Circulating Microparticles in Patients with Symptomatic Carotid Disease Are Related to Embolic Plaque Activity and Recent Cerebral Ischaemia.

BACKGROUND AND PURPOSE: In order to assess the association of microparticles derived from activated platelets (PMP) or endothelial cells (EMP) with risk markers for recurrent embolic events in patients with symptomatic carotid artery disease, we studied the associations between PMP/EMP and three risk markers: plaque haemorrhage (PH), micro-embolic signals and cerebral diffusion abnormalities. METHODS: Patients with recently symptomatic high-grade carotid artery stenosis (60-99%, 42 patients, 31 men; mean age 75 ± 8 years) and 30 healthy volunteers (HV, 11 men; mean age 56 ± 12 years) were prospectively recruited. Patients were characterised by carotid magnetic resonance imaging (presence of PH [MRI PH]), brain diffusion MRI (cerebral ischaemia [DWI+]) and transcranial Doppler ultrasound (micro-embolic signals [MES+]). PMP and EMP were classified by flow cytometry and expressed as log-transformed counts per microlitre. RESULTS: MES+ patients (n = 18) had elevated PMP (MES+ 9.61 ± 0.57) compared to HV (8.80 ± 0.73; p < 0.0001) and to MES- patients (8.55 ± 0.85; p < 0.0001). Stroke patients had elevated PMP (9.49 ± 0.64) and EMP (6.13 ± 1.0) compared to non-stroke patients (PMP 8.81 ± 0.73, p = 0.026, EMP 5.52 ± 0.65, p = 0.011) and HV (PMP 8.80 ± 0.73, p = 0.007, and EMP 5.44 ± 0.47, p = 0.006). DWI+ patients (n = 16) showed elevated PMP (DWI+ 9.53 ± 0.64; vs. HV, p = 0.002) and EMP (DWI+ 5.91 ± 0.99 vs. HV 5.44 ± 0.47; p = 0.037). Only PMP but not EMP were higher in DWI+ versus DWI- patients (8.67 ± 0.90; p = 0.002). No association was found between PMP and EMP with MRI PH. CONCLUSIONS: PMP and EMP were associated with stroke and recent cerebrovascular events (DWI+) but only PMP were also associated with ongoing (MES+) thrombo-embolic activity suggesting a differential biomarker potential for EMP to index cerebral ischaemia while PMP may predict on-going thrombo-embolic activity.

Magnetic Resonance Imaging Plaque Hemorrhage for Risk Stratification in Carotid Artery Disease With Moderate Risk Under Current Medical Therapy.

BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI)-defined carotid plaque hemorrhage (MRIPH) can predict recurrent cerebrovascular ischemic events in severe symptomatic carotid stenosis. It is less clear whether MRIPH can improve risk stratification despite optimized medical secondary prevention in those with moderate risk. METHODS: One-hundred fifty-one symptomatic patients with 30% to 99% carotid artery stenosis (median age: 77, 60.5% men) clinically deemed to not benefit from endarterectomy were prospectively recruited to undergo MRI and clinical follow-up (mean, 22 months). The clinical carotid artery risk score could be evaluated in 88 patients. MRIPH+ve was defined as plaque intensity >150% that of adjacent muscle. Survival analyses were performed with recurrent infarction (stroke or diffusion-positive cerebral ischemia) as the main end point. RESULTS: Fifty-five participants showed MRIPH+ve; 47 had low, 36 intermediate, and 5 high carotid artery risk scores. Cox regression showed MRIPH as a strong predictor of future infarction (hazard ratio, 5.2; 95% confidence interval, 1.64-16.34; P=0.005, corrected for degree of stenosis), also in the subgroup with 50% to 69% stenosis (hazard ratio, 4.1; 95% confidence interval, 1-16.8; P=0.049). The absolute risk of future infarction was 31.7% at 3 years in MRIPH+ve versus 1.8% in patients without (P<0.002). MRIPH increased cumulative risk difference of future infarction by 47.1% at 3 years in those with intermediate carotid artery risk score (P=0.004). CONCLUSIONS: The study confirms MRIPH to be a powerful risk marker in symptomatic carotid stenosis with added value over current risk scores. For patients undergoing current secondary prevention medication with clinically uncertain benefit from recanalization, that is, those with moderate degree stenosis and intermediate carotid artery risk scores, MRIPH offers additional risk stratification.

