What are the success rates and potential risks of using a Permacath (permanent catheter) for long-term dialysis in patients with Impaired renal function?

Permcath Success Rates and Risks for Long-Term Hemodialysis

Permcaths (tunneled cuffed catheters) should be avoided as permanent dialysis access whenever possible due to significantly higher mortality, infection rates, and lower blood flow rates compared to arteriovenous fistulas. 1

Success Rates

• Initial technical success rates for Permcath placement are high (approximately 95-98%) when placed under ultrasound guidance 2
• Functional patency rates:
  • 81.6% of patients have no complications within three months of placement 3
  • Approximately 72% secondary patency rate at one year 4
  • Primary patency rates are lower (around 53%) due to complications requiring intervention 4

Major Risks and Complications

Infection

• Systemic and local infections occur significantly more frequently with cuffed catheters than with AV fistulas 1
• Infection rates requiring catheter removal range from 2.2-6.5% 2, 3
• Catheter-related bloodstream infections can lead to septicemia, with mortality rates of approximately 3.3% within one week of infection 2

Thrombosis

• Thrombosis rates range from 4.4% 3 to higher rates depending on placement site and patient factors
• Fibrin sheath formation occurs in up to 76% of catheters, potentially requiring intervention 1
• The recommended thrombosis rate should not exceed 0.5 thrombotic episodes per patient-year 1

Inadequate Blood Flow

• Cuffed catheters are associated with lower blood flow rates compared to AV access 1
• Inadequate flow rates occur in approximately 6.5% of cases 2
• Lower flow rates can compromise dialysis adequacy, leading to increased morbidity and mortality 1

Central Venous Stenosis

• Long-term catheter use is associated with central venous stenosis 1, 5
• This complication can preclude future establishment of permanent vascular access in the affected limb 5
• Subclavian vein placement carries the highest risk of stenosis and should be avoided 5

Procedural Complications

• Vascular injury during insertion (2.2% risk of vessel tear with potential for severe complications) 2
• Cardiac arrhythmias, pneumothorax, hemothorax, and arterial puncture
• Malposition requiring repositioning

Placement Considerations

1. Preferred insertion site: Right internal jugular vein (offers most direct route to right atrium with lowest complication rates) 5
2. Alternative sites (in order of preference):
   • Left internal jugular vein (27.2% of placements) 2
   • Femoral vein (13% of placements) - only for bed-bound patients or when other sites unavailable 5, 2
   • External jugular vein - can be a safe alternative when internal jugular access is not possible 3
   • Avoid subclavian vein due to high risk of central venous stenosis 5

Guidelines for Permcath Use

According to the National Kidney Foundation KDOQI guidelines, Permcaths should be limited to specific situations:

1. Temporary bridging access while awaiting AV fistula maturation 1
2. Last resort permanent access only when:
   • Multiple prior failed AV accesses with no feasible options remain
   • Patient has valid preference after informed consent
   • No viable options due to vascular problems 1

The KDOQI guidelines recommend that less than 10% of chronic maintenance hemodialysis patients should be maintained on catheters as permanent access 1.

Mortality Impact

Mortality is 2.2 times higher for patients who remain on hemodialysis catheters compared to those using arteriovenous fistulas 1, 5. Absolute all-cause mortality rates:

• 29.5% for AV fistulas
• 36.7% for prosthetic grafts
• 42.2% for patients persistently dialyzing through catheters 1

Appropriate Indications for Permcath

Permcaths are appropriate in the following scenarios:

• Bridge to AV fistula maturation (14.1% of cases) 2
• Bridge to kidney transplantation (19.6% of cases) 2
• Patients with short life expectancy 6
• Patients with no viable options for permanent access creation 6

Conclusion

While Permcaths provide immediate vascular access for hemodialysis with high technical success rates, they should not be considered the first choice for long-term dialysis access due to higher complication rates and mortality compared to AV fistulas. Their use should be limited to temporary bridging or specific situations where other access options are not feasible.