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Off-Pump HeartWare Ventricular Assist Device Implantation With Outflow Graft Anastomosis to the Left Subclavian Artery
Off-Pump HeartWare Ventricular Assist Device Implantation With Outflow Graft Anastomosis to the Left Subclavian Artery Julia Riebandt, MD, Thomas Haberl, MD, Stephane Mahr, MD, Angela Rajek, MD, Guenther Laufer, MD, Heinrich Schima, PhD, and Daniel Zimpfer, MD Departments of Cardiac Surgery and Anesthesia, General Intensive Care and Pain Management, and Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria
A novel, off-pump implantation technique for the HeartWare ventricular assist device with outflow graft anastomosis to the left subclavican artery is described. Cannulation of the left ventricular apex is performed through an incision in the left fourth or fifth intercostal space. The outflow graft is anastomosed to the left subclavian artery after tunneling through the left thoracic
cavity and the first intercostal space. This technique is especially appealing in redo cases as well as in patients with significant calcifications of the ascending aorta or in destination-therapy patients.
L
Technique
FEATURE ARTICLES
eft ventricular assist device (LVAD) implantation is an accepted treatment option for patients with end-stage heart failure [1]. Standard implantation technique includes median sternotomy with insertion of the LVAD inflow cannula to the left ventricular (LV) apex, anastomosis of the outflow graft to the ascending aorta, and cardiopulmonary bypass support. Alternatively, implantation can be performed through a full left lateral thoracotomy with placement of the LVAD inflow cannula to the LV apex and outflow graft to the descending aorta. Recently, an alternative approach for minimally invasive LVAD implantation through a minithoracotomy in the fourth or fifth intercostal space for placement of the inflow cannula to the LV apex and a right minithoracotomy for placement of the outflow graft to the ascending aorta has been described for selected patients and is now the standard approach for isolated LVAD implantation at our department [2]. We have refined this technique for redo cases and patients with significant calcification of the ascending aorta by anastomosing the outflow graft to the left subclavian artery after tunneling through the left thoracic cavity and the first intercostal space. A theoretical advantage of this approach lies within the fact that the first two aortic branches are bypassed and possible thrombus formations from the pump are less likely to ascend to cerebral arteries.
Accepted for publication Oct 11, 2013. Address correspondence to Dr Zimpfer, Department of Cardiac Surgery, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria; e-mail: [email protected].
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2014;97:2214–6) Ó 2014 by The Society of Thoracic Surgeons
Patient Preparation A preoperative computed tomography angiography is performed to rule out subclavian artery stenosis or subclavian vein thrombosis. The patient is placed in a supine position with the left arm out, standard endotracheal intubation is performed, and bilateral invasive blood pressure monitoring is established by means of arterial catheters in both radial arteries. External defibrillator pads are placed on the patient’s back to allow access to the left side of the thorax. Transesophageal echocardiography is performed in all patients to rule out relevant aortic or tricuspid regurgitation as well as persistent foramen ovale and apical thrombus formations. The patient is draped similarly to a standard procedure, leaving enough space for a left infraclavicular incision for access to the left subclavian artery and access to both groins for venous cannulation, in case circulatory support becomes necessary during the implantation.
Surgical Access to the Left Subclavian Artery A 6-cm incision 2 cm below and parallel to the left clavicle is performed for exposure of the left subclavian artery. The pectoralis major muscle is divided, the subclavian vein is retracted caudally, and the subclavian artery is dissected as long as possible for the later outflow graft anastomosis. Dissection is carried down to the thoracic wall, and the first intercostal space is identified. Depending on the diameter of the first intercostal space, the first rib is partially resected to suit a 16-mm Hegar dilator to prepare for tunneling of the LVAD outflow graft. At this time the incision in the fourth or fifth left intercostal space and opening of the pericardium are performed to avoid surgical dissection 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2013.10.054
under full anticoagulation with heparin. Thereafter, the patient is systemically anticoagulated with heparin.
