Causes of obesity
Besides genetic and hormonal influences, obesity occurs from excessive intake of calories - more than what is required for the body. Your body converts calories into energy for the body to use and the excess calories are converted into fatty substances, triggering obesity.
The most common causes of obesity include:
- Sedentary and physically inactive lifestyle
- Unhealthy diet and eating habits
- Lack of proper sleep
- Disease conditions such as hypothyroidism and depression
- Medications such as steroids, antidepressants, antiseizure and diabetic medications.
Complications of obesity
Obesity is associated with many serious physiological, psychological and social consequences, as listed below.
Physiological consequences of obesity are:
- Type 2 Diabetes
- High blood pressure
- Heart disease
- Gallbladder disease
- Cancer (breast, uterine and colon cancer)
- Digestive disorders (gastroesophageal reflux disease or GERD)
- Breathing problems (asthma)
- Problems with fertility and pregnancy
- Urinary incontinence
- Joint problems (arthritis)
- Shorter life expectancy
Psychological and social consequences of obesity are:
- Negative self-image
- Social discrimination and isolation
Other consequences include:
- Difficulty in performing normal tasks, as movement becomes more difficult
- Feeling tired more quickly
- Experiencing shortness of breath
- Difficulty in using public transport seats and driving cars
- Difficulty in maintaining personal hygiene
Diet vs Weight Loss Procedure
Lifestyle modifications that help to reduce body weight include dietary changes, physical activity, and behavioural changes. Dietary changes include eating healthy food rich in nutrients while avoiding high-calorie, highly processed junk foods. 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.
Weight-loss surgery, is considered only in patients with extreme obesity. It is usually considered as the best treatment option for patients who have failed to respond to non-surgical weight loss procedures like diet, medication and exercises. Weight loss surgery promotes weight loss by decreasing the amount of food your stomach can hold and limiting absorption of nutrients. The main aim of this surgery is to bring your weight down to a safer range where most of the associated conditions such as diabetes, sleep apnoea, asthma, hypertension and arthritis 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.
The Place Of Surgery In The Management Of Intractable Morbid Obesity
Morbid obesity is a serious and underestimated medical condition. It is defined as a condition in which the patient is 80% or 45kg above ideal body weight. It can cause many medical illnesses (co-morbidities). The incidence of obesity is increasing rapidly in the Australian population with up to 20% of people considered to be seriously over weight and 6% morbidly obese. Surgery is one of the only effective ways of treating this problem. The cost of treating obesity related medical illnesses in Australia is in the order of 5 billion dollars per year. Morbid obesity causes a significant reduction in the quality of life for those afflicted by it. A basal metabolic index (ratio of body weight to body surface area in square metres) of 40 or over indicates morbid obesity. A BMI of greater than 35 associated with obesity related medical illnesses is considered to indicate a serious weight problem and is the minimum level at which surgery is considered an option. Patients suffering from morbid obesity statistically lose between 15 and 20 years of their life span. This is because obesity can cause many medical problems including:
- Heart disease
- Sleep apnoea
- Osteoarthritis of weight bearing joints
- Hiatus hernia and gastro-oesophageal reflux
- Gall stones
- An increased incidence of carcinoma of the breast and prostate
The sufferer's quality of life can be poor. Low self-esteem and depression are common. Where the patient has suffered from morbid obesity for more than 5 years despite all attempts to control it by conservative means and, where they are strongly motivated to lose weight, then surgery is an option.
Patients electing to undertake a surgical solution to their problem must be aware that surgery for morbid obesity is not always successful. The surgery can fail due to technical factors such as breakdown of a staple line, erosion of a gastric band or development of an unexpected complication.
A major cause of problems or failure after surgery is the inability of the patient to comply with the instructions given to them at the time of surgery. For example, continuing to eat high calorie, semi liquid foods like ice cream and chocolate after gastric banding or stapling or not taking vitamin and mineral supplements after biliopancreatic diversion can lead to failure or complications.