Long-term outcome of endovascular repair of popliteal artery aneurysm presents a credible alternative to open surgery.

PURPOSE: Endovascular repair of popliteal artery aneurysms (PAA) has become increasingly popular; however, long-term patency and limb salvage rates are not fully established. METHODS: A retrospective review of all endovascular PAA repairs at our institution (from 2005 to 2012) identified 34 PAAs in 26 patients, of which 32 % presented with acute symptoms. PAA were repaired with either Hemobahn(®) or Viabahn(®) endografts, using an entirely percutaneous approach. All patients were given Clopidogrel and/or aspirin postoperatively. Mean follow-up duration was 40 (range 4-86) months. Kaplan-Meier analysis was used to determine primary patency, secondary patency, and limb salvage rates. Complications and reintervention rates also were examined. RESULTS: At 1, 3, and 5 years follow-up, the primary graft patency was 88, 82, and 82 %, respectively, and secondary patency was 90, 86, and 86 %. Amputation-free survival at 1, 3, and 5 years was 97, 94, and 94 %, respectively. Technical success was achieved in 100 %. There were five graft occlusions: one was asymptomatic, one was treated with thrombolysis successfully, and one was thrombolysed but reoccluded resulting in nondisabling claudication. Two were not suitable for thrombolysis and required amputation. The overall reintervention rate was 12 %. CONCLUSIONS: The primary and secondary patency rates of endovascular repair of PAA are equivalent to the reported outcome of open repair. Reintervention and limb salvage rate appears better than open repair. With improved long-term outcomes, endovascular repair can be considered a credible treatment strategy for routine uncomplicated PAA.

Magnetic resonance detected carotid plaque hemorrhage is associated with inflammatory features in symptomatic carotid plaques.

BACKGROUND: Both magnetic resonance detected carotid plaque hemorrhage (MRI PH(+)) and features of inflammation are associated with increased risk of cerebrovascular events in patients with carotid stenosis. To further assess the potential of MRI PH as a biomarker for complicated carotid plaque, its relationship with inflammation needs to be assessed. In this study we assess whether MRI PH(+) carotid plaques are associated with inflammatory infiltration. METHODS: Thirty-five consecutive patients with symptomatic, high-grade carotid stenosis scheduled for carotid endarterectomy had preoperative MRI. The carotid plaques removed at operation were assessed for inflammatory features and compared with MRI findings. RESULTS: Twenty-one (60%) carotid arteries were MRI PH(+) and 14 (40%) were MRI PH(-). The MRI PH(+) plaques were associated with histologic evidence of plaque hemorrhage, high lipid proportion, and low fibrous content. They also had higher levels of macrophage and lymphoid cells compared with MRI PH(-) plaques (P < 0.05, by χ² test) and were more likely to be AHA VI (P < 0.005, χ² test). MRI PH(+) plaques were also more likely to be graded as unstable based on morphology and cellular composition. CONCLUSIONS: These findings demonstrate an association between MRI PH and signs of active plaque disease. The relationship between inflammatory activity and plaque instability may thus explain the increased risk associated with MRI PH(+) plaques and increased risk of symptoms.

Carotid plaque hemorrhage on magnetic resonance imaging strongly predicts recurrent ischemia and stroke.

OBJECTIVE: There is a recognized need to improve selection of patients with carotid artery stenosis for carotid endarterectomy (CEA). We assessed the value of magnetic resonance imaging (MRI)-defined carotid plaque hemorrhage (MRIPH) to predict recurrent ipsilateral cerebral ischemic events, and stroke in symptomatic carotid stenosis. METHODS: One hundred seventy-nine symptomatic patients with ≥ 50% stenosis were prospectively recruited, underwent carotid MRI, and were clinically followed up until CEA, death, or ischemic event. MRIPH was diagnosed if the plaque signal intensity was >150% that of the adjacent muscle. Event-free survival analysis was done using Kaplan-Meier plots and Cox regression models controlling for known vascular risk factors. We also undertook a meta-analysis of reported data on MRIPH and recurrent events. RESULTS: One hundred fourteen patients (63.7%) showed MRIPH, suffering 92% (57 of 62) of all recurrent ipsilateral events and all but 1 (25 of 26) future strokes. Patients without MRIPH had an estimated annual absolute stroke risk of only 0.6%. Cox multivariate regression analysis proved MRIPH as a strong predictor of recurrent ischemic events (hazard ratio [HR] = 12.0, 95% confidence interval [CI] = 4.8-30.1, p < 0.001) and stroke alone (HR = 35.0, 95% CI = 4.7-261.6, p = 0.001). Meta-analysis of published data confirmed this association between MRIPH and recurrent cerebral ischemic events in symptomatic carotid artery stenosis (odds ratio = 12.2, 95% CI = 5.5-27.1, p < 0.00001). INTERPRETATION: MRIPH independently and strongly predicts recurrent ipsilateral ischemic events, and stroke alone, in symptomatic ≥ 50% carotid artery stenosis. The very low stroke risk in patients without MRIPH puts into question current risk-benefit assessment for CEA in this subgroup.

