Anastomosis: An opening created by surgical, traumatic, or pathological means between 2 normally separate spaces or organs.
Aneurysm: An abnormal blood-filled dilation of a blood vessel wall (most commonly in arteries) resulting from disease of the vessel wall.
Pseudoaneurysm: A vascular abnormality that resembles an aneurysm, but the outpouching is not limited by a true vessel wall, rather by external fibrous tissue.
Angioplasty: The repair of a blood vessel abnormality.
Percutaneous transluminal angioplasty: The repair of a lesion using an endoluminal approach, usually with a balloon that can be inflated to pressures up to 30 atmospheres.
Antibiotic lock: Instillation of an antibiotic solution into the lumen of a dialysis catheter for the entire interdialytic period; antibiotics tested include vancomycin, aminoglycosides, and minocycline.
Antimicrobial lock: Instillation of an antimicrobial solution into the lumen of a dialysis catheter for the entire interdialytic period; antimicrobial solutions include high-concentration citrate, high-concentration EDTA, and taurolidine.
Antimicrobial: Any agent capable of destroying or inhibiting the growth of microorganisms.
Antiseptic: Any agent capable of preventing infection by inhibiting the growth of microorganisms.
Cannulation: The insertion of cannulae (by definition, a needle with a lumen) or angiocaths into a vascular vessel.
Buttonhole technique or constant-site technique: The repeated cannulation into the exact same puncture site so that a scar tissue tunnel track develops. The scar tissue tunnel track allows the needle to pass through to the outflow vessel of the fistula following the same path with each cannulation time. Only used in fistulae. Should not be used for accessing grafts.
Catheter: A device providing access to the central veins or right atrium, permitting high-volume flow rates.
Exit site: The location on the skin that the catheter exits through the skin surface.
Insertion site: Location at which the catheter enters the vein, for example, the right internal jugular vein is the preferred insertion site.
Long-term catheter: Also known as tunneled cuffed catheter (TCC); a device intended for use for longer than 1 week that typically is tunneled and has a cuff to promote fibrous ingrowth to prevent catheter migration and accidental withdrawal.
Port catheter system: Subcutaneous device for hemodialysis access that is cannulated with needles; the device contains a ball-valve system that is connected to 1 or more central venous catheters (CVCs).
Short-term catheter: A device intended for short-term use (<1 week) that typically is not tunneled. Intended for use in hospitalized patients; not for outpatient maintenance dialysis.
Diagnostic testing: Specialized testing that is prompted by some abnormality or other medical indication and that is undertaken to diagnose the cause of the vascular access dysfunction.
Dialysance: The number of milliliters of blood completely cleared of any substance by an artificial kidney or by peritoneal dialysis in a unit of time, usually a minute, with a specified concentration gradient.
Distal revascularization—interval ligation (DRIL): A surgical procedure to reduce ischemia to the hand caused by steal syndrome.
Elastic recoil: The recurrence of stenosis following angioplasty.
Fistula (plural, fistulae): Autogenous autologous arteriovenous fistula, also referred to as native.
Brescia-Cimino (radiocephalic) fistula: An autologous fistula constructed between the radial artery and the cephalic vein at the wrist.
Gracz fistula: An autologous fistula constructed between the brachial artery and a branch of the medial antecubital vein, the perforating vein, below the elbow.
Snuff-box fistula: An autologous fistula constructed between a branch of the radial artery and an adjacent vein in the anatomic snuff box of the hand.
Fistula maturation: The process by which a fistula becomes suitable for cannulation.
Rule of 6s: A fistula in general must be a minimum of 6 mm in diameter with discernable margins when a tourniquet is in place, less than 6 mm deep, have a blood flow greater than 600 mL/min, and should be evaluated for nonmaturation if, after 6 weeks from surgical creation, it does not meet these criteria.
Flow: The amount of blood flowing through a system.
QA: Access blood flow.
Qf: Ultrafiltration rate.
QB: Blood pump flow delivered to the dialyzer.
Flow measurement methods:
Crit line: Using changes in hematocrit (Hct) induced by ultrafiltration.
GPT: Glucose pump (infusion) technique.
HDM: Hemodialysis monitor using magnetic detection of differential conductivity.
