Clinical Overview

The vascular access has been called the Achilles Heel of dialysis patients because every quality of care indicator assumes a patent access, ideally one that is an arteriovenous (AV) graft or fistula. However, the care and maintenance of the access has always been a challenge. The difficulty has been to find an effective and efficient way to determine when a patient is ‘at risk for clotting’ so that they can be referred in a timely manner for proactive intervention.

The Clinical Challenge  – The whole idea behind vascular access management is the prevention of thrombosis. When an access clots, nothing good happens:

  • Increased hospitalization – a significant number of HD patients are admitted due to access complications.
  • Thrombectomies are expensive, painful for the patient, and are often unsuccessful.
  • Catheter insertions often result, leading to decreased dialysis efficiency and increased chance of infection.
  • Thrombosis and the resulting complications are the main reason for the loss of AV accesses.

While every AV access will eventually fail, the early detection and treatment of stenosis can reduce the advent of access complications due to thrombosis. At any given time, 19% of catheter patients are on a permanent catheter due to loss of all AV access sites and another 12% are on a catheter due to access complications[1]. The ultimate benefit of vascular access management is the reduction of thrombosis and extension of access life[2].

Surveillance Done Right  – The first line of defense against stenosis is a good surveillance device. Vasc-Alert is the ideal medical device to test for stenosis because:

  • It tests the access during each treatment so even a rapidly growing stenosis can be detected.
  • The frequency of testing allows the observation of trends, i.e. how fast is the stenosis growing?clinical overview surveillance report
  • The self-documenting record provides medical staff the ability to correlate past access events with current results, improving diagnosis and providing a basis for making timely referrals.
  • The presentation of test results is a simple, intuitive graph, so even a non-compliant patient can understand the need for intervention.
  • The efficacy of the Vasc-Alert device is very high, with sensitivity and specificity in the 85% to 95% range and very low false positive rates.
  • Vasc-Alert is an early indicator of stenosis, typically allowing for interventions in the 60% to 70% range, which translates to better outcomes.

Beyond Surveillance 101  – Vasc-Alert also provides an analytical basis for the managed care of the vascular access. Beyond detecting stenosis, the weekly reports allow case managers to:

  • Improve the survival of new fistulas once cannulation begins by identifying those not maturing well.
  • Help determine when an access is nearing the end of its effective life so that a new AV access can be placed, thus decreasing the need for a bridge catheter.
  • If the patient is on his last AV access, special attention can be focused to maintaining patency in order to forego the placement of a permanent catheter.
  • Post-intervention assessments can be made as to how effective an intervention was in opening the occlusion.


[1] Clinical Performance Measures, 2007. A study conducted by CMS

[2] A five-year RCT study published by Nicola Tessitore in JASN in 2003 indicated the average life of a fistula in the control group was 21 months, in the treatment group (with surveillance) the average age was 84 months.