- Email: [email protected]
Minimally Invasive Thoracic Left Ventricular Assist Device Implantation; Case Series Demonstrating an Integrated Multidisciplinary Strategy
Minimally Invasive Thoracic Left Ventricular Assist Device Implantation; Case Series Demonstrating an Integrated Multidisciplinary Strategy Chad E. Wagner, MD,* Julian S. Bick, MD,* Jason Kennedy, MD,* Nicholas Haglund, MD,† Matthew Danter, MD,‡ Mary E. Davis, MSc,†‡ Andrew Shaw, MBBS,* and Simon Maltais, MD, PhD‡ Objectives: The present report describes the authors’ initial experience with implantation of the Heartware left ventricular assist devices (HeartWare Inc., Framingham, MA). via a minimally invasive surgical approach without cardiopulmonary bypass. A detailed overview of the anesthesiologist’s role during the procedure, characteristics of the patient population, and short-term clinical outcomes are provided, and the clinical considerations that influence the decision to implant this device via an off-pump minimally invasive approach are outlined. Design: Retrospective medical record review. Setting: University hospital. Participants: Thirteen patients with advanced heart failure deemed candidates for off-pump minimally invasive left ventricular Heartware implantation as a bridge to heart transplantation. Interventions: The Heartware left ventricular assist device was implanted in all 13 patients via a minimally invasive approach. Measurements and Main Results: One patient required unplanned cardiopulmonary bypass to control bleeding
around the left ventricular outflow cannula. The average operating room time was 249.8 minutes ⫾ 46.2 minutes. Six of 13 patients required no intraoperative red blood cell transfusions. Seven patients were extubated within 12 hours after surgery. Two patients required reintubation within 48 hours. No patients required reoperation for bleeding. Average intensive care unit and hospital lengths of stay were 7.2 ⫾ 3.9 days and 13.4 ⫾ 3.6 days, respectively. There were no in-hospital deaths. Conclusions: Minimally invasive off-pump left ventricular Heartware implantation is an emerging alternative to placement by midline sternotomy. The authors speculate, based on their limited experience, that an off-pump thoracic strategy may be a desirable option for some patients and that clinical outcomes may be non-inferior to placement by midline sternotomy with cardiopulmonary bypass. & 2015 Elsevier Inc. All rights reserved.
T
After the decision to proceed with LV MIOP HVAD implantation has been made, the anesthesiologist uses a transthoracic ultrasound probe to identify and mark the left ventricular apex that is typically at the 5th or 6th intercostal space. Surgical exposure includes a j-shaped hemisternotomy at the 3rd intercostal space, an anterolateral thoracotomy at the ventricular apex, and exposure of the femoral vessels in the event that cardiopulmonary bypass is needed. The ascending aorta is inspected with an epiaortic ultrasound to definitively exclude pathology (calcification, aneurysms, plaques, dissections) that precludes placement of the HVAD inflow graft. Attention is turned to the left ventricular apex. The surgeon places a spinal needle in the left ventricular apex, and the anesthesiologist uses TEE to identify its location. This information is used by the surgeon to guide the optimal placement of the HVAD outflow cannula. Intravenous lidocaine and magnesium are administered routinely before left ventricular sewing ring placement to minimize arrhythmias that frequently are encountered. After the sewing ring is sutured to the left ventricular apex, the anesthesiologist and surgeon perform a carefully choreographed sequence of events. Heparin (300 units/kg) is administered to achieve a target activated coagulation time greater than 400 seconds. It is critical that the patient be heparinized adequately for cardiopulmonary bypass should it be needed emergently. The patient’s pacemaker, if present, is reprogrammed to a heart rate o50
he Heartware ventricular assist device (HVAD) is a centrifugal pump approved to bridge patients with advanced heart failure to heart transplantation.1–3 It is smaller than many other ventricular assist devices, allowing for pericardial implantation and exhibiting a lower profile in the mediastinum. Innovative minimally invasive surgical HVAD implantation techniques have been developed.4–7 In addition, the HVAD can be implanted in the left ventricle without cardiopulmonary bypass via a minimally invasive approach. Some patients who have had a previous midline sternotomy and deemed too high risk for standard left ventricular assist device implantation may benefit from left ventricular minimally invasive off-pump HVAD (LV MIOP HVAD) implantation. The authors’ initial experience with LV MIOP HVAD implantation, along with perioperative outcomes of interest, are reported.
