Bariatric and Metabolic Surgery Program

Bariatric and Metabolic Surgery Program

The Bariatric and Metabolic Surgery Program at Massachusetts General Hospital offers a full spectrum of safe and effective surgical procedures for obesity, weight disorders and metabolic disease.
Refer a patient online Learn more about the Weight Center

Call to refer a patient or request a new patient appointment: 617-726-0373


Surgeons in the Massachusetts General Hospital Bariatric and Metabolic Surgery Program are members of the Mass General Weight Center, a multidisciplinary team of obesity experts that provide individualized consultation and innovative obesity treatment, including state-of-the-art medical and surgical programs.

Bariatric & Metabolic Surgery Experts

Mass General surgeons perform a high volume of weight loss surgeries and achieve excellent outcomes. Each is a board-certified, Harvard Medical School-affiliated surgeon who specializes in treating patients with complex medical disorders related to obesity as well as weight disorders and metabolic disease. According to the Commonwealth of Massachusetts, 11% of our patients undergoing weight loss surgery had an illness before their surgery categorized as major or extreme, compared with a statewide figure of 2%. This specialization requires advanced training and a highly focused clinical practice.

Mass General is a designated Blue Distinction Center for Bariatric Surgery from Blue Cross Blue Shield of Massachusetts. Blue Distinction Centers are healthcare facilities recognized for their expertise in delivering specialty care.

High Marks in Surgical Quality 

The Mass General Department of Surgery and Codman Center for Clinical Effectiveness have been recognized for meritorious outcomes in surgical patient care from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). Hospitals achieve this distinction based on composite quality score in the outcomes in mortality and complications such as cardiac, respiratory, unplanned intubation, ventilator greater than 48 hours, renal failure, surgical site infections and urinary tract infections for all surgery cases.

This recognition reflects the outstanding performance of the hospital’s surgical teams in providing patient care at many levels. This distinction goes to only approximately 10 percent of the 680 participating hospitals entering data into NSQIP.

View the most recent data

Our Procedures

Mass General is an accredited member of the American College of Bariatric Surgery Center Network. We offer the following surgical options for appropriate patients seeking weight loss:

  • Revisional surgery: This is an option for patients suffering from complications of previous weight loss surgery
  • Roux-en-Y gastric bypass: Staples are used to divide the stomach into a small pouch and larger remnant. This procedure may be conducted laparoscopically (a minimally invasive approach that requires only small incisions) or as standard open surgery
  • Vertical sleeve gastrectomy: An alternative to gastric banding, this leading-edge procedure involves removal of three quarters of the stomach

In addition, the Mass General Body Contouring Program performs body-contouring procedures to remove excess skin and reshape the body to its desired proportions following weight loss surgery.

Becoming a Patient

To become a candidate for surgery, you will need to be referred to the Weight Center by your primary care physician. Once referred, you will attend a Weight Center orientation and then receive a multidisciplinary consultation. If surgery is recommended, you will meet with one of our surgeons to discuss our surgical treatment programs in greater detail.
In addition to our surgeons, your multidisciplinary team may include:

  • Endocrinologists
  • Gastroenterologists
  • Obesity medicine specialists
  • Psychologists
  • Registered dieticians

Our Surgeons

  • Gee, Denise W., MD


    Accepting New Patients

    Clinical Interests
    • Laparoscopic / Minimally invasive surgery
    • Foregut (GERD, achalasia, paraesophageal hernias, GISTs)
    • Colon (diverticulosis/diverticulitis, tumors)
    • Hernias (inguinal, ventral, incisional)
    • Solid Organ (gallbladder, spleen, adrenals)
    • Bariatrics
    Board Certifications
    • Surgery, American Board of Surgery
    • Boston: Massachusetts General Hospital
    • Danvers: Mass General/North Shore Center for Outpatient Care
  • Hutter, Matthew M., MD


    Accepting New Patients

    Clinical Interests
    • Laparoscopic / Minimally invasive surgery
    • Colon surgery
    • Stomach surgery
    • Gallbladder surgery
    • Hernia surgery
    • Gastrointestinal surgery
    • Bariatric surgery
    • Diverticulitis
    Board Certifications
    • Surgery, American Board of Surgery
    • Boston: Massachusetts General Hospital
    • Boston: Weight Center, MGH
  • Meireles, Ozanan R., MD


