Recent Advances in Arteriovenous Access Creation for Hemodialysis: New Horizons in Dialysis Vascular Access.

Recent advances in technology show promise in providing greater vascular access options for hemodialysis patients. This review discusses novel methods for creating an anastomosis for arteriovenous (AV) fistulas and new materials for prosthetic AV grafts. Two technologies for endovascular arteriovenous fistula creation, the Ellipsys and WavelinQ endovascular systems, are discussed. When an AV fistula is not possible, an AV graft or devices to augment the AV fistula may be appropriate. New materials that have been developed that show promise as an alternative to the expanded polytetrafluoroethylene graft are discussed. Such potential conduits include bioengineered vessels and both allogenic or xenogenic biologic grafts. Devices designed to optimize blood flow to reduce maturation failure and improve AV fistula outcomes are explored.

Challenges of Vascular Access in the Pediatric Population.

The incidence and prevalence of renal replacement therapy has continued to increase in the pediatric population. Recent data have shown that hemodialysis was the most frequently used dialysis modality, especially in pediatric ESRD patients (age 0-21 years). A well-functioning vascular access is required for effective hemodialysis and choosing the best vascular access option for pediatric patients can be difficult. Pediatric vascular options include arteriovenous fistula, arteriovenous graft, and central venous catheters (CVCs). There is a national initiative for fistula first-catheter last approach; however, CVCs have been reported as the most conventionally utilized vascular access option in pediatric patients. The use of CVCs should be minimized or avoided as they are associated with high risk of infections, thrombosis, and other complications. Thus, it is important for practitioners to plan appropriately in advance, practice good clinical judgment, and assure that the best vascular access is placed according to the patient's needs. Therefore, this article reviews the different types of pediatric vascular access and the associated benefits and potential complications of each.

Rates of Venous Thromboembolism and Central Line-Associated Bloodstream Infections Among Types of Central Venous Access Devices in Critically Ill Children.

OBJECTIVES: Central venous access devices, including peripherally inserted central catheters and central venous catheters, are often needed in critically ill patients, but also are associated with complications, including central-line associated bloodstream infections and venous thromboembolism. We compared different central venous access device types and these complications in the PICU. DESIGN: Multicenter, cohort study. SETTING: One hundred forty-eight participating Virtual PICU Systems, LLC, hospital PICU sites. PATIENTS: Pediatric patients with central venous access placed from January 1, 2010, to December 31, 2015. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patient and central venous access device variables postulated to be associated with central-line associated bloodstream infection and venous thromboembolism were included. Data were analyzed using Pearson chi-square test or Fisher exact test for categorical variables, Mann-Whitney U test for continuous variables, and logistic regression and classification trees for multivariable analysis that examined significant predictors of venous thromboembolism or central-line associated bloodstream infection. Analysis included 74,196 first lines including 4,493 peripherally inserted central catheters and 66,194 central venous catheters. An increased rate of venous thromboembolism (peripherally inserted central catheter: 0.93%, central venous catheter: 0.52%; p = 0.001) (peripherally inserted central catheter: 8.65/1,000 line days, central venous catheter: 6.29/1,000 line days) and central-line associated bloodstream infection (peripherally inserted central catheter: 0.73%, central venous catheter: 0.24%; p = 0.001) (peripherally inserted central catheter: 10.82/1,000 line days, central venous catheter: 4.97/1,000 line days) occurred in peripherally inserted central catheters. In multivariable analysis, central venous catheters had decreased association with central-line associated bloodstream infection (odds ratio, 0.505; 95% CI, 0.336-0.759; p = 0.001) and venous thromboembolism (odds ratio, 0.569; 95% CI, 0.330-0.982; p = 0.043) compared with peripherally inserted central catheters. CONCLUSIONS: Peripherally inserted central catheters are associated with higher rates of central-line associated bloodstream infection and venous thromboembolism than central venous catheters in children admitted to the PICU.

Feasibility of kissing balloon technique through guide extension catheters: an experimental bench test.

