Obesity is one of the greatest challenges facing society at this time. It is now the most common health problem in our community. It affects approximately one in five Australian adults. Obesity can be best defined as a disease in which fat is accumulated to the extent where health is impaired. Obesity can be measured and defined in a number of ways. The most commonly used is using the body mass index (BMI). The BMI is a measure that combines the weight and height according to the formula BMI, equals weight in kilograms divided by height in meters squared. There are a number of other measures of obesity that can be used in particular situations but BMI is the most commonly used. The side effects of obesity are far ranging.

As BMI increases, one’s life expectancy decreases. This becomes particularly apparent as the BMI increases over 35 and particularly once the BMI is greater than 40, the risk of death is nearly three times that of people with normal weight. This is due in part to the obesity itself and also to the medical diseases that are caused or exacerbated by excess weight. The list of these diseases is long and includes:

  • Diabetes
  • Hypertension
  • Dyslipidaemia
  • Ischaemic heart disease
  • Asthma and other lung disease
  • Obstructive sleep apnoea
  • Gallstones
  • Non alcoholic steato-hepatitis
  • Urinary incontinence
  • Gastro-oesophageal reflux
  • Arthritis
  • Back pain
  • Infertility
  • Polycystic ovary syndrome
  • Obstructive complications
  • DVT and PE
  • Depression
  • Cancer
  • Venous ulceration

In addition to obesity there are a number of other physical social and economic costs.

Many of the illnesses related to obesity can in fact be reversed or their severity greatly reduced with effective weight loss, even as little as 10% of excess body weight but ideally two thirds of excess body weight can be associated with substantial health benefits and as a result, weight loss is one of the most powerful therapies available in medicine today. There are clearly two mainstreams of effective weight loss. The first is dieting and supportive medical care and this has been shown to be able to produce effective weight loss but requires continuous commitment and the cessation of any diet, weight is typically regained. The alternative for many patients who have found that their weight rebounds after medical treatment is to undergo an obesity or bariatric operation. Obesity operations fall into two main groups:

  • Restrictive procedures – includes laparoscopic sleeve gastrectomy or laparoscopic adjustable gastric banding.
  • Restrictive procedures in combination with a bypass procedure of some kind.

All of these procedures result in very effective weight loss. All bariatric procedures have been shown to be associated with an improvement in patients’ type II diabetes, with one study suggesting 84% of patients had a complete or partial benefit from the procedure. Similarly hypertension, abnormal blood cholesterol levels, non alcoholic steato-hepatitis, obstructive sleep apnoea, infertility, polycystic ovary syndrome and pregnancy have all been shown to be easier to manage following laparoscopic bariatric surgery. Gastro-oesophageal reflux disease (heartburn and regurgitation, also known as GORD) in the context of obesity can respond well to weight loss. While there are very good data in support of laparoscopic fundoplication for symptomatic GORD, for patients also seeking sustained weight loss, a bariatric procedure may address both GORD and weight loss. The choice of procedure will be the result of consultation between patient and doctor. 

It is important that expectations of why one is trying to lose weight and how much weight loss needs to be achieved, as well as what options need to be avoided need to be established early before working out the most appropriate option for any patient. Clearly it is important that any person begins with the simplest and safest options, which clearly involves dieting, consultation with your general practitioner and a dietician. Unfortunately most of the non-surgical options are not yet effective enough for treating obesity in those with BMI’s of greater than 35. The surgical options are all effective in terms of weight loss but vary in their risk and reversibility. You should discuss these options with your own Doctor.

Gastric reduction surgery

Normally the stomach has a large capacity, so you can eat a large amount of food before you feel full.  When food leaves the stomach it is digested and absorbed in the small intestine, and any undigested food particles and fibre pass through the bowel until excreted.

There are three main types of gastric reduction operations currently performed in Australia.

  • Gastric bypass
  • Sleeve gastrectomy
  • Gastric banding

All of these reduction operations involve making a small stomach pouch (or new stomach) and a new small outlet from the stomach pouch.

