Bariatric Surgery

Anwar Ali Jammah

PGY5

Case

• BR a 32y old women with BMI of 39.2 kg/m2. • Obese science childhood and get very little

exercise. • She has been unable to lose weight despite

multiple diets, and regains weight rapidly after each diet.

• Her medical history includes Type 2 Dm on OHA.

World Health Organ Tech Rep Ser 2000

Diet, and lifestyle

• Who should receive counseling on diet, lifestyle, and goals for weight loss. – All patients who are overweight (BMI ≥ 27 kg/m2) or

obese (BMI ≥30 kg/m2).

– Patients with a BMI of > 25 kg/m2 who have an increased waist circumference (>40 inches/102 cm in men or >35 inches/88 cm in women) or with comorbidities.

Life style modificationBody composition changes in obese adults following diet, exercise or diet plus exercise intervention

VariableDietExerciseDiet and exercise

Weight lost, kg10.7 ± 0.52.9 ± 0.411.0 ± 0.6

% of body fat decrease6.0 ± 1.03.5 ± 0.57.3 ± 0.8

Weight loss maintained at one year6.6 ± 0.56.1 ± 2.18.6 ± 0.8

Tremblay, A, Despres, J, Maheux, J, et al, Med Sci Sports Exerc 1991;

• Well designed, intensive lifestyle intervention typically achieve a weight loss of 8% to 10% and patient usually regain weight when the intervention ands.

Case

• BR Wt. decreased by 6% and then eventually stabilized.

• Her internist added pharmacotherapy to her weight loss regimen.

Net effect of drug trials for anti-obesity drugs

DrugDuration of studiesWeight loss kg (mean and 95% CI)

FDA approval

Orlistat52 wk-2.75 (-3.32 to -2.20)Yes

Sibutramine52 wk-4.45 (-5.29 to -3.62)Yes

Phentermine2 to 24-3.6 (-6.0 to -0.6)Yes

Diethylpropion6 to 52-3.0 (-11.5 to 1.6)Yes

Li Z, Maglione M, Tu W, et al. Ann Intern Med 2005

• BR’ weight decreased and her comorbidities improved and she reduced her OHA dosage over 6 months of therapy. Her weight maintained for 2 months i.e. no further reduction.

case

• After 8 months she discontinued the drug therapy and did not follow the life style recommendation as before.

• Her weight went up again and started on insulin to control the blood sugar.

• BMI now is 41.3 kg/m2.

• She states that her obesity hurts he quality of life both socially and at work.

Bariatric Surgery

• Indications:– Have a BMI >40.– Adults with a BMI >35 who have serious

comorbidities:• Diabetes.• Sleep apnea.• Obesity-related cardiomyopathy.• Severe joint disease.

– Be well-informed and motivated. – Have acceptable risk for surgery. – Have failed previous non-surgical weight loss.

National Institutes of Health (NIH) Consensus

Bariatric Surgery

• Contraindications:– Untreated major depression or psychosis. – Binge eating disorders. – Current drug and alcohol abuse. – Severe cardiac disease with prohibitive anesthetic

risks. – Severe coagulopathy. – Inability to comply with nutritional requirements

including life-long vitamin replacement.

• Bariatric surgery in advanced (above 65) or very young age (under 18) is controversial.

National Institutes of Health (NIH) Consensus

AACE/TOS/ASMBS Bariatric Surgery Guidelines, Endocr Pract. 2008;14(No. 3)

Comorbidities

– Hypertension.– Impaired glucose tolerance.– Diabetes mellitus.– Dyslipidemia.– Sleep apnea.

AACE/TOS/ASMBS Bariatric Surgery Guidelines, Endocr Pract. 2008;14(No. 3)

Types of bariatric procedures

Restrictive

Vertical banded gastroplasty

Laparoscopic adjustable gastric band

Sleeve gastrectomy

Malabsorptive

Jejunoileal bypass

Biliopancreatic diversion

Biliopancreatic diversion with duodenal switch

Combination of restrictive and malabsorptive

Roux-en-Y gastric bypass

 

Vertical banded gastroplastyR

Laparoscopic adjustable gastric band LAGB.R                            

Jejunoileal bypassM

Biliopancreatic diversion with duodenal switchM

Roux-en-Y gastric bypass (RYGB)R & M

Biliopancreatic diversionM

Atul K Madan 2007

Technology Assessment Unitof McGill University HealthCentre, 2004

• enough evidence to indicate that LAGB is effective procedure with adequate safety record of up to 5 years

• while there is insufficient evidence to determine whether LAGB is a superior procedure to LRYGB, there are incidences where it is safer

Australian Safety and Efficacy Register of New Interventional Procedures- Surgical (ASERNIP-S), 2002

• comparative studies suggest that RYGB produces more weight loss than LAGB and VBG at least up to 2 years; after 2 years, advantage only seen between RYGB and VBG• all 3 procedures resulted in considerable weight-loss up to 4 years post-surgery• LAGB found to be safer in terms of short-term mortality rates

Alberta Heritage Foundationfor Medical Research(AHFMR), 2000

• concluded that RYGB was gold standard to treat morbid obesity

• early attempts at LAGB show high rate of complications and re-operations

• well-designed studies with at least 5-years follow-up will determine if LAGB will become more mainstream

• LAGB should become accepted option

• Procedure-related Complications– Bleeding – Infection – Incisional hernia – Anastomotic, gastric pouch or duodenal leaks – Anastomotic or stomal stenosis – Perforation of a major blood vessel or organ

http://www.obesityonline.org/slides/slide01.cfm?tk=45&pg=2

AACE/TOS/ASMBS Bariatric Surgery Guidelines, Endocr Pract. 2008;14(No. 3)

complications • Dumping syndrome :

– Cramping – Nausea – Diarrhea – Lightheadedness – Palpitations – Sweating

• Gallstones which can occur in anyone who loses weight rapidly.

