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 LCardia, Fundus, Body, Antrum & PylorusPyloric sphincter- regulates gastric emptying

& prevents refluxWall - Four layers Mucosa, Submucosa,

Muscularis & Serosa

Anatomy

Types of cells & secretion

Functions

A-Food breakdown to form chyme - mechanical digestion and - acid and pepsin actionB-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 cellsHCl, 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 gastritisAcute 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 biopsyB- Barium mealC- Blood studies ↓ hemoglobin (Hgb) shows

chronic blood lossD-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 _ bleedingB - Intractability

Complications of PUD

Perforated peptic ulcer

- Sex ratio 2:1 , age 45-55 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 painPale, anxiousRaised pulse rateAbdomen still, not moving with respiration tender,

board like rigidityAfter 6 hrs peritonitis - silent abdominal distentionErect plain abdominal x-ray/CXR - air under

diaphragm

Air under diaphragm

Treatment

ResuscitateAntibiotic therapyContinuous gastric aspiration Urgent laparotomy - peritoneal toilet and

closure of perforation with omental patchAnti 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 40-60 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 - AdenocarcinomaSpread -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 surgeryPrognosis - Over all 5 years survival is about 10 -

20%