Bariatric Surgery Principles

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.

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).

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.