Intestinal infarction secondary to mesenteric venous thrombosis: CT-pathologic correlation

Acute mesenteric ischemia secondary to oral contraceptive-induced portomesenteric and splenic vein thrombosis: A case report

BACKGROUND

Mesenteric ischemia represents an uncommon complication of splanchnic vein thrombosis, and it is less infrequently seen in young women using oral contraceptives. Diagnosis is often delayed in the emergency room; thus, surgical intervention may be inevitable and the absence of thrombus regression or collateral circulation may lead to further postoperative ischemia and a fatal outcome.

CASE SUMMARY

We report a 28-year-old female patient on oral contraceptives who presented with acute abdominal pain. Her physical examination findings were not consistent with her symptoms of severe pain and abdominal distention. These findings and her abnormal blood tests raised suspicion of acute mesenteric ischemia (AMI) induced by splanchnic vein thrombosis. Contrast-enhanced abdominal computed tomography revealed ischemia of the small intestine with portomesenteric and splenic vein thrombosis (PMSVT). We treated the case promptly by anticoagulation after diagnosis. We then performed delayed segmental bowel resection after thrombus regression and established collateral circulation guided by collaboration with a multidisciplinary team. The patient had an uneventful postoperative course and was discharged 14 d after surgery and took rivaroxaban orally for 6 mo. In subsequent follow-up to date, the patient has not complained of any other discomfort.

CONCLUSION

AMI induced by PMSVT should be considered in young women who are taking oral contraceptives and have acute abdominal pain. Prompt anticoagulation followed by surgery is an effective treatment strategy.

Many faces of acute bowel ischemia: overview of radiologic staging

Acute bowel ischemia (ABI) can be life threatening with high mortality rate. In spite of the advances made in diagnosis and treatment of ABI, no significant change has occurred in the mortality over the past decade. ABI is potentially reversible with prompt diagnosis. The radiologist plays a central role in the initial diagnosis and preventing progression to irreversible intestinal ischemic injury or bowel necrosis. The most single imaging findings described in the literature are either non-specific or only present in the late stages of ABI, urging the use of a constellation of features to reach a more confident diagnosis. While ABI has been traditionally categorized based on the etiology with a wide spectrum of imaging findings overlapped with each other, the final decision for patient’s management is usually made on the stage of the ABI with respect to the underlying pathophysiology. In this review, we first discuss the pathologic stages of ischemia and then summarize the various imaging signs and causes of ABI. We also emphasize on the correlation of imaging findings and pathological staging of the disease. Finally, a management approach is proposed using combined clinical and radiological findings to determine whether the patient may benefit from surgery or not.

Contrast-Enhanced CT for the Diagnosis of Acute Mesenteric Ischemia

OBJECTIVE. The purpose of this article is to provide an overview of the diagnostic and prognostic roles of CT in the management of acute mesenteric ischemia. CONCLUSION. Acute mesenteric ischemia is defined as inadequate blood supply to the gastrointestinal tract resulting in ischemic and inflammatory injury. The prognosis is poor without treatment. Contrast-enhanced CT has become the cornerstone of diagnosis to identify features of vascular disorders and of intestinal ischemic injury and to visualize bowel necrosis.

High-Value Multidetector CT Angiography of the Superior Mesenteric Artery: What Emergency Medicine Physicians and Interventional Radiologists Need to Know

The superior mesenteric artery (SMA) provides vital blood supply to the midgut, and an acute abnormality can rapidly precipitate bowel ischemia and infarction and lead to morbidity and mortality. Vascular diseases that acutely compromise the SMA threaten its tributaries and include occlusion, dissection, aneurysm rupture, pseudoaneurysm, vasculitis, and SMA branch hemorrhage into the bowel. Emergency medicine physicians rely on the radiologist to identify SMA abnormalities, to characterize them, and to detail findings that guide the appropriate triage of these patients. As such, radiologists must be cognizant of the features that influence patient treatment to assist vascular surgeons and interventional radiologists in decision making. Some patients can be treated medically, while clinical and radiographic findings may suggest the need for interventional or surgical repair of the artery. In the latter case, multidetector CT findings aid in determining which of the various surgical and endovascular treatment options is optimal, and both vascular and gastrointestinal sequelae of acute SMA abnormalities contribute to these determinations. The authors review acute life-threatening conditions involving the SMA including acute occlusion, dissection, aneurysm, pseudoaneurysm, and hemorrhage and discuss the vascular and gastrointestinal multidetector CT findings in each of these conditions that help to guide surgical and interventional management. ^©RSNA, 2019.

