Surgical Treatment of Obesity

Surgical Treatment of Obesity
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Abstract
Obesity is considered to be one of the most complex problems in the developed world although cases of obesity have increasingly been recorded in developing world as well. This observation has been due in part to the effect of globalization that has seen significant changes in lifestyles among individuals in the developing countries. Weight-loss surgical operations have become the main interventions for the management of morbid obesity especially for individuals whom other conservative measures such as exercise, diet and medications for obesity have failed to work. Among the most common weight-loss surgical methods (bariatric surgery) used today can be categorized to either restrictive, malabsorptive or a combination of both restrictive and malabsorptive procedures. Malabsorptive methods alter the manner in which the digestive system functions while restrictive procedures significantly reduce the stomach size so as to hold lesser food while ensuring that the digestive functions remain unaffected. This paper explores in detail the various surgical procedures that have been used in the treatment of obesity and points out some of the challenges and the future interventions to improve treatment options for obesity.

Table of Contents Page
Abstract…………………………………………………………………………....2
Table of contents…………………………………………………………………..3
Introduction………………………………………………………………………..4
Bariatric surgery in the treatment of obesity............………………………………5
Malabsorptive surgery……………….…………………………………………….5
Rationale of malabsorptive surgery…………….………………………………….8
Benefits for malabsorptive surgery….......................................................................9
Risks in malabsorptive surgery………………….…………………………………10
Malabsorptive surgical procedure…………….……………………………………11
Restrictive Surgery……………………..…………………………………………..13
Procedure of restrictive surgery............................………………………………....15
Benefits of restrictive surgery…..………………………………………………….19
Risks of restrictive surgery….…...............................................................................20
Recommendations and future direction…..………………………………………...20
Conclusion.................………………………………………………………………21
Bibliography..……………………………………………………………………...23
Appendix….………………………………………………………………………..27
List of Figures…..………………………………………………………….............27
List of Tables…..…………………………………………………………………..28
List of Abbreviations…..…………………………………………………………..29
Surgical Treatment of Obesity
Introduction
It is estimated that over 50 percent of the individuals in the U.K are overweight with a body mass index (BMI) of more than 25 and above than 30 kg/m2 (BMJ 2008). The cases of obesity continue to increase in developed countries as well as developing countries perhaps due to the change in lifestyles such as lack of exercise and eating behaviors (Larsen & Berry 2010). In 2008 alone, there were 3.71 million Australians who were obese, 1.76 million among then being males and 1.95 being females (O’Brien, 2008). These figures were higher than the numbers recorded in 2005 with a record of 14.5 percent increase (O’Brien 2008). Surgical procedures remain the method of choice for the management of morbid obesity in ideal patients because of its potential to achieve long-term control of overweight and related problems such as type II diabetes as well as metabolic syndrome (Larsen & Berry 2010). Weight-loss surgical procedures are collectively known as bariatric surgery which are further classified into malabsorptive, restrictive and a combination of malabsorptive and restrictive interventions (Ashrafian et al 2008). While modifications in individual lifestyles such as exercise, diet and other behavioral changes are still widely being used in the treatment of obesity, these interventions only lead to a modest loss in weight (Maggard et al 2005) The achievements of antiobesity medications have also not reached the effectiveness required in the management of the disease and only results to a decrease in 3-5kg of the individual weight (Padwal & Sharma 2009). Another serious problem associated with drugs lies is the high cost of buying the medications and the low tolerance and persistence levels of below 2 percent after 2 years of treatment (Padwal & Sharma 2009). Bariatric surgery in contrast to the use of drugs and changes in lifestyle achieves 33 percent weight reduction after some years and 14-25 percent of weight reduction after 10 years (Padwal & Sharma 2009). Therefore, bariatric surgery remains to be the sole option for effective treatment of morbid obesity.
