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Weight Loss Surgery (Bariatric Surgery)

Obesity, a disease

In 2017-18, the Australian Bureau of Statistics’ National Health Survey showed that two thirds (67.0%) of Australian adults were overweight or obese (12.5 million people), an increase from 63.4% in 2014-15. The National Health Survey also indicated that almost one quarter (24.9%) of children aged 5-17 years were overweight or obese in 2017-18 (17% overweight and 8.1% obese).

Obesity is a disease, not a choice

Obesity is recognized by leading health organizations, including the World Health Organization, as a chronic disease. Associated with decreased life expectancy and many co-morbidities, obesity requires a long-term and comprehensive management approach to help people achieve and maintain successful weight loss.

People with obesity generally make many serious attempts to lose weight but losing weight and maintaining weight loss is difficult. The “yo-yo” effect refers to the inability to sustain weight loss through dieting and exercise alone, and the body’s insistence to restore this weight loss and to gain a little extra in case another period of relative starvation occurs.

Most health care professionals believe obesity is a disease, and many view it as serious, or more serious, than many other health conditions, including high blood pressure, diabetes, and depression. Despite this general consensus, there is a strong belief held by people with obesity that weight loss is their own responsibility. Combined with their relatively low concern about impact of weight on future health, this may contribute to their not seeking medical care for their disease.

The National Institutes of Health and the World Health Organization have both adopted BMI as a criterion for defining obesity.

Read more about ‘obesity as a disease’-

In people who are moderately obese (BMI 30-35 kg/m²) life expectancy is 2 – 4 years less than with an ideal body weight. Severe obesity (40-45 kg/m²) reduces life expectancy by 8-10 years, comparable with the effects of life long smoking.

There is an increased risk of the following illnesses with obesity

  • Stroke, coronary heart disease, hypertension
  • Type 2 diabetes
  • Obstructive sleep apnoea (OSA), asthma
  • Gallbladder disease, gastro-oesophageal reflux disease
  • Cancers of the bowel, oesophagus and pancreas
  • Kidney disease, kidney cancer, urinary incontinence
  • Osteoarthritis, lower back pain, mobility disability
  • Menstrual disorders, subfertility/infertility
  • Breast cancer, endometrial cancer, ovarian cancer
  • Depression, anxiety, disordered eating

Factors contributing to Obesity

The regulation of body weight involves complicated feedback systems that result in changes in appetite, energy intake and energy expenditure.  The causes of obesity are complex.

Diet and physical activity are central to the energy balance equation, but are directly and indirectly influenced by a wide range of social, environmental, behavioural, genetic and psychological factors – the relationships between which are not yet fully understood.

Obesity could be a caused by a combination of the following:

  • the genes you inherited from your parents
  • how well your body turns food into energy
  • your eating and exercising habits
  • your surroundings
  • psychological factors

Obesity Surgery – Are You A Candidate?

Widely accepted criteria which make a person suitable for weight loss surgery include:

  • Weight greater than 45kg above the ideal body weight for sex, and height.
  • BMI > 40 by itself or >35 if there is an associated obesity illness, eg. diabetes or sleep apnoea
  • Reasonable attempts at other weight loss techniques
  • Age 18-65
  • Obesity related health problems
  • No psychiatric or drug dependency problems
  • A capacity to understand the risks and commitment associated with the surgery

Obesity – Treatment Options

Non-Surgical Treatment

Dieting, exercise, and medication have long been regarded as the conventional methods to achieve weight loss. Sometimes, these efforts are successful in the short term. However, for people who are morbidly obese, the results rarely last. For many, this can translate into what’s called the “yo-yo syndrome,” where patients continually gain and lose weight with the possibility of serious psychological and health consequences.

Recent research reveals that conventional methods of weight loss generally fail to produce permanent weight loss. Several studies have shown that patients on diets, exercise programs, or medication are able to lose approximately 10% of their body weight but tend to regain two-thirds of it within one year, and almost all of it within five years**. Another study found that less than 5% of patients in weight loss programs were able to maintain their reduced weight after five years*.

Surgical Treatment

Why perform surgery for morbid obesity?

Morbid obesity surgery is not cosmetic surgery. All doctors recognise that once a patients’ weight exceeds a certain range they are more likely to suffer from a wide range of illnesses such as diabetes, sleep apnoea, asthma, hypertension, arthritis, varicose veins and skin problems. Their chances of dying at a premature age is also greatly increased. Their employment prospects, mobility and social acceptance also suffers. Depression is much more common in the morbidly obese.

