title: Time-resolved 3-dimensional magnetic resonance phase contrast imaging (4D Flow MRI) analysis of hemodynamics in valve-sparing aortic root repair with an anatomically shaped sinus prosthesis.
abstract: The anatomically shaped sinus prosthesis (Uni-Graft W SINUS; Braun, Melsungen, Germany) used in valve-sparing aortic root replacement promises physiological hemodynamics believed to grant physiologic valve function. Using time-resolved 3-dimensional magnetic resonance phase contrast imaging (4D Flow MRI), we analyzed sinus vortex formation and transvalvular pressure gradients in patients with sinus prosthesis compared with age-matched and young healthy volunteers.
  
  
  
  Twelve patients with sinus prosthesis (55 ± 15 years), 12 age-matched and 6 young healthy volunteers (55 ± 6 years, 25 ± 3 years, respectively) were examined at 3T with a 4D flow magnetic resonance imaging sequence. Sinus vortices visualized by streamlines and time-resolved particle paths were graded on a 4-point Likert scale. Time resolved pressure differences of the left ventricular outflow tract and the ascending aorta to a reference point in the aortic bulb as well as the transvalvular pressure gradient were evaluated.
  
  
  
  4D flow visualizations revealed a propensity of the sinus prosthesis toward intermediate (50%) and large (28%) vortices compared with age-matched volunteers with small (61%) and intermediate (36%) vortices. Vortices in sinus prostheses had a similar configuration compared with those in volunteers. The peak transvalvular pressure gradient did not vary significantly between patients and age-matched volunteers (4.0 ± 0.9 mm Hg, 3.8 ± 0.7 mm Hg, P = .373), its temporal evolution resembled that of volunteers with a prolonged positive phase in patients.
  
  
  
  Hemodynamics closely relating to those of volunteers were confirmed in sinus prostheses, believed to grant physiological valve function. Minor differences are presumably attributed to graft compliance and temporal resolution of the acquisition. Nevertheless, long-term deterioration of valve function as it was described for straight grafts could potentially be decelerated using sinus prostheses.
authors.affiliation: Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Lübeck, Germany. Electronic address: Thekla.Oechtering@uksh.de.
authors.forename: Thekla H
authors.initials: TH
authors.lastname: Oechtering
authors.affiliation: Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Carl F
authors.initials: CF
authors.lastname: Hons
authors.affiliation: Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Sieren
authors.affiliation: Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Hunold
authors.affiliation: Fraunhofer MEVIS, Bremen, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Hennemuth
authors.affiliation: Fraunhofer MEVIS, Bremen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Huellebrand
authors.affiliation: Fraunhofer MEVIS, Bremen, Germany.
authors.forename: Johann
authors.initials: J
authors.lastname: Drexl
authors.affiliation: Department of Cardiac and Thoracic Vascular Surgery, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Scharfschwerdt
authors.affiliation: Department of Cardiac and Thoracic Vascular Surgery, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Doreen
authors.initials: D
authors.lastname: Richardt
authors.affiliation: Department of Cardiac and Thoracic Vascular Surgery, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Hans-Hinrich
authors.initials: HH
authors.lastname: Sievers
authors.affiliation: Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Barkhausen
authors.affiliation: Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Alex
authors.initials: A
authors.lastname: Frydrychowicz
mesh_terms: D000328:Adult; D000368:Aged; D001011:Aorta / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D016022:Case-Control Studies; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D066230:Patient-Specific Modeling; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D012039:Regional Blood Flow; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: 4D Flow MRI; 4D flow cardiovascular magnetic resonance; VSARR; sinus prosthesis; sinus vortices; sinuses of Valsalva; transvalvular pressure gradients; valve-sparing aortic root replacement