Intravascular Catheter Research Articles

Rare case of resistant Achromobacter xylosoxidans-associated meningitis due to intrathecal catheter

Background: Achromobacter xylosoxidans (AX) is an aerobic Gram-negative opportunistic bacteria known to inhabit various environments and is most commonly associated with nosocomial infections in immune-compromised patients. Although rare, AX can cause a variety of neurological infections, such as meningitis, ventriculitis, and osteomyelitis. Intravascular catheters, intrathecal pumps, and contaminated surgical instruments are potential vectors for such patients. Case Description: Here, we present a unique case of multidrug-resistant AX-positive meningitis secondary to infection of a nonfunctional intrathecal narcotic pump. The patient has a complex past medical history leading up to infection, and care was significantly compromised by homelessness and inflammatory bowel disease (IBD). Treatment included catheter removal and antibiotics. Conclusion: Patients who suffer from homelessness or IBD show a possible increased risk of this infection. This case emphasizes the need for increased care regarding these patients, along with describing the complications and timeline when treating this rare type of meningitis.

Risk Analysis of Intravascular Shockwave Catheter and Discussion of Critical Control Points throughout Life Cycle

This study summarizes the clinical application, technical characteristics, and production process of intravascular shockwave catheters. It collects statistics on adverse events of related products from the MAUDE database, analyzes the causes of adverse events and failure modes of intravascular shockwave catheters, and identifies risk points. Based on the whole life cycle management method of medical devices, combined with product risks and the requirements of Good Manufacturing Practice for Medical Devices and related appendices, the critical control points of such products in the design and development, manufacturing, sales, and use stages are discussed.

Investigation of Chlorhexidine and Chitosan Gel-Based Coatings for the Prevention of Intravascular Catheter-Associated Infections Following Quality by Design Approach.

Intravascular catheter-associated infections pose a significant threat to the health of patients because of biofilm formation. Hence, it is imperative to exploit cost-effective approaches to improve patient compliance. With this aim, our present study reported the potential of an antimicrobial polymeric gel coating of chitosan (CS) and chlorhexidine (CHX) on the marketed urinary catheters to minimize the risk of biofilm formation. The study involved the implementation of the Quality by Design (QbD) approach by identifying the critical parameters that can affect the coating of the catheter's surface in any possible way. Later, design of experiments (DoE) analysis affirmed the lack of linearity in the model for the studied responses in a holistic manner. Moreover, in vitro studies were conducted for the evaluation of various parameters followed by the antibiofilm study. The coating exhibited promising release of CHX in the artificial urinary media together with retention of the coating on the catheter's surface. Therefore, this study aims to emphasize the importance of a systematic and quality-focused approach by contributing to the development of a safe, effective, and reliable catheter coating to enhance intravascular catheter safety.

Transportable, portable, wearable and (partially) implantable haemodialysis systems: comparison of technologies and readiness levels

ABSTRACT Background Dialysis modalities and their various treatment schedules result from complex compromises (‘trade-offs’) between medical, financial, technological, ergonomic, and ecological factors. This study targets summarizing the mutual influence of these trade-offs on (trans)portable, wearable, or even (partially) implantable haemodialysis (HD) systems, identify what systems are in development, and how they might improve quality of life (QoL) for patients with kidney failure. Methods HD as defined by international standard IEC 60601–2-16 was applied on a PUBMED database query regarding (trans)portable, wearable, and (partly) implantable HD systems. Out of 159 search results, 24 were included and scanned for specific HD devices and/or HD systems in development. Additional information about weight, size, and development status was collected by the internet and/or contacting manufacturers. International airplane hand baggage criteria formed the boundary between transportable and portable. Technology readiness levels (TRLs) were assigned by combining TRL scales from the European Union and NATO medical staff. Results The query revealed 13 devices/projects: seven transportable (six TRL9, one TRL5); two portable (one TRL6–7, one TRL4); two wearable (one TRL6, one frozen); and two partly implantable (one TRL4–5, one TRL2–3). Discussion Three main categories of technical approaches were distinguished: single-pass, dialysate regenerating, and implantable HD filter with extracorporeal dialysate regeneration (in climbing order of mobility). Conclusions Kidneys facilitate mobility by excreting strongly concentrated waste solutes with minimal water loss. Mimicking this kidney function can increase HD system mobility. Dialysate-regenerating HD systems are enablers for portability/wearability and, combined with durable implantable HD filters (once available), they may enable HD without needles or intravascular catheters. However, lack of funding severely hampers progress.

