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What Are the Health Complications of Weight Loss Surgery?

Jeremy Korman';

By Jeremy Korman

Posted on August 4th, 2020 in Weight Loss

While bariatric surgery is one of the safest groups of procedures, with a mortality rate of only 0.1% and with over 250,000 overweight and obese people undergoing it annually, it still entails a series of postoperative complications, which can ensue immediately afterward or over the years.

However, to ensure that the potential health complications which can arise following weight loss surgery do not endanger the life of the patient, they will be permanently monitored by a team of medical professionals after the procedure. Your surgeon will also inform you with regard to the health complications which can occur following the bariatric procedure you are planning to undergo. Nevertheless, health complications are quite rare among individuals who undergo bariatric surgery, particularly if they follow the recovery instruction given by their surgeon and regularly come to the hospital for follow-up appointments. The following are the most common health complications for the bariatric procedures we perform at Cedars Sinai Marina del Rey Hospital.

Early Health Complications of Weight Loss Surgery

Although bariatric procedures such as adjustable gastric band and gastric bypass can be very effective for gradual and safe weight loss, they imply a series of complications that can arise several days after the procedure. Nonetheless, if any of these complications ensue, the medical team which supervises you will promptly attend to the health issues you developed, as some of these complications may be fatal if not timely and adequately treated.


When a leak occurs, the mortality rate increases to 15%, whereas the morbidity rate increases to 61%. Thereby, this health complication is very serious and requires immediate medical attention. Anastomotic leaks, which occur when there is a discharge of luminal fluid from a surgical join, can prolong hospital stay and may result in gastroenteric and gastrobronchial fistulae, complications which usually take months to resolve. Patients who have persistent tachycardia, fever, dyspnea, and abdominal pain are very likely to experience a leak. The average time the person experiences these symptoms is 3 days following surgery. It is not uncommon for patients who have leaks to be sent to the emergency room.


Stenosis involves the abnormal narrowing of a blood vessel or, in the case of bariatric surgery, of a tubular organ. When stenosis occurs, people who have just undergone weight loss surgery will experience the sensation of stuck food and the urge to regurgitate. These symptoms closely resemble those of esophageal dysphagia and the patient will be unable to pass food or liquid beyond the gastric sleeve, which can lead to protein-calorie malnutrition and nutrient deficiencies. People who experience stenosis as a consequence of bariatric surgery need to undergo a neurologic examination, biochemical testing for malnutrition, and nutrition replacement. The most common weight loss procedure after which patients are susceptible to develop stenosis is Roux-en-Y gastric bypass. However, their stenosis will be easy to treat if diagnosed early and there will be no need for additional surgery. The incidence of stenosis in this group of patients is 8% to 19%.


Severe postoperative bleeding occurs in up to 11% of people who undergo Roux-en-Y gastric bypass and sleeve gastrectomy. Nonetheless, the bleeding will stop in 85% of cases without surgical intervention. Patients with dysmetabolic syndrome X have more chances of experiencing bleeding following their bariatric procedure. The treatment of bleeding usually entails establishing adequate venous access, crystalloid resuscitation, blood transfusions, serial hematocrits, hemodynamic monitoring, and correction of any coagulopathies. A skillful endoscopist can easily detect anastomosis, a connection made between adjacent blood vessels or parts of the intestine, in the early postoperative period, and subsequently perform therapeutic endoluminal interventions such as clips or epinephrine injections as a first-line treatment.

Venous Thromboembolism

While this health complication is rare, when it occurs, it is very serious and can even be fatal if treatment is not immediately administered. A pulmonary embolism is the primary cause of death among people who undergo bariatric surgery, usually developing 3 weeks after the procedure. The patients who have a high risk of experiencing venous thromboembolism include those undergoing revision bariatric surgery or open weight loss procedures, those whose surgery takes more than 4 hours to perform, those with hypercoagulable states and those with obesity hypoventilation syndrome. A CT angiogram will be able to detect a pulmonary embolism immediately. The treatment for pulmonary embolism implies systemic anticoagulation and catheter-directed lytic therapy.

Adjustable Gastric Band Complications

The majority of adjustable gastric band surgery complications stem from the device itself, as it can slip or break. Late health complications include band erosion, acute obstruction, ischemia, and megaesophagus or pseudoachalasia, which are significantly more serious. The incidence of patients who undergo adjustable gastric band surgery and subsequently have to go through a second procedure is nearly 25%. Band slippage, which occurs when one side of the stomach slips through the whole of the band and results in a larger upper portion of the stomach, is one of the most common health complications of adjustable gastric band surgery. Up to 8% of patients experience it. However, fundoplication around the band and the pars flaccida technique may reduce the risk of band slippage.

While it may sound like a medical emergency, band erosion does not actually pose a risk to the life of the patient. It is worthy of note that this health complication occurs in 0.31% to 1.96% of people who undergo adjustable gastric band surgery. The symptoms of band erosion are usually vague, including upper abdominal pain, loss of food restriction, new onset of reflux, back pain, and infection of the subcutaneous band port. X-rays and CT scans are employed to diagnose band erosion, as they are very effective for this purpose. Treatment options primarily depend on the degree of band erosion and may entail laparoscopic removal of the band or removing the band endoscopically by cutting the tubing and extracting the band through the mouth.

Another health complication that can stem from adjustable gastric band surgery is megaesophagus or pseudoachalasia, which usually does not require treatment. It entails the motility of the esophagus and loss of tone, which can result in diffuse dilation, vomiting, and regurgitation. The dilation of the esophagus mostly occurs as a consequence of chronic overeating following the bariatric procedure. Megaesophagus treatment may involve the emptying of the band as a treatment in some cases.

The Health Complications of Gastric Bypass

Gastric bypass may also lead to the occurrence of postoperative complications, as the procedure irreversibly alters the anatomy of the digestive tract.

Some of the most common health complications of gastric bypass are the following:

  • gallstone disease: people who undergo gastric bypass have a higher risk of developing gallstone disease than the general population, as alterations in enterohepatic circulation, hormonal changes associated with weight loss and increased biliary stasis may contribute to it
  • marginal ulceration: less than 5% of people who undergo Roux-en-Y gastric bypass experience this health complication, which entails the development of mucosal erosion at the gastrojejunal anastomosis
  • perforation: spontaneous perforation may occur in 1% to 2% of patients who underwent gastric bypass and thereby, this is a less common health complication, but can have serious consequences
  • small bowel obstruction: people who had gastric bypass may experience small bowel obstruction as a result of internal hernias or postoperative adhesions
  • internal hernia: this is one of the health complications of the gastric bypass which is the most difficult to detect, as well as one of the most serious problems

Undergo Bariatric Surgery at Cedars-Sinai Marina del Rey Hospital

Whether you are pondering undergoing bariatric surgery or have already decided to have a weight loss procedure, please contact our hospital for additional information and we will gladly answer all your questions and address all your concerns. At Cedars-Sinai Marina del Rey Hospital, we have one of the best bariatric surgery departments and our bariatric surgeons have over 25 years of experience. After a thorough examination, they will be able to recommend the most effective and safest weight loss procedure for you. Following the surgery, our medical team will permanently monitor your health in order to avoid any postoperative complications. In the rare case that you experience a health complication, our medical specialists will promptly treat it so that it will not endanger your life.