HEALIONICS CORPORATION — Department of Health and Human Services SBIR Phase I: 400

Description

Infection Resistant Hemodialysis Access Graft vPROJECT SUMMARY ObjectiveThe objective of this Phase I SBIR project is to validate a new synthetic vascular graft construction designed toreduce infection failures of arteriovenousAVgraftsBuilding upon a previously demonstrated approach for preventingvenous end stenosisvia suppression of perigraft fibrotic encapsulationthe new design includes features that enhancethe effectiveness of the body s natural immune defenses against device associated infectionsA successful outcome willverify this design s capability to address both of the major causes of AV graft failurestenosis and infectionSignificanceEstablishing and maintaining vascular access for hemodialysis patients is extremely challengingAs a resultof slow maturation times and maturation failures in autogenous arteriovenous fistulasthe preferred vascular accessoptionand a reluctance to use synthetic AV graftsthe next safest alternativedue to infection concerns and poorpatencymore than half of all first year patientsand more thanlonger termare treated vialast resortinfectionprone cathetersThere is a desperate need for an improved AV graft to reduce reliance on cathetersInnovationHealionicsSTARgraft AVis a new way to address the AV graft infection problemFeaturing a microporoussheath with tightly controlled pore geometrym spherical pores interconnected bym openingsplaced overthe exterior of a conventional ePTFE graftthe new device is designed to combat infection via multiple mechanismsImmune cell accessible surface area within the pore space is maximizedconcentrating favorably activatedprotective macrophagesThe pore structure and surrounding tissue become permanently vascularized and fibrotic encapsulation issuppressedenabling phagocytic immune cells to migrate freelyRemarkablythe high concentration of immune cells and unimpeded cell migration within the protective sheathlayer has been shown to provide aHalo Effectinfusing the pore spaces of the inner ePTFE core layer withprotective immune cellsThis effect appears to further reduce infection vulnerability by accelerating fibrotic tissuerepair within the holes of the graft wall after needle puncturesApproachPerformance of the new AV graft will be evaluated in an established sheep modeladapted to allow bacterialchallenges via repeated mock dialysis sessionsi ecannulation with large needlesThe specific aim is to demonstratesuperior infection controli ea reduced level of bacterial colonizationcompared to conventional graftsImpactA new AV graft that reliably avoids stenosis and infection problems would provide a much improved vascularaccess option and improved quality of life for a large segment of the dialysis patient populationespecially by reducinghospitalizations and mortality due to catheter related bloodstream infectionsFull development would also have anenormous collateral economic benefiteven areduction in access related severe infections would save more than$ B annually to the health care system NARRATIVE Of the nearlyend stage renal diseaseESRDpatients on hemodialysis in the USnearlyrely on vascular access via an implanted synthetic arteriovenous graftAVGThese devices have infection rates as high asper patient yearWe have discovered that our structured porous biomaterial applied as an outer layer on conventional grafts may enhance the natural immune response to infections caused by the repeated cannulations needed for dialysisThis project will validate the infectionresistant modified AV graft in a preclinical animal studyv