HOCl Production Modelling for an Electrochemical Catheter

Intravascular catheters are used in critically ill patients to deliver fluids and lifesaving medications, and for hemodynamic monitoring. These catheters are at risk for infection, especially when in place for prolonged periods of time. The management of catheter-related infections are challenged by both the presence of biofilms and the frequent association with multidrug-resistant organisms. Efforts to mitigate central line-associated bloodstream infections (CLABSIs) have focused on preventive measures. Several strategies to prevent intraluminally sourced CLABSI have been developed and used, including antimicrobial agent locks and antimicrobial-impregnated catheter lumens. Although antimicrobial locks have reduced CLABSI rates, this strategy is prone to complications, including resistance selection, allergic reactions, catheter damage, and host toxicity due to the high concentrations of agents needed. Largely because of these factors, antimicrobial locks are infrequently used for CLABSI prevention in clinical practice. Antimicrobial impregnated catheter lumens have also shown variable effects against CLABSI and are likewise not regularly used. Therefore. innovative therapeutic solutions are necessary, especially those that allow catheter retention. In this context, the integration of electrochemical technologies for hypochlorous acid (HOCl) production within intravascular catheters emerges as a promising strategy to combat CLABSIs. HOCl is a strong oxidizing agent that damages microbial cells by interacting with lipids, nucleic acids, sulfur-containing amino acids, and membrane components. It is found in all mammals as an endogenous substance produced by the immune system to protect the body from pathogens. In this study, electrochemical generation of HOCl in an electrochemical catheter (e-catheter) was simulated using a model called Electrochemical Hypochlorous Acid Production (EHAP), implemented in COMSOL Multiphysics®. The e-catheter has two components, a hub and a tube, both filled with 0.9% saline solution. Titanium wires are used as working and counter electrodes.The model was used to define critical variables that may impact HOCl generation and distribution. In addition to predicting HOCl concentrations, the EHAP model was used to monitor effects of 1) a waiting period after constant polarization, 2) operational voltage, 3) working electrode length and 4) working electrode surface area. Findings using the EHAP model revealed the following: 1) Diffusion limitations predominate when the electrodes are localized to the hub, yielding a lower HOCl concentration in the tube compared to the hub. Increasing the voltage between the working and the reference electrodes increases HOCl generation, however concentrations are not enough to deliver HOCl to the tube. 2) HOCl concentrations are higher in the tube compared to hub when the working electrode extends the entire length of the tube. 3) HOCl concentration distributions can be tuned by changing the surface area of the working electrode within different compartments of the e-catheter.

Part 1: Pushing the boundaries of neurointerventional surgery: A historical review of the work of Dr Gerard Debrun.

French-American neurointerventionalist and pioneer, Dr Gerard Debrun, laid the groundwork for treatments which have become irreplaceable in neurointerventional surgery today. This article aims to outline the career of Dr Debrun while highlighting his accomplishments and contributions to the field of neurointerventional surgery. We selected relevant articles from PubMed authored or co-authored by Dr Debrun between 1941 and 2023. All included articles discuss the accomplishments and contributions of Dr Debrun. Dr Debrun began his career in France by investigating neurointerventional techniques, most notably the intravascular Detachable Balloon Catheter (DBC). His work was recognized by renowned neurosurgeon Dr Charles Drake, who recruited him to London, Ontario. Dr Debrun created the foundation for homemade manufacturing of DBCs, building on one of the largest series for use of DBCs in cerebrovascular disease. Dr Debrun spent time as faculty at Massachusetts General Hospital (MGH) and Johns Hopkins Hospital, before arriving at the University of Illinois Chicago (UIC) where he remained until his retirement. Dr Debrun's subsequent contributions included the calibrated-leak balloon catheter, pioneering of glue embolization, setting the foundation for preoperative AVM embolizations, and as an early adopter of the Guglielmi detachable coil (GDC), including mastering the balloon remodeling technique for wide neck aneurysms. Dr Debrun established the first integrated neurointerventional surgery program at UIC, establishing a well sought-after fellowship program. Dr Debrun lectured extensively and was a prolific writer on neurointerventional surgery throughout this career. His contributions established the foundation for several techniques which have since become standard practice in present-day neurointerventional surgery.

