Robert Maggisano

Traumatic rupture of the thoracic aorta: Should one always operate immediately?

Although the traditional therapy for blunt traumatic rupture of the thoracic aorta (TRA) is immediate operative repair, there may be a selective role for delayed repair, particularly in patients with head trauma, respiratory failure, or cardiac dysfunction. The present study examines the hypothesis that TRA can be managed by selective delayed operative repair. Clinical data were collected from 59 consecutive patients with TRA at a regional trauma unit. All TRAs were at the aortic isthmus. Patients were retrospectively classified into three groups: group I (n=12) included patients who either arrived in extremis or rapidly became unstable during triage; group II (n=3) included patients who had no contraindications to early repair and underwent repair at the time of diagnosis; and group III (n=44) consisted of patients who because of concomitant injuries or sepsis required initial admission and management in the intensive care unit until their clinical status had improved sufficiently to allow for deliberate delayed operative repair of the TRA. The delay ranged from 1 day to 7 months. Eight patients have yet to undergo repair and remain well at follow-up from 1 to 4 years. Overall survival rates in groups I, II, and III were 17%, 100%, and 82%, respectively. The surgery-related mortality rate in group III was 10% (three patients). Only two (4.5%) patients in group III died as a result of a ruptured aorta within 72 hours of admission. In conclusion, contrary to surgical doctrine, TRA may not require immediate operative repair in all cases, but may instead be managed selectively depending on the patients clinical status.

Moderate Carotid Artery Stenosis: MR Imaging–depicted Intraplaque Hemorrhage Predicts Risk of Cerebrovascular Ischemic Events in Asymptomatic Men

PURPOSEnTo investigate the association between magnetic resonance (MR) imaging-depicted intraplaque hemorrhage (IPH) in the carotid artery wall and the risk of future ipsilateral cerebrovascular events in men with asymptomatic moderate carotid stenosis by using a rapid three-dimensional T1-weighted fat-suppressed spoiled gradient-echo sequence.nnnMATERIALS AND METHODSnThe institutional ethics review board approved this retrospective chart review and waived the requirement for written informed consent. All patients gave informed verbal consent at follow-up telephone interviews. Ninety-one men (mean age, 74.8 years; range, 47-88 years) who attended a vascular clinic between 2003 and 2006, who had asymptomatic carotid stenosis (50%-70% at Doppler ultrasonography), and who had undergone MR imaging for IPH detection were retrospectively identified. Seventy-five men with 98 eligible carotid arteries were included in the study. Patients were followed for a minimum of 1 year (mean follow-up, 24.92 months; range, 12-43 months). Kaplan-Meier survival and univariate Cox regression analyses were conducted to compare future ipsilateral cerebrovascular event rates between carotid arteries with and those without MR-depicted IPH.nnnRESULTSnOf the 98 carotid arteries included, 36 (36.7%) had MR-depicted IPH. Six cerebrovascular events (two strokes and four transient ischemic attacks) occurred in the carotid arteries with IPH, as compared with no clinical events in the carotid arteries without IPH. Univariate Cox regression analysis confirmed that MR-depicted IPH was associated with an increased risk of cerebrovascular events (hazard ratio, 3.59; 95% confidence interval: 2.48, 4.71; P < .001). MR-depicted IPH negatively predicted outcomes (negative predictive value = 100%).nnnCONCLUSIONnIn this cohort with asymptomatic moderate carotid stenosis, MR-depicted IPH was associated with future ipsilateral cerebrovascular events. Conversely, patients without MR-depicted IPH remained asymptomatic during follow-up. The absence of IPH at MR imaging, therefore, may be a reassuring marker of plaque stability and of a lower risk of thromboembolism.

Measuring carotid stenosis. Time for a reappraisal.

