title: Results of a multicenter study of the modified hook-titanium Greenfield filter.
abstract: Initial efforts to modify the stainless steel Greenfield filter for percutaneous insertion led to development of a titanium Greenfield filter, which could be inserted by use of a 12F carrier. This device functioned well as a filter but had an unacceptable 30% rate of migration, tilting, and penetration. Therefore a titanium Greenfield filter with modified hooks was developed and has been tested in 186 patients at 10 institutions. Successful placement occurred in 181 (97%); placement of the remainder was precluded by unfavorable anatomy. A contraindication to anticoagulation was the most frequent indication for insertion (75%). All but two were inserted percutaneously, predominantly via the right femoral vein (70%). Initial incomplete opening was seen in four patients (2%), which was corrected by guide wire manipulation and asymmetry of the legs in 10 (5.4%). Insertion site hematoma occurred in one patient, and apical penetration of the cava during insertion occurred in a second patient. Both events were without sequelae. Follow-up examinations were performed at 30 days at which time 35 deaths had occurred. Recurrent embolism was suspected in six patients (3%) and two of three deaths were confirmed by autopsy. Filter movement greater than 9 mm was seen in 13 patients, (11%) and increase in base diameter greater than or equal to 5 mm was seen in 17 patients (14%). CT scanning showed evidence of caval penetration in only one patient (0.8%). Insertion site venous thrombosis was seen in 4/46 (8.7%) patients screened. The modified hook titanium Greenfield filter is inserted percutaneously or operatively through a sheath, eliminating concern for misplacement from premature discharge.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: University of Michigan, Ann Arbor.
authors.forename: L J
authors.initials: LJ
authors.lastname: Greenfield
authors.forename: K J
authors.initials: KJ
authors.lastname: Cho
authors.forename: M
authors.initials: M
authors.lastname: Proctor
authors.forename: J
authors.initials: J
authors.lastname: Bonn
authors.forename: J J
authors.initials: JJ
authors.lastname: Bookstein
authors.forename: W R
authors.initials: WR
authors.lastname: Castaneda-Zuniga
authors.forename: B
authors.initials: B
authors.lastname: Cutler
authors.forename: E J
authors.initials: EJ
authors.lastname: Ferris
authors.forename: F
authors.initials: F
authors.lastname: Keller
authors.forename: T
authors.initials: T
authors.lastname: McCowan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002406:Catheterization, Peripheral / Q000295:instrumentation; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013499:Surface Properties; D015996:Survival Rate; D013923:Thromboembolism / Q000517:prevention & control; D014025:Titanium; D014481:United States / Q000453:epidemiology; D016306:Vena Cava Filters / Q000706:statistics & numerical data*; D014682:Vena Cava, Inferior
chemical_list: D014025:Titanium