Improving vascular access by reducing surgical stenosis

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ACCESS 2 Clinical Trial logo
Image of a patient's arm hooked up to hemodialysis tubes.
3.4 million patients are on dialysis globally, while 35 million suffer from chronic kidney disease.
Hemodialysis patients require treatment 3 times a week.

A functional, lasting vascular access with good blood flow is the lifeline for hemodialysis patients

there are currently three access options for hemodialysis:

Animated image of an AV graft in a patient forearm.

To create an arteriovenous graft, one end of a synthetic (usually PTFE) graft is anastomosed to an artery and the other end is anastomosed to a vein. Approximately 3-4 weeks post-surgery, the PTFE graft can be cannulated for hemodialysis. Although AV grafts offer an alternative to fistula for patients with small or weak veins, it increases the risk of blood clotting, aneurysms, and infections.

Animated image of a CVC catheter with a neck access.

Today in the U.S., approximately 80% of incident patients begin dialysis using a central venous catheter (CVC), the least preferred option. These patients will continue to be dialyzed using a catheter until a mature AV fistula or an AV graft is ready for insertion of needles to support dialysis. The use of catheters is associated with serious mortality and morbidity events that include infection, thrombosis and stenosis or occlusion of the central vein.

Stenosis is a major problem that threatens access

For AV fistula and av Grafts

Animated image of an AV fistula affected by stenosis, narrowing the fistula access.
Pie chart showing 50% failure rate in AV fistulae and grafts within 6-12 months.

UP TO 50% OF FISTULA require additional procedures or fail within 6-12 months

The failure is due primarily to a narrowing (stenosis) at the anastomosis and/or vein as a result of intimal hyperplasia.

[Ref: The Dialysis Access Consortium Studies (DAC)]

Sirogen™ is designed to prevent stenosis and ensure blood flow to support consistent dialysis

Animated image of an AV fistula wrapped in Sirogen™.
Sirogen™ completely wrapped around the anastomosis site.

Designed to maintain its cylindrical shape without the need for sutures and permit the expected increase in vein diameter

Sirogen™ completely wrapped around the anastomosis site.

A novel bioresorbable collagen-based drug delivery system

Close-up image depicting the release and delivery of Sirolimus from Sirogen™ onto the anastomosis site.

Applies a well-studied drug (sirolimus) to the blood vessel at and around the anastomosis which has been shown clinically to suppress the formation intimal hyperplasia


Sirogen™ is a bioabsorbable implant that delivers a well-known drug called sirolimus to blood vessels. Sirolimus has been shown to keep blood vessels open. It is used in kidney transplant patients and with vascular devices to reduce blood vessel narrowing. During surgery to create the fistula, Sirogen™ is applied at the area of the fistula that is prone to narrowing.

The ACCESS 2 clinical study for patients 65 and older is determining if Sirogen can:

Increase the proportion of fistula that can be used for successful hemodialysis

Reduce the time between surgical creation of the fistula and when it can be used for hemodialysis

Reduce the proportion of fistula that are abandoned and require a new access

Achieving these endpoints is expected to reduce catheter dwell time and catheter dependence – a much-desired outcome with important implications for patients, dialysis providers, and payors.

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ACCESS 2 Clinical Study