Intestinal bypass

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Intestinal bypass is a bariatric surgery performed on patients with morbid obesity to create an irreversible weight loss, when implementing harsh restrictions on the diets have failed. [1] Jejunocolic anastomosis was firstly employed. [2] Nonetheless, it led to some unexpected complications such as severe electrolyte imbalance and liver failure. [2] It was then modified to jejunoileal techniques. Viewed as a novel form of treatment for obesity, many intestinal bypass operations were carried out in the 1960s and 1980s. [2] Significant weight loss was observed in patients, but this surgery also resulted in several complications, for instance, nutritional deficiencies and metabolic problems. Due to the presence of surgical alternatives and anti-obesity medications, intestinal bypass is now rarely used.

Contents

Anatomy of human digestive system

In the human digestive system, the stomach is responsible for mechanical and chemical digestions. The small intestine is involved in both the absorption and digestion of nutrients, whereas the large intestine is responsible for the elimination of wastes (defecation). The small intestine consists of 3 parts: duodenum, jejunum and ileum. [3] The duodenum is the first part of the small intestine and is connected to the stomach via the pyloric valve. The jejunum is the second and middle part of the small intestine. The ileum is the last part of the small intestine and is connected to the cecum, a part of the large intestine, via the ileocecal valve. [4]

Types of intestinal bypass

Procedures of intestinal bypass surgery

The intestinal bypass surgery, as the name suggests, anastomoses 14 inches of the proximal duodenum, the part of the small intestine closest to the stomach, to the 4 inches of the distal ileum, the part of the small intestine closest to large intestines. [5] This creates a blind loop and bypasses nearly 85-90 % of the small intestine. [5] As a corollary, the absorption of nutrients is greatly reduced, and thus lead to apparent weight reduction.

There are four variations of intestinal bypass. They are jejunocolic bypass, end-to-side jejunoileal bypass, end-to-end jejunoileal bypass, and biliopancreatic diversion, respectively. [5]

Jejunocolic bypass

First performed in 1963, the jejunocolic bypass is regarded as the first type of intestinal bypass surgery. This surgery anastomoses the proximal duodenum to the transverse colon (a part of the large intestine). The surgery, nevertheless, turned out to be a huge failure as patients suffered from severe electrolyte imbalance and metabolic disturbance after it. [5]

End-to-side jejunoileal bypass

The surgical procedure of end-to-side jejunoileal bypass ES JI bypass.png
The surgical procedure of end-to-side jejunoileal bypass

This type of surgery was designed to overcome the shortcomings of jejunocolic bypass. First performed in 1969, it anastomoses the end of the proximal duodenum to the side of the distal ileum. However, owing to the possibility of reflux of ileal content to the blind loop, some surgeons doubted the effectiveness of this surgery. [5]

End-to-end jejunoileal bypass

The surgical procedure of end-to-end jejunoileal bypass EE JI bypass.png
The surgical procedure of end-to-end jejunoileal bypass

This type of surgery appeared at the same time as end-to-side jejunoileal bypass. Some surgeons regarded this as a better option than end-to-side jejunoileal bypass because it prevented the reflux of ileal content to the blind loop. In order to achieve this, the end of the proximal duodenum is anastomosed to the distal ileum. The blind loop is drained to the transverse colon. [5] However, two studies revealed that both end-to-side and end-to-end jejunoileal bypass had similar weight loss effect. [5]

Biliopancreatic diversion

The surgical procedure of biliopancreatic diversion BD surgery.png
The surgical procedure of biliopancreatic diversion

First appeared in 1980, biliopancreatic diversion involves two parts: gastrectomy and intestinal bypass. Firstly, gastrectomy removes a large portion of the stomach. Reduction in stomach capacity decreases the appetite of patients. Secondly, intestinal bypass anastomoses the proximal duodenum and the distal ileum. This intestinal bypass is different from the above three bypasses in the way that the blind loop carrying bile and digestive enzymes will drain into the distal portion of the small intestine. With this technique, the absorption of nutrients, in particular, fat, can be reduced tremendously. [6]

Mechanisms of weight reduction

This surgery acts in the following ways to help patients reduce their body weight:

Induction of malabsorption

Induction of malabsorption is the most prominent effect of the surgery. The small intestines are responsible for most of the absorption of nutrients. By bypassing a considerable length of the small intestines, this type of surgery greatly reduces the absorption capacity of the digestive system. [2] Malabsorption is especially prominent in biliopancreatic diversion. Not only does it reduce the length of the small intestine for absorption, but it also drains the bile and digestive enzymes only to the distal ileum. [6] Bile is essential for fat absorption, while digestive enzymes facilitate the intake of proteins. [5] Draining them to only the distal ileum further reduces the efficiency of intestinal absorption, hence achieving the goal of weight reduction.

