This document discusses the pathogenesis, diagnosis, and treatment of morbid obesity. It covers the chronic disease management model for primary care of patients with overweight and obesity. Key aspects include calculating BMI, assessing weight-related risks, setting weight loss and lifestyle goals, and referring patients for bariatric surgery if appropriate. The document also describes various bariatric surgery procedures like gastric banding, gastric bypass, sleeve gastrectomy, and duodenal switch. It provides details on patient selection, pre- and post-operative care, outcomes, and complications of these procedures.

1. Morbid Obesity
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2. INTRODUCTION

4. Pathogenesis
• Overweight develops
• lifestyle:
– sedentary
– sleep deprivation
– smoking cessation
• Diet:
– overeating
– fat and fast food intake
– night-eating syndrome and binge-eating disorder

5. pathogenesis
• Drug-induced:
– antipsychotics and antidepressants
– AEDs
– diabetic drugs
– Cyproheptadine, beta-blocker
• Neuroendocrine system
• Genetic and congenital disorders
– Prader-Will syndrome

6. https://consultqd.clevelandclinic.org/2015/07/managi
ng-psychosocial-risk-factors-in-bariatric-surgery-
patients/

7. The Chronic Disease Management
Model for Primary Care of Patients
with Overweight and Obesity

8. • Calculate BMI
• BMI 18-24.99:
– Advise to avoid weight gain and treat other risk
factors
– Calculate BMI annually by the clinician
• BMI ≥ 25
– Assess and treat CVD risk factors and obesity-
related comorbidities
• BP, FBS, lipid profile
• Waist circumference measurement: > 88cm in women,
102cm in men = increased CVD risk

9. • Assess weight and lifestyle history
– Determine the potential factors
– history of weight gain and loss over time, details
of previous weight loss attempts, dietary habits,
physical activity, family history of obesity, and
other medical conditions or medications that may
affect weight
– Attempt to lose weight and success

10. • Assess the need to lose weight
– BMI > 30 or 25-30 with risk factor
• Assess readiness to make lifestyle changes to
achieve weight loss
• Determine weight loss and health goals and
intervention strategies
– 5 – 10% weight loss within 6 months
– Caloric restriction: 1200-1500 kcal in women and
1500-1800 kcal in men
– Adjust medication

11. • High intensity comprehensive lifestyle
intervention
– Moderately-reduce caloric diet
– Increase physical activity > 200 min/week
– Behavioral changes
• BMI ≥ 30 or ≥ 27 with comorbidity
– Adding pharmacotherapy as an adjunct to lifestyle
modification
– Orlistat: reduce intestinal fat absorption
– Rimonabant
– Sibutramine  out

12. • BMI ≥ 40 or ≥ 35 with comorbidity: refer to
bariatric surgeon
• Weight loss ≥ 5% = success: follow up and
weight loss maintenance
• If not, refer to specialist

13. Principles of Bariatric Surgery

14. Types of commonly performed bariatric
operations by mechanism of action
• Primarily restrictive
– Laparoscopic adjustable gastric banding (LAGB)
– Sleeve gastrectomy (SG)
• Primarily malabsorptive
– Biliopancreatic diversion (BPD)
– Duodenal switch (DS)
• Combination
– Roux-en-Y gastric bypass (RYGB)

15. Potential Contraindications
• Severe medical disease making anesthesia or surgery
prohibitively risky (ASA class IV)
• Mentally incompetent to understand the procedure
• Inability or unwillingness to change lifestyle
postoperatively
• Drug, alcohol, or other addiction
• Active problem of bulimia or other eating disorder
• Psychologically unstable
• Nonambulatory status
• Unsupportive home environment

16. Indications
• BMI ≥ 40 kg/m2
• BMI 35 – 40 kg/m2 with comorbid medical
conditions
• Fail attempt at medically supervised diet
• Psychiatrically stable

17. Preoperative Issues
• Patient selection
• Preoperative preparation
• Anesthesiology issues

18. Patient Selection
• Insurance coverage
• Suitable for bariatric surgery by NIH criteria
• Patient’s motivation to change eating habit
• Assessment of eating habits, knowledge, self-
awareness, insight
• Psychological assessment

19. Preoperative Preparation
• Comorbidities with optimal therapy
• Look for hidden diseases:
– CAD  EKG, echo, CAG
– OSA  sleep study
– Asthma and hypoventilation syndrome of obesity
 pulmonary consultation
– GERD  EGD to rule out Barrett’s esophagus
– VTE  IVC filter?
– Perform US to rule out GS

20. Preoperative Preparation
• Smoking cessation: reduce risk of marginal
ulcer
• TFT to rule out hypothyroidism

21. Laparoscopic VS Open
• Minimize open technique complications:
incisional hernia and wound complications
• Earlier hospital discharge
• Lower 30-days complication rates
• Conclusion: favor laparoscopic

