|Year : 2020 | Volume
| Issue : 4 | Page : 395-399
Role of multislice computed tomography angiography in the diagnosis of clinically suspected acute mesenteric ischemia
Basma F. M G. Elrab1, Afaf A. El-Qader Hasan Elmamlok1, Abo-Elhassan H Mohammed1, Ahmed K Elminshawy2
1 Department of Radio-Diagnosis, Faculty of Medicine, Assiut University Assiut University, Assiut, Egypt
2 Professor of Cardio-Thoracic Surgery, Assiut University Assiut University, Assiut, Egypt
|Date of Submission||13-Jan-2020|
|Date of Decision||19-Feb-2020|
|Date of Acceptance||25-Feb-2020|
|Date of Web Publication||20-Nov-2020|
Basma F. M G. Elrab
Department of Radio-diagnosis, Faculty of Medicine, Assiut University Hospitals, Assiut University, Assiut
Source of Support: None, Conflict of Interest: None
The study aims to determine the accuracy of computed tomography angiography (CTA) in the diagnosis of cases of acute mesenteric ischemia (AMI).
Patients and methods
Fifty patients clinically suspected to have AMI were included and evaluated by multislice computed tomography (MSCT) abdominal angiography to detect the sensitivity, specificity, and diagnostic accuracy of the procedure.
The final diagnosis confirmed mesenteric vascular occlusion (MVO) in 29 (58%) patients; of the 29 patients with MVO, 10 (34.5%) patients had arterial occlusion and 19 (65.5%) had venous occlusion. MSCT showed MVO in 28 (56%) patients; of the 28 patients with MVO, 10 (35.7%) patients had arterial occlusion and 18 (64.3%) patients had venous occlusion. As regards the 28 patients diagnosed by MSCT as MVO, the final diagnosis approved MVO in 27 of them while one patient was negative. CTA showed a sensitivity of 93.1%, specificity of 95.24%, and an overall accuracy of 94%.
CTA is an accurate tool that helps in the diagnosis of bowel ischemia with high accuracy in diagnosis. This supports the role of CTA as the ideal first-step imaging procedure in cases suspected to have AMI.
Keywords: abdominal angina, mesenteric ischemia, multislice computed tomography angiography
|How to cite this article:|
G. Elrab BF, Hasan Elmamlok AA, Mohammed AEH, Elminshawy AK. Role of multislice computed tomography angiography in the diagnosis of clinically suspected acute mesenteric ischemia. J Curr Med Res Pract 2020;5:395-9
|How to cite this URL:|
G. Elrab BF, Hasan Elmamlok AA, Mohammed AEH, Elminshawy AK. Role of multislice computed tomography angiography in the diagnosis of clinically suspected acute mesenteric ischemia. J Curr Med Res Pract [serial online] 2020 [cited 2020 Dec 1];5:395-9. Available from: http://www.jcmrp.eg.net/text.asp?2020/5/4/395/301048
| Background|| |
Acute mesenteric ischemia (AMI) is a life-threatening disease having a high rate of mortality,. Although AMI represents less than 0.001 hospital admissions, its mortality rate is high reaching up to 90%. Arterial embolism is the most common cause of AMI; the second common cause is arterial thrombosis, followed by nonocclusive ischemia, and lastly venous thrombosis.
Accurate diagnosis and rapid successful treatment of AMI are the cornerstones to improve its outcome and the delayed diagnosis contributes to the continued high mortality rate.
However, the variable presentations and different causes of AMI make its diagnosis a major challenge,. Patients' presentations ordinarily are vague abdominal symptoms and nonspecific laboratory findings, leading to a delay in the diagnosis5],,,,,. Therefore, imaging diagnosis has considered one of the most decisive components in suspected AMI diagnostic workup,.
Recently, advanced modalities are raising the role of computed tomography angiography (CTA) to be the modality of choice in suspected cases with AMI. CTA is a fast and noninvasive diagnostic modality for assessing both intestinal vascularity and loops,. CTA allows earlier diagnosis and differentiation between occlusive and nonocclusive causes, which are important to effective therapeutic management,. So, a combination of assessment of both vascular and bowel findings resulted in better diagnostic accuracy,,,.
