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 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 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 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

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%