Background and Purpose Data from recent multicenter carotid endarterectomy trials have questioned the validity and reliability of Doppler ultrasound in the assessment of carotid stenosis. Methods We prospectively analyzed 45 patients undergoing carotid angiography to compare the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) methods of measuring carotid stenosis with those of direct visualization (“eyeballing”) and duplex ultrasound. Linear NASCET and ECST measurements were also converted into area using the πr2 function and termed “squared NASCET” (N2) and “squared ECST” (E2). In 15 of 45 patients undergoing carotid endarterectomy, the carotid plaque was removed intact, sectioned, and photographed for computer measurement of cross-sectional area. Comparison of this “gold standard” was then made to each method of measurement. Results Comparison between duplex and the various angiographic measurement techniques revealed significant differences between NASCET and duplex (P<.0001), ECST and duplex (P<.01), and E2 and duplex (P<.01) but not between N2 eyeballing, and carotid duplex methods. Even the NASCET and ECST methods themselves differed significantly (P<.006). When comparison was made with computerized planimetric measurements of the carotid plaque, there were significant differences for both NASCET (P<.0007) and ECST (P<.007). Correlation was demonstrated only between planimetry and N2, E2, and duplex. Conclusions NASCET and ECST angiographic methods of measurement consistently underestimate the “true” anatomic stenosis. As such, they represent only “indexes” of carotid stenosis severity. Duplex provides a more accurate measurement of carotid stenosis.

Carotid artery stenosis in peripheral vascular disease

PURPOSEnThe goal of the study was to assess the prevalence and severity of symptomatic and asymptomatic carotid artery disease in patients with peripheral vascular disease (PVD).nnnMETHODSnConsecutive patients with clinically and Doppler scanning-proven PVD (category 1 or greater) underwent prospective screening for the presence of carotid atherosclerosis with color-coded duplex ultrasonography. Preexisting risk factors were recorded with a standard questionnaire and included sex, age, diabetes mellitus, history of smoking, hypertension, prior stroke/transient ischemic attacks, and coronary artery disease.nnnRESULTSnThree hundred seventy-three consecutive patients were studied over 2 years. The mean age of the patients was 70 +/- 10 years; there were 223 (60%) men and 150 (40%) women; 71% of the patients had a history of smoking, 47% had coronary artery disease, 43% had hypertension, and 21% had diabetes mellitus. Two hundred eleven (57%) patients had 30% or greater carotid artery stenosis detected by carotid artery duplex scanning. Sixty-seven (32%) of these had symptoms of ischemic cerebral events, of whom 22 had potentially operable carotid artery stenoses (70% to 99%), whereas 72 of the 144 symptom-free patients had 60% to 99% stenosis. An additional 34 patients would be eligible candidates for the ongoing carotid endarterectomy trials (North American Symptomatic Carotid Endarterectomy Trial and European Carotid Surgery Trial). Although all the risk factors were associated significantly with PVD and carotid artery disease (p < 0.002), male sex and prior stroke/transient ischemic attack were the strongest predictors.nnnCONCLUSIONSnRoutine carotid ultrasound screening of 373 consecutive patients with category I or greater PVD revealed that 22 patients with symptoms and 72 symptom-free patients were potential surgical candidates, representing 25% of the study cohort. An additional 34 patients were potential candidates for enrollment into the North American Symptomatic Carotid Endarterectomy Trial and European Carotid Surgery Trial.

In Vivo 3D High-Spatial-Resolution MR Imaging of Intraplaque Hemorrhage

PURPOSEnTo apply magnetic resonance (MR) imaging of intraplaque hemorrhage (IPH), as compared with histologic analysis as the reference standard, to detect T1 hyperintense intraplaque signal and to test the hypothesis that T1 hyperintense material represents blood products (methemoglobin).nnnMATERIALS AND METHODSnInstitutional review board approval and patient informed consent were obtained. Eleven patients undergoing carotid endarterectomy were examined with MR imaging of IPH, and MR images were assessed for T1 hyperintense intraplaque signal. A total of 160 images per patient were available for coregistration with corresponding histologic slices. Because of endarterectomy specimen size and degradation and processing artifacts, only 97 images were coregistered to corresponding histologic slices. A grid that consisted of 16 segments was overlaid on images for correlation of MR images and histologic slices. Only one of 16 segments was chosen randomly per slide and used in the analysis. Agreement between MR images and histologic slices was measured with the Cohen kappa statistic.nnnRESULTSnStrong agreement was seen between MR images and histologic slices, with T1-weighted high signal intensity corresponding to hemorrhagic material (kappa = 0.7-0.8). There was a low 2% false-negative rate for the detection of hemorrhage on the basis of T1-weighted hyperintensity (two of 97 measured segments). The results of diagnostic tests for T1 hyperintense detection of hemorrhage were as follows: sensitivity of 100%, specificity of 80%, positive predictive value of 70%, and negative predictive value of 100% for reader 1 and sensitivity of 94%, specificity of 88%, positive predictive value of 78%, and negative predictive value of 97% for reader 2.nnnCONCLUSIONnWith its high spatial resolution, MR imaging of IPH permits detection of plaque hemorrhage location, resulting in strong agreement between imaging and histologic findings.

