CT evaluation of aberrant right subclavian artery: anatomy and clinical implications.

PurposeThe aim of the study was to perform CT angiography-based evaluation of aberrant right subclavian artery prevalence, anatomy, and its influence on clinical symptoms. METHODS: A total of 6833 patients who underwent 64-slice or dual-source CT angiography and those who revealed aberrant right subclavian artery underwent evaluation of its anatomy and were interviewed for the presence of clinical symptoms. RESULTS: Aberrant right subclavian artery was found in 32 (0.47%) patients consisting of 13 males and 19 females, with mean age of 60.8±13.4 years. Among the interviewed 30 (94%) patients, oesophageal compression was observed in 14 cases (47%) and tracheal compression in three cases (10%). None of the patients underwent surgery related to aberrant right subclavian artery. Dysphagia was the most common clinical symptom in nine cases (30%), and in those patients the median distance between aberrant right subclavian artery and trachea was lower (4 mm) than in individuals without dysphagia (7.5 mm) (p = 0.009). The median lumen area of the aberrant right subclavian artery at the level of oesophagus was higher in patients with dysphagia (208 mm2) compared with individuals without dysphagia (108 mm2) (p = 0.01). CONCLUSIONS: Aberrant right subclavian artery is a rare occurring abnormality in CT angiography. In the evaluated adult population, the most common symptom was dysphagia, which occurred in patients with decreased distance between aberrant right subclavian artery and trachea and increased lumen area of the aberrant artery at the level of compressed oesophagus.

Imaging modality-dependent carotid stenosis severity variations against intravascular ultrasound as a reference: Carotid Artery intravasculaR Ultrasound Study (CARUS).

PURPOSE: Different non-invasive and invasive imaging modalities are used to determine carotid artery stenosis severity that remains a principal parameter in clinical decision-making. We compared stenosis degree obtained with different modalities against vascular imaging gold standard, intravascular ultrasound, IVUS. METHODS: 300 consecutive patients (age 47-83 years, 192 men, 64% asymptomatic) with carotid artery stenosis of " ≥ 50%" referred for potential revascularization received as per study protocol (i) duplex ultrasound (DUS), (ii) computed tomography angiography (CTA), (iii) intraarterial quantitative angiography (iQA) and (iv) and (iv) IVUS. Correlation of measurements with IVUS (r), proportion of those concordant (within 10%) and proportion of under/overestimated were calculated along with recipient-operating-characteristics (ROC). RESULTS: For IVUS area stenosis (AS) and IVUS minimal lumen area (MLA), there was only a moderate correlation with DUS velocities (peak-systolic, PSV; end-diastolic, EDV; r values of 0.42-0.51, p < 0.001 for all). CTA systematically underestimated both reference area and MLA (80.4% and 92.3% cases) but CTA error was lesser for AS (proportion concordant-57.4%; CTA under/overestimation-12.5%/30.1%). iQA diameter stenosis (DS) was found concordant with IVUS in 41.1% measurements (iQA under/overestimation 7.9%/51.0%). By univariate model, PSV (ROC area-under-the-curve, AUC, 0.77, cutoff 2.6 m/s), EDV (AUC 0.72, cutoff 0.71 m/s) and CTA-DS (AUC 0.83, cutoff 59.6%) were predictors of ≥ 50% DS by IVUS (p < 0.001 for all). Best predictor, however, of ≥ 50% DS by IVUS was stenosis severity evaluation by automated contrast column density measurement on iQA (AUC 0.87, cutoff 68%, p < 0.001). Regarding non-invasive techniques, CTA was the only independent diagnostic modality against IVUS on multivariate model (p = 0.008). CONCLUSION: IVUS validation shows significant imaging modality-dependent variations in carotid stenosis severity determination.

Zotarolimus-eluting stent for the treatment of recurrent, severe carotid artery in-stent stenosis in the TARGET-CAS population.

