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Journal: The journal of vascular access

165

Vascular access problems are a daily occurrence in hemodialysis units. Loss of patency of the vascular access limits hemodialysis delivery and may result in underdialysis that leads to increased morbidity and mortality. Despite the known superiority of autogenous fistulae over grafts, autogenous fistulae also suffer from frequent development of stenosis and subsequent thrombosis. International guidelines recommend programmes for detection of stenosis and consequent correction in an attempt to reduce the rate of thrombosis. Physical examination of autogenous fistulae has recently been revisited as an important element in the assessment of stenotic lesions. Prospective observational studies have consistently demonstrated that physical examination performed by trained physicians is an accurate method for the diagnosis of fistula stenosis and, therefore, should be part of all surveillance protocols of the vascular access. However, to optimize hemodialysis access surveillance, hemodialysis practitioners may need to improve their skills in performing physical examination. The purpose of this article is to review the basics and drawbacks of physical examination for dialysis arteriovenous fistulae and to provide the reader with its diagnostic accuracy in the detection of arteriovenous fistula dysfunction, based on current published literature.

Concepts: Chronic kidney disease, Dialysis, Hemodialysis, Renal replacement therapy, Arteriovenous fistula, Fistula, Cimino fistula

26

Venous catheters provide access for hemodialysis (HD) when patients do not have functioning access device. Obstruction of jugular, femoral or even external iliac vessels further depletes options. Subclavian approach is prohibited. Catheterization of inferior vena cava requires specialized equipment and skills.

Concepts: Central venous catheter, Femoral artery, External iliac artery, Inferior vena cava, Deep vein thrombosis, Deep vein, Superior vena cava, External iliac vein

25

Vascular surgeons are essential in “lifeline” creation for hemodialysis patients and should be the central player in any multidisciplinary access service together with nephrologists, dialysis staff and interventional radiology. In this position, access surgeons are involved in complicated clinical decision making regarding primary and secondary access selection, which throughout the last decade has been largely aided, and influenced, by national and international guidelines as well as other initiatives. These recommendations, unanimously and appropriately, advocate the placement of native fistulas over synthetic grafts (the majority grafts from expanded polytetrafluoroethylene, ePTFE, herein referred to as PTFE) based on the superiority of fistulas with respect to complications such as infections and thrombosis. Nevertheless, the use of PTFE grafts for hemodialysis access is an accepted and firmly established alternative to native fistulas where data today reveal unwanted consequences to overinterpretation of established guidelines such as increased catheter use. This information highlights a need for an adjustment of access selection strategies based on patient-centered algorithms. Here, available results on PTFE graft performance in hemodialysis access is recapitulated, with respect to both conventional grafts and technical modifications, and conclude with a modified approach to primary access selection.

Concepts: Chronic kidney disease, Dialysis, Hemodialysis, Renal replacement therapy, Interventional radiology, Polytetrafluoroethylene, DuPont, Gore-Tex

25

Peripherally inserted central catheters (PICCs) are increasingly used in patients with cystic fibrosis (CF) or with non-CF bronchiectasis, but little data exist on catheter-related complications in this setting.

Concepts: Cystic fibrosis, Allergic bronchopulmonary aspergillosis, Bronchiectasis, Peripherally inserted central catheter

25

To determine postinsertion complication rate for peripherally inserted central catheters (PICCs), in particular the difference between silicone and polyurethane lines in general population groups as well as oncology and non-oncology patient groups.

Concepts: Rates, Reaction rate, Community Charge, Peripherally inserted central catheter

25

To evaluate the impact of a proactive surveillance program on functional access rate at the time of first dialysis.