METHODS The LV MIOP HVAD implantation procedure will be described. The patient is brought into the operating room. If present, the sensing function of the patient’s automated implanted cardioverter-defibrillator is suspended with a magnet. A device programmer is kept in the operating room, because reprogramming the pacemaker settings usually is required during the operation. An arterial pressure monitoring catheter is placed, and general anesthesia is induced. A single-lumen endotracheal tube, central venous introducer, pulmonary artery catheter, and transesophageal echocardiography (TEE) probe are placed in the patient. A TEE exam is performed. The surgeon and anesthesiologist review the TEE exam findings, as well as previously obtained computerized tomography and peripheral ultrasound studies, to determine if LV MIOP HVAD placement is appropriate. Table 1 lists the issues that influence the decision to proceed with LV MIOP HVAD implantation.
KEY WORDS: cardiac surgery, left ventricular assist device placement via thoracotomy, intensive care management, Heartware LVAD (HVAD)
From the Departments of *Cardiothoracic Anesthesiology and Critical Care, †Cardiology, and ‡Cardiac Surgery, Vanderbilt University Medical Center, Nashville, TN. Dr. Bick and Dr. Wagner contributed equally to this manuscript. Address reprint requests to Chad E Wagner, MD, Department of Cardiothoracic Anesthesiology and Critical Care, Vanderbilt University Medical Center, 1211 21st Avenue South, Suite 526 MAB, Nashville, TN 37212. E-mail: [email protected] © 2015 Elsevier Inc. All rights reserved. 1053-0770/2601-0001$36.00/0 http://dx.doi.org/10.1053/j.jvca.2014.11.007
Journal of Cardiothoracic and Vascular Anesthesia, Vol 29, No 2 (April), 2015: pp 271–274
271
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Table 1. Clinical Considerations That Influence the Decision to Implant a Left Ventricular HVAD Without Cardiopulmonary Bypass Comorbidity
Off-Pump HVAD Clinical Considerations
Aortic valve disease
Greater-than-moderate aortic regurgitation is an indication for midline sternotomy and on-pump HVAD placement Previous mechanical aortic Requires midline sternotomy and onvalve replacement pump HVAD placement Tricuspid valve disease Tricuspid valve disease requiring surgical intervention is an indication for midline sternotomy and on-pump HVAD placement Mitral valve stenosis Mitral valve stenosis requiring surgical intervention is an indication for midline sternotomy and on-pump HVAD placement Atrial shunting Small atrial shunts amenable to percutaneous occlusion devices may be observed following off-pump HVAD placement. Large shunts not amenable to percutaneous occlusion devices may require midline sternotomy and on-pump HVAD placement. Presence of left ventricular Requires on-pump HVAD placement to thrombus better visualize the left ventricular apex Aortic disease Severe ascending aorta calcification, aortic dissections, or aneurysms are contraindications to off-pump HVAD placement. Peripheral vascular disease The presence of femoral vessels that are inadequate for cardiopulmonary bypass cannulation is an indication for midline sternotomy and on-pump HVAD placement. Abbreviation: HVAD, Heartware ventricular assist device.
