What are the types of dialysis catheters?

Types of Dialysis Catheters

Dialysis catheters are classified into two main categories: non-tunneled (short-term) catheters and tunneled (long-term) catheters, each designed for specific clinical scenarios and duration of use. 1

Non-Tunneled (Short-Term) Catheters

• Uncuffed hemodialysis catheters should only be used in hospitalized patients and for less than 1 week 1
• Uncuffed femoral catheters should only be used in bed-bound patients 1, 2
• Short-term catheter tips should be positioned in the superior vena cava and confirmed by chest radiograph or fluoroscopy 1
• Most acute catheters are made of polyurethane, though silicone catheters are available with larger lumen sizes capable of delivering blood flow rates over 300 ml/min 2
• There should always be a plan to either discontinue or convert any short-term catheter to a long-term catheter within 1 week 1

Tunneled (Long-Term) Catheters

• Tunneled cuffed catheters (TCCs) are intended for use longer than 1 week and typically have a cuff to promote fibrous ingrowth to prevent catheter migration 1
• Long-term catheter tips should be positioned within the right atrium for optimal flow, confirmed by fluoroscopy 1
• Catheters capable of rapid blood flow rates (350 mL/min at prepump pressures not more negative than 250 mm Hg) are preferred 1
• Most commonly feature a "double D" lumen design, though some have staggered tips or split tips to prevent recirculation 1
• Newer designs incorporate spiral separators allowing either lumen to be used as the arterial port 1

Port Catheter Systems

• Subcutaneous devices for hemodialysis access that are cannulated with needles 1
• Contain a ball-valve system connected to one or more central venous catheters 1
• Access to the catheter lumen occurs percutaneously using a buttonhole technique 1
• May be used in lieu of long-term catheters as a bridge access or as permanent access 1

Materials and Design Considerations

• Polytetrafluoroethylene (Teflon) or polyurethane catheters have been associated with fewer infectious complications than catheters made of polyvinyl chloride or polyethylene 1
• Antimicrobial-coated catheters (minocycline and rifampin) have shown reduced risk of catheter-related bloodstream infections 1, 3
• Silicone is more compatible with infusates but more prone to compression, while polyurethane is tougher but more susceptible to degradation by drug solvents 3

Preferred Insertion Sites

• Right internal jugular vein is the preferred insertion site 1, 3
• Femoral vein is the second choice, particularly for acute temporary access 3
• Left jugular vein is the third choice 3
• Subclavian vein should be avoided when possible due to risk of central venous stenosis 3

Advantages of Tunneled Cuffed Catheters

• Universal applicability 1
• Can be inserted into multiple sites relatively easily 1
• No maturation time needed - can be used immediately 1
• No skin puncture required for repeated vascular access 1
• Lower initial costs compared to other access types 1
• Ability to provide access during periods of fistula maturation 1

Disadvantages and Complications

• Higher morbidity due to thrombosis and infection compared to arteriovenous fistulae or grafts 1, 4
• Risk for permanent central venous stenosis or occlusion 1
• Discomfort and cosmetic disadvantage of an external appliance 1
• Shorter expected use-life than other access types 1
• Overall lower blood flow rates, requiring longer dialysis times 1
• Common complications include central venous stenosis (33.4%), catheter-related infections (29.6%), displacement (27.8%), and thrombosis (7.9%) 5

Important Clinical Considerations

• Ultrasound guidance should be used for all dialysis catheter insertions 3
• Long-term catheters should not be placed on the same side as a maturing arteriovenous access 1, 3
• Femoral catheters should be of sufficient length (24-31 cm) to reach the inferior vena cava to deliver adequate blood flow 1
• Prolonged catheter use is associated with increased mortality (51% increase) and severe infection (130% increase) compared to arteriovenous fistulae or grafts 3
• Despite complications, tunneled catheters may be necessary for patients with failed arteriovenous access (34%), nonmaturing arteriovenous access (32%), or no arteriovenous access options (10%) 5