MULTIMEDIA MANUAL OF
doi:10.1093/mmcts/mmu008 published online 9 July 2014.
MMCTS
CARDIO-THORACIC SURGERY
Less invasive implantation of HeartWare left ventricular assist device† Tomaso Bottio*, Jonida Bejko, Michele Gallo, Giacomo Bortolussi and Gino Gerosa Department of Cardiology and Cardiovascular Surgery, University of Padova Medical School, Padova, Italy * Corresponding author. Via Giustiniani 2, 35100 Padova, Italy. Tel: +39-049-8212428; fax: +39-049-8212409; e-mail: [email protected] (T. Bottio). Received 18 December 2013; revised 24 March 2014; accepted 28 April 2014
Summary Mechanical support by means of ventricular assist devices is at present the most promising alternative of efforts aimed at increasing the supply of donor organs. The support of the left dysfunctional ventricle enables appropriate haemodynamic stabilization and recovery of secondary organ failure, often present in these severely ill patients. The current results of left ventricular assist device (LVAD) therapy for bridge to transplantation are excellent when compared with the outcome without the availability of this therapy. Additionally, a rapid extubation of these patients has demonstrated to be efficient in cardiac surgery for faster recovery and rehabilitation. Consequently, in recent years, surgical objectives have become much more clearly defined, and the concept of less invasive cardiac surgery can be applied to make this operation less complicated, anatomically focused with a greater clinical impact. We describe an LVAD implantation technique, applying the concept of less invasive cardiac surgery, consisting in the association of reduced surgical approaches, off-pump implantation and reduced administration of heparin dose, in order to achieve rapid extubation and rehabilitation of the patient, preserving low morbidity, and still meeting all the goals of the standard procedure. Keywords: HeartWare • Less invasive surgical technique
INTRODUCTION Implantation of a mechanical ventricular assist device in severe heart failure, opened to discussion decades ago, is now a wellestablished procedure for temporary support such as bridge to transplantation [1–4]. The haemodynamic fragility of these patients is well reported, and renal insufficiency, pulmonary hypertension as well as chronic obstructive pulmonary disease stand out as risk factors. Furthermore, when prolonged mechanical ventilation is required, the cerebral perfusion and peripheral oxygenation are compromised [5]. On the other hand, there is a growing trend towards the use of non-sternotomy incisions and/or minithoracotomy in all fields of cardiac surgery [6]. Although full-median sternotomy provides the best access to the heart and the adjacent structures, it could be replaced by smaller incisions in most of the cases. We describe the case of the implantation of the HeartWare left ventricular assist device (LVAD) in a young woman with a dilated cardiomyopathy, by using a ‘less invasive’ surgical technique, associating upper T-inverted ministernotomy with left anterior minithoracotomy. The choice of our approach association was directed by the possibility of a good exposure of the great vessels (upper ministernotomy), with facility on an eventual implantation of a right ventricular (RV) assistance in the case of right ventricle failure, and the heart no-touch technique for left ventricle apex exposure (minithoracotomy), with a decreased rate of arrhythmias and haemodynamic instability related to the heart manipulation, mandatory when in full sternotomy. The surgical risk at redo surgery is limited since the vascular
graft is protected by the pericardium. Additionally, less- extensive mediastinal dissection reduces the risk and the degree of postoperative bleeding, given the absolute indications of antithrombotic therapy after LVAD implantation. The issue is more important when these patients will be transplanted and therefore an eventual sensibilization due to excessive transfusions should be avoided. Finally, this approach allows preservation of the mechanics of the rib cage, with possible faster extubation after surgery.
The patient A 37-year-old woman who had experienced reduced exercise capacity for the last 6 months was admitted to our hospital because her clinical condition deteriorated rapidly into cardiogenic shock. Echocardiography revealed biventricular dilatation, reduced wall thickness, asynchronous left ventricular (LV) contraction and LV ejection fraction (LVEF) of 10%. ECG showed a left bundle branch block. Multiorgan failure developed including hepatic dysfunction (INR 7) and renal impairment. The same day, she was transferred to our institute and a left femoro- femoral extracorporeal membrane oxygenation (ECMO— oxygenator: Quadrox PLS, MAQUET Cardiovascular, Hirlingen, Germany and a centrifugal pump: Rotaflow, MAQUET Cardiovascular) was surgically implanted, in local anaesthesia. The day after, we performed the implantation of LVAD HeartWare by a left anterior small thoracotomy associated with mini-upper sternotomy, in ECMO support, and lower heparin dose administration.
© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
T. Bottio et al. / Multimedia Manual of Cardio-Thoracic Surgery
2
The system (kind permission of the Aptiva Medical, Official Distributor of HeartWare Ventricular Assist Device, Italy) The HeartWare Ventricular Assist Device (HVAD) system is an implantable ventricular assist device for the treatment of advanced heart failure. The system consists of a small pump with an integrated inflow cannula and outflow graft with strain relief, a driveline, an external controller and external power sources. The implant procedure makes use of a sewing ring and an apex coring tool, in addition to an equipment of surgical tools, which allows the pump to be attached to the apex of the left ventricle. The outflow graft is then attached to the ascending aorta (www. heartware.com). We report an alternative LVAD HeartWare implantation in a young patient as bridge to heart transplant (Video 1).
Video 1: HeartWare Ventricular Assist Device system (www.heartware.com) (reproduced with permission from HeartWare, Inc.).
Preparation of the system Once the strain relief was slided over the outflow graft, the outflow graft was stretched over the pump outflow conduit. Afterwards, the graft clamp screw was loosen and the graft clamp placed over the lip of the HVAD pump outflow conduit. Next, the clamp screw was tightened slightly with the hex driver, and the strain relief rotated so that clamp screw was located on the inner side of the outflow conduit. The clamp screw was tightened until resistance was met. We attached the sterile driveline extension cable to the HVAD pump, then passed the distal portion of the cable to the non-sterile assistant. The pump was submerged completely in a basin with 2 l of 5% dextrose solution, filled with dextrose and rotated with the inflow cannula facing up in the dextrose to allow any trapped air to escape. Once de-aired, the pump was run for 30–60 s. After the test was completed, and the pump stopped, the driveline extension cable was disconnected from the controller and the inflow cannula of the pump was covered with the yellow inflow cap (Video 2).
Video 2: Preparation of the HeartWare system.
SURGICAL TECHNIQUE Anterior left minithoracotomy We started by making a small anterior thoracotomy, opened the pericardium and exposed the LV apex. We selected the insertion site for the HeartWare pump inflow cannula, by using transoesophageal echocardiography. The site was selected anterior to the LV apex with the inflow cannula pointing to the mitral valve and parallel to the interventricular septum. We then attached the sewing ring to the myocardium using 12 pledgeted, doublearmed polypropylene sutures, and reinforced the sutures with bioglue surgical adhesive (Video 3).
Pump implantation We performed a full-thickness cruciate incision inside the sewing ring with an 11-blade scalpel, and by using the customized apical coring tool, we removed the apical core. Meanwhile, a clamp remained placed on the pump outflow graft. After removing the inflow cap from the HVAD pump inflow cannula, we
Video 3: Left ventricle apex exposure.
inserted the inflow cannula into the ventricle, ensuring the pump was in the right position and tightened the sewing ring’s screw around the HeartWare pump inflow conduit until an audible ‘click’ was heard (Video 4).
T-upper reversed ministernotomy Next, we made a median high ministernotomy incision, opened the pericardium to expose aorta and pulmonary artery. The choice
3
T. Bottio et al. / Multimedia Manual of Cardio-Thoracic Surgery
Video 4: Apical coring procedure and pump insertion.
Video 5: Upper ministernotomy for ascending aorta exposure.
of this approach association was directed by the possibility of a good exposure of the great vessels, with facility on an eventual implantation of an RV assistance in case of RV failure. The outflow vascular tract was tunnelled underneath the left minithoracotomy to the high ministernotomy, in the intra-pericardial position, by using a curved Kelly as a guide and following the inner surface of the pericardium with the instrument. Then, the graft is stretched in order to measure and cut the right length without kinking or overstretching it (Video 5).
Driveline placement Once submerged the external surface of the driveline’s woven polyester velour into antibiotic solution we selected the location where the driveline would exit the skin. A subcutaneous path was created by using the tunneller tool pulling it to the preselected exit point. The LVAD driveline was then connected to the instrument and tunnelled into the path. Next dried and the driveline passed to the assistant who connected it to the controller. Retaining sutures were used for immobilization at the skin. (Video 6).
