ORIGINAL ARTICLES   

International Angiology 2004 June;23(2):170-6

Copyright © 2004 EDIZIONI MINERVA MEDICA

lingua: Inglese

Long-term histopathologic evaluation of inferior vena cava after modified Greenfield filter implantation. Experimental study in sheep

Yoshida W. B. ¹, Sequera J. ², De Abreau Maffei F. H. ¹

¹ Department of Surgery and Orthopedics, Botucatu School of Medicine, Botucatu, São Paulo, Brazil 2 Department of Pathology, School of Veterinary Medicine, Paulista State University, São Paulo, Brazil

Aim. The ­authors ­assess a mod­i­fied Green­field fil­ter (GF) for the long-term paten­cy, fil­ter tilt­ing and his­to­path­o­log­ic alter­a­tions of the infe­ri­or vena cava (IVC).
Meth­ods. Adult sheep (n=7) under­went mod­i­fied GF place­ment in the IVC. Cavo­grams were ­obtained every 3 ­months and pul­mo­nary angio­gra­phy at 12 ­months. His­to­path­o­log­ic and scan­ning elec­tron micros­co­py (SEM) anal­y­ses were per­formed on the IVC explant­ed at 12 ­months.
­Results. Cavo­grams ­showed that all IVC were pat­ent at the end of the study. Fil­ter tilt­ing ­occurred in 2/7 ani­mals and extru­sion of ­struts was not ­observed. Mac­ro­scop­ic exam­ina­tion at explan­ta­tion ­showed min­i­mal ­venous wall thick­en­ing. Micro­scop­ic exam­ina­tion ­showed min­i­mal IVC fibro­sis and inti­mal hyper­pla­sia. SEM ­showed endo­the­li­um on the IVC sur­face at the fil­ter implan­ta­tion site and a pre­sumed endo­the­lial layer cov­er­ing par­tial­ly or total­ly the ­struts. The inter­face fil­ter-IVC was cov­ered by depos­its of leu­coc­y­tes and plate­lets. No signs of pul­mo­nary embo­lism were found in all pul­mo­nary angio­grams of both ­groups.
Con­clu­sion. The mod­i­fied fil­ter pre­sent­ed good bio­com­pat­ibil­ity, stabil­ity and ­absence of throm­bog­e­nic­ity at 12 ­months. It pre­sent­ed low ten­den­cy to tilt­ing and extru­sion of ­struts. The long-term his­to­path­o­log­ic alter­a­tions in vena caval wall were min­i­mal and the appear­ance of the stud­ied fil­ters in the IVC was sim­i­lar to ­stents ­placed in the arte­ri­al ­system.