Computed tomography evaluation of intestinal ischemia

Ischemic colitis: A forgotten entity. Results of a retrospective study in 118 patients

OBJECTIVE

The aim of our study was to document our 6-year experiences in identifying the clinical characteristics, laboratory findings, risk factors and the outcomes of patients with ischemic colitis (IC) in a community hospital setting.

METHODS

The medical records of patients who were diagnosed with IC from 2007 to 2013 in two community hospitals were retrospectively reviewed. Their clinical characteristics, laboratory results, radiological, endoscopic and histological evidence, anatomic location of the lesion, comorbidities, concomitant use of drugs, and so on, were collected.

RESULTS

A total of 118 patients with IC was identified, most were elderly individuals with a female predominance. The most common symptoms were abdominal pain, rectal bleeding and diarrhea. Hypertension, hyperlipidemia, coronary artery disease and diabetes mellitus were the most common comorbidities. Erythema, edema and erosions/ulcerations were the most common endoscopic findings. Left colon was the most affected location of lesion (84.8%), and there was one case of pancolitis. The descending colon was the most common affected segment, while rectum was the least affected segment. Severe IC occurred in 12.7% of the patients. Death within 30 days from the diagnosis of the disease occurred in 4.2%.

CONCLUSIONS

IC is majorly occurred in elderly with a female predominance. Cardiovascular disease and its associated risk factors are the most common comorbidities. Left colon is the most affected location of the disease and the overall mortality rate was 4.2%. Physicians should make every effort to identify these patients, especially those with high risks.

Surgical Management of Severe Colitis in the Intensive Care Unit

Severe colitis, an umbrella encompassing several entities, is one of the most common acute gastrointestinal disorders resulting in critical illness. Clostridium difficile infection is responsible for the majority of nosocomial diarrhea with fulminant C difficile colitis (CDC) carrying a high mortality. Optimal outcomes can be achieved by early identification and treatment of fulminant CDC, with appropriate surgical intervention when indicated. Ischemic colitis, on the other hand, is uncommon with a range of etiological factors including abdominal aortic surgery, inotropic drugs, rheumatoid diseases, or often no obvious triggering factor. Most cases resolve with nonsurgical management; however, prompt recognition of full-thickness necrosis and gangrene is crucial for good patient outcomes. Fulminant colitis is a severe disease secondary to progressive ulcerative colitis with systemic deterioration. Surgical intervention is indicated for hemorrhage, perforation, or peritonitis and failure of medical therapy to control the disease. Although, failure of medical management is the most common indication, it can be difficult to define objectively and requires a collaborative multidisciplinary approach. This article proposes some simple management algorithms for these clinical entities, with a focus on critically ill patients.

Is CT Angiogram of the Abdominal Vessels Needed following the Diagnosis of Ischemic Colitis? A Multicenter Community Study

Background. CT angiogram is frequently obtained after diagnosis of ischemic colitis (IC). Aims. To investigate the vascular findings of CT angiogram as compared to contrast-enhanced CT scan and whether this modality changes the management or prognosis of IC. Methods. We conducted a retrospective analysis of patients with IC from 2007 to 2013. Results. CT angiogram was performed in 34 patients (28.81%), whereas contrast-enhanced CT scan was performed in 54 patients (45.76%). In CT angiogram group, 8 patients (23.5%) had atherosclerotic changes. Stenosis was found in 12 patients (35.3%) (9: celiac trunk, 3: SMA). Among this group, one patient underwent colectomy and another underwent angioplasty of the celiac trunk who died within 30 days. Among contrast-enhanced CT scan group, 5 patients (9.3%) had atherosclerotic changes. Stenosis was found in 5 patients (9.3%) (3: celiac trunk, 1: SMA, and 1: IMA). Among this group, 3 patients had colectomy and one died within 30 days. There was no statistical difference between both groups in all vascular findings except the stenosis which was higher in CT angiogram group (P = 0.0025). Neither the need for surgery nor all-cause mortality was different between both groups. Conclusion. CT angiogram did not provide any useful findings that altered the management or the prognosis of IC.

Computed tomography in patients with abdominal pain and diarrhoea: does the benefit outweigh the drawbacks?

The role of computed tomography (CT) in the evaluation of abdominal pain is well established. However, concern exists in regard to procedure-related radiation levels, contrast-medium toxicity and costs. We sought to determine whether the use of abdominal CT caused major changes in the management of patients who had abdominal pain and diarrhoea. We reviewed all abdominal CT examinations that were performed at our hospital from October through December 2010. We selected 574 scans that had been performed in patients who presented with or without diarrhoea. We examined the selected medical records to determine whether the CT scan changed patients' management. A scan was considered to be management changing if a decisive intervention occurred on the basis of the scan results. Among 124 scans in patients with diarrhoea and 450 scans in patients without diarrhoea, the scan results changed management in 13 of the patients with diarrhoea (11%) and in 233 of those without diarrhoea (52%) (P < 0.001). When management changed, the changes resulted from findings unrelated to diarrhoea. Despite its defined role in the assessment of abdominal pain, CT of patients that also had diarrhoea seldom caused a major change in management. The probability of CT causing such a change does not outweigh the cost, radiation risk or potential for contrast-induced nephropathy.

Transmural colonic ischemia: clinical features and computed tomography findings

Our purpose was to describe the computed tomography features of transmural colonic ischemia in correlation with clinical, laboratory and histopathological findings of 14 patients who underwent colectomy (9 female and 5 male; mean age, 68 years). Seven patients died (50%). Transmural necrosis involved the right colon in 10 patients (10/14, or 72%). Eleven patients showed thickened colonic wall (11/14, or 79%), 10 pneumatosis (10/14, or 71%), 5 gas in the portal venous system (5/14, or 36%), and 14 fat stranding (14/14, or 100%).