Video 6: Driveline tunnelization.
Outflow-graft implantation We placed a side clamp on the ascending aorta where the outflow graft would be placed. Once made a longitudinal arteriotomy, we sew the outflow graft to the aorta with a 4-0 polypropylene suture, reinforcing the sutures with bioglue surgical adhesive. We placed a sterile 18-gauge needle into the outflow graft between the pump and the outflow graft clamp. After all air bubbles were removed, the 18-gauge needle was removed, and the needle hole was oversewed. Finally, the outflow graft clamp and the aorta side clamp were released, and HeartWare pump speed gradually increased to achieve the desired flow. Under transoesophageal echocardiographic control, after complete resumption of mechanical ventilation, the ECMO support was gradually reduced (Video 7). Before the mini-sternal wound and the thoracotomy were closed according to the standard protocol, the pump was isolated from the pulmonary pleura by wrapping it in a sheet of Teflon. The patient was discharged from the hospital after almost one month. Now she is eligible for the transplant programme and is included in the waiting list for a donor heart (Video 8).
Video 7: Outflow-graft anastomosis and pump starting.
RESULTS Twenty-one patients were supported with the HeartWare® LVAD at our centre from January 2012 to December 2013. The same surgical technique (off-pump implantation, minimally invasive surgical
4
T. Bottio et al. / Multimedia Manual of Cardio-Thoracic Surgery
Table 1: Baseline characteristics of 21 patients implanted with the HeartWare LVAD in minimally invasive fashion (n = 21)
Video 8: Patient outcome.
approach) was applied. Twelve patients received the VAD with the aid of regional paravertebral block analgesia associated with mild general anaesthesia (low doses of short-half time anaesthetic drugs), while the remaining 9 patients were routinely anaesthetized (complete general anaesthesia). Thoracic paravertebral block analgesia allowed a faster postoperative weaning from the mild general anaesthesia associated, by providing adequate postoperative pain support without haemodynamic impairment and consequently fast weaning from the mechanical ventilation, making possible the extubation in the operating room (OR) in 9 of 12 patients (75%). The remaining patients were extubated in the intensive care unit 2–48 h later. Three patients required temporary right paracorporeal VAD support, with possible later on weaning and decannulation at almost 48-72 h after the LVAD implant (Table 1).
DISCUSSION LVADs have become an important option for the treatment of patients with advanced heart failure [7, 8]. Unfortunately, patients undergoing LVAD implantation still experience considerable perioperative and postoperative morbidity and mortality. Major non-device-associated complications are represented by RV failure, bleeding and prolonged ventilationrelated morbidity [9].
Right ventricular failure Early postoperative RV failure is associated with increased rates of short-term morbidity and mortality and still remains difficult to predict [10]. According to our experience, the following are the reasons that make this less invasive approach effective in the management of a possible RV failure. In case of unpredicted rapid evolution of RV failure after LVAD implantation in the OR, a good exposure of the pulmonary artery is available in the upper high ministernotomy, with possibility of rapid setting of temporary RV support without additional surgical difficulty or increased operative risk for the patient. The association of the minithoracotomy with the mini-high sternotomy allows preservation of mechanical respiratory physiology, with possible early extubation. This enables a rapid transit
Median age (mean years ± SD) Gender male (%) BSA (m2, mean ± SD) Diagnosis (%) Dilated cardiomyopathy Ischaemic cardiomyopathy Indications (%) Bridge to transplantation Bridge to candidacy Destination therapy Diabetes (%) Preop creatinine clearance (ml/min, mean ± SD) Preop chronic renal failure (%) COPD (%) PAP mean (mean mmHg ± SD) EF (%) TAPSE (%) INTERMACS (%) I II EUROSCORE II (mean ± SD) Preoperative ‘fast-ECMO’ support (%) ASA Class I/II/III/IV Perioperative ECMO support (%) Other procedures associated (%) Extubated in OR (%) Mechanical ventilation (h, mean ± SD) Length of stay (mean ± SD) ICU Ward Duration of inotropic support (h, mean ± SD) Postoperative RVAD support (%) Discharged home (%) ARF supported by CVVH (%) Stroke (%) Transplantation (%) Days of device (days, mean ± SD) Death (%)
49.25 ± 7.11 19/21 1.84 ± 0.11 16/21 5/21 21/21 0 0 6/21 67 ± 19 18/21 4/21 28 ± 11 18 ± 5 16 ± 4 8/21 13/21 23 ± 16 6/21 0/0/5/16 0 0 9/21 17.08 ± 11.79 7.3 ± 10.2 29.3 ± 40.0 143.2 ± 62.1 3/21 20/21 4/21 2/21 7/21 192 ± 115 1/21
BSA: body mass index; COPD: chronic obstructive pulmonary disease; Pulmonary arterial pressure; ECMO: extracorporeal membrane oxygenation; EF: ejection fraction; RVAD: right ventricular mechanical support; ARF: acute renal failure; ICU: intensive care unit.