Surgical Access to the Apex, Placement of Inflow Cannula, Tunneling of Outflow Graft, Anastomosis of the Outflow Graft to the Subclavian Artery, and Subclavian Artery Banding For exposure of the LV apex, an 8-cm incision in the fourth or fifth left intercostal space is performed, depending on the exact localization of the LV apex as assessed by transthoracic echocardiography. Thereafter, the HeartWare HVAD inflow cannula is inserted in a standard fashion as described previously [3]. The pump is connected, and air is removed. We then tunnel the outflow graft through the left-side thoracic cavity and first intercostal space. To avoid kinking and compression at the passage through the first intercostal space, the bend relief is shortened and the outflow graft is covered with a ring-reinforced Gore-Tex graft (16-mm diameter; W.L. Gore & Assoc, Flagstaff, AZ), which is then secured with nonadsorbable sutures. The operation is completed by anastomosing the outflow graft to the undersurface of the subclavian artery in an end-to-side technique. To avoid excessive blood flow to the left arm, we place a permanent banding (2 mm, polytetrafluoroethylene) band to the left subclavian artery distal to the outflow graft anastomosis, which is adjusted under invasive measurement of the right and left radial artery blood pressure targeting equal pressures to avoid hyperperfusioni or hypoperfusion. The operative result is depicted in Figure 1. Postoperative treatment including anticoagulation is performed with low-molecular weight heparin, followed by phenprocoumon and aspirin, and is identical to that for other HeartWare HVAD patients at our department.
Fig 1. Postoperative computed tomographic scan three-dimensional reconstruction.
HOW TO DO IT RIEBANDT ET AL OFF-PUMP HEARTWARE HVAD IMPLANTATION
2215
Comment We have established a novel, minimally invasive, and reproducible technique for HeartWare HVAD implantation that is especially appealing in redo cases, patients with significant atherosclerosis of the ascending aorta, and destination-therapy patients. The implantation can be performed off pump or with peripheral venoarterial extracorporeal membrane oxygenation as circulatory support in unstable patients instead of standard cardiopulmonary bypass to reduce the postoperative systemic inflammatory response and volume shifts. The left intercostal approach for placement of the inflow cannula is now routinely used in selected centers performing minimally invasive LVAD implantation. It has been proven to be not inferior to the standard approach through median sternotomy both in first operations as well as redo cases and will facilitate straightforward pump exchanges in the setting of pump thrombus formation or driveline fractures, rendering this approach especially attractive in destination patients. Still, it is technically more demanding as only the apex is exposed, requiring advanced experience in the selection of the proper site for apical coring. The anastomosis of the outflow graft to the subclavian artery has been performed at our center in 5 patients so far. Advantages are the relative ease of surgical exposure of the subclavian artery and the fact that it is usually free from artherosclerosis. Furthermore, this approach might reduce the overall ischemic cerebrovascular event rate, as the first two aortic branches are bypassed, which hinders the ascension of possible thrombus formations to cerebral vessels. However, there are concerns about this technique, including compression of the outflow graft, excessive blood flow to the arm, and flow disturbances on extensive elevation of the arm. Outflow graft compression can be avoided by using a ring-reinforced Gore-Tex graft at the site of passage through the first intercostal space. We have extensive experience with outflow graft anastomosis to the subclavian artery for extracorporeal membrane oxygenation and for LVAD. Sometimes massive differences in the arterial pressure can be observed intraoperatively; we believe that banding of the subclavian artery is mandatory if there is a mean pressure difference of more than 20 mm Hg to avoid excessive blood flow to the arm. In addition, it is important to educate the patient that blood pressure monitoring should not be obtained on the left arm. We have not observed any flow disturbances on elevation of the arm so far. Nevertheless, patients should be informed that such phenomena can potentially occur and extensive elevations of the arm, especially for longer times, should be avoided. To date, we have observed no complications such as arm swelling or dysfunction or change of pump variables with this technique. The described approach is a novel minimally invasive and reproducible technique for LVAD implantation in redo patients, destination patients, and patients with significant calcification of the ascending aorta, which at
FEATURE ARTICLES
Ann Thorac Surg 2014;97:2214–6
2216
HOW TO DO IT RIEBANDT ET AL OFF-PUMP HEARTWARE HVAD IMPLANTATION
the moment should be restricted to this selected high-risk population.
References 1. McMurray JJ, Adamopoulos S, Anker SD, et al, ESC Committee for Practice Guidelines. ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure 2012:
Ann Thorac Surg 2014;97:2214–6
the Task Force for the Diagnosis and Treatment of Acute and Chronic Heart Failure 2012 of the European Society of Cardiology. Developed in collaboration with the Heart Failure Association (HFA) of the ESC. Eur Heart J 2012;33:1787–847. 2. 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;91:1294–6. 3. Slaughter MS. Implantation of the HeartWare left ventricular assist device. Semin Thorac Cardiovasc Surg 2011;23:245–7.
