Structured Abstract:
Introduction: Cardiac implantable electronic devices (CIEDs)
induce a foreign body reaction and persistent inflammatory response that
produces a fibrotic capsule around the implanted material. The study’s
aim was to investigate the ability of small intestinal submucosa (SIS)
extracellular matrix (ECM) envelopes to mitigate fibrotic tissue
formation and secure devices within healthy, vascularized tissue.
Methods: Clinically relevant pacemakers without leads were
subcutaneously implanted in a pre-clinical rabbit model. Eleven CIEDs
were placed in CanGaroo ECM Envelopes, while ten devices were implanted
without envelopes and analyzed at 13 and 26 weeks. The subcutaneous
pocket and newly formed connective tissue adjacent to the CIED were
evaluated by an independent, blinded pathologist for the local tissue
response and constructive remodeling. CIED movement in the pocket was
also documented as implant sites were prone to abrasion due to normal
rabbit behavior.
Results: CanGaroo Envelopes surrounding the CIEDs remodeled into
native tissue with normally organized collagen. The tissue had a lower
average thickness at 13 and 26 weeks compared to tissue encapsulating
CIEDs without envelopes. The tissue also scored significantly higher in
neovascularization versus capsule tissue surrounding CIEDs without
envelopes at 26 weeks. Use of the ECM envelope reduced the incidence of
device flipping within the pocket by 40% compared to CIEDs without
envelopes, showing the ability of CanGaroo Envelopes to secure CIEDs in
place.
Conclusions: CanGaroo ECM Envelopes remodeled into native,
vascularized tissue surrounding clinically applicable CIEDs. This
thinner, healthy tissue pocket secured CIEDs and significantly improved
stabilization versus devices without envelopes over 26 weeks.