Angioplasty Site Research Articles

Intravascular delivery of an MK2 inhibitory peptide to prevent restenosis after angioplasty

Peripheral artery disease is commonly treated with balloon angioplasty, a procedure involving minimally invasive, transluminal insertion of a catheter to the site of stenosis, where a balloon is inflated to open the blockage, restoring blood flow. However, peripheral angioplasty has a high rate of restenosis, limiting long-term patency. Therefore, angioplasty is sometimes paired with delivery of cytotoxic drugs like paclitaxel to reduce neointimal tissue formation. We pursue intravascular drug delivery strategies that target the underlying cause of restenosis - intimal hyperplasia resulting from stress-induced vascular smooth muscle cell switching from the healthy contractile into a pathological synthetic phenotype. We have established MAPKAP kinase 2 (MK2) as a driver of this phenotype switch and seek to establish convective and contact transfer (coated balloon) methods for MK2 inhibitory peptide delivery to sites of angioplasty. Using a flow loop bioreactor, we showed MK2 inhibition in ex vivo arteries suppresses smooth muscle cell phenotype switching while preserving vessel contractility. A rat carotid artery balloon injury model demonstrated inhibition of intimal hyperplasia following MK2i coated balloon treatment in vivo. These studies establish both convective and drug coated balloon strategies as promising approaches for intravascular delivery of MK2 inhibitory formulations to improve efficacy of balloon angioplasty.

Abstract 11635: Device and Formulation Optimization for MK2 Inhibition and Restenosis Prevention at Sites of Peripheral Angioplasty

Introduction: Peripheral angioplasty often fails due to intimal hyperplasia (IH), where contractile smooth muscle cells (SMCs) de-differentiate into proliferative, migratory, and pro-inflammatory synthetic SMCs, leading to restenosis. We have formerly shown that potentiation of an MK2 inhibitory peptide (MK2i) via delivery with poly(propyl acrylic acid) (PPAA) can block SMC phenotype switching and neointima formation in a transplant model. This work develops strategies for targeted in vivo MK2i+PPAA delivery to the site of angioplasty. Hypothesis: MK2i+PPAA can be effectively delivered into and retained within the arterial wall using either convective delivery or a coated angioplasty balloon. Methods: These studies have utilized isolated rat aortae as a model tissue. Aortae were balloon damaged and subjected to convective or coated balloon treatment. Delivery and retention of MK2i was determined with confocal microscopy and flow cytometry. MK2i activity was measured using IHC and western blots for pCREB, a downstream substrate of MK2. Results: Convective delivery studies have shown substantial MK2i delivery into the vascular wall, with pre-formed MK2i nanopolyplexes (NPs) having significantly more cell uptake than free MK2i or sequentially delivered PPAA and MK2i. Additionally, we have created a method for layered coating of MK2i+PPAA onto an angioplasty balloon that shows rapid release and successful arterial wall delivery. In efficacy studies, convective delivery of MK2i-NPs and balloon delivery of MK2i+PPAA with 50 mg/mL lactosucrose excipient significantly decreased levels of pCREB downstream of MK2 after balloon damage. Ongoing studies show that both delivery strategies block cellular proliferation in balloon damaged arteries after 7d in a flow loop bioreactor. Conclusions: Convective and coated balloon delivery show promise as strategies for on-target delivery of MK2i+PPAA to peripheral arteries after angioplasty to prevent restenosis.

Safety and functional outcomes of early antiplatelet therapy within 24 hours following mechanical thrombectomy for secondary prevention in emergent large-vessel occlusion strokes: a registry study.

