PALMAZ STENT IN THE TREATMENT OF CENTRAL VENOUS STENOSIS - SAFETY ANDEFFICACY OF REDILATION

PURPOSE: To assess the safety and efficacy of redilation of central ve nous stents in a growing animal model. MATERIALS AND METHODS: Palmaz s tents were placed in the inferior vena cava (IVC) in 18 newborn lambs. After 5 months, vena cavography was performed. Those animals in which growth of the IVC adjacent to the stent and/or neointimal hyperplasia had resulted in a stenosis were considered candidates for redilation. Repeat vena cavography,intravascular ultrasound, and histologic exami nation were performed at 2 or 6 months. RESULTS: A stenosis of > 20% w as demonstrated in 13 animals. Redilation was performed, and a 50% mea n increase in stent diameter was achieved. There were no immediate com plications. Late complications included nonocclusive laminar clot (n = 2), and a bar of tissue dividing but not occluding the caval lumen (n = 1). Moderate neointimal hyperplasia occurred in all stents. Stent c ompression (unrelated to redilation) occurred in seven animals. CONCLU SION: Palmaz stents can be redilated safely and effectively in an anim al model of growing central veins.