Pretreatment with a dual antiplatelet and anticoagulant (APAC) reduces ischemia-reperfusion injury in a mouse model of temporary middle cerebral artery occlusion-implications for neurovascular procedures.

BACKGROUND: Several neurovascular procedures require temporary occlusion of cerebral arteries, leading to ischemia of unpredictable length, occasionally causing brain infarction. Experimental models of cerebral ischemia-reperfusion injury have established that platelet adhesion and coagulation play detrimental roles in reperfusion injury following transient cerebral ischemia. Therefore, in a model of cerebral ischemia-reperfusion injury (IRI), we investigated the therapeutic potential of a dual antiplatelet and anticoagulant (APAC) heparin proteoglycan mimetic which is able to bind to vascular injury sites. METHODS: Brain ischemia was induced in mice by transient occlusion of the right middle cerebral artery for 60 min. APAC, unfractionated heparin (UFH) (both at heparin equivalent doses of 0.5 mg/kg), or vehicle was intravenously administered 10 min before or 60 min after the start of ischemia. At 24 h later, mice were scored for their neurological and motor behavior, and brain damage was quantified. RESULTS: Both APAC and UFH administered before the onset of ischemia reduced brain injury. APAC and UFH pretreated mice had better neurological and motor functions (p < 0.05 and p < 0.01, respectively) and had significantly reduced cerebral infarct sizes (p < 0.01 and p < 0.001, respectively) at 24 h after transient occlusion compared with vehicle-treated mice. Importantly, no macroscopic bleeding complications were observed in either APAC- or UFH-treated animals. However, when APAC or UFH was administered 60 min after the start of ischemia, the therapeutic effect was lost, but without hemorrhaging either. CONCLUSIONS: Pretreatment with APAC or UFH was safe and effective in reducing brain injury in a model of cerebral ischemia induced by transient middle cerebral artery occlusion. Further studies on the use of APAC to limit ischemic injury during temporary occlusion in neurovascular procedures are indicated.

Friendly Neck Anatomy Does Not Prevent Neck-Related Adverse Events After EVAR.

BACKGROUND: Life-long follow-up after endovascular aneurysm repair (EVAR) is costly and burdensome to the patient. Follow-up should be stratified based on the risk of EVAR failure. Aneurysm neck is thought to be the single most important risk factor. This study investigated neck anatomy as a predictor of neck-related adverse events after EVAR. METHODS: This retrospective single-center study included consecutive patients undergoing elective EVAR for infrarenal abdominal aortic aneurysms between 2011 and 2016 (n = 222) who were followed with yearly imaging until December 2020. Hostile neck was defined as neck length ≤15 mm, width ≥28 mm, angulation ≥60°, calcification, or thrombus ≥50% of circumference or conical neck based on preoperative computed tomography angiography. Neck-related adverse event was defined as aneurysm rupture, any neck-related reintervention or type 1a endoleak during follow-up. RESULTS: Ninety (41%) patients had hostile neck and 132 (59%) had friendly neck. There were no differences in 30-day mortality (1% vs. 1%, P = 0.78), major adverse events (20% vs. 16%, P = 0.43) or reinterventions during the hospital stay (8% vs. 4%, P = 0.20) between patients with hostile and friendly neck. Estimated survival at 1 year was 89 ± 3% for hostile neck and 95 ± 2% for friendly neck patients (P < 0.01). Five-year survival estimates were 51 ± 6% and 66 ± 4%, respectively. Aneurysm-related mortality was higher after 6 years in patients with hostile neck (P < 0.01). Twenty-four patients (11%) suffered neck-related adverse events with mean time-to-event of 3.3 ± 2.8 years; there were no differences between the groups stratified by neck anatomy. Incidentally, preoperative aneurysm diameter was found to be an independent risk factor for neck-related adverse events and aneurysm-related mortality; 53 patients (24%) had aneurysm diameter ≥70 mm, which was associated with nearly 4-fold risk of neck-related complications during the follow-up. CONCLUSIONS: Friendly neck anatomy may not protect from neck-related adverse events after EVAR in the long-term. Especially patients with large aneurysms should be followed closely.

A modified candy-plug technique to occlude false lumen in aortic dissection.