Knowledge of the alternative diagnoses in cases diagnosed as non-AMI have a very important role in proper patient care. CTA allows the diagnosis of variable acute alternative diagnoses that help in improving the clinical outcomes of those patients.
| Aim|| |
Our study aims to determine the diagnostic accuracy of CTA in the diagnosis of AMI.
| Patients and Methods|| |
Our study performance was between May 2018 and May 2019 on 50 consecutive patients with clinical suspicion of AMI. They were referred from the emergency department and the outpatient clinics of general surgery and general medicine departments of Assiut University Hospitals.
High clinical suspicion of AMI based on the evaluation of physicians during 48 h of acute manifestation.
The clinical suspicion of mesenteric ischemia was based on the following findings: pain disproportionate to the clinical signs, postprandial abdominal pain, loss of weight, and history of previous abdominal angina, history of previous mesenteric ischemia, atrial fibrillation, severe vascular disease, and hypercoagulable states.
Those patients with known renal impairment or allergic to iodinated contrast media were excluded.
The study protocol was approved and monitored by the Medical Ethics Committee, Assiut Faculty of Medicine and written consent was taken from all patients (IRB: 17100956). Patients signed an informed consent.
Protocol of computed tomography angiography
Multislice computed tomography (MSCT) imaging was performed using either 16- detector (GE [bright speed, GE healthcare 16 slice, Boston, USA]), 64-detector (Toshiba [Aquilion 64, Toshiba Medical Systems, Nasu, Japan]), or 128-detector (Siemens [SOMATOM 128 detectors, Siemens, Forchheim, Germany]) MSCT scanners for CTA in the arterial and portovenous phases with a tube voltage equal 120 kV and automated range of effective tube current between 100 and 400 mA. Nonionic contrast material was used with at a dose of 100–120 ml according to the body built (1.5 ml/kg body weight) intravenously at a rate of 3–4 ml/s by an automatic injector, through an 18-G antecubital intravenous line. The cuts were taken from the xiphoid process down to the symphysis pubis with a slice thickness of 0.5 mm.
Arterial phase imaging was acquired using bolus tracking of the contrast material at the abdominal aorta to determine the arrival of the bolus of contrast material. The portal phase was imaged either 70–80 s postinjection or 50–60 s after bolus tracking. The venous phase was imaged either 100-s postinjection or 80 s after bolus tracking.
Multislice computed tomography postprocessing techniques
Data were acquired in 0.5 mm slice thickness and intervals, and images were reconstructed and viewed on a workstation (via GE workstation, Vitrea, Siemens Syngo), which provide multiplanar 'axial, sagittal, oblique and coronal' reformatted and volume rendering images including the small and large bowel. Maximum intensity projection, three-dimensional volume rendering, multiplanar reformatted images, and curved planar reconstruction were done from the arterial phase volume.
MSCT images were analyzed to diagnose AMI depending on vascular MSCT findings such as arterial occlusion 'embolism or thrombus,' stenosis, arterial dissection, or mesenteric venous thrombosis. Other MSCT findings were analyzed to detect abnormal bowel wall thickening of more than 3 mm in noncollapsed bowel, mucosal attenuation in precontrast scans, mucosal enhancement pattern in postcontrast CT scans, mesenteric fat stranding, free fluid collection, air density within the bowel wall, superior mesenteric vein, or portal vein. The impressed MSCT diagnosis for each patient was compared with the reported final clinical diagnosis.
The final clinical diagnosis
The close follow-up of the patients to determine the final clinical diagnosis was based on emergency department evaluation, laboratory, surgical, pathological, and follow-up imaging reports. The determined final clinical diagnosis for each patient was used as the standard reference including patients with delayed diagnoses and interventions.
Data was collected and analyzed using the Statistical Package for the Social Sciences (version 20; IBM, Armonk, New York, USA). Continuous data were expressed in the form of mean ± SD or median (range), while nominal data were expressed in the form of frequency (percentage). c2 test was used to compare the nominal data and the Student's t test was used to compare continuous variables. Diagnostic performance of CTA including sensitivity, specificity, predictive values, and accuracy were calculated. P value was considered significant if less than 0.05.
| Results|| |
In this study, 50 patients with clinical suspicion of AMI have been examined using CTA including 34 (68%) men and 16 (32%) women. The mean ± SD age of the examined patients was 50.86 ± 12.74 years with a range between 18 and 75 years.
As regards the risk factors for AMI in the studied patients, liver cirrhosis (18%) and atrial fibrillation (12%) were the most frequent risk factors, followed by previous intestinal ischemia (6%) and malignant diseases (4%).
