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

• Published in: International angiology Vol. 23; no. 2; pp. 170 - 176
• Main Authors: YOSHIDA, W. B, SEQUERA, J, DE ABREU MAFFEI, F. H
• Format: Journal Article
• Language: English
• Published: Torino Minerva Medica 01.06.2004; Edizioni Minerva Medica
• Subjects: Alcoholism and acute alcohol poisoning; Animals; Biocompatible Materials; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cardiovascular system; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Female; Male; Medical sciences; Microscopy, Electron, Scanning; Pharmacology. Drug treatments; Prosthesis Design; Sheep; Toxicology; Vascular Patency; Vasodilator agents. Cerebral vasodilators; Vena Cava Filters; Vena Cava, Inferior - pathology; Vena cava, inferior; Respiratory disease; Cardiovascular disease; Experimental study; Vascular disease; Pulmonary embolism; Vertebrata; Anatomic pathology; Mammalia; Filter; Sheep; Artiodactyla; Ungulata; Inferior vena cava
• ISSN: 0392-9590; 1827-1839

The authors assess a modified Greenfield filter (GF) for the long-term patency, filter tilting and histopathologic alterations of the inferior vena cava (IVC). 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. 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. 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.