PURPOSE: Aim of this technical note article is to introduce a modified, novel way to custom create a candy-plug (CP) device to endovascularly occlude false lumen. The technique is illustrated by a patient case with significant backflow to false lumen (FL). The patient had already undergone surgical repair of the ascending aorta, aortic arch and subsequent TEVAR procedure down to the ostium of the celiac trunk because of type A aortic dissection, but the descending thoracic aorta continued to dilate due to backflow to the FL from an uncovered tear at the level of the renal arteries. MATERIALS AND METHODS: We modified a Gore Excluder 36-45 mm aortic extender (W. L. Gore & Associates, Inc. Flagstaff, USA) endoprosthesis into a CP device that was subsequently positioned under local anesthesia into the FL of the distal descending thoracic aorta. RESULTS: In 1 month control the backflow to false lumen had ceased and the aorta had decreased in diameter from 69 to 66 mm, FL from 37 to 34 mm, true lumen (TL) remained the same 32 mm. CONCLUSION: We describe a modified, effective candy-plug technique to occlude retrograde false lumen filling in aortic dissection.

Effect of different thresholds for CT perfusion volumetric analysis on estimated ischemic core and penumbral volumes.

PURPOSE: This single-center study compared three threshold settings for automated analysis of the ischemic core (IC) and penumbral volumes using computed tomographic perfusion, and their accuracy for predicting final infarct volume (FIV) in patients with anterior circulation acute ischemic stroke (AIS). METHODS: Fifty-two consecutive AIS patients undergoing mechanical thrombectomy (November 2015-March 2018) were included. Perfusion images were retrospectively analyzed using a single CT Neuro perfusion application (syngo.via 4.1, Siemens Healthcare GmbH). Three threshold values (S1-S3) were derived from another commercial package (RAPID; iSchema View) (S1), up-to-date syngo.via default values (S2), and adapted values for syngo.via from a reference study (S3). The results were compared with FIV determined by non-contrast CT. RESULTS: The median IC volume (mL) was 24.6 (interquartile range: 13.7-58.1) with S1 and 30.1 (20.1-53.1) with S2/S3. After removing the contralateral hemisphere from the analysis, the median IC volume decreased by 1.33(0-3.14) with S1 versus 9.13 (6.24-14.82) with S2/S3. The median penumbral volume (mL) was 74.52 (49.64-131.91), 77.86 (46.56-99.23), and 173.23 (125.86-200.64) for S1, S2, and S3, respectively. Limiting analysis to the affected hemisphere, the penumbral volume decreased by 1.6 (0.13-9.02), 19.29 (12.59-26.52), and 58.33 mL (45.53-74.84) for S1, S2, and S3, respectively. The correlation between IC and FIV was highest in patients with successful recanalization (n = 34, r = 0.784 for S1; r = 0.797 for S2/S3). CONCLUSION: Optimizing thresholds significantly improves the accuracy of estimated IC and penumbral volumes. Current recommended values produce diversified results. International guidelines based on larger multicenter studies should be established to support the standardization of volumetric analysis in clinical decision-making.

Quantification of Myocardial Blood Flow by Machine Learning Analysis of Modified Dual Bolus MRI Examination.

Contrast-enhanced magnetic resonance imaging (MRI) is a promising method for estimating myocardial blood flow (MBF). However, it is often affected by noise from imaging artefacts, such as dark rim artefact obscuring relevant features. Machine learning enables extracting important features from such noisy data and is increasingly applied in areas where traditional approaches are limited. In this study, we investigate the capacity of machine learning, particularly support vector machines (SVM) and random forests (RF), for estimating MBF from tissue impulse response signal in an animal model. Domestic pigs (n = 5) were subjected to contrast enhanced first pass MRI (MRI-FP) and the impulse response at different regions of the myocardium (n = 24/pig) were evaluated at rest (n = 120) and stress (n = 96). Reference MBF was then measured using positron emission tomography (PET). Since the impulse response may include artefacts, classification models based on SVM and RF were developed to discriminate noisy signal. In addition, regression models based on SVM, RF and linear regression (for comparison) were developed for estimating MBF from the impulse response at rest and stress. The classification and regression models were trained on data from 4 pigs (n = 168) and tested on 1 pig (n = 48). Models based on SVM and RF outperformed linear regression, with higher correlation (R SVM 2 = 0.81, R RF 2 = 0.74, R linear_regression 2 = 0.60; ρSVM = 0.76, ρRF = 0.76, ρlinear_regression = 0.71) and lower error (RMSESVM = 0.67 mL/g/min, RMSERF = 0.77 mL/g/min, RMSElinear_regression = 0.96 mL/g/min) for predicting MBF from MRI impulse response signal. Classifier based on SVM was optimal for detecting impulse response signals with artefacts (accuracy = 92%). Modified dual bolus MRI signal, combined with machine learning, has potential for accurately estimating MBF at rest and stress states, even from signals with dark rim artefacts. This could provide a protocol for reliable and easy estimation of MBF, although further research is needed to clinically validate the approach.

