Vascular Devices Research Articles

Endograft Device type is a Significant Risk Factor for Limb Graft Occlusion After Endovascular Aortic Repair of Infrarenal Abdominal Aortic Aneurysm

Introduction: Limb graft occlusion (LGO) is an uncommon yet serious complication after EndoVascular Aortic Repair (EVAR). It is reportedly influenced by several patient-specific anatomical variables. In a rapidly developing field of new vascular devices and an overall tendency toward endovascular treatment of complex aortic cases, minimising complications becomes increasingly important. Albeit worldwide clinical usage, there is still a lack of long-term follow-up data for many “second generation” endograft types. Our objective was to identify factors associated with LGO after EVAR. Methods: Between 2013-2018, all patients undergoing standard EVAR for infrarenal aortic aneurysms at two high-volume Vascular referral centers were included in this study. Cases treated with fenestrated or branched endografts were excluded. Patients were identified through a national registry for Vascular Surgery and all pertinent data was retrospectively collected from patient electronic medical records. LGO was defined as a symptomatic total limb occlusion requiring intervention. Results: Mean age at primary intervention for the 639 patients included was 75.3 years and 85.5% were men. Three graft manufacturers were predominantly used; Medtronic Endurant (n=274), Cook Zenith (n=243) and Gore Excluder (n=122). All grafts were bifurcated and the majority were deployed in an elective setting (77.5%). Median follow-up time for respective groups was 52, 21 and 25 months. A total of 29 patients presented with LGO (4.5%); 8 patients treated with Medtronic (2.9%), 19 with Cook (7.8%) and 2 with Gore (1.6%). Cox proportional hazard regression models were used to estimate multivariable hazard ratios (HR) with 95% confidence intervals (95% CI) of LGO during follow up. The multivariable HR of LGO was increased more than 6-fold in the Cook Zenith group, compared with Medtronic Endurant (HR, 6.14; 95% CI, 2.29 - 16.44), and Gore (HR 7.10; 95% CI, 1.55 - 32.57) respectively. There was no significant difference in rate of LGO when comparing Gore with Medtronic (HR, 0.87; 95% CI, 0.18-4.26). The observed point estimates in univariable models did not differ from those observed after adjustment for potential confounders in multivariable models. We observed no difference in rate of all cause mortality between the three groups. Conclusion: In this study, endograft device type was identified as an independent risk factor for LGO after EVAR. Specifically, limbs in the Cook Zenith endografts were observed to occlude at a 6 times higher rate compared with the Medtronic Endurant or Gore Excluder devices. [Rate of Limb Graft Occlusion] Disclosure: Nothing to disclose

Patient Harm from Repetitive Blood Draws and Blood Waste in the ICU: A Retrospective Cohort Study

