Search

Electron-doped Sr2IrO4 is the best candidate for unconventional superconductivity, but direct evidence of superconductivity has not been experimentally confirmed. Therefore, it is urgent to explore the complex and rich physical properties caused by doping. The planar Hall effect (PHE) is a sensitive technique for the characterization of intrinsic magnetic properties in magnetic thin films and is applied widely in spintronic devices. In this work, the PHE for La-doped Sr2IrO4 films as a function of the magnetic field direction and temperature exhibited unique properties caused by electron doping. The amplitude of PHE is proportional to the strength of the applied magnetic field. Remarkably, as the temperature increased, a sign reversal of angle-dependent PHE occurred at 90 K, which indicated the change of magnetic anisotropy. Subsequent variable-temperature traditional Hall measurements and time-resolved optical studies eliminated different types of carrier interactions. The anisotropic magnetoresistance measurements indicated that the sign reversal can be attributed to the changes of a spin structure after electron doping, and the reversal temperature is related to the strength of ferromagnetism. These results provide a platform to study the magnetic interactions and suggest the possibility of realizing thermal controllable magnetic sensor devices in electron-doped Sr2IrO4 films.

Dysfunction of endothelial cells (ECs) contributes to restenosis after vascular reconstruction for patients with coronary artery disease (CAD). The intercellular communication between ECs and vascular smooth muscle cells (VSMCs) might be critical in the development of restenosis and can be mediated by exosomes carrying functional microRNAs. miR-185 is reported to be associated with atherosclerosis, whether it plays a similar role in restenosis is unknown. In this study, we observed an elevated level of extracellular miR-185 in platelet-derived growth factor (PDGF)-stimulated VSMCs. The medium from PDGF-stimulated VSMCs promoted miR-185 expression in rat aortic ECs and inhibited EC angiogenesis. PDGF-stimulated VSMCs transferred miR-185 into ECs via exosomes. Furthermore, we found that the CXCL12 gene, a target of miR-185, is essential for the angiogenic potential of ECs. Exosomes derived from miR-185 mimic transfected VSMCs attenuated re-endothelialization after vascular injury. Moreover, we show that exosome-mediated miR-185 transfer is modulated by hnRNPA2B1. We also observed that hnRNPA2B1 is up-regulated during neointima formation and hnRNPA2B1 inhibition accelerates re-endothelialization and attenuates neointima formation following carotid injury. Taken together, our results indicate that exosomal miR-185 transfer from VSMCs to ECs is controlled by hnRNPA2B1 and impairs re-endothelialization after vascular injury.

Significance Light-driven rhodopsin proteins pump ions across cell membranes. They have applications in optogenetics and can potentially be used to develop solar energy–harvesting devices. A detailed understanding of rhodopsin dynamics and functions may therefore assist research in medicine, health, and clean energy. This time-resolved crystallography study carried out with X-ray free-electron lasers reveals detailed dynamics of chloride ion–pumping rhodopsin (ClR) within 100 ps of light activation. It shows the dissociation of Cl− from the Schiff base binding site upon light-triggered retinal isomerization. This Cl− dissociation is followed by diffusion toward the intracellular direction. The results hint at a common ion-pumping mechanism across rhodopsin families., Chloride ion–pumping rhodopsin (ClR) in some marine bacteria utilizes light energy to actively transport Cl− into cells. How the ClR initiates the transport is elusive. Here, we show the dynamics of ion transport observed with time-resolved serial femtosecond (fs) crystallography using the Linac Coherent Light Source. X-ray pulses captured structural changes in ClR upon flash illumination with a 550 nm fs-pumping laser. High-resolution structures for five time points (dark to 100 ps after flashing) reveal complex and coordinated dynamics comprising retinal isomerization, water molecule rearrangement, and conformational changes of various residues. Combining data from time-resolved spectroscopy experiments and molecular dynamics simulations, this study reveals that the chloride ion close to the Schiff base undergoes a dissociation–diffusion process upon light-triggered retinal isomerization.