Association of Intracranial Aneurysms With Aortic Aneurysms in 125 Patients With Fusiform and 4253 Patients With Saccular Intracranial Aneurysms and Their Family Members and Population Controls.

Background Varying degrees of co-occurrence of intracranial aneurysms (IA) and aortic aneurysms (AA) have been reported. We sought to compare the risk for AA in fusiform intracranial aneurysms (fIA) and saccular intracranial aneurysms (sIA) disease and evaluate possible genetic connection between the fIA disease and AAs. Additionally, the characteristics and aneurysms of the fIA and sIA patients were compared. Methods and Results The Kuopio Intracranial Aneurysm Database includes all 4253 sIA and 125 fIA patients from its Eastern Finnish catchment population, and 13 009 matched population controls and 18 455 first-degree relatives to the IA patients were identified, and the Finnish national registers were used to identify the individuals with AA. A total of 33 fIA patients were studied using an exomic gene panel of 37 genes associated with AAs. Seventeen (14.4%) fIA patients and 48 (1.2%) sIA patients had a diagnosis of AA. Both fIA and sIA patients had AAs significantly more often than their controls (1.2% and 0.5%) or relatives (0.9% and 0.3%). In a competing risks Cox regression model, the presence of fIA was the strongest risk factor for AA (subdistribution hazard ratio 7.6, 95% CI 3.9-14.9, P<0.0005). One likely pathogenic variant in COL5A2 and 3 variants of unknown significance were identified in MYH11, COL11A1, and FBN1 in 4 fIA patients. Conclusions The prevalence of AAs is increased slightly in sIA patients and significantly in fIA patients. fIA patients are older and have more comorbid diseases than sIA patients but this alone does not explain their clinically significant AA risk.

Quantification of porcine myocardial perfusion with modified dual bolus MRI - a prospective study with a PET reference.

BACKGROUND: The reliable quantification of myocardial blood flow (MBF) with MRI, necessitates the correction of errors in arterial input function (AIF) caused by the T1 saturation effect. The aim of this study was to compare MBF determined by a traditional dual bolus method against a modified dual bolus approach and to evaluate both methods against PET in a porcine model of myocardial ischemia. METHODS: Local myocardial ischemia was induced in five pigs, which were subsequently examined with contrast enhanced MRI (gadoteric acid) and PET (O-15 water). In the determination of MBF, the initial high concentration AIF was corrected using the ratio of low and high contrast AIF areas, normalized according to the corresponding heart rates. MBF was determined from the MRI, during stress and at rest, using the dual bolus and the modified dual bolus methods in 24 segments of the myocardium (total of 240 segments, five pigs in stress and rest). Due to image artifacts and technical problems 53% of the segments had to be rejected from further analyses. These two estimates were later compared against respective rest and stress PET-based MBF measurements. RESULTS: Values of MBF were determined for 112/240 regions. Correlations for MBF between the modified dual bolus method and PET was rs = 0.84, and between the traditional dual bolus method and PET rs = 0.79. The intraclass correlation was very good (ICC = 0.85) between the modified dual bolus method and PET, but poor between the traditional dual bolus method and PET (ICC = 0.07). CONCLUSIONS: The modified dual bolus method showed a better agreement with PET than the traditional dual bolus method. The modified dual bolus method was found to be more reliable than the traditional dual bolus method, especially when there was variation in the heart rate. However, the difference between the MBF values estimated with either of the two MRI-based dual-bolus methods and those estimated with the gold-standard PET method were statistically significant.

Aneurysm Size is the Strongest Risk Factor for Intracranial Aneurysm Growth in the Eastern Finnish Population.