Introduction: Frequent blood testing in the intensive care unit (ICU) is instrumental to patient diagnosis, monitoring, and titration of invasive therapies. However, there is a growing appreciation that a significant proportion of ICU blood tests are reflexive and unnecessary.1,2 Serial phlebotomy is associated with extended hospital length of stay and acquired anemia in the general hospital population.3 Since patients in the ICU are prone to developing anemia,4,5 they are likely at increased risk of harm from serial phlebotomy. In response, multiple recent campaigns advocate for physician restraint in laboratory test ordering.6,7 However, relatively little is known about the effect of excessive phlebotomy on outcomes in critically ill patients. Better understanding of ICU phlebotomy practices, and harms associated with serial testing, is important in planning, implementing, and evaluating phlebotomy reduction interventions. Objectives: 1) Quantify average daily phlebotomy volume for ICU patients including blood discarded as waste when accessing vascular devices. 2) Identify if average daily phlebotomy volume is an independent risk factor for ICU acquired anemia (hemoglobin < 80 g/L) or the need for red blood cell transfusion. 3) Explore the relationship between daily phlebotomy volume and hospital mortality. Methods: This was a retrospective cohort study at an academic tertiary care center in Toronto, Ontario, utilizing hospital administrative data, laboratory data, and select chart review. Index Medical Surgical ICU admissions between September 2014 and August 2015 with an ICU stay of three days or greater were included. Major bleeding events were defined as a hemoglobin drop of 30 g/L within a 24 hour period. Average daily phlebotomy volumes were calculated using the number of samples received by the lab multiplied by standard blood volumes required for each sample type. A bedside prospective audit was conducted in March 2018 to quantify average blood volume discarded as waste during phlebotomy. Blood discard/waste data were summarized with descriptive statistics, but not included in further analysis. Multivariable logistic regression was used to study the association between average daily phlebotomy volume and each of: nadir hemoglobin (< 80 g/L), the need for red blood cell transfusion, and hospital mortality. Patients with a major bleeding event were excluded from the regression. Control variables included sex, age, ICU length of stay, admission hemoglobin, and admission Sequential Organ Failure Assessment (SOFA) score. Results: There were a total of 525 index patient admissions, mean age 62.1 yr, 41% female (Table 1). Fifty-two (52) patients had a major bleeding event in the ICU. Mean phlebotomy volume per patient day was 28.3 mL (95% CI 27.4 - 29.1 mL, stdev 10.1 mL). Mean bedside waste during the phlebotomy audit (total of 144 blood draws) varied by vascular access: 3.9 mL for arterial, 5.5 mL for central venous, and 6.25 mL for peripherally inserted catheters. The mean estimated daily bedside waste for phlebotomy was 14.8 mL per patient day. Outcomes of logistical regression, excluding patients with major bleeding events, are summarized in Table 2. Average daily phlebotomy volume (mL) was predictive of nadir hemoglobin < 80 g/L (parameter estimate 0.091, p <0.001), the need for red blood cell transfusion (0.092, p<0.001), and inpatient mortality (0.053, <0.001). For every 5 mL increase in average daily phlebotomy, the odds ratio (OR) for nadir hemoglobin < 80 g/L was 1.58 (95% CI 1.31 - 1.90) and the OR for a red cell transfusion was 1.58 (95% CI 1.33 - 1.87). Conclusion: Daily ICU phlebotomy volume is associated with ICU acquired anemia and the need for red blood cell transfusion, including in a multivariable model with patient demographics, major bleeding events, and severity of illness as estimated by day 1 SOFA score. However, the ICU admission SOFA score was only weakly predictive of mortality, and the unexpected association between average daily phlebotomy and mortality needs to be further explored. It is possible that in this data set day 1 SOFA score did not completely control for severity of illness. Our findings support the need for ongoing phlebotomy stewardship interventions in the ICU. We suggest ICU acquired anemia and the need for red blood cell transfusion are appropriate patient outcome measures to evaluate stewardship interventions. Disclosures No relevant conflicts of interest to declare.

Incidence, Characteristics and Management of Persistent Peri-Device Flow after Percutaneous Left Atrial Appendage Occlusion

ABSTRACT Background : Severe peri-device leaks after left atrial appendage (LAA) occlusion requires continuation of life-long oral anticoagulation. However, the majority of patients referred for LAA occlusion are not suitable for anticoagulation. Data on the incidence, characteristics, and management of peri-device leak after LAA occlusion are scarce. Methods : We assessed the incidence of peri-device leak, its characteristics, and their management outcomes in 200 consecutive patients who underwent LAA occlusion between April 2016 and August 2018. Results : Severe persistent peri-device flow was present in 9/200 patients (4.5%) at 45 days. Baseline clinical characteristics were comparable between patients with or without severe leaks. However, patients with severe leaks had larger LAA diameter (24.5 ± 4.3 vs. 19.8 ± 3.7 mm, p < 0.001), and more sub-optimal deployments (100% vs. 26.7%, p < 0.001). Sub-optimal deployment parameters included: non-coaxial deployment, preferential single lobe deployment, incomplete coverage of a proximal side lobe, and shallow implantation. Among patients with severe leaks, 7 (78%) underwent percutaneous closure. Percutaneous closure with the Amplatzer Vascular Plug-II device had a 100% success rate and no short-term complications. Conclusions : Severe peri-device leak is present in ~5% of patients following LAA occlusion. Certain anatomical and procedural factors might contribute to the occurrence of peri-device leak. Severe leaks can be effectively closed with percutaneous techniques.

