From the University Heart Center Hamburg, Hamburg, Germany.
Submitted for consideration July 2013; accepted for publication in revised form October 2013.
Disclosure: T.D. has received honoraria from HeartWare. The remaining authors have no conflicts of interest to report.
Reprint Requests: Tobias Deuse, MD, University Heart Center Hamburg, Martinistr. 52, 20246 Hamburg, Germany. Email: firstname.lastname@example.org.
Median sternotomy is associated with specific complications, and sternal wound infections carry a high risk for left ventricular assist device patients. Techniques using thoracotomy incisions and sparing the sternum are therefore being developed to reduce complications and increase patient safety. The HeartWare ventricular assist device (HVAD) continuous flow pump is a miniaturized full support device that lends itself especially well for lateral implantation. We here present our techniques for HVAD implantation with outflow to either the ascending or the descending aorta.
Although median sternotomy is the most widely used surgical incision for HeartWare ventricular assist device (HVAD) implantation, it is associated with a number of incision-associated complications, such as bleeding and postoperative mediastinitis.1 Furthermore, longitudinal opening of the pericardium has been speculated to provoke postoperative right ventricular (RV) failure, related to the discontinuation of pericardial RV support. Redo sternotomies, which are frequent in these patients for subsequent heart transplantation or device explant in the case of myocardial recovery, are technically demanding. We here describe our techniques for HVAD implantation through thoracotomy incisions, aiming at reducing operative invasiveness and reducing complications.
The patient is placed in supine position, prepared, and draped. Although off-pump HVAD implantation has been described, we prefer to use cardiopulmonary bypass (CPB), because we believe that inspection of the left ventricular (LV) apex and cavity is valuable to remove any thrombotic material and to remove adjacent trabeculae, which may interfere with blood inflow. Thus, a limited groin incision is performed and arteria and vena femoralis are cannulated for CPB.
A left-sided 8 cm anterior thoracotomy is performed in the fifth intercostal space (ICS) to access the LV apex (Figure 1A). A soft-tissue retractor and a minimally invasive intercostal retractor are placed. The pericardium is opened and restrained with stay sutures. Normothermic CPB is commenced to unload the LV. The HVAD sewing ring is attached to the LV apex in the usual position, which can easily be defined using the left anterior descending artery and posterior descending artery as guiding structures (Figure 1B). The tightening screw can be accessed best if pointing laterally. The apex is cored (Figure 1C), and the LV cavity is carefully inspected and all thrombotic material removed. The HVAD pump is inserted (Figure 1D), secured, and carefully de-aired. Next, the driveline is tunneled to exit in the left lower abdomen.
To attach the outflow graft to the ascending aorta, a 5 cm anterior parasternal skin incision is performed and the second ICS entered (Figure 1A). The ascending aorta can be reached through this incision as long as it is not entirely displaced to the left side of the sternum. The outflow graft is pulled through from the apical to the para-aortic thoracotomy (Figure 2A). In contrast to the technique earlier described,2 we advocate an intrapericardial course of the outflow graft, which permits safe subsequent sternotomy for heart transplantation. We do not detach the second rib as described by Popov et al.,2 because the ICS is large enough to place a side-biting clamp and perform the graft-to-aorta anastomosis (Figure 2B). After careful de-airing, the clamp is released, and the device started. At the end of the procedure, the minimally invasive incisions are closed (Figure 2C). A postoperative chest x-ray shows the device in place (Figure 2D).
In cases in which the ascending aorta is not suitable for LV assist device outflow because of calcifications, previous replacement, or patent venous grafts, the descending aorta can alternatively be used. In these cases, the left thoracotomy incision is extended to not only permit access to the LV apex but also the descending aorta. The pump is implanted in the same way as described above. The pulmonary ligament is divided to allow the outflow graft to course below the hilum to the proximal descending aorta. A side-biting clamp is placed, and the outflow graft anastomosis performed. Alternatively, the outflow graft can be attached first (Figure 3A), and the graft retrogradely de-aired as the pump is inserted. Care needs to be taken to properly adjust the length of the outflow graft to prevent kinking as the lung is inflated (Figure 3B). The pump speed is set under transesophageal echo control to allow intermittent aortic valve opening and to avoid stasis and thrombosis in the ascending aorta. The adequate pump speed was found to be similar to classic ascending outflow configuration.
Mitral valve surgery3 and tricuspid valve surgery are among the cardiac procedures, which are increasingly frequent being performed through minimally invasive thoracotomy incisions to avoid sternotomy. Novel, miniaturized partial support assist devices are specifically designed for implantation through a minithoracotomy. In line with this general trend, thoracotomy incisions are gaining popularity for full support assist devices as well. Gregoric et al.4 reported his technique of left subcostal and right thoracotomy incision for the implantation of the HeartMate II device or the Jarvik 2000, which was later adopted with minor modifications by Anyanwu.5 Minimal access implant techniques for the HVAD have also been described by Cheung et al.6 and Schmitto et al.,7 who use a hemisternotomy to connect the outflow graft and therefore do not avoid sternal division. Popov et al.2 reported a right thoracotomy to access the ascending aorta but used extra-pericardial outflow graft positioning, which we believe should be avoided.
Our technique combines several features from previous reports and is aiming at reducing surgical trauma, minimizing complications, and making repeat surgery as safe as possible.
1. Stulak JM, Romans T, Cowger J, et al. Delayed sternal closure does not increase late infection risk in patients undergoing left ventricular assist device implantation. J Heart Lung Transplant. 2012;31:1115–1119
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3. Seeburger J, Borger MA, Doll N, et al. Comparison of outcomes of minimally invasive mitral valve surgery for posterior, anterior and bileaflet prolapse. Eur J Cardiothorac Surg. 2009;36:532–538
4. Gregoric ID, La Francesca S, Myers T, et al. A less invasive approach to axial flow pump insertion. J Heart Lung Transplant. 2008;27:423–426
5. Anyanwu AC. Technique for less invasive implantation of Heartmate II left ventricular assist device without median sternotomy. Semin Thorac Cardiovasc Surg. 2011;23:241–244
6. Cheung A, Lamarche Y, Kaan A, et al. Off-pump implantation of the HeartWare HVAD left ventricular assist device through minimally invasive incisions. Ann Thorac Surg. 2011;91:1294–1296
7. Schmitto JD, Molitoris U, Haverich A, Strueber M. Implantation of a centrifugal pump as a left ventricular assist device through a novel, minimized approach: Upper hemisternotomy combined with anterolateral thoracotomy. J Thorac Cardiovasc Surg. 2012;143:511–513
HVAD implantation; thoracotomy