Bariatric Surgery: What the Internist Needs to Know

Richard Stahl, MD, FACS Assistant Professor of Surgery

Medical Director of Bariatric Surgery

Disclosures

None

(sadly)

Objectives

• Describe several myths and facts related to obesity treatment.

• Identify the indications and contraindications for bariatric surgery and the process for approval.

• Describe the current common bariatric surgical procedures, and compare their benefits, risks, and outcomes.

• Describe several potential complications of bariatric surgery.

NEJM 368;5 January 31, 2013

Presumptions Skipping breakfast leads to obesity because people eat more later

Just eating fruits and vegetables will lead to weight loss

Weight cycling (i.e., yo-yo dieting) increases mortality

Snacking inherently leads to weight gain

Myths Increasing activity modestly yields large weight loss over time

Setting unrealistic weight loss goals is detrimental

PE classes lead to weight loss

Sex burns 100 – 300 kcal yielding weight loss

Facts “Heritabiltiy is not destiny”

Diets are effective; simply recommending one is not

Exercise is important for health; very vigorous exercise is required for weight loss

Obesity is a chronic condition; treatment must be also

Bariatric surgery is effective

Degrees of Obesity

NORMAL BMI 18.5 – 24.9

OVERWEIGHT BMI 25 – 29.9

Class I Obesity BMI 30 – 34.9

Class II Obesity BMI 35 – 39.9

Class III Obesity

BMI 40

Impact of BMI on Mortality and Years of Life Lost

Graph represents years of life lost for white men. Fontaine KR, Redden DT, et al. Years of life lost due to obesity. JAMA 2003;289:187. UAB Bariatric Surgery

Indications for Weight Loss Surgery

1. Initial attempt at non-surgical weight loss

2. Bariatric surgery for motivated, appropriate risk patients

3. Multi-disciplinary team management

4. Surgeon and facility with appropriate experience and support

5. Life long follow up

How are we doing?

• 70% of US adults are overweight

• 34% are obese (i.e., BMI ≥30)

• 6% are morbidly obese (BMI ≥40)

18 million people age 20-74 are morbidly obese

About 113,000 cases are done annually*

159 years to operate on all of these * Am J Surg . 2010 September ; 200(3): 378–385

90% feel obesity is a serious chronic medical condition and should be discussed with patients

75% agree even 10% reduction in weight is beneficial

50% would spend more time managing weight issues if

reimbursed and feel comfortable doing so

22% feel long term weight loss management is possible

23% would refer patients for bariatric surgery if patients met criteria

OBESITY RESEARCH Vol. 11 No. 10 October 2003

Pre-certification Requirements Age ≥18 years

BMI 35-40 with co-morbidities

BMI ≥40 regardless of co-morbidities

At least 3 years duration

Acceptable for major elective abdominal surgery

6 month PCP directed diet

www.uabmedicine.org

THE OPERATIONS

Current Topics in Weight Loss Surgery

Nguyen et. al. Ann Surg. 2009 Aug 27

Weight Loss Bypass vs Band

Weight Loss: Bypass vs Sleeve

Remission of Co-Morbidities

Mortality and Morbidity

Bypass Band Sleeve

Mortality 0.5% 0.1% 0.4%

Laparoscopic Appendectomy

Laparoscopic Cholecystectomy

Mortality 0.1% 0.3%

from H. Buchwald, J Am Coll Surg 2005;200:593–604

From Manish M. Tiwari, Surg Endosc. 2010 Oct 7. [Epub ahead of print]

Band Sleeve Bypass

Slippage Leak Leak

Erosion Stricture Stricture

Port / band infection Reflux Ulcer

Leakage Small bowel obstruction / internal hernia

Port dislodgement Vitamin / micronutrient deficiencies: especially iron, calcium, Vitamins B1, B12, and D

Esophageal motility / dilitation

Risks

MECHANISMS

Current Topics in Weight Loss Surgery

How do they work?

Patients eat less!!

Why do they eat less?

Does Size Matter?

Is it Malabsorption?

Is it Malabsorption?

Could it be Better Choices?

Mason EE, et.al. Intl J of Obesity (1981) 5: 457-464

Maybe the patients got really motivated to eat right!

Sleeve gastrectomy rats decreased their consumption of calorie dense foods on their own volition

Long Term Care / Considerations

• Vitamins / supplements

• Pills, tablets, crushed?

• Altered medication absorption?

• Alcohol

• Hypoglycemia

• Anemia

• Wernicke's encephalopathy

• Abdominal pain

• Failure / Recidivism

• Bariatric surgery is the most effective treatment of morbid obesity

• It is indicated in appropriate risk patients with BMI ≥ 40 (or 35 with co-morbidities

• Gastric bypass and sleeve gastrectomy yield better results than bands

• Mortality and morbidity risk is commensurate with other common GI operations