PICC-PORT totally implantable vascular access device in breast cancer patients undergoing chemotherapy.

The increasing use of arm totally implantable vascular access devices for breast cancer patients who require chemotherapy has led to a greater risk of complications and failures and, in particular, to upper extremity deep vein thrombosis. This study aims to investigate the outcomes of the arm peripherally inserted central catheter-PORT technique in breast cancer patients. The peripherally inserted central catheter-PORT technique is an evolution of the standard arm-totally implantable vascular access device implant based on guided ultrasound venous access in the proximal third of the upper limb with subsequent placement of the reservoir at the middle third of the arm. A prospective study was conducted on 418 adult female breast cancer patients undergoing chemotherapy. The primary study outcome was peripherally inserted central catheter-PORT failure. Median follow-up was 215 days. Complications occurred in 29 patients (6.9%) and failure resulting in removal of the device in 11 patients (2.6%). The main complication we observed was upper extremity deep vein thrombosis, 10 (2.4%); all patients were rescued by anticoagulant treatment without peripherally inserted central catheter-PORT removal. The main reason for removal was reservoir pocket infection: 4 (0.9%) with an infection rate of 0.012 per 1000 catheter days. Cumulative 1-year risk of failure was 3.6% (95% confidence interval, 1.3%-7.1%). With regard to the patients' characteristics, body mass index <22.5 was the only significant risk for failure (p = 0.027). The peripherally inserted central catheter-PORT is a safe vascular device for chemotherapy delivery that achieves similar clinical results as traditional long-term vascular access devices (peripherally inserted central catheter and arm totally implantable vascular access device, in particular) in breast cancer patients.

Mini-midline in difficult intravenous access patients in emergency department: A prospective analysis.

"Difficult intravenous access" patients represent a challenge within an emergency department as they often require many attempts to insert a peripheral short cannula in the emergency room or during the whole hospitalization. This can lead to many problems in terms of patient discomfort, increase of cost, and prolonged treatment time. This study aimed to reduce the number of attempts needed for a short-cannula insertion or preventing insertion of a central vascular access by placing an ultrasound-guided long cannula during the emergency department visit. The insertion of mini-midline was monitored within an emergency room in 50 patients considered difficult intravenous access patients, who failed two attempts at peripheral venous access insertion and/or required the use of an alternative vascular device. A total of 46 patients out of 50 were monitored. In 38 (82%) patients, the device was removed due to the end of the indication, and in six of them, it was replaced by a central venous catheter. Two devices were left inside even after discharge and were then removed at the end of indication. In eight (17%) patients, the device was removed due to accidental removal (4) and malfunction (4). In all the cases, the average duration of the insertion procedure was 10 min. The mean dwell time accounted to 7 and 9 days. The insertion of a mini-midline as part of the first emergency room visit in selected patients is a rapid, safe, and cost-effective procedure, which can provide the patient with stable venous access during the all hospitalization time.

1776P - High incidence of venous thromboembolic events (VTE) in patients with diffuse large b-cell lymphoma