FEATURE ARTICLES
A novel, off-pump implantation technique for the HeartWare ventricular assist device with outflow graft anastomosis to the left subclavican artery is described. Cannulation of the left ventricular apex is performed through an incision in the left fourth or fifth intercostal space. The outflow graft is anastomosed to the left subclavian artery after tunneling through the left thoracic
cavity and the first intercostal space. This technique is especially appealing in redo cases as well as in patients with significant calcifications of the ascending aorta or in destination-therapy patients.
L
Technique
FEATURE ARTICLES
eft ventricular assist device (LVAD) implantation is an accepted treatment option for patients with end-stage heart failure [1]. Standard implantation technique includes median sternotomy with insertion of the LVAD inflow cannula to the left ventricular (LV) apex, anastomosis of the outflow graft to the ascending aorta, and cardiopulmonary bypass support. Alternatively, implantation can be performed through a full left lateral thoracotomy with placement of the LVAD inflow cannula to the LV apex and outflow graft to the descending aorta. Recently, an alternative approach for minimally invasive LVAD implantation through a minithoracotomy in the fourth or fifth intercostal space for placement of the inflow cannula to the LV apex and a right minithoracotomy for placement of the outflow graft to the ascending aorta has been described for selected patients and is now the standard approach for isolated LVAD implantation at our department [2]. We have refined this technique for redo cases and patients with significant calcification of the ascending aorta by anastomosing the outflow graft to the left subclavian artery after tunneling through the left thoracic cavity and the first intercostal space. A theoretical advantage of this approach lies within the fact that the first two aortic branches are bypassed and possible thrombus formations from the pump are less likely to ascend to cerebral arteries.
Accepted for publication Oct 11, 2013. Address correspondence to Dr Zimpfer, Department of Cardiac Surgery, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria; e-mail: [email protected].
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2014;97:2214–6) Ó 2014 by The Society of Thoracic Surgeons
Patient Preparation A preoperative computed tomography angiography is performed to rule out subclavian artery stenosis or subclavian vein thrombosis. The patient is placed in a supine position with the left arm out, standard endotracheal intubation is performed, and bilateral invasive blood pressure monitoring is established by means of arterial catheters in both radial arteries. External defibrillator pads are placed on the patient’s back to allow access to the left side of the thorax. Transesophageal echocardiography is performed in all patients to rule out relevant aortic or tricuspid regurgitation as well as persistent foramen ovale and apical thrombus formations. The patient is draped similarly to a standard procedure, leaving enough space for a left infraclavicular incision for access to the left subclavian artery and access to both groins for venous cannulation, in case circulatory support becomes necessary during the implantation.
Surgical Access to the Left Subclavian Artery A 6-cm incision 2 cm below and parallel to the left clavicle is performed for exposure of the left subclavian artery. The pectoralis major muscle is divided, the subclavian vein is retracted caudally, and the subclavian artery is dissected as long as possible for the later outflow graft anastomosis. Dissection is carried down to the thoracic wall, and the first intercostal space is identified. Depending on the diameter of the first intercostal space, the first rib is partially resected to suit a 16-mm Hegar dilator to prepare for tunneling of the LVAD outflow graft. At this time the incision in the fourth or fifth left intercostal space and opening of the pericardium are performed to avoid surgical dissection 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2013.10.054
under full anticoagulation with heparin. Thereafter, the patient is systemically anticoagulated with heparin.