Acute abdomen was the most frequent clinical presentation in 20 (40%) patients. Constipation, repeated vomiting, gastrointestinal bleeding, and fever were present in 14 (28%), seven (14%), six (12%), and two (4%) patients, respectively.
Among the studied patients, MSCT showed mesenteric vascular occlusion (MVO) in 28 (56%) patients, while in the remaining 22 (44%) patients, non-MVO has been encountered. Of the 28 patients with MVO, 10 (35.7%) had arterial occlusion and 18 (64.3%) had venous occlusion [Figure 1], [Figure 2], [Figure 3].
|Figure 1: (a) Axial CT portal phase shows thrombosis of SMV 'arrows;' (b) axial CT portal phase showing dilated bowel loops with thickened edematous mildly enhancing walls; (c) coronal reconstructed CT image portal phase shows SMV thrombosis extending to its tributaries 'arrows;' (d) coronal CT arterial phase showing normal SMA. CT, computed tomography; SMA, superior mesenteric artery.|
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|Figure 2: (a) Axial CT image of the arterial phase shows thrombosed SMA 'arrows;' (b) sagittal reformatted MIP CT image of the thrombosed SMA 'arrows;' (c and d) axial CT images showing dilated loops with thickened nonenhanced walls and pneumointestinalis. CT, computed tomography; MIP, maximum intensity projection; SMA, superior mesenteric artery.|
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|Figure 3: (a) Coronal reformatted MIP CT image shows normal SMA 'arrows;'' (b) axial CT image portal phase showing normal SMV 'arrowed;' (c and d) coronal and axial CT images at a delayed phase shows left extrarenal contrast leakage due to ruptured left renal calyx. CT, computed tomography; MIP, maximum intensity projection; SMA, superior mesenteric artery.|
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Among the studied patients, the final diagnosis showed MVO in 29 (58%) patients while in the remaining 21 (42%) patients, non-MVO has been encountered.
Of the 29 patients with MVO, 10 (34.5%) had arterial occlusion and 19 (65.5%) had venous occlusion.
Of the 28 patients diagnosed by MSCT as MVO, the final diagnosis confirmed MVO in 27 of them while in one patient there was no MVO. Of the 22 patients diagnosed by MSCT such as non-MVO, the final diagnosis confirmed non-MVO in 20 of them while in two patients there was MVO [Table 1].
|Table 1: Cross-tabulation between final and multislice computed tomography diagnosis of the studied patients|
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It was noticed that CTA had 93.1% sensitivity and 95.24% specificity for the prediction of MVO in patients with acute abdomen [Table 2].
|Table 2: Accuracy of computed tomography angiography in diagnosing mesenteric vascular occlusion|
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| Discussion|| |
Mesenteric ischemia is a rare disease affecting the small and large intestine resulting from reduced blood flow of the intestine. The disease has a high death rate in an acute stage in spite of advances in management options,,,.
The causes of ischemia include arterial embolism or thrombosis, venous thrombosis, or vasoconstriction of blood vessels. There is increased prevalence in the older population and nonspecific clinical symptoms and signs leading to delayed diagnosis causing the high death rate. Mostly mesenteric ischemia is due to an acute insult that leads to the diminished blood supply to the intestine.
AMI is most commonly caused by acute embolism to the superior mesenteric artery (SMA), which accounts for about half of all episodes, then acute thrombosis of mesenteric artery mesenteric ischemia, followed by nonocclusive mesenteric ischemia and mesenteric and portal venous thrombosis, the least common cause.
CTA can be helpful in detecting the grades of arterial stenosis and in differentiating between patients who would benefit from angiographic management and those who need surgical intervention.
Abdominal MSCT imaging also helps in the assessment of the entire gastrointestinal and genitourinary tract, excluding other differential diagnoses as causes of acute abdominal pain including pancreatitis, appendicitis, cholelithiasis, nephrolithiasis, and diverticulitis.
The etiology of mesenteric ischemia determines the outcome of the patient and if thromboembolic occlusion of the SMA is the cause of AMI fatality, occurring in up to 95% of cases. It is important to detect intestinal ischemia before infarction of intestinal wall results to get better outcomes.
Our study confirmed that AMI is mainly an abdominal emergency condition in the older patients. We found only one (0.03%) young patient aged 32 years old with ischemia, among the 29 patients with a proven diagnosis of AMI. This is in keeping with Henes et al. who stated that there is a significant increase in the prevalence of AMI in patients of age more than 35 years.
