Bariatric Surgery

Roberto C. Mirasol, MD, FPCP, FPSEMObesity and Weight Management CenterSt. Luke’s Medical Center

Bariatric Surgery

• Indications1. BMI >40 kg/m2 or

BMI 35–39.9 kg/m2 and life-threatening cardiopulmonary disease, severe diabetes, orlifestyle impairment

2. Failure to achieve adequate weight loss with nonsurgical treatment • Contraindications

1. History of noncompliance with medical care2. Certain psychiatric illnesses: personality disorder, uncontrolled

depression, suicidal ideation, substance abuse3. Unlikely to survive surgery

NIH Consensus Development Panel. Ann Intern Med 1991;115:956.

CLINICAL PRACTICE RECOMMENDATIONS, 2009ADA

• Bariatric surgery should be considered for

adults with BMI 35 kg/m2 and type 2 diabetes, especially if the diabetes is difficult to control with lifestyle and pharmacologic therapy. (B)

• Patients with type 2 diabetes who have undergone bariatric surgery need life-long lifestyle support and medical monitoring. (E)

Bariatric Surgery Stats 1995 the number of bariatric surgeries performed

was well over 20000 2003 - 103,000 2004 - 144,000 Average age of patient – 30 years oldLength of Hospital Stay – 3.9 daysBariatric surgeons – increased by 500%Complication rate – 10%Deaths <1%

CDC, 2006

Current Bariatric Surgical ProceduresClassification

Gastric restriction

Primarily restrictive and partially malabsorptive

Primarily malabsorptive and partially restrictive

Procedure

• Adjustable Gastric Banding

• Roux-en-Y Gastric Bypass

Biliopancreatic diversion with duodenal switch

Biliopancreatic diversion

Distal gastric bypass

Gastric Bypass ProcedureA small (10–30 mL) gastric pouch is anastomosed to a Roux limb of jejunum. Increasing the length of the Roux limb increases malabsorption and weight loss.

Long-term Effect of Gastric Bypass Surgery on Body Weight

Poiries et al. Ann Surg 1995;222:339.

BMI (kg/m2): 50 34 35 35

We

igh

t Los

s(%

of E

xces

s W

eig

ht)

Years After Surgery

0

20

40

60

80

1000 2 4 6 8 10 12 14

Randomized, Controlled Trial Comparing Open With Laparoscopic

Gastric Bypass• Both procedures had

– Similar weight loss– Similar incidence of anastomotic leaks– Equivalent costs

• Laparoscopic procedure had– Less wound complications (infection and hernia)– Increased late anastomotic strictures – Less blood loss– Shorter hospital stay – Faster recovery– Faster improvement in quality-of-life

Nguyen et al. Ann Surg 2001;234:279.

Weight Loss With Gastric Bypass Procedure vs. Vertical Banded GastroplastyD

ecre

ase

in E

xces

s W

eigh

t (%

)

Gastric bypass

Vertical banded gastroplasty

6 3612 18 24 300

Time (months)

Sugerman et al. Ann Surg 1987;205:613.

10

90

70

50

30

Laparoscopic Adjustable Gastric Banding

Silicone band placed around upper stomach to create a small pouch. Outlet diameter can be changed by infusing or withdrawing saline from port.

Gastric BandConnection tubing

Access port (reservoir)

LapBandTM

American Society for Metabolic and Bariatric Surgery, www.asbs.org

LAP BAND

-30

-25

-20

-15

-10

-5

0

Obrien et al. Ann Intern Med. 2006;144:625-33

Wei

ght L

oss,

%

Baseline

Surgical

Nonsurgical

*(VLCD, behavioral modification, and pharmacotherapy)

6 mo 12 mo 18 mo 24 mo

LLaparoscopic aparoscopic AAdjustable djustable GGastric astric BBanding anding Produces Produces Greater Weight Loss than CGreater Weight Loss than Comprehensive omprehensive MMedical edical TTherapyherapy** in in PPatients with Class I Obesity (BMI 30-35 kg/matients with Class I Obesity (BMI 30-35 kg/m22))

Sleeve gastrectomy with rerouting of small intestine through “nutrient limb” and “biliopancreatic limb.”