BackgroundIncidence of venous thromboembolic events (VTE) is higher among cancer patients, especially while on chemotherapy. Diffuse large B-cell lymphoma (DLBL) is the most common lymphoma. Studies that specifically evaluated the risk of VTE in patients with different kinds of lymphomas reported a risk ranged from 1.5% to 14.6%. In this study, we specifically address VTE in a unified lymphoma population. MethodsMedical records and hospital databases were searched for patients with a diagnosis of DLBL and VTE. All patients were diagnosed, treated and followed up at our institution. The Khorana and “Throly” risk assessment models (RAM) were applied on all patients and known risk factors for VTE were studied. ResultsA total of 393 patients (52.4% males), median age: 49 (range: 18-90) years were included. At diagnosis, 163 (41.5%) were stage IV, 116 (29.5%) had bulky disease and 197 (50.1%) had high LDH. All patients were treated on a unified guidelines using R-CHOP chemotherapy; 285 (72.5%) achieved CR while 72 (18.3) had salvage chemotherapy. Venous thromboembolic events were reported in 57 (14.5%) patients. Pulmonary embolism (PE) with or without deep venous thrombosis (DVT) was reported in 24 (42.1%), 8 of them (33.3%) were incidental. Upper extremity DVT were seen in 18 (31.6%); only 4 (22.2%) were associated with a vascular device. Thrombosis was diagnosed in ambulatory sitting in 30 (52.6%) and majority of the VTE occurred while on active chemotherapy; 20 (35.1%) while on initial induction and 15 (26.3%) while on salvage chemotherapy, however, 19 (33.3%) occurred before the initiation of any chemotherapy. Among the 35 patients on active chemotherapy, only 6 (17.1%) had high Khorana risk score. In a multivariate analysis, significantly higher rates of thrombosis were associated with stage-IV disease, high LDH and high International Prognostic Index (IPI). Sex, age, BMI, and the Khorana risk score were not. ConclusionsIncidence of VTE in patients with DLBL is high and majority of such events occurred in ambulatory setting were VTE prophylaxis is not offered. Upper extremity DVT and incidental PE were exceptionally high. Stage at diagnosis, IPI score and LDH are important in predicting the risk for thrombosis. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Covalent immobilization of biomolecules on stent materials through mussel adhesive protein coating to form biofunctional films.

It is widely accepted that surface biofunctional modification may be an effective approach to improve biocompatibility and confer new bioactive properties on biomaterials. In this work, mussel adhesive protein (MAP) was applied as a coating on 316 L stainless steel substrates (316 L SS) and stents, and then either immobilized VEGF or CD34 antibody were added to create biofunctional films. The properties of the MAP coating were characterized by scanning electron microscope (SEM), atomic force microscope (AFM) and a water contact angle test. Universal tensile testing showed that the MAP coating has adequate adhesion strength on a 316 L stainless steel material surface. Subsequent cytotoxicity and hemolysis rate tests showed that the MAP coatings have good biocompatibility. Moreover, using N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysulfosussinimide (EDC/NHS) chemistry, VEGF and CD34 antibody were immobilized on the MAP coatings. The amount and immobilized yield of VEGF on the MAP coatings were analyzed by enzyme-linked immuno-assays (ELISA). Finally, an endothelial cells culture showed that the VEGF biofunctional film can promote the viability and proliferation of endothelial cells. An in vitro CD34+ cells capturing test also verified the bioactive properties of the CD34 antibody coated stents. These results showed that the MAP coatings allowed effective biomolecule immobilization, providing a promising platform for vascular device modification.

Leukocytapheresis in nonmobilized donors for cellular therapy protocols: Evaluation of factors affecting collection efficiency of cells

Collection efficiency (CE1) of cells refers to the number of cells that are collected from the total number of cells processed by the apheresis device. Limited data are available about the CE1 of cells when performing leukocytapheresis in nonmobilized donors for cellular therapy purposes. The aim of our study was to evaluate donor- and procedure-related characteristics that might influence the CE1 of cells. Variables that predicted the CE1 of cells were analyzed by longitudinal linear regression in a series of 1071 leukocytapheresis procedures on 249 nonmobilized donors. Donor-related characteristics considered were gender, age, total blood volume, and complete blood count (CBC) data. Procedure-related characteristics considered were vascular access and device used. Older donor age was associated with a decrease in the CE1 of leukocytes, lymphocytes, monocytes, and mononuclear cells (MNCs; sum of leukocytes and monocytes) and with an increase in the CE1 of platelets (P < .05). Preprocedure CBC data (leukocytes, lymphocytes, monocytes, and platelets) were associated with either a statistically significant increase or decrease in the CE1 of cells. Central line used as vascular access was associated with a statistically significant decrease in the CE1 of MNCs (P = .02). Donor's age, preprocedure CBC data as well as central line used as vascular access were factors associated with CE1 of cells. Knowing these characteristics is helpful in the apheresis unit when designing cellular therapy protocols in order to maximize the CE1 of the desired cell and to personalize collection variables for each donor.

