title: Respiration-induced kidney motion on cobalt-chromium stent fatigue resistance.
abstract: During normal breathing, the kidneys move up and down due to the diaphragm motion and the renal artery subsequently experiences bending at or close to its point of fixation to the aorta. The impact of this kidney motion on implanted stent fatigue performance was not well understood in the past. Previous study from the authors on an 18-mm long single cobalt-chromium stent showed that the change in bending angle was minor during simulated respiration-induced kidney motion on cadavers. Finite Element Analysis revealed excellent fatigue resistance of the studied cobalt-chromium stent under simulated respiratory motion for the single stent configuration. In this article, the study was extended further to the overlapped stent configuration where a physician deploys two stents overlapping at the stent ends to fully cover a long lesion. Fluoroscopic images showed that the change in bending angle during simulated respiration-induced kidney motion on cadavers was more significant when two cobalt-chromium stents were overlapped. Calculated data of the Goodman analysis for the overlapped stents migrated toward the Goodman diagram failure line, indicating lower fatigue resistance during respiration when compared to a single stent.
authors.affiliation: Abbott Laboratories, Abbott Vascular, Santa Clara, California 95054.
authors.forename: Hao-Ming
authors.initials: HM
authors.lastname: Hsiao
authors.affiliation: Abbott Laboratories, Abbott Vascular, Santa Clara, California 95054.
authors.forename: Alexander
authors.initials: A
authors.lastname: Nikanorov
authors.affiliation: Abbott Laboratories, Abbott Vascular, Santa Clara, California 95054.
authors.forename: Santosh
authors.initials: S
authors.lastname: Prabhu
authors.affiliation: St. Joseph Vascular Institute, Orange, California 92868.
authors.forename: Mahmood K
authors.initials: MK
authors.lastname: Razavi
mesh_terms: D000465:Algorithms; D002102:Cadaver; D002857:Chromium; D003035:Cobalt; D004867:Equipment Design; D004868:Equipment Failure; D020342:Finite Element Analysis; D005471:Fluoroscopy; D006801:Humans; D007668:Kidney / Q000502:physiology*; D008422:Materials Testing; D012079:Renal Circulation / Q000502:physiology; D015656:Respiratory Mechanics / Q000502:physiology*; D012187:Retroperitoneal Space / Q000502:physiology; D015607:Stents
chemical_list: D002857:Chromium; D003035:Cobalt