This reduces the capacity of your “new stomach” to about the size of a small egg, with a volume of about 20ml. The new small outlet from the stomach pouch has small diameter, so that it empties more slowly. This means that a small amount of food will make you feel full for a longer period of time. This is the key to their success in helping people to reduce their food intake and lose weight.

After gastric reduction surgery, food passes into the stomach pouch, filling it quickly with a small amount of food, before slowly passing through the new small outlet either directly into the small intestine (gastric bypass operation) or into the lower stomach (sleeve gastrectomy , gastric banding and vertical banded gastroplasty).

Sleeve gastrectomy

Sleeve gastrectomy is a purely restrictive operation. It involves resection (permanent removal) of 80 - 90% of the stomach, converting it to a narrow tube with a smaller volume.
It was initially designed as part of a staged management strategy that gave the option of performing key hole surgery for people whose weight would normally preclude it. The sleeve gastrectomy was done as the first operation and was later converted to a gastric bypass, which may then be performed as key hole procedure in a lighter, fitter patient,
Preliminary data suggests that early weight loss is encouraging, but whether it will be sustained beyond the first few years as a standalone procedure is unknown at this stage.
Typically the procedure would be performed laparoscopically with 5 small incisions 5-15mm in size. Hospital stay varies, but is usually 3-5 days. On discharge, you will be on a thick fluid diet for an additional 2 weeks, then a diet of semi-solid pureed food for one week, before upgrading to a normal diet for the fourth week onwards. Meal portion sizes will be similar to those for laparoscopic bypass and laparoscopic adjustable gastric banding and further guidance will be provided during consultation with our dietician.
The major risks associated with sleeve gastrectomy include, but are not limited to:

  • Staple line leak from the stomach. This occurs in <2% of patients, but is a potentially devastating complication. If a leak occurs, the management varies according to the size and site of the problem. It may require further surgery, which may include repair of the site and drainage, or conversion to roux-en-Y gastric bypass (see below). Sleeve gastrectomy leaks may require endoscopic procedures and the placement of stents in the oesophagus and stomach to control to hole. Leak will result in a prolonged hospital stay that may be weeks or even months.
  • Bleeding. Bleeding from the staple line on the stomach occurs uncommonly, but may require further surgery to control it.
  • In the longer term, GORD may develop into a significant problem following sleeve gastrectomy for 5-25% of patients. This is the result, in part, of back pressure into the oesophagus from the narrow stomach tube. If GORD symptoms are not controlled by anti-acid medication, then conversion to roux-en-Y gastric bypass is likely to be required.

Gastric bypass

The gastric bypass operation involves creating a small stomach pouch in the upper part of the stomach by using two or four rows of staples. This separates the pouch completely from the remainder of the stomach (but the stomach is NOT removed). Part of the small intestine is then joined to the new stomach pouch and a new small opening is made between them. This means that food passes directly from the new stomach pouch into the small intestine, “bypassing “the reminder of the old stomach and the first part of the small intestine.
Typically the procedure would be performed laparoscopically with 5 small incisions 5-15mm in size. Hospital stay varies, but is usually 3-5 days. On discharge, you will be on a thick fluid diet for an additional 2 weeks, then a diet of semi-solid pureed food for one week, before upgrading to a normal diet for the fourth week onwards. Meal portion sizes will be similar to those for laparoscopic bypass and laparoscopic adjustable gastric banding and further guidance will be provided during consultation with our dietician.
The major risks associated with laparoscopic gastric bypass include, but are not limited to:

  • Staple line leak. This occurs in <2% of patients, but is a potentially devastating complication. If a leak occurs, the management varies according to the size and site of the problem. It may require further surgery, which may include repair of the site and drainage. As with sleeve gastrectomy, leak will result in a prolonged hospital stay that may be weeks or even months.
  • Bleeding. Bleeding from the staple line on the stomach occurs uncommonly, but may require further surgery to control it.
  • In the longer term, internal hernias may form and the bowel can twist. This causes a blockage of the gut and can affect approximately 15% of patients at any time, even years after the surgery. Once diagnosed, surgery to relieve the obstruction may be required. It is important to let your doctor know that you have had bypass surgery.