The aim of this study was to demonstrate the safety and functional outcomes of antiplatelet use within 24 hours following mechanical thrombectomy (MT). A retrospective review of prospectively collected data for consecutive patients who underwent MT for acute ischemic stroke (AIS) between 2016 and 2020 was performed. Patient demographics, comorbidities, Alberta Stroke Program Early CT Score (ASPECTS), antiplatelet use, neurological status, and tissue plasminogen activator use were collected. Patients were stratified into two groups, early (< 24 hours) or late (> 24 hours), based on when antiplatelet therapy was initiated post-MT. The primary outcome was safety, determined based on the rate of symptomatic intracranial hemorrhage (sICH) and inpatient mortality. The secondary outcome was functional independence (defined as modified Rankin Scale [mRS] score ≤ 2) at discharge and 30 days and 90 days postoperatively. The two cohorts were compared using univariate analysis. Multiple imputations were used to create complete data sets for missing data. Multivariable analysis was used to identify predictors for sICH and functional outcomes. A total of 190 patients met inclusion criteria (95 per group). Significant differences between the early and late groups included sex, preoperative intravenous thrombolysis, angioplasty, stent placement, and thrombectomy site. ICH (symptomatic and asymptomatic) and inpatient mortality were not significantly different between the groups. The mRS score was significantly lower at discharge (p < 0.001), 30 days (p = 0.011), and 90 days (p = 0.024) following MT in the early group. Functional independence was significantly higher in the early antiplatelet group at discharge (p = 0.015) and at 30 days (p = 0.006). Early antiplatelet use was independently associated with significantly increased odds of achieving functional independence at discharge (OR 3.07, p = 0.007) and 30 days (OR 5.78, p = 0.004). Early antiplatelet therapy was not independently associated with increased odds of sICH. Early antiplatelet initiation after MT in patients with AIS was independently associated with significantly increased odds of improved postoperative functional outcomes without increased odds of developing sICH.

Presentation and Management of Acute Limb Ischemia Following Lower Extremity Revascularization: Insights from the VOYAGER PAD Trial

Acute limb ischemia (ALI) is a major adverse limb event associated with high morbidity and mortality. Despite the severity of this outcome, there are few large datasets including adjudicated ALI outcomes that have elucidated treatment approaches and outcomes after ALI. Data describing the presentation, initial care, and subsequent antithrombotic prophylaxis in patients with ALI after lower extremity revascularization (LER) for symptomatic peripheral artery disease (PAD) would provide valuable insights. The VOYAGER PAD trial randomized patients with PAD after LER to rivaroxaban 2.5 mg twice daily plus aspirin or matching placebo plus aspirin and followed for a median of 28 months. Patients were randomized across 34 countries. Site-reported ALI was independently adjudicated by a clinical events committee. Each event was categorized by trained vascular specialists for etiology, relationship to index or subsequent LER, inpatient therapy, discharge treatment strategy, and hospital outcomes. Of the 6564 randomized patients, 390 (5.9%) had 516 total ALI events during follow-up. ALI etiology was in situ thrombosis in 97.8%, embolism from nonextremity source in 1.9%, and undetermined in 0.3%. Anatomic location was prior bypass in 49%, arterial stent in 31%, and native arterial segment (of these, three-quarters were prior endarterectomy, atherectomy, or angioplasty sites) in 18%. Fifty-eight percent of ALI were related to the index LER, 36% were related to a prior or subsequent nonindex LER, and 6% were at a non-LER arterial site. The initial intervention strategy (Fig 1) was thrombectomy in 41% (three-quarters were open and 71% required an additional open/endovascular revascularization or major amputation at some point in hospitalization). Thrombolysis was the initial strategy in 19% and 76% of these underwent an additional open/endovascular revascularization or major amputation during the hospitalization. Median hospital stay was 6 days. Fasciotomy occurred in 6% of patients, severe complications (ventilator, shock, or dialysis) occurred in 4%, major amputation in 13%, and mortality in 2.3%. Discharge antithrombotic background therapy (excluding study drug) was variable (Fig 2). ALI in the post-LER setting is frequent and largely in-situ thrombosis at the site of prior LER. Presentation with ALI is associated with prolonged hospitalization, the need for procedures and/or amputation and high inpatient mortality. Initial therapeutic approaches in patients presenting with ALI are varied as are approaches to thromboprophylaxis. These observations highlight the need for future research investigating the optimal approach to treating patients with ALI and therapeutic strategies to prevent recurrent complications.Fig 2Discharge Anti-Thrombotic Regimen.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Notre ennemi : le caillot. Thrombose coronaire : stratégie et arsenal thérapeutique