PURPOSE: To evaluate the safety and efficacy of a balloon-mounted drug-eluting stent (DES) for recurrent carotid in-stent stenosis (ISS). METHODS: As part of our targeted carotid artery stenting (TARGET-CAS) protocol, neurological and ultrasound evaluations have been performed at 3, 6, and 12 months and then annually since 2001 in all carotid stent patients. For angiographically-confirmed >70% ISS, balloon angioplasty was performed as a first-line treatment. Recurrent ISS was treated with a 4.0-mm zotarolimus-eluting coronary stent (ZES) that was postdilated according to intravascular ultrasound imaging. Among the 1350 neuroprotected CAS procedures performed between January 2001 and March 2011, there were 7 (0.52%) patients (5 men; ages 51-72 years), all neurologically asymptomatic, with >70% recurrent ISS that occurred at 5 to 11 months after the initial balloon angioplasty treatment for ISS. RESULTS: ZES implantation under distal embolic protection was technically successful and uncomplicated. Angiographic stenosis was reduced from 84.6%±7.5% to 10.7%±3.6% (p<0.01). In 5 patients with ZES implanted fully within the self-expanding carotid stent, duplex ultrasound follow-up (mean 17 months, range 6-36) revealed no evidence of restenosis or stent fracture/deformation. In the 2 other patients, the ZES had been implanted for distal edge ISS such that the ZES protruded beyond the original carotid stent. This protruding segment of the ZES demonstrated deformation/kinking in both; in one, this led to symptomatic stent occlusion. CONCLUSION: The use of coronary ZES in the treatment of recurrent carotid ISS is feasible and appears effective provided the ZES is placed entirely within the original stent. Placement of a coronary ZES outside the carotid stent scaffold should be avoided.

Safety of embolic protection device-assisted and unprotected intravascular ultrasound in evaluating carotid artery atherosclerotic lesions.

BACKGROUND: Significant atherosclerotic stenosis of internal carotid artery (ICA) origin is common (5-10% at ≥ 60 years). Intravascular ultrasound (IVUS) enables high-resolution (120 µm) plaque imaging, and IVUS-elucidated features of the coronary plaque were recently shown to be associated with its symptomatic rupture/thrombosis risk. Safety of the significant carotid plaque IVUS imaging in a large unselected population is unknown. MATERIAL/METHODS: We prospectively evaluated the safety of embolic protection device (EPD)-assisted vs. unprotected ICA-IVUS in a series of consecutive subjects with ≥ 50% ICA stenosis referred for carotid artery stenting (CAS), including 104 asymptomatic (aS) and 187 symptomatic (S) subjects (age 47-83 y, 187 men). EPD use was optional for IVUS, but mandatory for CAS. RESULTS: Evaluation was performed of 107 ICAs (36.8%) without EPD and 184 with EPD. Lesions imaged under EPD were overall more severe (peak-systolic velocity 2.97 ± 0.08 vs. 2.20 ± 0.08 m/s, end-diastolic velocity 1.0 ± 0.04 vs. 0.7 ± 0.03 m/s, stenosis severity of 85.7 ± 0.5% vs. 77.7 ± 0.6% by catheter angiography; mean ± SEM; p<0.01 for all comparisons) and more frequently S (50.0% vs. 34.6%, p=0.01). No ICA perforation or dissection, and no major stroke or death occurred. There was no IVUS-triggered cerebral embolization. In the procedures of (i) unprotected IVUS and no CAS, (ii) unprotected IVUS followed by CAS (filters - 39, flow reversal/blockade - 3), (iii) EPD-protected (filters - 135, flow reversal/blockade - 48) IVUS + CAS, TIA occurred in 1.5% vs. 4.8% vs. 2.7%, respectively, and minor stroke in 0% vs. 2.4% vs. 2.1%, respectively. EPD intolerance (on-filter ICA spasm or flow reversal/blockade intolerance) occurred in 9/225 (4.0%). IVUS increased the procedure duration by 7.27 ± 0.19 min. CONCLUSIONS: Carotid IVUS is safe and, for the less severe lesions in particular, it may not require mandatory EPD use. High-risk lesions can be safely evaluated with IVUS under flow reversal/blockade.