The major risk factors in patients with AMI in our study were liver cirrhosis, and atrial fibrillation followed by previous intestinal ischemia and malignant diseases. Other risk factors included old age and hypovolemia. This matched with Hemat et al. who stated that advanced age, atherosclerosis, recent MI, arrhythmias, valvular disease, CHF hypovolemia, and intra-abdominal malignancy are the major risk factors for AMI.
Abdominal pain disproportionate to physical signs and examination is the most common clinical presentations followed by constipation, repeated vomiting, and gastrointestinal bleeding. Less common presentations were fever and shock. This was going with the same findings as Owens and Ronan-Bentle which stated that AMI is mostly presented by abdominal pain disproportionate to physical examination with a history of cardiovascular affection. Patients may have variable other presentations including projectile vomiting, bloody diarrhea, fever, and lastly infarction of the bowel wall that makes the patient vitally unstable.
Our study showed that 10 (34.5%) patients from those with MVO had SMA occlusion; six patients had complete occlusion of the artery while four patients had partial occlusion.
The other 19 (65.5%) patients with MVO had superior mesenteric vein thrombosis. Twelve patients from those with SMV thrombosis had also portal vein thrombosis.
On the other side, Fidelman et al. reported a higher incidence of AMI due to SMA embolism or thrombosis in comparison to mesenteric venous thrombosis. This may be contributed to our sample size and the increased incidence of liver diseases in Egypt.
On comparing CTA findings with endoscopic, surgical, and follow up of the patients, we found that CTA has accurately diagnosed AMI in 27/29 patients and was false negative in two patients, resulting in a sensitivity of 93.1%. The two false-negative cases were diagnosed as minor branch AMI and the other as mesenteric ischemia of the nonocclusive type.
CTA correctly excluded AMI in 20/21 patients and was false positive in one patient, resulting in a specificity of 95.24%. The accuracy of CTA in the diagnosis of mesenteric ischemia was 94%. That was in keeping with Kanasaki et al. which stated that the diagnostic accuracy of CTA for detection of AMI is high with a sensitivity of 64–96% and a specificity of 92–100%.
In another study, Menke et al. showed a sensitivity of 93.3% and specificity of 95.9% contrast-enhanced MSCT in the detection of primary AMI.
| Conclusion|| |
In conclusion, CTA is an accurate tool that allows for the detection of bowel ischemia with high diagnostic performance. This highly supports the role of CTA as the ideal first-step imaging procedure to confirm or rule out AMI in cases suspected to have the disease.
Authors' contributions: Afaf A. El-Qader Hasan Elmamlok and Abo-Elhassan H. Mohammed suggested and developed the research idea and reviewed the literature. Afaf A. El-Qader Hasan Elmamlok, Abo-Elhassan H. Mohammed, and Basma F.M.G. Elrab were responsible for data collection and analysis, writing and revising the manuscript, performed statistical analysis, prepared cases, and performed the required measurements, figures and tables. Afaf A. El-Qader Hasan Elmamlok and Abo-Elhassan H. Mohammed were responsible for reporting the cases of MSCT and Afaf A. El-Qader Hasan Elmamlok, Abo-Elhassan H. Mohammed, and Basma F.M.G. Elrab compared it with the final clinical diagnosis. All authors have a major contribution in preparing and editing the manuscript. All authors read and approved the final manuscript.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Ottinger LW. Mesenteric ischemia. N
Engl J Med 1982; 307:535–537.
Ruotolo RA, Evans SRT. Mesenteric ischemia in the elderly. Clin Geriatr Med 1999; 15:527–557.
Herbert GS, Steele SR. Acute and chronic mesenteric ischemia. Surg Clin North Am 2007; 87:1115–1134.
Hirsch AT, Haskal ZJ, Hertzer NR, Bakal CW, Creager MA, Halperin JL, et al
. ACC/AHA 2005 practice guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): a collaborative report from the american association for vascular surgery/society for vascular sur. Circulation 2006; 113:e463–e654.
Cudnik MT, Darbha S, Jones J, Macedo J, Stockton SW, Hiestand BC. The diagnosis of acute mesenteric ischemia: A systematic review and meta-analysis. Acad Emerg Med 2013; 20:1087–1100.
Paterno F, Longo WE. The etiology and pathogenesis of vascular disorders of the intestine. Radiol Clin North Am 2008; 46:877–885.
Yasuhara H. Acute mesenteric ischemia: the challenge of gastroenterology. Surg Today 2005; 35:185–195.