Intra coronary thrombus is frequently encountered during acute coronary syndromes revascularisation procedures. It can also be encountered during angioplasty procedures in a stable angina context, although at a much lesser frequency.In both situations, it harbors a risk of poor angiographic result and poor prognosis. Intracoronnary thrombus may cause coronary occlusion at the angioplasty site or distal embolic flow obstruction. Per procedure thrombus prevention rests on an prior optimal anti thrombotic treatment and in some circumstances the choice to defer the revascularisation procedure in the complex high risk setting. Treating the initiated thrombus remains controversial concerning thrombectomy and GPIIBIIIa inhibitors which are still in use in common practice. No reflow phenomenon is a particularly complex setting during cornary angioplasties, partially but not solely related to a thrombotic complication. It's treatment remains unclear in the absence of related oriented studies.The current mechanical and pharmacological antithrombotic therapies must remain common practice and used appropriately as of the clinical and angiographic setting, until further scientific outbrakes.

Efficacy and safety of local intracoronary drug delivery in the distal coronary bed as treatment of no-reflow phenomenon during percutaneous coronary intervention

Abstract Background No-reflow is a complication of percutaneous coronary interventions (PCI), which occurs in 0.6–5% of elective PCIs, but it may be observed in up to 50% of primary PCI cases, involving the treatment of thrombus-containing lesions. An optimal standard treatment of no-reflow (NR) has not yet been established. Intracoronary (IC) vasodilators are being administered for the treatment of NR via the guiding catheter, but sometimes distal flow restoration is not satisfactory especially in patients with TIMI 0 flow. Purpose To investigate the efficacy and safety of local IC drug delivery in the distal coronary bed via a microcatheter as a treatment option of NR phenomenon during PCI. Methods A retrospective analysis of 4606 PCI procedures done in our institution was conducted, to identify patients who suffered from NR during PCI (TIMI 0-I flow in the absence of mechanical obstruction). In patients with NR, local IC infusion of vasodilators (Nitroprusside 50–200 mcg, Adenosine 30–40 mcg) was infused, via a microcatheter or thrombus-aspiration catheter, distal to the angioplasty site. Repeated injections were done with both drugs at the operator's discretion, until best flow was achieved, but without exceeding the maximum recommended dose. If the patient was hypotensive and, thus, the administration of IC vasodilators for treating slow flow/NR was impeded, 100–200 mcg IV phenylephrine were administered, to increase blood pressure. Afterwards, IC vasodilators were infused. Results In 4606 conducted PCIs, 83 patients suffered from NR (1.8%). The age of patients with NR was 65.17±11.69 years. As for the sex, there were 10 female (12.1%) and 73 male (87.9%) patients. The mode of presentation was: 1) STEMI in 28 patients (33.7%), 2) NSTEMI-Unstable Angina in 21 patients (25.3%) and 3) stable angina in 34 patients (41%). NR was observed in 57 patients (68.7%) at post-stenting and in 26 patients (31,3%) at post-dilation. The affected vessel was LAD in 35 patients (42.2%), LCx artery in 16 patients (19.3%), RCA in 28 patients (33.7%) and SVG in 4 patients (4.8%). The IC-infused drug was adenosine in 21 patients and nitroprusside in 62 patients. The total number of infusions was 4.05±1.88. TIMI III flow was achieved in 90.3% of patients and MBG II/III was achieved in 89.1%. The combination of TIMI III flow with MBG II/III was achieved in 87.9% of the patients. In the subgroup of patients with STEMI, the combination of TIMI III flow with MBG II/III was achieved in 85,7% of the patients. As for the complications, a transient systolic pressure drop below 90 mmHg occurred in 4 patients, while there was one death, due to cardiogenic shock complicating acute anterior MI. Conclusion Local IC delivery of vasodilator drugs in the distal coronary bed via microcatheter during PCI is a safe and effective treatment of NR phenomenon, and it can enhance the myocardial perfusion, in addition to reducing infarct's size. Also, it may improve the post-PCI prognosis. Funding Acknowledgement Type of funding sources: None.

Neurocognitive improvement after angioplasty in patients with chronic middle cerebral artery stenosis and cerebral ischemia.