Evaluation of the Efficiency of the Newly Developed Needle in Emergency Room: A Single-Center Observational Study.

Peripheral intravascular catheter (PIVC) insertion is frequently performed in the emergency room (ER) and many failures of initial PIVC insertion occur. To reduce the failures, new needles were developed. This study aimed to investigate whether the use of the newly developed needle reduced the failure of initial PIVC insertion in the ER compared with the use of the existing needle. This single-centre, prospective observational study was conducted in Japan between April 1, 2022, and February 2, 2023. We included consecutive patients who visited our hospital by ambulance as a secondary emergency on a weekday during the day shift (from 8:00 AM to 5:00 PM). The practitioners for PIVC insertion and assessors were independent. The primary and secondary outcomes were the failure of initial PIVC insertion and number of procedures, respectively. We defined the difficulty of titrating, leakage, and hematoma within 30 s after insertion as failures. To evaluate the association between the outcomes and the use of newly developed needles, we performed multivariate logistic regression and multiple regression analyses by adjusting for covariates. In total, 522 patients without missing data were analysed, and 81 (15.5%) patients showed failure of initial PIVC insertion. The median number of procedures (interquartile range) was 1 (1-1). Multivariate logistic regression analysis revealed no significant association between the use of newly developed PIVCs and the failure of initial PIVC insertion (odds ratio, 0.79; 95% confidence interval, [0.48-1.31]; p = 0.36). Moreover, multiple regression analysis revealed no significant association between the use of newly developed PIVCs and the number of procedures (regression coefficient, -0.0042; 95% confidence interval, [-0.065-0.056]; p = 0.89). Our study did not show a difference between the two types of needles with respect to the failure of initial PIVC insertion and the number of procedures.

Development of a Machine Learning-Based Model for Predicting the Incidence of Peripheral Intravenous Catheter-Associated Phlebitis.

Early and accurate identification of high-risk patients with peripheral intravascular catheter (PIVC)-related phlebitis is vital to prevent medical device-related complications. This study aimed to develop and validate a machine learning-based model for predicting the incidence of PIVC-related phlebitis in critically ill patients. Four machine learning models were created using data from patients ≥ 18 years with a newly inserted PIVC during intensive care unit admission. Models were developed and validated using a 7:3 split. Random survival forest (RSF) was used to create predictive models for time-to-event outcomes. Logistic regression with least absolute reduction and selection operator (LASSO), random forest (RF), and gradient boosting decision tree were used to develop predictive models that treat outcome as a binary variable. Cox proportional hazards (COX) and logistic regression (LR) were used as comparators for time-to-event and binary outcomes, respectively. The final cohort had 3429 PIVCs, which were divided into the development cohort (2400 PIVCs) and validation cohort (1029 PIVCs). The c-statistic (95% confidence interval) of the models in the validation cohort for discrimination were as follows: RSF, 0.689 (0.627-0.750); LASSO, 0.664 (0.610-0.717); RF, 0.699 (0.645-0.753); gradient boosting tree, 0.699 (0.647-0.750); COX, 0.516 (0.454-0.578); and LR, 0.633 (0.575-0.691). No significant difference was observed among the c-statistic of the four models for binary outcome. However, RSF had a higher c-statistic than COX. The important predictive factors in RSF included inserted site, catheter material, age, and nicardipine, whereas those in RF included catheter dwell duration, nicardipine, and age. The RSF model for the survival time analysis of phlebitis occurrence showed relatively high prediction performance compared with the COX model. No significant differences in prediction performance were observed among the models with phlebitis occurrence as the binary outcome.