Previous reports showed that GuideLiner (GL) and Guidezilla (GZ) can accommodate bulky and multiple devices beyond the official profiles. However, feasibility of kissing balloon technique (KBT) through these devices is unknown. The tested devices included 7Fr-GL/GZ and respective three types of 2.5 mm semi-compliant (SC) and non-compliant (NC) balloons: conventional model (CM), tapered-tip model (TM) and latest model (LM). First, three experienced operators attempted to advance all 21 combinations of the 2 balloons through GL/GZ on the guidewires and assessed the crossability in 3 grades: easy, difficult and impossible. Second, the only balloon combinations graded as easy by all operators were tested in the polyurethane-made bifurcation model which required KBT following cross-over stenting. Within the total of 42 device combinations, only one balloon combination of double LM-NC balloons was classified as easy in both GL/GZ by consensus opinion of the operators. While two combinations of LM-SC and LM-SC/NC balloons were classified as difficult in both GL/GZ, all four combinations of LM-SC/NC and CM/TM-NC balloons were classified as difficult only in GL. Other 32 combinations were all classified as impossible. In the bifurcation model, the combination of double LM-NC balloons using GL achieved KBT while the same balloon combination with GZ failed. The feasibility of KBT using child-catheter is highly dependent on the device characteristics. The combination of latest small-profile NC balloons through GL could be clinically applicable.

Comparison of complications with a 1.25-mm versus a 1.5-mm burr for severely calcified lesions that could not be crossed by an intravascular ultrasound catheter.

Since intravascular imaging such as intravascular ultrasound (IVUS) can provide useful information for rotational atherectomy (RA), intravascular imaging should be attempted before RA. However, some calcified lesions do not allow imaging catheters to cross before RA. Although small burrs (1.25 mm or 1.5 mm) should be selected for such tight lesions, it is unknown whether a 1.25-mm burr or 1.5-mm burr is safer as the initial burr. The aim of this study was to compare the incidence of complications with a 1.25-mm versus a 1.5-mm burr as the initial burr for IVUS-uncrossable lesions. This was a retrospective, single-center study. A total of 109 IVUS-uncrossable lesions were included, and were divided into a 1.25-mm group (n =52) and a 1.5-mm group (n =57). The incidence of slow flow just after RA was not different between the 2 groups (1.25-mm group: 25%, 1.5-mm group: 31.6%, P =0.45). The incidence of peri-procedural MI with slow flow was not different and equally low in the 2 groups (1.25-mm group: 1.9%, 1.5-mm group: 3.5%, P =0.61). The use of the 1.5-mm burr as the initial burr was not significantly associated with slow flow after controlling for chronic renal failure on hemodialysis and reference diameter (vs. 1.25-mm: OR 2.34, 95% CI 0.89-6.19, P =0.09). In conclusion, the incidence of complications following RA was comparable between the 1.25-mm and the 1.5-mm burrs as the initial burr for IVUS-uncrossable lesions. The present study provides insights into the selection of an appropriate burr for IVUS-uncrossable lesions.

Long peripheral catheters: Is it time to address the confusion?

Long peripheral catheters are 6-15 cm peripheral dwelling catheters that are inserted via a catheter-over-needle or direct Seldinger (catheter-over-guidewire) technique. When inserted in the upper extremity, the distal tip terminates before reaching the axilla, typically no further than the mid-upper arm. This is distinct from a midline catheter, which is inserted via a modified Seldinger technique and terminates at the axilla. The nomenclature of this catheter is confusing and inconsistent. We have identified over a dozen labels in the literature, all describing the same device. These include '15 cm catheter', 'catheter inserted with a Seldinger method', 'extended dwell/midline peripheral catheter', 'Leaderflex line', 'long catheter', 'long IV catheter', 'long peripheral cannula', 'long peripheral catheter', 'long peripheral venous catheter', 'long polyurethane catheter', 'midline cannula', 'mini-midline', 'peripheral intravenous catheter', 'Seldinger catheter', 'short midline catheter', 'short long line' and 'ultrasound-guided peripheral intravenous catheter'. The purpose of this editorial is to achieve some level of standardisation in the nomenclature of this device. Is it time to address the confusion? We suggest adopting 'long peripheral catheter'. However, we encourage discussion and debate in reaching a consensus.

Association between delivery methods for red blood cell transfusion and the risk of venous thromboembolism: a longitudinal study.

