Treatments → The Benefits and The Risks

Inherent Benefits and Advantages of the Bariatric Surgeries

Gastric Restrictive Procedure

  • The primary advantage of this restrictive procedure is that a reduced amount of well-chewed food enters and passes through the digestive tract in the usual order. That allows the nutrients and vitamins (as well as the calories) to be fully absorbed into the body.
  • After 10 years, studies show that patients can maintain 50% of targeted excess weight loss.

Malabsorptive Procedure

  • These operations often result in a high degree of patient satisfaction because patients are able to eat larger meals than with a purely restrictive or standard Roux-en-Y gastric bypass procedure.
  • These procedures can produce the greatest excess weight loss because they provide the highest levels of malabsorption.
  • In one study of 125 patients, excess weight loss of 74% at one year, 78% at two years, 81% at three years, 84% at four years, and 91% at five years was achieved.
  • Long-term maintenance of excess body weight loss can be successful if the patient adapts and adheres to a straightforward dietary, supplement, exercise and behavioral regimen.

Combined Restrictive & Malabsorptive Procedure

  • The average excess weight loss after the Roux-en-Y procedure is generally higher in a compliant patient than with purely restrictive procedures.
  • One year after surgery, weight loss can average 77% of excess body weight.
  • Studies show that after 10 to 14 years, 50-60% of excess body weight loss has been maintained by some patients.
  • A 2000 study of 500 patients showed that 96% of certain associated health conditions studied (back pain, sleep apnea, high blood pressure, diabetes and depression) were improved or resolved.

A Discussion of Risks and Complications: A to Z

The risks of gastric bypass surgery can be viewed a number of different ways. The NIH Consensus Development Panel of 1991 concluded that, in general, the risk of obesity surgery is less than the risk of being morbidly obese. In fact, if one looks at the figures of over 400,000 people dying of obesity-related illnesses each year versus the complications of gastric bypass surgery, the overall risk is small. For the individual patient, however, the risk may be quite significant and therefore weighing the risks versus the benefits is important in every operation and gastric bypass is no exception. The following list includes of the potential complications, from “a to z”, of gastric bypass surgery but is not all-inclusive. What we try to do with this list is to include all of the more common potential complications as well as some of the less common, but perhaps more significant complications. It should be emphasized that this is not necessarily an all inclusive list. It should also be emphasized that the sicker the patient, the more likely there are to be complications from an operation. Again, this is a general rule and not to be held fast by each individual occurrence. You should fully discuss ANY questions you have with your surgeon!


a) Death: This complication is self-explanatory but it needs to be understood that the potential for death is not only from such things as drug interactions but also can be caused by other such complications as noted below, i.e., heart attack or stroke. In general, throughout the United States, the number most commonly quoted as the death rate from obesity surgery is 1 out of 200 patients. For surgical complications, the death rates are generally discussed as any death occurring within a 30-day time period following surgery. Our death rate is less than 1 patient in 2,000 laparoscopic gastric bypass surgeries.

b) Injury to intestines, stomach, possibly requiring repair: This complication can occur during any abdominal operation and is more likely to occur if the patient has already had prior surgery which has caused scarring or adhesion formation. Even without prior surgery, there is a risk to other internal organs during an operation.

c) Rupture of stomach pouch: The main portion of the stomach is separated from the “new stomach”. Because of this separation, there is no other outlet if the main stomach becomes distended or dilated and there may be a disruption or rupture of that organ. This is an unusual or rare complication and may occur more frequently with certain other medical conditions and therefore a tube gastrostomy may be placed, in this high-risk population, to try to avoid this potential complication.

d) Injury to spleen possibly requiring removal: The spleen is in very close proximity to the part of the stomach where the staple lines are placed. In some instances, the spleen is very tightly adhered and, in mobilizing these organs, injury may occur. Again, this is an unusual situation.

e) Blood clots, pulmonary emboli: Blood clots can form in the legs and pelvis and break off and go up through the heart and into the lungs. This can cause difficulty in breathing and can be a cause of death. The main ways of reducing this potential complication are using compression devices on the legs, early and aggressive ambulation, and blood thinning medication. Patients who are relatively less mobile pre-operatively, have clotting abnormalities or have heart or venous disease are more at risk.

f) Stroke: This is an unusual complication from gastric bypass surgery but can occur in anyone following surgery. There is no more likelihood from gastric bypass than from any other types of surgeries.

g) Anemia: Gastric bypass surgery does entail some blood loss although is not usually of a significant nature, that is, it usually does not require major intervention or transfusion. Patients post-operatively do not absorb iron as well as a normal GI tract and therefore anemia may result. It is important to follow the instructions of the program to take iron supplementation in the correct form.

h) Hemorrhage: All surgery has the risk of bleeding. Hemorrhage is more significant bleeding. The risk of transfusion from a gastric bypass operation is relatively low. It is possible that an additional operation may be needed if hemorrhage does occur.