Misclassification of carotid stenosis severity with area stenosis-based evaluation by computed tomography angiography: impact on erroneous indication to revascularization or patient (lesion) migration to a higher guideline recommendation class as per ESC/ESVS/ESO/SVS and CMS-FDA thresholds.

Intoduction: Despite a growing understanding of the role played by plaque morphology, the degree of carotid lumen reduction remains the principle parameter in decisions on revascularization in symptomatic and asymptomatic patients. Computed tomography angiography (CTA) is a widely used guideline-approved imaging modality, with "percent stenosis" commonly calculated as %area reduction (area stenosis - AS). Aim: We evaluated the impact of the non-linear relationship between diameter stenosis (DS) and AS (area = π • (diameter/2)2, so that in concentric lesions 51%AS is 30%DS and 75%AS is 50%DS) on stenosis severity misclassification using calculation of area reduction. Material and methods: CTA and catheter quantitative angiography (cQA) were performed in 300 consecutive patients referred to a tertiary vascular centre for potential carotid revascularization (age: 47-83 years, 33.7% symptomatic, 36% female; referral stenosis of ≥ "50%"). CTA-AS was determined by agreement of 2 experienced radiologists; cQA-DS (pivotal trials standard reference, NASCET method) was calculated by agreement of 2 corelab analysts. Results: For symptomatic lesion thresholds, CTA-AS-based calculation reclassified 76% of "< 50%" cQA-DS measurements to the "50-69%" group, and 58% of "50-69%" measurements to the "≥ 70%" group. For asymptomatic lesion thresholds, 78% of "< 60%" cQA-DS measurements were reclassified to the "60-79%" group, whereas 42% of "60-79%" cQA measurements crossed to the "≥ 80%" class. Overall, employing CTA-AS instead of cQA-DS enlarged the "60-79%" and "≥ 80%" lesion severity classes 1.6- and 5.8-fold, respectively, whereas the "≥ 70%" class increased 4.15-fold. Conclusions: Replacing the pivotal carotid trials reference standard cQA-DS "%stenosis" measurement with CTA-AS-based "%stenosis" results in a large-scale lesion/patient erroneous gain of an "indication" to revascularization or migration to a higher revascularization indication class. In consequence, unnecessary carotid procedures may be performed in the absence of cQA verification. Until guidelines rectify the "%stenosis" measurement methods with different guideline-approved imaging modalities (and, where needed, re-adjust decision thresholds), CTA-AS measurement should not be used as a basis for carotid revascularization.

Flow reversal for proximal neuroprotection during endovascular management of critical symptomatic carotid artery stenosis coexisting with ipsilateral external carotid artery occlusion.

PURPOSE: To report the utility of proximal brain protection by flow reversal in endovascular management of critical internal carotid artery (ICA) stenosis coexisting with ipsilateral external carotid artery (iECA) occlusion. CASE REPORT: Four patients with a symptomatic, critical ICA stenosis (in-stent restenosis in one) and iECA occlusion were admitted for carotid artery stenting (CAS). In all cases, the stenosis severity and high-risk lesion morphology precluded the use of filter protection. The "tailored" CAS algorithm indicated that a proximal anti-embolism system should be used to maximize the potential for effective neuroprotection. The flow reversal system, which consists of an independent guiding sheath balloon positioned in the common carotid artery (CCA) and an iECA balloon-wire, was employed, using the CCA balloon only. The system was well-tolerated, and the CAS procedures were uneventful. CONCLUSION: Due to a unique design with separate CCA and iECA balloons, the flow reversal system can be used for proximal neuroprotection during CAS in severe, symptomatic ICA lesions coexisting with iECA occlusion.

[Mounier-Kuhn syndrome (tracheobronchomegaly)]. / Zespól Mouniera-Kuhna (tracheobronchomegalia).

