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Dyna-CT During Minimally Invasive Off-Pump Transapical Aortic Valve Implantation
Dyna-CT During Minimally Invasive Off-Pump Transapical Aortic Valve Implantation Jörg Kempfert, MD, Volkmar Falk, MD, PhD, Gerhard Schuler, MD, PhD, Axel Linke, MD, PhD, Denis Merk, MD, Friedrich W. Mohr, MD, PhD, and Thomas Walther, MD, PhD
Fig 1.
T
ransapical aortic valve implantation (AVI) has been successfully introduced into clinical practice in highrisk patients. Direct antegrade AVI is being performed under rapid ventricular pacing (RVP) using a minimally invasive off-pump technique. Optimal imaging of the aortic root is critical during transapical AVI to facilitate exact sizing of the aortic annulus and to avoid obstruction of the coronary arteries. Contemporary angiography systems allow intraoperative rotational angiography enabling three-dimensional reconstruction of the organs of interest: the DynaCT technique (Axiom Artis [Siemens Inc, Erlangen, Germany]). Unlike the use of preoperatively obtained computed tomographic (CT) data no registration process is necessary to overlay the resulting intraoperative three-dimensional reconstructions with the life image because the patient will not change position. To reduce the amount of contrast delivered during rotational angiography and to minimize motion artefacts, we established a new protocol using diluted contrast injection during RVP, which yields good image quality to determine special relations between the aortic annulus and the coronary arteries. Figure 1A shows the example of an
Address correspondence to Dr Walther, Universität Leipzig, Herzzentrum, Klinik für Herzchirurgie, Strümpellstr. 39, Leipzig, 04289, Germany; e-mail: [email protected].
© 2009 by The Society of Thoracic Surgeons Published by Elsevier Inc
intraoperative three-dimensional DynaCT image (Axiom Artis [Siemens Inc]) showing the relevant aortic root geometry (the right coronary artery is chronically occluded). This image was taken for a time span of 5 seconds simultaneously with the injection of diluted contrast (20 mL in 60 mL) at a rate of 20 mL/sec for 3 seconds. The RVP of 180/min was applied during image acquisition. The patient was in stable hemodynamic function throughout the procedure and returned to stable cardiac rhythm immediately after cessation of RVP. Dyna-CT imaging allowed for exact delineation of the distance of the left main coronary artery to the aortic annulus. Transapical AVI was then performed successfully in this patient (see Fig 1B showing valve prosthesis and pigtail catheter after implantation). Dyna-CT taken under RVP allows for three-dimensional imaging of the aortic root in the hybrid suite. This will allow for easy image integration of a three-dimensional model of the aortic root with life fluoroscopy during transcatheter AVI. We believe this technique will increase the overall accuracy of specialized imaging during transcatheter AVI. We acknowledge the technical support of Alois Nöttling from Siemens medical technologies who supported us during image registration.
Ann Thorac Surg 2009;88:2041 • 0003-4975/09/$36.00 doi:10.1016/j.athoracsur.2009.01.029
FEATURE ARTICLES
Departments of Cardiac Surgery and Cardiology, Heart Center, University of Leipzig, Leipzig, Germany
Fig 1.
T
ransapical aortic valve implantation (AVI) has been successfully introduced into clinical practice in highrisk patients. Direct antegrade AVI is being performed under rapid ventricular pacing (RVP) using a minimally invasive off-pump technique. Optimal imaging of the aortic root is critical during transapical AVI to facilitate exact sizing of the aortic annulus and to avoid obstruction of the coronary arteries. Contemporary angiography systems allow intraoperative rotational angiography enabling three-dimensional reconstruction of the organs of interest: the DynaCT technique (Axiom Artis [Siemens Inc, Erlangen, Germany]). Unlike the use of preoperatively obtained computed tomographic (CT) data no registration process is necessary to overlay the resulting intraoperative three-dimensional reconstructions with the life image because the patient will not change position. To reduce the amount of contrast delivered during rotational angiography and to minimize motion artefacts, we established a new protocol using diluted contrast injection during RVP, which yields good image quality to determine special relations between the aortic annulus and the coronary arteries. Figure 1A shows the example of an
Address correspondence to Dr Walther, Universität Leipzig, Herzzentrum, Klinik für Herzchirurgie, Strümpellstr. 39, Leipzig, 04289, Germany; e-mail: [email protected].
© 2009 by The Society of Thoracic Surgeons Published by Elsevier Inc
intraoperative three-dimensional DynaCT image (Axiom Artis [Siemens Inc]) showing the relevant aortic root geometry (the right coronary artery is chronically occluded). This image was taken for a time span of 5 seconds simultaneously with the injection of diluted contrast (20 mL in 60 mL) at a rate of 20 mL/sec for 3 seconds. The RVP of 180/min was applied during image acquisition. The patient was in stable hemodynamic function throughout the procedure and returned to stable cardiac rhythm immediately after cessation of RVP. Dyna-CT imaging allowed for exact delineation of the distance of the left main coronary artery to the aortic annulus. Transapical AVI was then performed successfully in this patient (see Fig 1B showing valve prosthesis and pigtail catheter after implantation). Dyna-CT taken under RVP allows for three-dimensional imaging of the aortic root in the hybrid suite. This will allow for easy image integration of a three-dimensional model of the aortic root with life fluoroscopy during transcatheter AVI. We believe this technique will increase the overall accuracy of specialized imaging during transcatheter AVI. We acknowledge the technical support of Alois Nöttling from Siemens medical technologies who supported us during image registration.
Ann Thorac Surg 2009;88:2041 • 0003-4975/09/$36.00 doi:10.1016/j.athoracsur.2009.01.029
FEATURE ARTICLES
Departments of Cardiac Surgery and Cardiology, Heart Center, University of Leipzig, Leipzig, Germany