title: Benchtop quantification of gutter formation and compression of chimney stent grafts in relation to renal flow in chimney endovascular aneurysm repair and endovascular aneurysm sealing configurations.
abstract: The chimney technique has been successfully used to treat juxtarenal aortic aneurysms. The two main issues with this technique are gutter formation and chimney graft (CG) compression, which induce a risk for type Ia endoleaks and stent thrombosis, respectively. In this benchtop study, the geometry and renal artery flow of chimney endovascular aneurysm repair configurations were compared with chimney configurations with endovascular aneurysm sealing (ch-EVAS).
  
  
  
  Seven flow phantoms were constructed, including one control and six chimney endovascular aneurysm repairs (Endurant [Medtronic Inc, Minneapolis, Minn] and AFX [Endologix Inc, Irvine, Calif]) or ch-EVAS (Nellix, Endologix) configurations, combined with either balloon-expandable or self-expanding CGs with an intended higher positioning of the right CG in comparison to the left CG. Geometric analysis was based on measurements at three-dimensional computed tomography angiography and included gutter volume and CG compression, quantified by the ratio between maximal and minimal diameter (D-ratio). In addition, renal artery flow was studied in a physiologic flow model and compared with the control.
  
  
  
  The average gutter volume was 343.5 ± 142.0 mm3, with the lowest gutter volume in the EVAS-Viabahn (W. L. Gore & Associates, Flagstaff, Ariz) combination (102.6 mm3) and the largest in the AFX-Advanta V12 (Atrium Medical Corporation, Hudson, NH) configuration (559.6 mm3). The maximum D-ratio was larger in self-expanding CGs than in balloon-expandable CGs in all configurations (2.02 ± 0.34 vs 1.39 ± 0.13). The CG compression had minimal influence on renal volumetric flow (right, 390.7 ± 29.4 mL/min vs 455.1 mL/min; left, 423.9 ± 28.3 mL/min vs 410.0 mL/min in the control).
  
  
  
  This study showed that gutter volume was lowest in ch-EVAS in combination with a Viabahn CG. CG compression was lower in configurations with the Advanta V12 than with Viabahn. Renal flow is unrestricted by CG compression.
authors.affiliation: Department of Surgery, Rijnstate Hospital, Arnhem, The Netherlands; Department of Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands; MIRA Research Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands. Electronic address: j.boersen@antoniusziekenhuis.nl.
authors.forename: Johannes T
authors.initials: JT
authors.lastname: Boersen
authors.affiliation: Department of Surgery, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Esme J
authors.initials: EJ
authors.lastname: Donselaar
authors.affiliation: Department of Surgery, Rijnstate Hospital, Arnhem, The Netherlands; MIRA Research Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Groot Jebbink
authors.affiliation: Department of Surgery, Rijnstate Hospital, Arnhem, The Netherlands; MIRA Research Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Roeliene
authors.initials: R
authors.lastname: Starreveld
authors.affiliation: Department of Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands; MIRA Research Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Overeem
authors.affiliation: MIRA Research Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Cornelis H
authors.initials: CH
authors.lastname: Slump
authors.affiliation: Department of Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: Jean-Paul P M
authors.initials: JPM
authors.lastname: de Vries
authors.affiliation: Department of Surgery, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Michel M P J
authors.initials: MMPJ
authors.lastname: Reijnen
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; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D000072226:Computed Tomography Angiography; D057867:Endoleak / Q000209:etiology / Q000503:physiopathology; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012079:Renal Circulation; D012307:Risk Factors; D015607:Stents; D013927:Thrombosis / Q000209:etiology / Q000503:physiopathology; D016896:Treatment Outcome; D014654:Vascular Patency