Gastric Ischaemia

Gastric ischaemia is inadequate blood supply to the stomach causing mucosal injury, ulceration or full thickness necrosis. It is uncommon because of a rich collateral network from the coeliac axis, the superior mesenteric artery and the short gastric vessels.

Rare; most reports are single cases or small series. Mortality is high (over 40%) when necrosis occurs.

Causes are atherosclerotic coeliac or superior mesenteric artery stenosis, embolism, vasculitis, aortic dissection, low flow states and shock, vasopressors, cocaine use, gastric volvulus or dilatation, embolisation of left gastric branches, gastric conduit after oesophagectomy, radiotherapy and cirrhosis with portal hypertension.

Pathophysiology.

Reduced flow causes mucosal hypoxia, loss of barrier function, acid injury and ulceration. Prolonged ischaemia leads to transmural necrosis, perforation and sepsis. Reperfusion adds to injury.

Epigastric pain (often postprandial), nausea, vomiting, haematemesis and melaena. Necrosis presents with severe pain, peritonitis, fever and shock.

Red flags.

• Shock or peritonism.
• Black or necrotic mucosa on endoscopy.
• Rising lactate.
• Portal venous gas or gastric wall gas on imaging.

Endoscopy shows pale, dusky, blue black or sloughing mucosa with irregular ulcers, usually in the fundus and body. Biopsies show coagulative necrosis. CT angiography shows vascular occlusion, wall thickening, reduced enhancement, intramural gas and portal venous gas. Send lactate, blood gas, full blood count, and vasculitis and thrombophilia tests as indicated.

Differential diagnosis.

• Peptic ulcer disease.
• Phlegmonous or emphysematous gastritis.
• Caustic injury.
• Gastric cancer.
• Acute gastric dilatation.
• Mesenteric ischaemia with gastric involvement.

Resuscitate, correct the cause of low flow and secure imaging early. Operate for necrosis or perforation.

• Pantoprazole: 40 mg IV twice daily; until oral therapy is possible, then 40 mg orally once daily for 8 weeks; maximum 80 mg daily for this indication; monitor symptoms and magnesium; reduce to 20 mg daily in severe hepatic impairment.
• Piperacillin-tazobactam (necrosis or sepsis): 4.5 g IV every 6 hours for 5 to 7 days after source control; maximum 18 g daily; monitor renal function and blood counts; reduce for creatinine clearance under 40 mL/min.
• Unfractionated heparin (thrombosis or embolism, once bleeding is controlled): 80 units/kg IV bolus (maximum 5,000 units), then 18 units/kg/h; adjusted to anti-Xa 0.3 to 0.7 units/mL; monitor platelets and bleeding; use lower doses in renal impairment.

Revascularise by endovascular or open surgery when an occlusive lesion is found. Resect necrotic stomach and drain the abdomen.

Monitoring. Haemodynamics, lactate every 2 to 4 hours, haemoglobin, abdominal examination and repeat endoscopy at 48 to 72 hours in conservative cases.

Referral and escalation. Urgent upper gastrointestinal and vascular surgery, interventional radiology and critical care.

Special groups. Patients with a gastric conduit need urgent endoscopic assessment of the conduit for dusky mucosa.