STOMACH AND DUODENUM Begashaw m (MD)

Introduction  PUD is a common problem  Helicobacter pylori (H. pylori) - important associated risk factor  Gastric cancer -One of the top five cancers -Worst prognosis - difficulty to diagnose -High index of suspicion

Stomach Anatomy  Asymmetric dilation of the proximal gastro intestinal tract  Capacity-1.5 to 2.0 L Cardia, Fundus, Body, Antrum & Pylorus Pyloric sphincter- regulates gastric emptying & prevents reflux Wall - Four layers Mucosa, Submucosa, Muscularis & Serosa

Anatomy

Types of cells & secretion

Functions A-Food breakdown to form chyme - mechanical digestion and - acid and pepsin action B-Reservoir through receptive relaxation  Phases of gastric secretion _Cephalic - Acetylcholin by the vagus nerve _Gastric - Gastrin (by G cells) _Intestinal - mainly inhibitory - Secretin

Histology  Surface epithelial cells alkaline mucus  Mucus cells_mucus, HCO3¯  Parietal cells  HCl, Intrinsic factor  Chief cells  pepsinogens, lipases

Pathogenesis imbalance in aggressive activity of acid & pepsin & defensive mechanisms Factors 1. Helicobacter pylori 2. NSAIDs - aspirin 3. Acid hypersecretion 4. Rapid gastric emptying 5. Impaired duodenal acid disposal 6. Impaired gastric mucosal defense 7. Duodenogastric reflux

Classification Erosive gastritis Acute gastritis - after major trauma, shock, sepsis, head Injury & ingestion of aspirin & alcohol -“Stress erosion” Chronic gastritis->Established inflammatory reaction

Duodenal ulcer -occurs in the proximal duodenum with in 1 to 2 cm of the pylorus & there is acid hyper secretion Gastric ulcer_ acid secretion is either normal or decreased

Classification

Summary of clinical features

Investigations A- Gastroduodenoscopy and biopsy B- Barium meal C- Blood studies ↓ hemoglobin (Hgb) shows chronic blood loss D-H.pylori test

Treatment Medical treatment  Acid reduction - H2 – receptor antagonists– cimetidine 800 mg/night for 6 wks - Proton pump inhibitor – omeprazole 20 mg/day - Irritants_avoid  Anti H. pylori treatment -Bismuth tablets -Amoxicillin for 2 – 4 weeks -Metronidazole

Surgical treatment A - Complications – obstruction _ perforation _ bleeding B - Intractability

Complications of PUD Complications of PUD

Perforated peptic ulcer - Sex ratio 2:1, age years - Anterior surface of duodenum (location) - Past history of PUD is common - Gastric contents spill over the peritoneum and bring about peritonism which will be followed by bacterial peritonitis after 6 hours

Clinical features Sudden onset of abdominal pain Pale, anxious Raised pulse rate Abdomen still, not moving with respiration tender, board like rigidity After 6 hrs peritonitis - silent abdominal distention Erect plain abdominal x-ray/CXR - air under diaphragm

Air under diaphragm

Treatment Resuscitate Antibiotic therapy Continuous gastric aspiration Urgent laparotomy - peritoneal toilet and closure of perforation with omental patch Anti H-pylori treatment - recurrence

Omental patch

Graham patch technique

Bleeding Peptic Ulcer - Slight bleeding -trauma from solid food - Severe hemorrhage - erosion of an artery at the base of the ulcer located posteriorly (gastoduodenal, splenic) - Patient presents with hematemesis and/or melena

Management  Conservative - IV fluid resuscitation - Blood transfusion if indicated - Naso gastric tube insertion and saline lavage - H2 receptor antagonist - Endoscopic evaluation - Serial hematocrit

Gastric Outlet Obstruction- GOO results from cicatrisation and fibrosis due to long standing duodenal or juxtapyloric ulcer Clinical feature - pain, fullness, vomiting of large foul smelling vomit - peristaltic wave from left to right - succussion splash - electrolyte disturbance and metabolic alkalosis - Barium meal-large stomach full of food residue with delay in evacuation

Treatment Surgery – truncal vagotomy and bypass operation after preliminary gastric lavage with saline for 4-5 days Correction of fluid and electrolytes using crystalloid fluids

Gastric Cancer Epidemiology - Age years - Sex M:F 3:1 More common in Far East – Japan Etiology Premalignant conditions Risk factors: Gastric polyp,pernicious anemia, post gastrectomy stomach, gastritis, cigarette smoking & genetic makeup

Pathology - Prepyloric region is the most common site - Microscopic - Adenocarcinoma Spread -Direct -lymphatic -transperitoneal -blood stream

Clinical features New onset dyspepsia -above 40 yrs Anorexia,loss of weight Anemia, tiredness, weakness, pallor Persistent pain with no response to medical treatment Gastric distention Dysphagia or fullness, belching, vomiting Other signs - Virchow’s nodes, Krukenberg tumor - Abdominal mass - Ascites

Gastric ca

Investigations - Gastroscopy and biopsy - Hgb - Barium meal shows filling defect - Laparotomy (diagnostic)

Treatment - Gastrectomy when possible - Palliative bypass surgery Prognosis - Over all 5 years survival is about %