[Influence of oversizing of endovascular stent-graft to prognosis of aortic dissection]

With the increasing application of endovascular stent-graft in the treatment of aortic dissection, there are still some problems and controversies in the selection of the stent-graft oversizing. This review summarized the latest research in the study of the baseline and measurement in stent-graft oversizing selection, the relationship between stent-graft oversizing and prognosis and the selection of stent-graft oversizing in different patients with different conditions, providing a reference for the endovascular stent-graft oversizing selection in the treatment of aortic dissection.

[Attach importance to the planning and implementation of endovascular repair for ascending aorta dissection]

Since 2000 Dorros et al. reported the first case of type A aortic dissection (TAAD) treated with an endovascular repair, surgeons explored a novel treatment option for TAAD gradually. The application of endovascular repair for TAAD highlights some points below which should pay attention to because of the special anatomic location and morphological characteristics of ascending aorta: (1) customized treatment strategy based on the characteristics of patients; (2) pre-operation evaluation; (3) selection of the stent and delivery system; (4) selection of the access sites; (5) preservation of the coronary artery flow, aortic valve function and perfusion of the branch vessels; (6) accurate location of stent-graft; (7) mid-term and long-term follow-up. In a word, it's helpful to avoid misunderstanding in treatment and improve the safety of operation by grasping the indication and the technical points and making the customized treatment strategy based on the characteristics of patients.

A uni-extension study on the ultimate material strength and extreme extensibility of atherosclerotic tissue in human carotid plaques

Atherosclerotic plaque rupture occurs when mechanical loading exceeds its material strength. Mechanical analysis has been shown to be complementary to the morphology and composition for assessing vulnerability. However, strength and stretch thresholds for mechanics-based assessment are currently lacking. This study aims to quantify the ultimate material strength and extreme extensibility of atherosclerotic components from human carotid plaques. Tissue strips of fibrous cap, media, lipid core and intraplaque hemorrhage/thrombus were obtained from 21 carotid endarterectomy samples of symptomatic patients. Uni-extension test with tissue strips was performed until they broke or slid. The Cauchy stress and stretch ratio at the peak loading of strips broken about 2 mm away from the clamp were used to characterize their ultimate strength and extensibility. Results obtained indicated that ultimate strength of fibrous cap and media were 158.3 [72.1, 259.3] kPa (Median [Inter quartile range]) and 247.6 [169.0, 419.9] kPa, respectively; those of lipid and intraplaque hemorrhage/thrombus were 68.8 [48.5, 86.6] kPa and 83.0 [52.1, 124.9] kPa, respectively. The extensibility of each tissue type were: fibrous cap – 1.18 [1.10, 1.27]; media – 1.21 [1.17, 1.32]; lipid – 1.25 [1.11, 1.30] and intraplaque hemorrhage/thrombus – 1.20 [1.17, 1.44]. Overall, the strength of fibrous cap and media were comparable and so were lipid and intraplaque hemorrhage/thrombus. Both fibrous cap and media were significantly stronger than either lipid or intraplaque hemorrhage/thrombus. All atherosclerotic components had similar extensibility. Moreover, fibrous cap strength in the proximal region (closer to the heart) was lower than that of the distal. These results are helpful in understanding the material behavior of atherosclerotic plaques.

Prognostic Impact of Blood Pressure Variability on Aortic Dissection Patients After Endovascular Therapy

Hypertension has been deemed as a pivotal risk factor for the development of aortic dissection; however, the importance and prognostic significance of blood pressure variability (BPV) in aortic dissection are always ignored. A total of 173 acute type B aortic dissection patients were enrolled in and retrospectively reviewed between January 2009 and November 2013. There were 74 patients with high BPV and 99 with low BPV stratified by preoperative mean BPV. Technical success was achieved in all patients. The proportions of hypertension and general anesthesia were significantly higher in the high BPV group (70.3% vs 55.6% and 77% vs 62.6%, P = 0.049 and 0.043, respectively). The risk of aorta-related death in the high BPV group was apparently higher than the low BPV group (28.4% vs 9.1%, P = 0.001). By performing multivariable logistic regression, we found history of hypertension was likely to be a risk factor of BPV (95% confidence interval [CI]: 1.010-3.911), and high BPV was an independent predictor of aorta-related death (95% CI: 1.671-9.587). The difference of aorta-related mortality was pronounced between high and low BPV subgroups regardless of the refractory hypertension (41.4% vs 14.3% and 20.0% vs 7.0%, P = 0.023 and 0.037, respectively). The thrombosis ratio of false lumen was significantly higher in the low BPV group at 3-month (72.4 ± 17.5% vs 51.8 ± 11.6%, P < 0.001) and 6-month (86.4 ± 9.1% vs 69.7 ± 7.9%, P < 0.001). High BPV is an independent risk factor for the prognosis of aortic dissection. Further studies on BPV might provide new preventive and therapeutic strategies for aortic dissection.

