Bariatric surgery, also known as metabolic surgery or weight-loss surgery, encompasses a range of procedures that alter your digestive system to facilitate weight loss. These surgeries are considered when conventional methods like diet and exercise have proven ineffective, particularly in cases of severe obesity or obesity-related health complications. Bariatric procedures can limit food intake, reduce nutrient absorption, or employ a combination of both approaches.
While bariatric surgery offers significant potential health benefits, it’s crucial to recognize that these are major surgical interventions carrying inherent risks and potential side effects. Furthermore, achieving and sustaining long-term success with bariatric surgery necessitates permanent lifestyle modifications, including dietary changes and consistent physical activity.
Types of Bariatric Surgery Procedures
Several types of bariatric surgery are available, each with its unique approach to weight loss. Understanding the differences between these procedures is essential for making informed decisions.
Roux-en-Y Gastric Bypass
The Roux-en-Y gastric bypass is one of the most frequently performed bariatric surgeries. This procedure is generally irreversible and works through two primary mechanisms. Firstly, it reduces the size of your stomach to a small pouch, roughly the size of a walnut, significantly limiting the amount of food you can consume at one time. Secondly, it alters the digestive pathway by bypassing a portion of the stomach and the upper part of the small intestine, reducing the absorption of calories and fat.
During a Roux-en-Y gastric bypass, the surgeon creates a small stomach pouch by dividing the upper part of the stomach from the rest. This pouch is then connected directly to the middle section of the small intestine (jejunum), bypassing the lower stomach and the first part of the small intestine (duodenum). This rerouting of food reduces both the quantity of food you can eat and the calories your body absorbs.
Sleeve Gastrectomy
Sleeve gastrectomy involves the removal of approximately 80% of the stomach. The remaining portion of the stomach forms a narrow, tube-like “sleeve”. This smaller stomach capacity restricts food intake, leading to weight loss. Additionally, sleeve gastrectomy can reduce the production of ghrelin, a hormone that stimulates appetite, potentially further aiding weight management by decreasing hunger cravings.
A key advantage of sleeve gastrectomy is that it avoids rerouting the intestines, unlike gastric bypass. It is also associated with a shorter hospital stay compared to many other bariatric procedures.
Biliopancreatic Diversion with Duodenal Switch (BPD/DS)
Biliopancreatic diversion with duodenal switch (BPD/DS) is a more complex, two-part surgical procedure, often performed in a single session. The first step is a sleeve gastrectomy, as described above.
The second step, the duodenal switch, involves dividing the small intestine. The end portion of the small intestine (ileum) is connected directly to the duodenum, the first part of the small intestine, near the stomach. The bypassed middle section of the small intestine is reattached further down the ileum, allowing digestive juices (bile and pancreatic juices) to eventually mix with food, but significantly reducing nutrient and calorie absorption.
While BPD/DS is highly effective for weight loss, it carries a greater risk of complications, including malnutrition and vitamin deficiencies, due to the significant reduction in nutrient absorption.
Single-Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy (SADI-S)
Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is another two-step procedure, beginning with a sleeve gastrectomy.
In the second step, the duodenum, just below the newly formed stomach sleeve, is disconnected and attached to a segment of the lower small intestine (ileum). This duodeno-ileal bypass shortens the path of food through the small intestine to approximately 10 feet, compared to the typical 25 feet. This reduction in intestinal length limits the time and surface area available for the body to absorb fat and calories.
The choice of bariatric surgery procedure is highly individualized. Surgeons consider various factors, including body mass index (BMI), eating habits, pre-existing health conditions, previous surgical history, and the specific risks associated with each procedure to determine the most suitable option for each patient.