For these reasons patients should select surgery if they feel it is the only way that they can control their weight problem. They must accept that despite their surgeons best efforts, in a minority of cases the surgery may not be a success and that complications are possible. Surgery on the other hand, is the most successful treatment that we have for patients suffering from the debilitating illness of morbid obesity as conservative weight reduction programs have only limited success rates.
Selection And Referral Of Patients For Surgery
- Patients should be in the vicinity of 80% or 45kgs above ideal body weight (BMI 40 or above) or have a BMI of more than 35 and have medical or psychological conditions that would benefit from weight reduction.
- They must have been overweight for at least 5 years.
- They must have tried and failed to achieve sustained weight loss by conservative means.
- They must be strongly motivated to lose weight and be prepared to make the necessary sacrifices to achieve such an end.
- They must be fit to undergo surgery and be informed of the effects and complications.
- They must be prepared to attend for continuing supervision as a lifelong commitment.
- Should be older than 15 years of age and Less than 70.
A Brief History Of The Development Of Obesity Surgery
The attempts to surgically control obesity began in the 1960s. Since then many different techniques have been used with variable success rates. All have used one or both of the methods mentioned above. There was a high failure and complication rate in the early years, partly because of technical failure, but often because of poor patient compliance and loss of motivation. The uncertainty of the success rate and the incidence of serious complications in early cases has led to a poor acceptance of surgery as a legitimate method of weight control by the medical community. However, techniques are improving and bariatric surgeons are becoming more experienced, so that results have improved markedly over the last decade. Surgery is often the only option for the seriously obese patient who, for various reasons, has failed to lose weight on diet and exercise programs.
Small Bowel Bypass
Surgery for obesity began in the 1960s with the introduction of small bowel bypass. This produced a mal-absorptive state and massive weight loss by reducing the functional length of the small bowel from the normal 7.5m to just over 1m. Unfortunately, although weight loss was excellent, follow up revealed a number of serious complications including septicaemia, liver failure, calcium loss causing bone softening, renal stones and intractable diarrhoea. For this reason the procedure fell from favour and the focus turned to the restrictive procedures.
Gastric bypass was developed by Professor Edward Mason in Iowa, USA in 1966. He had noted the weight loss that occurred after partial stomach removal for cancer or ulcer and attempted to use the principal of reducing the stomach volume to induce weight loss.
The stomach was stapled across so as to reduce its volume to 10% of normal. The small pouch so produced was attached to the upper small bowel with a 1cm. opening (stoma) between the two, a procedure known as gastric bypass. The weight losses achieved were encouraging and many centres still perform this procedure regarding it as the gold standard as far as weight reduction procedures are concerned. It is a technically difficult procedure with some risk of leakage and abscess formation at the anastomoses (joins) between the small bowel and stomach and between the loops of intestine. It is now possible to be performed laparoscopically in suitable cases. In the long term there is a failure rate for gastric bypass as a result of dilatation of the stoma or break down of the staple line. These problems result in an increase in the speed at which the pouch empties and so lead to loss of restriction and increased food intake with resultant weight gain.
Gastric Stapling Procedures
Dr Edward Mason suggested the creation of a small upper stomach pouch by placing a stapled partition across the stomach with an opening in it. This was designed to allow food to drain slowly into the lower stomach pouch producing fullness and the inability to more than a small amount of food. Operations of this type are commonly referred to as gastric stapling procedures. Food would pass through the narrow opening in small amounts and then on through the normal digestive pathway so minimizing the mal-absorption of nutrients such as iron and B12. X-ray or endoscopy could still be used to inspect the lower stomach via the stoma.
The earliest of these procedures were simple linear staple lines in which a 1cm gap was left. Many of these procedures failed because of widening of the opening between the pouches (stomal dilatation) or staple line break down. These problems allowed the patient to return to normal eating volumes and caused weight regain. The high failure rate of these early procedures has been largely responsible for the poor reputation of bariatric surgery. Many modifications have been introduced to overcome these problems. The most successful of these techniques available today is probably the vertical banded gastroplasty of Mason. This procedure seeks to overcome pouch dilatation by constructing the 15cc pouch vertically along the thick walled lesser curvature of the stomach, placing four lines of staples and strengthening the stoma by wrapping it in a nylon mesh collar to prevent dilatation. The procedure is still rather complex and requires the use of both a linear and a circular stapler.