Influence of material property variability on the mechanical behaviour of carotid atherosclerotic plaques: a 3D fluid-structure interaction analysis

Mechanical analysis has been shown to be complementary to luminal stenosis in assessing atherosclerotic plaque vulnerability. However, patient-specific material properties are not available and the effect of material properties variability has not been fully quantified. Media and fibrous cap (FC) strips from carotid endarterectomy samples were classified into hard, intermediate and soft according to their incremental Young's modulus. Lipid and intraplaque haemorrhage/thrombus strips were classified as hard and soft. Idealised geometry-based 3D fluid-structure interaction analyses were performed to assess the impact of material property variability in predicting maximum principal stress (Stress-P1 ) and stretch (Stretch-P1 ). When FC was thick (1000 or 600 µm), Stress-P1 at the shoulder was insensitive to changes in material stiffness, whereas Stress-P1 at mid FC changed significantly. When FC was thin (200 or 65 µm), high stress concentrations shifted from the shoulder region to mid FC, and Stress-P1 became increasingly sensitive to changes in material properties, in particular at mid FC. Regardless of FC thickness, Stretch-P1 at these locations was sensitive to changes in material properties. Variability in tissue material properties influences both the location and overall stress/stretch value. This variability needs to be accounted for when interpreting the results of mechanical modelling.

Systematic Review and Meta-Analysis of Carotid Artery Stenting Versus Endarterectomy for Carotid Stenosis: A Chronological and Worldwide Study

There are disparities among the results of meta-analyses under different circumstances of carotid artery stenting (CAS) versus endarterectomy (CEA) for carotid stenosis. This study aimed to assess the efficacies of CAS and CEA for carotid stenosis at 5-year intervals and worldwide.Comparative studies simultaneously reporting CAS and CEA for carotid stenosis with at least 10 patients in each group were identified by searching PubMed and Embase in accordance with preferred reporting items for systematic reviews and meta-analyses guidelines, and by reviewing the reference lists of retrieved articles.The studies were stratified into different subgroups according to the publication year, location in which the study was mainly performed, and randomized and nonrandomized study designs.Thirty-five comparative studies encompassing 27,525 patients were identified. The risk ratios (RRs) of stroke/death when CAS was compared with CEA within 30 d of treatment were 1.51 (95% CI 1.32-1.74, P < 0.001) for overall, 1.50 (95% CI 1.14-1.98, P = 0.004) from 2011 to 2015, 1.61 (95% CI 1.35-1.91, P < 0.001) from 2006 to 2010, 1.59 (95% CI 1.27-1.99, P < 0.001) in North America, 1.50 (95% CI 1.24-1.81, P < 0.001) in Europe, 1.63 (95% CI 1.31-2.02, P < 0.001) for randomized, and 1.44 (95% CI 1.20-1.73, P < 0.001) for nonrandomized comparative studies. CEA decreased the risks of transient ischemic attack at 30 d (RR: 2.07, 95% CI 1.50-2.85, P < 0.001) and restenosis at 1-year (RR: 1.97, 95% CI 1.28-3.05, P = 0.002). Data from follow-up showed that the RRs of stroke/death were 0.74 (95% CI 0.55-0.99, P = 0.04) at 1 year, 1.24 (95% CI 1.04-1.46, P = 0.01) at 4 year, and 2.27 (95% CI 1.39-3.71, P = 0.001) at 10 year. This systematic review, compared with those of other meta-analyses, included all available comparative studies and analyzed them at 5-year intervals, in different continents, and under different study designs. Current evidence suggests that the efficacy of CEA is superior to CAS for freedom from stroke/death within 30 d, especially from 2006 to 2015, in North America and Europe. Meanwhile, the superiority was also observed for restenosis at 1-year, transient ischemic attack within 30 d, and stroke/death at 4- and 10-year follow-ups.