Objectives The aim of the present study was to review our institutional experience of endovascular treatment for isolated subclavian artery aneurysms and evaluate the long-term outcomes. Methods A retrospective review of all patients with isolated subclavian artery aneurysms who underwent endovascular treatment between March 2008 and March 2020 was performed. The demographics, aneurysmal characteristics, treatment strategies, and in-hospital and follow-up outcomes were recorded and then analyzed. Results From March 2008 to March 2020, 35 isolated subclavian artery aneurysms were endovascularly treated at our institution. Atherosclerosis was the most common cause of aneurysms in this series. Most aneurysms were intrathoracic (91.4%) and located at the right side (77.1%). There were 26 true aneurysms, seven pseudoaneurysms, and two ruptured isolated subclavian artery aneurysms. Five types of endovascular strategies were performed. Covered stent placement across the aneurysm was the most (54.3%) commonly used method. Technical success was achieved in all patients. The median postoperative in-hospital stay was 4.0 days (range, 1–15 days). One patient died after discharge but within 30 days of surgery due to myocardial infarction. The median follow-up time was 62.0 months (range, 3–132 months). No death, stroke, stent fractures, or severe upper limb ischemia developed during the follow-up period. The cumulative survival rate at five years was 97.1%. The overall complication rate was 25.7% and one-third of complications (8.6%) required reinterventions. Conclusions Endovascular treatment for isolated subclavian artery aneurysms is safe, effective and technically achievable in most patients. Short- and long-term outcomes are promising. Reasonable and flexible use of covered stents can also get satisfactory outcomes in some complicated lesions such as isolated subclavian artery aneurysms located at the origin of the right subclavian artery, avoiding the huge surgical trauma caused by conventional open repair.

Intercellular communication between mesenchymal stem cells (MSCs) and their target cells in the perivascular environment is modulated by exosomes derived from MSCs. However, the potential role of exosome‐mediated microRNA transfer in neointimal hyperplasia remains to be investigated. To evaluate the effects of MSC‐derived exosomes (MSC‐Exo) on neointimal hyperplasia, their effects upon vascular smooth muscle cell (VSMC) growth in vitro and neointimal hyperplasia in vivo were assessed in a model of balloon‐induced vascular injury. Our results showed that MSC‐Exo were internalised by VSMCs and inhibited proliferation and migration in vitro. Further analysis revealed that miR‐125b was enriched in MSC‐Exo, and repressed the expression of myosin 1E (Myo1e) by targeting its 3ʹ untranslated region. Additionally, MSC‐Exo and exosomally transferred miR‐125b repressed Myo1e expression and suppressed VSMC proliferation and migration and neointimal hyperplasia in vivo. In summary, our findings revealed that MSC‐Exo can transfer miR‐125b to VSMCs and inhibit VSMC proliferation and migration in vitro and neointimal hyperplasia in vivo by repressing Myo1e, indicating that miR‐125b may be a therapeutic target in the treatment of vascular diseases.

IntroductionInferior vena cava (IVC) filters are commonly used in patients with venous thromboembolism to prevent fatal pulmonary embolism, but the thrombosis risk increases after filter placement. Warfarin is a widely anticoagulant, but long-term monitoring and dose adjustments are required. Anticoagulation with rivaroxaban is more straightforward as it dose not require laboratory monitoring. This study compares the efficacy and safety of rivaroxaban and warfarin as an in anticoagulation therapy for patients with IVC filter placement.Methods and analysisThis is a multicentre, randomised controlled trial. In total, 200 patients with deep vein thrombosis (DVT) with IVC filter implantation from 10 hospitals will be recruited. The patients will be randomised to the experimental group (rivaroxaban) or the control group (nadroparin overlapped with warfarin). The primary outcomes include death of any cause, pulmonary embolism (PE)-related death, bleeding and recurrent PE/DVT. The secondary outcomes include the percentage of other vascular events, IVC filter retrieval failure and net clinical benefits. This study aims to provide reliable, verification for the efficacy and safety of rivaroxaban antithrombotic therapy after IVC filter placement.Ethics and disseminationThe study was approved by the Human Research Ethics Committee of the Second Affiliated Hospital of Zhejiang University School of Medicine (approval number: (2019) 295). The results will be disseminated through presentations at scientific conferences and publications in peer-reviewed journalsTrial registration numberNCT04066764.

