title: Comparison of physiological and post-endovascular aneurysm repair infrarenal blood flow.
abstract: Endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms results in redirection of blood through the deployed endograft (EG). Even though EVAR is clinically effective, the absolute flow restoration is not warranted. Our purpose was to compare the physiological with the post-EVAR infrarenal flow conditions. We developed patient-specific models based on computed tomography data of five healthy volunteers and ten patients treated with the Endurant®stent-graft system. Wall shear stress (WSS), helicity, pressure and velocity fields were calculated using computational fluid dynamics. The results showed a decrease of peak WSS on the part of the EG that resides in the iliac arteries, compared to the physiological value (p = 0.01). At the abdominal part, the average helicity seems to increase after EVAR, while at the iliac arteries part, the intensity of helical flow seems physiological. Pressure drop and peak velocity in the iliac arteries part are lower than the physiological values (p = 0.04). The comparison revealed that most hemodynamic properties converge to normal levels at the abdominal part whereas statistically significant variations were observed in the iliac arteries part. The delineation of the differences between physiological and postoperative flow data could pave the way for the improvement of EG designs.
authors.affiliation: a Department of Surgery-Vascular Surgery Unit, Medical School , University of Ioannina , Ioannina , Greece.
authors.forename: Anastasios
authors.initials: A
authors.lastname: Raptis
authors.affiliation: b Department of Mathematics , University of Ioannina , Ioannina , Greece.
authors.forename: Michalis
authors.initials: M
authors.lastname: Xenos
authors.affiliation: c Department of Vascular Surgery, Medical School , Democritus University of Thrace , Alexandroupolis , Greece.
authors.forename: Efstratios
authors.initials: E
authors.lastname: Georgakarakos
authors.affiliation: a Department of Surgery-Vascular Surgery Unit, Medical School , University of Ioannina , Ioannina , Greece.
authors.forename: George
authors.initials: G
authors.lastname: Kouvelos
authors.affiliation: d Department of Vascular Surgery, Faculty of Medicine , University of Thessaly , Larissa , Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Giannoukas
authors.affiliation: e Department of Vascular Surgery , Stony Brook University Medical Center , Stony Brook , NY , USA.
authors.forename: Nicos
authors.initials: N
authors.lastname: Labropoulos
authors.affiliation: a Department of Surgery-Vascular Surgery Unit, Medical School , University of Ioannina , Ioannina , Greece.
authors.forename: Miltiadis
authors.initials: M
authors.lastname: Matsagkas
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D001696:Biomechanical Phenomena; D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D003971:Diastole; D004548:Elasticity; D057510:Endovascular Procedures / Q000379:methods*; D064368:Healthy Volunteers; D006439:Hemodynamics; D006801:Humans; D057446:Hydrodynamics; D007083:Iliac Artery / Q000473:pathology; D007668:Kidney / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D011312:Pressure; D011474:Prosthesis Design; D018570:Risk Assessment; D033081:Shear Strength; D015607:Stents; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: Endovascular aneurysm repair; comparison; endograft; hemodynamics