Conditioning of appetite

If the patients take excessive food after the surgery, they will experience abdominal discomforts such as steatorrhea and abdominal pain, [2] as patients' digestive system capacity has been reduced drastically. [2]

Selection Criteria

Intestinal bypass, in spite of its highly effectiveness in weight reduction, is a risky and irreversible. Thus, it requires rigorous assessment and selection before the surgery is carried out. The following are the normal selection criteria: [2]

This surgery serves as the LAST approach to lose weight when all other weight-losing methods have failed and at the same time, morbid obesity remains a life-threatening problem. [2] It is crucial for patients to understand all the pros and cons of this surgery, despite the weight loss they aimed for. [2]

Health impacts

Intestinal bypass surgery can lead to loss of weight effectively, but it can also lead to various complications that should not be neglected. About half of the patients who received this surgery need rehospitalization to manage the complications. [5] The expected outcomes and possible risks of the intestinal bypass surgery are shown as follows:

Expected surgical outcomes

Weight loss

It is estimated that the absorptive surface area in the small intestine can be reduced by 85% after the surgery. [5] This results in continuous malabsorption, and thus sustainable weight loss.

Metabolic benefits

  • Blood glucose level is significantly reduced. In patients with hyperglycaemia, a normal blood glucose level and a significant decline of insulin resistance are observed after the surgery, except for the cases of patients with type I diabetes. [7]
  • Serum cholesterol and lipid levels decrease, [2] which lower the risks of developing cardiovascular diseases such as atherosclerosis.

Risks of the intestinal bypass

Adverse metabolic effects

  • Diarrhoea is observed in almost all patients undertaking this surgery. The daily frequency of defecations can be up to 20. [5] This will usually affect the patients for three to six months. Electrolyte imbalance is very likely to occur owing to diarrhoea. Low serum level of potassium, magnesium and zinc were reported. [5]
  • Metabolic bone disease is more likely to occur in patients with Vitamin D deficiency before the surgery. A few cases of osteomalacia were reported. [8]

Physical weakness

Fatigue is common after the surgery due to the malabsorption of nutrients. [7]

Complications

  • Kidney stone is also an associated risk of the intestinal bypass surgery. This is mainly due to enteric hyperoxaluria. Increased absorption of oxalate in colons rises the risk of the formation of kidney stones. [5]
  • Arthritis may appear after the surgery in morbid obesity patients due to excessive immune responses to the gut bacteria. [1] The symptoms can last for three to six months. [9] However, symptoms of arthritis are not severe. [1] [9]

Dysfunctions in GI tracts

Flatulence is observed even after years of surgery. [7] Patients may suffer from persisted problems of producing flatus with foul-smell due to the accumulation of gas in the gastrointestinal tract. [7] There can also be problems of abnormal distension of the abdomen after meals. [7]

Long-term health issues

Long-term negative health effects were reported. Chronic diarrhoea is a common and frequent complication, and further leading to higher risk of proctologic diseases such as haemorrhoids. [10] More seriously, the risks of developing nephrolithiasis and chronic kidney disease are 28.7% and 9.0% respectively in the long term. [10]

Nutritional deficiencies and solutions

Nutritional deficiencies are often seen in patients after the surgery due to malabsorption. They include:

Loss of appetite

Anorexia is considered to be a normal response found after the first few weeks of the surgery but after four to six weeks, most patients gain back their initial appetite before receiving the surgery. [7]

Electrolyte imbalance

Lack of vitamins

Low serum levels of Vitamin B12, Vitamin A, Vitamin D, Vitamin E, and Vitamin K are common nutritional deficiencies after the surgery. 1000 mg of Vitamin B12 is recommended monthly, and supplements of vitamins and minerals are also recommended for the first half to full year after the surgery until the rapid weight loss period has passed. [2]