Objective The objective of this study was to evaluate the safety, efficacy, and outcomes of the conformable thoracic endograft (Conformable TAG Thoracic Endoprosthesis [CTAG]; W. L. Gore & Associates, Flagstaff, Ariz) for acute complicated and uncomplicated type B aortic dissection (TBAD). Methods Between February and October 2016, 52 consecutive patients with acute complicated or uncomplicated TBAD were treated with a CTAG device. We assessed safety, complications, and device conformability using intraoperative angiography and computed tomography angiography. The mean follow-up period was 8.2 ± 3.5 months (range, 4-12 months). Results All patients survived through the follow-up period. No endoleaks, retrograde aortic dissection, distal new entry tear, stroke, or paraplegia was observed postoperatively. Two patients (3.8%) experienced minor wound hematomas without further treatment. Eleven patients (21.2%) underwent a chimney technique to rebuild supra-arch vessels. A bird-beak configuration was observed in seven (13.5%) patients, five of whom underwent a chimney technique. Analysis of aortic remodeling showed that the minimal true lumen area significantly increased in both complicated and uncomplicated acute TBAD ( P P = .047, respectively). Likewise, the maximal false lumen area significantly decreased in uncomplicated dissection ( P = .006), but no change in maximal false lumen area was detected in complicated dissection ( P = .32). Conclusions Early outcomes indicate that the CTAG device provides reliable clinical effectiveness and excellent conformability in treating acute complicated and uncomplicated TBAD without risk of major complications. Studies with larger sample sizes and longer follow-up periods are required to evaluate longer term outcomes.

Introduction The nerve fibers innervating the annulus fibrosus are the major origin of degeneration-associated discogenic pain. Coblation is a tissue-dissociating technique in which the nerve fibers in the degenerative disc tissue are ablated. We hypothesized that coblation annuloplasty would be an effective maneuver for cervical discogenic pain without radiculopathy. Aim To observe the therapeutic efficacy of coblation annuloplasty in patients with cervical discogenic pain without radiculopathy. Material and methods Forty patients diagnosed with cervical discogenic pain without radiculopathy were screened for coblation annuloplasty therapy. The patient-rated visual analog scale (VAS) score for pain, significant pain relief rate, and Modified MacNab pain-relieving effect were adopted to evaluate the therapeutic effect within a 1-year follow-up period. Results Thirty-three patients eventually completed the study. The average pain duration was 4.6 ±1.6 years (range: 0.5-8 years). The mean VAS pain score decreased from preoperative 6.8 ±0.9 to postoperative 2.5 ±1.3 (p < 0.01). For all participants, the immediate pain relief rate was 78.7% (26/33), which continued to postoperative 6 months. One year later, 22 (66.6%) subjects reported that their pain was significantly alleviated. According to the Modified MacNab criteria, 63.6-82.1% considered the effect of surgery for their pain therapy as "excellent" during the 1-year follow-up period. No significant complications such as hemorrhage, paresthesia, or infection were observed. Conclusions This study is the first to demonstrate that coblation annuloplasty is an effective intervention providing significant alleviation of neck pain from cervical discogenic injury without radiculopathy.

Background The perfused elastase AAA model and subcutaneous Angiotensin II infusion AAA model are widely used murine AAA models. We modified these two current models and developed a new murine model to study aneurysm formation and rupture. Methods The murine abdominal aorta was treated with elastase. Angiotensin II was infused at a dose of 1,000 ng/kg/min via an osmotic pump placed subcutaneously. A saline osmotic pump was used as the control. The aortas were harvested from the mice 4 weeks later, or earlier if mice died. The abdominal aorta was inspected using ultrasound and microscopy for aneurysm formation and/or signs of rupture. The aneurysm outcome was measured using aortic expansion and proinflammatory cytokine expression. It was also compared with the established conventional elastase perfusion and angiotensin II infusion abdominal aortic aneurysm models. Results By day 28 after surgery, all abdominal aortas of mice treated in the modified group had dilated and progressed to abdominal aortic aneurysms with 60% ruptured aneurysms, whereas none of the control aortas treated with saline became aneurysmal. In mice treated with elastase solution alone, 100% developed aneurysms and only one had a ruptured aneurysm. In mice given angiotensin II infusion alone, 37.5% developed aneurysms and none had a ruptured aneurysm. Histological examination of the modified murine abdominal aortic aneurysm rupture model was identical to that observed in the conventional elastase model. Quantitative polymerase chain reaction analysis revealed similarly increased levels of proinflammatory cytokines. Conclusions We modified two current murine abdominal aortic aneurysm models to develop a murine abdominal aortic aneurysm model with consistent aneurysm formation and high rupture incidence, which can be used for studying abdominal aortic aneurysm rupture and treatment.