Alternative management of the left subclavian artery in thoracic endovascular aortic repair for aortic dissection: a single-center experience

Background

Since the new 2009 guidelines for left subclavian artery (LSA) management using thoracic endovascular aortic repair (TEVAR), a few studies have been published about alternative LSA management. The objective of this study was to present the follow-up results of covered or revascularized LSA during TEVAR.

Methods

From January 2010 to August 2012, 109 consecutive patients were treated with TEVAR at the Department of Vascular Surgery, Changhai Hospital, for aortic dissection extending near the LSA. After evaluating the bilateral vertebral arteries, fifty-two LSAs were covered and not revascularized (covered group), while 57 LSAs were preserved (revascularized group). Complications were stratified according to the time of occurrence after surgery.

Results

Emergency operations were more common (17.3 vs. 3.5 %, P = 0.017) and operation time was shorter (96.9 ± 16.3 vs. 135.3 ± 38.4 min, P < 0.001) in the covered group. Pulselessness and intermittent claudication of the left arm occurred in most patients in the covered group (P < 0.001). Incidence of stroke and cold shoulder feeling were higher in the covered group compared with the revascularized group (P = 0.026 and <0.001, respectively). There were five aorta-related deaths in the covered group and one in the revascularized group. Eight endoleaks were observed in the revascularized group (P = 0.006).

Conclusions

The results of this study suggest that due to occurrence of complications, LSA should be preserved or revascularized to reduce complications and to improve patients’ quality of life.

Effectiveness of Viabahn in the Treatment of Superficial Femoral Artery Occlusive Disease

Purpose: To evaluate the effectiveness of the Viabahn stent-graft in the treatment of superficial femoral artery (SFA) occlusive disease. Methods: A systematic review and meta-analysis of published studies was performed to evaluate the efficacy of the Viabahn for SFA lesions. Studies were stratified according to controlled vs uncontrolled design and analyzed using random-effects models. Outcomes are reported as the risk ratio (RR) and 95% confidence interval (CI). Four prospective randomized controlled trials, one retrospective controlled study, and 9 uncontrolled studies were identified. Results: In controlled studies, primary patency with the Viabahn was superior to other interventions at 1 year (RR 0.63, 95% CI 0.49 to 0.82, p<0.001) and ankle-brachial index (ABI) improvement was greater at 6 months (mean difference 0.05, 95% CI 0.01 to 0.09, p=0.01) compared with other interventions. Subgroup analysis demonstrated a lower incidence of stent fracture in lesions with >15-cm stented lengths. In uncontrolled studies, ABI improvement was consistently superior at all measurement points during follow-up. Conclusions: Current evidence suggests that the Viabahn stent-graft is a safe and effective option for symptomatic SFA lesions. Prospective multicenter randomized controlled trials with long-term follow-up are needed to confirm the sustained efficacy of the Viabahn device.

Layer- and Direction-Specific Material Properties, Extreme Extensibility and Ultimate Material Strength of Human Abdominal Aorta and Aneurysm: A Uniaxial Extension Study

Mechanical analysis has the potential to provide complementary information to aneurysm morphology in assessing its vulnerability. Reliable calculations require accurate material properties of individual aneurysmal components. Quantification of extreme extensibility and ultimate material strength of the tissue are important if rupture is to be modelled. Tissue pieces from 11 abdomen aortic aneurysm (AAA) from patients scheduled for elective surgery and from 8 normal aortic artery (NAA) from patients who scheduled for kidney/liver transplant were collected at surgery and banked in liquid nitrogen with the use of Cryoprotectant solution to minimize frozen damage. Prior to testing, specimen were thawed and longitudinal and circumferential tissue strips were cut from each piece and adventitia, media and thrombus if presented were isolated for the material test. The incremental Young’s modulus of adventitia of NAA was direction-dependent at low stretch levels, but not the media. Both adventitia and media had a similar extreme extensibility in the circumferential direction, but the adventitia was much stronger. For aneurysmal tissues, no significant differences were found when the incremental moduli of adventitia, media or thrombus in both directions were compared. Adventitia and media from AAA had similar extreme extensibility and ultimate strength in both directions and thrombus was the weakest material. Adventitia and media from AAA were less extensible compared with those of NAA, but the ultimate strength remained similar. The material properties, including extreme extensibility and ultimate strength, of both healthy aortic and aneurysmal tissues were layer-dependent, but not direction-dependent.