BACKGROUND: Mechanisms of red blood cell delivery and their contribution to the incidence of venous thromboembolism are not well understood in the clinical setting. We assessed whether red blood cell transfusion through peripherally inserted central catheters (PICCs) affects the risk of venous thromboembolism compared with transfusion through non-PICC devices. METHODS: We implemented a prospective study between Jan 1, 2013, and Sept 12, 2015, in patients (age ≥18 years) admitted to a general medicine ward or intensive care unit who received a PICC for any reason during clinical care in 47 hospitals in Michigan, USA, with a maximum follow-up of 70 days. The exposure of interest was route of red blood cell transfusion. The primary outcome was symptomatic, radiographically confirmed, deep-vein thrombosis in the arm or leg or pulmonary embolism. We used Cox proportional hazards regression for analyses. FINDINGS: Venous thromboembolism developed in 482 (5%) of 10 604 patients with PICCs. Of 788 patients who received a red blood cell transfusion through a multi-lumen PICC, 61 had venous thromboembolism. The adjusted hazard ratio (HR) for venous thromboembolism in all patients whose transfusions were administered through a multi-lumen PICC was 1·96 (95% CI 1·47-2·61; p<0·0001) compared with patients not receiving a transfusion, and was 1·79 (1·09-2·95; p=0·022) compared with patients transfused through a peripheral intravenous line. Compared with delivery through a peripheral intravenous line, venous thromboembolism risk was not elevated if transfusions were delivered through a single-lumen PICC (HR 0·98, 95% CI 0·44-2·14; p=0·95) or central venous catheter (1·50, 0·77-2·91; p=0·23). For every red blood cell unit transfused through a PICC, there was a significantly increased risk of venous thromboembolism (adjusted HR 1·24, 95% CI 1·01-1·52; p=0·037). Patients who received a transfusion through a PICC in the left arm were significantly more likely to develop a deep-vein thrombosis in the ipsilateral arm compared with the contralateral side (HR 23·44, 95% CI 2·96-185·83; p=0·0028). Similarly, patients transfused through a right-sided PICC were more likely to develop deep-vein thrombosis in the ipsilateral arm (HR 3·37, 95% CI 1·02-11·14; p=0·047). INTERPRETATION: Red blood cell delivery through a multi-lumen PICC is associated with a greater risk of thrombosis than transfusion through a peripheral intravenous catheter. Careful monitoring for venous thromboembolism when transfusing red blood cells through multi-lumen PICCs seems necessary. FUNDING: Blue Cross Blue Shield of Michigan and Blue Care Network, as part of the BCBSM Value Partnerships program.

A Randomized Study of SheathLess vs Standard Guiding Catheters for Transradial Percutaneous Coronary Interventions.

BACKGROUND: The small diameter of radial arteries remains a major limitation of the transradial approach for percutaneous coronary intervention (PCI). Sheathless guiding catheters (GCs) might offer an advantage over standard GCs. METHODS: Between 2011 and 2013, we randomized 233 transradial PCIs performed in men with ostial or bifurcation lesions and in all women between standard GC (Medtronic Launcher; Minneapolis, MN) and the SheathLess Eaucath GC (Asahi Intecc, Aichi, Japan). RESULTS: Successful PCI using the transradial approach was not different between the groups (P = 0.74), however the rate of successful transradial PCI with the designated GC (ie, without crossover to the opposing GC) was superior in the SheathLess group compared with the standard GC group (96.5% vs 89.9%; P = 0.047). Safety end point (ie, absence of PCI complication, radial artery occlusion, perforation, pseudoaneurysm, and Early Discharge after Transradial Stenting of Coronary Arteries [EASY] hematoma grade ≥ 2) did not differ between the groups (60.5% in both groups). Mean PCI duration (45.1 minutes vs 45.9 minutes), fluoroscopy (20.1 minutes and 19.9 minutes), and cannulation times (3.6 minutes vs 3.7 minutes), contrast media volume (196 mL vs 187 mL) and conversion to transfemoral approach (1.8% vs 0.8%) were not different between the groups. Patients' subjective assessment revealed less arm pain during navigation of the SheathLess GC (1.9 ± 1.9 vs 4.8 ± 3.6; P < 0.001). Operators graded arm crossability as easier with the SheathLess GC (8.7 ± 1.5 vs 5.1 ± 3.5; P < 0.001). CONCLUSIONS: In selected coronary lesions requiring large-bore catheters in men and in all lesions in women, the SheathLess GC was superior to the standard GC for successful transradial PCI with the designated GC. The SheathLess GC was also associated with easier arm navigation and less patient discomfort.

Port type is a possible risk factor for implantable venous access port-related bloodstream infections and no sign of local infection predicts the growth of gram-negative bacilli.