Carotid Stenosis Index A New Method of Measuring Internal Carotid Artery Stenosis

BACKGROUND AND PURPOSEnCurrent methods of measuring carotid stenosis such as those used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) have limitations caused by difficulties in measuring the normal width of the distal internal carotid artery (ICA) or the carotid bulb.nnnMETHODSnWe developed a new technique, the Carotid Stenosis Index (CSI), based on the known anatomic relationship between the common carotid artery (CCA) and ICA (1.2 x CCA diameter=proximal ICA diameter). The normal ICA diameter can therefore be calculated from direct measurement of the CCA. Three blinded observers evaluated the angiograms of 57 patients (114 carotid arteries), previously screened with duplex ultrasonography, using the NASCET, ECST, and CSI methods. In a subset of 30 patients undergoing carotid endarterectomy, comparison was also made to computerized carotid plaque planimetry.nnnRESULTSnThe NASCET method could only be applied correctly in 89% and the ECST method in 95% of cases because of overlying vessels or inadequate views of the distal ICA or carotid bulb. An additional 9% of NASCET cases had a negative stenosis, in which the stenosis is wider than the distal ICA. The CSI method was applicable in 99% of cases. Interobserver comparison using ANOVA revealed significant differences using NASCET (P < .0001) and ECST (P <.001) but not CSI (P = NS). NASCET had a sevenfold variation (P < .01) and ECST a twofold variation (P < .01) in results compared with CSI. The intraobserver reliability was 0.87 for NASCET, 0.86 for ECST, and 0.90 for CSI. However, the 95% confidence intervals for an individual measurement by an observer were +/- 30% for NASCET, +/- 19% for ECST, and +/- 15% for CSI. With linear methods of measurement there were significant differences between NASCET and CSI (P < .0001) and ECST (P < .0001) but not between CSI and ECST. A comparison of area derivations of these methods to carotid plaque planimetry revealed significant differences from NASCET (P <.0001) but not ECST, CSI, or duplex methods. A CSI nomogram was created, allowing measurement of both linear and area percent stenosis.nnnCONCLUSIONSnCSI is the most reliable validated method of measuring carotid stenosis, and it correlates with duplex and carotid pathology.

Blunt diaphragmatic and thoracic aortic rupture: An emerging injury complex

Although both blunt diaphragmatic rupture (BDR) and thoracic aortic rupture (TAR) have been extensively discussed, the association of both injuries has been infrequently mentioned. The purpose of this study was to examine the current prevalence and clinical characteristics of combined BDR and TAR at an adult regional trauma unit. Among 3,886 trauma victims, 69 (1.8%) had a BDR and 44 (1.1%), a TAR. Seven patients (10% of all patients with a BDR) had both injuries. All 7 were victims of motor vehicle crashes and had a mean Injury Severity Score of 35. All TARs were just distal to the origin of the left subclavian artery. Five patients underwent repair of both injuries and survived, 1 patient had only the BDR repaired and survived, and 1 died during emergency thoracotomy, for a survival rate of 86%. Five patients had laparotomy and repair of the BDR in the presence of an unrepaired TAR. The TARs were repaired by the clamp-and-sew technique, three of them with primary repair and two with interposition tube grafts. Concomitant BDR and TAR appears to be an emerging injury complex with both diagnostic and therapeutic challenges. The presence of BDR demands a rigorous search for associated TAR.

In Vivo Identification of Complicated Upper Thoracic Aorta and Arch Vessel Plaque by MR Direct Thrombus Imaging in Patients Investigated for Cerebrovascular Disease