Heading aims Abdominal aortic aneurysm (AAA) is featured by the growth impediment and apoptosis surge of VSMCs (vascular smooth muscle cells). MicroRNAs (miRNAs) are suggested to affect cellular behaviors including cell growth and apoptosis. This study concentrated on unraveling the emerging role of miR-28-5p in abdominal aortic aneurysm. Materials and methods Previously, miR-28-5p was reported to be highly expressed in AAA. Functional assays were utilized to determine the role of miR-28-5p in VSMC apoptosis. To narrow down the downstream mRNAs, bioinformatics methods were utilized. The interaction between miR-28-5p and GRIA4 (glutamate ionotropic receptor AMPA type subunit 4) or LYPD3 (LY6/PLAUR domain containing 3) was explored. Candidate circRNAs (circular RNAs) of miR-28-5p were identified. Rescue analyses validated function of circCBFB (core-binding factor subunit beta)/miR-28-5p/GRIA4/LYPD3 axis in VSMC apoptosis and growth. Key findings MiR-28-5p acted as an apoptosis driver while circCBFB, GRIA4 and LYPD3 exerted anti-apoptosis effects in VSMCs. Mechanically, GRIA4 and LYPD3 were suppressed by miR-28-5p. Moreover, circCBFB served as a sponge of miR-28-5p, releasing GRIA4 and LYPD3 from miR-28-5p suppression. Functionally, GRIA4, LYPD3 and miR-28-5p were required in circCBFB-mediated VSMC apoptosis. Significance This work unveiled an innovative axis of circCBFB/miR-28-5p/GRIA4/LYPD3 in VSMC apoptosis, exerting its potential in providing new thoughts in AAA management.

Background Podocyte injury was reported to be involved in the major pathogenesis of ischemia/reperfusion (I/R)-induced ischemic acute renal failure. Our purpose was to study the mechanism of miR-187 improving I/R-induced podocytes injury. Materials and methods The miR-187 mimics and inhibitor were transfected into the immortalized mouse podocyte (MPC-5) cells, and then transfected cells were subjected to hypoxia/reoxygenation (H/R, 3/3 h) to establish an H/R cell model. To investigate the effects of miR-187 on H/R-induced cell injury, cell viability and apoptosis were measured by Cell Counting Kit-8 (CCK-8) assay and flow cytometry. Dual-luciferase report system was used to verify whether miR-187 could directly target acetylcholinesterase (ACHE). The animal ischemia/reperfusion model was established and injected with miR-187 agomir. Kidney tissue sections were subjected to histological examination by hematoxylin and eosin staining to assess the renal injury. Real-time quantitative PCR and western blot were performed to determine gene expressions. Results The transfection of miR-187 mimics contributed to MPC-cells resistance to H/R-induced cell injury, which was reflected by enhanced cell viability and reduced apoptosis (from 20.05% to 9.43%) in H/R + negative control group. ACHE was confirmed as a target of miR-187, and ACHE siRNA had a similar efficiency to miR-187 mimic. The injection of miR-187 agomir not only effectively protected the kidney from I/R-induced injury, but also reduced the concentrations of serum creatinine. Moreover, nephrin was noticeably increased and desmin was decreased under the effects of agomir. Conclusions Our findings indicated that miR-187 improved I/R-induced ischemic acute renal failure through protecting glomerular filtration barrier by blocking the expression of ACHE.