Digestion and absorption are limited to 100 cm “common channel” of terminal ileum.

Causes marked weight loss, but can lead to significant nutritional deficiencies.

Biliopancreatic Diversion With Biliopancreatic Diversion With Duodenal SwitchDuodenal Switch

Marceau P. et al. World J Surg 1998;22:947-54.

ApproximateLoss of Excess

Procedure Weight (%)

Laparoscopic gastric banding 45–65

Gastric bypass procedure 55–65

Biliopancreatic diversion 60–75

with duodenal switch

Effect of Different Bariatric Surgical Procedures on Weight Loss

Klein et al. Gastroenterology. 2002;123:882-932

Relationship Between Rate of Weight Loss and Gallstone Formation

Weinsier et al. Am J Med 1995;98:115.

Inci

denc

e of

Gal

lsto

ne F

orm

atio

n(%

sub

ject

s/w

k)

1

3

2

00 0.5 1 1.5 2 2.5

Rate of Weight Loss (kg/wk)

Data reported from individual studies

Complications of Bariatric SurgeryAll procedures: • Atelectasis and pneumonia • Deep vein thrombosis• Pulmonary embolism• Wound infection• Gastrointestinal bleeding• Gallstones• Failure to lose weight• Intractable vomiting/kwashiorkor (B1)• Mortality (0.1%–2%)Gastric bypass:• Anastomotic leak with peritonitis• Stomal stenosis • Marginal ulcers • Staple line disruption• Nutrient deficiencies (iron, calcium, folic

acid, vitamin B12)• Dumping syndrome• Small bowel obstruction

– Internal hernia– Adhesions

Gastric banding procedure:• Band slippage • Band erosion • Esophageal dilatation• Band or port infections• Port disconnection• Port displacementBiliopancreatic diversion:• Anastomotic leak with peritonitis • Protein-calorie malnutrition• Calcium, iron, folic acid, fat soluble

vitamin (A,D,E,K) deficiencies• Dehydration• Steatorrhea• Small bowel obstruction

– Internal hernia– Adhesions

D Flum et al. J Am Coll Surg 199:543, 2004

Thi

rty

Day

Mor

talit

yRelationship Between Surgical Experience and Relationship Between Surgical Experience and Perioperative Mortality in Gastric Bypass Surgery Perioperative Mortality in Gastric Bypass Surgery

7%

6%

5%

4%

3%

2%

1%

0%0 50 100 150 200 250 300 350 400 450 500 550 600 650

Chronological case order per surgeon

125 case lifetime bariatric 125 case lifetime bariatric surgery experiencesurgery experience

0

25

50

75

100

Patents with Type 2 Diabetes

Patients with IGT

Pa

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nts

wit

h N

orm

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asti

ng

B

loo

d G

luc

os

e a

nd

Hb

A1

c A

fte

r S

urg

ery

(%)

Gastric Bypass Surgery Improves Glycemic Control in Impaired Glucose Tolerance or Type 2 Diabetes

Pories et al. Ann Surg 1995;222:339.

4.7

18.5

0.0

3.6

0.0

4.0

8.0

12.0

16.0

20.0

2 8Follow-up After Surgery (y)

Inci

denc

e of

Typ

e 2

Dia

bete

s(%

Pat

ient

s) Control Bariatric surgery

Prevention of Type 2 Diabetes at 8 Years After Bariatric Surgery (94% Restrictive)

Sjostrom et al. Hypertension 2000;36:20.

Control Surgery Initial BMI (kg/m2) 41 5 41 4Weight change at year 8: 1 11% -16 12%

0

20

40

60

80

100

2 yr 10 yr 2 yr 10 yr 2 yr 10 yr

Effect of Bariatric Surgery on Obesity-related Metabolic Complications

Sjöström: N Engl J Med 2004;351:2683.