Regulation of candidalysin underlies Candida albicans persistence in intravascular catheters by modulating NETosis.

Candida albicans is a leading cause of intravascular catheter-related infections. The capacity for biofilm formation has been proposed to contribute to the persistence of this fungal pathogen on catheter surfaces. While efforts have been devoted to identifying microbial factors that modulate C. albicans biofilm formation in vitro, our understanding of the host factors that may shape C. albicans persistence in intravascular catheters is lacking. Here, we used multiphoton microscopy to characterize biofilms in intravascular catheters removed from candidiasis patients. We demonstrated that, NETosis, a type of neutrophil cell death with antimicrobial activity, was implicated in the interaction of immune cells with C. albicans in the catheters. The catheter isolates exhibited reduced filamentation and candidalysin gene expression, specifically in the total parenteral nutrition culture environment. Furthermore, we showed that the ablation of candidalysin expression in C. albicans reduced NETosis and conferred resistance to neutrophil-mediated fungal biofilm elimination. Our findings illustrate the role of neutrophil NETosis in modulating C. albicans biofilm persistence in an intravascular catheter, highlighting that C. albicans can benefit from reduced virulence expression to promote its persistence in an intravascular catheter.

Impact of Catheter-Drawn Blood Cultures on Patient Management: A Multicenter, Retrospective Cohort Study.

Nosocomial bloodstream infections associated with intravascular catheters pose significant financial burden, morbidity, and mortality. There is much debate about whether or not blood cultures should be drawn through central venous catheters, and while guidelines advocate for catheter-drawn cultures when catheter infection is suspected, there is variable practice in this regard. We performed a retrospective cohort study assessing episodes of positive catheter-drawn blood cultures with concomitant negative percutaneously-drawn cultures in tertiary care hospitals in the United States and Spain. We identified 143 episodes in 122 patients meeting inclusion criteria. Thirty percent of such episodes revealed growth of potential pathogens such as Staphylococcus aureus. Overall, 21% of follow-up percutaneously-drawn blood cultures obtained within 48 hours revealed growth of the same microbe after an episode of positive catheter-drawn blood cultures with negative concomitant percutaneously-drawn cultures (33% when potential pathogens were isolated; 16% when common skin contaminants were isolated). Patients with cultures growing pathogenic organisms were more likely to receive targeted antimicrobial therapy and have their catheters removed sooner. Many episodes of positive catheter-drawn blood cultures with concomitant negative percutaneously-drawn cultures lead to growth from percutaneously-drawn follow-up blood cultures. Thus, such initial discordant results should not be disregarded. Our findings advocate for a nuanced approach to blood culture interpretation, emphasizing the value of catheter-drawn blood cultures in clinical decision making and management.

Adherence to guidelines and central-line-associated bloodstream infection occurrence during insertion and maintenance of intravascular catheters: evidence from 20 tertiary hospitals

To investigate adherence to intravascular catheter (IVC) insertion and maintenance guidelines in Chinese tertiary hospitals. A cross-sectional questionnaire survey of adult inpatients with IVC placements was conducted from July to September 2022 in 20 tertiary hospitals in China. One clinical staff member from each department in each hospital was assigned to participate in the survey. Questionnaires were uniformly collected and reviewed after 3 months. This study included 1815 cases (62.69%) of central venous catheter, 471 cases (16.27%) of peripherally inserted central catheter, 461 cases (15.92%) of PORT, and 147 cases (5.08%) of haemodialysis catheter insertions. Statistically significant differences in compliance were observed across the four IVC types, specifically in relation to the insertion checklist, standard operating procedure, and insertion environment (P<0.05). Practice adherence during IVC maintenance differed significantly across the four IVC types in aspects such as availability of IVC maintenance verification forms, daily scrubbing of the catheterised patients, and catheter connection methods (P<0.05). A total of 386 (13.34%) patients developed fever, 1086 (37.53%) were treated with therapeutic antibiotics, 16 (0.55%) developed central line-associated bloodstream infections, two (0.07%) developed local skin infections, and six (0.21%) developed deep vein thrombosis. Adherence to guidelines regarding insertion and maintenance differed across the four IVC types; there is a gap between the recommended measures and the actual operation of the guideline. Therefore, it is necessary to further enhance training and develop checklists to prevent CLABSIs.