Bariatric Surgery in the Treatment of Obesity
Intensified efforts in surgical treatment of overweight problems have emerged due the increased numbers of individuals becoming obese. These efforts have resulted to the development of a number of procedures which are used to manage obesity (Maggard 2005). Bariatric surgery which was first tried in 1954 involves the introduction of a bypass on the large segment of the ileum known as the jejunoileal bypass (Scott et al 1970). Other procedures in bariatric surgery however do not involve bypasses and bands and staples are used instead. Bariatric surgery has widely been used to prevent the risks associated with cardiovascular diseases and prevent metabolic syndrome. Other than obesity, bariatric surgery has also been employed in the treatment of gastroesophageal reflux disease (GERD) whose occurrence seems to be parallel with that of obesity (Prachand & Alverdy 2010). Ashrafian et al (2008) have observed that obesity contributes to a number of risk factors that lead to arthrosclerosis and eventually cardiovascular diseases. Obesity also leads to complications such as insulin resistance, hypertension and dyslipidemia (Ashrafian et al 2009). With bariatric surgery, patients can achieve up to 40 percent of weight loss hence reduce risks of cardiovascular diseases (Ashrafian et al 2008). The general benefits of bariatric surgery in relation to cardiovascular disease are summarized in Diagram 1.1. While bariatric surgery promises good result among a large number of individuals with morbid obesity, the BMJ (2008) indicates that the benefits of bariatric surgery may not be enjoyed for long and health problems and weight again might recur.
1. Malabsorptive surgery (Gastric Bypass)
Malabsorptive surgery, also known as gastric bypass surgery is an example of bariatric surgery which alters the entire process of digestion. Bariatric surgery remains to be the most effective method for the treatment of morbid obesity especially among individuals who have failed to respond to conservative measures such as exercise, diet and other medications for obesity management. Two main types of gastric bypass (malabsorptive) surgery have been recognized in the management of obesity. These methods are Roux-en-Y and biliopancreatic diversion (Kermali et al 2010). However, all the methods of gastric bypass involve the bypassing of some part of the small bowel by some degree. This is the reason as to why these procedures are generally referred to as malabsorptive methods since they involve some kind of bypassing of the small intestine which absorbs the nutrients. Other gastric bypass surgical procedures will however involve the stapling of the stomach so as to create a tiny pouch which will act as the new stomach (Singhal, Schwenk & Kuma 2007). While gastric bypass procedures are malabsortive, they may also become restrictive due to the reduction in the size of the stomach. The amount of food eaten is greatly reduced because of the reduced stomach size (Pournaras & le Roux 2009). Although malabsortive procedures result to significant weight reduction as compared to exclusively restrictive methods, Aasheim et al (2008) have noted that malabsorptive procedures are often associated with a number of risks which include nutritional deficiencies. A number of differences are noted between Roux-en-Y gastric bypass and biliopancreatic diversion gastric bypass which are the two main types of malabsorptive surgical procedures and physicians and patients will have to make decisions on which type of surgical method will be of most benefit to individual patients (Friedenberg 2002).
a) Roux-en-Y gastric bypass (RLYGB)
Roux-en-Y gastric bypass is a common method of bariatric surgery which can be said to be both restrictive and malabsorptive. Roux-en-Y gastric bypass results to the achievement of up to two-thirds weight reduction of the extra weight among obese individuals in just two years Stevens 2002).. The procedure of carrying out Roux-en-Y gastric bypass involves stapling of apportion of the stomach in order to create a small pouch which can hold lesser food followed by the reshaping of the portion of the ileum into a Y-shape hence the name “Roux-en-Y” gastric bypass as shown in Fig 1.1. The Y-shaped portion of the small intestine is then joined to the stomach pouch so that whenever food is in the process of being digested, it directly travels into the lower portion of the small intestine bypassing the first portion of the intestine (duodenum) and then the first portion of the second section of the intestine (jejunum). In brief, the rationale of bypassing these sections of the small intestines is to prevent the traffic of nutrients and calories which are absorbed into the circulatory system.
It is recommended that Roux-en-Y gastric bypass be carried out by the use of a laparoscope instead of performing open surgical procedures among some patients (Stevens, 2002). The Roux-en-Y gastric bypass procedure employs a number of several small incisions instead of making a large cut through the abdominal region. The procedure can also employ the use of 1-3 laparoscopes together with the small incisions. Laparoscopes are tiny tubes which have video cameras implanted into them as shown in Fig 1.2. The video cameras enhance the visualization of the internal parts of the abdomen during the surgical process (Friedenberg 2002). While carrying out the surgical operation, the doctor watches the TV monitor in order to see the internal positioning of the organs. The technique is not recommended for individuals with a BMI of over 60 or those who have had some forms of abdominal surgical operations (Stevenss 2002). Laparoscopic techniques allow the physicians carrying out the surgical operation to make a number of even smaller cuts. In general, laparoscopic gastric bypass reduces the time a patient might stay in the hospital thus resulting to quicker recovery compared to open procedures (Gijarro 2007).