from a pressure-positive mechanical ventilation towards a physiological pressure-negative spontaneous breathing, favouring downloading of the right ventricle frequently compromised in these patients. Additionally, the heart no-touch technique for left ventricle apex exposure (minithoracotomy) presents a decreased rate of arrhythmias and haemodynamic instability related to the heart manipulation, mandatory when in full sternotomy.
Bleeding Our policy is to establish ECMO support in the OR if cardiac manipulation is not tolerated. A single bolus of 5000 IU of intravenous heparin is used either for the ECMO and the pump implantation, in order to limit surgical bleeding and thus lower number of blood unit transfusion. The association of low doses of operative intravenous heparin to less-extensive mediastinal dissection reduces the risk and the degree of postoperative haemorrhage.
5
T. Bottio et al. / Multimedia Manual of Cardio-Thoracic Surgery
Furthermore, the surgical risk of a redo surgery for the patient treated with the LVAD as bridge to transplantation is limited since the vascular graft at reintervention is protected by the pericardium.
Prolonged ventilation-related morbidity Postoperative prolonged ventilation is one of the factors with the strongest mortality association risk in cardiac surgery [11]. Additionally, ventilator-associated pneumonia is the second most common hospital-acquired infection after blood stream infections, with a significant impact on patient morbidity and mortality [12]. Furthermore, mini-invasive cardiac surgery, compared with conventional full sternotomy cardiac surgery, is associated with decreased bleeding, blood product transfusion, sternal wound infection, scar dissatisfaction, ventilation time, intensive care unit stay, hospital length of stay and reduced time to return to normal activity, thereby resulting in better outcomes [13]. Conflict of interest: none declared.
REFERENCES [1] McLoughlin MP, Chapman JR, Gordon SV, Ledwich M, Macdonald G, Mohacsi P. ‘Go on—say yes’: a publicity campaign to increase commitment to organ donation on the driver’s license in New South Wales. Transplant Proc 1991;23:2693. [2] Daniel J. Goldstein, Mehmet C. Oz, Eric A. Rose. Implantable left ventricular assist devices. N Engl J Med 1998;339:1522–33. [3] Worku B, Naka Y, Pak SW, Cheema FH, Siddiqui OT, Jain J et al. Predictors of mortality after short-term ventricular assist device placement. Ann Thorac Surg 2011;92:1608–12.