The main aim of this surgery is to bring your weight down to a safer range where most of these associated conditions are reduced in severity and many completely reversed. Along the way most people find an improvement in their mobility, body image, self-esteem and enjoyment of life.

Obesity – Surgery

Gastrointestinal surgery for obesity, also called bariatric surgery, changes the normal digestive process. The operations promote weight loss by decreasing absorption of nutrients and thereby reducing the calorie intake.

Each operation has inherent risks and varying degrees of weight loss success. Generally the operation associated with the greater risks has the higher success rates of excess weight loss.

Surgical Options

  • Laparoscopic Sleeve Gastrectomy (LSG)
  • Laparoscopic Single Anastomosis Gastric Bypass (SAGB). Also known as “mini- gastric bypass” MGB
  • Laparoscopic Roux-en-Y Gastric Bypass (RYGB)
  • Laparoscopic Adjustable Gastric Banding


  • Intra Gastric Ballooning
  • Biliopancreatic Diversion BPD
  • Sleeve Plication

Laparoscopic Sleeve Gastrectomy (LSG)

The Laparoscopic Sleeve Gastrectomy (LSG) is currently the most popular operation worldwide. Around 70% of patients undergoing weight loss surgery in Australia choose this procedure. The laparoscopic sleeve gastrectomy (LSG) is a restrictive weight loss operation. The majority of the stomach is removed and the shape of the stomach is changed from a sac to a long narrow tube (sleeve). The gastric volume is reduced dramatically to about 150mls. This is a non-reversible procedure.

The main effect of the LSG is from the reduced volume of the stomach and hence only a small amount of food results in the feeling of fullness and satiety. Using the LSG as a tool for portion control allows the committed patient to eat small meals and feel satisfied, unlike being on a simple diet. The subsequent reduction in caloric intake will result in weight loss. Good food choices as well as regular exercise are also necessary to optimise outcome.

Recent studies have shown that the top fundus part of the stomach which produces the hunger hormone Grehlin is being removed during sleeve gastrectomy. This usually resulted in loss of hunger feeling, although it does tend to lessen with time.

This procedure was initially used as a staged procedure for management of the heavier and more risky patients. It was used to reduce the initial weights of these high risk patients so that they can then have subsequent gastric bypass surgery.

Increasingly LSG has been performed as a stand alone procedure with acceptable results in the medium term (Excess weight lost of 60 – 65 %). The main surgical complications are bleeding and leakage from the cut edge of the remaining stomach (reported 1-3 %).

Laparoscopic sleeve gastrectomy is a safe and effective procedure, with good results in the short and medium term. Long-term follow-up reveals a tendency to weight regain after approximately 2 years from primary surgery, with the need for revisional surgery in a minority of cases. Up to 50% of patients will report some symptoms of reflux or heartburn at 5 years.

Single Anastomosis Gastric Bypass (SAGB) or “Mini Gastric bypass” (MGB)

A mini gastric bypass creates a long narrow tube of the stomach along its right border (the lesser curvature). The remnant stomach is anastomosed (joined) back to the small intestine, approximately 150-200 cm from the start of the intestine. The surgery works by both restricting the amount of food intake and reducing the amount of time food has to mix with digestive juices.

This is an increasingly popular operation around the world and in Australia. An attractive feature of the MGB is that it can be “reversed” relatively simply, with restoration of “normal” anatomy, in the unlikely setting of a complication or side effect. Potential complications of the MGB include bleeding, leak, and the potential to develop bile reflux, which may require conversion to the Roux-en-Y bypass. Lifelong supplementations should also be an expectation.

MGB diagram

Roux-en-Y gastric bypass (RYGB)

The Laparoscopic Roux-en-Y Gastric Bypass (LRGB) is the current “gold standard” weight control operation. It is the operation to which all other procedures are historically compared.

In this operation, the top part of the stomach is stapled off to create a small gastric pouch with a volume of about 100mls. The jejunum is divided and the cut end of the jejunum is attached to the small stomach pouch. The other small bowel end is joined back to the small bowel about a metre down from the stomach. With this re-routing, the remainder of the stomach and the top end of the small intestine (duodenum) are bypassed.

This type of bypass operation has proven to be an effective, consistent way of losing weight and keeping it off, but to achieve these results it requires lifelong changes to lifestyle and eating.