b) Biliopancreatic diversion (BPD)
Similar to Roux-en-Y gastric bypass, biliopancreatic diversion (BPD) can be said to be both malabsorptive and restrictive although it is much complicated compared to the Roux-en-Y gastric bypass procedure (BMJ 2008). BPD involves the removal of a large section of the lower gastric region. This leaves the smaller portion of the stomach still directly connected to the last portion of the jejunum as shown in Fig 1.3. Usually, as food is being digested, it entirely bypasses the jejunum and the duodenum leading to severe nutritional deficiencies. As for this reason, BPD is not much recommended for the treatment of obesity. There is another procedure known as the duodenal switch which is a variation of the BPD procedure. In this procedure, much of the stomach as well as the valves which are responsible for the control of food release into the small intestines are retained (BMJ 2008). This procedure prevents the problem of dumping syndrome that can lead to serious diarrhea and vomiting. Usually, a small portion of the duodenal region is also retained.
Rationale of Malabsorptive surgery
Malabsorptive surgical procedures aim to change the complete process of digestion. The procedures achieve their effectiveness by in different ways dependent on the type of surgical method used. In normal humans, the stomach is known to be the store of all the entire food as well as liquids taken by individuals (Friedenberg 2002). For the stomach to work effectively, the upper portion of the stomach has to relax and admit more and more volumes of the material swallowed (liquids or solids). The lower portion of the stomach is committed to mixing up the food content which can be either solid or liquid with the digestive juice containing acids and a mixture of enzymes (BMJ 2008). After food has been worked up by the enzymes and the digestive acid, the stomach finally empties all its contents into the receiving part of the small intestines (Shield, Crowne & Morgan 2008). The received content is then digested by a number of enzymes present in the small intestines and is the taken to the pancreas for further digestion by the lipase enzymes. In the liver, the digested food material is stored in the form of glycogen which is a reservoir for energy whenever it’s required. The entire process altered by malabsorptive surgical operation can be shown in Fig 1.6 where key organs in human digestive system are clearly illustrated (American Society for Metabolic & Bariatric Surgery 2005). In brief, the goal of bariatric surgery in general is to reduce the total size of gastric store or reservoir regardless to the presence or absence of any degree of malabsorption (BMJ, 2008). With bariatric surgical operation, patients experience excellent improvement in their eating styles thus reducing the caloric intake (Wee 2009). The procedure also ensures that patients have a reduced tendency of eating large sizes of foods at a fast pace and that patients chew the food completely before swallowing (American Society for Metabolic & Bariatric Surgery 2005).
Benefits of Malabsorptive (Gastric Bypass) Surgery
Gastric bypass is recommended for individuals with a BMI of over 40 and male subjects weighing over 100 pounds or women with weights of over 80 pounds above their required body weights. Mason et al (2005) found out that surgical operation was the more effective intervention than nonsurgical methods to treat obesity and other cormobid conditions among individuals with BMI greater than 40kg/m2. Individuals with BMI ranging between 35 and 40 and with some other complications such as sleep apnea, type II diabetes and heart disease are also recommendable to receive gastric bypass (Schernthaner & Morton 2008). Gastric bypass which is one type of bariatric surgery offers a number of benefits to the recipients compared to AGB (Bowne et al 2006). These benefits include decreased levels of cholesterol, sugar, blood pressure, cardiac workload and sleep apnea (Still et al 2007). While surgical treatment such as gastric bypass for the treatment of obesity may not be a universal solution for all individuals, the procedure can be of much help if individuals strictly follow the doctors’ recommendations following surgery (Scherthaner & Morton 2008). While gastric bypass surgical operations are comparatively costly than malabsoptive techniques, LRYGB has higher success rates of 32 percent in weight reduction compared to 19.6 percent with LAGB (Campbell et al 2010).
Risks of Malabsorptive surgery (Gastric Bypass)
There are always risks associated with the gastric bypass procedures and patients should be educated about these risks. Infection of the incised area is one of the most common risks experience by a number of patients who have already undergone the procedure (BMJ, 2008). This risk can however be prevented by the use of antibiotics and the maintenance of good hygiene during surgical operation, while the patient is being hospitalized and even when the patient has been released from the hospital (Campo et al 2008). Blood clots which can often turn fatal through embolism are other potential risk associated with gastric bypass (Kapa, Sert Kuniyoshi & Somers 2008). Pneumonia, gallstone development and bleeding ulcers are also some of the possible risks which can be potentially life-threatening (BMJ, 2008). Malabsorptive symptoms can also be severe with Roux-en-Y gastric bypass. These symptoms might lead to increase nutrient (fat soluble vitamins A, D, E and K) and increased chances of developing anemic conditions due to the failure to absorb calcium, vitamin B12 and iron. Failure of the body to absorb calcium will eventually result into the development of osteoporosis and other bone diseases of metabolism. While there are a number of risks observed among patients undergoing RLYGB, Collins et al (2007) observed that the risks of gastritis is higher (71 percent) with loop gastroenterostomy than in RLYGB with 13 percent risk (BMJ 2008).