[4] Casarotto D, Bottio T, Gambino A, Testolin L, Gerosa G. The last to die is hope: prolonged mechanical circulatory support with a Novacor left ventricular assist device as a bridge to transplantation. J Thorac Cardiovasc Surg 2003;125:417–8. [5] Davies RG, Myles PS, Graham JM. A comparison of the analgesic efficacy and side-effects of paravertebral vs epidural blockade for thoracotomy. A systematic review and meta-analysis of randomized trials. Br J Anaesth 2006;96:418–26. [6] Bottio T, Bisleri G, Piccoli P, Negri A, Manzato A, Muneretto C. Heart valve surgery in a very high-risk population: a preliminary experience in awake patients. J Heart Valve Dis 2007;16:187–94. [7] Wever-Pinzon O, Drakos SG, Kfoury AG, Nativi JN, Gilbert EM, Everitt M et al. Morbidity and mortality in heart transplant candidates supported with mechanical circulatory support: is reappraisal of the current united network for organ sharing thoracic organ allocation policy justified? Circulation 2013;127:452–62. [8] Kirklin JK, Naftel DC, Kormos RL, Stevenson LW, Pagani FD, Miller MA et al. Second INTERMACS annual report: more than 1,000 primary left ventricular assist device implants. J Heart Lung Transplant 2010;29:1–10. [9] Deng MC, Loebe M, El-Banayosy A, Gronda E, Jansen PG, Vigano M et al. Mechanical circulatory support for advanced heart failure: effect of patient selection on outcome. Circulation 2001;103:231–7. [10] Gerosa G, Gallo M, Tarzia V, Di Gregorio G, Zanella F, Bottio T. Less invasive surgical and perfusion technique for implantation of the Jarvik 2000 left ventricular assist device. Ann Thorac Surg 2013;96:712–4. [11] La Par DJ, Gillen JR, Crosby IK, Sawyer RG, Lau CL, Kron IL et al. Predictors of operative mortality in cardiac surgical patients with prolonged intensive care unit duration. J Am Coll Surg 2013;216:1116–23. [12] Tablan OC, Anderson LJ, Besser R, Bridges C, Hajjeh R, CDC; Healthcare Infection Control Practices Advisory Committee. Guidelines for preventing health-care—associated pneumonia, 2003: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee. MMWR Recomm Rep 2004;53:1–36. [13] Cheng DC, Martin J, Lal A, Diegeler A, Folliguet TA, Nifong LW et al. Minimally invasive versus conventional open mitral valve surgery: a metaanalysis and systematic review. Innovations (Phila) 2011;6:84–103.
doi:10.1093/mmcts/mmu008 published online 9 July 2014.
MMCTS
CARDIO-THORACIC SURGERY
Less invasive implantation of HeartWare left ventricular assist device† Tomaso Bottio*, Jonida Bejko, Michele Gallo, Giacomo Bortolussi and Gino Gerosa Department of Cardiology and Cardiovascular Surgery, University of Padova Medical School, Padova, Italy * Corresponding author. Via Giustiniani 2, 35100 Padova, Italy. Tel: +39-049-8212428; fax: +39-049-8212409; e-mail: [email protected] (T. Bottio). Received 18 December 2013; revised 24 March 2014; accepted 28 April 2014
Summary Mechanical support by means of ventricular assist devices is at present the most promising alternative of efforts aimed at increasing the supply of donor organs. The support of the left dysfunctional ventricle enables appropriate haemodynamic stabilization and recovery of secondary organ failure, often present in these severely ill patients. The current results of left ventricular assist device (LVAD) therapy for bridge to transplantation are excellent when compared with the outcome without the availability of this therapy. Additionally, a rapid extubation of these patients has demonstrated to be efficient in cardiac surgery for faster recovery and rehabilitation. Consequently, in recent years, surgical objectives have become much more clearly defined, and the concept of less invasive cardiac surgery can be applied to make this operation less complicated, anatomically focused with a greater clinical impact. We describe an LVAD implantation technique, applying the concept of less invasive cardiac surgery, consisting in the association of reduced surgical approaches, off-pump implantation and reduced administration of heparin dose, in order to achieve rapid extubation and rehabilitation of the patient, preserving low morbidity, and still meeting all the goals of the standard procedure. Keywords: HeartWare • Less invasive surgical technique
INTRODUCTION Implantation of a mechanical ventricular assist device in severe heart failure, opened to discussion decades ago, is now a wellestablished procedure for temporary support such as bridge to transplantation [1–4]. The haemodynamic fragility of these patients is well reported, and renal insufficiency, pulmonary hypertension as well as chronic obstructive pulmonary disease stand out as risk factors. Furthermore, when prolonged mechanical ventilation is required, the cerebral perfusion and peripheral oxygenation are compromised [5]. On the other hand, there is a growing trend towards the use of non-sternotomy incisions and/or minithoracotomy in all fields of cardiac surgery [6]. Although full-median sternotomy provides the best access to the heart and the adjacent structures, it could be replaced by smaller incisions in most of the cases. We describe the case of the implantation of the HeartWare left ventricular assist device (LVAD) in a young woman with a dilated cardiomyopathy, by using a ‘less invasive’ surgical technique, associating upper T-inverted ministernotomy with left anterior minithoracotomy. The choice of our approach association was directed by the possibility of a good exposure of the great vessels (upper ministernotomy), with facility on an eventual implantation of a right ventricular (RV) assistance in the case of right ventricle failure, and the heart no-touch technique for left ventricle apex exposure (minithoracotomy), with a decreased rate of arrhythmias and haemodynamic instability related to the heart manipulation, mandatory when in full sternotomy. The surgical risk at redo surgery is limited since the vascular
graft is protected by the pericardium. Additionally, less- extensive mediastinal dissection reduces the risk and the degree of postoperative bleeding, given the absolute indications of antithrombotic therapy after LVAD implantation. The issue is more important when these patients will be transplanted and therefore an eventual sensibilization due to excessive transfusions should be avoided. Finally, this approach allows preservation of the mechanics of the rib cage, with possible faster extubation after surgery.
