It is impossible to discuss all the complications that can occur following any surgery. Our goal is to discuss the most important ones and the most common ones.

Morbid Obesity, Older age, Number of serious medical problems directly increase the risks following ay surgery.

Death: In the United States one out of 200 people having obesity surgery die. In contrast there is a reported excess of 300,000 deaths per year in the morbid obese population who are left untreated by surgical or conventional methods of weight loss. This is about 6-12 deaths per 200. Statistically, morbidly obese individuals will die 10 - 15 years earlier than normal weight persons.

Surgical Problems:

Perforation of the stomach/intestine:  Perforation of the stomach or the bowel may occur during the procedure. This would be repaired immediately. However, in some cases the perforation does not occur for several hours or days. Treatment would depend on the condition of the patient at that time and other specific details about the perforation. Generally this would require a second operation. This may or may not be performed using the laparoscopic approach.

Spleen injury requiring removal: The spleen is a friable organ and lies very close to the upper part of the stomach. Sometimes the spleen is very tightly attached to the part of the stomach being operated on and could be injured with surgical instruments or simply by pulling on it during manipulation of the stomach. Once the spleen is injured it may bleed severely and may necessitate its removal. This, in some cases may require conversion to open procedure.

Liver injury:  The liver lies over the upper part of the stomach and may be injured during the procedure. Most often this does not require any intervention and heals by itself. Rarely conversion to open procedure may be necessary to stop the bleeding and repair the damage.

Other internal organ injury:  Other internal organs may be injured with the surgical instruments or manipulation during the procedure. Any damage would be repaired immediately and most often this can be accomplished without conversion to open approach.

Pancreatitis: This is a rare but serious complication of any abdominal surgery in the vicinity of the pancreas. This would prolong the hospital stay but does not usually require any surgical procedures to treat.

Anastomotic leak: Leakage of the anastomosis can happen with any surgery on the intestines and the stomach. There are several reasons this may occur, which include poor healing, blood supply defects, diabetes and vascular disease. However, no obvious reason has been found in many patients. Treatment depends on patient’s condition, type and extent of leak and other factors. It may be possible to treat the patient with antibiotics and support without surgery, but most of the time re-operation using the open approach becomes necessary. Rarely the anastomotic leak surfaces via the drain and may result in a fistula.
Esophageal injury:  In rare cases esophageal injury may result from instruments used during the laparoscopic approach to perform the anastomosis. Usually this is a minor injury and does not need any further treatment.

Myocardial Infarction (Heart Attack):  May result in permanent heart damage or death. This is a risk with any major surgery.
Congestive Heart Failure: Patients with pre existing heart disease, especially on medications for heart failure are at risk. A heart attack after surgery may also result in this complication

Heart Arrhythmias: Irregular heartbeat may occur during anesthesia or after the surgery.
Stroke: A rare complication following surgery and more common in patients with pre- existing vascular disease.

Atelectasis: This condition is a partial collapse of a part of the lung caused by lack of motion of the chest wall. Normally, your lung is filled with tiny air spaces that remain open allowing air to fill the lung and expand. Lack of motion and weight of the chest wall can allow these tiny pockets to collapse or fill with fluid resulting in your body not receiving the oxygen it needs to recover and heal itself. If left untreated, atelectasis can cause a more serious complication, known as pneumonia. The best treatment is to prevent this from happening by performing deep breathing and lung exercises. We teach you these techniques before surgery and encourage you to do them repeatedly, after the operation. We also have special treatments to help you and your lungs recover if atelectasis should occur.
 
Pneumonia:  Pneumonia is an infection in the lungs. After surgery it can be especially serious because the infecting organisms usually will come from the gastrointestinal (GI) tract. These types of organisms can be very destructive. The risk of pneumonia can be minimized with the use of various anesthetic techniques and respiratory treatments. We also recommend that patients stop smoking at least 30 days prior to their surgery to help prevent this complication from occurring.

Deep Vein Thrombosis and Pulmonary Embolism:  This problem affects the lungs and the heart but it usually starts in the legs with the formation of blood clots. Although these can occur at any time and are more likely in overweight patients, they are especially likely at the time of and soon after surgery. People who have an operation don't like to move around or exercise their legs. Because of this blood becomes stagnant and may form clots in the leg veins. If a clot breaks off and floats through the veins to the lungs it is called a pulmonary embolism. The blood clot blocks the arteries in the lungs and can cause a part of the lung to lose its circulation and die - a pulmonary infarction. If the circulation to a large part of the lung is affected the heart is placed under a great deal of strain and it may fail suddenly. This can be fatal. We want to prevent a pulmonary embolism from occurring by thinning the blood with heparin making it less likely to clot and by prescribing stockings to compress the legs and keep the blood flowing faster through the veins. We try to get the patients up to walk as soon as possible.