In the Mason procedure a rigid tube 1cm in diameter is passed into the stomach. A circular staple gun is fired against the edge of the tube cutting a hole that fixes the front and back walls of the stomach together. A four line staple gun is then passed through this opening and fired parallel to the tube to produce a pouch. The opening is then wrapped in a mesh collar to stop the opening dilating and the pouch emptying too rapidly. Failure occurs due to breakdown of the staple line and dilatation of the pouch. The mesh can erode into the stomach allowing the stoma to dilate or enlarge.
Figure 1 – Vertical Banded Gastroplasty
There is some risk of leakage postoperatively at the site of the junction of the two staple lines and there are still long term failures due to staple line break down, pouch dilatation and erosion of the mesh into the gastric lumen resulting in stomal dilatation. The other major cause of long-term failure is failure of patient compliance and the patient adopting a diet high in foodstuffs such as chocolate and ice cream. These liquefy in the pouch passing rapidly through the stoma without producing satiation and so result in a high intake of kilojoules and weight regain. Continued ingestion of these semi-liquid sweet foods is one of the major causes of failure in all gastric reduction surgery.
Most of these procedures with the exception of gastric bypass have been abandoned
The Present Situation
The surgeon has only two proven methods available to him to induce weight loss:
- By restricting gastric capacity and so reducing the amount of food that a patient can ingest, the so-called gastric restrictive procedures.
- By changing the intestinal tract so as to prevent the food eaten from being digested and absorbed, the so-called mal-absorptive procedures.
The most common procedures used at present are
- Laparoscopic gastric banding
- Laparoscopic Gastric Bypas
- Sleeve Gastrectomy
- Biliopancreatic diversion
These are different approaches to the problem and I shall attempt to explain the advantages and disadvantages of each. I have included on my website information about the most common surgical procedures for the information of patients. This is for patients information only as I now only perform gastric banding surgery In the end, the patient must consider which approach they feel will be most acceptable to them. For example, if considering gastric banding, can they tolerate small measured meals, can they avoid sweets or can they adopt the slow eating and careful chewing that is necessary to make the procedure work? What will be their attitude if they develop leakage after a sleeve gastrectomy or bypass? Are they prepared to accept an irreversible operation?
My preferred option is Gastric Banding because of its safety, adjustability and reversibility. I have no deaths in my series of 1400 cases and only 4 cases in which there have been significant complications. More complex procedures such as bypass or sleeve gastrectomy are impossible or difficult to reverse and carry a much higher risk of death or leakage. Leakage can be a very serious problem and can keep a patient in hospital for months due to infection. For these reasons I have abandoned these procedures.
I strongly advise all patients considering all these types of procedure to talk to other patients about their experiences with the surgery and their satisfaction with the procedure in general.
Laparoscopic Adjustable Silicone Gastric Banding
In an effort to simplify the procedure of gastric reduction, Molina in Houston and Kolle in Oslo, in 1980 introduced the concept of gastric banding. The band wrapped around the upper part of the stomach (the fundus) and produced a small pouch of between 30 and 15 cc without the use of staples or sectioning of the stomach. The procedure is fully reversible. The initial bands of Dacron arterial graft were fixed in circumference. In 1986, Kusmak in New Jersey and Halberg in Sweden, introduced bands that could be adjusted via a balloon on their inner surfaces. The American version is referred to as the Lap Band or LAGB and the Swedish version as the Swedish adjustable gastroplasty band or SAGB. The balloon on the inner surface of these bands allows the diameter of the stoma to be changed so as to alter the rate at which the pouch empties so altering the feeling of fullness or satiation after eating. This adjustability allows fine tuning of the procedure postoperatively. Adjustment is achieved by injecting or aspirating saline into an injection port sited on the abdominal muscle. These devices have now been modified so as to allow them to be placed, since 1994, laparoscopically with benefits to the patient in terms of reduction of postoperative discomfort, increased speed of recovery and reduced scarring. They are the only adjustable form of partitioning currently available.