Management of complicated aortic aneurysms using multiple overlapping uncovered stents: mid-term outcome from a cohort study

This study sought to report the mid-term outcome of a modified flow-diverting strategy in the treatment of complicated aortic aneurysms of different morphology. Historical data suggested aortic aneurysm expansion and rupture after endovascular treatment with current commercial flow-diverters, indicating the essentiality of further investigation of this technique prior to its large-scale clinical application. An alternative flow-diverting strategy using layer-by-layer assembled multiple overlapping uncovered stents was employed in this study. The treatment outcome in aneurysms of different morphology (saccular, fusiform, and dissecting) was assessed during a mid-term follow-up period.Of 42 patients enrolled in this study (30 male, mean age: 63.3 years), technical success was achieved in 40 cases. During an average follow-up period of 20.9 months, mean aneurysm diameter shrunk from 53.4 ± 13.6 mm to 48.8 ± 13.9 mm (P < 0.001), while stent-induced sac thrombosis ratio increased significantly (18.1 ± 14.9% to 93.6 ± 9.5%, P < 0.001). The majority of side branches (74/76 major visceral branches, 237/244 minor segmental arteries), covered by 3.3 stents on average, maintained their patency after stenting. Saccular aneurysms manifested the highest thrombus deposition speed (18/20 were totally thrombosed within 12 months) and most significant shrinkage (51.4 ± 13.3 mm pre-operatively vs 43.5 ± 10.2 mm during follow-up, P < 0.001) compared with fusiform and dissecting aneurysms. This modified flow-diverting strategy could be a feasible alternative in the management of complicated aortic aneurysms where vital branches need to be preserved. The treatment outcome may depend on the aneurysm type. Further studies with larger patient cohort and longer follow-up are required to substantiate these results.

Potential risk factors of re-intervention after endovascular repair for type B aortic dissections

OBJECTIVES

To assess the potential risk factors of re-intervention after thoracic endovascular aortic repair (TEVAR).

BACKGROUND

TEVAR has been chosen as a less invasive alternative for Type B aortic dissections (TBADs); however, the potential risk factors of re-intervention remain unclear.

METHODS

A total of 252 TBADs patients initially treated with TEVAR between September 1998 and July 2012 were retrospectively reviewed. The indications for the initial TEVAR were 32 aorta enlargement (24 chronic), 71 malperfusion, 46 rupture (32 chronic), 67 refractory pain (54 chronic), and 44 refractory hypertension (38 chronic). The patients were stratified into single-intervention group and multi-intervention group.

RESULTS

The mean age was 54.1 years with 81.7% of male. We found the time from symptom onset to TEVAR was longer in multi-intervention group (17 vs. 112.5 days, P = 0.006). Higher proportions of chronic dissection and smoking occurred in multi-intervention group (53.9% vs. 79.2% and 43.9% vs. 70.8%, P = 0.018 and 0.012, respectively). The differences of oversizing, operation time, contrast medium dose, and blood loss between the groups were significant (13.8 ± 2.4% vs. 16.4 ± 2.9%, 92.5 vs. 196 minutes, 110 vs. 210 ml, 100 vs. 300 ml; P < 0.001, <0.001, =0.002, and =0.003, respectively). The mortality within 30 days was 2.4% and the rates of stoke, paraplegia and retrograde dissection were 3.6%, 5.6% and 0.8%, respectively. The most common reasons of re-intervention were endoleaks, new dissections and incomplete thrombosis of the false lumen.

CONCLUSIONS

we concluded that chronic phase, smoking and too big oversizing were potential risk factors of re-intervention.

