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CASE ANECDOTES, COMMENTS AND OPINIONS CircuLite left ventricular assist device explantation: A word of caution Stefan Klotz, MD, Efstratios I. Charitos, MD, Roza Meyer-Saraei, PhD, and Hans-Hinrich Sievers, MD From the Department of Cardiac and Thoracic Vascular Surgery, University of Luebeck, Germany.
The CircuLite Synergy Pocket Micro-pump (CircuLite Inc, Saddle Brook, NJ) is a small (AA battery-sized) blood pump that is implanted with an off-pump, right-sided minithoracotomy procedure. The inflow cannula consists of silicon reinforced with nitinol, with a length of 20.5 cm and an inner diameter of 6 mm, and has a Dacron (DuPont, Wilmington, DE) cuff on the tip made of titanium. The inflow cannula is implanted in the left atrium between the insertions of the right upper and lower pulmonary veins in a Seldinger technique and secured with 2 pursestring sutures. The proximal end of the inflow cannula is tunneled through the second intercostal space to exit the thorax in the area of the sub-cutaneous pocket. The inflow cannula is connected the pump, and a polytetrafluoroethylene outflow graft is anastomosed to the subclavian artery. The first implantation was performed in 2008. Indications for implantation were patients with heart failure who did not require full left ventricular assist device (LVAD) support. Several studies showed the clinical benefit of partial cardiac support, with maximal achievable flow of up to 3 liters/min.1–3 Conformité Européene Mark approval for this device was obtained in Europe in September 2012. In August 2013, CircuLite received a Synergy implantation stop order due to breaks in the inflow cannula, close to the connection to the pump. Some of these pumps had to be explanted for this reason. Other reasons were pump thrombosis or cardiac recovery. The inflow cannula is left in place during most explants. However, after more than 100 implantations worldwide, we are concerned regarding the explantation of the pump without removal of the inflow cannula.
Case report A 64-year-old man with ischemic cardiomyopathy after myocardial infarction and aortocoronary bypass grafting in 2001, with an ejection fraction of 20%, was referred to our department after implantation of a CircuLite Synergy Pocket Micro-pump in April 2013 at another institution. Because of numerous comorbidities (pulmonary hypertension, atrial fibrillation, obesity, polyneuropathy, insulin depended diabetes mellitus, compensated renal failure, chronic obstructive pulmonary disease), a
minimally invasive approached was decided, and the CircuLite pump and not a full-support LVAD was implanted. The patient’s peri-operative course was complicated with long-term ventilation requiring tracheotomy, cardiopulmonary reanimation, and recurrent seroma buildup in the subcutaneous pump pocket. The patient was not able to cope with the driveline and the external components, such as the controller and batteries, and requested explantation of the pump after 4 months of support in August 2013. The pump was removed, the outflow graft was over sewn close to the subclavian artery, and the inflow cannula was left in place with a stopcock at the end. In November 2013, the patient was referred to our department with signs of an infection in the former pump pocket. Antibiotic therapy was initiated, but a day later the inflow cannula begun protruding out of the skin (Figure 1A). Transesophageal echocardiography revealed a floating thrombus exceeding 4 cm in length, starting at the tip of the inflow cannula in the left atrium (Figure 1B; Video, available on the jhltonline.org Web site), even though the patient received aspirin and warfarin due to atrial fibrillation. A right-sided repeat thoracotomy was performed, and the inflow cannula was prepared until the insertion into the left atrium. After cutting the pursestring sutures, the inflow cannula could be removed in toto, with the adhered thrombus still attached (Figure 1C). The cannula insertion site in the left atrium was sewn with pledged sutures. The patient’s postoperative course was prolonged because of transient renal failure and pneumonia.
Discussion This case report demonstrates a possible complication explanting a CircuLite pump while leaving the inflow cannula in place. Owing to the turbulence at the titanium/Dacron tip of the inflow cannula, probably combined with blood stasis, left atrium thrombus formation is possible despite anticoagulation. A later explantation of the inflow cannula in these heart failure patients is a risky undertaking, as in the patient we describe. If a pump has to be explanted and the inflow cannula will be left in place, the tip should be sealed, such as with an Amplatzer occluder (St Jude Medical, St Paul, MN), as described by Sainte et al,4 and Schmack et al.5
Disclosure statement None of the authors has a financial relationship with a commercial entity that has an interest in the subject of the presented manuscript or other conflicts of interest to disclose.
