Stem cell factor protects against chronic ischemic retinal injury by modulating on neurovascular unit

Retinal ischemia is a significant factor in various vision-threatening diseases, but effective treatments are currently lacking. This study explores the potential of stem cell factor (SCF) in regulating the neurovascular unit as a therapeutic intervention for retinal ischemic diseases. A chronic retinal ischemia model was established in Brown Norway rats using bilateral common carotid artery occlusion (BCCAO). Subsequent SCF treatment resulted in a remarkable recovery of retinal function, as indicated by electroretinogram, light/dark transition test, and optokinetic head tracking test results. Histological examination demonstrated a significant increase in the number of retinal neurons and an overall thickening of the retina. Immunofluorescence confirmed these findings and further demonstrated that SCF treatment regulated retinal remodeling. Notably, SCF treatment ameliorated the disrupted expression of synaptic markers in the control group's BCCAO rats and suppressed the activation of Müller cells and microglia. Retinal whole-mount analysis revealed a significant improvement in the abnormalities in retinal vasculature following SCF treatment. Transcriptome sequencing analysis revealed that SCF-induced transcriptome changes were closely linked to the Wnt7 pathway. Key members of the Wnt7 pathway, exhibited significant upregulation following SCF treatment. These results underscore the protective role of SCF in the neurovascular unit of retinal ischemia rats by modulating the Wnt7 pathway. SCF administration emerges as a promising therapeutic strategy for retinal ischemia-related diseases, offering potential avenues for future clinical interventions.

Asymmetric deep cerebral venous filling predicts poor outcome of acute basilar artery occlusion after endovascular treatment

OBJECTIVE

To explore the relationship between asymmetric deep cerebral venous (ADCV) filling and poor outcomes after endovascular treatment (EVT) in patients with acute basilar artery occlusion (ABAO).

METHODS

ABAO patients were selected from a prospectively collected data at our center. The DCV filling was evaluated using computed tomography perfusion (CTP)-derived reconstructed 4D-DSA or mean venous map. ADCV filling was defined as the internal cerebral vein (ICV), thalamostriate vein (TSV), or basal vein of Rosenthal (BVR) presence of ipsilateral filling defects or delayed opacification compared to the contralateral side. Poor prognosis was defined as a modified Rankin scale score >3 at the 90-day follow-up.

RESULTS

A total of 90 patients were enrolled in the study, with a median Glasgow Coma Scale of 6, 46 (51.1%) showed ADCV filling, 59 (65.6%) had a poor prognosis, and 27 (30.7%) had malignant cerebellar edema (MCE). Multivariate adjusted analysis revealed significant associations between asymmetric TSV and poor prognosis (odds ratio, 9.091, p = 0.006); asymmetric BVR (OR, 9.232, p = 0.001) and asymmetric ICV (OR, 4.028, p = 0.041) were significantly associated with MCE.

CONCLUSION

Preoperative ADCV filling is an independent influencing factor for the poor outcome after EVT in ABAO patients.

Multiomics Data Integration Identifies New Molecular Signatures for Abdominal Aortic Aneurysm and Aortic Occlusive Disease: Implications for Early Diagnosis, Prognosis, and Therapeutic Targets

Cardiovascular disease (CVD) is the leading cause of death among adults in developed countries. Among CVDs, abdominal aortic aneurysm (AAA) and aortic occlusive disease (AOD) are of great public health importance because of the high mortality rate in the elderly population. Despite significant molecular insights into AAA and AOD, the molecular mechanisms of these diseases remain unclear, and the current lack of robust diagnostic and prognostic biomarkers requires novel approaches to biomarker discovery and molecular targeting. In this study, we performed a comparative analysis of genome-wide expression data from patients with large AAA (n = 29), small AAA (n = 20), AOD (n = 9), and controls (n = 10). Specifically, we identified the differentially expressed genes and associated molecular pathways and biological processes (BPs) in each disease. Using a systems science approach, these data were linked to comprehensive human biological networks (i.e., protein-protein interaction, transcriptional regulatory, and metabolic networks) to identify molecular signatures of the salient mechanisms of AAA and AOD. Significant alterations in lipid metabolism and valine, leucine, and isoleucine metabolism, as well as neurodegenerative diseases and sex differences in the pathogenesis of AAA and AOD were identified. In the presence of aneurysm, size-dependent changes in lipid metabolism were observed. In addition, molecules and signaling pathways related to immunity, inflammation, infectious disease, and oxidative phosphorylation were identified in common. The results of the comparative and integrative analyzes revealed important clues to disease mechanisms and reporter molecules at various levels that warrant future development as potential prognostic biomarkers and putative therapeutic targets.

Adventitial Microcirculation Is a Major Target of SARS-CoV-2-Mediated Vascular Inflammation

We report the case of a 77-year-old woman affected by coronavirus disease-19 (COVID-19) who developed an occlusive arterial disease of the lower limb requiring a left leg amputation. We studied the mechanisms of vascular damage by SARS-CoV-2 by means of a comprehensive multi-technique in situ analysis on the diseased popliteal arterial district, including immunohistochemistry (IHC), transmission electron microscopy (TEM) and miRNA analysis. At histological analyses, we observed a lymphocytic inflammatory infiltrate, oedema and endothelialitis of adventitial vasa vasorum while the media was normal and the intima had only minor changes. The vasa vasorum expressed the ACE2 receptor and factor VIII; compared with the controls, VEGFR2 staining was reduced. TEM analyses showed endothelial injury and numerous Weibel–Palade bodies in the cytoplasm. No coronavirus particle was seen. IL-6 protein and mRNA, together with miR-155-5p and miRs-27a-5p, which can target IL-6, were significantly increased compared with that in the controls. Our case report suggests an involvement of adventitial artery microcirculation by inflammation in the course of COVID-19. Without evident signs of current infection by SARS-CoV-2, endothelial cells show a spectrum of structural and functional alterations that can fuel the cardiovascular complications observed in people infected with SARS-CoV-2.

Endovascular treatment combined with vertebral artery endarterectomy for patients with acute tandem vertebrobasilar artery occlusion

PURPOSE

To evaluate the safety and efficacy of endovascular treatment combined with vertebral artery endarterectomy in patients with acute tandem vertebrobasilar artery occlusion.

METHODS

From April 2017 to March 2019, three patients with acute basilar artery occlusion combined with ostial vertebral occlusion in our institution were enrolled in the study. They underwent endovascular treatment combined with vertebral artery endarterectomy. The clinical, technical and functional outcomes of the patients were retrospectively analysed.

RESULTS

All three patients in the study underwent complete recanalization. The modified Thrombolysis in Cerebral Infarction (mTICI) grade was 2b/3 in all patients. The modified Rankin Scale (mRS) score was 0-2 for the three patients at 3 months. Follow-up CT scans revealed no cerebral haemorrhage, and no patients died during follow-up. All patients achieved good clinical outcomes after the combined treatment.

CONCLUSION

Endovascular treatment combined with vertebral artery endarterectomy is a feasible method to treat patients with acute basilar artery occlusion combined with ostial vertebral occlusion, especially when the guidewire cannot pass through the ostium of the dominant vertebral artery occlusion.

Fufang-Zhenzhu-Tiaozhi capsule ameliorates rabbit's iliac artery restenosis by regulating adiponectin signaling pathway

BACKGROUND AND PURPOSE

Fufang-Zhenzhu-Tiaozhi Capsule (FTZ), a traditional Chinese medicine, has been shown obvious effects on the treatment of dyslipidemia and atherosclerosis. The aim of this study was to evaluate whether FTZ can ameliorate rabbit iliac artery restenosis after angioplasty by regulating adiponectin signaling pathway.