beats per minute. Adenosine is administered, creating brief periods of asystole. The brief period of cardiac immobility makes placement of the left ventricular outflow cannula less technically challenging. Further, the brief asystole reduces blood loss during left ventricular outflow cannula placement. The surgeon then allows a few blood ejections out of the outflow cannula, through the HVAD, and out the inflow graft to expel air from the left ventricle and HVAD. TEE is used to confirm adequate deairing of the left ventricle. The pacemaker rate is increased. Finally, the inflow graft is anastomosed to the ascending aorta, final deairing is performed, and the HVAD is turned on. TEE is used to assess cardiac response to the HVAD and flows are adjusted as the surgeon and anesthesiologist deem appropriate. Vigilant TEE cardiac surveillance is required to identify right ventricular failure and/or left ventricular “suck-down” events. Protamine is administered and the incisions are closed. All study data were extracted from the institutional review boardapproved ventricular assist device registry. Average and standard deviations of continuous variables were calculated with Microsoft Excel 2011. RESULTS
Over a 13-month period, 13 patients were deemed candidates to undergo LV MIOP HVAD implantation for bridge to heart transplantation. Preoperative patient characteristics and hemodynamic profiles are listed in Table 2 and Table 3, respectively. Three patients had a previous sternotomy. Twelve patients underwent successful LV MIOP HVAD implantation. One patient required unplanned cardiopulmonary bypass to control bleeding around the left ventricular outflow cannula. No patients required reoperation for bleeding. Seventy-one percent of patients were extubated within 12 hours of intensive care unit admission. One patient was extubated before leaving the operating room. Fourteen percent of patients required reintubation and bi-level positive airway pressure was required in 41% of patients. All patients recovered and were discharged from the hospital. One patient died of intractable and symptomatic ventricular fibrillation 31 days after surgery in an outside rehabilitation facility. Three patients underwent heart
Table 2. Preoperative Patient Characteristics Before Planned Off-Pump Minimally Invasive Left Ventricular HVAD Implantation
Patient
1 2 3 4 5 6 7 8 9 10 11 12 13 AVERAGE STD
Type of Heart Failure
Sex
Age
BMI
EF%
Kormos
Creatinine
Ischemic Ischemic Ischemic Non-Ischemic Non-Ischemic Ischemic Ischemic Ischemic Ischemic Non-Ischemic Non-Ischemic Non-Ischemic Non-Ischemic
male male male male female male male male male female male female male
62.2 61.8 57.9 63.6 64.8 66.6 67 63.6 45 38 30.4 40.7 65 55.8 12.6
24 30.8 30.8 34.7 30.4 31.6 21.59 29.3 30.8 26.3 37.9 22.9 26.3 29 4.7
17.5 20 22.5 25 15 12.5 17.5 25 12.5 22.5 12.5 7.5 22.5 17.8 5.6
0.27 0.58 0.48 0.72 0.428 0.59 0.58 0.6 0.71 0.384 0.9 0.421 NA 0.55 0.17
1.27 1.24 2.46 6.85 0.81 1.62 1.06 1.39 1.01 0.86 0.95 1.2 1.71 1.72 1.6
Abbreviations: BMI, body mass index; EF, ejection fraction; HVAD, Heartware ventricular assist device STD, standard deviation.
273
OFF PUMP LVAD IMPLANTATION
Table 3. Preoperative Hemodynamic Profiles Obtained During Evaluation for HVAD Implantation Arterial Blood Pressures Patient
1 2 3 4 5 6 7 8 9 10 11 12 13 AVG STD
Pulmonary Artery
CO Thermal
Systolic
Diastolic
Mean
SVR (Woods Units)
Systolic
Diastolic
Mean
PVR (Woods Units)
PA Wedge
3.38 5.88 3.32 5.57 2.5 3.16 2.3 5.17 2.83 4.2 4.61 2.64 5.42 4.14 1.26
107 101 107 80 112 91 94 100 109 94 106 105 113 101.05 9.11
74 61 78 47 71 55 54 66 77 51 73 76 76 66.07 11.1
84 77 88 55 85 67 67 79 89 65 85 86 88 78.07 11.03
19.2 10.41 19.42 6.1 37.06 17.4 16.9 14.02 22.08 13 14.32 24.93 16 17.75 7.58
49 32 52 75 66 65 50 43 48 45 75 34 37 51.61 14.52
24 18 28 33 32 28 7 19 25 17 44 15 18 23.69 9.54
31 22 38 46 45 40 28 23 33 31 57 24 27 34.23 10.47
2.22 0.93 4.63 3.05 5.08 3.5 1.73 2.51 5.58 1.76 6.51 1.56 0.8 3.06 1.86
22 16 23 29 35 29 24 10 14 22 27 19 23 22.54 6.75
Abbreviations: AVG, average; CO, cardiac output; HVAD, Heartware ventricular assist device ; PA, pulmonary artery; PVR, pulmonary vascular resistance; STD, standard deviation; SVR, systemic vascular resistence.
transplantation within 6 months of LV MIOP HVAD implantation. Table 4 lists other postoperative outcomes of interest. DISCUSSION
The minimally invasive approach may be desirable in the setting of previous heart surgery when sternal reentry can be avoided. Patients who are deemed too high risk for sternal reentry may be appropriate candidates for a minimally invasive HVAD with or without cardiopulmonary bypass. The successful conduct of LV MIOP HVAD implantation requires robust collaboration between the surgeon and the anesthesiologist. Proficiency in basic transthoracic echocardiography, basic
implanted pacemaker/defibrillator programming, advanced perioperative TEE, and familiarity with the procedure are critical. In the authors’ limited experience, postoperative pain is more difficult to control after the minimally invasive surgical approach than after sternotomy. The authors speculate that a multimodal pain control regimen may reduce pain with less respiratory depression than a purely opioid-based pain control strategy. Patients presenting for HVAD often have coexisting right ventricular dysfunction and may be vulnerable to increases in pulmonary artery pressures associated with pain and hypercarbia. Further clinical trials are required to examine the potential benefits of the LV MIOP HAVAD implantation.