1053-2498/$ - see front matter r 2014 International Society for Heart and Lung Transplantation. All rights reserved. http://dx.doi.org/10.1016/j.healun.2014.01.002
452
The Journal of Heart and Lung Transplantation, Vol 33, No 4, April 2014
Figure 1 (A) The inflow cannula is seen protruding out of the skin. (B) Ultrasound imaging shows a 4.4-cm-long thrombus floating in the left atrium. (C) The inflow cannula was removed with the adhered thrombus at the tip of the cannula.
Supplementary material A supplementary video is available in the online version of this article at jhltonline.org.
References 1. Klotz S, Meyns B, Simon A, et al. Partial mechanical long-term support with the CircuLite Synergy pump as bridge-to-transplant in congestive heart failure. Thorac Cardiovasc Surg 2010;58(Suppl 2): S173-8.
Diffuse rhabdomyomatosis presenting as infantile hypertrophic cardiomyopathy Sabrina Law, MD,a Terrence Chun, MD,a and Raj Kapur, MDb From the aDivision of Pediatric Cardiology; and the bDivision of Pathology, Seattle Children’s Hospital, Seattle, Washington.
Diffuse ventricular thickening is often attributed to hypertrophic cardiomyopathy (HCM).1 We present a case of HCM with an unusual pathologic diagnosis. A 2-hour-old neonate presented with supraventricular tachycardia (SVT). Echocardiography demonstrated severe biventricular thickening with no outflow tract obstruction and normal function. Within 2 weeks, she developed low cardiac output with left ventricular outflow tract obstruction (3.7 m/s), and a doubling of interventricular septal wall thickness (diastolic dimension 2.02 cm, z-score ¼ 24.7, previously 1.1 cm, z-score ¼ 10.7). Gene testing was negative for Noonan syndrome and sarcomeric hypertrophic cardiomyopathy (HCM), as was screening for inborn errors of
2. Meyns B, Klotz S, Simon A, et al. Proof of concept: hemodynamic response to long-term partial ventricular support with the synergy pocket micro-pump. J Am Coll Cardiol 2009;54:79-86. 3. Meyns BP, Simon A, Klotz S, et al. Clinical benefits of partial circulatory support in New York Heart Association class IIIB and early class IV patients. Eur J Cardiothorac Surg 2011;39:693-8. 4. Sainte S, Gewillig M, Droogne W, et al. Explantation of a CircuLite left ventricular assist device without removal of the inflow cannula: how to do it? Interact Cardiovasc Thorac Surg 2013, http://dx.doi.org/10.1093/ icvts/ivt488: [E-pub ahead of print]. 5. Schmack B, Gorenflo M, Rengier F, Ruhparwar A. Extempore interventional closure of a broken CircuLite Synergy micropump inflow graft defect. J Heart Lung Transplant 2013;32:1140-1.
metabolism. Clinical examination was negative for features of tuberous sclerosis complex (TSC). Abdominal and brain magnetic resonance images were normal. The patient had recurrent hemodynamically significant episodes of SVT that worsened despite multiple antiarrhythmic medications. Intracardiac electrophysiology study revealed a retrograde-conducting, right-sided accessory pathway, which was ablated successfully. An intermittently conducting, concealed, left-sided pathway was not ablated. Due to complete atrioventricular block, she received a permanent dual-chamber pacemaker 10 days later. Shortly thereafter, she developed periods of pacemaker-mediated tachycardia, where ventricular pacing was conducted retrograde via accessory pathway to the atrium, tracked by the device, and then re-propagated back to the ventricle. To prevent this, the device was programmed to asynchronous (VVI) pacing. The patient then had cardiovascular collapse requiring extracorporeal cardiopulmonary resuscitation (ECPR), followed by progressive ventricular dysfunction, and was listed for transplantation. She developed new pre-excitation
CASE ANECDOTES, COMMENTS AND OPINIONS CircuLite left ventricular assist device explantation: A word of caution Stefan Klotz, MD, Efstratios I. Charitos, MD, Roza Meyer-Saraei, PhD, and Hans-Hinrich Sievers, MD From the Department of Cardiac and Thoracic Vascular Surgery, University of Luebeck, Germany.