Rotational Intravascular Multidirectional Ultrasound Catheter for Sonothrombolysis of Retracted Clots: An in Vitro and in Vivo Study

Thromboembolism in blood vessels poses a serious risk of stroke, heart attack, and even sudden death if not properly managed. Sonothrombolysis combined with ultrasound contrast agents has emerged as a promising approach for the effective treatment of thromboembolism. Recent reports have highlighted the potential of intravascular sonothrombolysis as a safe and effective treatment modality for deep vein thrombosis (DVT). However, its efficiency has not been validated through in vivo testing of retracted clots. This study aimed to develop a miniaturized multidirectional transducer featuring two 4-layer lead zirconate titanate (PZT-5A) stacks with an aperture size of 1.4 mm × 1.4 mm, enabling both forward- and side-looking treatment. Integrated into a custom two-lumen 10-French (Fr) catheter, the capability of this device for intravascular sonothrombolysis was validated both in vitro and in vivo. With low-dose tissue plasminogen activators and nanodroplets, the rotational multidirectional transducer reduced the retracted clot mass (800 mg) by an average of 52% within 30 min during in vitro testing. The lysis rate was significantly higher by 37% than that in a forward-viewing transducer without rotation. This improvement was particularly noteworthy in the treatment of retracted clots. Notably, a long-retracted clot (> 10 cm) was successfully treated within 40 min in vivo by creating a flow channel with a diameter > 4 mm in a porcine DVT model. In conclusion, these findings strongly suggest the potential of this technique for clinical applications in sonothrombolysis, offering a feasible solution for effectively treating thromboembolism, particularly in challenging cases involving retracted clots.

Cavoatrial junction stenting in vascular hemodialysis catheter malfunction.

In patients undergoing hemodialytic treatment via intravascular catheters, stenosis or occlusion of central veins is common. Despite an extensive characterization of Superior Vena Cava Syndrome (SVCS) no data is available about CavoAtrial Junction (CAJ) stenosis. We report the case of two patients with a story of multiple catheter failures due to thrombosis or infection. Computed tomography (CT) showed radiological signs of CAJ stenosis confirmed at the following venography. In absence of other feasible options to place a vascular access, the two underwent stenting with Gore Viabahn VBX balloon expandable endoprosthesis (W.L. Gore & Associates, Flagstaff, AZ, USA) of the CAJ stenosis. Completion venography showed complete resolution of the stenosis in both patients. No complications occurred during the procedures. At a mean follow-up of 878 ± 559 days no signs of in-stent restenosis or recoil were found. The present cases emphasize the feasibility and safety of CAJ stenting, underlining the importance of preserving CAJ and upper veins patency in hemodialysis access.

Challenging repair of the left subclavian vein in a pediatric patient.

This is a case involving a 3-year-old child who presented with an iatrogenic left subclavian/innominate vein lesion, leading to severe bleeding and intravascular catheter rupture during its removal. We successfully performed a very challenging and minimally invasive repair of the vein, along with the removal of the catheter entrapped in the innominate vein.

A New, Safe, and Effective Technique for Percutaneous Insertion of a Peritoneal Dialysis Catheter.