Table 4. Perioperative and Postoperative Patient Outcomes for Patients Undergoing Planned Left Ventricular Minimally Invasive Off-Pump HVAD Implantation Patient
1 2 3 4 5 6 7 8 9 10 11 12 13 AVG STD
Minutes in Surgery
Intraoperative RBC Units
Hours to Extubation
ICU Days
Hospital Days
Creatinine at Discharge
258 235 332 221 265 242 255 209 155 235 235 283 322 249.8 46.2
2 2 0 0 0 0 1 2 0 1 0 1 2 0.85 0.9
14 6 9 0 13 5 12 6 7 28 9 9 64 14 16.4
7 7 17 5 5 4 7 4 10 11 2 5 9 7.2 3.9
20 13 17 10 12 17 11 11 15 17 8 10 13 13.4 3.6
0.97 2.06 1.56 8.46 0.55 2.08 0.93 1.27 0.89 0.97 1.47 0.96 1.2 1.8 2.05
NOTE. Patient 13 required emergent cardiopulmonary bypass to repair bleeding around the left ventricular outflow cannula. Abbreviations: AVG, average; HVAD, Heartware ventricular assist device; ICU, intensive care unit; RBC, red blood cell; STD, standard deviation.
274
WAGNER ET AL
REFERENCES 1. Tuzun E, Roberts K, Cohn WE, et al: In vivo evaluation of the HeartWare centrifugal ventricular assist device. Tex Heart Inst J 34: 406-411, 2007 2. Wieselthaler GM, O Driscoll G, Jansz P, et al: Initial clinical experience with a novel left ventricular assist device with a magnetically levitated rotor in a multi-institutional trial. J Heart Lung Transplant 29:1218-1225, 2010 3. Aaronson KD, Slaughter MS, Miller LW, et al: Use of an intrapericardial, continuous-flow, centrifugal pump in patients awaiting heart transplantation. Circulation 125:3191-3200, 2012 4. Bottio T, Bejko J, Gallo M, et al: Less invasive implantation of HeartWare left ventricular assist device. Multimed Man Cardiothorac Surg 2014 Jul 11 [Epub ahead of print].
5. 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 91:1294-1296, 2011 6. Garcia Sáez D, Mohite PN, Zych B, et al: Minimally invasive access for off-pump HeartWare left ventricular assist device explantation. Interact Cardiovasc Thorac Surg 17:581-582, 2013 7. Schmitto JD, Molitoris U, Haverich A, et al: 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 143:511-513, 2012
around the left ventricular outflow cannula. The average operating room time was 249.8 minutes ⫾ 46.2 minutes. Six of 13 patients required no intraoperative red blood cell transfusions. Seven patients were extubated within 12 hours after surgery. Two patients required reintubation within 48 hours. No patients required reoperation for bleeding. Average intensive care unit and hospital lengths of stay were 7.2 ⫾ 3.9 days and 13.4 ⫾ 3.6 days, respectively. There were no in-hospital deaths. Conclusions: Minimally invasive off-pump left ventricular Heartware implantation is an emerging alternative to placement by midline sternotomy. The authors speculate, based on their limited experience, that an off-pump thoracic strategy may be a desirable option for some patients and that clinical outcomes may be non-inferior to placement by midline sternotomy with cardiopulmonary bypass. & 2015 Elsevier Inc. All rights reserved.
