease that also has the potential for long term therapeutic failure and a need for further intervention.

The two facts (mentioned above) naturally will lead to a parallel increase in revisional bariatric procedures for inadequate weight loss from the primary operation or weight regain with time.

The choice of revisional surgery depends a lot on the specific indication for re-operations, preferences of the surgeon and the patient’s choice. Many experienced surgeons perform revision laparoscopic bariatric procedures but the operations are technically challenging, time consuming and carry a higher complication rate. Not only that, significant weight loss after revision surgery is not guaranteed and it may bring a whole new set of side effects and complications (such as reflux, malabsorption, etc.).

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Higher risk for revisional procedures

The revisional operations are often very difficult due to many factors such as intra-peritoneal adhesions, distorted anatomy (especially around the hiatus and gastric cardia), thick wall stomach that is hard to transect (due to fibrosis, oedema, previous sutures, etc.) and concerns above staple line complications (such as ischemia and leaks).

From the long list of different types of bariatric surgeries above, it is understandable that the surgeon needs to be experienced enough to understand the variety of problems that each primary procedure may bring and how to successfully convert them to a better, safer and more effective longer term alternative.

It is important to stress the fact again that for some patients, revisional procedures does not guarantee additional significant excess weight loss and may introduce a whole new set of clinical problems (such as nausea, reflux, dumping syndrome, malabsorption).

It is worth mentioning that some of the anatomical problems are not or may not be reversible, for example gastric pouch dilatation, reflux from a chronically weakened lower oesophageal sphincter pressure, oesophageal dilatation or dysmotility as a result of an inappropriately placed gastric bands.

Often not talked about is that weight loss failure may be due to associated behavioural factors such as emotional eating disorders, increased appetite or weight gain from side effects of certain prescribed medications (eg. for depression/anxiety), lack of dietary compliance or inadequate physical exercise rather than actual technical failure of the operation. Obviously these behavioural issues cannot be corrected with further surgery.

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Types of primary and revisional bariatric procedures

Listed below are examples of some of the common operations that had been performed in Australia, some were done many decades ago and are no longer carried out today.

The primary restrictive procedures include:

  • Non adjustable gastric bands
  • Laparoscopic adjustable gastric band (LAGB)
  • Vertical banded gastroplasty (VBG)
  • Horizontal gastroplasty

The primary restrictive/hormonal or malabsorptive procedures:

  • Laparoscopic sleeve gastrectomy (LSG)
  • Laparoscopic Roux Y gastric bypass (RYGBP)
  • Open bilio-pancreatic diversion +/- duodenal switch (BPD-DS)

Common revisional procedures include:

  • Removal of gastric bands
  • Re-insertion of gastric bands
  • Reversal of VBG
  • Revision surgery for RYGBP
  • Conversion VBG to RYGBP
  • Conversion LAGB to LSG/RYGBP or minigastric bypass (MGB)
  • Conversion LSG to RYGBP or DS

In Australia the revision bariatric procedures have been performed mostly for failed restrictive procedures (such as the vertical banded gastroplasty and gastric bands). The sleeve gastrectomy has been a relatively new introduction into our country and we have not required to convert a large number of sleeve gastrectomy yet. It remains to be seen whether a significant proportion of failed sleeves will need to be converted to a gastric bypass down the tract.

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Wide variety of re-operative procedures are performed

The gastric band reoperations have been the most common revisional procedures in Australia due to patient intolerance, band problems (leakage, slippage, erosions), tube or port problems (leakage, infections, incisional hernia), inadequate weight loss or weight re-gain. Although some surgeon performs replacement of gastric band, the indication ideally should only be for patients who had good success with restriction in the past without band intolerance and upon specific patient request. Conversion from band to sleeve gastrectomy or band to bypass usually has better success in terms of further excess weight loss, resolution of obstructive eating problems (food bolus obstruction, regurgitation, reflux), food tolerance and better quality of life.

Although there have been reports of removing the gastric band and converting to sleeve gastrectomy at the same time (which can be achieved with low complication rates and the weight loss results achieved is comparable to primary sleeve gastrectomy), most surgeons would be reluctant to recommend this because of the unpredictable intra-operative findings adding to the complexity of the revisional surgery and the much dreaded complication of staple line leaks.

The less common reversal procedure is for gastric outlet obstruction as a result of stricture after a VBG. This can simply be achieved by laparoscopic reversal of the VBG (a stapled gastro-gastrostomy above the stricture) for instant relief of constant vomiting. But a conversion to laparoscopic Roux Y gastric bypass (which is done for gastro-gastric fistula or weight re-gain) is a completely different proposal, a much more complex operation.

The sleeve gastrectomy is a very versatile operation, which has been described as a stand alone primary procedure, a bridge to gastric bypass or duodenal switch. Recently gastric band conversion to LSG has also been performed (more so for patient intolerance of the band rather than for weight loss failure or regain). As with many therapeutic decisions made in medicine, converting from a band to a sleeve gastrectomy, Roux Y or minigastric bypass is often based on the patient’s choice.

Conversion to gastric bypass (RYGBP) is the procedure of choice for many surgeons for inadequate weight loss after a failed restrictive procedure and for patients with specific complications of the proximal gastric pouch (such as gastric band erosions or slippage, VBG stricture or gastro-gastric fistula). RYGBP facilitate further weight loss and at the same time improve gastric emptying, minimise reflux and with gravity assisted emptying, it may also help those with oesophageal dysmotility.

The primary RYGBP has been reported to have a 10-20% risk of failure of adequate weight loss or weight re-gain. The options for revisions include a banded bypass or introduce a more malabsortive procedure, such as the long limb or distal gastric bypass. However the complications and nutritional consequences may be undesirable (especially dumping, multivitamin and mineral deficiencies) and further weight loss result is not guaranteed.

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Summary

It is inevitable that there will be revisional surgeries in the future.

For now most of the revisional procedures has been for removal of gastric bands because of patient intolerance or specific complications of the band.

But in the future with weight regain and return of medical co-morbidities, potentially there will be more patients seeking revisional bariatric procedures.

The choice of revision surgery, the implications of a malabsorptive procedure (such as the Roux Y gastric bypass) and the associated higher complication rate for revisional procedures, all need to be carefully considered before the patient embark on another operation.

Going back to the opening remarks of this blog, it is more important to recognize the factors which predict weight loss failure, weight regain or recidivism and to make deliberate efforts towards ensuring proper behavioural change, compliance to dietary advice and maintaining regular physical activity/exercise rather than rely on revisional surgery for failures in the long term.

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