Damages to organs

Hepatic damage results from the inadequacy in nutritional supply and steatosis, where it remains as the most serious, and possibly lethal, side effect. Patients may show symptoms like nausea and emesis. Intake of alcohol is intolerable as it increases the tendency for the liver to become impaired. Incidents of death due to liver failure have also been reported. [5] By applying amino acid replacement orally right after the surgery, prevention of these liver problems may be achieved. [5]

Alternatives to intestinal bypass

Alternative surgical treatments

Due to the aforementioned complications, instead of performing the intestinal bypass surgery, gastric bypass surgery is a more commonly used bariatric surgery nowadays. Intestinal bypass surgery induces malabsorption by anastomosing proximal and distal small intestine. Yet, the small intestine has an important role in performing a wide range of important physiological and metabolic functions, such as the metabolism of lipids. Stomach, on the contrary, has a less significant role in the physiological and metabolic functions. The most prominent physiological function of the stomach is digestion, but the small intestine is also capable of digestion. [12] Thus, gastric bypass surgery does less harm to the overall metabolism of nutrients. Gastric bypass leads to weight loss by controlling the appetite of the patients, instead of inducing malabsorption. [13] As a result, the intestinal bypass is now replaced by an alternative of gastric bypass.

Anti-obesity medications

Anti-obesity medications is also a possible solution. Examples of such medications include the Orlistat, [14] which was first prescribed in 1998. In 2009, it became an over-the-counter drug after obtaining consent from the European Medicines Agency. In clinical trials, patients prescribed with Orlistat (120 mg) showed better weight loss than those without (8.76 kg vs 5.81 kg) in one year. [14] With effective medications, the obese can better control their weight without the need of undergoing a relatively high-risk surgery.

See also

Related Research Articles

<span class="mw-page-title-main">Small intestine</span> Organ in the gastrointestinal tract

The small intestine or small bowel is an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through the pancreatic duct to aid in digestion. The small intestine is about 5.5 metres long and folds many times to fit in the abdomen. Although it is longer than the large intestine, it is called the small intestine because it is narrower in diameter.

<span class="mw-page-title-main">Gastric bypass surgery</span> Type of bariatric surgery

Gastric bypass surgery refers to a technique in which the stomach is divided into a small upper pouch and a much larger lower "remnant" pouch and then the small intestine is rearranged to connect to both. Surgeons have developed several different ways to reconnect the intestine, thus leading to several different gastric bypass procedures (GBP). Any GBP leads to a marked reduction in the functional volume of the stomach, accompanied by an altered physiological and physical response to food.

<span class="mw-page-title-main">Gastrectomy</span> Surgical removal of the stomach

A gastrectomy is a partial or total surgical removal of the stomach.

<span class="mw-page-title-main">Malabsorption</span> Medical condition

Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal (GI) tract. Impairment can be of single or multiple nutrients depending on the abnormality. This may lead to malnutrition and a variety of anaemias.

<span class="mw-page-title-main">Small intestinal bacterial overgrowth</span> Medical condition

Small intestinal bacterial overgrowth (SIBO), also termed bacterial overgrowth, or small bowel bacterial overgrowth syndrome (SBBOS), is a disorder of excessive bacterial growth in the small intestine. Unlike the colon, which is rich with bacteria, the small bowel usually has fewer than 100,000 organisms per millilitre. Patients with bacterial overgrowth typically develop symptoms which may include nausea, bloating, vomiting, diarrhea, malnutrition, weight loss and malabsorption, which is caused by a number of mechanisms.

<span class="mw-page-title-main">Short bowel syndrome</span> Medical condition

Short bowel syndrome is a rare malabsorption disorder caused by a lack of functional small intestine. The primary symptom is diarrhea, which can result in dehydration, malnutrition, and weight loss. Other symptoms may include bloating, heartburn, feeling tired, lactose intolerance, and foul-smelling stool. Complications can include anemia and kidney stones.

<span class="mw-page-title-main">Vertical banded gastroplasty surgery</span>

Vertical banded gastroplasty (VBG), also known as stomach stapling, is a form of bariatric surgery for weight control. The VBG procedure involves using a band and staples to create a small stomach pouch. In the bottom of the pouch is an approximate one-centimeter hole through which the pouch contents can flow into the remainder of the stomach and hence on to the remainder of the gastrointestinal tract.