Martinez JP, Hogan GJ. Mesenteric ischemia. Emerg Med Clin North Am 2004; 22:909–928.
Demir IE, Ceyhan GO, Friess H. Beyond lactate: is there a role for serum lactate measurement in diagnosing acute mesenteric ischemia?. Dig Surg 2012; 29:226–235.
Acosta S, Nilsson T. Current status on plasma biomarkers for acute mesenteric ischemia. J Thromb Thrombolysis 2012; 33:355–361.
Oliva IB, Davarpanah AH, Rybicki FJ, Desjardins B, Flamm SD, Francois CJ, et al
. ACR Appropriateness Criteria® imaging of mesenteric ischemia. Abdom Imaging 2013; 38:714–719.
Horton KM, Fishman EK. Multidetector CT angiography in the diagnosis of mesenteric ischemia. Radiol Clin North Am 2007; 45:275–288.
Kirkpatrick IDC, Kroeker MA, Greenberg HM. Biphasic CT with mesenteric CT angiography in the evaluation of acute mesenteric ischemia: initial experience. Radiology 2003; 229:91–98.
Reginelli A, Iacobellis F, Berritto D, Gagliardi G, Di Grezia G, Rossi M, et al
. Mesenteric ischemia: the importance of differential diagnosis for the surgeon. BMC Surg 2013; 13:S51.
Sise MJ. Acute mesenteric ischemia. Surg Clin 2014; 94:165–181.
Taourel PG, Deneuville M, Pradel JA, Régent D, Bruel JM. Acute mesenteric ischemia: diagnosis with contrast-enhanced CT. Radiology 1996; 199:632–636.
Aschoff AJ, Stuber G, Becker BW, Hoffmann MHK, Schmitz BL, Schelzig H, et al
. Evaluation of acute mesenteric ischemia: accuracy of biphasic mesenteric multi-detector CT angiography. Abdom Imaging 2009; 34:345–357.
Ofer A, Abadi S, Nitecki S, Karram T, Kogan I, Leiderman M, et al
. Multidetector CT angiography in the evaluation of acute mesenteric ischemia. Eur Radiol 2009; 19:24–30.
Henes FO, Pickhardt PJ, Herzyk A, Lee SJ, Motosugi U, Derlin T, et al
. CT angiography in the setting of suspected acute mesenteric ischemia: prevalence of ischemic and alternative diagnoses. Abdom Radiol 2017; 42:1152–1161.
Acosta S, Wadman M, Syk I, Elmståhl S, Ekberg O. Epidemiology and prognostic factors in acute superior mesenteric artery occlusion. J Gastrointest Surg 2010; 14:628–635.
Kassahun WT, Schulz T, Richter O, Hauss J. Unchanged high mortality rates from acute occlusive intestinal ischemia: six year review. Langenbeck's Arch Surg 2008; 393:163–171.
Schoots IG, Koffeman GI, Legemate DA, Levi M, Van Gulik TM. Systematic review of survival after acute mesenteric ischaemia according to disease aetiology. Br J Surg 2004; 91:17–27.
Ginsburg M, Obara P, Lambert DL, Hanley M, Steigner ML, Camacho MA, et al
. ACR appropriateness criteria® imaging of mesenteric ischemia. J Am Coll Radiol 2018; 15:S332–S340.
Hemat EM, Ahmed AF, Bessar MA. Multi-slice CT angiography in assessment of patients with mesenteric ischemia. J Am Sci 2016; 12:12.
Owens S, Ronan-Bentle S. What Clinical Features Lead to the Diagnosis of Acute Mesenteric Ischemia?. In: Graham A., Carlberg D. (eds) Gastrointestinal Emergencies. Springer, Cham. University of Cincinnati College of Medicine, Department of Emergency Medicine Cincinnati USA. 2019. p. 93–95.
Fidelman N, AbuRahma AF, Cash BD, Kapoor BS, Knuttinen MG, Minocha J, et al
. ACR Appropriateness Criteria® radiologic management of mesenteric ischemia. J Am Coll Radiol 2017; 14:S266–S271.
Kanasaki S, Furukawa A, Fumoto K, Hamanaka Y, Ota S, Hirose T, et al
. Acute mesenteric ischemia: multidetector CT findings and endovascular management. RadioGraphics 2018; 38:945–961.
Menke J, Larsen J. Diagnostic accuracy of multidetector CT in acute mesenteric ischemia: Systematic review and meta-analysis. In European Congress of Radiology 2012; 2012.C-1054:6–9
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2]