Urinary Tract Infection: Urine flow is altered after surgery and patients may have trouble straining down to void. Use of a tube, or catheter, may in rare cases can lead to infection of the bladder. Usually such an infection can be readily eradicated with antibiotic treatment without any additional hospital stay.

Wound Infection:  A wound infection is a type of abscess and is treated by drainage. Morbidly obese persons have a very deep layer of fat under the skin, which predisposes to wound infection.

Abscess:  An abscess is a collection of infected fluid or pus which occurs somewhere in the body. After an abdominal operation, a pocket of fluid may develop and if any bacteria are present, an infection or abscess may occur. The treatment of any abscess is to drain away the infected fluid and kill the bacteria with antibiotics. We want to prevent abscesses by trying to avoid any collections of fluid or blood in the abdomen at the time of surgery. We may place a drain to help remove fluid collection after surgery. If an un-drained abscess develops, we have specialists called interventional radiologists, who often can achieve drainage and resolve the problem without needing another operation to drain it.

Sepsis:  An uncontrolled leak or perforation or an abscess that is not drained will sometimes cause severe infection in the body termed as Sepsis. This condition is rare but is serious and requires intensive care, antibiotics and may require ventilation depending on the clinical condition of the patient. Other complications including death may follow but fortunately this situation is very rare.

Heparin Effect:  We use heparin to prevent blood clotting and pulmonary embolism. At the same time, if blood does not clot at all bleeding will occur when surgery is performed. We work at finding a middle ground, but because the sensitivity of different individuals may vary, delayed bleeding may occur after surgery in some persons. We observe closely for this and can stop the heparin if bleeding gets to be a bigger risk.

Hemorrhage: When surgery is performed blood vessels must be cut. We do this by tying them with a piece of thread, called a ligature, or by using a device called an electrocautery unit, which coagulates the blood and the end of the blood vessel. Sometimes a blood vessel may escape and then begin to bleed again several hours later. This can cause a hemorrhage, either inside the abdomen, inside the stomach and intestines or at the skin level. Bleeding can also occur internally from the staple lines and anastomosis we create. Hemorrhage must be stopped. We have several strategies for this, but in some cases a return to the operating room may be needed. This is a rare event. Blood transfusion may become necessary.

Transfusions: When blood loss occurs it may cause the pulse and blood pressure to become unstable. A blood transfusion may be needed. The blood bank has very high quality standards and the blood is quite safe, but there is still a possibility of getting hepatitis and a very small risk of receiving the AIDS virus (about 1 in 500,000) from a transfusion. Donating your own blood and having it saved for your surgery - a procedure called autologous donation can reduce these risks. There are added costs for having your own blood saved for your surgery (about $150 per pint). The risk of needing a blood transfusion during and following surgery is relatively low. When patients decline to receive blood or blood products for religious reasons, we will honor a commitment to avoid transfusion on your instructions after you sign a special consent.

After any abdominal operation, scars called adhesions can form in the abdomen. They look like strands of latex or sometimes like a piece of fibrous cord. Adhesions can snag a piece of bowel and wrap itself around the bowel closing it up tight, causing blockage so food and fluid can no longer pass. Sometimes, even many years after surgery, a bowel obstruction may result from adhesions. An obstruction as a result of adhesions must be corrected before the bowel loses its blood supply and dies. Usually an emergency operation is necessary. Occasionally, a bowel obstruction due to adhesions can occur within a few days after surgery. In this case, the adhesions are generally much softer and often come apart on their own. Bowel obstruction may be due to adhesions or due to an internal hernia.

When the surgeon fastens bowel to bowel, or bowel to stomach, the connection is called an anastornosis. An anastomotic leak will occur if a tight seal does not form causing leakage of fluid from within the bowel. Fluid from the GI tract, containing bacteria may leak out into the abdomen where it doesn't belong. This can cause a serious infection accompanied by swelling, a rapid pulse rate, and sometimes the formation of an abscess. This is always a very serious complication and its diagnosis and treatment are made more difficult by severe obesity. Conventional wisdom indicates that an immediate operation is required to seal the leak and drain away the infection. Sometimes an Interventional Radiologist can place a special drain at the abscess site without need for surgery and the potential for spreading of infection throughout the rest of the abdomen. Anastamotic leak always causes increase in hospitalization and results in increased discomfort from the drain. Rarely, despite treatment infection may continue and result in sepsis with it’s associated complications. We check for leaks at the end of the procedure with an endoscopy and also the next day with an x-ray study. This is to rule out any technical issues for the leak. However leak is an issue of healing and therefore presents most often between 4th day till the 21st day.