A properly functioning peritoneal catheter is an essential element of effective peritoneal dialysis (PD). Currently, there are three techniques available for PD catheter placement, which include open surgery, laparoscopic surgery, and percutaneous catheter placement (PCP). Currently, no particular catheter placement approach has been proven with certainty to provide superior outcomes. We present a new modified PCP method with the use of the Veress needle covered with an intravascular catheter (IC) and preliminary clinical results of PD catheter placements with this new technique. The endpoints used in the study were 1-year technical survival of the catheter, and the incidence of early (1 month) mechanical as well as infection complications. The catheter was implanted in 24 patients. The catheter survival rate was 100%; however, in two cases, the catheters were removed due to complications not associated with PD treatment. No early mechanical complications such as bleeding, hematoma, perforations, internal organ damage, exit site leaks, or hernia in the place of insertion were observed. Similarly, no early infectious complications were observed. During the 1-year follow-up, no catheter migration occurred. Our results showed that the new PCP technique is a safe and easy procedure that minimizes the occurrence of both mechanical and infectious complications and ensures good catheter survival.

Reports on vascular catheter-associated thromboembolic events in a burn unit - a gap in the literature?

Indwelling intravascular catheters are important tools in the care of critically ill patients; however, they have an inherent risk of infection or thromboembolic events. Reports on catheter associated thromboembolic events in burn units are rare, despite being well recognized that burn patients bear an increased baseline risk for thromboembolic events. We describe two catheter-associated thromboembolic complications in burn patients in a burn unit and the morbidity associated with these events. Patients with endovascular catheters in burn units may be at increased risk for severe thromboembolic events associated with intravascular catheters, but specific guidelines for prevention and management of these patients are still missing.

Implementatie van de Infectierisicoscan in een ziekenhuisnetwerk door het Hospital Outbreak Support Team

Implementation of the Infection Risk Scan in a hospital network by the Hospital Outbreak Support Team The Infection Risk Scan (IRIS) assesses the quality of infection prevention and control (IPC) and antimicrobial stewardship (AMS) in a hospital ward by the standardized measurement of a broad range of quality indicators. IRIS was implemented in the geriatric wards of the 4 hospitals of the Plexus healthcare network ‘Oost-Vlaams-Brabant’ (Belgium). The goal was to compare the IPC and AMS policies of the hospitals in order to define common improvement strategies within the Hospital Outbreak Support Team (HOST), a federal project concerning IPC and AMS. In the first part of IRIS, the risk profile of the patient population is determined by a point prevalence measurement of 4 variables. In the second part, the improvement plot is created based on the measurement of 7 quality indicators. Improvement actions can be deduced from quality indicators with higher improvement potentials. The risk profiles of the 4 hospitals were highly comparable and the improvement plots showed an intermediate to high improvement potential for the use of AMT and hand hygiene compliance. There were important differences in the appropriate use of transurethral and intravascular catheters, with 2 hospitals having a low and 2 hospitals having a high improvement potential. IRIS was a useful tool in the early phase of the HOST project to benchmark the IPC and AMT policies between the Plexus hospitals and to decide what future projects could be collaborated on. As a result of IRIS, it was decided to define common care bundles for the prevention of catheter-associated urinary tract and blood stream infections and to determine hospital-specific actions with regard to the optimisation of AMS.