BACKGROUND: Saccular intracranial aneurysm (sIA) growth during follow-up is associated with high risk for subsequent rupture. Finnish patients have been suggested to have higher risk for subarachnoid hemorrhage, but follow-up studies of sIA growth in the Finnish population are scarce. OBJECTIVE: To identify the strongest risk factors for sIA growth in Eastern Finnish population by studying 205 patients with 350 unruptured sIAs with angiographic follow-up imaging. METHODS: In this population-based cohort study, we included unruptured sIA patients from the Kuopio University Hospital Intracranial Aneurysm Patient and Family database with at least 6 mo of angiographic follow-up after the diagnosis of sIAs. Angiograms were re-evaluated to detect aneurysms with growth of at least 1.0 mm. Cox regression analysis with patient- and aneurysm-related risk factors was used to calculate hazard ratios with 95% confidence intervals for growth. In addition, we tested the diagnostic value of previously introduced PHASES score for the prediction of sIA growth in Eastern Finnish population. RESULTS: Of the 350 unruptured aneurysms, 36 (10.3%) showed growth during median follow-up of 1.7 yr and total follow-up of 790 yr. In the multivariate Cox regression analysis, sIA size and location in the middle cerebral artery were significant risk factors for sIA growth. In receiver operator characteristic curves, both PHASES score and sIA size had relatively low areas under the curve. CONCLUSION: Our study indicates that aneurysm size is the strongest risk factor for aneurysm growth in Eastern Finnish population. Further studies are required to identify new risk factors for aneurysm growth.

Effects of knee flexion and extension on the tibial tuberosity-trochlear groove (TT-TG) distance in adolescents.

BACKGROUND: Measurement of the tibial tubercle-trochlear groove (TT-TG) distance is used to assess patellofemoral instability and rotation. Since patellofemoral instability and acute patellar dislocation are common among adolescents, it is important to clarify the relationship between TT-TG distance and various flexion and extension angles in asymptomatic children. The purpose of the present study was to determine how knee flexion and extension influence TT-TG-distance values measured using 3D imaging in an anatomic axial plane among asymptomatic adolescents. METHODS: We performed magnetic resonance imaging (MRI) of 26 knees in 13 adolescents (8 boys and 5 girls) of 11-17 years of age, with no known patellofemoral disorders. Imaging was performed with 3.0 T MRI with the knee at four separate angles of flexion between 0° and 30°. Measurements were made by two independent blinded raters. RESULTS: The mean TT-TG distance in millimetres was 11.1-0.29 × the angle in degrees. TT-TG distance decreased with greater flexion, showing a mean decrease of 0.29 mm (SD, 0.04) per degree of increased flexion (p < 0.001). We found significant inter-observer (Pearson's r = 0.636, p = 0.03) and intra-observer (Pearson's r = 0.792, p ≤ 0.001) correlations. TT-TG values were not significantly correlated with age, length, weight, or body mass index. The rate of TT-TG change (change between consecutive TT-TG values/change between consecutive angles) was significantly negatively correlated with length (p = 0.014), weight (p = 0.004), and body mass index (p = 0.025). CONCLUSIONS: Our data revealed that TT-TG distance assessed in the anatomic axial plane decreased with greater flexion in adolescent. Moreover, this effect of knee angle was stronger in smaller subjects. These findings support the need for a standardized protocol for TT-TG distance measurement in adolescents.

Mechanical Thrombectomy of Large Artery Occlusion Is Beneficial in Octogenarians.