Small bowel stricture complicating superior mesenteric vein thrombosis

Superior mesenteric vein (SMV) thrombosis is a relatively rare disease. Most patients may be successfully treated with anti-coagulation alone. However, bowel stricture may develop due to intestinal ischemia which may require surgical treatment. This report describes a rare case of small bowel stricture occurring one month after successful treatment of SMV thrombosis. After segmental resection of strictured bowel, the patient's post-operative course was uneventful.

Role of multidetector CT angiography in the evaluation of suspected mesenteric ischemia

OBJECTIVE

To assess the role of multidetector CT angiography (MDCTA) in the diagnosis of acute mesenteric ischemia (AMI) and to compare the diagnostic utility of axial images with reconstructed images.

MATERIALS AND METHODS

In this Institute Review Board approved prospective study, MDCTA was performed on 31 patients who presented with the clinical suspicion of AMI (25M; 6F, age range: 16-73 years). Axial and reconstructed images of each patient were evaluated independently by two radiologists for evidence of bowel wall thickening, abnormal mucosal enhancement, bowel dilatation or obstruction, mesenteric stranding, ascites, solid organ infarcts, pneumatosis intestinalis or porto-mesenteric gas, and mesenteric arterial or venous occlusion. MDCT findings were correlated with the surgical findings and clinical outcome. Patients were later divided into two groups: a study group of patients with proven AMI and a control group of patients with an alternate diagnosis, for the purpose of statistical analysis.

RESULTS

AMI was correctly diagnosed in all 16 patients on MDCTA (100% sensitivity and specificity) of whom nine patients underwent surgical exploration. Three patients expired before surgery and the remaining 5 patients were proven based on positive clinical and laboratory findings. Mesenteric arterial occlusion was seen in 7 patients while 5 patients had portomesenteric venous thrombosis. Reconstructed images using minimum intensity projection, volume rendering and multiplanar volume reconstruction were found to perform better for the detection of vascular abnormalities and improved the diagnostic confidence of both radiologists in the evaluation of bowel and mesenteric abnormalities.

CONCLUSION

MDCTA is an effective non-invasive modality for the diagnosis of mesenteric ischemia.

Acute mesenteric ischemia induced by ligation of porcine superior mesenteric vein: multidetector CT evaluations

RATIONALE AND OBJECTIVES

To evaluate multidetector computed tomography (MDCT) for detecting the early changes and dynamic evolution of acute mesenteric ischemia (AMI) induced by the ligation of superior mesenteric vein (SMV) in an experimental porcine model.

MATERIALS AND METHODS

Twelve pigs were randomly assigned to three experimental groups, and one control group with three pigs in each group. After laparotomy, the SMV was separated and ligated in nine pigs and separated without ligation in three controls. MDCT pre- and postcontrast with arterial, venous, and delayed phase scans, and CT angiography reconstructions of mesenteric vessels were carried out at preoperation, 6 hours, 12 hours, and 18 hours after ligation. The findings of mesenteric vessels, bowel, abdominal cavity at pre- and postoperation, and dynamic evolution were correlated with pathology.

RESULTS

AMI-induced pathological changes were identified in all nine experimental pigs. MDCT angiography clearly delineated main trunk of the SMV, peripheral major and minor tributaries up to brushy vasa recta, and the location and shape of ligations. The early ischemic findings were bowel wall thickening, mesenteric edema, ascites, and pronounced bowel enhancement. Superior mesenteric artery and its major branches appeared spasm with poor filling and delayed and prolonged visualization. SMV and its tributaries were poorly delineated with delayed opacification. We also saw thinning of bowel wall, dilatating bowel with fluid, aggravating mesenteric edema and ascites, and poor enhanced bowel over time.

CONCLUSION

MDCT detects early changes of mesenteric ischemia and its evolution after ligation of porcine SMV, and may find application in early diagnosis of human venous occlusive AMI.

Value of multislice computed tomography in the diagnosis of acute mesenteric ischemia

OBJECTIVE

To define the value of multislice computed tomography (CT) in the diagnosis of acute mesenteric ischemia (AMI).

