The mortality risk associated with GBP appears to be about 0.5%. Because of the increasing popularity of the procedure, some surgeons have been tempted to perform the operation without adequate training or an environment supporting the long-term follow-up care. Several studies have shown that the mortality rate from hospitals with a low experience with the procedure is far higher than the 0.5%. The American Society of Bariatric Surgeons fully supports the initiative of the Surgical Review Committee to establish rigid criteria to certify that hospitals with quality programs will be designated as a “center of excellence.” The most important questions to ask your surgeon: How many surgeries have you performed? Have you had any deaths?
The two most common causes of death after a gastric bypass are an anastomotic leak and a pulmonary embolism. An anastomotic leak can be rapidly deadly if not recognized and treated early. A “leak” occurs when intestinal fluids leak out freely into the abdomen. Symptoms of a leak may include, severe chest pain, shortness of breath, anxiety, heart palpitations and abdominal pain. Prompt treatment is critical. A pulmonary embolism is caused from a blood clot that forms in the leg that breaks off and gets lodged in the lungs. Prevention is the key to this complication. Blood thinners, leg compression devices and early walking are measures used to prevent blood clots.
Other complications include bowel obstruction, strictures, ulcers, bleeding and prolonged nausea. The open operation generally has a higher frequency of wound problems such as infections and wound hernias than the laparoscopic approach. Please see the written consent form for a more detailed written listing of complications. A frank discussion with your bariatric surgeon about the risks and benefits of surgery is critical to understanding the operation.
Post-Surgery Expectations
The length of hospital stay after the surgery varies, but usually lasts 2–7 nights. Gastric bypass is overwhelmingly successful, with many patients losing over 100 pounds within the first 18 months following surgery. Gastric bypass surgery should always be accompanied by an exercise regimen.
Undergoing a gastric bypass requires patients to commit to a new lifestyle. They will no longer be able to eat large portions of food at one sitting, nor will they be able to eat foods high in sugar or fat, which often result in gastric dumping syndrome, an unpleasant feeling of faintness caused by the sudden absorption of these foods in the shortened digestive tract. Other symptoms of “dumping” include feeling and looking flushed and some patients may feel jittery. Due to the limited amount patients can take in at any one time, they must constantly drink small amounts of water or risk dehydration.
Weight loss after bariatric surgery is described as Percent Excess Weight Loss (%EWL). Excess weight is defined as a person’s actual weight minus their ideal body weight (IBW). IBW can be estimated by the formula:
- Men: 106+6*(height in inches-60)
- Women: 100+5*(height in inches-60)
After a gastric bypass, the reported long-term weight loss varies from person to person. We can only estimate the amount of weight loss. Also, keep in mind that many weight loss operations, including the gastric bypass have significant weight loss in the short term. Long-term weight loss is much more important. On average, the %EWL after 6 months, 1year and 2 years will be 50, 70 and 80 percent. The average patient is female with a BMI of 48. There is significant variation, such that 95% of people will have lost between 95% and 60% of excess weight at 2 years.
So, a woman who weighs 325 pounds who is 5’5″ has a gastric bypass. She would be expected to lose 160 pounds at 2 years. However, she could lose as much as 190 pounds, or as little as 120 pounds. There is one predictive factor in guessing how much weight a person will lose. Patients who are very heavy and patients that are only slightly overweight, often lose weight at a predictably different rate. For instance, a patient who weighs 600 pounds, will never achieve a weight close to ideal with any bariatric operation. That person may lose 300 pounds, losing 60% of excess weight. Furthermore, a patient who weighs only 220 pounds would be expected, on average to lose a higher percentage of excess weight that a person weighing 320 pounds. That is, the skinnier you are, the more likely you can achieve a weight closer to your ideal.
It is normal and expected to gain some weight back after 2 years. The amount of weight regain is difficult to predict. One person may not regain any weight; another may regain 30 or more pounds. On average, patients regain 10-15% of their excess weight back in the long term.
Risks
The operation has a mortality rate of approximately 2% overall: 1% suffer immediate complications and death; another 1% will commonly have post-operative complications that lead to death within one month of surgery. This can be mitigated by compliance with the surgeon’s post-operative plan and using a doctor who has performed more than 200 procedures.
A full 25% of people undergoing this operation will have some form of post-operative complication (hernia, gall stones) either requiring a further procedure or change in habits. In some instances, the normal production of intrinsic factor in the stomach wall to aid in vitamin B12 absorption is decreased. This may call for either B12 injections or sub-lingual tablets for life to aid in the breakdown of food for energy.