Impact on Pulmonary Arterial Pressures after Repeated Endovascular Thrombectomy of Dialysis Grafts: A Prospective Follow-up Study

Recurrent thrombosis and patency of the arteriovenous access in patients receiving hemodialysis

BACKGROUND

Thrombosis of the vascular access in patients with end-stage renal disease requiring hemodialysis are common and require timely interventional procedures to restore patency. The aim of the current study was to identify factors having a significant effect on patency rates after access thrombosis. Our hypothesis was the length of time between the initial clotting of the access and the subsequent percutaneous declotting impacts the patency rates of the vascular access.

METHODS

In this retrospective cohort study, patients with a clotted arteriovenous access between Jan 1, 2011, and Jan 1, 2016, were included. Demographics, access history, and associated details of the access procedure were reviewed from the electronic medical record. Statistical analysis was done using t-test and chi-square or fisher exact tests to compare arteriovenous fistulae (AVF) and arteriovenous grafts (AVG). Primary patency, defined as the time from index procedure to endpoint, was analyzed using the Kaplan-Meier method and log rank test.

RESULTS

There were 883 percutaneous declotting procedures reviewed. About 351 procedures were performed in patients with an AVF and 532 with an AVG. The mean time from thrombosis to declotting was 1.71 ± 2.29 days. The overall median primary patency for both AVF and AVG was 43 days with no difference in patency between patients with AVF (39 days) versus AVG (42 days; p = 0.385). The time period from access thrombosis to declotting did not affect patency rates for either AVG or AVF (p = 0.385). On multivariable analysis, prior intervention (HR: 1.32, 95% CI: 1.14-1.53, p < 0.001) and cardiovascular disease (HR: 1.19, 95% CI: 1.03-1.37, p = 0.016) were independently associated with access patency.

CONCLUSIONS

Time from thrombosis to declotting did not affect patency rates however once there was a thrombotic event, recurrent thrombosis requiring intervention was common with patency significantly decreased. Future prospective studies to validate our results and study pathogenic mechanisms of recurrent thrombosis are warranted.

Complications in Percutaneous Dialysis Interventions: How to Avoid Them, and How to Treat Them When They do Occur

Because of the increasing prevalence of end-stage renal disease, more percutaneous interventions are being performed. They serve an important role, allowing for restoration of access function, which is achieved with high level of technical success. However, complications are inevitable during any types of procedure, and percutaneous dialysis interventions are no exception. To provide safe and effective care these patients need, anyone performing endovascular dialysis interventions needs to understand the possible complications, how they can be avoided, and how they can be addressed if they are to occur. Topics in this article include complications seen while intervening on the thrombosed access, complications of angioplasty, potentially devastating complications of central venous interventions, and complications of dialysis catheter placement. Further, patients with end-stage renal disease are generally sicker than the average patient, usually afflicted by multiple comorbidities and are therefore more complicated from a medical perspective. This places them at higher risk for acute cardiopulmonary decompensation or arrest than any other interventional radiology patient subset. As result, we also briefly review general medical complications in this population.