MATERIALS AND METHODS

Two hundred patients (age range: 20-92 years) who were referred to the emergency CT department with a clinical suspicion of AMI were prospectively included in the study. CT examinations were performed with a multislice (16) CT scanner and the protocol included pre-contrast, arterial and venous phase acquisitions. Images were evaluated by using multiplanar reconstruction, maximum intensity projection and volume-rendering techniques at the CT workstation.

RESULTS

Ninety-four patients (47%) underwent surgery for AMI or for other causes of acute abdominal pain. One hundred-six patients (53%) were followed conservatively according to clinical, radiologic and laboratory findings. Of the 94 patients who underwent surgery, 49 (25%) were found to have AMI. All of these 49 patients with a proven AMI diagnosis were diagnosed with CT. In the other 45 patients who underwent surgery, CT findings were negative for AMI. None of the patients, who were followed conservatively, were eventually diagnosed as having AMI except 1 patient. This patient was unfit for surgery although his clinical and radiologic findings were consistent with AMI and died in 3 days. The sensitivity and specificity values of CT for the detection of AMI were calculated to be 100% for each.

CONCLUSIONS

Multislice CT is an effective imaging technique for the diagnosis of AMI with excellent sensitivity and specificity values.

Small bowel vascular disorders from arterial etiology and impaired venous drainage

Intestinal ischemia of the small bowel represents an important diagnostic question to answer in an emergency. Although some findings could be appreciated with basic imaging methods, the MDCT as a modern noninvasive imaging method could be effective in evaluating intestinal disease caused by superior mesenteric artery or vein occlusion and making a diagnosis of ischemia from low-flow states. Looking at the features of the parietal layers with knowledge of the pathologic mechanism underlying the changes from the "normality" could be helpful in making a correct, prompt, and effective diagnosis of intestinal ischemia or disease from impaired venous drainage.

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.

Multidetector CT angiography in the diagnosis of mesenteric ischemia

Multidetector CT is an ideal tool for the diagnosis of acute and chronic mesenteric ischemia. Advanced CT scanners and expertise in three-dimensional imaging are becoming increasingly widespread, opening the door to new opportunities and challenges in the evaluation of patients suspected of having mesenteric ischemia. This article reviews contrast administration and image acquisition protocols, the anatomy of the mesenteric vasculature, the etiology of acute and chronic mesenteric ischemia, and CT findings diagnostic for these conditions.

Enhanced CT perfusion cut-off sign in midgut volvulus

We present a case of malrotation with midgut volvulus in an infant in which we discovered a unique CT sign called the perfusion cut-off sign. We hope this case will help establish this crucial diagnosis in other cases.

Acute small bowel ischemia: CT imaging findings

Small bowel ischemia is a disorder related to a variety of conditions resulting in interruption or reduction of the blood supply of the small intestine. It may present with various clinical and radiologic manifestations, and ranges pathologically from localized transient ischemia to catastrophic necrosis of the intestinal tract. The primary causes of insufficient blood flow to the small intestine are various and include thromboembolism (50% of cases), nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) can demonstrate changes because of ischemic bowel accurately, may be helpful in determining the primary cause of ischemia, and can demonstrate important coexistent findings or complications. However, common CT findings in acute small bowel ischemia are not specific and, therefore, it is often a combination of clinical, laboratory and radiologic signs that may lead to a correct diagnosis. Understanding the pathogenesis of various conditions leading to mesenteric ischemia and being familiar with the spectrum of diagnostic CT signs may help the radiologist recognize ischemic small bowel disease and avoid delayed diagnosis. The aim of this article is to provide a review of the pathogenesis and various causes of acute small bowel ischemia and to demonstrate the contribution of CT in the diagnosis of this complex disease.

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.

Radiologic diagnosis and treatment of gastrointestinal hemorrhage and ischemia

Major breakthroughs in catheter, guidewire, and other angiographic equipment currently allow interventional radiologists to diagnose massive life-threatening upper and lower GI hemorrhage and to stop the bleeding safely and effectively using superselective catheterization and microcoil embolization. Similarly, the interventional radiologist can treat acute intestinal ischemia safely and effectively with selective catheterization and papaverine administration and treat chronic mesenteric ischemia by percutaneous angioplasty and stent placement. A multidisciplinary approach, including the gastroenterologist, radiologist, and surgeon, is critical in managing GI bleeding and intestinal ischemia, particularly in patients at high risk or presenting as diagnostic dilemmas.