AIM: Recent trials have established the benefit of endovascular treatment (EVT) for patients with acute ischemic stroke (AIS) due to large artery occlusion (LAO). However, older patients were often excluded from trials. EVT outcomes were retrospectively compared between octogenarians and younger patients treated for LAO in a tertiary hospital. PATIENTS AND METHODS: A total of 199 consecutive patients with anterior circulation AIS that underwent EVT between 2009 and 2015 in the Kuopio University Hospital were included. Patients were dichotomized into younger (<80 years, N=162) and older (≥80 years, N=37) groups. Baseline, imaging, and procedural characteristics, the 3-month modified Rankin Scale (mRS), and 1-year mortality were assessed. To conduct a number-needed-to-treat (NNT) analysis, data on age-dichotomized control groups from a meta-analysis were acquired. RESULTS: Compared to younger patients, older patients exhibited atrial fibrillation (57% vs. 21%, p<0.01) and coronary artery disease (49% vs. 20%, p<0.01) more frequently and Internal Carotid Artery (ICA) occlusion less frequently (22% vs. 55%, p<0.01). Similar proportions of patients received preprocedural intravenous recombinant tissue-type plasminogen activator (r-tPA; 57% vs. 67%), general anesthesia (35% vs. 41%), and reperfusion (Thrombolysis in Cerebral Infarction scale 2b/3; 76% vs. 75%). Older patients had more complications during hospitalization (41% vs. 24%, p=0.034), higher 3-month mRS values (4.0±2.3 vs. 2.8±1.9, p<0.01), fewer favorable mRS values (mRS≤2: 27% vs. 52%, p<0.01), and higher 3-month (46% vs. 10% p<0.01) and 1-year mortality (49% vs. 11%, p<0.01). The NNT to achieve an additional patient with an independent outcome (mRS≤2) was 12 among older and six among younger patients. CONCLUSION: Despite a poor recovery rate, octogenarians benefitted from EVT for AIS, with a NNT comparable to that of younger patients treated with intravenous r-tPA.

Drug-Eluting Stent Shows Similar Patency Results as Prosthetic Bypass in Patients with Femoropopliteal Occlusion in a Randomized Trial.

BACKGROUND: Claudication and critical limb threatening ischemia are significant causes of mortality in the elderly. The gold standard of superficial femoral artery (SFA) revascularization is thus far considered to be the femoropopliteal bypass. The aim of this study was to compare mid-term patency between drug-eluting stents (DESs) and prosthetic bypass grafts (BSX). Studies have reported comparable results for both the methods. METHODS: Forty-six patients with claudication or rest pain due to a 5-25 cm SFA occlusion were randomized between DES and BSX groups. The follow-up period was 24 months, and the primary outcome measure was overall patency. Secondary outcome measures were primary and primary assisted patency, change in ankle-brachial index (ABI), and amputation-free survival. RESULTS: Forty-one patients were eventually analyzed. Six-month secondary patency was 91% (DES) versus 83% (BSX) (P = 0.450). The corresponding numbers at 12 months in the DES and BSX groups were 74% and 80% (P = 0.750), respectively. At 24 months, the respective numbers were 56% and 71% (P = 0.830). There were no statistically significant differences in primary or assisted primary patency at 1, 6, or 12 months. CONCLUSION: There were no demonstrable differences in patency rates or clinical outcomes such as ABI or major amputations between DES and BSX. Although underpowered, the results suggest noninferiority of the DES compared with prosthetic bypass surgery. TRIAL REGISTRATION: The trial was preregistered at ClinicalTrials.org (NCT01450722).

Treatment options for acute mesenteric ischemia have improved.

Acute mesenteric ischemia resulting from mesenteric arterial thrombosis is a life-threatening cardiovascular complication with symptoms ranging from sudden-onset abdominal pain to vague symptoms of several days' duration. Although contrast-enhanced computed tomography is an excellent diagnostic tool, detection of the disease before the development of permanent intestinal injury is still difficult. Endovascular treatment is usually successful in restoring intestinal blood flow acutely. Chronic mesenteric ischemia requires urgent detection and therapy in order to prevent irreversible intestinal ischemia.

Irregular Shape Identifies Ruptured Intracranial Aneurysm in Subarachnoid Hemorrhage Patients With Multiple Aneurysms.

BACKGROUND AND PURPOSE: We investigated which aneurysm-related risk factors for rupture best discriminate ruptured versus unruptured saccular intracranial aneurysms (sIAs) in subarachnoid hemorrhage patients with multiple sIAs. METHODS: We included 264 subarachnoid hemorrhage patients with a ruptured sIA and at least one additional unruptured sIA, from the Kuopio Intracranial Aneurysm database from 2003 to 2015. These patients had 268 ruptured and 445 unruptured sIAs. Angiograms of the 713 sIAs were reevaluated for multiple variables describing aneurysm shape. Multivariate generalized linear mixed models were used to calculate odds ratios with corresponding 95% confidence intervals for the independent risk factors for aneurysm rupture. RESULTS: In the multivariate analysis, only sIA size (P<0.004) and irregular shape (P<0.000) independently associated with sIA rupture. As an independent risk factor, irregular shape showed the strongest association with rupture (odds ratio 90.3; 95% confidence interval, 47.0-173.5). The sIA location, flow angles, bottleneck factor, or aspect ratio were not significantly associated with rupture. CONCLUSIONS: Irregular shape may identify the ruptured sIA better than size in patients presenting with aSAH and multiple sIAs.