This procedure has the highest complication rate, however the weight loss is more consistent and patients can expect to lose more weight than with other procedures. The expected average weight loss is between 60 – 75% of excess weight and will still be influenced long-term by exercise and diet. Patients will need to take daily supplements for the rest of their life. The complications that arise from dividing and stapling include bleeding, leaks from joins or staple lines, and bowel obstruction. This operation also has the life long potential for an internal hernia to develop. If the small intestine becomes entrapped in the internal hernia the patient may become very unwell and will need urgent surgical treatment.

Both the mini gastric bypass and Roux-en-Y gastric bypass have an excellent effect on treating diabetes associated with obesity.

Source: NHMRC Clinical Practice Guidelines for the Management of overweight and obesity in adults, adolescents and children in Australia and the OSSANZ website.

Umbilical / ventral / incisional hernia repair

A ventral hernia is a defect in the anterior abdominal wall (the front of the abdomen). Defects/hernia generally occur at sites of congenital or acquired weakness ie at the umbilicus, the upper midline (epigastric hernia) or at the site of a previous surgical incision. Generally a hernia will not cure itself, will get larger and may, at an inconvenient time, incarcerate or trap its’ content; either fat or bowel. Generally most people have hernia repaired on an elective, planned basis. Ventral hernia can be repaired either laparoscopically (using keyholes) or via an open approach (directly, through an incision). The preferred technique depends on the size, number and contents of the defect/s, the patients’ body habitus and past medical and surgical history, all part of Dr Shaw’s thorough assessment. Most hernia repairs performed in an elective setting require a combination of non-absorbable suture material and the use of a reinforcing mesh, a non absorbable, synthetic, sterile material that gives extra strength to the repair. Specific risks of elective hernia repair include bruising, a haematoma (collection of blood in the wound), infection and recurrence of the hernia at a later stage. The laparoscopic approach also introduces potential intra-abdominal risks which can be explained in further detail at the time of your consultation.

Ventral hernia repair can be performed as a day procedure or may require an overnight stay. Recovery rates vary amongst individuals yet most people will be back at work within a week or two, or longer if heavy lifting is a requirement of work.

Colonic cancer surgery

Colon cancer is the second most common cancer in adult Australian males and females. Symptoms include per-rectal bleeding, a change in bowel habit, weight loss or symptoms of anaemia including fatigue or breathlessness. Preferably cancer can be detected at an asymptomatic stage using faecal occult blood tests (FOBT) or at screening colonoscopy. After the diagnosis is made, the disease is staged with CT and surgery considered. Most surgery for colonic cancer can be performed laparoscopically. The colon is mobilized from its’ peritoneal attachments laparoscopically and the tumour is excised with a margin of healthy tissue. A small incision is then required to remove the portion of the bowel containing the tumour. The bowel continuity is then restored using a variety of techniques. Risks inherent in surgery include bleeding, infection, damage to surrounding structures and anastomotic leak. There are also risks involved with general anesthesia. Most people will spend between four and seven days in hospital. The role of post-operative chemotherapy will be determined by the pathology report. Dr Shaw will go through the surgery in greater detail at the time of your consultation.

Laparoscopic cholecystectomy for gallstone disease

The gallbladder is the most common organ removed from the human body. Gallstones develop for a number of reasons, many of them beyond the control of the individual. When gallstones become symptomatic, surgery to remove the gallbladder is warranted. This procedure is performed laparoscopically under general anaesthesia. The goal of the surgery is to remove the gallstones and the gallbladder without damaging surrounding structures. An xray (Intra-Operative Cholangiogram, IOC) is performed during the procedure to assess for any gallstones within the common bile duct and to gain information regarding the biliary anatomy. Stones seen on the IOC may be removed laparoscopically (common bile duct exploration, CBDE). If CBDE is unsuccessful, a post-operative endoscopic procedure (ERCP) will be required to clear the bile duct. Laparoscopic surgery to remove the gallbladder is considered very safe and effective. It is still major surgery however with inherent risks and potential complications. These include bleeding, infection, bile leak and common bile duct injury. Risks associated with general anaesthesia include sore throat, pneumonia, heart attack, stroke, deep vein thrombosis/pulmonary embolus (DVT/PE) and death. An open operation through a right upper quadrant incision is needed only rarely.

Most people having a laparoscopic cholecystectomy will require an overnight stay, although a day case can be arranged. Recovery rates vary amongst individuals yet most people will be back at work within a week or two, or longer if heavy lifting is a requirement of work.