Ischaemic jejunal stenosis complicating portal and mesenteric vein thrombosis: a report of two cases

A major complication of portal and mesenteric vein thrombosis is acute bowel ischaemia resulting in infarction and requiring immediate resection of the involved segment. Sufficient collaterals can prevent acute haemorrhagic infarction, but bowel stenosis due to chronic ischaemia may develop. We report two cases of ischaemic jejunal stenosis occurring 4 weeks after successful treatment of portal and mesenteric vein thrombosis. Diagnosis of high-grade segmental stenosis of the jejunum was established by contrast medium radiography of the gastrointestinal tract. After laparotomy and resection of the stenosed jejunal segment, both patients recovered well from the operation and were released from hospital. Follow-up examinations revealed an unremarkable state of health. Ischaemic bowel stenosis should be considered in patients with recurring abdominal pain after mesenteric and portal vein thrombosis. A close follow-up of every patient after treatment for mesenteric and portal vein thrombosis should be carried out to ensure early diagnosis of this complication.

Mesenteric Vascular Disease

The clinical presentation of mesenteric ischemia depends on the site, grade, and cause of vascular obstruction; the degree of collateralization; and the stage of disease. Patients in the early stages of ischemia typically have abdominal pain out of context with an unimpressive abdominal examination. It is during this stage that medical and endovascular techniques can be most effective. After signs of peritonitis are present (signaling bowel infarction), surgical exploration and bowel resection are necessary. Chronic mesenteric ischemia induced by stenotic arteriosclerosis should be treated with percutaneous transluminal angioplasty and stenting (PTAS). Chronic mesenteric arterial occlusions are better handled with bypass surgery. Acute embolic or thrombotic ischemia is surgically treated after medical resuscitation. Endovascular techniques may be applicable in selected patients (usually in those with subacute symptoms), but thrombolytic therapy should be avoided if intestinal infarction is suspected. Non-occlusive mesenteric ischemia requires a rapid correction of the predisposing hypotension or sepsis followed by papaverine infusion into the superior mesenteric artery. Celiac artery compression syndrome requiring treatment is best treated with surgical release of the median arcuate ligament; PTAS should not be performed. Mesenteric venous occlusion should be treated with anticoagulation. Surgical exploration and bowel resection is necessary in patients presenting with acute signs and symptoms, reserving thrombolytic therapy for early, mildly symptomatic, thromboses in whom there is no contraindication to thrombolysis.

A retrospective study of diagnosis and management of mesenteric vein thrombosis

BACKGROUND

Mesenteric vein thrombosis (MVT) is an uncommon type of intestinal ischemia associated with significant mortality and morbidity because of its delay in diagnosis.

METHODS

A retrospective analysis of 9 patients treated surgically for MVT during 1982 to 1997 was performed.

RESULTS

Nine patients underwent surgical therapy for intestinal ischemia due to MVT. The most common presenting symptom was abdominal pain with bloody diarrhea in 3 patients; preoperative diagnosis of MVT was suspected in 2. Radiologic tests included plain roentgenograms, computed axial tomography, and ultrasound. Time to surgery ranged from 3 hours to 7 days after admission. All patients underwent resection of infarcted bowel with primary anastomosis and immediate postoperative anticoagulation. No patient underwent a second-look operation. The postoperative morbidity and mortality rates were 55% and 11%, respectively.

CONCLUSION

Diagnosis of intestinal ischemia from MVT is often delayed, and strong clinical suspicion and aggressive treatment are necessary in its management.

Mesenteric vascular occlusion resulting in intestinal necrosis in children

PURPOSE

The records of 4 patients who had necrotic bowel secondary to acute mesenteric vascular occlusion affecting various levels of mesenteric vasculature were reviewed to determine the clinical manifestations, diagnostic investigations, predisposing factors, complications, and outcome of mesenteric vascular thrombosis in children.

METHODS

The medical records of the patients (3 boys, 1 girl) treated between 1981 and 1996, inclusive, for bowel infarction secondary to mesenteric vascular thrombosis, were reviewed with regard to signs and symptoms, laboratory tests, radiological investigations, surgical findings, histopathologic examinations, and outcome.