T
After the decision to proceed with LV MIOP HVAD implantation has been made, the anesthesiologist uses a transthoracic ultrasound probe to identify and mark the left ventricular apex that is typically at the 5th or 6th intercostal space. Surgical exposure includes a j-shaped hemisternotomy at the 3rd intercostal space, an anterolateral thoracotomy at the ventricular apex, and exposure of the femoral vessels in the event that cardiopulmonary bypass is needed. The ascending aorta is inspected with an epiaortic ultrasound to definitively exclude pathology (calcification, aneurysms, plaques, dissections) that precludes placement of the HVAD inflow graft. Attention is turned to the left ventricular apex. The surgeon places a spinal needle in the left ventricular apex, and the anesthesiologist uses TEE to identify its location. This information is used by the surgeon to guide the optimal placement of the HVAD outflow cannula. Intravenous lidocaine and magnesium are administered routinely before left ventricular sewing ring placement to minimize arrhythmias that frequently are encountered. After the sewing ring is sutured to the left ventricular apex, the anesthesiologist and surgeon perform a carefully choreographed sequence of events. Heparin (300 units/kg) is administered to achieve a target activated coagulation time greater than 400 seconds. It is critical that the patient be heparinized adequately for cardiopulmonary bypass should it be needed emergently. The patient’s pacemaker, if present, is reprogrammed to a heart rate o50
he Heartware ventricular assist device (HVAD) is a centrifugal pump approved to bridge patients with advanced heart failure to heart transplantation.1–3 It is smaller than many other ventricular assist devices, allowing for pericardial implantation and exhibiting a lower profile in the mediastinum. Innovative minimally invasive surgical HVAD implantation techniques have been developed.4–7 In addition, the HVAD can be implanted in the left ventricle without cardiopulmonary bypass via a minimally invasive approach. Some patients who have had a previous midline sternotomy and deemed too high risk for standard left ventricular assist device implantation may benefit from left ventricular minimally invasive off-pump HVAD (LV MIOP HVAD) implantation. The authors’ initial experience with LV MIOP HVAD implantation, along with perioperative outcomes of interest, are reported.
METHODS The LV MIOP HVAD implantation procedure will be described. The patient is brought into the operating room. If present, the sensing function of the patient’s automated implanted cardioverter-defibrillator is suspended with a magnet. A device programmer is kept in the operating room, because reprogramming the pacemaker settings usually is required during the operation. An arterial pressure monitoring catheter is placed, and general anesthesia is induced. A single-lumen endotracheal tube, central venous introducer, pulmonary artery catheter, and transesophageal echocardiography (TEE) probe are placed in the patient. A TEE exam is performed. The surgeon and anesthesiologist review the TEE exam findings, as well as previously obtained computerized tomography and peripheral ultrasound studies, to determine if LV MIOP HVAD placement is appropriate. Table 1 lists the issues that influence the decision to proceed with LV MIOP HVAD implantation.
KEY WORDS: cardiac surgery, left ventricular assist device placement via thoracotomy, intensive care management, Heartware LVAD (HVAD)
From the Departments of *Cardiothoracic Anesthesiology and Critical Care, †Cardiology, and ‡Cardiac Surgery, Vanderbilt University Medical Center, Nashville, TN. Dr. Bick and Dr. Wagner contributed equally to this manuscript. Address reprint requests to Chad E Wagner, MD, Department of Cardiothoracic Anesthesiology and Critical Care, Vanderbilt University Medical Center, 1211 21st Avenue South, Suite 526 MAB, Nashville, TN 37212. E-mail: [email protected] © 2015 Elsevier Inc. All rights reserved. 1053-0770/2601-0001$36.00/0 http://dx.doi.org/10.1053/j.jvca.2014.11.007
Journal of Cardiothoracic and Vascular Anesthesia, Vol 29, No 2 (April), 2015: pp 271–274
271
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WAGNER ET AL
Table 1. Clinical Considerations That Influence the Decision to Implant a Left Ventricular HVAD Without Cardiopulmonary Bypass Comorbidity
Off-Pump HVAD Clinical Considerations
Aortic valve disease
Greater-than-moderate aortic regurgitation is an indication for midline sternotomy and on-pump HVAD placement Previous mechanical aortic Requires midline sternotomy and onvalve replacement pump HVAD placement Tricuspid valve disease Tricuspid valve disease requiring surgical intervention is an indication for midline sternotomy and on-pump HVAD placement Mitral valve stenosis Mitral valve stenosis requiring surgical intervention is an indication for midline sternotomy and on-pump HVAD placement Atrial shunting Small atrial shunts amenable to percutaneous occlusion devices may be observed following off-pump HVAD placement. Large shunts not amenable to percutaneous occlusion devices may require midline sternotomy and on-pump HVAD placement. Presence of left ventricular Requires on-pump HVAD placement to thrombus better visualize the left ventricular apex Aortic disease Severe ascending aorta calcification, aortic dissections, or aneurysms are contraindications to off-pump HVAD placement. Peripheral vascular disease The presence of femoral vessels that are inadequate for cardiopulmonary bypass cannulation is an indication for midline sternotomy and on-pump HVAD placement. Abbreviation: HVAD, Heartware ventricular assist device.