In Gastric Bypass surgery the stomach is connected to the bowel leaving an opening about 1/2 inch in diameter. This is done deliberately in order to slow the flow of food out of the small stomach pouch and into the small intestine. All healing occurs by scar formation and scars have a tendency to contract. This may cause the opening between stomach and bowel to become too small so that food cannot pass through into the small intestine. This causes repeated vomiting, and must be corrected. This may occur in up to 10% of cases and many surgeons continue to be troubled by this complication. The treatment is quite simple and can be corrected with an outpatient endoscopy. Occasionally gastric ulcers may occur at the outlet and cause the narrowing. This usually heals by medical treatment but rarely re-operation may be required.

Development of Gallbladder Disease:

The purpose of the gallbladder is to store bile, which acts as a detergent to help in the digestion of fats. When a fatty meal is eaten bile makes it possible to dissolve and absorb the fat. Following surgery you will be required to drastically reduce your consumption of fatty foods. Since the gallbladder is less likely to use the stored bile, it may develop gallstones and surgical intervention will be necessary to have it removed. As many as 10-25% of patients having weight loss surgery may develop symptoms of gallbladder disease within three years following their surgery.

 Acute Kidney Failure: Very occasionally sudden kidney failure may result secondary to blood loss, dehydration, IV contrast dye or infections and sepsis. This is a rare event.
Liver Failure - Hepatitis, which may cause cirrhosis. Continued consumption of alcohol use following gastric bypass surgery may be damaging to the liver. Alcohol consumption should not exceed 2 small cocktails in a week period. Intoxication occurs quickly due to alcohol entering the small intestine shortly after ingestion and is readily absorbed by the liver.

Chronic Nutritional Problems:

Nutritional problems are quite rare after the Gastric Bypass and are quite readily avoided by use of the proper vitamin and mineral supplements and by eating a healthy diet. One of our most important objectives during our long follow-up is teaching food values and the content of a healthy eating regimen. A remarkable effect of the Gastric Bypass is the progressive change in attitudes toward eating. Patients begin to eat to live - they no longer live to eat.

Protein Deficiency:  Protein is the primary component our muscles, organs, heart, and brain are made of. Our bodies require a constant supply of protein building materials to repair and replace tissues that become worn out or damaged. The Gastric Bypass reduces the capacity of the stomach to a very small volume so protein-containing foods must be carefully eaten with each meal to be sure that the body gets enough to maintain itself. If the first half of each meal is taken as protein-containing foods, deficiency is very unlikely to occur.  You need to maintain 60-70 gm protein intake daily.

Vitamin Deficiency: Conventional nutritional teaching has been that vitamins are contained in adequate amounts in a well-balanced diet and supplements should not be required, provided that one eats a well-balanced diet. After weight-control surgery, the diet initially is much less and does not supply complete nutrition. In order to have any chance of getting enough vitamins, a high potency multivitamin supplement must be taken daily. We think its safest to do this for the rest of your life after this type of surgery. In addition, we have seen a few patients develop deficiency of Vitamin B-12 even when taking a multi-vitamin supplement. B-12 is absorbed in the stomach and duodenum, which are largely bypassed with this surgery. Simple use of a sub-lingual (under the tongue) tablet of B-12 once a week maintains very adequate vitamin levels and prevents deficiency. Vitamin B-12 deficiency can develop without warning and becomes very dangerous to ones health and well-being.

Mineral Deficiency: We recommend a multivitamin preparation containing mineral supplements in generous amounts. We also recommend daily use of calcium. Many patients, particularly women, will require a special iron supplement to maintain adequate iron stores to prevent anemia.

Miscellaneous:

There are several complications that are not listed in this manual. In fact it is impossible to discuss all possible complications because anything may happen and one complication may lead to another. Some of the others are listed below. Discuss any specific concerns you have with your surgeon.
            Electrolyte abnormalities
            Low white blood cell count
            Anemia
            Low blood sugars
            Nesidioblastosis (rare)
            SMA syndrome
            Neuropathies that may be permanent
            Ulcers on the stomach or pouch
            Internal hernias
            Psychosocial Problems:
            Post-operative Depression
            Dysfunctional social problems
            Unrelenting nausea and vomiting

Side-effects occur with any operation. Although they are less serious than complications, they may be permanent and may require a change in lifestyle to avoid continuing discomfort.

Nausea and Vomiting: After gastric restriction, if one gets a full feeling and continues to eat, chances are that an episode of vomiting will result. Most patients have this happen several times and quickly learn to follow instructions to eat slowly, chew food well, and avoid that last bite when fullness occurs. Typically with the gastric bypass, a profound feeling of satisfaction follows the fullness within a few minutes and makes further eating a matter of indifference. During the first few days to weeks, another kind of nausea may follow the gastric bypass. This results from delayed function of the Y-limb and spontaneously resolves with time.

