bariatric surgery in obesity and metabolic disease

Bariatric Surgery in Obesity and

Metabolic DiseaseOlivier Court MD FRCSC

Director, section of Bariatric SurgeryMcGill University Health Center

Disclosure of Conflict of Interest

• no affiliation with the manufacturer of any commercial product or provider of any commercial service discussed in this CME activity.

Outline• Prevalence of Obesity

• Consequences of Obesity

• Treatments for obesityo Non-operativeo Surgical options

• Benefits of Bariatric Surgery

• Mechanisms for metabolic benefits

Weight classification according to BMI

Prevalence of obesity

Prevalence of obesity

Prevalence of obesity

Co-mobidities of obesity

JAMA. 2004 Oct 13;292(14):1724-37

Cost of obesity in Canada

1997 2006

• The total direct cost of obesity in Canada was $1.8 billion

• 2.4% of the total health care expenditures

• The total direct costs of obesity in Canada was $4.0 billion

• 4.1% of the total health care expenditures

CMAJ 1999 Feb 23;160(4):483-8 Obes Rev. 2010 Jan;11(1):31-40

Obesity and mortality

Lancet. 2009 Mar 28;373(9669):1083-96.

Treatments for obesity

Obesity: non-operative management

• Diets• Few patients ever achieve more than 10% weight loss• Over 95% regain all weight lost by 5 years

• Pharmacotherapyo Orlistat (Xenical)

• Inhibits intestinal lipase• Not absorbed – Safe• Expected weight loss: 10%

o Sibutramine (Meridia)• Monoamine reuptake inhibitor – acts centrally to diminish appetite• Average weight loss at 1 year: 10 lbs• Can induce significant hypertension• Taken off market in Canada, still available in US

Obesity: Surgical management

NIH Concensus recommendations

• Patients whose BMI exceeds 40

• Patients with a BMI between 35 and 40 if they also have some severe comorbidities related to obesity:

o NIDDMo Obstructive Sleep Apneao Severe Osteoarthritis

Surgical options

• Restrictive procedures• Laparoscopic Adjustable Gastric Band• Laparoscopic Sleeve Gastrectomy

• Malabsorptive procedures• Laparoscopic Roux-en-Y Gastric Bypass• Laparoscopic Biliopancreatic Diversion with

Duodenal Switch

Laparoscopic Adjustable Gastric

Band• Creation of 30-60cc

pouch• Adjustable pouch

outlet• Easy insertion

• Resultso 2 years – 30-40% EBWo 5 years – 50% EBW

Laparoscopic Adjustable Gastric

Band

• Disadvantages

o Expensiveo Band slipping/erosiono Band/port malfunctiono Unknown durability

Laparoscopic Sleeve Gastrectomy

• Resection of about 75% of stomach

• Few complications

• Resultso No long term datao 1 year - 50% EBWo 3 years - 60% EBW

Laparoscopic Roux-en-Y Gastric Bypass

• Creation of 30-60cc pouch

• Roux limb 100 cm• Bypass stomach,

duodenum and proximal jejunum

• Resultso 1 year – 65-70% EBWo 5 years – 60-70% EBWo 10 years – 60% EBW

Laparoscopic Roux-en-Y Gastric Bypass

• Complications

o Mortality about 0.1%o Anastomotic leak 2-3%o Dumping syndromeo Iron/Calcium/vit B12 deficiencyo Drinkingo Marginal ulceration

Laparoscopic Biliopancreatic Diversion with Duodenal

Switch• Sleeve gastrectomy• Duodeno-jejunal

anastomosis• Roux limb 150cm• Common channel

100cm

• Resultso 1year – 70% EBWo 5 years – 75-80% EBWo 10 years – 80% EBW

Laparoscopic Biliopancreatic Diversion with Duodenal

Switch

• Complications

o Mortality about 0.5%o Anastomotic leak 2-3%o Steatorrheao Ca, Iron, vit A,D,E,K deficiencyo Protein malnutrition 2-3%

Benefits of Bariatric Surgery

JAMA. 2004 Oct 13;292(14):1724-37

Resolution of Comorbidities

(136 studies, 22,904 patients)

Metabolic benefits beyond weight loss

Metabolic benefits beyond weight loss

• 150 patients with BMI 27 – 43 followed for 12 months

• 3 groups:o Intensive medical therapy (n=50): lifestyle counseling, weight mgt,

home glucose monitoring, medications including incretin analogues to reach HbA1c < 6%

o Gastric bypass (n=50)o Sleeve gastrectomy (n=50)

• Primary endpoint: % of pts with HbA1c<6%

• Secondary endpoints: Fasting glucose, fasting insulin, lipids, CRP, HOMA-IR, weight loss

Metabolic benefits beyond weight loss

Metabolic benefits beyond weight loss

Diabetes

Diabetes

Metabolic benefits beyond weight loss

Metabolic benefits beyond weight loss

• 72 patients with BMI>35 with followed for 2 years• 3 groups:

o Medical therapy (n=24)o Gastric bypass (n=24)o Biliopancreatic diversion (n=24)

• Primary endpoint: rate of DM remission (fasting glucose<5.6 and HbA1c<6.5% without medication)

• Secondary endpoints: Average HbA1c, body weight, triglycerides, total and HDL cholesterol

Metabolic benefits beyond weight loss

Resolution of comorbidities

Bariatric Surgery: Impact on Mortality

Study Center Surgery Type Reduction in Risk of Death

McGill University(Canada)

Gastric Bypass 89%

University of Padoa(Italy)

Adjustable Gastric Band 60%

Monash University(Australia)

Adjustable Gastric Band 72%

Gothenberg University(Sweden)

Gastric Bypass, GastroplastyAdjustable Gastric Band

24%

University of Utah(USA)

Gastric Bypass 40%

Average 57%

Study Center Surgery Type Reduction in Risk of Death

McGill University(Canada)

Gastric Bypass 89%

University of Padoa(Italy)

Adjustable Gastric Band 60%

Monash University(Australia)

Adjustable Gastric Band 72%

Gothenberg University(Sweden)

Gastric Bypass, GastroplastyAdjustable Gastric Band

24%

University of Utah(USA)

Gastric Bypass 40%

Average 57%

Cost effectiveness of Bariatric Surgery

Conclusion• Impact of obesity on health care is growing

• Bariatric Surgery results in weight loss, but also in resolution of comorbidities and improvement in mortality

• Mechanisms are still unclear

• Bariatric vs Metabolic Surgery

Mechanisms for metabolic benefits of

Bariatric Surgery

Role of Gut hormones

Mechanisms of action RNYGB AGB VSG

Mechanisms of action RNYGB AGB VSG

Mechanisms of action• Hind Gut vs Fore Gut theories for RNYGB

• However, VSG and RNYGB are similar in their metabolic and hormonal effects

• Both differ from AGB

• Alternate explanation is required