Why Bariatric Surgery is Considered
Bariatric surgery is primarily performed to help individuals achieve significant weight loss and mitigate the risks associated with severe obesity and related health problems. These weight-related conditions can be life-threatening and significantly impact quality of life. Bariatric surgery may be recommended to address or prevent:
- Certain cancers, including breast, endometrial, and prostate cancer
- Cardiovascular diseases, such as heart disease and stroke
- Hypertension (high blood pressure)
- Hyperlipidemia (high cholesterol levels)
- Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH)
- Obstructive sleep apnea
- Type 2 diabetes
Bariatric surgery is typically considered after non-surgical weight loss attempts, such as diet and exercise modifications, have been unsuccessful in achieving and maintaining clinically significant weight loss.
Who is a Candidate for Bariatric Surgery?
Generally, bariatric surgery may be an option for individuals who meet specific criteria:
- Extreme Obesity: A body mass index (BMI) of 40 or higher.
- Obesity with Comorbidities: A BMI between 35 and 39.9, accompanied by serious weight-related health conditions like type 2 diabetes, hypertension, or severe sleep apnea. In some cases, individuals with a BMI of 30 to 34 and significant weight-related health issues may also qualify for certain types of weight-loss surgery.
However, bariatric surgery is not a universal solution for everyone struggling with excess weight. Candidates must undergo a thorough screening process to determine their suitability for surgery. This assessment evaluates medical history, psychological factors, and commitment to long-term lifestyle changes. Furthermore, individuals must be willing to commit to ongoing follow-up care, including nutritional monitoring, lifestyle adjustments, and management of any medical conditions.
It’s also important to consider the financial aspects of bariatric surgery. The cost can be substantial, and insurance coverage varies. It’s essential to verify insurance policy details or explore options with Medicare or Medicaid to understand coverage for bariatric procedures.
Potential Risks of Bariatric Surgery
As with any major surgical procedure, bariatric surgery involves potential health risks, both in the immediate postoperative period and in the long term.
Short-term risks associated with bariatric surgery can include:
- Excessive bleeding
- Infection
- Adverse reactions to anesthesia
- Blood clot formation
- Pulmonary complications (lung or breathing problems)
- Leakage from the gastrointestinal system
- In rare cases, mortality
Longer-term risks and complications vary depending on the specific type of bariatric surgery performed. These can include:
- Bowel obstruction
- Dumping syndrome (leading to diarrhea, flushing, lightheadedness, nausea, or vomiting)
- Gallstone formation
- Hernias
- Hypoglycemia (low blood sugar)
- Malnutrition and vitamin deficiencies
- Ulcer development
- Vomiting
- Acid reflux
- Need for revisional surgery or procedures
- Rarely, death
Preparing for Bariatric Surgery
If you are deemed a suitable candidate for bariatric surgery, your healthcare team will provide detailed instructions on how to prepare for your specific procedure. This preparation phase may involve:
- Pre-surgical medical evaluations and lab tests
- Dietary restrictions, including limitations on eating and drinking
- Medication adjustments or temporary cessation
- Initiation of a physical activity program
- Smoking cessation if applicable
Furthermore, planning for post-operative recovery is crucial. This may include arranging for support at home during the initial recovery period.
What to Expect During Bariatric Surgery
Bariatric surgery is performed in a hospital setting under general anesthesia, ensuring you are unconscious and pain-free throughout the procedure.
The surgical approach can vary based on individual circumstances, the chosen type of weight-loss surgery, and the surgeon’s and hospital’s practices. Traditionally, some bariatric surgeries were performed using large abdominal incisions (open surgery).
However, minimally invasive laparoscopic techniques are now commonly employed for many types of bariatric surgery. Laparoscopic surgery utilizes a laparoscope, a thin, tube-like instrument equipped with a camera. Inserted through small incisions in the abdomen, the laparoscope allows the surgeon to visualize and operate within the abdominal cavity without the need for large incisions. Laparoscopic surgery often results in faster recovery times and shorter hospital stays, although it may not be suitable for all patients.
Surgery duration typically ranges from several hours. Following surgery, you will be monitored in a recovery room for any immediate complications. The length of hospital stay can vary, potentially lasting a few days, depending on the specific procedure and individual recovery progress.