EXPERIMENTAL APPROACH

The rabbit iliac artery restenosis model was established through percutaneous iliac artery transluminal balloon angioplasty and a high-fat diet. Twenty eight male New Zealand rabbits (8-week-old) were divided into sham operation group (Group Ⅰ), model group (Group Ⅱ), atorvastatin group (Group Ⅲ) and FTZ group (Group Ⅳ), with 7 rabbits in each group. Vascular stenosis was analyzed with Digital Subtraction Angiography. Level of adiponectin (APN), and inflammatory factor including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) as well as monocyte chemoattractant protein-1 (MCP-1) was measured by Enzyme Linked Immunosorbent Assay; and injured iliac artery was collected for Hematoxylin-eosin staining and Western Blotting detection of expression of peroxisome proliferator-activated receptor-alpha (PPAR-α), adenosine 5'-monophosphate -activated protein kinase (AMPK) and phosphorylated adenosine 5'-monophosphate -activated protein kinase (p-AMPK). Besides, we evaluated FTZ's safety for the first time.

KEY RESULTS

Percutaneous iliac artery transluminal balloon angioplasty and high-fat diet result in inflammatory response and restenosis. Compared with Group Ⅱ, iliac artery restenosis was significantly ameliorated in Group Ⅳ (P < 0.05). Treated with FTZ, serum lipids were significantly decreased (P < 0.01), while the level of APN was elevated significantly (P < 0.01). Western blotting detection of the injured iliac artery showed that the expressions of PPAR-α, AMPK and p-AMPK were significantly increased in Group Ⅳ (P < 0.01) than that in Group Ⅱ. Besides, before and after taking drugs, liver and kidney function indicators, creatine kinase, as well as measurement of echocardiography were of no statistical difference in four groups(P > 0.05).

CONCLUSIONS AND IMPLICATIONS

FTZ could effectively reduce serum lipids and ameliorate rabbit's iliac artery restenosis after angioplasty, and its mechanism may be related to activation of APN signaling pathway.

Incidental Detection of Iliac Artery Occlusion on 3-Phase Bone Scintigraphy

Our patient was a 72-year-old man with absent activity of the right femoral artery and mildly decreased Tc-DPD activity on the right leg as indicated on the blood pool and delayed images, respectively. Subsequent peripheral angiography revealed a total occlusion of the right external iliac artery with good collateral flow. Careful review of blood flow and blood pool images of 3-phase bone scintigraphy could provide additional information about peripheral vascular disease.

Heart-Shaped Bilateral Medullary Pyramidal Infarction as a Pathognomonic Finding of Anterior Spinal Artery Occlusion

BACKGROUND

Unilateral anterior spinal artery (ASA) occlusion resulting in bilateral medullary pyramidal (BMP) infarction is a rare and devastating stroke subtype. We present two cases highlighting the diagnostic and clinical challenges of BMP infarction.

METHODS

Case reports and literature review.

RESULTS

A 57-year-old man rapidly had severe vomiting and diarrhea 2 h after a meal. Examination revealed bulbar weakness and areflexic tetraplegia. Respiratory failure developed, requiring intubation and mechanical ventilation. Brain magnetic resonance imaging (MRI) showed a heart-shaped region of diffusion abnormality, characteristic of BMP infarction. Cerebral angiography showed an occluded left vertebral artery with unilateral left-sided origin of ASA. The patient required tracheostomy and percutaneous gastrostomy tube and was discharged to rehabilitation, with little improvement of his tetraplegia at 3-month follow-up. A 43-year-old woman presented to the emergency department with acute onset of lower-extremity paresthesia and history of upper respiratory infection 2 weeks prior. Initial examination findings included bulbar weakness, dysphagia, hyporeflexia, and generalized weakness. After admission, she had severe respiratory distress and required intubation. Lumbar puncture was evaluated for Guillain-Barré syndrome, but cerebrospinal fluid protein concentration was normal. Changes on diffusion-weighted MRI of the brain showed the characteristic heart-shaped BMP infarction, indicating occlusion of a unilateral ASA. She required tracheostomy and percutaneous gastrostomy tube placement, with no paralysis resolution.

CONCLUSION

Acute BMP infarction may present with flaccid tetraplegia mimicking neuromuscular disorders. When the infarction is recognized early, intravenous thrombolysis can be considered to reduce morbidity of this rare stroke subtype.

Comparison between paclitaxel-coated balloon and standard uncoated balloon in the treatment of femoropopliteal long lesions in diabetics

Atherosclerotic diseases may include femoropopliteal artery stenosis or occlusion. Percutaneous transluminal angioplasty (PTA) is an effective and minimally invasive treatment strategy for atherosclerotic femoropopliteal artery stenosis/occlusion disease. Balloon angioplasty is a widely used technique in the management of occlusive disease in almost all arterial segments.We enrolled 111 diabetics with long femoropopliteal lesions, among which 54 received PTA with paclitaxel-coated balloon (the Paclitaxel group), and 57 with standard balloon catheters (the Control group).The primary outcome was set as angiographic late lumen loss (LLL) within 6 months; the secondary angiographic outcome was binary restenosis. Clinical outcomes included Rutherford clarification, ankle-brachial index (ABI) and rate of clinically driven target lesion revascularization (TLR). Two groups had similar basal clinical features, angiographic and procedural characteristics. Compared to controls, the Paclitaxel group had a significantly lower 6-month LLL rate, 12-month binary restenosis rate, 12-month TLR, lower Rutherford grades at 3 and 6 months, and higher ABI at 3 months. For all factors which might influence outcomes, fasting blood glucose was negatively correlated with ABI; the blood urea nitrogen (BUN) was positively related with the Rutherford clarification grades. In addition, the coronary heart disease (CHD) and smoking histories were positively correlated with residual stenosis after treatment.Collectively, the paclitaxel-coated balloon angioplasty can yield more favorable angiographic and clinical outcomes than standard uncoated balloon angioplasty, even in the more challenging lesions (the long and occlusive femoropopliteal lesions) in diabetics, when it had a similar safety profile to the traditional balloon. Blood glucose, BUN, CHD, and smoking imply poor curative effects.

FLAIR vascular hyperintensity in acute stroke is associated with collateralization and functional outcome

PURPOSE

Fluid-attenuated inversion recovery vascular hyperintensity (FVH) is frequently found in stroke patients after intracranial arterial occlusion, but the prognostic value of FVH findings is unclear. We assessed whether FVH is associated with cerebral collateral status and functional outcome in patients with acute stroke patients receiving endovascular therapy.

METHODS

FVH score, American Society of Interventional and Therapeutic Neuroradiology (ASITN) grade, the functional outcome at 3 months (modified Rankin Scale (mRS)), and other clinical data were collected for 37 acute stroke patients with large vessel occlusion (LVO) receiving MRI before and after endovascular therapy. Statistical analysis was performed to predict functional outcome after stroke.