Lap Band

It is the adjustability of the band that is a crucial component of its success. We ideally want to get you to a phase where you are getting very good satiety from small meals and not hungry. We referred to this as the “green zone”. We perform your first band adjustment four to five weeks after your band is placed. There after we perform further fine tuning adjustments every three to four weeks. It can take months in some situations and only one or two adjustments in others before you reach the green zone. Everyone is an individual and don’t be alarmed at the time it may take you personally. If we have too little fluid in the band you will recognise this by being able to eat relatively easily and hunger. If there is too much fluid in the band you will have difficulty eating and may even experience vomiting. We will discuss how you are feeling on each visit. Band adjustment is done simply with a needle through the skin and into the port placed in you abdominal wall. This has very little pain associated with it and only takes a few minutes in the majority of situations. We will be looking for weight loss of half to one kilogram per week. Do not expect to be losing weight faster than this and in fact it is potentially dangerous to do so. It is very important to be patient. Remember that more than 80% of people have a good outcome after a lap band and if it is taking you some time to lose weight that is ok. We won’t find what you maximum weight loss is until you reach a point one to two years after your band has been placed.
Laparscopic adjustable gastric banding, while the simples surgical procedure to perform, also has the highest need for re-operations. Over the long term, up to 5% PER YEAR of patients with need surgery to correct slipped lap band, gastric pouch dilation or even erosion of the band through the gastric wall. The surgical options for lap band problems include revision of the lap band (effective weight loss is maintained for 50-60% of patients), removal of the lap band, or removal and conversion (usually in a separate procedure) to a gastric bypass or sleeve gastrectomy. These options are individual decisions and should be discussed with your surgeon.

Am I suitable?
To be considered for gastric reduction surgery you need to be suffering from the disease of obesity. This means that your BMI needs to be greater than 35 and have an obesity related illness (such as diabetes) or your BMI needs to be 40 or greater without any co-existing medical problems. You must also show that you have made significant effort to reduce your weight over a prolonged period of time. This may have included a supervised diet or other commercial weight loss groups. It is important that you can lose weight on diets as gastric reduction surgery does require attention to the diet for it to work. You will also need to be able to clearly understand the risks associated with undergoing the surgery. You will also need to commit to being able to follow the rules regarding eating and drinking, exercise and activity as well as come back for permanent follow up at least every 6 months.

Outcomes
A recent review of clinical studies of various weight loss treatments (Colquitt et al Cochrane Database Syst Rev. 2014) found that surgery results in greater improvement in weight loss outcomes and weight associated comorbidities compared with non-surgical interventions, regardless of the type of procedures used. When compared with each other, certain procedures resulted in greater weight loss and improvements in comorbidities than others. Outcomes were similar between RYGB and sleeve gastrectomy, and both of these procedures had better outcomes than adjustable gastric banding. Isolated sleeve gastrectomy led to better weight-loss outcomes than adjustable gastric banding after three years follow-up. This was based on one trial only.  Most trials followed participants for only one or two years, therefore the long-term effects of surgery remain unclear.

Optimising your outcome after your weight loss surgery
Exercise and increased activity is a fundamental component of a successful outcome following your weight loss surgery. You should endeavour to exercise for at least 30 minutes per day but aim for an hour per day. Energetic walking is a very common form of exercise but should you require any guidance in this area we would be happy for you to work with an exercise physiologist to help you achieve your best possible outcome. We generally advise that you avoid extremely strenuous lifting for four weeks after your surgery. After this period there is no restriction on the type of exercise that you perform. If you can afford it, you may find a personal trainer and invaluable assistant for your exercise program

Overall to achieve the best outcome after your surgery it will be important that you eat three (or even less) small meals per day. This means for breakfast something the size of one weetbix, for lunch half a sandwich or the equivalent and at dinner half a cup of vegetables with a small piece of meat 1cm in thickness and no larger than the size of the palm of your hand. It is important not to eat anything between meals. You must eat slowly and take 20-30 minutes to eat your main meals. It is important to stop when you are no longer hungry. You should focus on nutritious foods and avoid calorie containing liquids. Fundamentally, you must always keep in contact with our clinic and if you feel that things aren’t going well you should feel free to contact us anytime.