The CircuLite Synergy Pocket Micro-pump (CircuLite Inc, Saddle Brook, NJ) is a small (AA battery-sized) blood pump that is implanted with an off-pump, right-sided minithoracotomy procedure. The inflow cannula consists of silicon reinforced with nitinol, with a length of 20.5 cm and an inner diameter of 6 mm, and has a Dacron (DuPont, Wilmington, DE) cuff on the tip made of titanium. The inflow cannula is implanted in the left atrium between the insertions of the right upper and lower pulmonary veins in a Seldinger technique and secured with 2 pursestring sutures. The proximal end of the inflow cannula is tunneled through the second intercostal space to exit the thorax in the area of the sub-cutaneous pocket. The inflow cannula is connected the pump, and a polytetrafluoroethylene outflow graft is anastomosed to the subclavian artery. The first implantation was performed in 2008. Indications for implantation were patients with heart failure who did not require full left ventricular assist device (LVAD) support. Several studies showed the clinical benefit of partial cardiac support, with maximal achievable flow of up to 3 liters/min.1–3 Conformité Européene Mark approval for this device was obtained in Europe in September 2012. In August 2013, CircuLite received a Synergy implantation stop order due to breaks in the inflow cannula, close to the connection to the pump. Some of these pumps had to be explanted for this reason. Other reasons were pump thrombosis or cardiac recovery. The inflow cannula is left in place during most explants. However, after more than 100 implantations worldwide, we are concerned regarding the explantation of the pump without removal of the inflow cannula.
Case report A 64-year-old man with ischemic cardiomyopathy after myocardial infarction and aortocoronary bypass grafting in 2001, with an ejection fraction of 20%, was referred to our department after implantation of a CircuLite Synergy Pocket Micro-pump in April 2013 at another institution. Because of numerous comorbidities (pulmonary hypertension, atrial fibrillation, obesity, polyneuropathy, insulin depended diabetes mellitus, compensated renal failure, chronic obstructive pulmonary disease), a
minimally invasive approached was decided, and the CircuLite pump and not a full-support LVAD was implanted. The patient’s peri-operative course was complicated with long-term ventilation requiring tracheotomy, cardiopulmonary reanimation, and recurrent seroma buildup in the subcutaneous pump pocket. The patient was not able to cope with the driveline and the external components, such as the controller and batteries, and requested explantation of the pump after 4 months of support in August 2013. The pump was removed, the outflow graft was over sewn close to the subclavian artery, and the inflow cannula was left in place with a stopcock at the end. In November 2013, the patient was referred to our department with signs of an infection in the former pump pocket. Antibiotic therapy was initiated, but a day later the inflow cannula begun protruding out of the skin (Figure 1A). Transesophageal echocardiography revealed a floating thrombus exceeding 4 cm in length, starting at the tip of the inflow cannula in the left atrium (Figure 1B; Video, available on the jhltonline.org Web site), even though the patient received aspirin and warfarin due to atrial fibrillation. A right-sided repeat thoracotomy was performed, and the inflow cannula was prepared until the insertion into the left atrium. After cutting the pursestring sutures, the inflow cannula could be removed in toto, with the adhered thrombus still attached (Figure 1C). The cannula insertion site in the left atrium was sewn with pledged sutures. The patient’s postoperative course was prolonged because of transient renal failure and pneumonia.
Discussion This case report demonstrates a possible complication explanting a CircuLite pump while leaving the inflow cannula in place. Owing to the turbulence at the titanium/Dacron tip of the inflow cannula, probably combined with blood stasis, left atrium thrombus formation is possible despite anticoagulation. A later explantation of the inflow cannula in these heart failure patients is a risky undertaking, as in the patient we describe. If a pump has to be explanted and the inflow cannula will be left in place, the tip should be sealed, such as with an Amplatzer occluder (St Jude Medical, St Paul, MN), as described by Sainte et al,4 and Schmack et al.5
Disclosure statement None of the authors has a financial relationship with a commercial entity that has an interest in the subject of the presented manuscript or other conflicts of interest to disclose.