The case presents a 43 years old man, cigarette smoker, exposed to wood dust at work, with chronic, ineffective cough symptoms, limited physical exertion and recurring respiratory system infection. Disorders appeared at the age of 33 after severe double-sided pneumonia. Despite the lack of active clinical infection the following microorganisms: Pseudomonas aeruginosa and Staphylococcus aureus MSSA were isolated from patient bronchi mucus. Diagnosis followed image examination (CT, virtual bronchofibroscope). The following was recommended: quitting smoking, avoiding dust exposure at work, physiotherapy to ease mucus removal from bronchi and preventive vaccination. Tracheobronchomegaly consists in trachea clearance and central bronchi widening which disturbs air flow in air-passages and decreases cough effectiveness. Main symptoms are: paroxysmal cough, recurring bronchi inflammation and pneumonia resulting in mucus residing in air-passages.

Invasive treatment for carotid fibromuscular dysplasia.

INTRODUCTION: Fibromuscular dysplasia (FMD) is an infrequent non-inflamatory disease of unknown etiology that affects mainly medium-size arteries. The prevalence of FMD among patients scheduled for endovascular treatment of carotid artery stenosis is unknown. AIM: To evaluate the prevalence and treatment options of carotid FMD in patients scheduled for carotid artery stenting (CAS). MATERIAL AND METHODS: Between Jan 2001 and Dec 2013, 2012 CAS procedures were performed in 1809 patients (66.1% men; age 65.3 ±8.4 years, 49.2% symptomatic). In case of FMD suspicion in Doppler-duplex ultrasound (DUS), computed tomography angiography was performed for aortic arch and extracranial and intracranial artery imaging. For invasive treatment of FMD carotid stenosis, balloon angioplasty was considered first. If the result of balloon angioplasty was not satisfactory (> 30% residual stenosis, dissection), stent placement was scheduled. All patients underwent follow-up DUS and neurological examination 3, 6 and 12 months after angioplasty, then annually. RESULTS: There were 7 (0.4%) (4 symptomatic) cases of FMD. The FMD group was younger (47.9 ±7.5 years vs. 67.2 ±8.9 years, p = 0.0001), with higher prevalence of women (71.4% vs. 32.7%, p = 0.0422), a higher rate of dissected lesions (57.1% vs. 4.6%, p = 0.0002) and less severe stenosis (73.4% vs. 83.9%, p = 0.0070) as compared to the non-FMD group. In the non-FMD group the prevalence of coronary artery disease was higher (65.1% vs. 14.3% in FMD group, p = 0.009). All FMD patients underwent successful carotid artery angioplasty with the use of neuroprotection devices. In 4 cases angioplasty was supported by stent implantation. CONCLUSIONS: Fibromuscular dysplasia is rare among patients referred for CAS. In case of significant FMD carotid stenosis, it may be treated with balloon angioplasty (stent supported if necessary) with optimal immediate and long-term results.

Reversed blood flow during internal carotid artery stenting using Parodi Anti-Emboli System--progress in protection against cerebral stroke.

Carotid artery stenosis is one of the main causes of stroke. Nowadays two techniques for treating carotid stenosis are available - surgical endarterectomy and percutaneous angioplasty combined with stent implantation at the site of stenosis. Cerebral protection devices during internal carotid stenting significantly decrease the incidence of periprocedural complications, however, during the introduction of protective devices the cerebral blood flow remains unprotected. Therefore, the quest for a system specifically protecting cerebral flow during the whole procedure is still underway. Temporary reversal of carotid flow during the procedure using the Parodi Anti-Emboli System seems a viable solution. The present study describes the first two patients who underwent internal carotid artery stenting using this technique in our institution.

[Carotid artery stenting with proximal or distal brain protection: early outcome]. / Wczesne wyniki stentowania tetnic szyjnych z zastosowaniem systemów czasowej protekcji mózgu.

