Weight loss through Bariatric Surgery

Introduction

Severely obese persons often cannot be helped with calorie-restricted diet and exercise even when supplemented with non-prescriptive weight loss drugs. Managing obesity can often be done with surgery which is considered the last resort of choice. This drastic solution is called bariatric surgery whose objective is to reduce stomach size and thereby reduce food intake.

The process involves either of two main procedures.[1].

(1) Malabsorptive procedures: reducing stomach size while creating malabsorption by altering how the nourishment is achieved. This has become a rare procedure due to its inherent risks for inducing severe nutritional deficiency.

(2) Restrictive procedures: This involves simply reducing the size of the stomach and the most widely performed bariatric surgery among severely obese patients.

 Who should undergo bariatric surgery?

As a last resort to weight loss, the U.S. National Institutes of Health suggests that obese people with a body mass index (BMI) of 35 suffering co-morbidities like diabetes or heart diseases, and those with BMI of 40 without diagnosed co-morbidities should strongly consider bariatric surgery. Recent medical research suggests that bariatric surgery could be most suitable for obese persons with a BMI of 35 to 40 without co-morbidities or a BMI of 30 to 35 diagnosed with co-morbidities. [1] In addition, the National Institute of Diabetes and Digestive and Kidney Diseases has indicated that bariatric surgery is most suitable for women who are at lest 80 lbs overweight and men who are at least 100 lbs overweight.[5]

Obese persons suffering co-morbidities like diabetes mellitus, hyperlipidemia, impaired glucose tolerance, hypertension, and obstructive sleep apnea can be considered candidates for bariatric surgery. One who is seriously considering it should consult with his or her doctor for the surgical options and a full disclosure of its potential post-surgical complications. [2]

How malabsorptive bariatric surgery works

Biliopancreatic diversion (BPD)

This is complex surgery where part of the stomach is resected to create a smaller pouch and where the distal part of the small intestine bypasses the jejunum and duodenum before being reconnected to the resected stomach pouch. BPD is now rarely performed mostly due to its high risk of complications such as gallstones and several nutritional deficiencies that, without supplementation, could lead to osteoporosis and anemia. [1]

How restrictive bariatric surgery works

A smaller stomach pouch gets full faster, and a feeling of satiation sets in so you eat fewer food portions over a shorter period of time and you lose weight progressively. Restrictive bariatric surgery reduces the size of the stomach through laparoscopic tools is the most popular and often involves the following.

(1) Sleeve gastrectomy

The stomach is surgically reduced to around 15% of its former size and using surgical staples, or sutures or both, leaves the stomach looking like a banana-shaped tube and is irreversible. As the stomach size is reduced, the portion where hormones are produced to stimulate hunger (Ghrelin) is likewise removed and has been shows to be effecting moves patients with a BMI higher than 55. A majority of patients undergoing this surgical process can expect to lose about 30% to 50% of their excess body weight in 6 months to a year. [1]

(2) Adjustable gastric banding

A silicone band that can be inflated with 4 to 12cc of saline solution is placed around the stomach. When inflated, it constricts the stomach to create a smaller stomach pouch at the top section, decreases the size of the passage between this pouch and the lower stomach and slows food passage between the two. Once food is digested in the upper stomach pouch, no further digestion takes place in the lower stomach and the digested simply passes to the intestines. [1]

 The resulting smaller stomach pouch holds about ½ to 1 cup of food while the entire stomach could hold 6 cups. As a reversible and adjustable process, you can expect a few visits back to the surgeon to adjust the band with the injection or suction of saline solution to achieve optimal constriction. The band is tightened or loosened so that hunger is best controlled but not too tight for digested food not to flow freely. [7]

Obese people can expect to lose 33% to 50% of their excess weight after undergoing this procedure and can be achieved slower than with Gastric Bypass surgery over a 3-year period. [6] In addition, gastric banding can be reversed once the obesity is corrected or when the proper BMI is achieved, if the patient so desires. [8].

(3) Gastric Bypass Surgery

The most popular form of gastric bypass surgery is the Roux-en-Y gastric bypass where a small stomach pouch is formed using a stapler device, and connected to the distal small intestine. The upper section of the small intestine is then re-connected to form a Y-shaped configuration. About 140,000 gastric bypass surgery has been done as of 2005 to make it the most widely used bariatric surgery. But its success has been largely due to the stringent post-surgery compliance to a prescribed diet and eating pattern. [1]

Health Benefits

Medical studies have shown that bariatric surgery can cause significant long-term weight loss efficacy, recovery from diabetes, improvement in cardiovascular risk factors, and halving statistical mortality rates reduced from 40% to 23%. [2] In addition, the more popular forms of bariatric surgery have been known to lose about 40% to 50% of unwanted weight. That's because the smaller stomach resulting from the surgery makes you feel full faster every meal and thus, decreases your food cravings and consumption.

Complications and side effects

Complications from any kind of surgery are high and barbaric surgery complications are common. A study of 2522 insurance claims showed that about 22% suffered initial complications while 40% suffered complications within 6 months of surgery. Some of the more common complications include:

-Diarrhea and bloating after meals (gastric dumping syndrome), requiring medication or smaller meals: 20%
-Leaks at the surgical site (12%),
-Incisional hernia (7%),
-Surgical wound Infections (6%)
-Pneumonia: 4%

Mortality rate among patients with no known co-morbidities is small at 0.2%. Most of complications have been observed to be common among patients aged over 40. However, they were significantly reduced when bariatric surgery is performed by seasoned doctors or surgeons. [3] A study on the end-point safety of bariatric surgery shows that mortality, serious complications, re-interventions and further hospitalization occurred in 1.0% of patients who underwent laparoscopic adjustable gastric banding, 4.8% in laparoscopic gastric bypass, and 7.8% in open gastric bypass. [4] Gastric banding procedure has shown the least complication rate. But as with any surgery, band gastric surgery carries the same risk of wound infections and minor bleeding which can often be treated with antibiotics.

 Conclusion

If you are obese or overweight with a body mass index (BMI) of 35 or higher, undergoing restrictive bariatric surgical procedure is generally safe when performed by experienced surgeons or healthcare professionals specializing in the process. In February 2011, the FDA reduced the recommended BMI threshold to 30 for those considering the process. This opened up the surgical weight loss solution even to those with moderate obesity. If you are even moderately obese and have been going through diet and exercise regimens for years with little or no success, a bariatric surgery such as gastric banding or gastric bypass surgery can be your most effective and long lasting weight management solution.

Sources:
[1] http://www.news-medical.net/health/Bariatric-Surgery-What-is-Bariatric-Surgery.aspx
[2] http://www.nejm.org/doi/full/10.1056/NEJMe0904837
[3] http://www.news-medical.net/health/Bariatric-Surgery-Side-Effects.aspx
[4] http://www.nejm.org/doi/full/10.1056/NEJMe0904837
[5] http://www.nlm.nih.gov/medlineplus/weightlosssurgery.html
[6] http://www.nlm.nih.gov/medlineplus/ency/article/007388.htm
[7] http://www.webmd.com/diet/weight-loss-surgery/gastric-banding-surgery-for-weight-loss
[8] http://www.seaviewsurgeon.com.au/surgery-treatments/gastric-banding/