Bariatric Surgery Principles

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Indications & Criteria - Who Gets the Cut?

  • General International Criteria:
    • BMI $\ge$ 40 kg/m² (Class III obesity).
    • BMI $\ge$ 35 kg/m² (Class II) with $\ge$1 significant comorbidity (e.g., T2DM, HTN, severe OSA, NAFLD/NASH, dyslipidemia).
  • Indian MOHFW / OSSI Guidelines:
    • BMI $\ge$ 37.5 kg/m².
    • BMI $\ge$ 32.5 kg/m² with $\ge$1 significant comorbidity.
    • BMI $\ge$ 30 kg/m² with uncontrolled T2DM or metabolic syndrome (selected cases).
  • Essential Prerequisites:
    • Age: Typically 18-65 years (individualized assessment).
    • Documented failure of supervised non-surgical weight loss (e.g., >6 months).
    • Acceptable operative risk; no contraindications.
    • Psychologically stable, well-informed, motivated, and committed to lifelong follow-up.

⭐ Indian guidelines may recommend surgery at BMI $\ge$ 30 kg/m² for patients with uncontrolled Type 2 Diabetes or severe metabolic syndrome.

Management Recommendations for Overweight and Obesity

Surgical Options - Procedure Parade

  • Mechanisms:
    • Restrictive: Smaller stomach pouch → early satiety. Ex: Laparoscopic Sleeve Gastrectomy (LSG) - removes ~80% stomach; ↓Ghrelin.
    • Malabsorptive: Bypasses small intestine → ↓nutrient absorption. Ex: Biliopancreatic Diversion/Duodenal Switch (BPD/DS).
    • Mixed: Combines restriction & malabsorption. Ex: Roux-en-Y Gastric Bypass (RYGB), One Anastomosis Gastric Bypass (OAGB/MGB).
ProcedurePrimary Type(s)EWL%Key Advantage(s)Key Disadvantage(s)
LSGRestrictive50-60Simpler; Preserves pylorus; ↓GhrelinGERD risk; Irreversible; Less metabolic effect
RYGBMixed (Restrictive > Malabsorptive)60-70Gold standard; Excellent T2DM resolution; Anti-refluxMore complex; Dumping syndrome; Nutrient deficiencies
OAGB/MGBMixed (Malabsorptive > Restrictive)65-75Simpler than RYGB; Potent metabolic effectsBile reflux; Higher risk of severe malnutrition

Patient Prep & Care - Smooth Sailing Surgery

  • Pre-operative Phase:
    • Comprehensive assessment:
      • Nutritional: Screen & correct deficiencies (Iron, B12, Vit D, protein).
      • Psychological: Evaluate readiness, identify contraindications (e.g., active substance abuse).
      • Medical: Optimize comorbidities (DM, HTN, OSA).
    • Mandatory: Smoking cessation >6 weeks prior.
    • Pre-op diet: Low-Calorie Diet (LCD) for 2-4 weeks to shrink liver.
  • Intra-op & Immediate Post-op:
    • Anesthesia: Consider Rapid Sequence Intubation (RSI), use lung-protective ventilation.
    • VTE Prophylaxis: Essential! Mechanical (SCDs) + Pharmacological (LMWH).
    • Pain control: Multimodal approach.
  • Early Post-operative Care:
    • Diet Progression: Gradual (Clear liquids → Full liquids → Pureed → Soft → Regular diet over weeks). 📌 Mnemonic: Can Lions Pounce Softly Regularly?
    • Monitoring: Vigilance for leaks, bleeding, infection, VTE.

⭐ Early ambulation (within hours post-op) significantly reduces VTE risk and aids recovery.

Aftermath & Outlook - The Long Game

  • Early Complications (<30 days):
    • Anastomotic leak (⚠️ tachycardia >120bpm often earliest sign)
    • Hemorrhage, Venous Thromboembolism (VTE), infection
  • Late Complications (>30 days):
    • Nutritional Deficiencies:
      • Iron (most common post-RYGB)
      • Vitamin B12 (neuropathy risk)
      • Folate
      • Calcium & Vitamin D (bone health)
      • Thiamine (Wernicke's encephalopathy risk)
      • Protein malnutrition
    • GI Issues:
      • Strictures, marginal ulcers
      • Internal hernias (esp. post-RYGB)
      • Cholelithiasis (due to rapid weight loss)
      • Dumping syndrome (early/late types)
    • Weight regain, GERD (variable by procedure)
  • Lifelong Management & Follow-up:
    • Multidisciplinary team (MDT) essential
    • Regular monitoring: nutritional labs, weight, comorbidities
    • Lifelong vitamin/mineral supplementation
    • ⭐ Iron deficiency is the most common long-term nutritional deficiency after Roux-en-Y Gastric Bypass (RYGB).

    • Addressing weight regain: lifestyle, medical, endoscopic, or revisional surgery.

High‑Yield Points - ⚡ Biggest Takeaways

  • Indications: BMI ≥ 40 or BMI ≥ 35 with comorbidities (e.g., T2DM, HTN).
  • Mechanisms: Restriction, malabsorption, and favorable neurohormonal changes (↑GLP-1, PYY).
  • RYGB combines restriction & malabsorption; Sleeve Gastrectomy (SG) is primarily restrictive.
  • SG is currently the most performed bariatric procedure worldwide.
  • Key late complications: Nutritional deficiencies (Fe, B12, Ca, Vit D), dumping syndrome, internal hernias.
  • Lifelong vitamin/mineral supplementation and multidisciplinary follow-up are mandatory.

Practice Questions: Bariatric Surgery Principles

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Which of the following is not the criteria for diagnosis of Metabolic syndrome?

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Flashcards: Bariatric Surgery Principles

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The following bariatric procedure is also known as _____

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The following bariatric procedure is also known as _____

biliopancreatic diversion

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