Patients who are addicted to sweet foods and drinks, who have a severe reflux problem and who are clinically depressed, are often unsuitable for gastric banding procedures.
Figure 2 Adjustable Silicone Gastric Banding
Laparoscopic gastric banding is my preferred method of gastric partitioning. I have a preference for the Allergan AP Lap Band System. The procedure is conducted under a general anaesthetic. Five small incisions are made in the abdominal wall and the abdomen inflated with CO2 gas. The band is passed around the upper stomach 2-3cm from the junction of the gullet and the stomach so as to produce a 12ml pouch. The band is connected to a device called an access port into which fluid may be injected to tighten the band. The procedure takes up to two hours and the patient must remain in hospital overnight after surgery. The procedure is simple, reversible and adjustable but to be successful, the patient must comply with certain eating disciplines if the procedure is to produce the desired weight loss.
- Adhere to a diet of easily masticated foodstuffs such as cereal, vegetables and white meats.
- They must measure their food volumes and eat no more than an saucer sized helping per sitting.
- They must chew every mouthful of food thoroughly and eat slowly allowing time for each mouthful to pass through the band before taking another.
- They must avoid high kilojoule semi liquid foods such as ice cream and chocolate.
- They must avoid eating when upset or rushed.
- They must take multivitamins and occasionally iron to supplement their diet.
- They should avoid eating and drinking at the same time.
- They should have six monthly blood counts to check haemoglobin, iron, B12 and folic acid levels.
- Regular exercises is mandatory. A half hour a day is advise.
Patients must be aware that complications can occur both at the time of surgery and later. Detailed information on laparoscopic gastric banding and its potential problems and complications, is available on my website.
Briefly the following problems can occur
- At surgery tearing of the stomach and bleeding from the spleen are the chief concerns. Fortunately the incidence of these problems is low in my experience of 1400 cases. I have had three gastric perforations in my series which caused infection and required band removal, repair and drainage of the infection. Conversion to open surgery to control damage and complete the procedure might be necessary
- Open operation may also be required if there are technical difficulties such as a grossly enlarged and fat-infiltrated liver, that prevents access to the site where the band is positioned or because of the presence of widespread adhesions
- Postoperatively there is a risk of slippage of the band down the stomach or of stretching of the pouch. Both of these problems cause poor drainage from the stoma leading to excessive vomiting and acid reflux. If these problems do not respond to deflation of the band then operative re-positioning or removal of the band may be necessary. There is a 4.5 % incidence of slippage in my series
- Erosion of the band into the stomach can occur in 2.5 % of cases. This complication requires removal of the band. It can be replaced after an interval of 3-6 months. If it erodes again then the patient is considered unsuitable for gastric banding. Avoidance of over filling of the gastric pouch or having the band too tight can help prevent this problem
- The access port can drop into the abdominal cavity if the muscle layer tears, the device can become rotated in the muscle layer or the tubing can tear away from the port. These have occurred in 1.5 % of cases and the problems have required minor procedures to correct the situation
- The best way to avoid these problems is to adhere to the eating regimen detailed above. With discipline, excellent weight reduction can be achieved with patients losing an average of 35kg or 53% of excess body weight and some much more. Some patients, however, cannot exercise the necessary restraint or have trouble accepting the restrictions and with these patients, a different approach is required
Biliopancreatic diversion was developed by Professor Nicola Scopinaro from Genoa, Italy. It is a form of gastric bypass but combines mal-absorption of fats and starches with temporary gastric restriction. This is achieved by reducing the stomach capacity to 250-400cc and connecting the stomach pouch to the lower 2.75 metres of the small intestine. 4-metres of the small bowel is bypassed. This bypassed bowel carries the bile and pancreatic juices that are responsible for digesting the fat and starch in the food that we consume. A new opening is made between these two loops only 50-75 cm from the point where the small bowel joins the colon. This means that the ingested fat and starches are not digested as these juices (enzymes) only blend with the food over this short distance instead of the full 7-metre length the small bowel and therefore, approximately 80% of ingested fats and starches are not absorbed.