There are also increased risks of developing dumping syndrome because food contained in the stomach moves at a faster pace into the intestines. The symptoms for this complication include weaknesses, sweating, nausea, diarrhea and fainting (Campo et al 2008). Risks of requiring another surgical operation due to the development of gallstones are also common. Perhaps one of the most serious complications of gastric bypass is the problem associated with stomach leakage which can lead to the development of peritonitis (Bult, van Dalen & Muller, 2008, p.140). In peritonitis, the peritoneum, which is a smooth membrane lining the abdominal cavity is highly inflamed resulting into severe pain. Apart from the common risks that always present in large numbers of patients, there are also specific medical risks that are dependent on the individual himself or herself (BMJ 2008). Table 1.1 provides a summary of the complications patients might experience shortly after AGB and RLYGB and later after the operation (Friedenberg 2002).
Gastric Bypass (malabsorptive surgical) Procedure
Like any other surgical operation, gastric bypass requires that a patient is hospitalized and this procedure may differ from one patient to another depending on the type of procedure being carried out and the competences of the physician. Usually, patients are induced to sleep prior to the surgical procedure and general anesthesia is administered. Specifically, the process follows the following steps. A patient is asked to take off his or her clothes and wear a gown which is provided. An IV line is then started in the patient’s arm or hand. A patient is then positioned to lie on his or her back on the operating table. A urinary catheter may then be fixed into the bladder to collect any urine (BMJ 2008). The role of anesthesiologist in gastric bypass operation is to ensure that the heart rate, breathing levels, blood pressure and the amount of available oxygen is closely monitored during the entire process of surgical operation. It is important that the skin surrounding the area to be operated is free from germs to avoid other post-surgical infection. This can be done by cleaning the area using an antibiotic solution (BMJ 2008). The physician may then make a deep incision into the abdomen in the case of open procedures. However, for laparoscopic procedures, a physician makes a number of small cuts in the abdominal area. The introduction of carbon dioxide is crucial so as to inflate the space in the abdomen foe the appendix and other organs to be visualized with ease using a laparoscope (University of Chicago Medical Center 2010). Open procedures may require that the abdominal muscles be separated and the space in the abdomen be open. A physician may be required to insert the laparoscope including other tiny instruments into the abdomen (Stevens 2002).
Roux-en Y gastric bypasses necessitates the physician to staple together the top part of the stomach so as to allow for the creation of a new pouch for the stomach. In this procedure, the other portion of the stomach will entirely be separated from the newly created small pouch and the closed by the use of staples. The other remaining portion of the stomach will still continue to produce digestive juices containing critical enzymes for digestion. Part of the small intestines will assume the “Y” shape and will be joined to the pouch. Biliopancreatic diversion involves the removal of a larger portion of the lower stomach while the smaller portion of the stomach is left intact joined to the end of the small intestine directly. Duodenal switch procedure requires that a physician retains much of the stomach as well as the valves which control food release into the small intestines (BMJ 2008). In addition, a small portion of the duodenum will also be left intact. After the procedure, it will be necessary to allow draining in the incised region in order to remove the fluid. The cut section is the closed using surgical staples or stitches and then a sterile dressing or bandage is applied.
2. Restrictive surgery (Gastric stapling)
Gastric stapling represents one type of bariatric surgery carried out in order to limit the quantity of food individuals can eat. Three major types of gastric stapling have been recognized: gastric banding surgery, vertical banding gastroplasty and adjustable gastric banding. Gastric banding surgery ensures that the stomach is left intact and no section of the stomach is cut out. In this procedure, staples or even bands (as the name suggests), are used to divide the stomach into two distinct parts. One of the divided parts comprise of a very tiny pouch which is capable of holding about an ounce of food. Food in the newly created stomach will then empty into the closed-off section of the stomach before resuming the normal process of digestion (Shield, Crowne & Morgan 2008). With time, the small pouch will then expand to even contain about 2-3 ounces of food. Since the stomach size is significantly reduced, the method is often referred to as restrictive surgical procedure. Upon successful gastric stapling or banding, patients can eat a limited amount of food and the food should be chewed properly. Otherwise, if more than one ounce of food is consumed than the small pouch can hold, patients will eventually exp...