Background: To report the experience of a single centre regarding the application of the triple-chimney technique using C-TAG with Viabahn or Excluder iliac extension devices for the endovascular management of aortic arch dilation diseases. Methods: From July 2016 to August 2017, 7 patients (5 men; mean age 56.1±10.8 years) with aortic arch dilation diseases were treated with the triple-chimney technique. All patients were followed up at 1, 3, and 6 months and every 6 months thereafter. Results: Six innominate arteries were deployed with Excluder iliac extensions and one with a Viabahn cover-stent. All the left common carotid arteries and left subclavian arteries were placed with Viabahn. Reverse chimney technique was applied in four patients. Three (42.0%) type I endoleaks were found on the final angiogram. Two were apparently reduced, and one disappeared after balloon dilation. The mean follow-up time was 15.7 months (9–20 months). All the type I endoleak was found disappeared within 3 months. One patient died of myocardial infarction at 6 months after discharge. No other complications such as stent-graft migration, occlusion, type II endoleak or neurological stroke occurred. Conclusions: The use of C-TAG coupled with Viabahn or Excluder iliac extension is feasible and effective for the treatment of aortic arch dilatation diseases. However, more patients and longer follow-up time are required to verify its long-term safety and efficacy.

We demonstrate the simultaneous generation of multicolor femtosecond laser pulses in a 0.5 mm Type I BBO crystal from 1028 nm fundamental and weak near-IR supercontinuum of a Yb:KGW ultrafast Yb based laser. The multicolor broadband laser pulses observed are attributed to cascaded four-wave mixing (CFWM) processes. A set of spatially separated CFWM sideband signals with second harmonic-generation and sum-frequency-generation pulses are arose from the interaction between the two pulses intersect at a certain angle. The CFWM sideband signals can be changed by rotating the BBO crystal to achieve the phase matching condition and adjusting the time delay between the two incident pulses to change the time overlapping.

Background Crossover stenting across the origin of the profunda femoral artery (PFA) and occasionally into the common femoral artery (CFA) is commonly used after suboptimal balloon angioplasty of ostial occlusive lesions of the superficial femoral artery (SFA) involving the bifurcation. Late stent occlusion at the bifurcation is not rare and results in severe lower extremity ischemia. Therefore, we tried to assess its possible causes, prevention and reintervention. Methods Using a prospectively maintained single-center database, 12-month femoral bifurcation patency was retrospectively compared and lesion and procedural predictors of stent occlusion were determined among 63 patients (64 lesions) who between July 2011 and February 2013 underwent crossover (36 non-jailed and 15 jailed SFA, and 12 distal and 1 complete CFA) stenting of de novo ostial SFA lesions. Results Twelve-month overall patency rate at the femoral bifurcation was 88%, with no significant difference between jailed-ostial SFA (80%) and distal CFA (67%) stenting (P = 0.731), and significant differences between either and non-jailed ostial stenting (100%, P = 0.035 and 0.002). When PFA ostium was jailed by the stent, patients with preexisting CFA or PFA lesions had a 12-month bifurcation patency rate of 20%, significantly lower than those with simple ostial SFA lesions (83%, P = 0.015). Stent induced intimal hyperplasia caused bifurcation occlusion in 6 surgical reintervention cases. Conclusions In crossover stenting of ostial lesions in SFA, bifurcation patency loss was significantly higher in distal CFA and jailed ostial SFA stenting than non-jailed ostial SFA stenting. Preexisting CFA or PFA lesion is a significant risk factor for bifurcation patency loss when PFA ostium is jailed by crossover stenting.

Abstract. Background: The objective was to explore the outcomes and aortic remodelling after proximal thoracic endovascular aortic repair (TEVAR) in post type B aortic dissection thoracic aneurysm with a maximal diameter ≥ 5.5cm. Patients and methods: 34 cases of type B aortic dissection thoracic aneurysm undergoing proximal TEVAR (coverage of the primary entry and the aneurysm extent) from 2008 to 2013 were retrospectively reviewed with follow-up for at least 2 years. The primary endpoints were 30-day mortality and survival at 2 years. The secondary endpoints were major complication and re-intervention. The aortic remodelling was investigated by comparison of the maximum diameter of the aneurysm and the diameter of true and false lumen at the same level between baseline and 2 years after TEVAR. Besides, we also analysed the possible relevant factors of aortic remodelling including the course of dissection, the involvement of dissection, and the length and shape of the stent graft. Results: The 30 day mortality was 2.9 % (1/34). The paraplegia rate post-TEVAR was 2.9 % (1/34). Overall, 32 out of the 34 cases were followed-up for 24 - 79 months. At 2 years, the overall and aortic specific survival were 87.5 % and 90.3 % respectively. The two year freedom from re-intervention rate was 87.5 %. Compared to the preoperative data, maximum diameter of descending aorta at 2 years demonstrated a slight increase (65.4±14.1mm Vs 63.9±9.1mm), but without significance (P>0.05). Meanwhile, we noticed a significant increase of true lumen (P < 0.01) and decrease of false lumen (P < 0.01) at the same level. Relevant analysis showed that positive aortic remodelling of the maximum diameter was associated with chronic phase (≥ 90 days of dissection onset) (P < 0.05) and the application of 150 - 170mm stent grafts (P < 0.05). Conclusions: Proximal TEVAR of post type B dissection thoracic aneurysm had generally favourable short- and mid-term outcomes with low paraplegia rate. Besides, it can achieve a certain extent of aortic remodelling.

