The DENALI Trial: an interim analysis of a prospective, multicenter study of the Denali retrievable inferior vena cava filter.
S William Stavropoulos, Ronald F Sing, Fakhir Elmasri, Mitchell J Silver, Alex Powell, Frank C Lynch, Ahmed Kamel Abdel Aal, Alexandra J Lansky, Richard A Settlage, Bart E Muhs, DENALI Trial Investigators
Author Information
S William Stavropoulos: Division of Interventional Radiology, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, 1 Silverstein, 3400 Spruce St., Philadelphia, PA 19104. Electronic address: william.stavropoulos@uphs.upenn.edu.
Ronald F Sing: Division Surgical Critical Care, Carolina's Medical Center, Charlotte, North Carolina.
Fakhir Elmasri: Division of Interventional Radiology, Lakeland Regional Medical Center, Lakeland, Florida.
Mitchell J Silver: Division of Interventional Cardiology and Peripheral Vascular Disease, Ohio Health Heart and Vascular, Riverside Methodist Hospital, Columbus, Ohio.
Alex Powell: Department of Radiology, Division of Interventional Radiology, Baptist Cardiac and Vascular Institute, Miami, Florida.
Frank C Lynch: Division of Interventional Radiology, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania.
Ahmed Kamel Abdel Aal: Division of Interventional Radiology, Department of Radiology, University of Alabama at Birmingham Medical Center, Birmingham, Alabama.
Alexandra J Lansky: Division of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut.
Richard A Settlage: C. R. Bard, Murray Hill, New Jersey.
Bart E Muhs: Section of Vascular Surgery, Department of Surgery, Yale University School of Medicine, New Haven, Connecticut.
PURPOSE: To assess safety and effectiveness of a nitinol retrievable inferior vena cava (IVC) filter in patients who require caval interruption to protect against pulmonary embolism (PE). MATERIALS AND METHODS: Two hundred patients with temporary indications for an IVC filter were enrolled in this prospective, multicenter clinical study. Patients undergoing filter implantation were to be followed for 2 years or for 30 days after filter retrieval. At the time of the present interim report, all 200 patients had been enrolled in the study, and 160 had undergone a retrieval attempt or been followed to 6 months with their filter in place. Primary study endpoints included technical and clinical success of filter placement and retrieval. Patients were also evaluated for recurrent PE, new or worsening deep vein thrombosis, and filter migration, fracture, penetration, and tilt. RESULTS: Clinical success of placement was achieved in 94.5% of patients (172 of 182), with a one-sided lower limit of the 95% confidence interval of 90.1%. Technical success rate of filter placement was 99.5%. Technical success rate of retrieval was 97.3%; 108 filters were retrieved in 111 attempts. In two cases, the filter apex could not be engaged with a snare, and one device was engaged but could not be removed. Filter retrievals occurred at a mean indwell time of 165 days (range, 5-632 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of retrieval or 6-month follow-up. CONCLUSIONS: In this interim report, the nitinol retrievable IVC filter provided protection against pulmonary embolism, and the device could be retrieved with a low rate of complications.