This results in good weight control. Patients initially find they cannot eat a great deal, which aids weight loss, but as time passes they usually are able to eat normal sized meals of most types of food.
BPD does not depend purely on gastric restriction in the long term relying more on the mal-absorption to sustain weight reduction. The mal-absorption does however have side effects. These include more frequent smelly bowel motions and the loss of nutrients that are normally absorbed with the fat that a patient eats. These include Vitamins A, D, E & K. The duodenum is bypassed so calcium and iron are not well absorbed. It is essential that patients undergoing BPD commit to taking vitamin and mineral supplements life long so as to avoid deficiencies in these nutrients. Unfortunately many patients neglect their vitamin and mineral supplements and do not return for follow up and regular blood studies. This results in vitamin deficiencies and problems such as bone softening. They also complain, long term, of the side effects of odour and frequent stools. These can be severe enough to require reversal or conversion to gastric bypass. For this reason I no longer perform this surgery even though I believe it is the most effective bariatric procedure available.
For those who undergo this procedure sunshine is important to help maintain Vitamin D levels. Protein absorption is poor so at least 100g of high quality protein must be eaten daily and fats must be strictly avoided. Fats are not absorbed and convert to oil leading to diarrhoea, incontinence and loss of nutrients. If you want to experience these side effects, try taking a course of Xenical. Despite its apparent downside, the surgery is usually well tolerated and produces excellent weight reduction.
Is discussed elsewhere in this website, Click here to go to that section.
Is discussed elsewhere in this website, Click here to go to that section.
Benefits of Weight Loss Procedures
Benefits of some of the common weight loss procedures are mentioned below.
Benefits of adjustable gastric banding surgery includes:
- Least invasive Bariatric surgery
- No stomach stapling, cutting, or intestinal rerouting
- Procedure is reversible
- Adjustable treatment customized to patient
- Adjustable for nutrition needs of pregnancy
- Lowest operative complication rate
- Lower risk of gallstones
- Low malnutrition risk
- Minimal vitamin supplementation needed
- Operation usually takes less than an hour
- Overnight hospital stay usually
- Return to work in one week
Benefits of gastric bypass surgery includes:
- Quick and dramatic weight loss
- Continued weight loss for 18-24 months’ post-surgery
- Many patients maintain a weight loss of 60-70% of excess weight 10 years’ post-op
- Improved health problems associated with severe obesity (i.e. Diabetes, high blood pressure, sleep apnoea, etc.)
- Improved mobility and quality of life
Benefits of sleeve gastrectomy surgery includes:
- Reduced stomach volume increases feeling of fullness
- Stomach functions normally allowing most foods to be eaten, just in smaller amounts
- Stomach portion that produces hunger stimulating hormone (Ghrelin) is removed.
- No dumping syndrome due to pyloric portion of stomach is left intact
- No intestinal bypass and its associated risks
- Can be performed laparoscopically
- Simpler procedure than gastric bypass
- Safer first stage procedure of two stage surgery for super morbidly obese
- Less operative time than bypass surgeries
- Less hospital stay than bypass surgeries
- No foreign bodies used such as in band surgery
Benefits of biliopancreatic diversion surgery includes:
- Best weight loss results of all surgeries
- Eating capacity is greater than other surgeries
- Continued weight loss for 18-24 months’ post-surgery
- Many patients maintain a weight loss of 75-80% of excess weight 10 years’ post-op
- Adjustable and partially reversible but only with additional surgery
- Good option for revision if other techniques have failed
- Improved health problems associated with severe obesity (i.e. Diabetes, high blood pressure, sleep apnoea, etc.) Improved mobility and quality of life