Ionic dialysance: A method that uses a change in dialysis fluid sodium concentration to calculate flow.
ORX: Optodilutional recirculation measurement technique.
TD: Thermal dilution method.
TQA: Direct transcutaneous optodilutional flow method.
UDT: Ultrasound dilution technique.
VFDU: Variable flow Doppler ultrasound.
Graft: A conduit of synthetic or biological material connecting artery to vein.
Synthetic: Made of plastic polymers, such as polytetrafluoroethylene (PTFE), polyurethane (PU).
Biological: Made of biological materials, such as bovine carotid artery, cryopreserved human femoral veins, etc.
Tapered: Grafts for which internal diameter varies from the arterial to the venous end.
Untapered: Grafts with a uniform diameter, usually 6 mm.
Kt/V: A dimensionless quantity that assesses the amount of dialysis delivered.
Monitoring: The evaluation of the vascular access by means of physical examination to detect physical signs that suggest the presence of dysfunction.
Magnetic resonance angiography (MRA): A technique to visualize the arterial and venous systems using gadolinium as the imaging agent.
Neointimal hyperplasia: The myoendothelial proliferation of cells and matrix that produces stenosis, primarily in grafts.
Online: The conductance of a test during a hemodialysis procedure.
Physical examination (of the access): Inspection, palpation, and auscultation of the access.
Pressure: Force applied uniformly over a surface, measured as force per unit of area; stress or force acting in any direction against resistance.
Mean arterial pressure (MAP): Usually recorded in the arm opposite the vascular access.
PIA: Pressure in the access when there is no external blood flow for dialysis, also referred to as the “static pressure.”
Venous drip chamber pressure (VDP): Also referred as dynamic venous pressure (DVP). Measured in the venous tubing and equal to the pressure required to infuse blood back into the vascular access at the blood pump flow set.
Recirculation: The return of dialyzed blood to the systemic circulation without full equilibration.
Cardiopulmonary recirculation: Resulting from the return of dialyzed blood without full equilibration with all systemic venous return.
Access recirculation: Resulting from the admixture of dialyzed blood with arterial access blood without equilibration with the systemic arterial circulation. Occurs under conditions in which blood pump flow is greater than access flow.
Receiver operating characteristic (ROC) curve: A technique to evaluate the sensitivity and specificity of a diagnostic test to detect/predict the presence of a disease state.
Steal syndrome: Signs and symptoms (pain, coldness, cyanosis, necrosis) produced by an access as a result of the diversion of arterial blood flow into the fistula.
Acronecrosis: Gangrene occurring in the distal part of the extremities, usually fingertips and toes.
Stenosis: A constriction or narrowing of a duct or passage; a stricture.
Cephalic arch stenosis: A common site for stenosis of the cephalic vein at an anatomic site where there is a narrowing of the cephalic vein as it arches over the shoulder in the region of the deltopectoral groove before the vein junction with the axillary vein.
Surveillance: The periodic evaluation of the vascular access by means of tests, which may involve special instrumentation and for which an abnormal test result suggests the presence of dysfunction.
Tissue plasminogen activator (tPA): A natural lytic used to dissolve fibrin or nonorganized thrombus.
Transposition: The movement of a vein from its normal position either by elevation to bring the vein closer to the skin or laterally to permit easier cannulation.
Ultrasound: The use of ultrasonic waves for diagnostic or therapeutic purposes, specifically to image an internal body structure.
Doppler ultrasound (DU): Ultrasound that uses the Doppler effect to measure movement or flow in the body and especially blood flow; also referred to as Doppler ultrasonography.
Duplex Doppler ultrasound (DDU): Combines Doppler and B-mode (grayscale) imaging to provide diagnostic ultrasound used for quantitative color velocity imaging, also referred to as Doppler sonography.
Systolic velocity ratio (SVR): The ratio of velocity in an abnormal vessel relative to a normal vessel.
Urokinase: A natural lytic used to dissolve fibrin or nonorganized thrombus.
Vascular access team (VAT): Patient and group of professionals involved in management of vascular access (includes caregivers who construct, cannulate, monitor, detect problems in, and repair vascular accesses). Caregivers include nephrologist, nephrology nurse, patient care technician, nurse practitioner, physician assistant, interventionalist, surgeons, and vascular access coordinator.