The patient A 37-year-old woman who had experienced reduced exercise capacity for the last 6 months was admitted to our hospital because her clinical condition deteriorated rapidly into cardiogenic shock. Echocardiography revealed biventricular dilatation, reduced wall thickness, asynchronous left ventricular (LV) contraction and LV ejection fraction (LVEF) of 10%. ECG showed a left bundle branch block. Multiorgan failure developed including hepatic dysfunction (INR 7) and renal impairment. The same day, she was transferred to our institute and a left femoro- femoral extracorporeal membrane oxygenation (ECMO— oxygenator: Quadrox PLS, MAQUET Cardiovascular, Hirlingen, Germany and a centrifugal pump: Rotaflow, MAQUET Cardiovascular) was surgically implanted, in local anaesthesia. The day after, we performed the implantation of LVAD HeartWare by a left anterior small thoracotomy associated with mini-upper sternotomy, in ECMO support, and lower heparin dose administration.
© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
T. Bottio et al. / Multimedia Manual of Cardio-Thoracic Surgery
2
The system (kind permission of the Aptiva Medical, Official Distributor of HeartWare Ventricular Assist Device, Italy) The HeartWare Ventricular Assist Device (HVAD) system is an implantable ventricular assist device for the treatment of advanced heart failure. The system consists of a small pump with an integrated inflow cannula and outflow graft with strain relief, a driveline, an external controller and external power sources. The implant procedure makes use of a sewing ring and an apex coring tool, in addition to an equipment of surgical tools, which allows the pump to be attached to the apex of the left ventricle. The outflow graft is then attached to the ascending aorta (www. heartware.com). We report an alternative LVAD HeartWare implantation in a young patient as bridge to heart transplant (Video 1).
Video 1: HeartWare Ventricular Assist Device system (www.heartware.com) (reproduced with permission from HeartWare, Inc.).
Preparation of the system Once the strain relief was slided over the outflow graft, the outflow graft was stretched over the pump outflow conduit. Afterwards, the graft clamp screw was loosen and the graft clamp placed over the lip of the HVAD pump outflow conduit. Next, the clamp screw was tightened slightly with the hex driver, and the strain relief rotated so that clamp screw was located on the inner side of the outflow conduit. The clamp screw was tightened until resistance was met. We attached the sterile driveline extension cable to the HVAD pump, then passed the distal portion of the cable to the non-sterile assistant. The pump was submerged completely in a basin with 2 l of 5% dextrose solution, filled with dextrose and rotated with the inflow cannula facing up in the dextrose to allow any trapped air to escape. Once de-aired, the pump was run for 30–60 s. After the test was completed, and the pump stopped, the driveline extension cable was disconnected from the controller and the inflow cannula of the pump was covered with the yellow inflow cap (Video 2).
Video 2: Preparation of the HeartWare system.
SURGICAL TECHNIQUE Anterior left minithoracotomy We started by making a small anterior thoracotomy, opened the pericardium and exposed the LV apex. We selected the insertion site for the HeartWare pump inflow cannula, by using transoesophageal echocardiography. The site was selected anterior to the LV apex with the inflow cannula pointing to the mitral valve and parallel to the interventricular septum. We then attached the sewing ring to the myocardium using 12 pledgeted, doublearmed polypropylene sutures, and reinforced the sutures with bioglue surgical adhesive (Video 3).