Pharmacomechanical Thrombectomy in Paget-Schroetter Syndrome.

PURPOSE: The purpose of the study was to evaluate feasibility of pharmacomechanical thrombectomy (PMT) in the treatment of Paget-Schroetter syndrome (PSS) followed by thoracoscopic or open surgical decompression of the subclavian vein. METHODS: Twenty-two out of 27 consecutive patients with PSS received PMT using the Trellis-8 peripheral infusion system (Covidien) between 2010 and 2014. Subsequent surgery was performed in 18 of those patients, 9 patients were treated with thoracoscopic, 7 patients with subclavicular, and 2 patients with transaxillary first rib resection, 4 patients were treated with PMT and anticoagulation alone. Technical success, complications, and patency were registered. RESULTS: PMT was successful in 21 (95 %) patients; 1 patient with unsatisfactory lysis received further catheter-directed thrombolysis, which, however, did not improve the result. The mean endovascular procedure time was 105 ± 33 min (range 70-200 min), and the required median amount of thrombolytic agent was 500,000 international unit (IU; range 250,000-1,000,000 IU). Adjunctive balloon venoplasty and aspiration were used in 18 (82 %) and 7 (32 %) cases, respectively. One patient had an intimal tear of the subclavian vein that was discovered and repaired during surgery. There were no other complications related to the endovascular procedure. At follow-up, 18 of 21 patients (86 %) with follow-up imaging available had patent subclavian vein, and all except 1 of the 22 patients were asymptomatic. The mean follow-up time was 25 ± 17 months. CONCLUSIONS: In experienced hands, PMT is effective for early thrombus removal in PSS. Surgical decompression must be considered after PMT.

Interpretation of Abdominal CT Findings in Patients Who Develop Acute on Chronic Mesenteric Ischemia.

BACKGROUND: We studied whether ischemia-specific computed tomography (CT) findings are consistently detectable in patients who develop acute on chronic mesenteric ischemia (AOCMI), whereas absent in chronic mesenteric ischemia (CMI). METHODS: Consecutive patients with symptomatic angiography-verified atherosclerotic obstruction of the superior mesenteric artery (SMA) were categorized as AOCMI (n = 27) or CMI (n = 20). Three experienced radiologists blindly evaluated the contrast-enhanced CTs for vascular and intestinal findings. Kappa statistics was used to test interobserver agreement. RESULTS: Two observers had substantial agreement (k = 0.66) that two thirds of AOCMI patients showed ischemia-specific CT findings (decreased bowel wall enhancement, pneumatosis, or thrombotic SMA clot); the third observer agreed only fairly regarding pneumatosis and thrombosis (k = 0.3-0.4). All observers had substantial agreement (k = 0.65-0.71) that most patients with AOCMI had unspecific intestinal findings such as mesenteric fat stranding in up to 96%, bowel lumen dilatation in 93%, and bowel wall thickening in 70%, while only few patients with CMI had such findings (due to chronic ischemic colitis) (P < 0.001). CONCLUSION: One third of AOCMI patients presented without any ischemia-specific CT signs. However, any intestinal abnormality in CT together with SMA obstruction should raise suspicion of intestinal ischemia. Furthermore, clinicians need to be aware of the interobserver variability in the CT interpretation.

Imaging of an acute stroke patient when planning therapy for arterial thrombosis.

Intra-arterial thrombectomy is a highly effective mode of treatment for properly selected patients with acute cerebral ischemia. Imaging studies are essential for making a decision on the treatment of acute cerebral infarction. In imaging, a combination of unenhanced CT scan of the head and CT angiography of the carotid and cerebral arteries during one imaging procedure is recommended for all patients coming into the hospital within the time window for thrombectomy, for patients with unclear time of onset of the symptoms and for whom cerebral hemorrhage is excluded as the cause in unenhanced CT scan. This may further be complemented with CT perfusion imaging. In certain acute situations magnetic resonance imaging is also useful.

Detecting acute mesenteric ischemia in CT of the acute abdomen is dependent on clinical suspicion: Review of 95 consecutive patients.