BACKGROUND: Stroke is the third cause of death and a leading cause of disability. Significant atherosclerotic carotid artery stenosis is associated with as many as one in five strokes. Recent randomized trials have shown that percutaneous carotid artery stenting (CAS) is at least as effective and safe as surgery. AIM: To evaluate the early outcome of CAS performed with brain protection systems in a large series of consecutive patients. METHODS: From January 2001 to April 2004, 132 patients (age 63 +/- 8 years, 99 symptomatic and 90 with co-existing coronary artery disease, 36 women) with carotid artery stenosis were treated in our Institution. All patients underwent independent neurological assessment and non-invasive imaging (extra- and intracranial duplex Doppler and CT angiography, brain CT) before the procedure to tailor the brain protection system to the patient and lesion. Proximal (Parodi Anti-Emboli System, Mo.Ma) or distal (Percusurge/Guardwire, filters i.e. Angioguard, EPI FilterWire, Accunet, Spider, NeuroShield) neuroprotection was applied respectively in 42 (31%) and 93 (69%) cases. Clinical evaluation was performed on discharge and at 30 days. RESULTS: Procedural success rate was 130/132 (98.6%). The degree of stenosis (expressed as % diameter reduction, QCA) decreased from 76.3 +/- 10.6 to 16.9 +/- 9.1 (p < 0.001) while the minimal lumen diameter increased from 1.48 +/- 0.67 to 3.72 +/- 0.71 mm (p < 0.001). In the peri-procedural period, 5 (3.7%) patients had TIA and 1 (0.7%) had hyperperfusion syndrome with a small haemorrhagic stroke, but with a complete clinical recovery. There were no deaths, myocardial infarctions nor any major strokes. On discharge no patients had neurological deterioration as compared to the admission status. At 30 days there were no new cardiac or neurological events. CONCLUSIONS: Our results show that percu-taneous CAS--when performed with brain protection--has a high success rate and a very low complication rate. It is conceivable that the patient/lesion-tailored application of a particular neuroprotection system importantly contributes to the favourable early outcome of CAS.

Methodology and evaluation of the renal arterial system.

INTRODUCTION: The broad range of medical images and image processing technologies are applied in urology. The aim was to propose methodology to assess three-dimensional (3D) arrangement of renal arterial tree and to build a statistical model for analyzing the layout of arteries in the sections of the kidney. METHODS: The series of kidney CT slices are analyzed using image processing procedures and further the 3D model of arterial systems is converted to a graph tree which includes information about features of the renal arterial system. RESULTS: The selected endocast was transformed to the form of the 3D connected tubes, further to the tree data structure and next analyzed. The information about 3D coordinates of the nodes, also branch length and diameter were stored. Renal arterial system of the considered kidney possessed 181 branches with 14 bifurcation levels. The number of branches was highest at the 9th bifurcation level. The mean length of the arterial branch on each bifurcation level was constant (6 mm). The branch diameters rapidly decreased after each bifurcation. The number of terminal branches increases up to 9th level where there are 19 terminal branches. The mean length of terminal arteries was 7.17 mm while the mean radius 0.46 mm. A statistically significant correlation between parameters that described sub-trees was noticed. It was observed that the individual artery segments occupy a separate space in the kidney volume. CONCLUSIONS: The methodology has the potential to assist in presurgical planning based on branching patterns of the renal arterial system and corresponding pathology.

Carotid artery stenting with patient- and lesion-tailored selection of the neuroprotection system and stent type: early and 5-year results from a prospective academic registry of 535 consecutive procedures (TARGET-CAS).