Alt text: Expert surgical team performing minimally invasive bariatric surgery using laparoscopic techniques in a modern operating room.
Life After Bariatric Surgery
Dietary Progression
Following bariatric surgery, oral intake is typically restricted for the first 1 to 2 days to allow the stomach and digestive system to heal. Subsequently, a carefully structured diet plan is implemented, progressing through stages over several weeks. This dietary progression starts with liquids only, advancing to pureed and very soft foods, and eventually transitioning to regular solid foods. Long-term dietary restrictions and limitations on portion sizes and food choices are essential for sustained weight management and to prevent complications.
Follow-up Care
Regular medical follow-up appointments are crucial, particularly in the initial months after bariatric surgery, to monitor health status, assess weight loss progress, and address any potential complications. These follow-up visits may involve laboratory tests, bloodwork, and various medical examinations.
Expected Results of Bariatric Surgery
Bariatric surgery, including gastric bypass and other procedures, can lead to substantial and long-lasting weight loss. The extent of weight loss varies depending on the type of surgery performed and the individual’s adherence to recommended lifestyle changes. Many individuals can achieve a loss of half or more of their excess weight within the first two years after surgery.
Beyond weight loss, bariatric surgery can significantly improve or resolve numerous health conditions often associated with obesity, such as:
- Heart disease
- Hypertension
- Hyperlipidemia
- Sleep apnea
- Type 2 diabetes
- Nonalcoholic fatty liver disease (NAFLD) and NASH
- Gastroesophageal reflux disease (GERD)
- Osteoarthritis-related joint pain
- Certain skin conditions, including psoriasis and acanthosis nigricans
Furthermore, bariatric surgery can enhance physical function and the ability to perform everyday activities, leading to an improved overall quality of life.
When Weight Loss Surgery May Not Be Effective
While generally successful, bariatric surgery may not always yield the desired outcomes in every individual. In some cases, weight loss may be insufficient, or weight regain may occur over time. If a weight-loss procedure is not effective or ceases to be effective, it’s essential to consult with your healthcare team promptly.
Maintaining all scheduled follow-up appointments is crucial for monitoring progress and addressing any concerns. If you notice a lack of weight loss or experience any complications, seek immediate medical attention. Your healthcare providers can investigate potential reasons for stalled weight loss or complications and recommend appropriate interventions.
Weight regain after bariatric surgery, even when the procedure itself was technically successful, can occur if recommended lifestyle modifications, such as regular physical activity and adherence to a healthy diet, are not consistently followed. Long-term commitment to these lifestyle changes is paramount for maintaining weight loss and maximizing the benefits of bariatric surgery.
Explore Mayo Clinic studies of tests and procedures to help prevent, detect, treat or manage conditions.
Bariatric surgery care at Mayo Clinic
References
- Obesity, surgical management. Clinical overview. Elsevier; 2022. https://www.clinicalkey.com. Accessed June 24, 2023.
- Feldman M, et al., eds. Surgical and endoscopic treatment of obesity. In: Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 11th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed June 24, 2023.
- Bariatric surgery procedures. American Society for Metabolic and Bariatric Surgery. https://asmbs.org/patients/bariatric-surgery-procedures.Accessed June 21, 2023.
- Shetye B, et al. Bariatric surgery, gastrointestinal hormones, and the microbiome: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022. Obesity Pillars. 2022; doi:10.1016/j.obpill.2022.100015.
- Types of weight-loss surgery. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/weight-management/bariatric-surgery/types. Accessed June 21, 2023.
- Bariatric surgery. Endocrine Society. https://www.endocrine.org/patient-engagement/endocrine-library/bariatric-surgery. Accessed June 21, 2023.
- Ami TR. Allscripts EPSi. Mayo Clinic. May 26, 2023.
- Ghanem OM (expert opinion). Mayo Clinic. July 26, 2023.
- Ami TR. Allscripts EPSi. Mayo Clinic. May 26, 2023.