Rat

io o

f Rec

over

y (%

of s

ubje

cts)

21

72

Diabetes Hypertension Hypertriglyceridemia

13

36

21

34

11

19 22

62

24

46

Control Surgery

0

1

2

3

Steatosis

His

tolo

gy

sco

re

(Bru

nt

et

al.

sy

ste

m) Before GBS

1 Yr after GBS

Inflammation Fibrosis

Effect of Gastric Bypass Surgery-induced Effect of Gastric Bypass Surgery-induced Weight Loss on Liver HistologyWeight Loss on Liver Histology

Klein S. et al. Gastroenterology 130:1564, 2006

0

1

2

3

4

5

6

7

Control Bariatric Surgery

Long-term Survival: Canada

Rel. Risk = 0.11 (.04-.27)

89% reduction in risk ofdeath over 5 years

Christou et al. Ann Surg 2004;240:416-424

% M

ort

alit

y

Major Obesity-related Comorbidities That Have Been Improved by Bariatric Surgery

• Type 2 diabetes• Hypertension• Obstructive sleep apnea• Obesity hypoventilation• GERD• NALD, NASH• Pseudotumor cerebri• Depression

• Dyslipidemias• Coronary artery disease• Cardiac dysfunction• Venous stasis disease• Polycystic ovary syndrome• Infertility• Cancers• Degenerative joint disease• Quality of life

GLP-1 and GIP Are the Two Major Incretins

GLP-1 GIP• Produced by L cells mainly located

in the distal gut (ileum and colon) • Stimulates glucose-dependent

insulin release

• Produced by K cells in the proximal gut (duodenum)

• Stimulates glucose-dependent insulin release

Other effects• Suppresses hepatic glucose output

by inhibiting glucagon secretion in a glucose-dependent manner

• Inhibition of gastric emptying; reduction of food intake and body weight

• Enhances beta-cell proliferation and survival in animal models and isolated human islets

• Minimal effects on gastric emptying; no significant effects on satiety or body weight

• Potentially enhances beta-cell proliferation and survival in islet cell lines

GLP-1=glucagon-like peptide-1; GIP=glucose-dependent insulinotropic polypeptide.

Drucker DJ. Diabetes Care. 2003;26:2929–2940; Ahrén B. Curr Diab Rep. 2003;3:365–372; Drucker DJ. Gastroenterology. 2002;122:531–544; Farilla L et al. Endocrinology. 2003;144:5149–5158; Trümper A et al. Mol Endocrinol. 2001;15:1559–1570; Trümper A et al. J Endocrinol. 2002;174:233–246; Wideman RD et al. Horm Metab Res. 2004;36:782–786.

Nonincretin Gut Peptides

• Peptide YY (PYY)– Secreted by the L cells of the distal intestine– Present in 2 molecular forms: PYY(1-36) and PYY

(3-36), a cleavage product– PYY increases satiety and delays gastric emptying

through neuropeptide Y-receptor subtypes in the central and peripheral nervous system

– IV PYY(3-36) increases satiety and decreases food intake in humans

Nonincretin Gut Peptides

• GHRELIN– Secreted by gastric fundus and proximal small intestine

and acts on the hypothalamus to regulate appetite– Inhibits insulin secretion by a paracrine mechanism– Systemic ghrelin levels increase before a meal and

decrease afterward– Ghrelin stimulates appetite and food intake and

suppresses energy expenditure and fat catabolism– Inversely proportional to body weight – Weight loss increases ghrelin levels suggests that ghrelin

affects long term regulation of body weight

PROPOSED MECHANISMS FOR IMPROVED GLYCEMIC CONTROL AFTER BARIATRIC SURGERY

Effects of Decreased Caloric Intake on Fasting Glycemia

• Decreased caloric intake affects glucose metabolism

• Rate of diabetes remission are not the same – Complete remission within days of intestinal

bypass procedures (Porries, 1995)– Takes months to occur in LAGB (Dixon, 2008)