The use of middle cerebral artery (MCA) angioplasty compared with drug therapy has been controversial. Few studies have reported the correlations between cognitive function improvement and MCA angioplasty. This study aimed to explore neurocognitive function after angioplasty in patients with middle cerebral artery stenosis (MCAS) and objective cerebral ischemia. We identified 14 patients diagnosed with MCAS aged 45-65 years. Neurocognitive function evaluation was performed by 2 independent clinical psychologists using the Mini-Mental State Examination (MMSE), Montreal cognitive assessment scale (MoCA), and Multi-Dimensional Psychology. All patients received general anesthesia, underwent diagnostic cerebral angiography (DSA) via the femoral route and angioplasty, and then were sent to the neurologic intensive care unit (NICU) for overnight hemodynamic and neurologic monitoring. Aspirin and clopidogrel treatments were continued for 3 months after successful intervention. Complete neurologic examinations, including assessment with the National Institutes of Health Stroke (NIHSS), and modulate RANK score (MRS) were conducted by 2 independent neurologists. The patients received a family follow-up at 1 week, 1 month, and 3 months after the interventional procedure. Neurologic sequelae, intracranial hemorrhages, and deaths were recorded as an endpoint. Follow-up clinical and imageological examinations were scheduled at 6 months after the intervention. Follow-up brain computed tomography (CT) perfusion or magnetic resonance angiography (MRA) perfusion scans performed by 2 imageological scanners were scheduled 6 months after the procedure. Angioplasty technical success was achieved in 14 parents (100%). We found that 10 patients did not have recurrent MCAS in the angioplasty site and had significant improvements in the associated brain perfusion situation and cognitive founction as compared before and after angioplasty. Also, 4 patients had evident restenosis in the angioplasty site. In the nonstenosis group, we found significant improvements in the MMSE, 3-dimensional (3D) mental rotation, simple calculation, and spatial working memory. In the recurrent stenosis group, we found no statistically significant changes in cognitive function compared with the baseline and after a 6-month follow up. There were high correlations between the changes in perfusion and the changes in word and picture memory. There was a significant correlation between the change in perfusion with MMSE (-0.522), spatial working memory (0.655), and Raven's progressive matrices test (0.637); a moderate correlation with 3D rotation (0.413), and simple calculation (-0.359); and weak correlation with visual tracking (0.026) and MoCA (0.279). Angioplasty surgery significantly improves neurocognitive function in patients with middle cerebral artery stenosis (MCAS) and objective cerebral ischemia.

Fatigue of textiles used in vascular surgery: Application to carotid endarterectomy

Fatigue is a material-based phenomenon playing a significant role in the mechanical behavior of components and structures. Although fatigue has been well studied for traditional materials, such as metals, its underlying mechanisms are not thoroughly understood in novel applications such as the case of textiles used as patches to close the arteriotomy in carotid endarterectomy. The latter is a type of vascular surgery for the treatment of carotid artery disease in which after an arteriotomy and removal of atherosclerotic plaque closure is made with a patch sutured on the artery. Completion of the operation signals the initiation of complex mechanical and hemodynamic phenomena. Fatigue performance of the patch eventually determines the successful outcome of carotid endarterectomy. In this study, we evaluate with a two-fold approach the mechanics of patch angioplasty in carotid endarterectomy. First, an analytical model for the fatigue behavior of textiles is developed, considering the microstructure and geometry of the fabric. Then, the surgical procedure is simulated and a finite element analysis of the endarterectomized and patched carotid artery is employed. Stress fields are calculated, while deformation at the site of patch angioplasty indicates a potential cause for the formation of aneurismal degeneration after the surgery. Such analysis can provide a better understanding in the establishment of follow-up protocols.

Predicting Amputation using Local Circulating Mononuclear Progenitor Cells in Angioplasty-treated Patients with Critical Limb Ischemia.

Critical limb ischemia (CLI) represents an advanced stage of the peripheral arterial disease. Angioplasty improves the blood flow to the lower limb; however, some patients irreversibly progress to limb amputation. The extent of vascular damage and the mechanisms of vascular repair are factors affecting post-angioplasty outcome. Mononuclear Progenitor Cells (MPCs) are reactive to vascular damage and repair, with the ability to reflect vascular diseases. The present protocol describes quantification of MPCs obtained from blood circulation from vessel close to the angioplasty site, as well as its relationship with endothelial dysfunction and its predictive ability for limb amputation in the next 30 days after angioplasty in patients with CLI.