RESULTS

The good functional outcome group (n = 16) had a higher FVH₁ (FVH before therapy) score (4.63 ± 1.20 vs 3.14 ± 1.15; p = 0.001) and ASITN grade (3.31 ± 0.48 vs 2.00 ± 1.22; p < 0.001) and a lower FVH₂ (FVH after therapy) score than the poor functional outcome group (n = 21; 0.125 ± 0.50 vs 1.44 ± 2.16; p = 0.030). mRS at 3 months was negatively correlated with FVH₁ (r = - 0.525, p = 0.001) and the ASITN grade (r = - 0.478, p = 0.003) and positively correlated with FVH₂ (r = 0.376, p = 0.034). FVH₁ (OR, 0.085; 95% CI, 0.013-0.577; p = 0.012) and FVH₂ (OR, 2.724; 95% CI, 1.061-6.996; p = 0.037) were independently associated with functional outcome in multivariable logistic regression analysis.

CONCLUSIONS

Assessing FVH before and after therapy in acute stroke patients with LVO might be useful for predicting functional outcome after stroke.

KEY POINTS

• Fluid-attenuated inversion recovery vascular hyperintensity is a circular or serpentine brightening in the brain parenchyma or cortical surface bordering the subarachnoid space on MR imaging. • A prospective study showed that fluid-attenuated inversion recovery vascular hyperintensity is associated with cerebral collateral circulation and prognosis. • Fluid-attenuated inversion recovery vascular hyperintensity helps clinicians to predict the prognosis of patients with acute stroke.

The Role of Adipokines in Surgical Procedures Requiring Both Liver Regeneration and Vascular Occlusion

Liver regeneration is a perfectly calibrated mechanism crucial to increase mass recovery of small size grafts from living donor liver transplantation, as well as in other surgical procedures including hepatic resections and liver transplantation from cadaveric donors. Regeneration involves multiple events and pathways in which several adipokines contribute to their orchestration and drive hepatocytes to proliferate. In addition, ischemia-reperfusion injury is a critical factor in hepatic resection and liver transplantation associated with liver failure or graft dysfunction post-surgery. This review aims to summarize the existing knowledge in the role of adipokines in surgical procedures requiring both liver regeneration and vascular occlusion, which increases ischemia-reperfusion injury and regenerative failure. We expose and discuss results in small-for-size liver transplantation and hepatic resections from animal studies focused on the modulation of the main adipokines associated with liver diseases and/or regeneration published in the last five years and analyze future perspectives and their applicability as potential targets to decrease ischemia-reperfusion injury and improve regeneration highlighting marginal states such as steatosis. In our view, adipokines means a promising approach to translate to the bedside to improve the recovery of patients subjected to partial hepatectomy and to increase the availability of organs for transplantation.

Mathematical modelling of cardiac pulse wave reflections due to arterial irregularities

This research aims to model cardiac pulse wave reflections due to the presence of arterial irregularities such as bifurcations, stiff arteries, stenoses or aneurysms. When an arterial pressure wave encounters an irregularity, a backward reflected wave travels upstream in the artery and a forward wave is transmitted downstream. The same process occurs at each subsequent irregularity, leading to the generation of multiple waves. An iterative algorithm is developed and applied to pathological scenarios to predict the pressure waveform of the reflected wave due to the presence of successive arterial irregularities. For an isolated stenosis, analysing the reflected pressure waveform gives information on its severity. The presence of a bifurcation after a stenosis tends do diminish the amplitude of the reflected wave, as bifurcations' reflection coefficients are relatively small compared to the ones of stenoses or aneurysms. In the case of two stenoses in series, local extrema are observed in the reflected pressure waveform which appears to be a characteristic of stenoses in series along an individual artery. Finally, we model a progressive change in stiffness in the vessel's wall and observe that the less the gradient stiffness is important, the weaker is the reflected wave.

In Hyperacute Recanalization Therapy, Early Hospital Arrival Improves Outcome in Patients with Large Artery Occlusion

BACKGROUND

It is unknown whether the effect of onset---to-door (OTD) time on clinical outcomes differs between -patients with and without large artery occlusion (LAO) who undergo hyperacute recanalization therapy.

METHODS

Hyperacute recanalization therapy includes intravenous thrombolysis tissue-plasminogen activator (tPA), and endovascular therapy (EVT). Favorable clinical outcome was defined as modified Rankin Scale of ≤2 at discharge.

RESULTS

Among 164 patients, 117 (71%) patients received tPA, 86 (52%) received EVT, and 39 (24%) received tPA and EVT. One hundred and fifteen patients (70%) were classified into the LAO group and 49 (30%) into the non-LAO group. In the total cohort, multivariate regression analysis showed OTD time (OR 0.809 [95% CI 0.693-0.944], p = 0.007) was an independent factor related to the favorable outcome. Similarly, among patients with LAO, OTD was an independent negative factor for the favorable outcome (0.779 [0.646-0.940], p = 0.009). On the contrary, OTD was not associated with the favorable outcome (1.5 [0.7-2.5] vs. 1.7 [1.1-3.2], p = 0.155) in patients without LAO. This was confirmed with multivariate regression analysis, which did not show OTD to be an independent factor for the favorable outcome (0.900 [0.656-1.236], p = 0.516).

CONCLUSION

The effect of early hospital arrival on clinical outcome differed between patients with and without LAO.

Tardus parvus waveforms in Doppler ultrasonography for hepatic artery stenosis after liver transplantation: can a new cut-off value guide the next step?

PURPOSE

Considering the high false-positive diagnosis of the tardus parvus waveform (TPW) in Doppler ultrasonography (DUS) for hepatic artery stenosis (HAS) after liver transplantation (LT), this study aimed to determine clinical features and new cut-off values to help guide treatment.

MATERIALS AND METHODS

This retrospective study was approved by an Institutional Review Board. A total of 171 LT recipients were included and underwent DUS and either computed tomography angiography or digital subtraction angiography with an interval < 4 weeks at least 1 month post-LT. The DUS of 69 patients exhibited TPW [defined as resistive index (RI) < 0.5 and systolic acceleration time (SAT) > 0.08 s]. A multilevel likelihood ratio (LR) analysis was used to explore new cut-off values for DUS. In addition, abnormal liver function was considered additional evidence (defined as any liver enzyme > 3-fold of the upper limit of normal level or 2-fold increased). The results were stratified into three categories, category 1 (subjects with traditional TPW), category 2 (subjects with traditional TPW and abnormal liver function), and category 3 (subjects with traditional TPW and abnormal liver function, or with new cut-off values), and the diagnostic performance of each category was analyzed.

RESULTS

The LR analysis revealed new cut-off values of RI < 0.4 (LR = 10.58) or SAT > 0.12 s (LR = 16.46). The false-positive rates for categories 2 and 3 were significantly lower (7.6% vs. 18.1%, P = 0.038; 1.9% vs. 18.1%, P < 0.001, respectively) than those for category 1, while the sensitivity for category 2 was significantly lower (41.8% vs. 74.6%, P < 0.001; 41.8% vs. 61.2%, P = 0.038, respectively) than that for categories 1 and 3.

CONCLUSION

Using either (1) RI < 0.4 or SAT > 0.12 s, or (2) traditional TPW (RI < 0.5 and SAT > 0.08 s) in the presence of abnormal liver functions as the DUS criteria for HAS will significantly decrease the false-positive rate compared to traditional TPW without a significant increase in the false-negative rate.