The duodenal switch (DS) procedure, gastric reduction duodenal switch (GRDS), is a weight loss surgery procedure that is composed of a restrictive and a malabsorptive aspect.

<span class="mw-page-title-main">Adjustable gastric band</span> Inflatable silicone device

A laparoscopic adjustable gastric band, commonly called a lap-band, A band, or LAGB, is an inflatable silicone device placed around the top portion of the stomach to treat obesity, intended to decrease food consumption.

<span class="mw-page-title-main">Sleeve gastrectomy</span> Surgical weight-loss procedure involving reduction of stomach size

Sleeve gastrectomy or vertical sleeve gastrectomy, is a surgical weight-loss procedure, typically performed laparoscopically, in which approximately 75 - 85% of the stomach is removed, along the greater curvature, which leaves a cylindrical, or "sleeve"-shaped stomach the size of a banana. Weight loss is affected not only through the reduction of the organ's size, but by the removal of the portion of it that produces ghrelin, the hormone that stimulates appetite. Patients can lose 50-70 percent of excess weight over the course of the two years that follow the surgery. The procedure is irreversible, though in some uncommon cases, patients can regain the lost weight, via resumption of deleterious habits, or dilation of the stomach over time, which can require gastric sleeve revision surgery to either repair the sleeve or convert it to another type of weight loss method that may produce better results, such as a gastric bypass or duodenal switch.

<span class="mw-page-title-main">Intestinal atresia</span> Medical condition

Intestinal atresia is any congenital malformation of the structure of the intestine that causes bowel obstruction. The malformation can be a narrowing (stenosis), absence or malrotation of a portion of the intestine. These defects can either occur in the small or large intestine.

Bariatric surgery is the medical term for a variety of procedures dealing with obesity. Long term weight loss through the standard of care procedures is largely achieved by altering gut hormone levels responsible for hunger and satiety, leading to a new hormonal weight set point. Bariatric surgery is the most effective treatment causing weight loss and reducing complications of obesity.

Jejunoileal bypass (JIB) was a surgical weight-loss procedure performed for the relief of morbid obesity from the 1950s through the 1970s in which all but 30 cm (12 in) to 45 cm (18 in) of the small bowel were detached and set to the side.

Revision weight loss surgery is a surgical procedure that is performed on patients who have already undergone a form of bariatric surgery, and have either had complications from such surgery or have not achieved significant weight loss results from the initial surgery. Procedures are usually performed laparoscopically, though open surgery may be required if prior bariatric surgery has resulted in extensive scarring.

<span class="mw-page-title-main">Human digestive system</span> Digestive system in humans

The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase, the gastric phase, and the intestinal phase.

<span class="mw-page-title-main">SADI-S surgery</span>

SADI-S is a bariatric surgical technique to address metabolic disorders and to lose weight. It is a variation on the Duodenal Switch surgery, incorporating a vertical sleeve gastrectomy with a gastric bypass technique.

A duodenal-jejunal bypass liner, commonly called an EndoBarrier, is an implantable medical device in the form of a thin flexible 60 cm-long tube that creates a physical barrier between ingested food and the duodenum/proximal jejunum. The duodenal-jejunal bypass liner prevents the interaction of food with enzymes and hormones in the proximal intestine to treat type 2 diabetes and obesity. The duodenal-jejunal bypass liner is delivered endoscopically and has been tested on the morbidly obese as well as obese patients with a BMI less than 40, particularly those with difficult-to-manage type 2 diabetes. Despite a handful of serious adverse events such as gastrointestinal bleeding, abdominal pain, and device migration — all resolved with device removal — initial clinical trials have produced promising results in the treatment's ability to improve weight loss and glucose homeostasis outcomes.

Ileal Interposition is a Metabolic Surgery procedure, used to treat overweight diabetic patients through surgical means. First presented by the Brazilian surgeon Aureo De Paula in 1999, this technique is applied by placing ileum, which is the distal part of the small intestine, either between stomach and the proximal part of the small intestine (1) or by placing the ileum to the proximal part of the small intestine without touching the natural connections of the stomach (2). There are 2 different versions of the operation. Sleeve gastrectomy procedure is standard for both of the versions.