RESULTS

The ages of the patients ranged between 1 and 14 years with a mean age of 8.2 years. Initial symptoms, present in all patients, were abdominal pain, abdominal distension, and tenderness. Laboratory and radiological findings including abdominal radiographs and abdominal ultrasonography were nondiagnostic. Selective superior mesenteric angiography showed complete obliteration of the superior mesenteric artery with absence of venous return in 1 case. Three patients with massive intestinal necrosis died of multiorgan failure or the complications of short bowel syndrome. Histological examination of the resected intestinal segments showed the typical findings of polyarteritis nodosa in 2 patients. One patient had a previous history of right femoral vein thrombosis, whereas 1 patient had no known underlying disorders predisposing vascular thrombosis.

CONCLUSIONS

Mesenteric vascular occlusion is a rare but serious disease leading to death in children. The patients present with similar clinical signs, most frequent and important are acute abdominal pain, vomiting, and distension. Mesenteric vascular occlusion is a rare cause of acute abdomen in childhood, which requires urgent diagnosis and intervention. In suspected mesenteric vascular insufficiency, angiography should be performed followed by intraarterial thrombolytic infusion therapy in selected cases. When intestinal infarction is suspected, immediate surgical resection of compromised bowel is necessary with appropriate postoperative anticoagulation or treatment of any underlying disease.

Radiologic features of vasculitis involving the gastrointestinal tract

Vasculitides can cause local or diffuse pathologic changes in the gastrointestinal tract, resulting in nonspecific paralytic ileus, mesenteric ischemia, submucosal edema and hemorrhage, or bowel perforation or stricture. The extent and clinical course of disease depend on the size and location of the affected vessel and the histologic characteristics of the lesion. Vasculitis may primarily involve large vessels (eg, giant cell arteritis, Takayasu arteritis), medium-sized vessels (eg, polyarteritis nodosa, Kawasaki disease, primary granulomatous central nervous system vasculitis), or small vessels (eg, Wegener granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, Henoch-Schönlein syndrome, systemic lupus erythematosus, rheumatoid vasculitis, Behçet syndrome). Radiologic findings in various types of vasculitis often overlap considerably and therefore have limited value in making a specific diagnosis. Nevertheless, the possibility of vasculitis should be considered whenever mesenteric ischemic changes occur in young patients, are noted at unusual sites (eg, stomach, duodenum, rectum), have a tendency to concomitantly involve the small and large intestine, and are associated with genitourinary involvement. Knowledge of systemic clinical manifestations in affected patients may suggest and even help establish the specific diagnosis.

CT and MR imaging findings of bowel ischemia from various primary causes

Ischemic bowel disease represents a broad spectrum of diseases with various clinical and radiologic manifestations, which range from localized transient ischemia to catastrophic necrosis of the gastrointestinal tract. The primary causes of insufficient blood flow to the intestine are diverse and include thromboembolism, nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) or magnetic resonance (MR) imaging can demonstrate the ischemic bowel segment and may be helpful in determining the primary cause. The CT and MR imaging findings include bowel wall thickening with or without the target sign, intramural pneumatosis, mesenteric or portal venous gas, and mesenteric arterial or venous thromboembolism. Other CT findings include engorgement of mesenteric veins and mesenteric edema, lack of bowel wall enhancement, increased enhancement of the thickened bowel wall, bowel obstruction, and infarction of other abdominal organs. However, regardless of the primary cause, the imaging findings of bowel ischemia are similar. Furthermore, the bowel changes simulate inflammatory or neoplastic conditions. Understanding the pathogenesis of various conditions leading to mesenteric ischemia helps the radiologist recognize ischemic bowel disease and avoid delayed diagnosis, unnecessary surgery, or less than optimal management.

Intestinal (mesenteric) vasculopathy. I. Acute superior mesenteric arteriopathy and venopathy

Intestinal vasculopathy is not rare, comprising about 1 per 1000 hospital admissions. Primary mesenteric vasculopathy causes cardiovascular disease, whereas secondary mesenteric ischemia causes extrinsic vascular compression or vascular trauma. Acute superior mesenteric arteriopathy is caused by a mesenteric embolus, thrombus, or vasospasm (i.e., nonocclusive vasculopathy). Acute superior mesenteric venopathy is caused by a thrombus, which is often associated with a hypercoagulopathy. The clinical presentation of both diseases is often subtle and nonspecific at an early stage and becomes overt and specific only when advanced and severe, when ischemia progresses to necrosis. The mortality of acute superior mesenteric arteriopathy is still very high, whereas superior mesenteric venopathy is less rapidly progressive and has a lower, but still significant, mortality. Early diagnosis and aggressive therapy significantly reduces the mortality of these life-threatening diseases.