Implementation and 2‐year outcomes of the first FDA‐approved implantable apheresis vascular access device

Patients requiring chronic apheresis treatments typically lack sufficient peripheral venous access to support long-term therapy. Historically, central venous tunneled catheters, septum-bearing subcutaneous ports, and fistulas were used to obtain required blood flow rates for apheresis procedures. In 2017, the US Food and Drug Administration approved the first intravascular device specifically designed for apheresis therapy, the PowerFlow Implantable Apheresis IV Port. Several preimplementation meetings with key hospital stakeholders were held to determine the most efficient and safest strategy for integrating the PowerFlow device into our practice. Interventional radiologists implanted the apheresis port in patients meeting specified criteria. Performance metrics and adverse events were evaluated over a 2-year period, July 2017 through June 2019. Eighteen patients underwent apheresis therapy using the PowerFlow port. The most common apheresis therapy provided was extracorporeal photopheresis, followed by therapeutic plasma exchange and low-density lipoprotein apheresis. Flow rates up to 90 mL/min were obtained; the rates were limited by patient tolerance for the apheresis procedure. Complications included infection, obstruction due to fibroblastic sleeve, and migration of the vascular device. The estimated risk of PowerFlow-associated bloodstream infection in the study population was 0.18 per 1000 intravascular device days. The PowerFlow Implantable Apheresis IV Port can achieve flow rates necessary for all apheresis therapies and is a promising alternative vascular access device for patients undergoing apheresis.

Enjeux émergents liés aux accès vasculaires, quelle stratégie face à l’évolution du profil des patients hospitalisés ?

Peripheral venous catheters are the most commonly used vascular devices in hospitals. The ageing population and the increase in comorbidities makes their insertion more complex. A survey carried out in surgical units describes the factors contributing to failures. It is importantto improve the identification of patients with difficult venous access, to offer access to various techniques anddevices, as well as to the expertise of a specialised team.

Initial experience with vascular plug devices for mechanical thrombectomy in symptomatic neonates and infants.

To describe a novel technique for mechanical thrombectomy (MT) in young children. Acute thrombosis in children may be a cause of significant morbidity or mortality. MT options in children are limited due to patient and vessel size, prompting consideration of innovative approaches. Two-center review of children with symptomatic non-cerebral thrombotic vessel occlusion. A novel approach to MT was performed using a deployed but unreleased amplatzer vascular plug (AVP) to "scrape" the target vessel in retrograde fashion, thereby harvesting the thrombus via the access sheath. AVP-MT was performed in four patients at a median age of 2 months (range: 1 day-11 months) and median weight of 5.6 kg (1.8-10.9). In two cases, AVP-MT was performed in isolation in neonates on cervical extracorporeal membrane oxygenation (ECMO) support with cannula-associated obstructive aortic and brachiocephalic thrombus. AVP-MT was also performed as adjunctive therapy in a patient with single ventricle physiology and pulmonary artery thrombosis and in an infant with mitral valve endocarditis and femoral arterial thromboembolism. In all cases, AVP-MT was used to successfully remove thrombus from the target vessel and restore arterial flow, without procedural complications. Recurrent thrombosis occurred in both neonates, due to persistence of the ECMO cannula, with subsequent mortality. The other children were free of recurrent thrombus at 2 and 34 months. Acute relief of symptomatic thrombosis may be achieved using AVP-MT in small children, although thrombosis frequently recurs, and clinical prognosis may remain poor. This strategy should be considered when alternative MT treatment options are not applicable.

