title: The shear stess profile of the pivotal fenestrated endograft at the level of the renal branches: A computational study for complex aortic aneurysms.
abstract: OBJECTIVE
  This study investigated the impact of the variant angulations on the values and distribution of wall shear stress on the renal branches and the mating vessels of a pivotal fenestrated design.
  
  
  METHODS
  An idealized endograft model of two renal branches was computationally reconstructed with variable angulations of the left renal branch. These ranged from the 1:30' to 3:30' o'clock position, corresponding from 45° to 105° with increments of 15°. A fluid-structure-interaction analysis was performed to estimate the wall shear stress.
  
  
  RESULTS
  The proximal part of the renal branch preserved quite constant wall shear stress. The transition zone between its distal end and the renal artery showed the highest values compared to the proximal and middle segments, ranging from 8.9 to 12.4 Pa. The lowest stress values presented at 90° whereas the highest at 45°. The post-mating arterial segment showed constantly low stress values regardless of the pivotal branch angle (6.3 to 6.6 Pa). The 45° configuration showed a distribution of the highest stress posteriorly whereas the 105°-angulation anteriorly.
  
  
  CONCLUSIONS
  The variant horizontal branch orientation influences the wall shear stress distribution across its length and affects its values only at its transition with the mating vessel. These findings and their potential association with adverse effects deserve further clinical validation.
authors.affiliation: Department of Vascular Surgery, "Democritus" Medical School, University Hospital of Alexandroupolis, Greece efstratiosgeorg@gmail.com.
authors.forename: Efstratios
authors.initials: E
authors.lastname: Georgakarakos
authors.affiliation: Fluids Section, School of Mechanical Engineering, National Technical University of Athens, Athens, Greece.
authors.forename: Antonios
authors.initials: A
authors.lastname: Xenakis
authors.affiliation: Department of Vascular Surgery, St. Franziskus Hospital and University Clinic of Münster, Germany.
authors.forename: Theodosios
authors.initials: T
authors.lastname: Bisdas
authors.affiliation: Department of Vascular Surgery, "Democritus" Medical School, University Hospital of Alexandroupolis, Greece.
authors.forename: George S
authors.initials: GS
authors.lastname: Georgiadis
authors.affiliation: Department of Vascular Surgery, "Democritus" Medical School, University Hospital of Alexandroupolis, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Schoretsanitis
authors.affiliation: Liverpool Vascular and Endovascular Service, Royal Liverpool University Hospital, Liverpool, UK.
authors.forename: George A
authors.initials: GA
authors.lastname: Antoniou
authors.affiliation: Department of Vascular Surgery, "Democritus" Medical School, University Hospital of Alexandroupolis, Greece.
authors.forename: Miltos
authors.initials: M
authors.lastname: Lazarides
mesh_terms: D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001027:Aortography / Q000379:methods; D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D000072226:Computed Tomography Angiography; D003198:Computer Simulation; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation*; D006439:Hemodynamics; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D012039:Regional Blood Flow; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D013314:Stress, Mechanical; D016896:Treatment Outcome
keywords: Suprarenal aortic aneurysms; computational fluid dynamics; endograft; endovascular; fenestrated; hemodynamics; pivotal fenestrated endovascular; shear stress