Lower prevalence of carotid plaque hemorrhage in women, and its mediator effect on sex differences in recurrent cerebrovascular events.

BACKGROUND AND PURPOSE: Women are at lower risk of stroke, and appear to benefit less from carotid endarterectomy (CEA) than men. We hypothesised that this is due to more benign carotid disease in women mediating a lower risk of recurrent cerebrovascular events. To test this, we investigated sex differences in the prevalence of MRI detectable plaque hemorrhage (MRI PH) as an index of plaque instability, and secondly whether MRI PH mediates sex differences in the rate of cerebrovascular recurrence. METHODS: Prevalence of PH between sexes was analysed in a single centre pooled cohort of 176 patients with recently symptomatic, significant carotid stenosis (106 severe [≥70%], 70 moderate [50-69%]) who underwent prospective carotid MRI scanning for identification of MRI PH. Further, a meta-analysis of published evidence was undertaken. Recurrent events were noted during clinical follow up for survival analysis. RESULTS: Women with symptomatic carotid stenosis (50%≥) were less likely to have plaque hemorrhage (PH) than men (46% vs. 70%) with an adjusted OR of 0.23 [95% CI 0.10-0.50, P<0.0001] controlling for other known vascular risk factors. This negative association was only significant for the severe stenosis subgroup (adjusted OR 0.18, 95% CI 0.067-0.50) not the moderate degree stenosis. Female sex in this subgroup also predicted a longer time to recurrent cerebral ischemic events (HR 0.38 95% CI 0.15-0.98, P = 0.045). Further addition of MRI PH or smoking abolished the sex effects with only MRI PH exerting a direct effect. Meta-analysis confirmed a protective effect of female sex on development of PH: unadjusted OR for presence of PH = 0.54 (95% CI 0.45-0.67, p<0.00001). CONCLUSIONS: MRI PH is significantly less prevalent in women. Women with MRI PH and severe stenosis have a similar risk as men for recurrent cerebrovascular events. MRI PH thus allows overcoming the sex bias in selection for CEA.

Early results with the use of heparin-bonded stent graft to rescue failed angioplasty of chronic femoropopliteal occlusive lesions: TASC D lesions have a poor outcome.

PURPOSE: To evaluate early patency rate of the heparin-bonded stent grafts in atherosclerotic long femoropopliteal occlusive disease, and to identify factors that affect outcome. METHODS: Heparin-bonded Viabahn stent grafts were placed in 33 limbs in 33 patients during 2009-2010. The stents were deployed to rescue failed conventional balloon angioplasty. Mean age was 69 (range 44-88) years, and 67 % (22 of 33) were men. Most procedures (21 of 33, 64 %) were performed for critical limb ischemia (33 % for rest pain, 30 % tissue loss). Kaplan-Meier plots and Cox regression analysis were used to identify significant risk factors. RESULTS: The average length of lesions treated was 25 ± 10 cm, and they were predominantly TASC (Transatlantic Intersociety Consensus) D (n = 13) and C (n = 17) lesions. The median primary patency was 5.0 months (95 % confidence interval 1.22-8.77). The mean secondary patency was 8.6 months (95 % confidence interval 6.82-10.42). Subsequently, 4 patients underwent bypass surgery and 5 patients underwent major amputation. One patient died. There were 5 in-stent or edge-stent stenoses. Cox multivariate regression analysis identified TASC D lesions to be a significant risk factor for early occlusion (p = 0.035). CONCLUSION: TASC D lesions of femoropopliteal occlusions have poor patency rates with the use of heparin-bonded stent grafts after failed conventional angioplasty. Alternative options should be considered for these patients.