Invasive candidiasis trial supports echinocandins for primary therapy

Candida , the most prevalent hospital-associated fungal pathogen, causes a variety of mucosal and deep-seated infections (1). Candidemia and other invasive Candida infections are among the more difficult to treat infections and are associated with high mortality rates, near 40% (2). Neutropenia, often related to chemotherapy or hematologic malignancy, places patients at high risk for severe disseminated candidiasis (3). The current recommended therapy involves a combination of treatment with antifungals, debridement and/or drainage of intra-abdominal sources, and removal of infected devices, such as vascular catheters and implantable cardiac devices (2,4-7).

Listeria monocytogenes-associated endovascular infections: A study of 71 consecutive cases

Listeria monocytogenes-associated endovascular infections are not well characterized. Retrospective study of 71 culture-proven cases reported to the French National Reference Center for Listeria from 1993 to 2018. Seventy-one cases were identified: 42 with vascular aneurysms/prosthetic infections, 27 with endocarditis, 2 with both. Fifty-eight were men (82%); median age was 75 years [46-92]; 93% reported co-morbidities (66/71), including 50% with immunosuppressive conditions. Vascular infections consisted of infected aneurysms (68%) or prosthetic graft infections (32%); vascular rupture was reported in 25/42 (60%). Tissue samples grew L. monocytogenes in 98% (43/44) and blood cultures in 64% (27/42). Endocarditis cases involved prosthetic or native valves or intracardiac devices in respectively 62% (18/29), 28% (8/29) and 10% (3/29). Infected valves were aortic (62%, 16/26), mitral (31%, 8/26) or both (8%, 2/26); 38% patients required surgery; 45% displayed heart failure; 17% had concomitant neurolisteriosis. In-hospital mortality in vascular infections was 12% (5/42) and 41% (12/29) for Lm-associated endocarditis. Endovascular listeriosis is a rare but severe infection. It manifests as vascular infections and endocarditis, mostly in older patients with vascular or cardiac valve prosthetic devices and co-morbidities. Mortality in Lm-associated endocarditis is twice higher than with other pathogens, requiring prompt recognition and treatment.

Methodology for Hemodynamic Assessment of a Three-Dimensional Printed Patient-Specific Vascular Test Device

Assessing hemodynamics in vasculature is important for the development of cardiovascular diagnostic parameters and evaluation of medical devices. Benchtop experiments are a safe and comprehensive preclinical method for testing new diagnostic endpoints and devices within a controlled environment. Recent advances in three-dimensional (3D) printing have enhanced benchtop tests by allowing generation of patient-specific and pathophysiologic conditions. We used 3D printing, coupled with image processing and computer-aided design (CAD), to develop a patient-specific vascular test device from clinical data. The proximal pulmonary artery (PA) tree including the main, left, and right pulmonary arteries, with a stenosis within the left PA was selected as a representative anatomy for developing the vascular test device. Three test devices representing clinically relevant stenosis severities, 90%, 80%, and 70% area stenosis, were evaluated at different cardiac outputs (COs). A mock circulatory loop (MCL) generating pathophysiologic pulmonary pressure and flow was used to evaluate the hemodynamics within the devices. The dimensionless pressure drop–velocity ratio characteristic curves for the three stenosis severities were obtained. At a fixed CO, the dimensionless pressure drop increased nonlinearly with an increase in (a) the velocity ratio for a fixed stenosis severity and (b) the stenosis severity at a specific velocity ratio. The dimensionless pressure drop observed in vivo was similar (within 1%) to that measured in moderate area stenosis of 70% because both flows were viscous dominated. The hemodynamics of the 3D printed test device can be used for evaluating diagnostic endpoints and medical devices in a preclinical setting under realistic conditions.

The Frontoparietal Fossa and Dorsotemporal Fenestra of Archosaurs and Their Significance for Interpretations of Vascular and Muscular Anatomy in Dinosaurs.

