Bariatric Surgery for the Treatment of Obesity and Metabolic Disease

Thomas Magnuson MD

Associate Professor of Surgery

Johns Hopkins UniversitySchool of Medicine (tmagnus@jhmi.edu)

JHI Partners Forum 10/2/2012

Disclosure

Nothing to disclose

OBESITY SURGERYOVERVIEW

• Indications for surgery and patient selection

• Current surgical procedures to treat obesity

• Outcomes of surgery: Benefits and risks

• “Metabolic surgery” and impact on diabetes and cardiometabolic risk

Why are we talking about Obesity Surgery today?

1) Rapid rise in prevalence of obesity

2) Recognition of Obesity as a Disease

3) Better operations for Obesity and public/physician awareness

4) Increased focus on improvement/ resolution of metabolic disease

Treatment of Obesity

• Diet & Exercise

• Medications

• Behavioral modification

• Surgical management

Explosion in Bariatric Surgery

Over 200,000 procedures in the U.S. in 2010

Purpose of Bariatric Surgery

• To alleviate or eliminate obesity related medical diseases

• It is not cosmetic surgery and patients may still be overweight after plateau in weight loss postop

Bariatric Surgery Patient Selection

(Based On The 1991 NIH Guidelines)

• BMI > 40; or > 35 with obesity related morbidity• Previous failed attempts at supervised weight

reduction• Realistic expectations; no recent substance abuse• Age limits (18 to 70 yrs old in most programs) • Supportive family/friends• Lifelong commitment to dietary change and follow-

up• Pre-op evaluation by dietician and psychologist

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Obesity Surgery Patient Selection

Additional Considerations

• Adolescents (? informed consent, compliance)• Age > 70yo (higher risk, less medical

benefit, ? Improved quality of life)• “End stage obesity” (severe CHF, home oxygen, non-

ambulatory, BMI>100)• Bridge to other procedures (transplantation; joint

replacement)• Patients post-transplant (liver; kidney)• Lower BMI patients (30-35) with diabetes/htn

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Obesity Surgery

Pre-Operative Evaluation

• Insurance approval (most require 6 month dietary program/counseling within previous 2 years)

• Mandatory Dietary and Psych evaluation/counseling• Cardiac/pulmonary “clearance” if significant history• Sleep apnea testing/treatment if high risk• In select patients- EGD, UGI, IVC filter• Stop smoking and estrogen products (BCP’s) prior to

surgery (high risk for VTE)• Most Bariatric Surgery is performed at “Centers of

Excellence” certified by the ACS and ASMBS

OBESITY SURGERY

OPERATIONS FOR MORBID OBESITY

RESTRICTIVE OPERATIONS

Adjustable Gastric Banding (ABG)Vertical Sleeve Gastrectomy (VSG)Gastric Bypass (GBP) (also malabsorptive)

MALABSORPTIVE OPERATIONS

Gastric Bypass (GBP)Duodenal Switch-biliopancreatic diversion (DS-BPD)

Roux-en-Y Gastric Bypass

• Small gastric pouch (20-30 ml) (remainder of stomach left in)

• ~100 cm of small bowel bypassed creating nutrient malabsorption

Laparoscopic Gastric Bypass

Gastric Bypass

• Durable weight loss: 60 to 70% excess wt loss at 2 yrs

• Proven reduction of obesity related medical problems

• Risk of death low if done by experienced team (<0.5%)

• Most common operation in US with the most follow-up data

• Marginal Ulcer• Stomal stenosis• Anemia• Calcium deficiency• Nutrition/vitamin defic.• Difficult to reverse

PROS CONS

Laparoscopic Gastric Band

• Laparoscopic procedure that is less invasive than gastric bypass

• Adjustable, depending on desired wt. loss

• Weight loss less than gastric bypass (40% excess wt. loss at 1yr post-op)

Adjustable Gastric Band

• Reversible • Least invasive• Lowest risk of Death• No malabsorption• Adjustable• 40 to 50 % excess

weight loss at 2 years

• Foreign body / erosion• Esophageal dilation• GERD• Breakage/slippage• Failure to lose weight• Slower weight loss• 30-50% reoperation

rate/removal long term

PROS CONS

Laparoscopic Vertical Sleeve Gastrectomy

Vertical Sleeve Gastrectomy

Laparoscopic Vertical Sleeve Gastrectomy

• Does not involve intestinal rearrangement• Restrictive only; 50-60% excess weight loss• May be used as a first step operation in high

risk patients to induce weight loss before performing duodenal switch or gastric bypass

• Currently considered for weight loss in lower BMI morbidly obese patients who do not want an adjustable band or a malabsorptive operation

Duodenal Switch

• Partial stomach resection

• All of the bowel bypassed except 150-200 cm of distal small bowel

• Primarily malabsorptive: risk of malnutrition, vitamin deficiency, diarrhea

Duodenal Switch w/ BPD

• Best wt loss (80% excess weight)

• Best resolution of metabolic disease

• Pylorus preserved• Less restriction than

GBP

• Malabsorption • Anemia• Calcium deficieincy• 10 % may need revision• Diarrhea/malodorous stools• Protein malnutrition• ? Liver disease

PROS CONS

Summary of Obesity Surgery

• Gastric bypass (60-70% of all procedures)

• Laparoscopic adjustable gastric band (LAGB) (20-30%)

• Lap Sleeve Gastrectomy (15-25%)

• Duodenal Switch w/ biliopancreatic diversion (5%)

The Johns Hopkins Center for Bariatric Surgery Over 3,000 bariatric procedures since 1997