Clinical associations of microvascular obstruction and intramyocardial hemorrhage on cardiovascular magnetic resonance in patients with acute ST segment elevation myocardial infarction (STEMI): An observational cohort study

Acute myocardial infarction (AMI) is recognized as being a life-threatening event. Both microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH) have been recognized as poor prognostic factors in myocardial infarct (MI) since they adversely affect left ventricular remodeling. MVO refers to small vessels changes that prevent adequate tissue perfusion despite revascularization whereas IMH is a severe form of MVO. A limited number of studies have demonstrated the segmental intervention time and the clinical factors in the presence of MVO and IMH. Therefore, we aimed in this study to determine the correlations of the intervention-associated and clinical indexes with malignant cardiovascular magnetic resonance (CMR) signs in patients with AMI.Sixty-three patients with STEMI who underwent primary percutaneous coronary intervention (PPCI) within 12 hours were included in this study. A 3.0-T CMR scan was prescribed, and the subsequent image analysis was conducted by researchers blinded to the clinical index results. Late-gadolinium enhancement (LGE) and T2* sequences were mainly used for MVO and IMH identification and quantification.Patients exhibiting both MVO and IMH had the highest level of LGE (P < .001) and were significantly more frequently assigned to a pre-PPCI thrombolysis in myocardial infarction (TIMI) flow class of 0 (n=25, 89.3%). The MVO size correlated positively with the IMH size (r = 0.81, P < .01). A pre-PPCI TIMI flow class of 0 was found to reliably predict the presence of IMH (P < .001). Patients who received the intervention 4 to 6 hours after MI onset were more likely to exhibit MVO and IMH, although this trend was not statistically significant.We showed in our study that both MVO and IMH correlated with the degree of AMI and the pre-PPCI coronary flow, and both tended to occur more frequently in cases involving an interval of 4 to 6 hours between the onset of MI and the intervention. CMR is a reliable method for assessing MVO and IMH and its imaging features following gadolinium administration are characteristic. These findings stress the importance of using CMR in evaluating and improving the outcome of the medical management.

Multiple intracranial aneurysms and abdominal aortic occlusion in a young woman: A case report

RATIONALE

Multiple intracranial aneurysms occur in 10% to 30% patients with cerebral aneurysms.

PATIENT CONCERNS

We reported a case of multiple intracranial aneurysms concurrent with abdominal aortic occlusion (AAO) in a 29-year-old woman was admitted because of abrupt onset of severe headache, vomiting, and dizziness for 26 hours. She complained sudden onset of severe headache, vomiting, and dizziness.

DIAGNOSES

Head computed tomography (CT) angiogram revealed 2 aneurysms of the anterior communicating artery (ACA) and a third aneurysm at the right middle cerebral artery (MCA). A diagnosis of multiple intracranial aneurysms concurrent with abdominal aortic occlusion (AAO) was made.

INTERVENTIONS

We clipped the 2 aneurysms at the ACA via a right pterional approach. The transfemoral approach failed because of an unsuspected AAO. A right carotid artery approach was then employed to embolize the aneurysm at the right MCA with three coils.

OUTCOMES

Magnetic resonance angiography (MRA) at 7 days after the embolization demonstrated complete disappearance of all the intracranial aneurysms, but AAO was still present. The patient remained asymptomatic during 5-years of follow-up.

LESSONS

The case highlights the importance of a thorough physical examination, and in rare cases, AAO or other abdominal aortic abnormalities should be considered in young nonsmoking females. Successful treatment can be achieved by aneurysm clipping and embolization.

Ixonnexin from Tick Saliva Promotes Fibrinolysis by Interacting with Plasminogen and Tissue-Type Plasminogen Activator, and Prevents Arterial Thrombosis

Tick saliva is a rich source of modulators of vascular biology. We have characterized Ixonnexin, a member of the "Basic-tail" family of salivary proteins from the tick Ixodes scapularis. Ixonnexin is a 104 residues (11.8 KDa), non-enzymatic basic protein which contains 3 disulfide bonds and a C-terminal rich in lysine. It is homologous to SALP14, a tick salivary FXa anticoagulant. Ixonnexin was produced by ligation of synthesized fragments (51-104) and (1-50) followed by folding. Ixonnexin, like SALP14, interacts with FXa. Notably, Ixonnexin also modulates fibrinolysis in vitro by a unique salivary mechanism. Accordingly, it accelerates plasminogen activation by tissue-type plasminogen activator (t-PA) with Km 100 nM; however, it does not affect urokinase-mediated fibrinolysis. Additionally, lysine analogue ε-aminocaproic acid inhibits Ixonnexin-mediated plasmin generation implying that lysine-binding sites of Kringle domain(s) of plasminogen or t-PA are involved in this process. Moreover, surface plasmon resonance experiments shows that Ixonnexin binds t-PA, and plasminogen (KD 10 nM), but not urokinase. These results imply that Ixonnexin promotes fibrinolysis by supporting the interaction of plasminogen with t-PA through formation of an enzymatically productive ternary complex. Finally, in vivo experiments demonstrates that Ixonnexin inhibits FeCl3-induced thrombosis in mice. Ixonnexin emerges as novel modulator of fibrinolysis which may also affect parasite-vector-host interactions.

Adventitial Cystic Disease Communicating with the Knee Joint: A Case Report with Histopathological Study of the Connection

Adventitial cystic disease is a rare nonatheromatous cause of popliteal artery disease. Here, we present a case of a 51-year-old male patient who presented with right calf claudication caused by adventitial cystic disease. Preoperative magnetic resonance imaging and intraoperative findings revealed the presence of a connection between the cyst and adjacent knee joint. In addition, histopathological examination revealed that the tissue structure of the connection was similar to that of adventitial cysts. The tissue composed of 2 types of cells, namely macrophages and fibroblast-like cells, and lesional cells expressed D2-40. These findings supported the ganglion theory as the underlying physiopathology of this disease and were helpful in deciding the management of this case.

The effects of two-stage carotid occlusion on spatial memory and pro-inflammatory markers in the hippocampus of rats

The purpose of this study was to evaluate the effects of cerebral hypoperfusion on cognitive ability, TNFα, IL1β and PGE2 levels in both hippocampi in a modified two-vessel occlusion model. Both common carotid arteries of adult male Wistar rats were permanently occluded with an interval of 1 week between occlusions. Learning and memory were significantly decreased after 1 month. This reduction was not significant after 2 months, which may be attributed to blood flow compensation. The TNFα level was significantly increased after 3 h and 1 day. IL1β was significantly increased after 1 day. After a week there was no significant difference in pro-inflammatory levels. Furthermore, there was no difference between right and left hippocampi. It is possible that TNFα and IL1β elevation initiates pathologic processes that contribute to memory impairment.

Swirling of microbubbles: Demonstration of a new finding of carotid plaque ulceration on contrast-enhanced ultrasound explaining the arterio-arterial embolism mechanism

Carotid plaque ulceration is a well-established feature of vulnerability, associated with high risk for neurological symptoms. From a pathogenetic point of view, the mechanism responsible for occurrence of symptomatology relies on the aggregation of platelets within the ulcer cavity, activation of coagulation mechanism, formation of thrombus and arterio-arterial embolization of thrombotic material in the central nervous system. Many imaging modalities including unenhanced ultrasound, computed tomographic angiography and magnetic resonance angiography have been used to image and diagnose carotid plaque ulceration with varying success. Contrast-enhanced ultrasound has been recently introduced in the study of carotid disease offering improved flow visualization and better plaque surface delineation. We present a case where contrast-enhanced ultrasound visualized the swirling pattern of movement of the microbubbles within the ulcer cavity. These findings illustrate the underlying hemodynamic mechanism of arterio-arterial embolization and can be proposed as a new finding of plaque ulcerations on contrast-enhanced ultrasound.