The attachments of jaw muscles are typically implicated in the evolution and shape of the dorsotemporal fenestra on the skull roof of amniotes. However, the dorsotemporal fenestrae of many archosaurian reptiles possess smooth excavations rostral and dorsal to the dorsotemporal fossa which closely neighbors the dorsotemporal fenestra and jaw muscle attachments. Previous research has typically identified this region, here termed the frontoparietal fossa, to also have attachment surfaces for jaw-closing muscles. However, numerous observations of extant and extinct archosaurs described here suggest that other tissues are instead responsible for the size and shape of the frontoparietal fossa. This study reviewed the anatomical evidence that support soft-tissue hypotheses of the frontoparietal fossa and its phylogenetic distribution among sauropsids. Soft-tissue hypotheses (i.e., muscle, pneumatic sinus, vascular tissues) were analyzed using anatomical, imaging and in vivo thermography techniques within a phylogenetic framework using extant and extinct taxa to determine the inferential power underlying the reconstruction of the soft tissues in the skull roofs of dinosaurs, pseudosuchians, and other reptiles. Relevant anatomical features argue for rejection of the default hypothesis-that the fossa was muscular-due to a complete lack of osteological correlates reflective of muscle attachment. The most-supported inference of soft tissues is that the frontoparietal fossa contained a large vascular structure and adipose tissue. Despite the large sizes and diverse morphologies of these fossae found among dinosaur taxa, these data suggest that non-avian dinosaurs had the anatomical foundation to support physiologically significant vascular devices and/or vascular integumentary structures on their skull roofs. Anat Rec, 303:1060-1074, 2020. © 2019 Wiley Periodicals, Inc.

Identifying the underlying causes of hospital-onset Staphylococcus aureus bacteremia: A retrospective analysis

BACKGROUND Laboratory-based reporting of hospital-onset (HO) Methicillin-Resistant Staphylococcus aureus (MRSA) bacteremia is used by regulatory agencies as a method to decrease the incidence of MRSA bacteremia in acute care settings. Although decolonization, hand hygiene, and isolation strategies are used, many facilities continue to have high rates of HO-MRSA. To better understand the potential risk factors and underlying causes of patients developing a HO-MRSA bacteremia, a chart review of patients that developed a HO Staphylococcus aureus (SA) and meeting defined criteria was reviewed to identify potential strategies towards prevention efforts. METHODS Laboratory data was pulled from January 2016 – July 2017. Data included in the export were all positive blood cultures that grew MSSA and MRSA. The data was further filtered to only include first incident blood cultures growing MSSA or MRSA that occurred on or after the fourth day of hospitalization. Chart review was performed to identify risk factors and clinical syndromes that could potentially lead to a HO-SA bacteremia. RESULTS We identified 130 inpatients with HO-SA bacteremia, of which 63 (48%) was HO-MRSA. The most common sources identified for patients with these bacteremias were pneumonia (27%), vascular devices (20%), and skin/soft tissue infections (23%). There was no significant difference in the distribution of these sources comparing HO-MRSA with HO-MSSA. A total of 42 (32%) patients were identified to have signs and symptoms consistent with infection on admission but did not have a blood culture collected on or after day 4 of admission. Of these 42 patients, 33 (79%) were admitted from the ED and 20 (48%) are immunosuppressed patients. CONCLUSIONS Pneumonia was the most common cause of HO-SA bacteremia. Strategies to prevent HO-MRSA should include processes to prevent hospital acquired pneumonia with prompt blood culture collection on admission in patients presenting with compatable signs and symptoms.

USING HYDROXYAPATITE POWDER (HAP) IN COATING OF STAINLESS-STEEL SUBSTRATE FOR BIO-APPLIATION (A REVIEW)

Around the world about millions of people using the medical devices or biomaterialsthat implanted in side human body in order to replace the function of unwell tissues ordamaged parts. In spite of the importance roles of these implants in saving or improvinghuman life, many of them are failed during short period or having complications. The mainfailure of the biomaterials caused by unqualified biocompatibility. Thus there are twomaterials types used for this field investment such as thin film nitinol and stainless steel.Stainless-Steel type 316L are widely used in biomaterial bone applications specially fixingdevices such as plates, screws, pins and artificial joints. On the other hands, thin film nitinolindicates a high possibility for applying in a small new vascular devices like heart valvesand covering stent grafts because of the singular beneficial properties of this material likesuper-elasticity and low-profile feature.