Circulating miRNA-23b and miRNA-143 Are Potential Biomarkers for In-Stent Restenosis.

In-stent restenosis (ISR) is one of the main complications in patients undergoing percutaneous coronary angioplasty, and microRNAs participate in the contractile-to-synthetic phenotypic switch of vascular smooth muscle cells, a hallmark of restenosis development. MicroRNAs (miRNAs) can be released into circulation from injured tissues, enticing a potential role as noninvasive biomarkers. We aimed to evaluate circulating levels of miRNA-23b, miRNA-143, and miRNA-145 as diagnostic markers of ISR. 142 patients with coronary artery disease undergoing successful angioplasty and a follow-up angiography were included. Subjects were classified according to the degree of obstruction at the angioplasty site into cases (≥50%) or controls (<50%). Total RNA was isolated from plasma to quantify circulating miRNAs levels, and the ROC curves were constructed. Among circulating miRNAs assessed, miRNA-23b and miRNA-143 were significantly lower in cases (miRNA-23b: 18.4x10−5 and miRNA-143: 13.7x10−5) than controls (miRNA-23b: 5.2x10−5, p < 0.0001; miRNA-143: 4.0x10−5, p < 0.0001). Plasma levels of miRNA-145 showed no significant differences. The analysis of the ROC curves showed an area under the curve for miRNA-23b of 0.71 (95% CI: 0.62-0.80, p < 0.0001) and 0.69 for miRNA-143 (95% CI: 0.60-0.78; p < 0.0001). Our data suggest that plasma levels of miRNA-23b and miRNA-143 could be useful as noninvasive biomarkers of ISR.

Genetic predisposition for the development of complications in patients after coronary artery stenting

In the review the authors analyzed the literature data on the state of knowledge of the problems of genetic polymorphisms CYP2C19 gene response to clopidogrel in patients with acute coronary syndrome. Despite on the technological advances and the widespread use of coronary stenting, restenosis at the site of angioplasty remains the main factor limiting its long-term effectiveness. We made the literature review of the state of the study of the genetic polymorphism of the CYP2C19 gene for a response to clopidogrel in patients with acute coronary syndrome and percutaneous coronary intervention. To achieve this goal, a systematic search and subsequent analysis of publications and online resources were carried out. All publications are indexed in the PubMed, Medline, e-Library, CoogleScholar.

Transfemoral Venous Access Facilitates Upper Extremity Dialysis Interventions: Procedural Success and Clinical Outcomes.

To report technical success and clinical outcomes of transfemoral venous access for upper extremity dialysis interventions. A total of 15 patients underwent a transfemoral venous approach for fistulography (n = 4; 27%) or thrombectomy (n = 11; 73%) over a 14-month period. Access characteristics, sheath size, thrombectomy method, angioplasty site, fluoroscopy time, radiation dose, technical and clinical success, complications, and post-intervention primary and secondary patency rates were recorded. Access type included arteriovenous fistulas (n = 10; 67%) and grafts (n = 5; 33%). The most common configuration was brachio-brachial (n = 6; 38%). Mean age of access was 37months. Mean prior interventions were 4. Right CFV access was used in all patients using 6-8-French (most common: 7-French [n = 10; 67%]) sheaths. Most thrombectomies (n = 11; 73%) required both pharmacologic and mechanical maceration (n = 9; 82%). All accesses required angioplasty to treat underlying stenosis at the outflow vein (n = 12; 80%) or arteriovenous anastomosis (n = 9; 90%). Mean fluoroscopy time was 26.43min. Air kerma and dose area product were 178.06 ± 225.77mGy and 57,768.83 ± 87,553.29μGym2, respectively. Procedural and clinical success rates were 93% and 80%, respectively. Technical failure was due to persistent stenosis in one patient. Clinical failure was due to unsuccessful dialysis immediately following intervention in three patients. Mean post-intervention primary patency and secondary patency durations were 2.8 and 4.8months, respectively. Primary patency rates at 1 and 3 months were 50% and 35%, respectively. Secondary patency rates at 1 and 3 months were 58% and 30%, respectively. A transfemoral venous approach for intervention of upper extremity dialysis accesses may be a valuable adjunct to traditional approaches.

