Elastic Flow-Control Grafts
VascX is developing elastic flow-control grafts as part of its patented platform for hemodialysis access. The concept is intended to preserve dialysis performance while reducing excessive AV graft flow and the cardiac burden that can accompany it.
The arteriovenous graft has been a workhorse of hemodialysis access for decades. It is reliable, technically straightforward to place, and gives clinicians a predictable conduit for dialysis. It also creates a low-resistance pathway between artery and vein that drives a continuous high-flow circuit through the heart — and that continuous flow is the variable VascX's elastic flow-control grafts are designed to address.
What is an elastic flow-control graft?
An elastic flow-control graft is a dialysis access graft whose internal geometry is designed to limit excessive access flow while still supporting dialysis. The "elastic" part of the description matters: the graft is intended to flex enough to accept standard access management — including cannulation needles, balloon-assisted procedures, and thrombectomy devices — and to return to its calibrated flow-control profile after those interventions.
Conceptually, this is the opposite of a stent-graft optimized for maximum patency at maximum flow. The design question is not "how much flow can the device deliver?" but "how much flow does dialysis actually need, and how much continuous extra flow can the patient's heart safely tolerate?"
Why AV graft flow matters
AV grafts are an important hemodialysis access option, especially for patients whose veins are not suitable for a fistula. But, like fistulas, AV grafts create a sustained low-resistance circuit between artery and vein, increasing venous return and cardiac output demand around the clock — not just during dialysis sessions.
Excessive AV graft flow has been associated with cardiac burden in some patients, including cardiac remodeling, pulmonary hypertension, and high-output heart failure in susceptible patients. For a deeper look at the underlying problem, see high-flow dialysis access and high-output heart failure and dialysis access.
Flow-control AV graft design
A flow-control AV graft is built around the recognition that the dialysis machine and the heart have different flow needs. The machine pulls a few hundred milliliters per minute through the dialyzer during a treatment session; everything beyond that is continuous extra flow the heart has to support. A flow-control AV graft is designed to deliver the flow needed during dialysis while limiting that continuous excess.
VascX's elastic flow-control grafts implement this design through a calibrated geometry intended to limit access flow without occluding the access. The graft is designed to be placed using standard surgical workflows for AV graft creation, so the practical change for the implanting surgeon is intended to be minimal.
Preserving dialysis adequacy
Reducing access flow only matters clinically if dialysis adequacy is preserved. A flow-control AV graft that compromised the patient's ability to receive effective hemodialysis would not be a meaningful improvement. The design intent of VascX's elastic flow-control grafts is to deliver the dialysis-machine flow needed during treatment while limiting continuous between-session access flow.
Whether a given device achieves this two-sided goal in practice is an empirical question to be answered by preclinical and clinical evidence. VascX's elastic flow-control grafts are investigational and have not yet been demonstrated in clinical use; the company makes no claim that they are proven to preserve dialysis adequacy or to reduce cardiac burden.
Cannulation and intervention compatibility
An AV graft has to be cannulated for every dialysis treatment and may need standard interventions over its lifespan. Thrombectomy in particular — the procedure used to clear clot and restore access patency — is part of the routine clinical management of grafts. A flow-control device whose geometry could not accommodate standard cannulation or thrombectomy would shift the clinical cost onto the patient and the access team.
VascX's elastic flow-control grafts are designed to support standard cannulation patterns and to accept standard interventions, including thrombectomy. The elasticity of the device is what enables this: the graft is intended to flex to accommodate a thrombectomy catheter and then return to its calibrated profile afterward, so flow-control is preserved without imposing new procedural constraints.
Part of the VascX patented platform
VascX's elastic flow-control grafts are one component of a broader patented platform for flow-control dialysis access. At the Vascular Access Society of the Americas (VASA), Dr. John Ross discussed the "VascX patented platform" and presented images of VascX's "elastic flow-control grafts" and "elastic flow-control stents." The graft and the stent are designed to address related but distinct clinical situations: a graft for new access creation where flow-control can be built in from the start, and a stent for existing high-flow AV access where flow-control needs to be introduced into the circuit.
For more on the broader category and the VASA discussion, see flow-control dialysis access and the press release VascX flow-control platform highlighted at VASA.