Surgical Access to the Apex, Placement of Inflow Cannula, Tunneling of Outflow Graft, Anastomosis of the Outflow Graft to the Subclavian Artery, and Subclavian Artery Banding For exposure of the LV apex, an 8-cm incision in the fourth or fifth left intercostal space is performed, depending on the exact localization of the LV apex as assessed by transthoracic echocardiography. Thereafter, the HeartWare HVAD inflow cannula is inserted in a standard fashion as described previously [3]. The pump is connected, and air is removed. We then tunnel the outflow graft through the left-side thoracic cavity and first intercostal space. To avoid kinking and compression at the passage through the first intercostal space, the bend relief is shortened and the outflow graft is covered with a ring-reinforced Gore-Tex graft (16-mm diameter; W.L. Gore & Assoc, Flagstaff, AZ), which is then secured with nonadsorbable sutures. The operation is completed by anastomosing the outflow graft to the undersurface of the subclavian artery in an end-to-side technique. To avoid excessive blood flow to the left arm, we place a permanent banding (2 mm, polytetrafluoroethylene) band to the left subclavian artery distal to the outflow graft anastomosis, which is adjusted under invasive measurement of the right and left radial artery blood pressure targeting equal pressures to avoid hyperperfusioni or hypoperfusion. The operative result is depicted in Figure 1. Postoperative treatment including anticoagulation is performed with low-molecular weight heparin, followed by phenprocoumon and aspirin, and is identical to that for other HeartWare HVAD patients at our department.
Fig 1. Postoperative computed tomographic scan three-dimensional reconstruction.
HOW TO DO IT RIEBANDT ET AL OFF-PUMP HEARTWARE HVAD IMPLANTATION
2215
Comment We have established a novel, minimally invasive, and reproducible technique for HeartWare HVAD implantation that is especially appealing in redo cases, patients with significant atherosclerosis of the ascending aorta, and destination-therapy patients. The implantation can be performed off pump or with peripheral venoarterial extracorporeal membrane oxygenation as circulatory support in unstable patients instead of standard cardiopulmonary bypass to reduce the postoperative systemic inflammatory response and volume shifts. The left intercostal approach for placement of the inflow cannula is now routinely used in selected centers performing minimally invasive LVAD implantation. It has been proven to be not inferior to the standard approach through median sternotomy both in first operations as well as redo cases and will facilitate straightforward pump exchanges in the setting of pump thrombus formation or driveline fractures, rendering this approach especially attractive in destination patients. Still, it is technically more demanding as only the apex is exposed, requiring advanced experience in the selection of the proper site for apical coring. The anastomosis of the outflow graft to the subclavian artery has been performed at our center in 5 patients so far. Advantages are the relative ease of surgical exposure of the subclavian artery and the fact that it is usually free from artherosclerosis. Furthermore, this approach might reduce the overall ischemic cerebrovascular event rate, as the first two aortic branches are bypassed, which hinders the ascension of possible thrombus formations to cerebral vessels. However, there are concerns about this technique, including compression of the outflow graft, excessive blood flow to the arm, and flow disturbances on extensive elevation of the arm. Outflow graft compression can be avoided by using a ring-reinforced Gore-Tex graft at the site of passage through the first intercostal space. We have extensive experience with outflow graft anastomosis to the subclavian artery for extracorporeal membrane oxygenation and for LVAD. Sometimes massive differences in the arterial pressure can be observed intraoperatively; we believe that banding of the subclavian artery is mandatory if there is a mean pressure difference of more than 20 mm Hg to avoid excessive blood flow to the arm. In addition, it is important to educate the patient that blood pressure monitoring should not be obtained on the left arm. We have not observed any flow disturbances on elevation of the arm so far. Nevertheless, patients should be informed that such phenomena can potentially occur and extensive elevations of the arm, especially for longer times, should be avoided. To date, we have observed no complications such as arm swelling or dysfunction or change of pump variables with this technique. The described approach is a novel minimally invasive and reproducible technique for LVAD implantation in redo patients, destination patients, and patients with significant calcification of the ascending aorta, which at
FEATURE ARTICLES
Ann Thorac Surg 2014;97:2214–6
2216
HOW TO DO IT RIEBANDT ET AL OFF-PUMP HEARTWARE HVAD IMPLANTATION
the moment should be restricted to this selected high-risk population.
References 1. McMurray JJ, Adamopoulos S, Anker SD, et al, ESC Committee for Practice Guidelines. ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure 2012:
Ann Thorac Surg 2014;97:2214–6
the Task Force for the Diagnosis and Treatment of Acute and Chronic Heart Failure 2012 of the European Society of Cardiology. Developed in collaboration with the Heart Failure Association (HFA) of the ESC. Eur Heart J 2012;33:1787–847. 2. 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;91:1294–6. 3. Slaughter MS. Implantation of the HeartWare left ventricular assist device. Semin Thorac Cardiovasc Surg 2011;23:245–7.
FEATURE ARTICLES