Pump implantation We performed a full-thickness cruciate incision inside the sewing ring with an 11-blade scalpel, and by using the customized apical coring tool, we removed the apical core. Meanwhile, a clamp remained placed on the pump outflow graft. After removing the inflow cap from the HVAD pump inflow cannula, we
Video 3: Left ventricle apex exposure.
inserted the inflow cannula into the ventricle, ensuring the pump was in the right position and tightened the sewing ring’s screw around the HeartWare pump inflow conduit until an audible ‘click’ was heard (Video 4).
T-upper reversed ministernotomy Next, we made a median high ministernotomy incision, opened the pericardium to expose aorta and pulmonary artery. The choice
3
T. Bottio et al. / Multimedia Manual of Cardio-Thoracic Surgery
Video 4: Apical coring procedure and pump insertion.
Video 5: Upper ministernotomy for ascending aorta exposure.
of this approach association was directed by the possibility of a good exposure of the great vessels, with facility on an eventual implantation of an RV assistance in case of RV failure. The outflow vascular tract was tunnelled underneath the left minithoracotomy to the high ministernotomy, in the intra-pericardial position, by using a curved Kelly as a guide and following the inner surface of the pericardium with the instrument. Then, the graft is stretched in order to measure and cut the right length without kinking or overstretching it (Video 5).
Driveline placement Once submerged the external surface of the driveline’s woven polyester velour into antibiotic solution we selected the location where the driveline would exit the skin. A subcutaneous path was created by using the tunneller tool pulling it to the preselected exit point. The LVAD driveline was then connected to the instrument and tunnelled into the path. Next dried and the driveline passed to the assistant who connected it to the controller. Retaining sutures were used for immobilization at the skin. (Video 6).
Video 6: Driveline tunnelization.
Outflow-graft implantation We placed a side clamp on the ascending aorta where the outflow graft would be placed. Once made a longitudinal arteriotomy, we sew the outflow graft to the aorta with a 4-0 polypropylene suture, reinforcing the sutures with bioglue surgical adhesive. We placed a sterile 18-gauge needle into the outflow graft between the pump and the outflow graft clamp. After all air bubbles were removed, the 18-gauge needle was removed, and the needle hole was oversewed. Finally, the outflow graft clamp and the aorta side clamp were released, and HeartWare pump speed gradually increased to achieve the desired flow. Under transoesophageal echocardiographic control, after complete resumption of mechanical ventilation, the ECMO support was gradually reduced (Video 7). Before the mini-sternal wound and the thoracotomy were closed according to the standard protocol, the pump was isolated from the pulmonary pleura by wrapping it in a sheet of Teflon. The patient was discharged from the hospital after almost one month. Now she is eligible for the transplant programme and is included in the waiting list for a donor heart (Video 8).
Video 7: Outflow-graft anastomosis and pump starting.
RESULTS Twenty-one patients were supported with the HeartWare® LVAD at our centre from January 2012 to December 2013. The same surgical technique (off-pump implantation, minimally invasive surgical
4
T. Bottio et al. / Multimedia Manual of Cardio-Thoracic Surgery
Table 1: Baseline characteristics of 21 patients implanted with the HeartWare LVAD in minimally invasive fashion (n = 21)
Video 8: Patient outcome.
approach) was applied. Twelve patients received the VAD with the aid of regional paravertebral block analgesia associated with mild general anaesthesia (low doses of short-half time anaesthetic drugs), while the remaining 9 patients were routinely anaesthetized (complete general anaesthesia). Thoracic paravertebral block analgesia allowed a faster postoperative weaning from the mild general anaesthesia associated, by providing adequate postoperative pain support without haemodynamic impairment and consequently fast weaning from the mechanical ventilation, making possible the extubation in the operating room (OR) in 9 of 12 patients (75%). The remaining patients were extubated in the intensive care unit 2–48 h later. Three patients required temporary right paracorporeal VAD support, with possible later on weaning and decannulation at almost 48-72 h after the LVAD implant (Table 1).