Subsets of CD8+ T lymphocyte – Early reactants in post-angioplasty injury of arteries in patients with peripheral arterial occlusive disease

Aim: Early recruitment of T lymphocytes at the vascular injury site is known as initiating phenomenon in atherosclerotic plaque development. Immunosenescent CD28null CD8+ T cells are attributed to the plaque destabilization in animal models and in vitro experimentation. T lymphocytes behavior in Peripheral Arterial Disease (PAD) is mostly unknown. We hypothesized, that acute changes in T cells at a percutaneous transluminal angioplasty (PTA) site, can serve an index of their potential interaction with injured vascular wall.

Involvement of CD8+ T cell subsets in early response to vascular injury in patients with peripheral artery disease in vivo

AimsAdaptive immunity is critical in vascular remodelling following arterial injury. We hypothesized that acute changes in T cells at a percutaneous transluminal angioplasty (PTA) site could serve as an index of their potential interaction with the injured vascular wall. Methods and ResultsT cell subsets were characterised in 45 patients with Rutherford 3–4 peripheral artery disease (PAD) undergoing PTA. Direct angioplasty catheter blood sampling was performed before and immediately after the procedure. PTA was associated with an acute reduction of α/β-TcR CD8+ T cells. Further characterisation revealed significant reduction in pro-atherosclerotic CD28nullCD57+ T cells, effector (CD45RA+CCR7-) and effector memory (CD45RA-CCR7-) cells, in addition to cells bearing activation (CD69, CD38) and tissue homing/adhesion markers (CD38, CCR5). ConclusionsThe acute reduction observed here is likely due to the adhesion of cells to the injured vascular wall, suggesting that immunosenescent, activated effector CD8+ cells have a role in the early vascular injury immune response following PTA in PAD patients.

Predictors of angiographically visible distal embolization in STEMI.

Distal embolization during primary percutaneous coronary intervention (p-PCI) in the treatment of ST-segment elevation myocardial infarction (STEMI) is associated with apoor prognosis. In this situation, thrombectomy is performed to prevent distal embolization and to restore myocardial reperfusion. The aim of our study was to determine angiographic predictors of angiographically visible distal embolization (AVDE) in patients with STEMI treated by p‑PCI with thrombectomy. This prospective study included all consecutive patients who underwent p‑PCI with thrombectomy for STEMI at our institution between October 2011 and December 2014 AVDE was defined as adistal filling defect with an abrupt cut-off in one of the peripheral coronary branches of the infarct-related artery, distal to the angioplasty site. Thrombectomy was considered positive when it removed thrombi, and successful when it improved coronary flow. Among the 346 patients included, 59 (17%) developed AVDE during p‑PCI. In multivariate analysis, the infarct-related right coronary artery (OR: 2.48, 95% CI: 1.36-4.52; p = 0.003) and aculprit lesion diameter of >3 mm (OR : 1.90, 95% CI: 1.01-3.56; p = 0.048) were identified as independent factors associated with AVDE during p‑PCI with thrombectomy for STEMI. The success of thrombectomy and the Syntax score were not associated with AVDE. AVDE complicating p‑PCI with thrombectomy in STEMI is frequent (17%) and asuccessful thrombectomy does not rule out AVDE.

CYP2C19⁎2 Polymorphism in Chilean Patients with In-Stent Restenosis Development and Controls.

Clopidogrel is an antiplatelet drug especially used in patients undergoing percutaneous coronary interventions (PCI). Polymorphisms within CYP2C19 can result in important interindividual variations regarding therapeutic efficacy. Therefore, we aimed to evaluate the impact of the CYP2C19⁎2 variant (rs4244285) on in-stent restenosis occurrence in Chilean patients who underwent PCI and received clopidogrel. A total of 77 cases with stenosis >50% in the angioplasty site (62.75 ± 9.8 years, 80.5% males) and 86 controls (65.45 ± 9.8 years, 72.1% males) were studied. The polymorphism was genotyped using TaqMan® Drug Metabolism Genotyping Assays. Overall, CYP2C19⁎2 allele frequency was 8.3%. Diabetes, chronic lesions, and bare metal stents (BMS) were observed more often in cases than in controls (p = 0.05, p = 0.04, and p = 0.02, resp.). Genotypic frequencies did not differ significantly between the groups (p = 0.15). Nonetheless, the mutated allele was observed in a greater proportion in patients without in-stent restenosis (p = 0.055). There was no significant association between the rs4244285 variant and the occurrence of in-stent restenosis after PCI (OR = 0.44; 95% CI: 0.19 to 1.04; p = 0.06). In summary, no association was identified between the CYP2C19⁎2 variant and the development of coronary in-stent restenosis.