OBJECTIVES: (1) To evaluate the ability of emergency room radiologists to detect acute mesenteric ischemia (AMI) from computed tomography (CT) images in patients with acute abdominal pain. (2) To identify factors affecting radiologists' performance in the CT interpretation and patient outcome. MATERIALS AND METHODS: A retrospective study of 95 consecutive patients treated for 97 AMI events between 2009 and 2013 was carried out. The etiology of AMI was embolism in 24 (25%), atherosclerotic vascular disease (ASVD) in 39 (40%), non-obstructive mesenteric ischemia (NOMI) in 25 (26%), and mesenteric venous thrombosis (MVT) in nine (9%) cases. The protocols, referrals and initial radiology reports of the abdominal CTs were analyzed. The CT studies were further scrutinized for vascular and intestinal findings. RESULTS: The referring clinician had suspected AMI in 30 (31%) cases prior to imaging. The crucial findings of AMI had been stated in 97% of the radiology reports if the clinician had mentioned AMI suspicion in the referral; if not, the corresponding rate was 81% (p=0.04). Patients without suspicion of AMI prior to CT were more prone to undergo bowel resection. CT protocol was optimal for AMI (with contrast enhancement in arterial and venous phases) in only 34 (35%) cases. Intestinal findings were more difficult to detect than vascular findings. Vascular findings were retrospectively detectable in 92% of cases with embolism and 100% in ASVD and MVT. Some evidence of intestinal abnormality was retrospectively found in the CT findings in 92%, 100%, 100% and 67% of cases with embolism, ASVD, NOMI and MVT, respectively. CONCLUSIONS: AMI is underdiagnosed in the CT of the acute abdomen if there is no clinical suspicion.

Acute Mesenteric Ischemia Is a More Common Cause than Expected of Acute Abdomen in the Elderly.

BACKGROUND: The incidence of acute mesenteric ischemia (AMI) increases exponentially with age. The significance of AMI as a differential diagnosis in elderly patients with acute abdomen may be underestimated. METHODS: Consecutive patients hospitalized for AMI between 2009 and 2013 were retrospectively identified in a well-defined population. Acute appendicitis, ruptured abdominal aortic aneurysm, acute pancreatitis, and acute cholecystitis were used as reference diagnoses, and the age-specific incidence rates were calculated. In addition, long-term mortality risk was assessed for AMI survivors. RESULTS: The in-hospital incidence rates of AMI, acute obstructive mesenteric ischemia, and non-obstructive mesenteric ischemia were 7.3, 4.5, and 2.0/100,000/year, respectively. AMI was more common than ruptured abdominal aortic aneurysm, and the age-specific incidence of AMI was higher than the incidence of acute appendicitis in patients over age 75 years with acute abdomen. During the follow-up, the age-adjusted risk of death was 1.8 times higher in AMI survivors than in survivors of acute cholecystitis. CONCLUSION: AMI may be a more common cause of acute abdomen in elderly patients than is generally thought, emphasizing the importance of performing urgent computed tomography with contrast enhancement preferably in arterial and venous phases in these patients.

Endovascular Therapy as a Primary Revascularization Modality in Acute Mesenteric Ischemia.

PURPOSE: To evaluate endovascular therapy (EVT) as the primary revascularization method for acute mesenteric ischemia (AMI). METHODS: A retrospective review was performed on all consecutive patients treated for AMI during a 5-year period (January 2009 to December 2013). EVT was attempted in all patients referred for emergent revascularization. Surgical revascularization was performed selectively after failure of EVT. Patient characteristics, clinical presentation, and outcomes were studied. Failures and complications of EVT were recorded. RESULTS: Fifty patients, aged 79 ± 9 years (mean ± SD), out of 66 consecutive patients with AMI secondary to embolic or thrombotic obstruction of the superior mesenteric artery were referred for revascularization. The etiology of AMI was embolism in 18 (36 %) and thrombosis in 32 (64 %) patients. EVT was technically successful in 44 (88 %) patients. Mortality after successful or failed EVT was 32 %. The rates of emergency laparotomy, bowel resection, and EVT-related complication were 40, 34, and 10 %, respectively. Three out of six patients with failure of EVT were treated with surgical bypass. EVT failure did not significantly affect survival. CONCLUSIONS: EVT is feasible in most cases of AMI, with favorable patient outcome and acceptable complication rate.