RUBINO EXPERIMENTS

• Goto- Kakizaki Rats- non obese animal model for diabetes

DJB (duodenal-jejunal bypass) – less fasting and postprandial hyperglycemia than control

Weight loss by caloric restriction – glycemic control did not improve

HINDGUT HYPOTHESIS (LOWER INTESTINAL HYPOTHESIS)

• Intestinal rearrangement speeds the delivery of nutrients to the distal intestines

• Causes exaggerated GLP-1 and PYY levels and improves glucose tolerance and insulin secretion

Cummings, et al, 2007

FOREGUT EXCLUSION THEORY (UPPER INTESTINAL HYPOTHESIS)

Bypassing gut prevents the secretion of a “putative signal” that promotes insulin resistance and Type 2 DM.

• Stomach sparing DJB vs Gastrojejunostomy (leaves nutrient flow in the proximal intestine intact)

• Bypass of proximal gut prevents secretion “Anti-incretin factor” or “decretin”

• May be implicated in the pathogenesis of diabetes

Gut Peptide Response to Different Bariatric Surgical Procedures*

HORMONE Cell Type (Location)

Effect on Insulin Secretion

BPD RYGB LAGB

Ghrelin X/A cells Stomach

Decrease Increase Increase/Decrease

Increase/No Change

GIP K cells duodenum

Increase Decrease Decrease No change

GLP-1 L cellsDistal ileum

Increase Increase Increase No change

Peptide YY L cellsDistal ileum

Decrease Increase Increase No change

*Folli, 2007

BARIATRIC SURGERY IN ST LUKE’S

PATIENT PROFILE*MALE FEMALE TOTAL

Number (%) 18 (36%) 32 (64%) 50

Age group

14-18 1 (6%) 1(3%) 2 (4%)

19-59 15 (83%) 30 (94%) 45 (90%)

>60 2 (11%) 1 (3%) 3 (6%)

BMI (mean)

14-18 57 46.8 51.9

19-59 47.07 46.15 46.5

>60 39.45 39 39.3

Obesity Types

Obese (30-40) 7 (39%) 10 (31%) 17 (34%)

Morbidly obese (40-50)

4 (22%) 12 (38%) 16 (32%)

Super obese 7(39) 10(21%) 17 (34%)

*Dineros, Obesity Surgery, 2007

Weight Reduction in ALL Patients*Postoperative Period

Initial Weight(kg+ SD)

Weight Loss(kg + SD)

% Excess Weight Loss

BMI(kg / m2)

Start 126.7+ 25.4 0 0.00 48.0+ 11.7

1 month 115.9 + 19.4 10.7 + 6.4 8.50% 43.2 + 9.2

3 months 113.2 + 21.4 13.4 + 6.4* 10.60% 42.3 + 9.9

6 months 93.5 + 24.7 33.1+ 10.9* 26.10% 33.7 + 7.1

9 months 91.4 + 20.8 35.3 +10.4* 27.90% 32.4 + 8.7

12 months 68.6+ 10.8 38.3 +11.9* 31.00% 27.5 + 3.1

Dineros, Obesity Surgery, 2007

COMPLICATIONS

• Early Complications• Wound infection 2/50• Pneumonia 1/50• Dehydration 1/50• Gastritis 1/50• Leakage 1/50

COMPLICATIONS

• Late Complications• Band Slippage 2/20 (10%)• Stomal Stenosis 1/20 (5%)• Ventral Hernia 1/5 (20%)

STARTING WEIGHT: 307 lbs; BMI 49.44END WEIGHT: 156 lbs; BMI 25.16

STARTING WEIGHT:

516 lbs; BMI 83.10

END WEIGHT:

258 lbs; BMI 37.01

100 kg (220 lb)

76 kg (168 lb)

BYPASS on Non- obese

• 2 mildly overweight• Duodenal bypass lowered fasting insulin,

fasting glucose, and HgbA1c within 1 month after surgery

Diabetes Surgery Summit,

Rome, 2007