Static and Flow Conditions: Endothelial Cell Migration onto Metal Stent Surfaces.

Restenosis associated with intimal hyperplasia and thrombosis at sites of balloon angioplasty or stent placement remains an important clinical problem. It is likely that loss or damage to the arterial endothelium associated with these interventional procedures as well as the rate of its restoration plays a critical role in the extent of restenosis. Migration of arterial endothelial cells from adjacent intact endothelium is the predominant source of cells involved in re-endothelialization of the injured site. In this paper, we review the influence of hemodynamics on endothelial cell migration, both in vivo and in vitro. In addition, we present recent in vitro studies demonstrating the importance of the nature of metal substrates in modulating endothelial cell migration rate. Finally, we review the cellular and molecular mechanisms likely involved in governing endothelial cell migration, and relate them to a possible scenario of endothelial response to injury at sites of arterial intervention. Understanding the important factors regulating endothelial migration may provide insights that will ultimately lead to methods to accelerate endothelial healing and reduce the occurrence of arterial restenosis.

5-Fr sheathless transradial cardiac catheterization using conventional catheters and balloon assisted tracking; a new approach to downsizing.

While the uptake of transradial access site is growing, there are concerns about associated radial injury. We report a feasibility study of a technique that enables both 5Fr diagnostic and PCI cases to be undertaken without an arterial sheath using conventional diagnostic and guide catheters with a modified balloon assisted tracking (BAT) technique. We performed a prospective single center pilot study to assess the feasibility and effectiveness of sheathless radial artery access and BAT to perform coronary angiography and angioplasty using conventional 5 Fr diagnostic and guide catheters. We assessed for successful acquisition of good quality angiogram, completion of the angioplasty and access site complications. 5 Fr sheathless cardiac catheterization was undertaken in diagnostic (55%) and PCI cases (45%, all indications) in 60 consecutive patients (mean age 62.8±11.4years) using conventional catheters. The procedure was successfully performed via the radial artery using a sheathless technique with BAT in 93.3% of patients. All patients had a patent radial artery following removal of the Helix device and there were no recorded access site complications. Trans-radial cardiac catheterisation for diagnostic and PCI cases using 5F Sheathless catheters (whose outer diameter is smaller than a 3Fr introducer sheath) with BAT appears feasible and allows both cardiac catheterization for diagnostic and PCI indications to be undertaken safely using conventional catheters through the radial route, with high success rates.

Large hematoma over the puncture site of percutaneous transluminal coronary angioplasty as a presenting sign of severe dengue infection

Dengue fever is a common arboviral infection all over the world. It is endemic in the tropical and subtropical areas of the world with periodic epidemics in these areas. In its severe form dengue patients may develop life-threatening bleeding manifestations. We report here a case of large hematoma formation precisely located over the puncture site of percutaneous transluminal coronary angioplasty as a presenting sign of severe dengue infection for its unusual occurrence.<Learning objective: Severe dengue including dengue shock syndrome is a potentially life-threatening condition. Dengue virus-induced coagulopathy and thrombocytopenia may further complicate cardiological interventions like percutaneous transluminal coronary angioplasty or coronary artery bypass grafting as such patients are already on antiplatelet drugs. Performing any cardiovascular intervention in an endemic area of dengue needs proper vigilance to avoid such potentially life-threatening complications.>

Cross-Leg Flap-Sharing Technique Using an Anterolateral Thigh Perforator Flap.

Cross-Leg Flap-Sharing Technique Using an Anterolateral Thigh Perforator Flap.