Pseudointima in inflow conduits of left ventricular assist devices.
BACKGROUND
Explant analysis of left ventricular assist systems (LVAS) should permit a better evaluation of long-term evolution of materials and tissue healing in patients supported by mechanical devices and a precise understanding of embolic phenomena, observed clinically.


METHODS
Five Novacor LVAS and their conduits have been explanted after 156 days (range 61-226 days) of mechanical support. The pseudo-intima (PI) developed in the inflow and outflow conduits was characterized microscopically, using monoclonal antibodies.


RESULTS
The morphological aspects of PI were quite different in the inflow and outflow conduits. Blood coagulation between the basal surface of the PI and the Dacron tube, irregular collagen type I matrix with plasma infiltration, macrophages, and neutrophil granulocyte elastase characterized the nonadherent, loose, and potentially thrombogenic PI growth in the inflow conduit. The PI from collagen types I and IV with circumferentially oriented alpha-smooth muscle cell actin-positive cells was anchored to the outflow conduits.


CONCLUSIONS
The observations, which have to be confirmed by a more extensive study on a larger number of specimens, suggest the role of the biomaterial itself, as well as the configuration, physical characteristics, and rheology in the conduit. They also suggest that thromboembolic complications of LVAS may eventually be related to this host tissue response.
Houel
R
R
Department of Cardiothoracic and Cardiovascular Surgery, Hôpital Henri Mondor, Créteil, France.
Moczar
M
M
Clerin
V
V
Loisance
D Y
DY
D000293:Adolescent; D000328:Adult; D001777:Blood Coagulation / Q000502:physiology; D001807:Blood Vessel Prosthesis; D002452:Cell Count; D003094:Collagen / Q000378:metabolism; D004617:Embolism / Q000473:pathology; D005260:Female; D005337:Fibrin / Q000378:metabolism; D006353:Heart-Assist Devices; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D011093:Polyethylene Terephthalates; D011474:Prosthesis Design; D012212:Rheology; D012770:Shock, Cardiogenic / Q000473:pathology / Q000601:surgery*; D017539:Tunica Intima / Q000473:pathology*; D014945:Wound Healing / Q000502:physiology
D011093:Polyethylene Terephthalates; D005337:Fibrin; D003094:Collagen