Anesthesia-Induced Hypothermia Attenuates Early-Phase Blood-Brain Barrier Disruption but Not Infarct Volume following Cerebral Ischemia

Blood-brain barrier (BBB) disruption is thought to facilitate the development of cerebral infarction after a stroke. In a typical stroke model (such as the one used in this study), the early phase of BBB disruption reaches a peak 6 h post-ischemia and largely recovers after 8–24 h, whereas the late phase of BBB disruption begins 48–58 h post-ischemia. Because cerebral infarct develops within 24 h after the onset of ischemia, and several therapeutic agents have been shown to reduce the infarct volume when administered at 6 h post-ischemia, we hypothesized that attenuating BBB disruption at its peak (6 h post-ischemia) can also decrease the infarct volume measured at 24 h. We used a mouse stroke model obtained by combining 120 min of distal middle cerebral arterial occlusion (dMCAo) with ipsilateral common carotid arterial occlusion (CCAo). This model produced the most reliable BBB disruption and cerebral infarction compared to other models characterized by a shorter duration of ischemia or obtained with dMCAO or CCAo alone. The BBB permeability was measured by quantifying Evans blue dye (EBD) extravasation, as this tracer has been shown to be more sensitive for the detection of early-phase BBB disruption compared to other intravascular tracers that are more appropriate for detecting late-phase BBB disruption. We showed that a 1 h-long treatment with isoflurane-anesthesia induced marked hypothermia and attenuated the peak of BBB disruption when administered 6 h after the onset of dMCAo/CCAo-induced ischemia. We also demonstrated that the inhibitory effect of isoflurane was hypothermia-dependent because the same treatment had no effect on ischemic BBB disruption when the mouse body temperature was maintained at 37°C. Importantly, inhibiting the peak of BBB disruption by hypothermia had no effect on the volume of brain infarct 24 h post-ischemia. In conclusion, inhibiting the peak of BBB disruption is not an effective neuroprotective strategy, especially in comparison to the inhibitors of the neuronal death signaling cascade; these, in fact, can attenuate the infarct volume measured at 24 h post-ischemia when administered at 6 h in our same stroke model.

Computational evaluation of smoothed particle hydrodynamics for implementing blood flow modelling through CT reconstructed arteries

Simulation of blood flow in a stenosed artery using Smoothed Particle Hydrodynamics (SPH) is a new research field, which is a particle-based method and different from the traditional continuum modelling technique such as Computational Fluid Dynamics (CFD). Both techniques harness parallel computing to process hemodynamics of cardiovascular structures. The objective of this study is to develop and test a new robust method for comparison of arterial flow velocity contours by SPH with the well-established CFD technique, and the implementation of SPH in computed tomography (CT) reconstructed arteries. The new method was developed based on three-dimensional (3D) straight and curved arterial models of millimeter range with a 25% stenosis in the middle section. In this study, we employed 1,000 to 13,000 particles to study how the number of particles influences SPH versus CFD deviation for blood-flow velocity distribution. Because further increasing the particle density has a diminishing effect on this deviation, we have determined a critical particle density of 1.45 particles/mm2 based on Reynolds number (Re = 200) at the inlet for an arterial flow simulation. Using this critical value of particle density can avoid unnecessarily big computational expenses that have no further effect on simulation accuracy. We have particularly shown that the SPH method has a big potential to be used in the virtual surgery system, such as to simulate the interaction between blood flow and the CT reconstructed vessels, especially those with stenosis or plaque when encountering vasculopathy, and for employing the simulation results output in clinical surgical procedures.

[Use of a filtering protective device during angioplasty and stenting of the brachiocephalic trunk]

The authors carried out a pilot study aimed at assessing the possibility and efficacy of using filtering systems for protection of cerebral arteries from distal embolism during angioplasty and stenting of the brachiocephalic trunk. A total of five patients presenting with lesions of the brachiocephalic trunk underwent 5 roentgenoendovascular interventions with the use of the filtering protective device Spider FX. Angiographic and clinical success was achieved in 100% of cases. Particles of debris were obtained from the protective device in all cases. All the five patients were found to have symptoms of vertebrobasilar insufficiency. During follow-up in the medium-term period at check examinations the implanted stents were patent, with neither major nor minor neurological complications observed. The patients turned out to be free from cerebrovascular insufficiency relapses. Presented herein are clinical case reports describing technical peculiarities of using the protective device in different variants of the anatomy and vascular lesion.

Interventional Techniques to Facilitate Supraaortic Angioplasty and Stenting

Arterial occlusive disease involving the supra-aortic trunks (SATs) is relatively frequent. Its mere presence does not dictate the need for intervention. Revascularization options include intra and extrathoracic surgical bypasses and transpositions, and percutaneous endovascular approaches with angioplasty and stenting. This paper focuses on a description of the fundamental endovascular techniques and equipment that have proved useful in the senior author's (FJC) 15-year experience with catheter-based intervention for treatment of SAT disease. These procedures have gained in popularity over the years and become the preferred modality for management of most patients today.

Suppression of ischemia in arterial occlusive disease by JNK-promoted native collateral artery development

Arterial occlusive diseases are major causes of morbidity and mortality. Blood flow to the affected tissue must be restored quickly if viability and function are to be preserved. We report that disruption of the mixed-lineage protein kinase (MLK) - cJun NH2-terminal kinase (JNK) signaling pathway in endothelial cells causes severe blockade of blood flow and failure to recover in the murine femoral artery ligation model of hindlimb ischemia. We show that the MLK-JNK pathway is required for the formation of native collateral arteries that can restore circulation following arterial occlusion. Disruption of the MLK-JNK pathway causes decreased Dll4/Notch signaling, excessive sprouting angiogenesis, and defects in developmental vascular morphogenesis. Our analysis demonstrates that the MLK-JNK signaling pathway is a key regulatory mechanism that protects against ischemia in arterial occlusive disease.

Arterial endofibrosis in professional cyclists

External Iliac Artery Endofibrosis (EIAE) is an uncommon disease usually affecting young, otherwise healthy, patients. It usually involves cyclists but cases have been reported in other groups of endurance athletes. The external iliac artery is the most affected anatomical site but other locations are described too. The precise pathophysiology and long-term evolution of the disease still remain unknown. The diagnosis may be challenging and delayed as the patients usually present symptoms only in extreme conditions and physical and instrumental examinations may be normal at rest. We present two cases of young professional cyclists who suffered of exercise-induced leg pain which led them to reduce running. Both patients were firstly treated with balloon angioplasty that rapidly failed to improve their symptoms. The successive open surgery with endofibrosectomy and autologous saphenous vein closure patch completely resolved physical limitations. EIAE is a rare disease that can induce arterial stenosis, thrombosis, dissection and secondary atheroma. After-exercise ankle-brachial index represents a useful diagnostic criterion. Careful observation of angio-CT may strengthen the suspect. Knowledge of the these features allows a better pre-operative assessment and an early effective treatment. Surgical revascularization remains the gold standard approach.

Two-Year Results after Directional Atherectomy of Infrapopliteal Arteries with the SilverHawk Device

Purpose:

To report the 12- and 24-month results after directional atherectomy (DA) of below-the-knee (BTK) arterial lesions with the SilverHawk device.