Pregnancy following bariatric surgery
You will need to wait 18 – 24 months after bariatric surgery before trying to conceive so that the foetus is not affected by the rapid maternal weight loss. After bariatric surgery your chances of conceiving are increased so adequate contraception needs to be put in place for the 18 – 24 month period after your surgery. The risk of oral contraceptive failure is also increased post bariatric surgery, so non-oral contraceptives should be considered.

Vitamin deficiencies are very common post-bariatric surgery. Protein, Iron, Folate, Calcium, and vitamins B12 and D are the most common nutrient deficiencies after gastric bypass surgery. Nutrient deficiencies can also occur after restrictive surgical procedures, such as adjustable gastric banding, because of decreased food intake or food intolerances. It may be extra difficult to get the nutrients you need during pregnancy because of nausea, a common post-surgery complication that morning sickness can exacerbate. You should be tested for any deficiencies at the beginning of your pregnancy and a complete blood count and measurement of Iron, Ferritin, Calcium, and vitamin D levels every trimester should be considered. Make sure you inform your obstetrician of your bariatric surgery. 

Because of the risk of delayed post-operative complications, gastrointestinal problems that are common in pregnancy (nausea, vomiting, abdominal pain) require thorough evaluation in women who have undergone bariatric surgery.
Your bariatric surgery should not affect the management of your labour and delivery. Although rates of caesarean delivery are higher in women who have had bariatric surgery, it is not an indication for caesarean delivery.

Risks of surgery
Gastric reduction operations are major surgery. If you are above your healthy weight range, you are at a higher risk of suffering a complication than someone who is within their healthy weight range.

There is a small but very real risk of death from complications.

Problems that can occur during and early post-surgery include:

  • Heart attack
  • Death
  • Gastric perforation requiring conversion from laparoscopic to open operation or further surgery following the operation
  • Leak from the anastomosis or staple line
  • Haemorrhage (excessive bleeding)
  • Infection and breakdown of the wounds
  • Delayed healing of the wounds
  • Chest infection (pneumonia)
  • Blood clots in the legs and lungs

Although measures are taken to reduce the risks of these problems, some complication does occur in about 10 – 20% of all people who have this type of surgery. However, complications that prolong the time in hospital are uncommon.

Possible complications following gastric reduction surgery

Flabby skin
Loose, flabby skin can occur when a large amount of weight is lost or if weight loss happens quickly. This is because being overweight stretches the skin. This is more common on the arms, breasts, abdomen and thighs. Following the advice for regular daily exercise as you lose weight can help to reduce the amount of flabby skin and improve body tone. If flabby skin does occur surgery to remove the excess skin folds can be considered when your weight has stabilised.

Vitamin and mineral deficiencies
Vitamin and mineral deficiencies can occur after gastric reduction surgery, particularly after gastric bypass. While you are losing weight you should take Iron, folic acid and multivitamin and mineral supplements. Vitamin B12 levels will also need to be checked after gastric bypass with regular blood tests, Iron should always be taken with vitamin C to improve absorption.

Hernia in the incision
Sometimes a hernia can occur along the incision. A hernia is the bulging out of the internal organs through a weakness. Hernias are repaired by surgery.

Hair loss
This is a common side effect of rapid weight loss. About half the people who undergo gastric reduction surgery experience some hair loss in the first year after surgery. However you will not go bald and hair loss is only temporary.

Change in bowel habit
There can be a tendency for bowels to be either looser or harder than before the operation. Constipation can be avoided by taking Benefibre mixed in water daily.

Stomach ulcer
Ulceration around the outlet from the stomach pouch is rare. It if occurs it may be able to be treated with medications that reduce the amount of stomach acid. If it is due to erosion of the band or mesh into the stomach then it may require surgery to remove the band of mesh.

Alcohol absorption
Alcohol absorption may be altered, especially after gastric bypass. Therefore the legal limit of 0.05 may be reached much earlier than it was before surgery.

Bloating and abdominal discomfort
It is wise to avoid fizzy / carbonated drinks as belching may not be normal and can lead to bloating and abdominal discomfort.