Total endovascular repair of thoracoabdominal aortic aneurysms with non-customized stent grafts

BACKGROUND

Total endovascular repair of thoracoabdominal aortic aneurysms with customized branched or fenestrated endografts could be technically challenging outside large-volume centers. This study aims to describe a new endovascular strategy for use of both noncustomized stent grafts and flow-diverting stents in treating complicated thoracoabdominal aortic aneurysms.

METHODS

Patients diagnosed with thoracoabdominal aortic aneurysms and deemed unfit for open surgical repair were recruited. The aim of the procedure was to cover the renovisceral segment of the aorta with flow-diverting uncovered stents, while covering the remaining aneurysm with stent grafts. Aneurysm morphologic evolution and the patency of the visceral branches were assessed at follow-up.

RESULTS

Between February 2012 and August 2013, 6 selective patients (4 men, mean age 58 years) underwent the novel joint procedure. During mean follow-up of 14 months, aneurysm shrinkage (maximum diameter decrease ＞5 mm) was demonstrated in 4 patients and aneurysm stabilization (maximum diameter decrease ＜5 mm) was observed in 2 patients. No aneurysm expansion was observed in any participants. Mean aneurysm diameter decreased from 65.0±8.8 mm to 58.5±12.2 mm (p=0.054), with a significant increase in average sac thrombus deposition volume (sac thrombosis ratio increased from 23.3%±7.4% to 98.0%±3.3%, p＜0.001). The majority of side branches (23 of 24) were successfully preserved.

CONCLUSIONS

Complete endovascular repair of thoracoabdominal aortic aneurysms with this novel joint procedure may be a feasible alternative in high surgical risk patients. Further validation of this technique is required to substantiate these results.

Multiple overlapping uncovered stents as an alternative flow-diverting strategy in the management of peripheral and visceral aneurysms

OBJECTIVE

In this study we aimed to report on the midterm outcome of multiple overlapping uncovered stents in the treatment of peripheral and visceral aneurysms, and analyze the possible factors affecting the treatment efficacy.

METHODS

Data of patients who were regularly followed up over 24 months were retrospectively reviewed. Descriptive statistics were applied to present aneurysm thrombosis process and diameter change at each follow-up point, and a comparison with the baseline level was performed. Patients were divided into a totally thrombosed (TT) group and a residual perfusion (RP) group according to the sac thrombosis ratio (thrombus volume to sac volume ratio) at 3, 6, and 12 months of follow-up. Aneurysm shrinkage in the two groups was compared to explore the effect of the initial RP on the treatment outcome. Patients were also grouped based on their aneurysm morphology (saccular/fusiform). The aneurysm sac thrombosis speed (time to thrombosis) and diameter decrease (DD) ratio (percentage of DD) were compared between the two groups to understand the influence of aneurysm shape on the treatment efficacy.

RESULTS

Of the 64 patients treated, the initial 37 patients (25 male; average age, 55.5 ± 13.0 years) were enrolled into this study. Technical success rate was 100%. All patients were regularly followed up. At 24 months, 94.6% aneurysms (35/37) were TT, and the maximum aneurysm diameter decreased from 36.5 ± 9.7 mm preoperatively to 23.6 ± 7.7 mm (P < .001). Overall clinical success rate (complete thrombosis and shrinkage/stabilization of the aneurysm without aneurysm-related mortality) reached 94.6% in the study cohort. Most side branches (31/33) covered by the bare stent stayed patent during follow-up. Initial sac RP at 3, 6, and 12 months might not fully affect the final aneurysm DD ratio (TT group: 0.37 ± 0.09, 0.35 ± 0.09, and 0.35 ± 0.09; compared with the RP group: 0.33 ± 0.09, 0.36 ± 0.11, and 0.36 ± 0.13; P = .153, .964, and .418, respectively). At 3 and 6 months follow-up, saccular aneurysms (n = 29) seemed to have a faster thrombosis speed compared with fusiform aneurysms (78.1 ± 26.8% and 83.9 ± 21.8% vs 47.0 ± 24.4% and 63.9 ± 22.6%; P = .004 and .013, respectively), but there was no significant difference in aneurysm shrinkage ratio at 24 months between the two groups (0.36 ± 0.10 vs 0.33 ± 0.06; P = .357).

CONCLUSIONS

Multiple overlapping uncovered stents could be a feasible option for the endovascular treatment of peripheral and visceral aneurysms. Neither the aneurysm shape nor the initial sac RP would affect the midterm treatment outcome. Further validation of this technique is required to substantiate these results.

The imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumours (pPNETs)

OBJECTIVE

To explore the imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumours (pPNETs).

METHODS

The imaging features and pathological characteristics of eight cases of surgically and pathologically confirmed Ewing sarcoma/pPNET were analysed retrospectively in light of recent literature on the disease.

RESULTS

The peak age was between 10 and 20 years. The lesions tended to be spindle shaped and dural based, usually widely so. CT showed that the lesions had slightly uneven high density in five cases and iso-low mixed density in three cases; marked heterogeneous enhancement was seen in all cases after contrast injection. MRI of the lesions showed varying proportions of isointense and hypointense signal in all cases on unenhanced T1 weighted imaging and varying proportions of isointense and hyperintense signal on T2 weighted imaging. After contrast injection, marked heterogeneous enhancement was seen in all cases; three cases showed a short and nodular dural tail and five cases showed adjacent skull erosion and osteolysis. Pathological results included high cell density, haemorrhage and necrosis. The cells resembled lymphocytes and spindle cells with transparent cytoplasm. CD99 and vimentin were expressed by all tumour cells.

CONCLUSION

Features of meningeal Ewing sarcoma/pPNETs include peak incidence at 10-20 years of age, a broad connection to the meninges, a thick dural tail involved with tumour, skull and scalp erosion and early metastasis. Necrosis and cystic changes are the common histological findings.

ADVANCES IN KNOWLEDGE

The imaging features of meningeal Ewing sarcoma/pPNETs have not been reported. The study helps to identify meningeal Ewing sarcoma/pPNETs and meningioma.

Feasibility study on energy prediction of microwave ablation upon uterine adenomyosis and leiomyomas by MRI

OBJECTIVE

To evaluate the feasibility of energy prediction of percutaneous microwave ablation (PMWA) upon uterine leiomyomas and adenomyosis by MRI.

METHODS

63 patients (49 patients with 49 uterine leiomyomas and 14 patients with adenomyosis) who underwent ultrasound-guided PMWA treatment were studied during the period from June 2011 to December 2012. Before PMWA, contrast-enhanced MRI (ceMRI) was performed for all of the patients. Based on the signal intensity (SI) of T2 weighted MRI, uterine leiomyomas were classified as hypointense, isointense and hyperintense. During ablation, the output energy of the microwave was set at 50 W, and T11a microwave antennas were used. ceMRI was performed within 7 days after PMWA treatment. Non-perfused volume and energy required per unit volume were analysed statistically.

RESULTS

When unit volume of lesions was ablated, uterine adenomyosis needed more energy than did uterine leiomyomas, and hyperintense uterine leiomyomas needed more energy than did hypointense pattern.

CONCLUSIONS

MRI SI of uterine leiomyomas and uterine adenomyosis can be used to predict PMWA energy.

ADVANCES IN KNOWLEDGE

The conclusions indicate that MRI SI can be used to perform pre-treatment planning, which will make the treatment more precise.

Transbrachial and femoral artery approach endovascular therapy for flush infrarenal aortic occlusion

OBJECTIVE

The purpose of this study is to report the efficacy of transbrachial and femoral artery approach endovascular therapy with catheter-directed thrombolysis (CDT) and adjunctive therapy for flush infrarenal aortic occlusion (FIAO).

MATERIALS AND METHODS

From March 2012 to December 2013, 11 consecutive patients (9 males; mean age 68 years; range 54-80 years) were submitted to endovascular therapy for FIAO. All patients were treated with CDT initially and then adjunctive endovascular treatments were performed to correct the underlying lesions.

RESULTS

Complete reconstruction of occluded aortoiliac arteries was successfully achieved in 81.8% (9/11) of patients. Left brachial and bilateral femoral arterial accesses were obtained in nine patients, and brachial and unilateral femoral in two patients. The residual lesions after CDT were corrected in nine patients and concomitant endovascular recanalization of superficial femoral artery was performed in two patients. Self-expandable stents were implanted in the all aortoiliac lesions with pre- and post-dilation. No renal or distal runoff embolization was seen during intraoperative angiography. Seven (7/9) patients with rest pain or tissue loss showed significant improvements in symptoms and two (2/9) patients with intermittent claudication gained an improved walking distance. The ABI rose significantly between pre- and post-procedure (0.84 ± 0.18 vs. 0.44 ± 0.13 on the right leg, p < .01; 0.89 ± 0.23 vs. 0.48 ± 0.16 on the left, p < .01).