Methods:

Forty-nine BTK lesions in 36 patients (58% men; mean age 70611 years) with peripheral occlusive disease of the lower limbs were treated with DA; 19 (53%) of the limbs were classified with Rutherford-Becker 4 or 5 ischemia. Target lesions were in the popliteal artery (n=6, 12%), tibioperoneal trunk (n=25, 51%), peroneal artery (n=10, 20%), anterior tibial artery (n=5, 10%), and posterior tibial artery (n=3, 6%). Nine (18%) lesions were located in a stent. Twelve lesions extended to 2 artery segments. The average degree of diameter stenosis was 89%±10% (range 70%–100%); there were 11 (22%) occlusions. The mean lesion length was 48±28 mm.

Results:

Sixteen (33%) lesions were treated after predilation; 33 (67%) lesions were treated with primary DA. All but 1 (2%) lesion could be treated with DA. In 19 (39%) lesions, additional balloon angioplasty was performed, and 2 (4%) lesions required stent implantation as a result of dissection. The mean stenosis diameter after DA was 12%±18% (range 0%–100%). After additional therapy, the mean stenosis diameter was 8%±9% (range 0%–100%). A residual stenosis ≤30% was achieved in 48 (98%) lesions. The mean ankle-brachial index significantly increased from 0.48±0.26 to 0.81±0.32 (p<0.05) before discharge and remained improved during follow-up. Primary and secondary patency rates were 67% and 91% after 1 year and 60% and 80% after 24 months. The 12-and 24-month cumulative event-free survival rates (primary patency) by Kaplan-Meier analysis were 58%±8% and 46%±9%; at the same time intervals, the cumulative survival rates (secondary patency) were 88%±6% and 73%±9%, respectively.

Conclusion:

BTK lesions can be treated successfully and safely with DA. Midterm clinical results are encouraging.

Contemporary Endovascular Treatment for Disease of the Superficial Femoral and Popliteal Arteries: An Integrated Device-Based Strategy

Endovascular therapy for disease of the superficial femoral artery (SFA) and the popliteal artery remains controversial. Percutaneous treatment of this arterial segment presents a particular technical challenge, as the extent of disease varies from short, focal, and stenotic to long, diffuse, and occluded lesions. Over the last 2 decades, multiple therapies have been evaluated, including simple balloon angioplasty, directional atherectomy, stenting (both balloon-expandable and self-expanding), and more recently, intra-arterial radiation, laser, and cryotherapy. Regardless of which modality is used, however, endovascular therapy as a revascularization strategy has the potential to improve symptoms and quality of life and, in selected patients, to avoid limb amputation. While percutaneous endovascular treatment has been historically associated with high procedural success and favorable short and intermediate-term patency rates, long-term clinical results have proven disappointing. Conventional balloon angioplasty is limited by elastic recoil, dissection, and restenosis. Balloon-expandable stents (particularly in the distal SFA) are associated with late stent deformation and mechanical compression, with resultant late clinical failure. Newer self-expanding stents have shown improved initial results but have been limited by late mechanical fatigue and associated restenosis. With the development of several newer endovascular techniques in recent years, the possibilities for treating this condition have increased dramatically. Currently, no long-term comparative data exist regarding the role of these alternative technologies. This article summarizes and compares important data about new endovascular options for intervention therapy in SFA and popliteal disease. In addition, based on this analysis, we propose a contemporary treatment strategy, integrating older and newer technologies into a real-world algorithm.

Angiographic Structural Differentiation between Native Arteriogenesis and Therapeutic Synangiosis in Intracranial Arterial Steno-Occlusive Disease

BACKGROUND AND PURPOSE

Encephaloduroarteriosynangiosis has been shown to generate collateral vessels from the extracranial-to-intracranial circulation in patients with Moyamoya disease and intracranial arterial steno-occlusive disease. The mechanisms involved are not well-understood. We hypothesized that angiogenesis is the leading mechanism forming collaterals after encephaloduroarteriosynangiosis because there are no pre-existing connections. Angiogenesis-generated collaterals should exhibit higher architectural complexity compared with innate collaterals.

MATERIALS AND METHODS

Pre- and postoperative digital subtraction angiograms were analyzed in patients enrolled in a prospective trial of encephaloduroarteriosynangiosis surgery. Branching angioscore, tortuosity index, and local connected fractal dimension were compared between innate and postoperative collaterals.

RESULTS

One hundred one angiograms (50 preoperative, 51 postoperative) were analyzed from 44 patients (22 with intracranial atherosclerosis and 22 with Moyamoya disease). There was a significantly higher median branching angioscore (13 versus 4, P < .001) and a lower median tortuosity index (1.08 versus 1.76, P < .001) in the encephaloduroarteriosynangiosis collaterals compared with innate collaterals. Higher mean local fractal dimension peaks (1.28 ± 0.1 versus 1.16 ± 0.11, P < .001) were observed in the encephaloduroarteriosynangiosis collaterals compared with innate collaterals for both intracranial atherosclerosis (P < .001) and Moyamoya disease (P < .001) groups. The observed increase in high connectivity was greater in the intracranial atherosclerosis group compared with patients with Moyamoya disease (P = .01).

CONCLUSIONS

The higher median branching angioscore and local connected fractal dimension, along with the lower median tortuosity index of encephaloduroarteriosynangiosis collaterals, are consistent with the greater complexity observed in the process of sprouting and splitting associated with angiogenesis.

Aortic Intimal Sarcoma Contributes to Atherosclerotic Renovascular Hypertension: An Autopsy Case Report and Review of the Literature

An autopsy of a 70-year-old man with multiple bone metastases from a malignancy of unknown origin (MUO) and renovascular hypertension revealed an aortic intimal sarcoma (AIS) in the right renal artery accompanied by atherosclerotic changes. AIS appeared as aggregated mutton fat-like translucent particles arising from the intima of the branching portion of the right renal artery and was composed of undifferentiated, fine spindle cells with thicket-like proliferation. AIS was confirmed by immunohistopathology, showing the loss of the lumen lined by CD31-positive endothelium and the expression of CD31, keratin, and vimentin in the viable part of the tumor. In patients with MUO presenting with both bone metastases and an acute or sub-acute onset of renovascular hypertension, AIS in the renal artery may be responsible.

Dixon-based fat-free MR-angiography compared to first pass and steady-state high-resolution MR-angiography using a blood pool contrast agent

INTRODUCTION

Compared to standard arterial-only first-pass MR-angiography (FPMRA), imaging during the equilibrium phase of a blood pool contrast agent (steady state) has been shown to provide higher image quality and better stenosis grading. Homogenous Dixon fat-suppression promises to increase contrast by suppression of fat adjacent to vessels. This study was performed to compare diagnostic image quality and vessel-to-background contrasts in equilibrium phase Dixon-based fat-free MRA (DFSMRA) of run-off vessels to FPMRA imaging and equilibrium phase T1-weighted non-fat-suppressed ultra-high resolution MRA (SSMRA).

MATERIAL AND METHODS

In a prospective, intra-individual comparative study, 17 patients with known or suspected peripheral arterial occlusive disease (PAOD; 11 men, mean age 65.6±18.1 [23-89] years) received FPMRA, DFSMRA, and SSMRA at 1.5 Tesla using a clinical whole body MRI scanner. All sequences were performed within the same session applying a single dose of a blood pool contrast agent (gadofosveset trisodium) that was injected during acquisition of FPMRA. The diagnostic image quality of the run-off vessels was evaluated on a 3-point scale. Quantitative analysis consisted of contrast-ratio (CR) measurements of vascular lumen signals compared to signals of adjacent muscle and fat.