22. Brunicardi FC et al. Schwartz’s Principles of Surgery. 10th ed. McGraw-Hill Education, 2015.

23. Postoperative Follow-Up
• Short term: Up to 2 years
• More than 5 years
• The goals
– Maximize care postoperative period
– Assist in adjustment to new lifestyle patterns
– Alert and treat post-op complications
– Recommend measures to limit complications
• Objective data
– Weight loss
– Change in BMI
– Improvement in medical comorbidities

24. Laparoscopic Adjustable Gastric Banding
• Placement of inflatable sillicone band around
proximal stomach and allowing adjustment
tightness of the band

25. Brunicardi FC et al. Schwartz’s Principles of Surgery. 10th ed. McGraw-Hill Education, 2015.

26. Brunicardi FC et al. Schwartz’s Principles of Surgery. 10th ed. McGraw-Hill Education, 2015.

27. Brunicardi FC et al. Schwartz’s Principles of Surgery. 10th ed. McGraw-Hill Education, 2015.

28. LAGB: Patient Selection
• Not as difficult as other operations
• outpatient
• Offer to older, more medically ill, higher risk
patients
• efficacy of the operation in BMI >50 kg/m2 is
less impressive

29. LAGB: Post-Op Care and Follow-Up
• Band adjustment
• Multivitamin supplement
• Postoperative support group session

30. LAGB: Complications
• Prolapse
• Slippage
• Erosion
• Port and tube complications
• Failure to lose weight: more common than
other bariatric surgery

31. Prolapse
• Most common
• Clinical: post-op vomiting
• Pathogenesis: lower stomach was trapped
within the lumen of the band
• Evaluation: band in horizontal position

32. Slippage
• Reduced by pars flaccida technique

33. Laparoscopic Roux-en-Y Gastric Bypass
• Major feature of the operation is a proximal
gastric pouch of small size (often <20 mL) that
is totally separated from the distal stomach
• The biliopancreatic limb is 20-50 cm long from
ligament of Treitz
• Roux limb: 75-150 cm
• Longer limb, higher short-term weight loss

35. LRYGB: Patient Selection
• appropriate for most bariatric patients
• Contraindication
– previous gastric surgery
– previous antireflux surgery
– severe iron deficiency anemia
– distal gastric or duodenal lesions that require
ongoing future surveillance
– Barrett’s esophagus with severe dysplasia

36. LRYGB: Patient Selection
• EGD is required
• Mechanical bowel preparation is advised

37. LRYGB: Post-Op Care and Follow-Up
• Hospitalize for 2-3 days
• Major concerns: adequate analgesia,
adequate resuscitation, and early ambulation
• Employ post-op oral contrast study: to detect
edema, stenosis, or other obstructive lesions
at enteroenterostomy site  resulting gastric
dilation and staple line rupture

38. LRYGB: Outcomes
• Usually lose between 60% and 70% of excess
body weight during the first year after surgery
• Mortality less than 0.5%

39. LRYGB: Complications
• Post-op nutritional complication: IDA, vitB12 def,
vitD def
• Anastomotic leak
• venous thromboembolism
• wound infections
• marginal ulcers
• bowel obstruction
• postoperative transfusion
• Anastomotic stenosis

40. LRYGB: Complications
That Need Surgical Intervention
• Small bowel obstruction: from internal hernia
• Early postoperative vomiting with obstructive
picture
• Early postoperative hematemesis with
obstructive picture: from gastrojejunostomy
• Intestinal leak
• Postoperative bleeding

41. Biliopancreatic Diversion and
Duodenal Switch
• Resection of distal half to two-thirds
of the stomach and creation of an alimentary
tract of the most distal 200 cm of ileum
• Limited popularity

43. BPD with DS: Patient Selection
• Must be prepared the consequence of
malabsorption
• Frequent, voluminous bowel movement

44. BPD with DS: Post-Op Care
• Monitor nutritional status closely
• Same potential complication seen in RYGB

45. BPD with DS: Outcomes
• Weight loss results: excellent and durable
• Gallstone formation if not removed

46. Laparoscopic Sleeve Gastrectomy
• Rapidly increasing in popularity
• Advantage: easier operation than gastric
bypass, better outcome than gastric banding
• Indications:
– Super obesity (BMI> 60)
– Safe for both adolescent and elderly
– Contraindication: GERD, Barrett’s esophagus since
future esophagectomy

48. SG: Post-Op Care
• Same as LRYGB
• Absence of signs of bleeding and a
documented intact staple line with good
gastric emptying are required prior to
discharge.

49. SG: outcomes and complications
• Proximal staple line leakage: SG creates a high
luminal pressure tube
– Look for distal obstruction

50. References
Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation,
American Pharmacists Association, American Society for Nutrition, American Society for
Preventive Cardiology, American Society of Hypertension, Association of Black Cardiologists,
National Lipid Association, Preventive Cardiovascular Nurses Association, The Endocrine
Society, and WomenHeart: The National Coalition for Women with Heart Disease. 2013
AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults.
http://circ.ahajournals.org/content/circulationaha/early/2013/11/11/01.cir.0000437739.71
477.ee.full.pdf
Brunicardi FC et al. Schwartz’s Principles of Surgery. 10th ed. McGraw-Hill Education,
2015.
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