Use of the Hardman index in predicting mortality in endovascular repair of ruptured abdominal aortic aneurysms.

PURPOSE: The Hardman index is a predictor of 30-day mortality after open ruptured abdominal aneurysm repair through the use of preoperative patient factors. The aim of this study was to assess the Hardman index in patients undergoing endovascular repair of ruptured aortic aneurysms. MATERIALS AND METHODS: A retrospective analysis of 95 patients undergoing emergency endovascular repairs of computed tomography-confirmed ruptured aneurysms from 1994 to 2008 in a university hospital was performed. All relevant patient variables, calculations of the Hardman index, and the incidence of 30-day mortality were collected in these patients. Correlation of the relationship between each variable and the overall score with the incidence of 30-day mortality was undertaken. RESULTS: The 24-hour mortality was 16% and 30-day mortality 36%. Increasing scores on the Hardman index showed an increasing mortality rate. Thirty-day mortality in patients with a score of 0 to 2 was 30.5%, and in those with a score of ≥3 was 69.2% (P = .01, risk ratio = 2.26, 95% confidence interval = 0.98 to 5.17). This is lower than predicted in both patient groups based on Hardman index score. Loss of consciousness was the only statistically significant independent predictor of 30-day mortality with a risk ratio of 3.16 (95% confidence interval = 2.00-4.97, P < .001). CONCLUSION: These data suggest that the Hardman index can predict an increased risk of 30-day mortality from endovascular repairs of ruptured aortic aneurysms. However, mortality from endovascular repair is much lower than would be predicted in open repair and it therefore cannot be used clinically as a tool for exclusion from intervention.

Plaque hemorrhage is a marker of thromboembolic activity in patients with symptomatic carotid disease.

PURPOSE: To assess whether carotid plaque hemorrhage depicted with magnetic resonance (MR) imaging was associated with thromboembolic activity as assessed with transcranial Doppler imaging. MATERIALS AND METHODS: The local research ethics committee approved the study, and all patients gave informed written consent. Between April 2005 and December 2006, patients with high-grade symptomatic carotid stenosis were prospectively recruited. All underwent MR imaging of the carotid arteries for plaque hemorrhage and diffusion-weighted imaging of the brain. Transcranial Doppler imaging of the symptomatic carotid artery was performed over 1 hour to assess the presence of microembolic signal. To determine the relationship between the presence of plaque hemorrhage and diffusion-weighted imaging-positive signal and presence of microembolic signal, a logistic regression analysis was performed. RESULTS: Fifty-one patients (23 women and 28 men; mean age ± standard deviation, 72 years ± 11) underwent complete MR imaging; 46 (86%) of these patients underwent complete transcranial Doppler imaging. In 32 (63%) patients, there was plaque hemorrhage in the index carotid artery. The presence of plaque hemorrhage increased the risk for ipsilateral abnormalities at diffusion-weighted imaging (odds ratio, 6.2 [95% confidence interval: 1.7, 21.8]; P < .05). Multiple diffusion-weighted imaging-depicted abnormalities of multiple ages were present exclusively in patients with plaque hemorrhage shown at MR imaging (12 of 32 [38%] patients with plaque hemorrhage versus none of 19 patients without plaque hemorrhage; P < .05). The presence of plaque hemorrhage also increased the presence of microembolic signal (odds ratio, 6.0 [95% confidence interval: 1.8, 19.9]; P = .003). CONCLUSION: In patients with carotid plaque hemorrhage demonstrated at MR imaging, there was increased spontaneous microembolic activity at transcranial Doppler imaging and cerebral ischemic lesion patterns suggestive of recurrent embolic events; these findings suggest that plaque hemorrhage shown at MR imaging might be a marker of thromboembolic activity and further validate the usefulness of carotid imaging in identifying patients with active carotid arterial disease.

Leukoaraiosis predicts the need for intraoperative shunt placement during carotid endarterectomy.