The value of unenhanced CT in the diagnosis of acute appendicitis

OBJECTIVE

To establish the accuracy of unenhanced CT in the preoperative diagnosis of acute appendicitis.

DESIGN

Accuracy study, prospective and blinded.

SETTING

The University Hospital.

PARTICIPANTS

52 patients with clinical and laboratorial manifestations of acute appendicitis. CT diagnosis was made by: presence of an abnormal appendix, appendiceal calculi with pericecal phlegmon or alterations in the pericecal appendicular site and absence of signs that may lead to other diagnosis.

MAIN OUTCOME MEASURES

Overall accuracy, comparing the tomographic aspects with the intra-operative findings and pathological reports ("gold standard").

RESULTS

Acute appendicitis was confirmed in 44 cases. Efficacy was 92%, sensitivity was 91%, specificity was 100%, positive predictive value was 100% and negative predictive value was 67%.

CONCLUSIONS

Unenhanced CT presents a similar overall accuracy to that reported by other authors who studied enhanced CT diagnosis of acute appendicitis.

Mesenteric ischaemia: a multidisciplinary approach

Mesenteric ischaemia may result from a wide range of pathological processes, each possessing unique clinical features, diagnostic difficulties, management strategies and outcome. Regardless of aetiology, prognosis depends crucially on rapid diagnosis and institution of treatment to prevent, or at least to minimize, bowel infarction. Progress in understanding the pathophysiology of mesenteric ischaemia has led to novel methods of treatment, so that in some circumstances therapy may be purely medical. More often surgery is required and is frequently life saving. Percutaneous transcatheter techniques are increasingly employed in both diagnosis and treatment. Close cooperation between radiologists, physicians and surgeons is therefore necessary if clinical outcome is to be optimized. This paper reviews the modern interdisciplinary management of mesenteric ischaemia in the light of recent advances.

Acute occlusive ischemia of the rat intestine: early detection by MR imaging with polylysine-Gd-DTPA enhancement

The purpose of this study was to assess the potential role of MR imaging with polylysine-Gd-DTPA enhancement in the early detection of acute occlusive intestinal ischemia in a rat model. After devascularization of the distal ileum in 12 rats, T2-weighted fast spin-echo MR images were acquired, followed by T1-weighted images before and after IV administration of 0.1 mmol/kg polylysine-Gd-DTPA. The signal intensity of the ischemic intestine did not differ significantly from that of the normal intestine before the administration of the contrast material. No mucosal or submucosal edema or hemorrhage was found in the ischemic intestine at histologic examination. After the administration of polylysine-Gd-DTPA, the ischemic intestine lacked enhancement and its signal intensity was significantly lower than that of the normal intestine. MR imaging with polylysine-Gd-DTPA enhancement can detect acute occlusive ischemia of the rat intestine at an early stage.

CT in the early detection of strangulation in intestinal obstruction

The role of CT in evaluating the gastrointestinal tract has increased recently because CT demonstrates pathological conditions involving the bowels, mesenteric vessels, and peritoneal cavity well. In patients who have an intestinal obstruction, the observation of both bowel loop configuration and mesenteric vessels on CT is the key to identifying the site and cause of obstruction and determining the absence or presence of intestinal strangulation. Although many clinical and radiological findings reported in the literature are not seen in the early stages of intestinal strangulation, CT might assist in its early detection. This article reviews the clinical, pathophysiological, and radiological aspects of strangulating obstruction with emphasis on the role of CT in its early diagnosis.

Computed tomography in acute small bowel obstruction

The abdominal computed tomograms of 28 patients with a clinical diagnosis of acute small bowel obstruction were reviewed. Computed tomography accurately identified the presence, severity and level of obstruction. Signs such as angulated bowel loops and adjacent streaks within the mesentery at points of luminal calibre change were recognized in 69% of cases with adhesive obstruction. Computed tomography may reveal non-adhesive causes and is the modality of choice for investigating patients with higher grades of bowel obstruction where early surgical intervention is contemplated.