Adrenaline and Anesthesia - Clinical Review

Abstract Adrenaline or epinephrine is one of the primarily important catecholamines in the general stress response and is manufactured in the adrenal medulla. In stress, it is secreted into the blood circulation and evokes many bodily transformations which prepare the body for the fight or flight response, some of which include tachycardia and hypertension, dilation of the air passages, and mobilization of energy reserves. This catecholamine surge can, however, cause myocardial stress, as evidenced during acute ischemia, hence an implication of increased risk of myocardial injury. In terms of functioning at the molecular level, adrenaline interacts with adrenergic receptors, which trigger intracellular processes associated with the readiness of a body to act fast as well as affecting more general forms of cardiac activity. Adrenaline stimulates beta-adrenergic receptors, enhancing heart rate and contractility, vital under stress but harmful with constant exposure. It is metabolized in the liver and may also cause dysrhythmias when used together with some inhaled anesthesia such as halothane. In anesthesia, adrenaline gets used to increase the local anesthetic action of the drug by constricting blood vessels and thereby increasing the duration and extent of analgesia besides reducing the uptake of the anesthetic into the systemic circulation. The common dose schedule is 1 in 2 lakh of adrenaline which means 5 μ/mL. The usual dose should not increase to 3 μ/kg. Preferably, the dose can be supplemented after 10–15 min. The use of adrenaline also creates a plane to dissect. The duration of action of local anesthetic drug is prolonged following the addition of adrenaline. Epidural test doses detect accidental intravascular catheterization. There is evidence that adrenaline belongs to anesthetic protocols, enabling deeper anesthesia, which, in turn, contributes to more effective outcomes of the surgery and easier recovery. Adrenaline by way of its alpha 2 agonism is likely to increase the effects of local anesthetic drugs and inhalational agents. Still, practitioners must address those benefits against possible side effects since minor, albeit significant, changes in the electrocardiographic characteristics have been recorded with lignocaine–adrenaline mixtures. Adrenaline nebulization is used for acute respiratory conditions like croup postextubation. The dose is 0.5 mg/kg, max 5 mg, diluted in 2–3 mL saline, repeated every 30 min if needed, with monitoring for tachycardia and hypertension. For perioperative anaphylaxis, administer 0.5 mg intramuscular for adults, adjusted by age for children. Hence, adrenaline is extremely useful in local anesthesia because of its vasoconstrictive effects, which must, however, be monitored continuously for patient and operational safety.

Dual modality intravascular catheter system combining pulse-sampling fluorescence lifetime imaging and polarization-sensitive optical coherence tomography.

The clinical management of coronary artery disease and the prevention of acute coronary syndromes require knowledge of the underlying atherosclerotic plaque pathobiology. Hybrid imaging modalities capable of comprehensive assessment of biochemical and morphological plaques features can address this need. Here we report the first implementation of an intravascular catheter system combining fluorescence lifetime imaging (FLIm) with polarization-sensitive optical coherence tomography (PSOCT). This system provides multi-scale assessment of plaque structure and composition via high spatial resolution morphology from OCT, polarimetry-derived tissue microstructure, and biochemical composition from FLIm, without requiring any molecular contrast agent. This result was achieved with a low profile (2.7 Fr) double-clad fiber (DCF) catheter and high speed (100 fps B-scan rate, 40 mm/s pullback speed) console. Use of a DCF and broadband rotary junction required extensive optimization to mitigate the reduction in OCT performance originating from additional reflections and multipath artifacts. This challenge was addressed by the development of a broad-band (UV-visible-IR), high return loss (47 dB) rotary junction. We demonstrate in phantoms, ex vivo swine coronary specimens and in vivo swine heart (percutaneous coronary access) that the FLIm-PSOCT catheter system can simultaneously acquire co-registered FLIm data over four distinct spectral bands (380/20 nm, 400/20 nm, 452/45 nm, 540/45 nm) and PSOCT backscattered intensity, birefringence, and depolarization. The unique ability to collect complementary information from tissue (e.g., morphology, extracellular matrix composition, inflammation) with a device suitable for percutaneous coronary intervention offers new opportunities for cardiovascular research and clinical diagnosis.

A technique to retrieve an internalised embedded central venous catheter

BackgroundCentral venous catheters may become embedded due to the formation of adhesions between the indwelling catheter and the vein wall.Case presentationA 49-year-old patient with bacteraemia was referred for retrieval of an embedded internalised central venous dialysis catheter. Recently the catheter had been surgically ligated at the venotomy site internalising the intravascular catheter component, which precluded antegrade ballooning through the catheter hub.Seldinger technique was used to access the catheter lumen within the left internal jugular vein and through and through access was established across the catheter. Retrograde endoluminal balloon dilation was performed to disrupt adhesions and free the catheter. The catheter was snared over the wire and removed from the right femoral vein.ConclusionThis case report outlines an effective, minimally invasive retrieval method in a rare case of an embedded internalised central venous catheter.Graphical