i) Disruption of the incision: Wound infections and fluid collections can occur at any incisions and this may cause the incisions to open up and cause drainage.

j) Pneumonia: This is an infection in the lungs and is relatively unusual finding following gastric bypass surgery but may be very serious if it occurs. The best way to avoid this is to be up and active with walking, coughing and deep breathing.

k) Abscess (external and intra-abdominal) and wound infections: Abscesses can occur. The most common places they are found are in the subcutaneous (skin) wounds themselves. The wound infections are, at times, painful, red, and warm, but most of the time, are not life-threatening. Most wound infections are treated by simply opening the wound and allowing the drainage to come out with the wound healing secondarily over time. Intra-abdominal abscesses are much less common but can occur with any intra-abdominal surgery, especially when the GI tract is opened. This may require another operation or drainage procedure in the x-ray department.

l) Heart attack: An unusual complication following gastric bypass surgery, however, many patients having this procedure have cardiac disease either known or unknown. Morbid Obesity, after all, is a risk factor for cardiac disease as is Diabetes, High Blood Pressure and High Cholesterol.

m) Bowel obstruction: This complication can occur with any intra-abdominal operation, especially operations performed on the small bowel. Mostly, they are caused by internal hernias or adhesion formation (scar tissue). If this occurs, another operation is usually needed.

n) Hypoproteinemia: This is an unusual occurrence following gastric bypass surgery in the manner we perform the operation. This would be more likely to occur with malabsorptive operations or if patients are having difficulty with prolonged nausea, vomiting, or stricture formation. It is extremely important for patients to maintain an adequate protein intake, even to the point of supplementation in the early postoperative period.

  • Vitamin Requirements: This is a subdivision we will put under hypoproteinemia because it too deals with the absorption issue. Vitamin supplementation is very important. Because there is less food consumed, there will not be adequate vitamin intake from the food alone. Vitamin and mineral replacement is important, for life. This includes High Potency Multi-vitamins, Calcium, B12 and Iron.

o) Edema: Edema is generalized swelling and many patients exhibit this in one form or another, especially immediately after surgery since we give intravenous fluids to support patients from the stress of surgery. Most often the swelling or edema resolves over the ensuing week following surgery, however, there are situations where edema may last longer. If someone experiences unilateral or one-sided edema or swelling of a lower extremity, it may be due to blood clots.

p) Incision hernia: This is an unusual complication following laparoscopic surgery but can occur. With open surgery the risk is perhaps as great at 20% with upper midline incisions. With laparoscopic surgery, the risk goes down to less than 1 in 2,000.

q) Leakage from anastomosis: We cut, staple and/or sew the small intestine and stomach in a number of different areas. Each of these areas need to heal. Patients who are morbidly obese heal more slowly because of some complicating wound issues. Patients with diabetes and sleep apnea, for example, heal more slowly. People who are on steroids also heal more slowly. The risk of requiring an additional operation for leakage is less than 1%.

r) Hair loss: Hair loss is most common between the third and sixth months. In general, women have their hair re-grow between the sixth and ninth months. Male pattern hair loss is more difficult to predict. It can be frustrating for some women early on, most find it to be not an issue after approximately nine months.

s) Peptic Ulcer: Ulcers in the GI tract are unusual after gastric bypass surgery. The most common place for ulceration is in the small intestines right after the hook-up to the small stomach pouch. Ulcers can occur in the duodenum and defunctionalized stomach as well. Ulcers are more common if patients smoke or take anti-inflammatory medication.

t) Kidney stones: This is an unusual complication following gastric bypass surgery and is more common after some malabsorptive operations. It is important to remember that hydration is very important and may be difficult following stomach surgery and dehydration can cause kidney stones.

u) Blood transfusion with possible reaction: Although blood transfusion is unusual, it may be necessary due to hemorrhage as noted above. Transfusions carry risks that will be described individually if a transfusion is necessary.

v) Staple line obstruction: This complication can occur because of scarring or the staples lines were placed too close together. This is often synonymous with stricture or stenosis listed below.

w) Complications from anesthesia: Complications can occur with anesthesia especially in morbidly obese individuals suffering with sleep apnea syndrome. Complications can occur with any individual, however, and those will be discussed individually by the anesthesiologist.

x) Strictures or stenosis: This occurs primarily at the site where the stomach is attached to the small intestine. It can occur where the small intestine is sewn to itself. Strictures generally require balloon dilation after an endoscopy. The risk of this is generally less than 5%.

y) Possible emotional disorders, including depression: This is quite self-explanatory. Because depression is a possibility, we think a psychological evaluation pre-operatively is very important. Most people do not exhibit critical signs of depression but certainly there can be some let down or “buyer’s remorse” in the early post operative time period. These feelings are generally felt within the first four to six weeks.

z) Novel Complications The possibility that other complications unknown at this time may develop in the future. Though our group has been doing gastric bypass operations since the mid 1980’s, there maybe “new” complications arise that we have not seen before. We think the likelihood is small that something significant will show-up after all these years of study, but it might.

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