PURPOSE: To develop and prospectively evaluate the safety and efficacy of an algorithm for tailoring neuroprotection devices (NPD) and stent types to the patient/lesion in carotid artery stenting (CAS). METHODS: From November 2002 to October 2007, 499 patients (360 men; mean age 65.2+/-8.4 years, range 36-88) were prospectively enrolled in a safety and efficacy study of tailored CAS using proximal (flow blockade or reversal) or distal (filters or occlusion) NPDs and closed- or open-cell self-expanding stents. Of the 535 lesions treated in the study, 175 (32.7%) were "high risk" by morphology. Half (50.1%) the patients were symptomatic. RESULTS: A quarter (137, 25.6%) of the procedures were performed under proximal protection and the remainder (398, 74.4%) with distal NPDs; the direct stenting rate was 66.9%. High-risk lesions were treated predominantly with a proximal NPD and closed-cell stent (77.1% and 82.9%, respectively) and less frequently by direct stenting (37.1%, p<0.0001 versus non-high-risk lesions). The in-hospital death/stroke rate was 2.0% (95% CI 0.85% to 3.23%), and the death/major stroke rate was 0.7% (95% CI 0.02% to 1.48%). There were no myocardial infarctions, but there was 1 (0.2%) further death within 30 days. With the tailored approach, symptom status and high-risk lesion morphology were not risk factors for an adverse outcome after CAS; only age >75 years (p<0.001) was a predictor of short-term death. Long-term survival (95.4% at 1 and 88.3% at 5 years) was similar for symptomatic versus asymptomatic patients, direct stenting versus predilation, and closed- vs. open-cell stent design; only coronary artery disease adversely impacted survival (p = 0.04). The rates of freedom from death/ipsilateral stroke were 94.9% at 1 year and 85.9% at 5 years. CONCLUSION: Tailored CAS is associated with a low complication rate and high long-term efficacy. CAS operators should have a practical knowledge of different NPDs, including at least one proximal type.

Subarachnoid hemorrhage after carotid artery stenting.

We describe subarachnoid hemorrhage (SAH) in a 66-year-old man, who underwent technically successful carotid stenting for a string-stenosis of the right internal carotid artery (ICA) in a presence of contralateral ICA occlusion with recurrent right hemisphere transient ischemic attacks. At 2 hours, the patient developed headache and vomiting, but no focal neurological deficits. Performed transcranial color-coded Doppler (TCCD) showed over 2.8-fold increase of the peak systolic velocity in the right middle cerebral artery. The emergent CT of the brain showed SAH with the right hemisphere edema. Patient was treated with Nimodipine in continuous infusion, diuretics i.v. and additional hypotensive therapy depending on blood pressure values. Clopidogrel was stopped for 5 days. Over next 4 weeks, a gradual cerebral velocities decrease was observed on TCCD, which was related to clinical and CT resolution.

Assessment of flow changes in the circle of Willis after stenting for severe internal carotid artery stenosis.

PURPOSE: To assess flow velocities in the cerebral arteries after carotid artery stenting (CAS) in patients with unilateral versus bilateral lesions and analyze velocities in patients with neurological complications after CAS. METHODS: Ninety-two patients (68 men; mean age 63.2 +/- 8.4 years, range 44-82) with internal carotid artery (ICA) stenoses were divided according to unilateral (group I, n = 72) or bilateral (group II, n = 20) disease. Fifty age- and gender-matched patients without lesions in the extra- or intracranial arteries served as a control group. Transcranial color-coded Doppler ultrasound was performed prior to and within 24 hours after CAS in the test groups; systolic velocities were assessed ipsilateral (i) and contralateral (c) to the CAS site in the middle cerebral artery (MCA) and anterior cerebral artery (ACA). RESULTS: Collateral flow via the anterior communicating artery (ACoA) was found in all group-II patients and 90% of group-I patients. After CAS, collateral flow through the ACoA ceased, and the velocity increased by 26% in the iMCA in group I compared to controls (p < 0.001). In group II, iMCA flow increased by 30% (p < 0.001) and flow via the ACoA (p < 0.001) increased, resulting in normalization of cMCA velocities (p = 0.928). In 89 (96.7%) subjects, CAS was uncomplicated. Hyperperfusion syndrome occurred in 2 (2.2%) patients, both with bilateral ICA stenoses; 1 (1.1%) transient ischemic attack was seen in a patient with unilateral disease. In the patients with hyperperfusion syndrome, the MCA velocities were 2.7- and 7.4-fold higher, respectively, versus before CAS and 2-fold higher than in controls. CONCLUSION: Uncomplicated CAS results in an iMCA velocity increase >25% compared to controls. MCA velocities in hyperperfusion syndrome were greatly increased versus before CAS and in controls.