CONCLUSIONS

Transbrachial and femoral artery approach endovascular therapy for FIAO offers an alternative to surgical reconstruction with immediate outcomes.

Genome-wide identification, characterization, and expression analysis of the MLO gene family in Cucumis sativus

Mildew resistance locus o (MLO) is a plant-specific seven-transmembrane (TM) gene family. Several studies have revealed that certain members of the MLO gene family mediate powdery mildew susceptibility in three plant species, namely, Arabidopsis, barley, and tomato. The sequenced cucumber genome provides an opportunity to conduct a comprehensive overview of the MLO gene family. Fourteen genes (designated CsMLO01 through CsMLO14) have been identified within the Cucumis sativus genome by using an in silico cloning method with the MLO amino acid sequences of Arabidopsis thaliana and rice as probes. Sequence alignment revealed that numerous features of the gene family, such as TMs, a calmodulin-binding domain, peptide domains I and II, and 30 important amino acid residues for MLO function, are well conserved. Phylogenetic analysis of the MLO genes from cucumber and other plant species reveals seven different clades (I through VII). Three of these clades comprised MLO genes from A. thaliana, rice, maize, and cucumber, suggesting that these genes may have evolved after the divergence of monocots and dicots. In silico mapping showed that these CsMLOs were located on chromosomes 1, 2, 3, 4, 5, and 6 without any obvious clustering, except CsMLO01. To our knowledge, this paper is the first comprehensive report on MLO genes in C. sativus. These findings will facilitate the functional characterization of the MLOs related to powdery mildew susceptibility and assist in the development of disease resistance in cucumber.

Endovascular SilverHawk directional atherectomy for thromboangiitis obliterans with occlusion of the popliteal artery

Thromboangiitis obliterans (TAO), also known as Buerger disease, is a nonatherosclerotic segmental inflammatory disease of small and medium-sized arteries of the distal extremities occurring predominantly in young men who are long-term tobacco smokers. We treated 2 patients who presented with TAO involving popliteal and tibial arteries. Directional atherectomy with a SilverHawk device was used to recanalize the arteries without major complications. During follow-up conducted using computed tomography or sonography, we observed that the treated vessels remained patent. These cases report illustrate the feasibility and immediate effectiveness of endovascular SilverHawk directional atherectomy in TAO patients with occlusion of the popliteal arteries.

Study of Solid-plug Conveying in a Centrifugal Extruder

A new type of polymer processing machine, a centrifugal extruder, is introduced and its performance studied experimentally and analyzed theoretically. Calculations show that by means of appropriate choice of the geometrical parameters of the rotor drum and the rotor speed, the pressure of the solid polymer in the rotor drum can reach a value of several MPa. Theoretical analysis also shows that the most important factors influencing the solid conveying pressure in the rotor drum are the radius and slope angle of the rotor drum, the rotation speed of the rotor drum, the friction factor between the solid polymer and the drum surface, and the density of the polymer. An experimental rotor drum was designed in order to validate the mathematical model used for calculation of the solid conveying pressure in the rotor drum. The results of the experiments show good agreement with the theoretical predictions.

Endovascular repair of the aortic arch in pigs by improved double-branched stent grafts

INTRODUCTION

This study aimed to evaluate the feasibility of total endovascular repair of the aortic arch in pigs using improved integrated double-branched stent grafts.

METHODS

Improved self-expandable stent grafts with a main body and two integrated branches were prepared for the repair of the aortic arch in six pigs. The feasibility of using these stent grafts was evaluated with arteriography, computed tomography (CT), computed tomography angiography (CTA) and autopsy three months following the procedure.

RESULTS

The double-branched stent grafts were placed successfully in the aortic arch in all six pigs. All pigs survived for at least three months and their biological behaviour was normal. Arteriography, CTA and animal necropsy revealed good fixation in all cases. Aortic valve function and coronary ostia remained intact, and CT of the head did not detect any lesion of cerebral infarction.