OBJECTIVEnThe objective of this article was to assess the feasibility of MR direct thrombus imaging (MRDTI) to evaluate the prevalence and location of complicated upper thoracic aortic and arch vessel plaque in patients referred for evaluation of cerebrovascular disease.nnnSUBJECTS AND METHODSnPatients referred for investigation of cerebrovascular disease by MRI were enrolled. Reasons for referral included transient ischemic attack/amaurosis fugax, acute infarct, remote infarct, or asymptomatic carotid disease. Of the 348 patients initially scanned, 17 were excluded from the analysis. The final patient population included 331 patients (199 men, 132 women; mean age, 67.7 years). Patients were scanned using MRDTI, a 3D, T1-weighted, fat-suppressed spoiled gradient echo that exploits the T1 shortening effects of methemoglobin, directly visualizing hemorrhage/thrombus in the vessel wall, thus identifying complicated plaque. Complicated plaque was defined as a high signal within the atherosclerotic plaque at least twice the signal intensity of muscle.nnnRESULTSnForty-three of 331 patients (13%) had complicated upper thoracic aortic atherosclerotic disease, arch vessel atherosclerotic disease, or both. The upper thoracic aorta was involved in 36 of 43 patients (83.7%), and the left subclavian artery was involved in 14 of 43 patients (32.6%). Both the right subclavian artery and the brachiocephalic artery were involved in one of 43 patients (2.3%). Complicated carotid plaque was seen in 25 of 43 patients (58.1%).nnnCONCLUSIONnMRDTI can be applied in the detection of complicated plaque in the upper thoracic aorta and arch vessels. Complicated plaque was identified in 13% of the patient population. The upper thoracic aorta was the most common site involved. This technique could be useful for the screening of asymptomatic at-risk patients.

Clinical applicability of methods to measure carotid stenosis.

The North American (NASCET) and European (ECST) trials of carotid endarterectomy used discrepant methods to measure carotid stenosis on angiography. The aim of this study was to evaluate clinical applicability of currently available angiographic methods to measure carotid stenosis. Consecutive patients undergoing carotid angiography were evaluated. To estimate the normal internal carotid artery (ICA) bulb diameter on angiography, the common carotid artery (CCA) was used (ICA bulb diameter = 1.2 X CCA diameter measured 3-5 cm below the bifurcation) and the ICA diameter reduction was calculated: 1 - (d/1.2 X CCA) X 100%. We validated this against the planimetry of the intact removed plaque and termed it the Carotid Stenosis Index (CSI). The clinical applicability of NASCET, ECST, and CSI methods was then compared. Four observers evaluated 165 consecutive carotid angiograms performed over a 1-year period; 20% of arteries were normal, and 10% of ICAs were occluded. After these were excluded, the NASCET method was inapplicable in 30% of angiograms because of negative stenosis with minor degrees of atherosclerosis, inadequate views of the distal ICA, and two or more segments of distal ICA with parallel walls in which the diameters differed significantly. The ECST method gave an equivocal outline of the bulb in 10% of all angiograms. The CSI method was applicable in 97% of all angiograms, the major limitation being the presence of severe CCA atheroma (3%). The normal ICA bulb has -84% stenosis according to NASCET, whereas NASCET 0% stenosis equals 45-50% diameter reduction of ICA bulb and NASCET-positive stenoses cover only the last 50% of ICA stenoses. Although NASCET and ECST data are singularly irreplacable for surgical decisions, the angiographic methods used are discrepant from each other and of limited clinical applicability. This may affect the generalizibility of the results of these trials. CSI provides a firm scientific basis to make the results of the trials compatible.

Carotid near-occlusion can be identified with ultrasound by low flow velocity distal to the stenosis

Background Most carotid near-occlusions are indistinguishable from conventionalu2009≥u200950% stenosis on ultrasound, demonstrating high peak systolic velocity (PSV) in the stenosis. Purpose To study whether the velocity distal to the stenosis can separate high PSV near-occlusion from conventionalu2009≥u200950% stenosis. Material and Methods We included patients withu2009≥u200950% carotid stenosis with high PSV (≥125u2009cm/s), examined with both computed tomography angiography (CTA) and ultrasound within 30 days, and a distal velocity measurement was performed. Based on CTA, cases were divided into three groups: conventional stenosis; near-occlusion without full collapse (NwoC; normal-appearing albeit small distal artery); and near-occlusion with full collapse (NwC; threadlike distal artery). Distal Doppler ultrasound flow velocities were compared between these groups. Results Sixty patients were included: 33 patients with conventional stenosis; 20 patients with NwoC; and seven patients with NwC. Mean distal PSV was 93, 63, and 21u2009cm/s (Pu2009<u20090.001) and mean distal end-diastolic velocity was 30, 24, and 5u2009cm/s (Pu2009<u20090.001), respectively. A distal PSVu2009<u200950u2009cm/s was 63% sensitive and 94% specific for separating both types of near-occlusion from conventional stenosis. Conclusion In high PSV carotid stenoses, the distal velocity was lower in near-occlusions than conventional carotid stenosis. Distal velocities warrant further investigation in diagnostic studies.