OBJECTIVES: White matter hyperintense lesions (WMHLs) are related to age, hypertension, and ischemia. They increase the risk of stroke in natural history and perioperatively during carotid endarterectomy. This may reflect an association with impaired cerebral hemodynamics. Hence, the authors studied whether ipsilateral WMHLs predict shunt requirement on clamping as an indicator of hemodynamic compromise. DESIGN AND METHODS: A retrospective analysis was done in patients with symptomatic and severe carotid stenosis (>60%). Ipsilateral WMHL volumes were calculated from magnetic resonance imaging scans and association studied with the requirement of an intraoperative shunt. RESULTS: Seventy patients were included. Twelve (17%) patients required shunting and 2 developed perioperative strokes. Patients requiring shunting had a larger WMHL volume (adjusted means = 16.2 +/- 2.9 mL compared with 8.7 +/- 1.2 mL for the nonshunt group; P = .020). CONCLUSIONS: Ipsilateral WMHL volume is a significant predictive factor for shunt requirement during carotid endarterectomy. This may reflect cerebral hemodynamic compromise.

Brain white matter hyperintensities are associated with carotid intraplaque hemorrhage.

PURPOSE: To retrospectively assess the relationship between carotid intraplaque hemorrhage (IPH), which indicates plaque instability, and brain white matter hyperintense lesions (WMHLs) by using a within-patient design. MATERIALS AND METHODS: All patients gave written informed consent for the initial magnetic resonance (MR) studies, and the institutional review board and local research ethics committee waived initial informed consent for the pooled analysis. A total of 190 patients with symptomatic carotid artery disease underwent fluid-attenuated inversion-recovery imaging of the brain and fat-suppressed black-blood T1-weighted MR imaging of the carotid arteries. The volumes of periventricular lesions, subcortical lesions, and total WMHLs were calculated and compared between hemispheres in relation to symptoms and IPH, and their interaction was calculated and compared by using repeated measures three-factorial multivariate analysis. RESULTS: After exclusion of 12 patients, 178 patients (116 men, 62 women; mean age, 70.2 years +/- 8.6 [standard deviation]) remained. There was no significant difference in WMHL volume between the symptomatic and asymptomatic hemispheres, and WMHL volume was not related to the degree of carotid stenosis. The presence of carotid IPH significantly interacted with the interhemispheric WMHL difference (Wilks lambda test, F = 9.95; df = 3; P < .001). Univariate analysis showed larger total and periventricular WMHL volumes (P < .05) in patients with ipsilateral IPH. CONCLUSION: Carotid artery disease and leukoaraiosis were associated with features that indicated plaque instability, namely IPH, whereas the degree of stenosis had no effect.

Endovascular stenting of a chronic ruptured type B thoracic aortic dissection, a second chance: a case report.

INTRODUCTION: We aim to highlight the need for awareness of late complications of endovascular thoracic aortic stenting and the need for close follow-up of patients treated by this method. CASE PRESENTATION: We report the first case in the English literature of an endovascular repair of a previously stented, ruptured chronic Stanford type B thoracic aortic dissection re-presenting with a type III endoleak of the original repair. CONCLUSION: Endovascular thoracic stenting is now a widely accepted technique for the treatment of thoracic aortic dissection and its complications. Long term follow up is necessary to ensure that late complications are identified and treated appropriately. In this case of type III endoleak, although technically challenging, endovascular repair was feasible and effective.

Detection of intraplaque hemorrhage by magnetic resonance imaging in symptomatic patients with mild to moderate carotid stenosis predicts recurrent neurological events.

BACKGROUND: Carotid endarterectomy is beneficial in severe (>70%) symptomatic carotid stenosis. The risk of stroke in moderate carotid stenosis (50%-69%) is modest, and so the role of carotid endarterectomy in this group is unclear. Intraplaque hemorrhage is associated with advanced atherosclerosis and can be detected in the carotid arteries by magnetic resonance imaging. This study evaluates whether magnetic resonance imaging detected intraplaque hemorrhage (MR IPH) can identify patients with symptomatic mild to moderate carotid stenosis who are at higher risk of ipsilateral transient ischemic attack (TIA) and stroke. METHODS: Prospective longitudinal cohort study of symptomatic patients with mild to moderate (30%-69%) carotid stenosis followed up for 2 years after imaging for IPH using magnetic resonance imaging. RESULTS: Sixty four participants were followed up for a median of 28 months (interquartile range 26-30) after MRI of the carotid arteries. Thirty-nine (61%) ipsilateral arteries showed intraplaque hemorrhage. During follow-up, five ipsilateral strokes and a total of 14 ipsilateral ischemic events were observed. Thirteen of these ischemic events, of which five were strokes, occurred in those with ipsilateral carotid intraplaque hemorrhage (hazard ratio = 9.8, 95% confidence interval 1.3-75.1, P = .03). CONCLUSIONS: MR IPH is a good predictor of ipsilateral stroke and TIA in patients with symptomatic mild to moderate (30%-69%) carotid stenosis. This technique could help in the selection of patients for carotid endarterectomy.