CONCLUSIONS

Endovascular repair of the aortic arch with an integrated double-branched stent graft is safe and feasible in animal studies.

Efficacy and safety of Aethoxysklerol® (polidocanol) 0.5%, 1% and 3% in comparison with placebo solution for the treatment of varicose veins of the lower extremities in Chinese patients (ESA-China Study)

Objectives

To assess efficacy and safety of polidocanol (POL) versus placebo in the treatment of C1 and C2 non-saphenous varicose veins in Chinese patients.

Methods

Patients were randomly assigned to POL or placebo. POL 0.5%, 1% and 3% were administered depending on varicose vein type. Response after 12 weeks was defined as Grade 4 or 5 on a digital imaging-based five-point scale (C1 veins) or occlusion and/or absence of reflux >0.5 second (C2 veins). Safety was evaluated with a five-point scale and standard safety assessments.

Results

Two hundred and eighty-five patients were treated. POL 0.5%, 1% and 3% were each superior to placebo ( P < 0.001); response rates: 87.1% versus 13.6%, 86.4% versus 12.5% and 88.6% versus 4.3%, respectively. Significantly more POL than placebo patients were satisfied/very satisfied with treatment. POL was well tolerated, with mostly symptoms at the injection site reported.

Conclusions

Sclerotherapy with POL 0.5%, 1% and 3% was efficacious and safe in Chinese patients.

Endovascular repair of the half aortic arch in pigs with an improved, single-branched stent graft system for the brachiocephalic trunk

The objective of this study was to evaluate the feasibility of endovascular repair of half of the aortic arch in pigs using an improved, integrated, single-branched stent graft for the ascending aorta and brachiocephalic trunk (BCT). We designed an improved stent graft in an integrated fashion and deployed the stent grafts into the ascending aortas and BCT of eight pigs. The feasibility of the stent graft deployments was evaluated three months after the procedures using arteriography, computed tomography angiography (CTA) and animal autopsy. The stent grafts were successfully deployed in eight pigs. All animals survived for at least three months. Arteriography, CTA and animal necropsy revealed good stent fixation in eight cases. Their head CT scans found no evidence of cerebral infarction. In conclusion, endovascular repair of the half aortic arch with the integrated single-branched stent graft system appears to be safe and feasible in pigs.

A microRNA profile comparison between thoracic aortic dissection and normal thoracic aorta indicates the potential role of microRNAs in contributing to thoracic aortic dissection pathogenesis

OBJECTIVES

Our aim was to identify important microRNAs (miRNAs) that might play an important role in contributing to aortic dissection by conducting a miRNA profile comparison between thoracic aortic dissection (TAD) and normal thoracic aorta.

METHODS

The differentially expressed miRNA profiles of the aortic tissue between TAD patients (n = 6) and age-matched donors without aortic diseases (NA; n = 6) were analyzed by miRNA microarray. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was further performed to verify the expression of 12 selected miRNAs with an increased number of samples (TAD n = 12; NA n = 8). The potential targets of the differentially expressed miRNAs were predicted using computational searches. Bioinformatic analyses of the predicted target genes (gene ontology, pathway and network analysis) were done for further research. Additionally, Western blotting was performed to confirm the bioinformatics findings.

RESULTS

The miRNA microarray revealed differentially expressed miRNAs between the TAD and NA groups. In the TAD group, 18 miRNAs were upregulated and 56 were downregulated (fold change >2, P < .01). qRT-PCR verified statistically consistent expression of seven selected miRNAs with microarray analysis. Combined with our previous proteomics study, target gene prediction revealed that some miRNAs reciprocally expressed with their targeted proteins. Target gene-related pathway analysis showed a significant change in five pathways in the TAD group compared with the NA group, especially the focal adhesion and the mitogen-activated protein kinase (MAPK) signaling pathways. By further conducting miRNA gene network analysis, we found that the mir-29 and mir-30 families are likely to play a role in the regulation of these two pathways, respectively.

CONCLUSIONS

Our results indicate that miRNAs expression profiles in aortic media from TAD were significantly changed. These results may provide important insights into TAD disease mechanisms. This study also suggests that the focal adhesion and MAPK signaling pathways might play important roles in the pathogenesis of TAD.