    Accepting New Patients

    Clinical Interests
    • Bariatric and Metabolic Surgery
    • POEM - Endoscopic Esophageal Myotomy (Achalasia)
    • Gastroesophageal reflux disease (GERD)
    • Paraesophageal hernias
    • Laparoscopic / Minimally invasive surgery
    • Upper GI endoscopy and endoluminal procedures
    • Natural orifice translumenal endoscopic surgery (NOTES)
    • Hernias
    Board Certifications
    • Surgery, American Board of Surgery
    • Boston: Surgery Department
    • Boston: Weight Center, MGH
  • Witkowski, Elan R., MD


    Accepting New Patients

    Clinical Interests
    • Bariatric and Metabolic Surgery
    • General and gastrointestinal surgery
    • Paraesophageal hernias
    • Hernia surgery
    • Abdominal wall reconstruction
    • Gastroesophageal reflux disease (GERD)
    • Achalasia
    • Gallbladder and biliary tract disease
    • Gastric (stomach) cancer
    • Robotic surgery
    • Minimally invasive surgery
    Board Certifications
    • Surgery, American Board of Surgery
    • Boston: Surgery Department
    • Boston: Weight Center, MGH

About this Program

A Multidisciplinary Team Approach to Care

Before and after your surgery, we work with your entire treatment team to design an individualized treatment plan that promotes long-term weight loss. Experts are available for counseling on nutrition, exercise and behavior modification along with medical management of related diseases.
We also offer pediatric evaluation and treatments for obesity in conjunction with MassGeneral Hospital for Children.

What to Expect

Evaluation Your surgical evaluation begins with a Weight Center orientation. This is an one-hour lecture led by one of our obesity experts who will explain obesity, the weight center, and both medical and surgical treatments that are available.  You will then receive a call to schedule an initial evaluation by a multidisciplinary team including a psychologist, dietician and in some cases, an internist specializing in obesity medicine.

Before Surgery

Pre-surgery Nutrition Program

Your insurance company and/or your Weight Center team may require you to attend a three to six month pre-surgery program consisting of nutrition and, in some cases, psychology visits.
The Weight Center has developed a pre-surgery program that helps you prepare for surgery both physically and psychologically. Nutrition education is centered on achieving pre-surgery weight loss to reduce surgical risks, understanding a healthy lifestyle and teaching healthy eating habits. The psychological component of this program is focused on providing you the tools and techniques for achieving pre-weight loss surgery goals. This program fulfills the pre-operative requirements of several insurance companies and may be recommended by our team or required before enrolling in our surgical management program.

Pre-surgery “Shrink the Liver” Diet

Studies show that rapid weight loss before bariatric surgery results in significant decrease in the size of the liver. This size decrease makes the surgery technically less difficult and faster, reducing postoperative complications. All patients who are scheduled for weight loss surgery are encouraged to lose some weight prior to surgery, and our dietitians have developed a meal replacement diet specifically designed to induce weight loss. You will meet with a dietitian to individualize this weight loss plan.

The Surgical Management Program

Preparing for weight loss surgery is important, and our program is designed to provide you with the information you will need to succeed in losing weight and in avoiding postoperative complications.  You will be required to meet again with your entire team before surgery, as well as attend two group nutrition education classes. During these classes, you will be provided with instructions on your postoperative diet, and how to prepare for surgery.

After Surgery

The Surgical Management Program is designed to prepare you for gastric weight loss surgery and to monitor, guide and support you post-operatively. The six-month post-operative program is divided into two, three-month phases.

The first phase is Postoperative Adjustment. During this time, the Weight Center dietitian educates you about the early postoperative changes, including the diet transition from liquids to solid food. The program includes group  classes for nutrition education, as well as individual psychology and nutrition visits. Your Weight Center psychologist provides support for necessary behavioral changes.

The second phase is Lifestyle Modification, which follows immediately after the Postoperative Adjustment phase. During Lifestyle Modification, the group nutrition sessions focus on the changes in nutrition and exercise that are necessary for long-term weight loss success. These sessions and individual appointments are designed to help you support your commitment to behavior change.


To keep the cost of the Surgical Management Program to a minimum, all medical and surgical visits are billed to the patient’s insurance company. Some components of the program may not be covered by insurance. Learn more about these costs

Patient Outcomes

At Mass General, we believe it's important to provide safe and effective care.  The Department of Surgery tracks many performance measures and compares them to national data. On the following pages, you can view some of these metrics.

Bariatric Surgery Case Volume

Bariatric Surgery Case Volume
See how Mass General’s bariatric surgery volumes compare to national accreditation standards.