RESULTS

The average image quality of vessel visualization was rated highest in SSMRA (mean 1.34±0.41), followed by standard FPMRA (mean 1.15±0.33) and DFSMRA (mean 0.99±0.61). Image quality was rated similarly high in the thighs and pelvic region, whereas small vessels in the lower legs and in the feet were best visualized by SSMRA. CR of vascular lumen compared to adjacent fatty tissue was 2.7 times higher in DFSMRA compared to SSMRA, whereas CR of vascular lumen to muscle was 1.3 times higher in SSMRA.

CONCLUSION

Vessel to fat contrast is strongly increased in DFSMRA compared to T1-weighted ultra-high resolution non-fat suppressed SSMRA, whereas vessel to muscle contrast is decreased in DFSMRA. Given the current technical limitations of DFSMRA, possible benefits are outweighed by advantages of first-pass imaging regarding arterial selectivity as well as advantages of SSMRA with respect to spatial resolution.

Obstructions in Vascular Networks: Relation Between Network Morphology and Blood Supply

We relate vascular network structure to hemodynamics after vessel obstructions. We consider tree-like networks with a viscoelastic fluid with the rheological characteristics of blood. We analyze the network hemodynamic response, which is a function of the frequencies involved in the driving, and a measurement of the resistance to flow. This response function allows the study of the hemodynamics of the system, without the knowledge of a particular pressure gradient. We find analytical expressions for the network response, which explicitly show the roles played by the network structure, the degree of obstruction, and the geometrical place in which obstructions occur. Notably, we find that the sequence of resistances of the network without occlusions strongly determines the tendencies that the response function has with the anatomical place where obstructions are located. We identify anatomical sites in a network that are critical for its overall capacity to supply blood to a tissue after obstructions. We demonstrate that relatively small obstructions in such critical sites are able to cause a much larger decrease on flow than larger obstructions placed in non-critical sites. Our results indicate that, to a large extent, the response of the network is determined locally. That is, it depends on the structure that the vasculature has around the place where occlusions are found. This result is manifest in a network that follows Murray’s law, which is in reasonable agreement with several mammalian vasculatures. For this one, occlusions in early generation vessels have a radically different effect than occlusions in late generation vessels occluding the same percentage of area available to flow. This locality implies that whenever there is a tissue irrigated by a tree-like in vivo vasculature, our model is able to interpret how important obstructions are for the irrigation of such tissue.

Potential contribution of phenotypically modulated smooth muscle cells and related inflammation in the development of experimental obstructive pulmonary vasculopathy in rats

We tested the hypothesis that phenotypically modulated smooth muscle cells (SMCs) and related inflammation are associated with the progression of experimental occlusive pulmonary vascular disease (PVD). Occlusive PVD was induced by combined exposure to a vascular endothelial growth factor receptor tyrosine kinase inhibitor Sugen 5416 and hypobaric hypoxia for 3 weeks in rats, which were then returned to ambient air. Hemodynamic, morphometric, and immunohistochemical studies, as well as gene expression analyses, were performed at 3, 5, 8, and 13 weeks after the initial treatment (n = 78). Experimental animals developed pulmonary hypertension and right ventricular hypertrophy, and exhibited a progressive increase in indices of PVD, including cellular intimal thickening and intimal fibrosis. Cellular intimal lesions comprised α smooth muscle actin (α SMA)+, SM1+, SM2+/-, vimentin+ immature SMCs that were covered by endothelial monolayers, while fibrous intimal lesions typically included α SMA+, SM1+, SM2+, vimentin+/- mature SMCs. Plexiform lesions comprised α SMA+, vimentin+, SM1-, SM2- myofibroblasts covered by endothelial monolayers. Immature SMC-rich intimal and plexiform lesions were proliferative and were infiltrated by macrophages, while fibrous intimal lesions were characterized by lower proliferative abilities and were infiltrated by few macrophages. Compared with controls, the number of perivascular macrophages was already higher at 3 weeks and progressively increased during the experimental period; gene expression of pulmonary hypertension-related inflammatory molecules, including IL6, MCP1, MMP9, cathepsin-S, and RANTES, was persistently or progressively up-regulated in lungs of experimental animals. We concluded that phenotypically modulated SMCs and related inflammation are potentially associated with the progression of experimental obstructive PVD.

[Efficacy of balloon catheters with antiproliferative cover in patients with impairment of arteries of femoral-popliteal segment]

Results of treatment of 30 patients, suffering affection of arteries of femoro-popliteal segment, using balloon catheters with treating cover, are analyzed. There was proved, that balloon angioplasty, comparing with routine angioplasty, provide for significantly better the indices of primary passability of operated arteries, as well as reduce the rate of restenosis occurrence in late period.

Site-specific association between distal aortic pulse wave velocity and peripheral arterial stenosis severity: a prospective cardiovascular magnetic resonance study

BACKGROUND

Vascular disease expression in one location may not be representative for disease severity in other vascular territories, however, strong correlation between disease expression and severity within the same vascular segment may be expected. Therefore, we hypothesized that aortic stiffening is more strongly associated with disease expression in a vascular territory directly linked to that aortic segment rather than in a more remote segment. We prospectively compared the association between aortic wall stiffness, expressed by pulse wave velocity (PWV), sampled in the distal aorta, with the severity of peripheral arterial occlusive disease (PAOD) as compared to atherosclerotic markers sampled in remote vascular territories such as PWV in the proximal aorta and the normalized wall index (NWI), representing the vessel wall thickness, of the left common carotid artery.

METHODS

Forty-two patients (23 men; mean age 64±10 years) underwent velocity-encoded cardiovascular magnetic resonance (CMR) in the proximal and distal aorta, whole-body contrast-enhanced MR angiography (CE-MRA) and carotid vessel wall imaging with black-blood CMR in the work-up for PAOD. Strength of associations between aortic stiffness, carotid NWI and peripheral vascular stenosis grade were assessed and evaluated with multiple linear regression.

RESULTS

Stenosis severity correlated well with PWV in the distal aorta (Pearson rP=0.64, p<0.001, Spearman rS=0.65, p<0.001) but to a lesser extent with PWV in the proximal aorta (rP=0.48, p=0.002, rS=0.22, p=0.18). Carotid NWI was not associated with peripheral stenosis severity (rP=0.17, p=0.28, rS=0.14, p=0.37) nor with PWV in the proximal aorta (rP=0.22, p=0.17) nor in the distal aorta (rP=0.21, p=0.18). Correlation between stenosis severity and distal aortic PWV remained statistically significant after correction for age and gender.

CONCLUSIONS

Distal aortic wall stiffness is more directly related to peripheral arterial stenosis severity than markers from more remote vascular territories such as proximal aortic wall stiffness or carotid arterial wall thickness. Site-specific evaluation of vascular disease may be required for full vascular risk estimation.

Deformity of subclavian artery as a cause of formation of vertebral subclavian steal syndrome

Presented herein are 3 clinical case reports concerning formation of vertebral subclavian steal syndrome in deformities of subclavian arteries. By means of duplex scanning, angiography and multispiral computed tomography it was shown that deformities of subclavian arteries in the first segment (proximal to the origin of the vertebral artery) with septal stenosing are accompanied by a typical dopplerographic picture_pattern of steal syndrome.

Below-knee arterial calcification in type 2 diabetes: association with receptor activator of nuclear factor κB ligand, osteoprotegerin, and neuropathy

CONTEXT

Calcification of the arterial wall in diabetes contributes to the arterial occlusive process occurring below the knee. The osteoprotegerin (OPG)/receptor activator of nuclear factor κB ligand (RANKL) system is suspected to be involved in the calcification process.