Stomach Intestinal Pylorus-Sparing (SIPS) surgery is a type of weight-loss surgery. It was developed in 2013 by two U.S. surgeons, Daniel Cottam from Utah and Mitchell S. Roslin from New York.

Edward Eaton Mason was an American surgeon, professor, and medical researcher who specialized in obesity surgery. He is known for developing restrictive gastric surgery for morbidly obese patients. Mason introduced the first gastric bypass surgery in 1966 and was the inventor of the first vertical banded gastroplasty surgery in 1980.

References

  1. 1 2 3 Bray, G A; Barry, R E; Benfield, J R; Castelnuovo-Tedesco, P; Rodin, J (1976-07-01). "Intestinal bypass surgery for obesity decreases food intake and taste preferences". The American Journal of Clinical Nutrition. 29 (7): 779–783. doi: 10.1093/ajcn/29.7.779 . ISSN   0002-9165. PMID   937232.
  2. 1 2 3 4 5 6 7 8 9 10 11 Herbert, Carol (July 1975). "Intestinal bypass for obesity: the family physician's concern". Canadian Family Physician. 21 (7): 56–59. PMC   2274667 . PMID   20469212.
  3. ↑ Moore, Keith L. (September 2017). Clinically oriented anatomy. ISBN   9781496347213. OCLC   978362025.
  4. ↑ Drake, Richard L. (2019-02-22). Gray's anatomy for students. ISBN   9780323393041. OCLC   1085137919.
  5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Anders Sylvan (1995). Jejunoileal bypass for morbid obesity : studies of the long-term effects. Umeå universitet, Kirurgi. OCLC   909363268.
  6. 1 2 "Bariatric Surgery Procedures".
  7. 1 2 3 4 5 6 7 8 DeWind, Loren T.; Payne, J. Howard (2014-09-03). "Intestinal Bypass Surgery for Morbid Obesity: Long-Term Results". JAMA. 312 (9): 966. doi:10.1001/jama.2014.10853. ISSN   0098-7484. PMID   25182115.
  8. ↑ Compston, JE; Vedi, S; Pitton, L; Watson, GJ; Woodhead, JS; Scopinaro, N (1984). "Vitamin D Status and Bone Histomorphometry after Biliopancreatic Bypass for Obesity". Clinical Science. 67 (s9): 73P.2–73P. doi:10.1042/cs067073pa. ISSN   0143-5221.
  9. 1 2 Wands, J. R.; La Mont, J.T.; Mann, E.; Isselbacher, K.J. (1976-01-15). "Arthritis Associated with Intestinal-Bypass Procedure for Morbid Obesity". New England Journal of Medicine. 294 (3): 121–124. doi:10.1056/nejm197601152940301. ISSN   0028-4793. PMID   1105187.
  10. 1 2 Vitiello, Antonio; Vincenzo, Pilone; Formato, Antonio; Izzo, Giuliano; Ferraro, Luca; Forestieri, Pietro (2018-10-20). "Ten years of follow-up of bilio-intestinal bypass: is malabsorption necessary for long-term metabolic results?". Langenbeck's Archives of Surgery. 403 (7): 873–879. doi:10.1007/s00423-018-1717-7. ISSN   1435-2443. PMID   30343414. S2CID   53042672.
  11. ↑ Haria, Dhiren M.; Sibonga, Jean D.; Taylor, Harris C. (September 2005). "Hypocalcemia, Hypovitaminosis D Osteopathy, Osteopenia, and Secondary Hyperparathyroidism 32 Years after Jejunoileal Bypass". Endocrine Practice. 11 (5): 335–340. doi:10.4158/ep.11.5.335. ISSN   1530-891X. PMID   16191495.
  12. ↑ Widmaier, Eric P. (2015-11-03). Vander's human physiology : the mechanisms of body function. ISBN   9781259294099. OCLC   951753471.
  13. ↑ Weledji, Elroy Patrick (2016). "Overview of gastric bypass surgery". International Journal of Surgery Open. 5: 11–19. doi: 10.1016/j.ijso.2016.09.004 . ISSN   2405-8572.
  14. 1 2 Hall, Mark (January 2009). "Orlistat". Practical Diabetes International. 26 (1): 341–342. doi:10.1002/pdi.v26:1. ISSN   1357-8170.
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