beats per minute. Adenosine is administered, creating brief periods of asystole. The brief period of cardiac immobility makes placement of the left ventricular outflow cannula less technically challenging. Further, the brief asystole reduces blood loss during left ventricular outflow cannula placement. The surgeon then allows a few blood ejections out of the outflow cannula, through the HVAD, and out the inflow graft to expel air from the left ventricle and HVAD. TEE is used to confirm adequate deairing of the left ventricle. The pacemaker rate is increased. Finally, the inflow graft is anastomosed to the ascending aorta, final deairing is performed, and the HVAD is turned on. TEE is used to assess cardiac response to the HVAD and flows are adjusted as the surgeon and anesthesiologist deem appropriate. Vigilant TEE cardiac surveillance is required to identify right ventricular failure and/or left ventricular “suck-down” events. Protamine is administered and the incisions are closed. All study data were extracted from the institutional review boardapproved ventricular assist device registry. Average and standard deviations of continuous variables were calculated with Microsoft Excel 2011. RESULTS
Over a 13-month period, 13 patients were deemed candidates to undergo LV MIOP HVAD implantation for bridge to heart transplantation. Preoperative patient characteristics and hemodynamic profiles are listed in Table 2 and Table 3, respectively. Three patients had a previous sternotomy. Twelve patients underwent successful LV MIOP HVAD implantation. One patient required unplanned cardiopulmonary bypass to control bleeding around the left ventricular outflow cannula. No patients required reoperation for bleeding. Seventy-one percent of patients were extubated within 12 hours of intensive care unit admission. One patient was extubated before leaving the operating room. Fourteen percent of patients required reintubation and bi-level positive airway pressure was required in 41% of patients. All patients recovered and were discharged from the hospital. One patient died of intractable and symptomatic ventricular fibrillation 31 days after surgery in an outside rehabilitation facility. Three patients underwent heart
Table 2. Preoperative Patient Characteristics Before Planned Off-Pump Minimally Invasive Left Ventricular HVAD Implantation
Patient
1 2 3 4 5 6 7 8 9 10 11 12 13 AVERAGE STD
Type of Heart Failure
Sex
Age
BMI
EF%
Kormos
Creatinine
Ischemic Ischemic Ischemic Non-Ischemic Non-Ischemic Ischemic Ischemic Ischemic Ischemic Non-Ischemic Non-Ischemic Non-Ischemic Non-Ischemic
male male male male female male male male male female male female male
62.2 61.8 57.9 63.6 64.8 66.6 67 63.6 45 38 30.4 40.7 65 55.8 12.6
24 30.8 30.8 34.7 30.4 31.6 21.59 29.3 30.8 26.3 37.9 22.9 26.3 29 4.7
17.5 20 22.5 25 15 12.5 17.5 25 12.5 22.5 12.5 7.5 22.5 17.8 5.6
0.27 0.58 0.48 0.72 0.428 0.59 0.58 0.6 0.71 0.384 0.9 0.421 NA 0.55 0.17
1.27 1.24 2.46 6.85 0.81 1.62 1.06 1.39 1.01 0.86 0.95 1.2 1.71 1.72 1.6
Abbreviations: BMI, body mass index; EF, ejection fraction; HVAD, Heartware ventricular assist device STD, standard deviation.
273
OFF PUMP LVAD IMPLANTATION
Table 3. Preoperative Hemodynamic Profiles Obtained During Evaluation for HVAD Implantation Arterial Blood Pressures Patient
1 2 3 4 5 6 7 8 9 10 11 12 13 AVG STD
Pulmonary Artery
CO Thermal
Systolic
Diastolic
Mean
SVR (Woods Units)
Systolic
Diastolic
Mean
PVR (Woods Units)
PA Wedge
3.38 5.88 3.32 5.57 2.5 3.16 2.3 5.17 2.83 4.2 4.61 2.64 5.42 4.14 1.26
107 101 107 80 112 91 94 100 109 94 106 105 113 101.05 9.11
74 61 78 47 71 55 54 66 77 51 73 76 76 66.07 11.1
84 77 88 55 85 67 67 79 89 65 85 86 88 78.07 11.03
19.2 10.41 19.42 6.1 37.06 17.4 16.9 14.02 22.08 13 14.32 24.93 16 17.75 7.58
49 32 52 75 66 65 50 43 48 45 75 34 37 51.61 14.52
24 18 28 33 32 28 7 19 25 17 44 15 18 23.69 9.54
31 22 38 46 45 40 28 23 33 31 57 24 27 34.23 10.47
2.22 0.93 4.63 3.05 5.08 3.5 1.73 2.51 5.58 1.76 6.51 1.56 0.8 3.06 1.86
22 16 23 29 35 29 24 10 14 22 27 19 23 22.54 6.75
Abbreviations: AVG, average; CO, cardiac output; HVAD, Heartware ventricular assist device ; PA, pulmonary artery; PVR, pulmonary vascular resistance; STD, standard deviation; SVR, systemic vascular resistence.
