Mesenteric Artery Thrombosis Treatment & Management

Acute mesenteric artery thrombosis cannot be cured medically. If vasospasm is observed on arteriogram, intra-arterial papaverine may be started to improve flow, but it is not curative. Commence anticoagulation therapy immediately upon diagnosis. Thrombolytics have shown no benefit.

Surgical treatment involves exploratory laparotomy, followed by identification of the involved artery and bowel. Because thrombosis occurs at the origin of the vessel, the entire small bowel and proximal large bowel appear ischemic. In contradistinction, embolization of the SMA results in the proximal jejunum being spared, reflecting the more distal occlusion. Remove dead bowel and attempt reanastomosis. Open the affected artery and perform an endarterectomy.

Bypass techniques may also be performed using prosthetic grafts. If a patient is found to have perforated bowel on laparotomy, use an autogenous saphenous vein graft because of the decreased risk of graft infection.

Endovascular therapies have been described for chronic mesenteric ischemia, and some authors have tried thromboaspiration.^{[9, 10]} The criterion standard remains operative exploration to allow assessment of bowel viability.

Patients with acute ischemia should have immediate repletion of fluids and correction of any acid/base abnormalities; they should then undergo surgery without delay.

All patients should receive broad-spectrum antibiotic therapy prior to the start of the operation. Type and cross 4 units of packed red blood cells prior to surgery.

Assess the viability of the bowel during direct observation. Look for peristalsis and observe the color of the bowel (ie, pink and healthy vs red and edematous).

Intraoperative Doppler ultrasonography of the bowel can provide valuable information on the patency of the vessels. One gram of intravenous fluorescein followed by bowel examination under Wood lamp illumination can delineate poorly perfused bowel.

Treat mesenteric thrombosis by revascularization or endarterectomy.^[11] If not already started, begin anticoagulation therapy with intravenous heparin. Following reconstitution of arterial flow, the viability of the bowel is reassessed. Reassessment is based on clinical findings, including the color of the bowel and the presence or absence of palpable pulses.

Postoperative care should include close monitoring of blood pressure and hemoglobin level to evaluate for sepsis or hemorrhage.

Patients should continue to have postoperative heparin anticoagulation therapy in order to reduce thrombotic events, and papaverine may be administered to reduce vasospasm. Perform a 12-lead electrocardiogram to evaluate for myocardial dysfunction.

Patients can be expected to have a postoperative ileus due to bowel reperfusion.

Monitor patients closely because of the high likelihood of vascular disease in the rest of the arterial tree.

Determine cardiac and renal status at follow-up. Carotid duplex studies may be necessary if diffuse atherosclerotic disease is a strong possibility.

Because of the high incidence of atherosclerosis in patients with mesenteric ischemia, it is not surprising that one of the most common postoperative complications involves MI.

Prevention of postoperative MI involves preoperatively identifying correctable coronary artery disease. During the perioperative period, use a Swan-Ganz catheter to monitor fluid and cardiac function. Finally, when cross-clamping the supraceliac aorta, the anesthesiologist can ensure myocardial protection and afterload reduction to maximize cardiac output.

Acute renal failure in the immediate postoperative period can be prevented by keeping the patient well hydrated and administering mannitol before the aorta is cross-clamped.

Other possible complications include bleeding, infection, bowel infarction, prolonged ileus, and graft infection.

Unfortunately, the outcome of patients suffering from acute thrombosis is not as good as that of patients with chronic ischemia. The average mortality rate of patients with acute thrombosis is 75-80%.^[12]

For those patients who do survive, the risk of rethrombosis is high, and lifestyle may be hindered by a lifetime of total parenteral nutrition.

The diagnosis and treatment of acute mesenteric thrombosis have improved little since the late 20th century.

A retrospective study by Mamode et al found that 32% of patients were properly diagnosed prior to surgery or death. In this same review, 46 of 57 patients died from mesenteric ischemia.

Progress in the diagnosis of mesenteric thrombosis includes some advances in CT scanning and magnetic resonance imaging (MRI). While these modalities show promise, they are not the diagnostic tests of choice in suspected mesenteric thrombosis. In his study, Alpern et al found that 26% of patients were appropriately diagnosed as having ischemia by CT scan; other studies have shown similar results.

Treatment options of acute thrombosis center on surgical methods, which have changed little since the late 20th century. Some patients may be good candidates for percutaneous transluminal angioplasty with stenting, as was the patient reported by Bertran and colleagues.