Umbilical / ventral / incisional hernia repair

Groin hernia occur at sites of congenital weakness and can be caused by general wear and tear or in situations when the intra-abdominal pressure is chronically elevated e.g. with chronic cough or straining at the time of bowel motion. Most hernia present as a lump with associated discomfort in the groin. It is important to differentiate a muscular strain or tear in the groin from a hernia. Generally a hernia is diagnosed clinically with the palpation of a lump. An ultrasound scan is often also helpful. Dr Shaw prefers the laparoscopic approach when repairing groin herniae. This procedure is performed under general anaesthesia. The groin is approached “from behind” after making an incision below the umbilicus. Insufflation of carbon dioxide helps create and maintain a working space to allow the hernia to be identified and the contents reduced. Important structures need to be preserved. The defect is then covered with a sterile, synthetic mesh which is fixed in place with glue or absorbable tacks. Specific risks of groin hernia repair include bleeding (presenting as a either a bruise or haematoma), infection (very uncommon) and recurrence of the hernia. Some people also have temporary difficulty passing urine in the immediate post-operative period and may require a catheter to be placed in the bladder for the night. This can normally be removed without trouble the following day.

Groin hernia repair can be performed as a day procedure or may require an overnight stay. Recovery rates vary amongst individuals yet most people will be back at work within a week or two, or longer if heavy lifting is a requirement of work.

Hiatus hernia repair

Gastro Oesophageal Reflux Disease (GORD)

The oesophagus carries food from the mouth to the stomach. The lower oesophageal sphincter is a ring of muscle at the bottom of the oesophagus that acts like a valve between the oesophagus and stomach. It is supported by the muscle of the diaphragm. Gastro Oesophageal reflux disease, or GORD, is a chronic disease that occurs when the lower oesophageal sphincter does not close properly and stomach contents reflux back into the oesophagus. When refluxed stomach acid touches the lining of the oesophagus, it causes a burning sensation in the chest or throat called heartburn. The fluid may even be tasted in the back of the mouth. Heartburn that occurs more than twice a week may be considered GORD, and it can eventually lead to more serious health problems. Some people have GORD without heartburn. Instead, they experience pain in the chest, hoarseness in the morning, or trouble swallowing. You may feel like you have food stuck in your throat. GORD can also cause a dry cough and bad breath. GORD can be caused by a hiatus hernia, alcohol use, being overweight, pregnancy and smoking. GORD can also occur in perfectly healthy people with normal anatomy. Certain food and drinks are also associated with reflux.

The diagnosis is usually made on the clinical history and with the use of a trial of a Proton Pump Inhibitor (PPI), a contrast swallow Xray or an upper endoscopy. Further testing with 24hr pH monitoring or oesophageal manometry may be necessary.

Conservative treatment includes life style modification e.g. losing weight, ceasing smoking. Medications are generally very effective and include antacids, H2 receptor blockers (Rani), and Proton Pump Inhibitors (PPIs) e.g. Losec, Nexium, Somac.

Surgical treatment is an option when medicine and lifestyle changes do not work. Surgery may also be a reasonable alternative to a lifetime of medications and discomfort. Surgery is generally performed laparoscopically (five keyholes), patients spend between one and three days in hospital, and are normally back at work within one to two weeks. Surgery aims to restore and reinforce the patients’ anatomy by closing any defect and wrapping the upper stomach around the lower oesophagus. This can be either a partial wrap or a 360 degree wrap (Nissen fundoplication). Satisfaction with surgical correction of reflux disease is generally high. Risks inherent in the procedure include bleeding, infection, inadvertent injury to the gut or surrounding organs and risks of general anaesthesia. Functional side effects include a reduced ability to burp or vomit, gas bloating and excess flatus. With re-do surgery, vagus nerve damage is possible and this can alter one’s gastro-intestinal habit dramatically.

Appendicectomy, perforated bowel, bowel obstruction

Dr Shaw is available for emergency surgery and is happy to take calls directly from your general practitioner. Many abdominal surgical emergencies can be performed laparoscopically (keyhole surgery). Depending on the nature of the pathology a laparotomy (opening the abdomen) may be required. Ultimately as long as surgery is performed safely and competently the patient should recover well regardless of the incision or approach used. The indication for surgery and the risks involved with surgery will be discussed in detail at the time of your presentation.