transplantation within 6 months of LV MIOP HVAD implantation. Table 4 lists other postoperative outcomes of interest. DISCUSSION
The minimally invasive approach may be desirable in the setting of previous heart surgery when sternal reentry can be avoided. Patients who are deemed too high risk for sternal reentry may be appropriate candidates for a minimally invasive HVAD with or without cardiopulmonary bypass. The successful conduct of LV MIOP HVAD implantation requires robust collaboration between the surgeon and the anesthesiologist. Proficiency in basic transthoracic echocardiography, basic
implanted pacemaker/defibrillator programming, advanced perioperative TEE, and familiarity with the procedure are critical. In the authors’ limited experience, postoperative pain is more difficult to control after the minimally invasive surgical approach than after sternotomy. The authors speculate that a multimodal pain control regimen may reduce pain with less respiratory depression than a purely opioid-based pain control strategy. Patients presenting for HVAD often have coexisting right ventricular dysfunction and may be vulnerable to increases in pulmonary artery pressures associated with pain and hypercarbia. Further clinical trials are required to examine the potential benefits of the LV MIOP HAVAD implantation.
Table 4. Perioperative and Postoperative Patient Outcomes for Patients Undergoing Planned Left Ventricular Minimally Invasive Off-Pump HVAD Implantation Patient
1 2 3 4 5 6 7 8 9 10 11 12 13 AVG STD
Minutes in Surgery
Intraoperative RBC Units
Hours to Extubation
ICU Days
Hospital Days
Creatinine at Discharge
258 235 332 221 265 242 255 209 155 235 235 283 322 249.8 46.2
2 2 0 0 0 0 1 2 0 1 0 1 2 0.85 0.9
14 6 9 0 13 5 12 6 7 28 9 9 64 14 16.4
7 7 17 5 5 4 7 4 10 11 2 5 9 7.2 3.9
20 13 17 10 12 17 11 11 15 17 8 10 13 13.4 3.6
0.97 2.06 1.56 8.46 0.55 2.08 0.93 1.27 0.89 0.97 1.47 0.96 1.2 1.8 2.05
NOTE. Patient 13 required emergent cardiopulmonary bypass to repair bleeding around the left ventricular outflow cannula. Abbreviations: AVG, average; HVAD, Heartware ventricular assist device; ICU, intensive care unit; RBC, red blood cell; STD, standard deviation.
274
WAGNER ET AL
REFERENCES 1. Tuzun E, Roberts K, Cohn WE, et al: In vivo evaluation of the HeartWare centrifugal ventricular assist device. Tex Heart Inst J 34: 406-411, 2007 2. Wieselthaler GM, O Driscoll G, Jansz P, et al: Initial clinical experience with a novel left ventricular assist device with a magnetically levitated rotor in a multi-institutional trial. J Heart Lung Transplant 29:1218-1225, 2010 3. Aaronson KD, Slaughter MS, Miller LW, et al: Use of an intrapericardial, continuous-flow, centrifugal pump in patients awaiting heart transplantation. Circulation 125:3191-3200, 2012 4. Bottio T, Bejko J, Gallo M, et al: Less invasive implantation of HeartWare left ventricular assist device. Multimed Man Cardiothorac Surg 2014 Jul 11 [Epub ahead of print].
5. 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 91:1294-1296, 2011 6. Garcia Sáez D, Mohite PN, Zych B, et al: Minimally invasive access for off-pump HeartWare left ventricular assist device explantation. Interact Cardiovasc Thorac Surg 17:581-582, 2013 7. Schmitto JD, Molitoris U, Haverich A, et al: 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 143:511-513, 2012