Concepts: Programming language, Arteriovenous fistula

2

Purpose: Catheters are associated with worse clinical outcomes than fistulas and grafts in hemodialysis (HD) patients. One potential modifier of patient vascular access (VA) use is patient preference for a particular VA type. The purpose of this study is to identify predictors of patient VA preference that could be used to improve patient care.Methods: This study uses a cross-sectional sample of data from the Dialysis Outcomes and Practice Patterns Study (DOPPS 3, 2005-09), that includes 3815 HD patients from 224 facilities in 12 countries. Using multivariable models we measured associations between patient demographic and clinical characteristics, previous catheter use and patient preference for a catheter.Results: Patient preference for a catheter varied across countries, ranging from 1% of HD patients in Japan and 18% in the United States, to 42% to 44% in Belgium and Canada. Preference for a catheter was positively associated with age (adjusted odds ratio per 10 years=1.14; 95% CI=1.02-1.26), female sex (OR 1.49; 95% CI=1.15-1.93), and former (OR=2.61; 95% CI=1.66-4.12) or current catheter use (OR=60.3; 95% CI=36.5-99.8); catheter preference was inversely associated with time on dialysis (OR per three years=0.90; 95% CI=0.82-0.97). Conclusions: Considerable variation in patient VA preference was observed across countries, suggesting that patient VA preference may be influenced by sociocultural factors and thus could be modifiable. Catheter preference was greatest among current and former catheter users, suggesting that one way to influence patient VA preference may be to avoid catheter use whenever possible.

Concepts: Chronic kidney disease, Dialysis, Patient, Hemodialysis, Renal replacement therapy, Odds ratio, Catheter, Fistula

1

The most appropriate lock solution for central venous access devices is still to be defined. GAVeCeLT - the Italian group for venous access devices - has developed a consensus on the evidence-based criteria for the choice and the clinical use of the most appropriate lock solution for central venous catheters (excluding dialysis catheters).

Concepts: Developed country, Central venous catheter, Solutions, Solution, Catheter, Catheters, Peripheral venous catheter, Slovenia

1

Purpose: We report the first use of a sterile elastic exsanguination tourniquet (SET) in performing hemodialysis vascular access procedures in 27 patients. The main advantages of this tourniquet are the reduction of blood loss and need for possible transfusions. Additional benefits are the near-perfect exsanguination and excellent exposure of the operative field. Methods: This SET is a sterile elastic stockinet device that rolls up the arm starting from the hand by pulling on two handles. The elastic silicone ring provides sufficient pressure (220 ± 30 mmHg) to block arterial flow into the limb. The stockinet can be cut to provide access to the incision area while providing an additional sterile cover over the rest of the limb. Results: No transfusions were required in any patients. Minor adverse effects occurred in four patients, including a twisted vessel, a bleeding vascular branch, a tear in atrophic arm skin, and pain, all of which had resolved on subsequent follow-up. Operational recommendations to avoid these adverse effects are outlined. Conclusions: We conclude that this sterile elastic exsanguination tourniquet is effective and safe in preventing bleeding during upper extremity hemodialysis vascular access procedures.

Concepts: Blood, Hemodialysis, Bleeding, Upper limb, Limb, Exsanguination

1

Purpose: To explore the safety and efficacy of PRT-201. Methods: Randomized, double-blind, placebo-controlled, single-dose escalation study of PRT-201 (0.0033 to 9 mg) applied after arteriovenous fistula (AVF) creation. Participants were followed for one year. The primary outcome measure was safety. Efficacy measures were the proportion with intra-operative increases in AVF outflow vein diameter or blood flow ≥25% (primary), changes in outflow vein diameter and blood flow, AVF maturation and lumen stenosis by ultrasound criteria and AVF patency. Results: The adverse events in the PRT-201 group (n=45) were similar to those in the placebo group (n=21). There were no differences in the proportion with ≥25% increase in vein diameter or blood flow, successful maturation or lumen stenosis. There was no statistically significant difference in primary patency between the dose groups (placebo n=21, Low Dose n=16, Medium Dose n=17 and High Dose n=12). In a subgroup analysis that excluded three participants with early surgical failures, the hazard ratio (HR) for primary patency loss of Low Dose compared with placebo was 0.38 (95% CI 0.10-1.41, P=0.15). In a Cox model, Low Dose (HR 0.27, 95% CI 0.04-0.79, P=0.09), white race (HR 0.17, 95% CI 0.03-0.79, P=0.02), and age <65 years (HR 0.25, CI 0.05-1.15, P=0.08) were associated (P<0.10) with a decreased risk of primary patency loss. Conclusions: PRT-201 was not different from placebo for safety or efficacy measures. There was a suggestion for improved AVF primary patency with Low Dose PRT-201 that is now being studied in a larger clinical trial.

Concepts: Clinical trial, Blood, Statistical significance, Artery, Difference, Vein, Placebo, Arteriovenous fistula