To evaluate the value and clinical effect of peripheral aneurysms with polytetrafluoroethene (PTFE) stent graft after peripheral endovascular procedures.From May 2012 to November 2013, 13 patients of peripheral aneurysms were treated with PTFE stent graft. There were 9 male and 4 female patients, aged from 24 to 74 years with a mean of 52 years. There were 7 aneurysms and 6 pseudoaneurysms. This stent graft was a self-expanding nitinol stent, internally covered by an ultra-thin polytetrafluoroethene (PTFE) graft. All peripheral aneurysms were repaired with the PTFE stent graft, using an entirely percutaneous approach. All patients were given clopidogrel and (or) aspirin postoperatively. Complications and reintervention rates were also examined.PTFE stent graft placement was successfully performed in all the 13 cases, and the instant isolation effect was quite satisfactory. During the follow-up period of 3 to 18 months, no stent graft related complications occurred in all patients except one patient with iliac arterial pseudoaneurysm, who developed pseudoaneurysms presented as a complication at puncture site. There were no other symptomatic complications with graft patience.Endovascular repair can be considered as an effective treatment strategy for peripheral aneurysms by PTFE stent graft.

Background: Early treatments are profoundly beneicial and improve outcomes in peripheral arterial disease (PAD). However, asymptomatic patients do not receive the optimal treatments as early as patients with CAD. So far, the changes in the vasomotor function with the chronic occlusion of the supericial femoral artery (SFA) are still unknown. We evaluated endothelium function for both conduit and collateral resistance arteries (CA) following long-term SFA ligation in Yucatan miniswine.

Background: TAVI is by now a valid therapeutic option in elderly patients (pts) with severe symptomatic aortic stenosis considered at high risk or with contraindication to aortic valve replacement (AVR). The impact of postprocedural leaks on mortality is still debated. Methods: Since May 2008 to July 2011, 100 consecutive pts underwent TAVI (60 Edwards Sapien Valve, 40 CoreValve). Transthoracic echocardiogram (TTE) was performed before discharge and after 3 months. Prosthesis insufficiency (PI) was considered significant if at least mild according to ASE and EAE recommendations. The aim of the study is to evaluate the effect of postprocedural periprosthetic and intraprosthetic leaks on mortality. Results: Retrograde approach was performed in 67 pts, while 33 pts benefited from the transapical access. Predischarge TTE was performed in all pts, and 24 had at least mild PI: 17 (70.8%) periprosthetic, 3 (12.5%) intraprosthetic, and 4 (16.7%) mixed. VARC mortality was 15%. At 3-month follow-up (range 36–126 days), all 85 alive pts underwent a TTE at our institution. Significant leaks were found in 24 (28.2%) pts: 18 (75%) periprosthetic, 1 (4.2%) intraprosthetic, and 5 (20.4%) mixed. The univariate analysis with Yatescorrected χ showed that postprocedural PI affects 1-year mortality (RR 2.68, IC 1.39–5.18, P=.009). Subgroups analysis showed an increased incidence of leaks in CoreValve group compared to the Edwards Sapien group (28/36 vs. 24/49, P=.02). Conclusion: Periprosthesis leaks, affected also by prosthesis choice, increase 1-year mortality in patients undergoing TAVI. These data confirm the actual limits of this procedure compared to AVR. In the near future, new technologies and devices could help to improve results.