DISCUSSION LVADs have become an important option for the treatment of patients with advanced heart failure [7, 8]. Unfortunately, patients undergoing LVAD implantation still experience considerable perioperative and postoperative morbidity and mortality. Major non-device-associated complications are represented by RV failure, bleeding and prolonged ventilationrelated morbidity [9].
Right ventricular failure Early postoperative RV failure is associated with increased rates of short-term morbidity and mortality and still remains difficult to predict [10]. According to our experience, the following are the reasons that make this less invasive approach effective in the management of a possible RV failure. In case of unpredicted rapid evolution of RV failure after LVAD implantation in the OR, a good exposure of the pulmonary artery is available in the upper high ministernotomy, with possibility of rapid setting of temporary RV support without additional surgical difficulty or increased operative risk for the patient. The association of the minithoracotomy with the mini-high sternotomy allows preservation of mechanical respiratory physiology, with possible early extubation. This enables a rapid transit
Median age (mean years ± SD) Gender male (%) BSA (m2, mean ± SD) Diagnosis (%) Dilated cardiomyopathy Ischaemic cardiomyopathy Indications (%) Bridge to transplantation Bridge to candidacy Destination therapy Diabetes (%) Preop creatinine clearance (ml/min, mean ± SD) Preop chronic renal failure (%) COPD (%) PAP mean (mean mmHg ± SD) EF (%) TAPSE (%) INTERMACS (%) I II EUROSCORE II (mean ± SD) Preoperative ‘fast-ECMO’ support (%) ASA Class I/II/III/IV Perioperative ECMO support (%) Other procedures associated (%) Extubated in OR (%) Mechanical ventilation (h, mean ± SD) Length of stay (mean ± SD) ICU Ward Duration of inotropic support (h, mean ± SD) Postoperative RVAD support (%) Discharged home (%) ARF supported by CVVH (%) Stroke (%) Transplantation (%) Days of device (days, mean ± SD) Death (%)
49.25 ± 7.11 19/21 1.84 ± 0.11 16/21 5/21 21/21 0 0 6/21 67 ± 19 18/21 4/21 28 ± 11 18 ± 5 16 ± 4 8/21 13/21 23 ± 16 6/21 0/0/5/16 0 0 9/21 17.08 ± 11.79 7.3 ± 10.2 29.3 ± 40.0 143.2 ± 62.1 3/21 20/21 4/21 2/21 7/21 192 ± 115 1/21
BSA: body mass index; COPD: chronic obstructive pulmonary disease; Pulmonary arterial pressure; ECMO: extracorporeal membrane oxygenation; EF: ejection fraction; RVAD: right ventricular mechanical support; ARF: acute renal failure; ICU: intensive care unit.
from a pressure-positive mechanical ventilation towards a physiological pressure-negative spontaneous breathing, favouring downloading of the right ventricle frequently compromised in these patients. Additionally, the heart no-touch technique for left ventricle apex exposure (minithoracotomy) presents a decreased rate of arrhythmias and haemodynamic instability related to the heart manipulation, mandatory when in full sternotomy.
Bleeding Our policy is to establish ECMO support in the OR if cardiac manipulation is not tolerated. A single bolus of 5000 IU of intravenous heparin is used either for the ECMO and the pump implantation, in order to limit surgical bleeding and thus lower number of blood unit transfusion. The association of low doses of operative intravenous heparin to less-extensive mediastinal dissection reduces the risk and the degree of postoperative haemorrhage.
5
T. Bottio et al. / Multimedia Manual of Cardio-Thoracic Surgery
Furthermore, the surgical risk of a redo surgery for the patient treated with the LVAD as bridge to transplantation is limited since the vascular graft at reintervention is protected by the pericardium.
Prolonged ventilation-related morbidity Postoperative prolonged ventilation is one of the factors with the strongest mortality association risk in cardiac surgery [11]. Additionally, ventilator-associated pneumonia is the second most common hospital-acquired infection after blood stream infections, with a significant impact on patient morbidity and mortality [12]. Furthermore, mini-invasive cardiac surgery, compared with conventional full sternotomy cardiac surgery, is associated with decreased bleeding, blood product transfusion, sternal wound infection, scar dissatisfaction, ventilation time, intensive care unit stay, hospital length of stay and reduced time to return to normal activity, thereby resulting in better outcomes [13]. Conflict of interest: none declared.
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