CT enterography: principles, trends, and interpretation of findings

Computed tomographic (CT) enterography is an emerging alternative to traditional fluoroscopy for the assessment of disorders of the small bowel. The greatly improved spatial and temporal resolution provided by multidetector CT scanners, combined with good luminal distention provided by negative oral contrast agents and with good bowel wall visualization, have made CT enterography the main imaging modality not only for investigating proved or suspected inflammatory bowel disease but also for detecting occult gastrointestinal tract bleeding, small bowel neoplasms, and mesenteric ischemia. CT enterography is particularly useful for differentiating between active and fibrotic bowel strictures in patients with Crohn disease, thus enabling selection of the most appropriate treatment (medical management or intervention) for an improved outcome. CT enterography allows excellent visualization of the entire thickness of the bowel wall and depicts extraenteric involvement as well, providing more detailed and comprehensive information about the extent and severity of the disease process.

Imaging in intestinal ischemic disorders

Intestinal ischemia and infarction are a heterogeneous group of diseases that have as their unifying theme hypoxia of the small bowel or colon. The incidence of bowel ischemia and infarction is on the rise for several reasons: the aging of the population, the ability of intensive care units to salvage critically ill patients, and heightened clinical awareness of these disorders. Improvements in diagnostic imaging techniques have greatly contributed to the earlier diagnosis of intestinal ischemia, which can have a positive influence on patient outcomes. In this article, role of radiology in the detection, differential diagnosis, and management of patients who have intestinal ischemia and infarction is discussed.

CT imaging of colitis

Computed tomography (CT) is widely used to assess patients with nonspecific abdominal pain or who are suspected of having colitis. The authors recommend multidetector CT with oral, rectal, and intravenous contrast material and thin sections, which can accurately demonstrate inflammatory changes in the colonic wall and help assess the extent of disease. In most cases, the final diagnosis of the type of colitis is based on clinical and laboratory data and colonoscopic and biopsy findings, but specific CT features help narrow the differential diagnosis. Ulcerative colitis is distinguished from granulomatous colitis (Crohn disease) in terms of location of involvement, extent and appearance of colonic wall thickening, and type of complications. Ulcerative colitis and Crohn disease (granulomatous colitis) are rarely associated with ascites, which is often seen in infectious, ischemic, and pseudomembranous colitis. Pseudomembranous colitis also demonstrates marked wall thickening and, occasionally, skip areas but is associated with broad-spectrum antibiotic treatment or chemotherapy. Neutropenic colitis is characterized by right-sided colonic and ileal involvement, whereas ischemic colitis is characterized by vascular distribution pattern and history. Diverticulitis is a focal asymmetric process with fascial thickening and inflamed diverticula. Dilatation of a thick-walled appendix with increased enhancement and adjacent stranding suggests appendicitis, but inflammatory changes may extend to the cecum and terminal ileum. Epiploic appendagitis is a focal rim-enhancing area next to the colon, usually without any substantial colonic wall thickening.

Acute bowel ischemia: CT findings

Acute bowel ischemia represents one of the most dramatic abdominal emergencies and, despite the fact it is more and more frequently observed in clinical practice, its mortality rate remains very high. In recent years Computed Tomography (CT) has proved to be a valid diagnostic tool in the evaluation of patients with acute abdominal syndrome and in the visualization of early signs of bowel ischemia. This paper reviews the aetiological and pathophysiological aspects as well as a broad spectrum of CT findings of this clinical condition.

Imagerie des ischémies intestinales

Ischemic bowel disease includes acute and chronic mesenteric ischemia, and colon ischemia. Cross-sectional imaging, and more particularly computed tomography, has an increasing role in the detection of acute and chronic mesenteric ischemia. Vascular obstructions or stenoses and changes in the bowel wall can be observed. Functional information can be added with MRI by using sequences that are sensitive to oxygen saturation in the superior mesenteric vein. Arteriography remains the reference examination in patients with acute mesenteric ischemia.

CT in acute mesenteric ischaemia

Enhanced computed tomography (CT) is frequently performed for possible bowel ischaemia. It has the distinct advantage of possible detection of the causes of ischaemia. Radiologists therefore need to be familiar with the spectrum of diagnostic CT signs. We present the CT imaging findings in surgically proven cases of small bowel ischaemia. In addition to signs pertaining to the underlying aetiological pathology, bowel dilatation, bowel wall thickening, mural gas, occlusion of mesenteric vessels, ascites and infarct of other abdominal organs were observed.

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.

Noninvasive assessment of portomesenteric venous thrombosis: current concepts and imaging strategies

Rapid, noninvasive imaging strategies, especially multidetector spiral CT and CT angiography (CTA) as well as gadolinium-enhanced MR angiography (MRA), have facilitated early diagnosis of splanchnic venous thrombosis, a potentially lethal cause of intestinal ischemia. Single breath-hold volumetric acquisitions permit superior temporal and contrast resolution while eliminating motion artifact and suppressing respiratory misregistration. Increased spatial resolution is aided by thinner slice collimation. These cross-sectional imaging techniques are becoming a preferred noninvasive alternative to conventional selective mesenteric angiography with delayed imaging for venous evaluation and should be considered the primary diagnostic modalities for evaluating patients with high clinical suspicion of nonsurgical mesenteric ischemia.