Bacterial translocation after mesenteric ligation in dogs

Computed tomographic imaging findings of bowel ischemia

LEARNING OBJECTIVES

Learning objectives of this paper are to review and to summarize the pathogenesis of bowel ischemia and to describe its clinical, pathological, and radiological manifestations.

BACKGROUND

Bowel ischemia is a common disorder produced by several causes, and it shows various clinical presentations connected with an high mortality. With the increase in average life expectancy, bowel ischemia represents one of the most threatening abdominal conditions in elderly patients. In the last decade, computed tomography has tremendously altered the diagnostic approach to bowel ischemia also influencing the therapeutic approach in the current practice.

IMAGING FINDINGS

Computed tomographic imaging findings include bowel wall thickening, portal venous gas, intramural pneumatosis, engorgement of mesenteric veins, loss or increase of bowel wall enhancement, and infarction of other abdominal organs.

CONCLUSIONS

Bowel ischemia shows a broad spectrum of radiological manifestations, and regardless of the primary causes, it produces similar radiological features. Bowel ischemia may simulate cancer or inflammatory conditions; so it is a mandatory tight integration between radiological and clinical signs.

CT of acute bowel ischemia

Bowel ischemia may be caused by many conditions and manifest with typical or atypical and specific or nonspecific clinical, laboratory, and radiologic findings. It may mimic various intestinal diseases and be confused with certain nonischemic conditions clinically and at computed tomography (CT). Bowel ischemia severity ranges from mild (generally transient superficial changes of intestinal mucosa) to more dangerous and potentially life-threatening transmural bowel wall necrosis. Causes of critically reduced blood flow to the bowel are diverse, ranging from occlusions of mesenteric arteries or veins to complicated bowel obstruction and overdistention. CT can demonstrate changes in ischemic bowel segments accurately, is often helpful in determining the primary cause of ischemia, and can demonstrate important coexistent findings or complications. Unfortunately, common CT findings in bowel ischemia are not specific, and specific findings are rather uncommon. Therefore, it often is a combination of nonspecific clinical, laboratory, and radiologic findings-especially detailed knowledge about the pathogenesis of acute bowel ischemia in different conditions-that helps most in correct interpretation of CT findings. To improve understanding of this complex heterogeneous entity, this article provides an overview of the anatomy and physiology of mesenteric perfusion and discussions of causes and pathogenesis of acute bowel ischemia, CT findings in various types of acute bowel ischemia, and potential pitfalls of CT.

Gastrointestinal complications in the intensive care unit

Pathologic conditions affecting the abdomen are a significant cause of morbidity and mortality in the intensive care unit, but their importance is not widely recognized. This article presents several aspects of abdominal pathology that can occur in intensive care unit patients. This pathology may have a considerable impact on the prognosis and survival of the critically ill patient. The diagnostic contribution of laboratory tests and imaging is discussed. Conditions such as the abdominal compartment syndrome, acute mesenteric ischemia, gastrointestinal bleeding, diarrhea, abdominal sepsis, complications of entereal and parenteral nutrition, and ileus in critically ill patients are also reviewed.