Carotid intraplaque hemorrhage detected by magnetic resonance imaging predicts embolization during carotid endarterectomy.

BACKGROUND: Microembolization detected during the dissection phase of carotid endarterectomy (CEA) is associated with plaque instability and might be associated with perioperative morbidity. Intraplaque hemorrhage is found in unstable plaques and is detectable using magnetic resonance imaging (MRI). We aimed to ascertain whether intraplaque hemorrhage as seen on carotid MRI predicts particulate embolization in the dissection phase of CEA. METHODS: Patients with high-grade symptomatic carotid stenosis undergoing CEA were prospectively enrolled. All underwent preoperative MRI assessment of the carotid arteries for intraplaque hemorrhage and transcranial Doppler scanning during the dissection phase of the CEA to assess the presence of microembolic signals. Associations between intraplaque hemorrhage and intraoperative microembolic signals were studied. RESULTS: Analysis was undertaken on 60 participants; of these, 36 (60%) showed ipsilateral carotid MRI intraplaque hemorrhage, and 24 (40%) did not. Microembolic signals were detected during the dissection phase in 23 (38.3%) participants, and 19 had MRI-detected intraplaque hemorrhage. The association between carotid intraplaque hemorrhage and the presence of dissection phase microembolic signals was significant (odds ratio [OR], 5.6; 95% confidence interval [CI], 1.6 to 19.7, P = .007), even after controlling for age, sex, individual surgeon, degree of stenosis, and delay from symptom to CEA (adjusted OR, 5.8; 95% CI, 1.1 to 30.4, P = .037). CONCLUSION: Intraplaque hemorrhage as detected by carotid MRI predicts particulate embolization during the dissection phase of CEA. This imaging technique can be used to identify patients with increased intraoperative thromboembolic risk, and this could influence preventive strategies.

Carotid intraplaque hemorrhage predicts recurrent symptoms in patients with high-grade carotid stenosis.

BACKGROUND AND PURPOSE: Carotid intraplaque hemorrhage (IPH), known to be associated with plaque instability, may convey a higher stroke risk. The aim of this study was to assess whether the identification of IPH by MRI predicts recurrent clinical cerebrovascular events. METHODS: Sixty-six patients with high-grade symptomatic carotid stenosis underwent MRI of the carotid arteries and were followed until carotid endarterectomy or 30 days. RESULTS: Of the 66 patients with a median follow up of 33.5 days, 44 (66.7%) were found on MRI to have ipsilateral carotid IPH. Fifteen recurrent events were associated with ipsilateral carotid IPH. Only 2 recurrent events occurred in the absence of IPH. IPH increased the risk of recurrent ischemia (hazard ratio=4.8; 95% CI=1.1 to 20.9, P<0.05). CONCLUSIONS: IPH as detected by MRI predicts recurrent cerebrovascular events in patients with symptomatic high-grade carotid stenosis.

Long-term renal function following endovascular aneurysm repair with infrarenal and suprarenal aortic stent-grafts.