Age = 41 yo (18 - 74 yrs)Female = 77 %Pre-Op weight = 349 lbs (210 - 740 lbs)Pre-Op Body Mass Index (BMI) = 55.3 (39 - 101)Hospital stay (median) = 2 days (lap=2; open=3)

Pre-Op obesity related disease:• Osteoarthritis = 83 %• Hypertension = 47 %• GERD = 40 %• Diabetes = 27 %• Sleep Apnea (requiring CPAP) = 22 %

Analysis of 1000 gastric bypass procedures:

Obesity Surgery At Johns Hopkins

Weight Loss Excess body wt. loss

12 months =120 lbs 61% 24 months = 134 lbs 67% 36 months = 133 lbs 66% 48 months = 133 lbs. 62% 60 months = 128 lbs. 64%Impact on Medical Disease (by 1 year post-op) Hypertension 73% resolution Diabetes 75% resolution GERD 91% resolution Sleep Apnea 93 % resolution

0 6 12 18 24 30 36 42 48200

225

250

275

300

325

350

WEIGHT LOSS

MONTHS POST-OP

PO

UN

DS

OBESITY SURGERY AT JHBMC

POST-OP COMPLICATIONS(1000 gastric bypass pts.)

Mortality = 0.2 %

Morbidity = 13 %

Wound infection = 6.5 % Pulmonary embolus = 0.9 % Reoperation (< 30 days) = 1.2 % Decubitus ulcers = 0.6 % Anastamotic leak = 0.2 % Bowel obstruction = 0.6 % Readmission = 8 %

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OBESITY SURGERY Evidence based analysis

Is bariatric surgery effective?

• Buchwald 2004 (meta-analysis): Resolution of

% excess wt loss DM HTN Gastric Band 49% 48% 43% Gastric Bypass 61% 83% 67% DS/BPD 70% 98% 83%

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OBESITY SURGERY Evidence based analysis

Is bariatric surgery effective?

• Buchwald 2004 (meta-analysis): Resolution of

% excess wt loss DM HTN Gastric Band 49% 48% 43% Gastric Bypass 61% 83% 67% DS/BPD 70% 98% 83%

• Swedish Obese Subjects Study (SOS) 2007 Longitudinal matched-control cohort study; over 10 yr f/u of 2,010 pts.

- Sustained weight loss in the surgical cohort with reductions in diabetes, dyslipidemia, and HTN compared to matched controls

Mean % Weight Change over 15 Years Swedish Obesity Study

Sjostrom: NEJM 2007;357:741-52

Control

Bands

VBG’s

RYGB30%

Ann Intern Med. 2009;150(2):94-103.

Diabetes Remission after Bariatric surgery

N Engl J Med. 2012.

• Compared the efficacy of three treatments for patients with T2DM and BMI between 27-42 kg/m2:

1.Intensive Medical Therapy*

2.Intensive Medical Therapy* + Laparoscopic Sleeve Gastrectomy

3.Intensive Medical Therapy* + Gastric Bypass

• Primary Endpoint: Proportion of patients with a glycated hemoglobin level of 6.0% or less at 12 months after treatment.

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

12%

42%

37%

Patients at Glycemic Control, 12 months

Med therapy GBP Sleeve

N Engl J Med. 2012

Medication Utilization and Annual Health Care Costs in Patients With Type 2 Diabetes Mellitus Before and After Bariatric Surgery

Makary, et alArchives of Surgery, 2010

• Large multistate insurance claims dataset

• Jan 2002 – Dec 2005

• 2235 patients with diabetes undergoing bariatric surgery

• at least 1 year pre-op and post-op follow up

Results

Diabetes resolution: 1669 (74.7%) of 2235 pts at 6 months 1489 (80.6%) of 1847 pts at 12 months 906 (84.5%) of 1072 pts at 2 years

Prompt Reduction in Use of Medications for Comorbid Conditions After Bariatric Surgery Segal et al, Obesity Surgery, 2009

-6025 pts. undergoing bariatric surgery

-Early post-op reductionin HTN, DM, and lipid-lowering medications

Effect of Surgery on Long-term Mortality Compared to

Non-Operated Controls

Study Procedure F/U Mortality

Reduction

MacDonald,1997 RYGB 9 yrs 88%

Flum, 2004 RYGB 4.4yrs 33%

Christou, 2004 RYGB 5 yrs 89%

Sowemimo, 2007 RYGB 4.4 yrs 50%

O’brien, 2006 LAGB 12 yrs 73%

Adams, 2007 RYGB 8.4 yrs 40%

Sjostrom (SOS), 2007 VBG/RYGB 14 yrs 31%

“Metabolic Surgery”

Future directions:• Patient selection based more on metabolic

disease as opposed to weight (? BMI of 30-35 or lower)

• Better understanding of metabolic and hormonal effects of surgery

• Development of less invasive procedures or drugs which achieve the desired physiologic/metabolic effects

Weight Loss Procedures in Development

Gastric balloonGastric/vagus n. pacing

Endoluminal Surgery

-Endoscopically placed plastic “sleeve” allowing nutrients to avoid contact with duodenal mucosa -Designed to achieve diabetes resolution by altering GI hormone production and islet cell stimulation

EndoBarrier

OBESITY SURGERY Summary

-Bariatric surgery is relatively safe with an expected mortality of <0.5% and morbidity of 10-15%

-Surgery results in sustained weight loss and favorably impacts obesity related medical disease and reduces long term mortality

-Further clinical trials are needed to help determine which operation is best for which patient

The End