Creating a pragmatic trials program for breast cancer patients: Rethinking Clinical Trials (REaCT).

The proportion of breast cancer patients enrolled in clinical trials is falling. The Rethinking Clinical Trials (REaCT) program was developed to challenge some of the contemporary barriers responsible for this fall in accrual. In this article, we review the successes and challenges our program has faced. The REaCT program was created to improve care and outcomes for cancer patients through surveys of patients and healthcare providers, systematic reviews, economic evaluations, and the performance of pragmatic randomized trials with patient-centered outcomes. Likely, the greatest difference to conventional trial methodologies has been our widespread use of the integrated consent model (ICM) incorporating oral consent. Between 2014 and 2018, the program has recruited over 2000 patients to 15 randomized studies at 11 Canadian cancer centers. The REaCT program has completed and published five patient surveys, six healthcare provider surveys, ten systematic reviews, performed four economic evaluations, opened 15 clinical trials comparing standard of care interventions (two surgical, two adjuvant chemotherapy, five adjuvant supportive care, one radiology, two vascular devices, two palliative supportive care, and one molecular diagnostics). Patient surveys have shown high levels of satisfaction with the ICM. The REaCT program was developed to tackle important practice questions that will better guide optimal practice and to increase the availability of pragmatic clinical trials. While many challenges remain, future strategies will involve including more study sites and efforts to integrate novel information technology strategies.

Intrathrombus polymer coating deposition: a pilot study of 91 patients undergoing endovascular therapy for acute large vessel stroke. Part I: Histologic frequency

BackgroundPolymer coating embolism due to vascular medical device use is an increasingly recognized iatrogenic complication. This phenomenon has been linked with various adverse effects including neuroinflammation, acute ischemic stroke, cerebral...

The Influence of Polymer Processing Methods on Polymer Film Physical Properties and Vascular Cell Responsiveness.

Implantable vascular devices typically interface with blood and vascular tissues. Physical properties of device materials and coatings, independent of chemical composition, can significantly influence cell responses and implant success. Here, we analyzed the effect of various polymer processing regimes, using a single implant polymer - poly(ε-caprolactone) (PCL), on vascular endothelial cell (EC), smooth muscle cell (SMC), and platelet response. PCL films were formed by varying three parameters: 1) formation method - solvent casting, melt pressing or spin coating; 2) molecular weight - 50 or 100 kDa; and 3) solvent type - dichloromethane (DCM) or tetrahydrofuran (THF). We quantified the relationship of polymer processing choice to surface roughness, wettability, and bulk stiffness; and to EC adhesion, SMC adhesion, and platelet activity state (PAS). Multiple regression analysis identified which processing method signficantly impacted (F-ratio>p-value; p<0.1) polymer physical properties and vascular cell interaction. Film formation method affected PCL roughness (Rq), wettability (°), and stiffness (MPa) with spin coating resulting in the most wettable (81.8±0.7°), and stiffest (1.12±0.07 MPa; p<0.001) polymer film; however, solvent cast films were the roughest (281±66nm). Molecular weight influenced wettability, with the highest wettability on 50 kDa films (79.7±0.7°; p<0.001) and DCM solvent films (83.0±1.0°; p<0.01). The multiple regression model confidently predicted (F-ratio=9.88; p=0.005) wettability from molecular weight (p=0.002) and film formation method (p=0.03); stiffness (F-ratio=4.21; p=0.05) also fit well tofilm formation method (p=0.02). Film formation method impacted SMC adhesion and platelet activity state, but not EC adhesion, with melt press PCL promoting the highest SMC adhesion (18000±1536 SMCs; p<0.05) and PAS (5.0±0.7 %PAS). The regression model confidently fit SMC adhesion (F-ratio=3.15; p=0.09) and PAS (F-ratio=5.30; p=0.05) to polymer processing choices, specifically film formation method (p<0.03). However, only SMC adhesion had a model that fit well (F-ratio=4.13; p=0.05) to the physical properties directly, specifically roughness and wettability (p<0.04).