Gastric surgery procedures

🗺️ Anatomy - Stomach's Street Map

• Arterial Supply (from Celiac Trunk):
  • Lesser Curve: Left Gastric a. (from celiac) & Right Gastric a. (from proper hepatic).
  • Greater Curve: Left Gastro-omental a. (from splenic) & Right Gastro-omental a. (from gastroduodenal).
  • Fundus: Short Gastric aa. (from splenic).
• Venous Drainage: Veins parallel arteries, draining into the Portal System.
• Innervation:
  • Parasympathetic: Vagus n. (Anterior & Posterior trunks).
  • Sympathetic: Celiac plexus.
• Lymphatics: Follow arteries; crucial for gastric cancer staging.

⭐ Surgical Pitfall: A posterior duodenal/gastric ulcer can erode into the gastroduodenal artery or splenic artery, respectively, causing massive hemorrhage. The pancreas lies posterior to the stomach.

✂️ The Gastric Nip/Tuck

Surgical procedures for peptic ulcer disease (PUD), malignancy, or bariatric goals.

• Gastrectomy: Resection of the stomach.

  • Partial (Antrectomy): Removes antrum; reduces gastrin production.
  • Total: For extensive cancer (e.g., linitis plastica). Requires esophagojejunostomy.

• Anastomosis Types (Post-Gastrectomy):

  • Billroth I (Gastroduodenostomy): Stomach remnant attached to duodenum.
  • Billroth II (Gastrojejunostomy): Stomach remnant attached to jejunum. Creates a blind duodenal (afferent) loop.
  • Roux-en-Y: Used in bariatrics and cancer surgery. Creates a small gastric pouch anastomosed to a "Roux limb" of jejunum.

📌 Billroth I is 1 limb (duodenum). Billroth II has 2 limbs (duodenal stump + jejunal loop).

⭐ Dumping Syndrome: A common complication, especially after Billroth II & Roux-en-Y. Rapid emptying of hyperosmolar chyme into the small intestine causes fluid shifts, leading to hypotension, tachycardia, and diarrhea.

🔪 Management - The Bypass Blueprint

• Roux-en-Y Gastric Bypass (RYGB): Gold standard bariatric procedure combining restriction & malabsorption.
• Anatomy:
  • A small gastric pouch (~30 mL) is created from the fundus.
  • Stomach, duodenum, & proximal jejunum are bypassed.
  • Roux limb (alimentary) connects to the pouch.
  • Biliopancreatic limb carries digestive juices.
  • Limbs join at the common channel for absorption.
• Physiology: ↓ Ghrelin (hunger), ↑ GLP-1 & PYY (satiety).

⭐ Key Complications & Deficiencies:

• Dumping Syndrome: Rapid gastric emptying.
• Nutritional: Iron, B12, Folate, Calcium, Vit D.
• Surgical: Anastomotic leak/stenosis, marginal ulcers.

🚑 Complications - The Aftermath

• Dumping Syndrome: Rapid emptying of hyperosmolar contents into small bowel.
  • Early: 15-30 min post-meal. Osmotic fluid shift → hypovolemia, autonomic response (tachycardia, palpitations, diaphoresis, diarrhea).
  • Late: 2-3 hrs post-meal. Rapid glucose spike → exaggerated insulin release → reactive hypoglycemia (dizziness, confusion).
• Alkaline Reflux Gastritis: Bile reflux into stomach remnant → burning epigastric pain, N/V, unrelieved by vomiting.
• Afferent Loop Syndrome (Billroth II): Obstruction of afferent limb → stasis, bacterial overgrowth → postprandial pain, bloating, relieved by projectile bilious vomiting.
• Anemia:
  • Iron deficiency (duodenum/proximal jejunum bypass).
  • Vitamin B12 deficiency (loss of parietal cells → ↓intrinsic factor).

⭐ Post-gastrectomy, patients often require lifelong vitamin B12 injections and iron supplementation due to malabsorption.

⚡ Biggest Takeaways

• Roux-en-Y Gastric Bypass (RYGB) is both malabsorptive and restrictive; monitor for iron, B12, folate, and calcium deficiencies.
• Sleeve Gastrectomy is purely restrictive, removing the fundus and decreasing ghrelin production.
• Dumping syndrome is a key post-gastrectomy complication due to rapid emptying of hyperosmolar contents.
• Anastomotic leak is the most feared early complication; suspect with unexplained post-op tachycardia.
• Vagotomy reduces acid but impairs motility, often requiring a drainage procedure like pyloroplasty.
• Billroth II reconstruction carries a higher risk of dumping and afferent loop syndrome than Billroth I.