Surgical resection and graft replacement for primary inferior vena cava leiomyosarcoma: A multicenter experience: Accepted for presentation at the 2020 Vascular Annual Meeting of the Society for Vascular Surgery, Toronto, Ontario, Canada, June 17-20, 2020 (conference cancelled). Presented at the 2020 Society for Vascular Surgery ONLINE, June 20-July 31, 2020.