| Print Date: | May 18, 2013, 10:19 pm |
| Title | Acute thromboembolism of the superior mesenteric artery secondary to atrial fibrillation |
| Text | Atrial fibrillation is a common cause of thromboembolic phenomena. Other causes of thromboembolic phenomena include mitral valve disease, atherosclerosis, and hypercoagulability.
Along with stroke and acute limb ischemia, acute mesenteric ischemia may be a sequela of thromboembolism secondary to atrial fibrillation. If an embolus lodges distal to the origin of the superior mesenteric artery and obstructs collateral flow from the gastroduodenal and middle colic arteries, the bowel becomes ischemic immediately. Severe acute mesenteric ischemia is a surgical/interventional emergency. Mortality exceeds 80% without early and aggressive intervention. Patients typically present with sudden onset abdominal pain out of proportion to the physical findings, followed by nausea, vomiting, and diarrhea. Peritoneal signs on physical exam evolve late in the (rapid) course of the disease and usually occur shortly before sepsis and shock. While no laboratory findings are specific, the white blood cell count and blood pH of these patients will be elevated. Because of its speed and multiplanar reconstruction capability, intravenous contrast enhanced MDCT is the preferred imaging modality to evaluate for acute vascular injury or obstruction. Catheter directed pharmaceutical arterial thrombolysis and endovascular mechanical thrombolysis can be successful but put the patient at risk of sepsis and renal failure secondary to a reperfusion syndrome. The more conservative management option is surgical thromboembolectomy or arterial bypass. If the diagnosis and treatment of acute mesenteric ischemia are delayed, the surgeon will also need to resect nonviable bowel. Other causes of acute mesenteric ischemia include trauma and aortic dissection. While no laboratory findings are specific, the white blood cell count and blood pH of these patients will be elevated. Because of its speed and multiplanar reconstruction capability, intravenous contrast enhanced MDCT is the preferred imaging modality to evaluate for acute vascular injury or obstruction. Catheter directed arterial thrombolysis can be successful but puts the patient at risk of sepis and renal failure secondary to reperfusion , as has suction embolectomy. Most patients receive surgical embolectomy or bypass with resection of nonviable bowel. |
| References: | “Treatment of Chronic Atrial Fibrillation.” Current Medical Diagnosis and Treatment, 39th Ed. New York: McGraw-Hill, 2000. Pg. 406-407.
“Acute Mesenteric Ischemia.” Vascular and Interventional Radiology: The Requisites, 1st Ed. St. Louis: Mosby, 2004. Pgs. 294-296. |
| Contributor | Joel McFarland (National Naval Medical Center Bethesda) |
| Peer Reviewer | Michael A Winkler (University of Kentucky) |
| Record Number | : 7110 |
| Created | 2006-03-22 16:18:18-05 |
| Modified | 2006-09-15 20:45:34-04 |
| Category: | Vascular |
| Location: | Abdomen - Generalized |
| Sublocation: | Mesentery and Omentum |
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