Early Data Show Promise of Endovascular Fistulas as Alternative to Surgical AVFs

San Francisco, CA—Early clinical data suggests that in situ catheter-based fistulas may be superior to surgical arteriovenous fistulas (AVFs) with respect to patency, need for re-intervention, and time to usability.

William E. Cohn, MD, of Texas Heart Institute at St. Luke’s Episcopal Hospital, Houston, discussed percutaneous catheter-based creation of AVFs with the FLEX EndoAVF (TVA Medical), which he said has the potential to change the way dialysis access is created. In a study comparing percutaneous vs. surgical AVF in 33 patients, early results indicate a success rate of 95% with the EndoAVF.

Surgical AVFs are operator dependent, have a failure rate of 30% to 60% and require frequent interventions to maintain functionality, Cohn said, adding that they can often take months before they are viable for use in hemodialysis. Additional study is needed, Cohn added.

“The EndoAVF may offer a lower failure rate than surgical [AVFs] and shorter maturation time than surgical AVFs,” Cohn observed. EndoAVFs are usable roughly 4 months faster than surgical AVFs, offering a 68% reduction in time to a useable fistula (179 days vs. 58 days), he noted.

 

endo.tues.29Method of implantation

The EndoAVF device uses two vascular catheters, incorporating magnets and a radiofrequency electrode, that are delivered percutaneously to an artery and vein in the arm. When the catheters are magnetically aligned and positioned via fluoroscopy, radiofrequency energy is delivered (lasting about 0.5 second) to create an AVF without open surgery. No implant is left behind. The EndoAVF is not yet approved by the FDA for use in the United States.

The preferred insertion site has not been released at present, Cohn said during his presentation. 

Compared with surgical AVFs, the technique used with endovascular AVF is safer and more reproducible. According to Cohn, by putting this technique in the hands of interventional and endovascular specialists, earlier and more frequent creation of AVF may decrease dependence on central venous catheters. 

Clinical experience

A total of 33 patients, mean age 51 years, have received this device. Sixty-one percent were male with an average BMI of 24.3. Thirty percent of patients had a BMI of 25 or greater, and 58% of patients had diabetes. 

Results indicated high rates of  technical success, fistula patency and vein maturation at 8 to 12 weeks post-procedure by both angiography and ultrasound, with few adverse events (see Figure).

Cohn concluded that there are many advantages to using endovascular-based AVF, including that non-surgical technique leaves no implant behind, so there is less risk for wound infections and complications. This procedure may also be performed in an outpatient setting. 

“This procedure has the potential to improve AVF success rates through lack of vessel trauma and surgical anastomosis,” Cohn said.


Disclosures:

Cohn reports that he is a founder and board member of TVA Medical. 

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