• Ulcers at the margin of the anastomosis between the stomach and the pouch, may cause IDA.

• Drug absorption rates may change:– reduction in intestinal surface area. – changes in gastric pH.

G. Darby Pope Surg Innov 2006; 13; 265

• Weight lost:– 60%(95% CI 58-64%) of excess Wt. loss, varying according to the specific the

procedure.• Gastric banding < Gastricbypass < Gastroplasty < Biliopancreatic diversion or

duodenal switch.

• 30-day mortality was: – 0.1 % for purely restrictive procedures. – 0.5 % for gastric bypass.– 1.1 % for biliopancreatic diversion or duodenal switch.

• Diabetes: – completely resolved in 77 % and resolved or improved in 86 %.

• Hyperlipidemia:– improved in 70 % or more of patients.

• Hypertension:– resolved in 62 % and resolved or improved in 79 %.

• Obstructive sleep apnea:– resolved in 86 % and resolved or improved in 84 %.

Ghrelin

• Stimulates appetite and induces a positive energy balance that can lead to weight gain.

• Induces adiposity that is sustained as long as the levels is elevated.

• Activates neuropeptide Y (NPY) and agouti-related protein-producing neurons in the arcuate nucleus of the hypothalamus.

• Stimulates gastric contraction and enhances stomach emptying.

• Affect bone metabolism. osteoblasts have been shown to express the ghrelin. Ghrelin stimulates both osteoblast cell proliferation and differentiation.

Peptide YY

• Peptide YY(3–36) a gut-derived hormone.

• Reduces food intake over the short term.

• Obese persons have been found to have lower baseline PYY levels than lean persons.

• PYY deficiency may has a role in the pathogenesis of obesity.

OBESITY February 2006

Chan JL; Obesity (Silver Spring). 2006.

Korner J. JClin Endocrinol Metab 2005.

Alvarez Bartolome Obes Surg. 2002

This post-prandial increase in PYY is not reported after an adjustable gastric band.

series of 12 patients undergoing the vertical banded gastroplasty reported an increase in fasting and postprandial PYY after surgery.

Copyright ©2005 The Endocrine Society

Korner, J. et al. J Clin Endocrinol Metab 2005;90:359-365

FIG. 2. Circulating concentrations of PYY in response to a liquid test meal (A); peak levels of PYY (B); AUC of PYY at 90, 120, and 180 min post meal (C), determined in lean, RYGBP,

and BMI-matched groups

J Clin Endocrinol Metab, May 2006, 91(5):1735–1740 1737

Effect of weight loss by gastric bypass surgery versus hypocaloric diet on glucose and incretin levels in patients with type 2 diabetes J Clin Endocrin Metab

DIABETES CARE, VOLUME 30, NUMBER 7, JULY 2007

Dixon JAMA. 2008

Adjustable Gastric Banding and Conventional Therapy for Type 2 Diabetes. A Randomized Controlled Trial Published in JAMA Jan 23, 2008

Unblinded randomized controlled trial conducted from December 2002 through December 2006 in Australia.

• 60 patients (BMI >30 and <40) recently diagnosed (<2 years) type 2 DM.

• 2-years follow-up.

• Remission of type 2 diabetes was achieved by 22 (73%) in the surgical group and 4 (13%) in the conventional-therapy group.

• Surgical and conventional-therapy groups lost a mean (SD) of 20.7% (8.6%) and 1.7% (5.2%) of weight, respectively, at 2 years (P < .001).

• Remission of type 2 diabetes was higher in patient with:•More weight loss•Lower baseline HbA1c levels

http://www.obesityonline.org/slides/slide01.cfm?tk=45&pg=2

conclusion

• Bariatric surgery frequently result in resolution of obesity-related comorbidities (40 to 90% of patients).

• This is significantly more effective than other interventions

• Possible mechanisms of this resolution includes:– Weight Loss– Decrease food intake.– Changes in gut hormones secreation

• Bariatric surgery is powerful tool for management of obesity and its related comorbidities if all of the following factors assured:– Proper patient selection.– Good surgeon and right type of procedure.– Life long follow up including:

» Monitoring of complications.» Nutritional monitoring.» Adjustment of medications.» Counseling.

• Required multidispinary approach.• Several studies suggest that patient with poor follow-up

have worse outcomes.

Weight loss with recombinant methionyl human leptin     

Heymsfield, SB, JAMA 1999