1053-2498/$ - see front matter r 2014 International Society for Heart and Lung Transplantation. All rights reserved. http://dx.doi.org/10.1016/j.healun.2014.01.002
452
The Journal of Heart and Lung Transplantation, Vol 33, No 4, April 2014
Figure 1 (A) The inflow cannula is seen protruding out of the skin. (B) Ultrasound imaging shows a 4.4-cm-long thrombus floating in the left atrium. (C) The inflow cannula was removed with the adhered thrombus at the tip of the cannula.
Supplementary material A supplementary video is available in the online version of this article at jhltonline.org.
References 1. Klotz S, Meyns B, Simon A, et al. Partial mechanical long-term support with the CircuLite Synergy pump as bridge-to-transplant in congestive heart failure. Thorac Cardiovasc Surg 2010;58(Suppl 2): S173-8.
Diffuse rhabdomyomatosis presenting as infantile hypertrophic cardiomyopathy Sabrina Law, MD,a Terrence Chun, MD,a and Raj Kapur, MDb From the aDivision of Pediatric Cardiology; and the bDivision of Pathology, Seattle Children’s Hospital, Seattle, Washington.
Diffuse ventricular thickening is often attributed to hypertrophic cardiomyopathy (HCM).1 We present a case of HCM with an unusual pathologic diagnosis. A 2-hour-old neonate presented with supraventricular tachycardia (SVT). Echocardiography demonstrated severe biventricular thickening with no outflow tract obstruction and normal function. Within 2 weeks, she developed low cardiac output with left ventricular outflow tract obstruction (3.7 m/s), and a doubling of interventricular septal wall thickness (diastolic dimension 2.02 cm, z-score ¼ 24.7, previously 1.1 cm, z-score ¼ 10.7). Gene testing was negative for Noonan syndrome and sarcomeric hypertrophic cardiomyopathy (HCM), as was screening for inborn errors of
2. Meyns B, Klotz S, Simon A, et al. Proof of concept: hemodynamic response to long-term partial ventricular support with the synergy pocket micro-pump. J Am Coll Cardiol 2009;54:79-86. 3. Meyns BP, Simon A, Klotz S, et al. Clinical benefits of partial circulatory support in New York Heart Association class IIIB and early class IV patients. Eur J Cardiothorac Surg 2011;39:693-8. 4. Sainte S, Gewillig M, Droogne W, et al. Explantation of a CircuLite left ventricular assist device without removal of the inflow cannula: how to do it? Interact Cardiovasc Thorac Surg 2013, http://dx.doi.org/10.1093/ icvts/ivt488: [E-pub ahead of print]. 5. Schmack B, Gorenflo M, Rengier F, Ruhparwar A. Extempore interventional closure of a broken CircuLite Synergy micropump inflow graft defect. J Heart Lung Transplant 2013;32:1140-1.
metabolism. Clinical examination was negative for features of tuberous sclerosis complex (TSC). Abdominal and brain magnetic resonance images were normal. The patient had recurrent hemodynamically significant episodes of SVT that worsened despite multiple antiarrhythmic medications. Intracardiac electrophysiology study revealed a retrograde-conducting, right-sided accessory pathway, which was ablated successfully. An intermittently conducting, concealed, left-sided pathway was not ablated. Due to complete atrioventricular block, she received a permanent dual-chamber pacemaker 10 days later. Shortly thereafter, she developed periods of pacemaker-mediated tachycardia, where ventricular pacing was conducted retrograde via accessory pathway to the atrium, tracked by the device, and then re-propagated back to the ventricle. To prevent this, the device was programmed to asynchronous (VVI) pacing. The patient then had cardiovascular collapse requiring extracorporeal cardiopulmonary resuscitation (ECPR), followed by progressive ventricular dysfunction, and was listed for transplantation. She developed new pre-excitation