Effects of circumferential stretch vs. deep injury on the in-stent neointimal formation in the atherosclerotic iliac rabbit arteries Jianing Yue , Takamitsu Nakamura, Yuqi Wang , Weiguo Fu, Dongming Guo , Nicolas Chronos c Vascular Surgery Department of Zhongshan Hospital Fudan University, Shanghai, China Department of Internal Medicine II, University of Yamanashi, Chuo, Japan Saint Joseph's Translational Research Institute, Atlanta, GA, USA

Background: Drug-eluting bioabsorbable stents (DEBSs) represent a new device-based therapy for coronary artery disease. It has been reported that the stented segment becomes re-endothelialized after 1 month and the segments proximal and distal to the stented site are functional at 2 years. In order to examine whether after complete degradation the DEBS site function was similar to the unstented segments, we performed ex vivo vasomotor function studies using pig coronary arteries. Methods: Eighteen months after implantation in the pig coronary arteries, 10 DEBS sites [four left anterior descending (LAD), four right coronary, and two left circumflex arteries] were assessed for vasomotor function using an organ chamber apparatus. They were stimulated with potassium chloride (KCl), prostaglandin2α (PGF), and three concentrations of endothelin-1 (ET). Endothelium-dependant relaxation (EDR) to substance P (SbP; 0.01–100 pM) and endothelium-independent relaxation (EIDR) to sodium nitroprusside (SNP; 0.001–10 μM) were assessed following constriction with PGF. Remaining stent segments were fixed for histologic examination. Results: DEBS sites showed rapid response to low and high concentrations of KCl, PGF, and ET. EIDR showed concentration-dependent relaxation to SNP (13.3±4.3%, 21.3±5.6%, 52.7±7.1%, 85.5±5.4%, and 100±0%). However, there was no EDR to SbP concentration-dependent stimulation. Hematoxylin/eosin and Verhoeff–Masson staining showed evidence of smooth muscle cell (SMC) migration across polymer struts, and formation of a new abluminal layer was observed. There was complete polymer strut degradation, infiltration of inflammatory cells, and minor fibrosis around some DEBS sites. Myocardial degeneration (∼1×1.5 cm) was found in the septum adjacent to the stented LAD sites (n=4). Vessel wall within the stented segment was thicker and the lumen was narrower than in the proximal and distal segments. Conclusion: During DEBS degradation period, medial SMCs migrate to the neointima developing new layers. We have demonstrated for the first time the ex vivo contraction and relaxation responses at DEBS sites to vasoactive agents after complete degradation of the stent. SMCs recovered contractile and relaxing capabilities in this segment but endothelial function was still impaired.

Background: Transcatheter delivery of thrombolytic therapy is an effective tool in the treatment of acute deep venous thrombosis (DVT). We sought to determine an effective and safe thrombolytic regimen with tPA in the treatment of severe DVT when used in conjunction with percutaneous endovenous intervention (PEVI). Methods: Eighty consecutive patients with acute symptomatic DVT were randomized to receive four different doses of tPA. They had all undergone PEVI from 0.5 to 18 h following presentation to the hospital. PEVI consisted of any or a combination of the following: Trellis, Angiojet, or manual suction thrombectomy, balloon venoplasty, or stenting. Following initial PEVI, if N50% thrombus remained, tPA was given via an infusion catheter for 16–20 h. Patients were randomized to receive tPA at 0.5, 1, 2, or 4 mg/h and were assigned to Groups I–IV, respectively, with 20 in each group. Warfarin was continued, and during tPA administration heparin dose was reduced to 12 U/kg per hour. The end points evaluated were venous patency post-tPA (b5% residual thrombus), bleeding, and length of hospital stay. Results: The results are demonstrated in the Table 1. Venous patency rate was similar in Groups II–IV. Bleeding was seen more in Group IV, lengthening hospital stay. Venous patency was low in Group I. Conclusions: We conclude that transcatheter endovenous administration of tPA following suboptimal PEVI at 1 mg/h for 16–20 h is highly safe and effective in the treatment of DVT allowing for high patency rate, no complications, and early discharge.