PURPOSE: To determine in a retrospective analysis the incidence of renal impairment (RI) following endovascular repair (EVR) of abdominal aortic aneurysm (AAA), to assess the morbidity and mortality in endograft patients with preoperative RI, and to examine the impact of suprarenal stent-grafts on renal function. METHODS: From March 1994 to October 2001, 315 AAA patients (289 men; mean age 72.4+/-7.0 years) undergoing EVR were entered prospectively into a vascular registry. The patients received either an in-house custom-made stent-graft or one of several commercially made devices implanted with infrarenal or suprarenal fixation. Renal function was monitored by serum creatinine measurements prior to discharge and at 3, 6, and 12 months and annually thereafter. Preoperative RI was defined as a serum creatinine >130 micro mol/L and/or long-term dialysis. Postoperative RI referred to a >20% increase in the serum creatinine over baseline. Additional deterioration of renal function in patients with preoperative RI was referred to as postoperatively worsened RI. RESULTS: Of the 315 patients treated, 220 (69.8%) were considered high risk (ruptured AAA or ASA grade III or IV). Sixty-nine (21.9%) patients had preoperative RI (6 [1.9%] on preoperative dialysis). A suprarenal stent-graft was used in 169 (53.7%) patients and infrarenal stent-graft in the remaining 146 (46.3%). The mean follow-up was 30.1+/-22.7 months. Postoperative RI occurred in 53 (16.8%) patients (24 [7.6%] transient, 29 [9.2%] persistent). Patients with preoperative RI had a significantly higher incidence of postoperatively worsened RI (37.7% versus 11.0%, p<0.0001) and a higher mortality related to RI (7.2% versus 1.6%, p=0.02). Suprarenal fixation had no influence on the incidence of RI, on perioperative mortality, or on mortality related to RI. The only significant predictive factor of postoperative RI was preoperative RI (risk ratio 5.09, 95% CI 2.38 to 10.87, p=0.0001). CONCLUSIONS: Endovascular AAA repair may lead to persistent postoperative RI in nearly 10% of cases, especially in patients with preoperative RI. Suprarenal stent-graft fixation does not seem to have any deleterious effect on renal function. Further long-term studies are required to confirm the innocuous nature of transrenal stent placement.

Anatomical suitability of ruptured abdominal aortic aneurysms for endovascular repair.

PURPOSE: To assess the anatomical suitability of ruptured abdominal aortic aneurysms (AAA) for emergency endovascular repair. METHODS: All cases (46 patients [35 men; mean age 74 years, range 54-85]) in which computed tomographic angiography (CTA) confirmed AAA rupture over a 5-year period at our university hospital were reviewed for anatomical suitability for endovascular repair. Measurements were made by a radiologist experienced in anatomical assessment of CT criteria for elective endovascular aneurysm repair (EVAR). RESULTS: The mean aneurysm neck length was 18 mm (range 0-59); 17 were conical, 13 straight, 4 barrel, and 6 reverse conical. Six cases had no proximal neck. Overall, 37 (80%) patients were unsuitable for EVAR according to our criteria. Nearly half the patients (22, 48%) had > or =2 adverse features. Unsuitable neck morphology (35, 76%) was the primary reason for exclusion, but CIA aneurysm (10, 22%) and EIA tortuosity (7, 15%) were secondary adverse features. CONCLUSIONS: With current stent-graft design, the majority of ruptured abdominal aortic aneurysms are anatomically unsuitable for endovascular repair.

Characterization of complicated carotid plaque with magnetic resonance direct thrombus imaging in patients with cerebral ischemia.

BACKGROUND: Thromboembolic disease secondary to complicated carotid atherosclerotic plaque is a major cause of cerebral ischemia. Clinical management relies on the detection of significant (>70%) carotid stenosis. A large proportion of patients suffer irreversible cerebral ischemia as a result of lesser degrees of stenosis. Diagnostic techniques that can identify nonstenotic high-risk plaque would therefore be beneficial. High-risk plaque is defined histologically if it contains hemorrhage/thrombus. Magnetic resonance direct thrombus imaging (MRDTI) is capable of detecting methemoglobin within intraplaque hemorrhage. We assessed this as a marker of complicated plaque and compared its accuracy with histological examination of surgical endarterectomy specimens. METHODS AND RESULTS: Sixty-three patients underwent successful MRDTI and endarterectomy with histological examination. Of these, 44 were histologically defined as complicated (type VI plaque). MRDTI demonstrated 3 false-positive and 7 false-negative results, giving a sensitivity and specificity of 84%, negative predictive value of 70%, and positive predictive value of 93%. The interobserver (kappa=0.75) and intraobserver (kappa=0.9) agreement for reading MRDTI scans was good. CONCLUSIONS: MRDTI of the carotid vessels in patients with cerebral ischemia is an accurate means of identifying histologically confirmed complicated plaque. The high contrast generated by short T1 species within the plaque allows for ease of interpretation, making this technique highly applicable in the research and clinical setting for the investigation of carotid atherosclerotic disease.