Bariatric Surgery Case Volume

Patient Ratings of Bariatric Surgeons
See how Mass General’s bariatric surgery patients rate their doctors.                                      

Laparoscopic Gastric Bypass
3 charts

Laparoscopic Gastric Bypass
Learn more about the benefits and risks of laparoscopic gastric bypass surgery.

Laparoscopic Sleeve Gastrectomy
3 charts

Laparoscopic Sleeve Gastrectomy
Learn more about the benefits and risks of laparoscopic sleeve gastrectomy.

Conditions & Diseases

  • Asthma

    Asthma is a chronic, inflammatory disease in which the airways become sensitive to allergens (any substance that triggers an allergic reaction).

  • Asthma and Children

    Approximately 6.5 million children have been diagnosed with asthma according to the Centers for Disease Control and Prevention (CDC). Asthma is one of the most common, serious, chronic diseases among children, accounting for 14 million absences from school each year.

  • Carotid Artery Disease

    Carotid artery disease, also called carotid artery stenosis, occurs when the carotid arteries, the main blood vessels that carry oxygenated blood to the brain, become narrowed.

  • Coronary Heart Disease

    Coronary heart disease occurs when cholesterol builds up within the walls of the heart’s arteries (coronary arteries), forming what is called plaque.

  • Diabetes

    Type 1 diabetes may also be known by a variety of other names, including the following: insulin-dependent diabetes mellitus (IDDM), juvenile diabetes, brittle diabetes, or sugar diabetes.

  • Gastroesophageal Reflux Disease (GERD) / Heartburn

    Gastroesophageal reflux disease (GERD) is a digestive disorder that is caused by gastric acid flowing from the stomach into the esophagus.

  • Heart Attack

    A heart attack occurs when one or more regions of the heart muscle experience a severe or prolonged lack of oxygen caused by blocked blood flow to the heart muscle.

  • Heart Failure

    Heart failure, also called congestive heart failure, is a condition in which the heart cannot pump enough oxygenated blood to meet the needs of the body's other organs.

  • High Blood Pressure / Hypertension

    Blood pressure, measured with a blood pressure cuff and stethoscope by a nurse or other health care provider, is the force of the blood pushing against the artery walls.

  • Indigestion

    Indigestion, also known as dyspepsia, is a painful or burning feeling in the upper abdomen and is usually accompanied by nausea, bloating or gas, a feeling of fullness, and, sometimes, vomiting.

  • Metabolic Syndrome

    Metabolic syndrome is a condition that includes the presence of a cluster of risk factors specific for cardiovascular disease. Metabolic syndrome significantly raises the risk of developing diabetes, heart disease, and/or stroke.

  • Obesity

    Obesity increases the risk for many diseases, especially heart disease, stroke, cancer, and diabetes.

  • Snoring

    Snoring is the sound that occurs during sleep when flow of air is obstructed in the area where the tongue and upper throat meet the soft palate and uvula.

  • Type 1 Diabetes

    Type 1 diabetes may also be known by a variety of other names, including the following: insulin-dependent diabetes mellitus (IDDM), juvenile diabetes, brittle diabetes, and sugar diabetes.

  • Type 2 Diabetes

    Type 2 diabetes is a metabolic disorder resulting from the body's inability to make enough, or to properly use, insulin.

Clinical Trials


  • Weight Loss Gastric Balloon: Placement

    Weight Loss Gastric Balloon: Placement

    During the procedure, an endoscope with a thin, deflated balloon is inserted through the patient’s mouth and placed into the stomach. The balloon is then filled with sterile saline until it is about the size of a grapefruit, and stays in the stomach for six months. No incisions are made during this nonivasive procedure.

  • Weight Loss Gastric Balloon: Removal

    Weight Loss Gastric Balloon: Removal

    After six months, a nonsurgical procedure, similar to the balloon insertion, is performed to remove the gastric balloon. The balloon is deflated first and then removed.

  • Anesthesia

    General Anesthesia Educational Video

    Learn more about general anesthesia in this educational video.


Contact Us

Division of General and Gastrointestinal Surgery

Wang 46015 Parkman St. Boston, MA 02114
  • Phone: 617-643-7557

Massachusetts General Hospital Weight Center
50 Staniford Street
4th Floor
Boston, MA 02114

Phone: 617-726-4400
Fax: 617-724-6565
Hours: 7:30 am to 6:00 pm, Monday through Friday

Refer a patient online Learn more about the Weight Center

Call to refer a patient or request a new patient appointment: 617-726-0373

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