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Dr. Eric E. Roselli, Cleveland Clinic Heart and Vascular Institute, Thoracic and Cardiovascular Surgery, 9500 Euclid Avenue, Desk J4-1, Cleveland, Ohio 44195
MANY DIFFERENT APPROACHES ARE AVAILABLE FOR PERFORMING MINIMALLY INVASIVE AORTIC VALVE REPLACEMENT (AVR). The most commonly used incision is the upper hemi-sternotomy, which extends from the sternal notch to the right fourth intercostal space (ICS). Variations in the location of the valve within the thoracic cavity can increase the complexity of the procedure resulting in greater ischemic times or conversions to full sternotomy. Alternatives include extending the hemi-sternotomy into the right fifth ICS or the lower hemi-sternotomy extending from the xiphoid to the right third ICS. More recently, right second intercostal mini-thoracotomy incisions have been described. Potential advantages for a minimally invasive approach over conventional median sternotomy include decreased length of hospital stay, hospital costs and pain, as well as faster recovery and less red blood cell (RBC) use (1,2).
Four different cases are presented to illustrate the use of 3-dimensional (3D) reconstructed contrast-enhanced multidetector computed tomography (MDCT) images in preparation for a mini–aortic valve replacement. All cases employed MDCT technology (iCT256-slice scanner, Phillips, Andover, Massachusetts) to acquire prospectively triggered axial images following the administration of a low-osmolar iodinated contrast agent. For optimization of anatomic evaluation, multi-planar reconstruction, maximum intensity projections, volume rendered reconstructions and advanced 3D off-line post-processing were performed on a dedicated stand-alone workstation (AcquariusNET, TeraRecon, Inc., San Mateo, California).
Limiting the incision to something less than a full sternotomy offers the advantage of maintaining the integrity of the chest wall and the potential for improved respiratory mechanics. Yet mini-sternotomy incisions are not always feasible and there is a 2% to 4% conversion rate and longer ischemic times when compared with the standard median sternotomy (1,2). The operation is made much more challenging when the valve lies below the fourth ICS, which is more common with older patients and those with elongated aortas.
The current series describes 4 cases where the 3D computed tomography reconstructions were used to guide our surgical approach. The first case highlights the standard upper hemi-sternotomy through the fourth ICS. The computed tomography images in this case confirmed that the exposure would be adequate. The second through fourth cases illustrate the variability in location of the aortic valve within the thoracic cavity. Persisting with the standard upper hemi-sternotomy in these scenarios would have made the operations technically more demanding and potentially led to prolonged ischemic times and conversion to full sternotomy (Figs. 1–4).⇓⇓⇓
Minimally invasive valve surgery is a complex undertaking. Three-dimensional reconstructed MDCT images allow virtual planning of the exposure which may decrease ischemic times and conversion rates. In the current era of advanced imaging technology this valuable and practical tool should be utilized in all patients being considered for minimally invasive aortic valve surgery.
All authors have reported that they have no relationships relevant to the contents of this paper to disclose. Please see page 272 for the accompanying Editorial Comment by Stelzer.
- American College of Cardiology Foundation