Food Intolerance: The inability to eat certain foods

Red Meats: After the gastric bypass red meats are not well tolerated and may cause vomiting. This is purely a mechanical effect - your stomach cannot tell steak from chicken, except that steak is much harder to break down and more difficult for it to fit through the small stomach outlet. If the outlet gets plugged, vomiting will result. We advise patients to avoid red meats until their stomach is functioning very well, usually after at least 4-6 months following surgery.

Dumping: Refined sugars and candy consist of many small molecules, which tend to draw fluid into the intestine. After the gastric bypass a condition called "dumping syndrome" may occur. This happens when sugar is taken on an empty stomach, passes rapidly through the stomach into the intestine, and draws a large amount of fluid into the bowel. The physiology is complicated, but the result is a condition much like shock: one turns ghostly pale, breaks out into a profuse sweat, feels butterflies in the stomach, a rapid pulse, and a feeling of prostration. Nausea and vomiting, cramps and diarrhea may follow. Most people who have this reaction never try to sneak another candy bar. We believe that this occurrence is not a bad effect when you're trying to lose weight. Negative reinforcement can go a long way in teaching you to pay attention to what’s best for your body and health. The problem of dumping is avoided by avoiding sweets, candies, and fruit juices on an empty stomach. Certain dressings, barbecue sauce, and mayonnaise may also cause problems and need to be avoided.

Milk and Milk Sugar: To digest milk sugar (lactose), our bodies need an enzyme called lactase, which is often in short supply in the lower small intestine. After gastric bypass, milk and milk products may not be fully digested. Farther downstream bacteria will start to ferment with these milk sugars. This causes gas, cramps, and diarrhea. Milk can be treated to make it more tolerable, however it's probably best to avoid it. Many prepared foods (those that come in a box, or Frozen entrees) contain milk sugar as an additive. It is important to learn to be a label-reader or to avoid packaged foods and especially junk food.

Changed Bowel Habits:  After restrictive surgery, the amount of food consumed is greatly reduced and the quantity of roughage consumed may be much smaller. Correspondingly, the amount of bowel movements will be diminished, causing less frequent bowel activity and constipation. Diarrhea, bloating, cramping, malodorous stool or flatus may occur following gastric bypass surgery. Prescribed medications and dietary changes can be used to help alleviate discomfort.

Transient Hair Loss:  During the phase of rapid weight loss, calorie intake is much less than the body needs and protein intake is marginal. The body is in a panic state similar to what would happen during a period of starvation. One of the side effects, in some persons, is inactivation of 30 - 40% (rather than the usual 10%) of hair follicles, causing noticeable amounts of hair to fall out. This is a transient effect and resolves when nutrition and weight stabilize. We advise patients to avoid hair treatments and permanents and be sure of adequate protein intake. Sometimes a zinc supplement will help and Minoxidil (a drug to prevent and reverse hair loss) may be tried.

Loss of Muscle Mass:  When the body is in a panic state and trying to combat starvation, it hoards its precious fat until any other usable fuel has been burned. Practically, the body will prefer to bum muscle mass before consuming its precious fat (don't ask us why - we didn't write the rules). If muscle is not regularly used for exercise, like every day, it will be consumed to meet energy needs. Loss of muscle mass is preventable. It is very important during active weight loss following surgery (or even when on a diet), to exercise vigorously every day. We recommend at least 20 minutes a day of aerobic activity. Devote particular attention to upper body strength. Many persons find that after a few weeks or months of regular daily exercise that they actually begin to enjoy it and start to work out even more. Fairly vigorous exercise, for more than 30 minutes a day, can greatly enhance fat-burning and hasten weight loss. It also builds a healthy and beautiful body.

Weight Gain or failure to loss satisfactory weight: The outcome of surgery depends largely upon the patient’s response in terms of healing and complications, motivation to follow instructions after surgery as well as your own body response to the whole process. Inevitably the body adjusts itself to the surgery and the weight loss slows down and reaches a plateau. In some patients this happens earlier than others. However, in spite of all efforts, sometimes a patient simply does not respond to the operation in the manner acceptable to the patient or surgeon. If it becomes necessary, surgery most often can be reversed, although this usually is at greater risk than the initial surgery itself. 

Pregnancy:  Pregnancy can happen following weight loss surgery, therefore, requiring special warning. Many severely overweight women are infertile because the fatty tissue soaks up the normal hormones and makes some of its own as well. This completely confuses the ovaries and uterus and causes a lack of ovulation. As weight loss occurs, this situation may change quickly. It is important to avoid conception during the phase of weight loss - about 18 months after surgery. You will not be able to provide adequate nutrition to both yourself and a fetus during pregnancy. This requires special attention to contraception, even by those who think that it can't happen. "Natural" infertility may not last - in fact; it can go away in one night! Birth control pills may not be absorbed well and so even when you are taking them there is a risk of contraception failure. Talk to your physician about other options such as Nuvaring or a patch.