OBJECTIVE

The aim of the study was to investigate whether there is a link between arterial calcification in type 2 diabetes and 1) conventional cardiovascular risk factors, 2) serum RANKL and OPG levels, and 3) neuropathy.

PATIENTS AND METHODS

We objectively scored, in a cross-sectional study, infrapopliteal vascular calcification using computed tomography scanning in 198 patients with type 2 diabetes, a high cardiovascular risk, and a glomerular filtration rate >30 mL/min. Color duplex ultrasonography was performed to assess peripheral arterial occlusive disease, and mediacalcosis. Peripheral neuropathy was defined by a neuropathy disability score >6. RANKL and OPG were measured in the serum by routine chemistry.

RESULTS

Below-knee arterial calcification was associated with arterial occlusive disease. In multivariate logistic regression analysis, the variables significantly and independently associated with the calcification score were age (odds ratio [OR] = 1.08; 95% confidence interval [CI] = 1.04-1.13; P < .0001), male gender (OR = 3.53; 95% CI = 1.54-8.08; P = .003), previous cardiovascular disease (OR = 2.78; 95% CI = 1.39-5.59; P = .005), and neuropathy disability score (per 1 point, OR = 1.21; 95% CI = 1.05-1.38; P = .006). The association with ln OPG, significantly associated with calcification score in univariate analysis (OR = 3.14; 95% CI = 1.05-9.40; P = .045), was no longer significant in multivariate analysis. RANKL and OPG/RANKL were not significantly associated with the calcification score.

CONCLUSIONS

Below-knee arterial calcification severity is clearly correlated with peripheral neuropathy severity and with several usual cardiovascular risk factors, but not with serum RANKL level.

Pre-uremic calciphylaxis

Calciphylaxis is characterized by calcification and thrombosis of arteries resulting in ischemic necrosis of predominantly skin and subcutaneous tissue. Primarily affecting patients with end-stage renal disease, calciphylaxis is diagnosed rarely in the absence of renal replacement therapy. We report an elderly obese woman presented with leg pain and ulceration. She had chronic kidney disease, diabetes mellitus, hypertension, and peripheral vascular disease. Angiography revealed occlusion of the left superficial femoral, popliteal, and distal tibial arteries. Amputation was performed. Histological examination demonstrated medial calcification, intimal hyperplasia, and thrombosis of small- and medium-sized arteries in the subcutaneous tissue. This case features calciphylaxis in a patient with chronic kidney disease before the onset of uremia. Calciphylaxis and atherosclerotic peripheral vascular disease have several risk factors in common. This report calls attention to a disorder that can be masqueraded as leg ulceration due to peripheral vascular disease in the absence of renal replacement therapy.

Use of optical coherence tomography during superficial femoral artery interventions

Superficial femoral artery (SFA) disease accounts for approximately 40% of the symptomatic peripheral arterial disease and remains a common cause of critical limb ischemia and lower-extremity amputation. Optical coherence tomography (OCT) has been extensively studied in the coronary circulation; however, its use in the peripheral arterial circulation is scarce. We present two cases of OCT use as an ancillary imaging tool during SFA endovascular interventions.

Non-contrast-enhanced MR angiography at 3 Tesla in patients with advanced peripheral arterial occlusive disease

Purpose

The aim of this study was to assess the diagnostic performance of ECG-gated non-contrast-enhanced quiescent interval single-shot (QISS) magnetic resonance angiography at a magnetic field strength of 3 Tesla in patients with advanced peripheral arterial occlusive disease (PAOD).

Method and Materials

A total of 21 consecutive patients with advanced PAOD (Fontaine stage IIb and higher) referred for peripheral magnetic resonance angiography (MRA) were included. Imaging was performed on a 3 T whole body MR. Image quality and stenosis diameter were evaluated in comparison to contrast-enhanced continuous table and TWIST MRA (CE-MRA) as standard of reference. QISS images were acquired with a thickness of 1.5 mm each (high-resolution QISS, HR-QISS). Two blinded readers rated the image quality and the degree of stenosis for both HR-QISS and CE-MRA in 26 predefined arterial vessel segments on 5-point Likert scales.

Results

With CE-MRA as the reference standard, HR-QISS showed high sensitivity (94.1%), specificity (97.8%), positive (95.1%), and negative predictive value (97.2%) for the detection of significant (≥50%) stenosis. Interreader agreement for stenosis assessment of both HR-QISS and CE-MRA was excellent (κ-values of 0.951 and 0.962, respectively). As compared to CR-MRA, image quality of HR-QISS was significantly lower for the distal aorta, the femoral and iliac arteries (each with p<0.01), while no significant difference was found in the popliteal (p = 0.09) and lower leg arteries (p = 0.78).

Conclusion

Non-enhanced ECG-gated HR-QISS performs very well in subjects with severe PAOD and is a good alternative for patients with a high risk of nephrogenic systemic fibrosis.

In vivo feasibility study of ultrasound potentiated collagenase therapy of chronic total occlusions

Arterial chronic total occlusions (CTOs) pose considerable challenges for percutaneous interventions, due primarily to the presence of stiff proximal fibrous caps (PFCs) which act as a barrier to the penetration of guide wires. A new approach under development for improving the success rate of guide wire crossing in CTOs is to employ collagenase to degrade the mechanical integrity of the PFCs. This has been shown to be feasible in preclinical work and in a Phase 1 clinical trial. In a recent study we demonstrated using ex vivo experimental CTO specimens that ultrasound-stimulated microbubbles (USMBs) could potentiate the effects of collagenase and result in increased mechanical degradation of the PFCs of CTOs. Here we report the results of the first in vivo study examining the feasibility of this approach, which demonstrates that the force required to puncture through the PFCs of CTOs is reduced with combined USMB+collagenase treatments relative to collagenase only treatments. This approach has the potential to further improve the efficacy of the emerging technique of collagenase facilitation of percutaneous interventions for CTO.

Detection of infragenual arterial disease using non-contrast-enhanced MR angiography in patients with diabetes

PURPOSE

To evaluate the diagnostic performance of a newly developed non-contrast-enhanced MR angiography (NCE-MRA) technique using flow-sensitive dephasing (FSD) prepared steady-state free precession (SSFP) for detecting calf arterial disease in patients with diabetes.

MATERIALS AND METHODS

Forty-five patients with diabetes who underwent routine contrast-enhanced MR angiography (CE-MRA) of lower extremities were recruited for NCE-MRA at the calf on a 1.5 Tesla MR system. Image quality evaluated on a 4-point scale and diagnostic performance for detecting more than 50% arterial stenosis were statistically analyzed, using CE-MRA as the standard of reference.

RESULTS

A total of 264 calf arterial segments were obtained in the 45 patients with 88 legs. The percentage of diagnostic arterial segments was all 98% for NCE- and CE-MRA. The image quality, SNR, CNR was 3.3, 177, 138, and 3.5, 103, 99, for NCE-MRA and CE-MRA, respectively. The average sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NCE-MRA were 97%, 96%, 90%, 99%, and 96%, respectively on a per-segment basis and 90%, 84%, 82%, 91%, and 87%, respectively, on a per-patients basis.

CONCLUSION

The NCE-MRA technique demonstrates adequate image quality in the delineation of calf arteries and consistent diagnostic performance for detecting significant stenosis with CE-MRA in patients with diabetes.