BACKGROUND: Implantable venous access port (IVAP)-related blood stream infections (BSIs) are one of the most common complications of implantable venous ports. The risk factors and pathogens for IVAP-related BSIs are still controversial. METHODS: We retrospectively reviewed all patients who received IVAPs at a Hospital in Taiwan from January 1, 2011 to June 31, 2014. Two types of venous port, BardPort® 6.6 fr (Bard port) and Autosuture Chemosite® 7.5 fr (TYCO port) were used. All patients with clinically proven venous port-related BSIs were enrolled. RESULTS: A total of 552 patients were enrolled. There were 34 episodes of IVAP-related BSIs during the study period for a total incidence of 0.177 events/1000 catheter days. Port type (TYCO vs. Bard, HR = 7.105 (95% confidence interval (CI), 1.688-29.904), p = 0.0075), age > 65 years (HR = 2.320 (95 % CI, 1.179-4.564), p = 0.0148), and lung cancer (HR = 5.807 (95% CI, 2.946-11.447), p < 0.001) were risk factors for port infections. We also found that no local sign of infection was significantly associated with the growth of gram-negative bacilli (p = 0.031). CONCLUSIONS: TYCO venous ports, age > 65 years, and lung cancer were all significant risk factors for IVAP-related BSIs, and no sign of infection was significantly associated with the growth of gram-negative bacilli.

Safety aspects in patients on hemodialysis with catheters.

Central venous catheter (CVC)-related problems, risks and safety hazards are partly caused by different characteristics of the CVC-based access and their performance features. This chapter covers those issues in a chronological order, from factors related to the choice of the CVC, insertion site and insertion procedure itself, over those associated with CVC use and their monitoring up to safety hazards of interventional procedures. Not discussed are CVC infections as they are covered in a separate chapter in this book.

Gastroenterology-urology devices; reclassification of implanted blood access devices. Final rule.

The Food and Drug Administration (FDA) is issuing a final order to reclassify implanted blood access devices, a preamendments class III device, into class II (special controls) based on new information and subject to premarket notification and to further clarify the identification.

Flexible tip guides and intermediate catheters: two center experience and a proposed taxonomy.

BACKGROUND: Stable access to target lesions is foundational to endovascular therapy, be it in hemorrhagic or ischemic disease. Continued evolution in access technology has resulted in next generation catheters that afford improved trackability and proximal support. OBJECTIVE: Assess safety and patterns of use at two high volume centers, and conceptualize usage patterns. MATERIALS AND METHODS: A retrospective review of 608 cases in which a 'next generation' catheter was used during 2008-2010 at Cleveland Clinic (Cleveland, Ohio, USA) and throughout 2009-2010 at Emory University Hospital (Atlanta, Georgia, USA) was conducted, and the cases classified by indication. Catheter placement, distal most location, and related complications were recorded and experience summarized. We also reviewed the differences in the catheters and the rationale for catheter selection, as well as relative costs for each approach. RESULTS: 311 Neuron 053, 166 Neuron 070, 36 distal access catheter (DAC) 3.9 F, 61 DAC 4.3 F, and 34 DAC 5.2 F catheters were deployed. Of these, 459 placements were in the anterior circulation, 130 in the posterior circulation, 11 in the external carotid artery, and eight were used intravenously. Complication rates were 9/131 (6.9%) for the DAC catheter group, 16/311 (5.1%) for the Neuron 053 group, and 14/166 (8.4%) for the Neuron 070 group (p=0.37, χ(2) test). CONCLUSIONS: Next generation access catheters possess characteristics that blend qualities of traditional microcatheters and stiff guide catheters. There was no statistically significant difference in complication rates between the various catheter families in this small retrospective review, and the complication rates were similar to historical complication rates.

Transradial intervention via large-bore guide catheters: a study of coronary bifurcation disease treatment using the crush technique.

Transradial access for coronary intervention significantly reduces vascular complications and may be associated with a reduced risk of major adverse cardiovascular events. However, the small caliber of the radial artery has been considered a limitation to performing complex coronary intervention. Fifty-three patients with true bifurcation disease, in whom a two-stent strategy was felt to be indicated, were scheduled to undergo crush stenting via the transradial approach. Procedural outcome was recorded and 6- and 18-month clinical follow-up was performed. Successful crush stenting via the radial artery was performed in 51/55 lesions (93%). Crush stenting was performed in 53 lesions overall and successful final kissing inflation was achieved in 51/53 (96%). There were no in-hospital or procedural complications. The overall rate of death, myocardial infarction, or target vessel revascularization was 9.8% at 18-month follow-up. Complex percutaneous coronary intervention requiring large-bore catheters can be performed successfully in a high proportion of patients via the transradial approach. Crush stenting, with a very high rate of final kissing inflation, was associated in this series with excellent procedural and medium-term outcomes.