Ann Thorac Surg 2004;78:1818-1820
© 2004 The Society of Thoracic Surgeons
Case report
Intercontinental LVAS Patient Transport
Michel Haddad, MDa,
Roy G. Masters, MD*,a,
Paul J. Hendry, MDa,
Akihiko Kawai, MDd,
John P. Veinot, MDb,
Gilbert Lavallee, RNc,
Tofy V. Mussivand, DEngc
a Division of Cardiac Surgery, Ottawa, Ontario, Canada
b Division of Pathology, Ottawa, Ontario, Canada
c Division of Cardiovascular Devices, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
d Division of Cardiovascular Surgery, Tokyo Women's Medical University, Tokyo, Japan
Accepted for publication July 17, 2003.
* Address reprint requests to Dr Masters, University of Ottawa Heart Institute, 40 Ruskin St, Ottawa, Ontario, Canada K1Y-4W7
rmasters{at}ottawaheart.ca
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Abstract
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Mechanical circulatory support is currently indicated for patients with cardiac insufficiency as a bridge to transplantation or as a bridge to recovery. These systems continue to evolve and improve, and many patients (after they are stabilized) are now able to be discharged from the hospital. This article reports our experience with the intercontinental transportation of a patient while being supported with a Novacor left ventricular assist system (WorldHeart Corp, Ottawa, Canada). While in Japan, the Canadian patient suffered a myocardial infarction and despite coronary artery bypass grafting, the patient remained in a low cardiac output state. After implantation of the left ventricular assist system in Japan, the patient was stabilized and transported by a commercial airline to Canada where he underwent successful heart transplantation.
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Introduction
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Mechanical circulatory support systems were initially introduced in the late 1960s as a mean to support postcardiotomy shock patients [1, 2]. Experience with these devices has increased since that time, and currently these systems are also indicated for patients in end-stage heart failure as a bridge to transplantation, or in select patients as a bridge to recovery [3–6]. After being stabilized, many patients are now discharged from the hospital while awaiting transplantation or recovery to occur. In this report we describe our experience with the international transfer of a patient supported with a left ventricular assist system (LVAS) by a routine commercial airline from Japan to Canada in order to receive a heart transplant.
The patient is a 26-year-old, previously healthy male from the province of Alberta, Canada with no known coronary disease risk factors. He had recently relocated to Japan to work as a teacher. While in Japan he was admitted to a Tokyo community hospital in November 2000 with a 1-week history of malaise and dyspnea, and he was diagnosed with a large anterior wall myocardial infarction. However, due to persistent hemodynamic instability he was transferred to a tertiary care hospital. An echocardiogram demonstrated severe left ventricular dysfunction with an ejection fraction of 15%. In addition, a 5 cm endocardial left ventricular thrombus was discovered. Further evaluation revealed an elevated platelet count (800,000/mm3), which led to the eventual diagnosis of idiopathic thrombocytosis. Coronary angiography demonstrated a complete occlusion of the proximal left anterior descending coronary artery with normal right and circumflex systems. The patient subsequently underwent emergency coronary artery bypass grafting using a reversed saphenous vein to the left anterior descending coronary artery and removal of the left ventricular thrombus. Intraoperatively, the left anterior descending coronary artery was noted to be filled with fresh thrombus. The patient required inotropic agents, extracorporeal membrane oxygenation, and an intraaortic balloon pump to be weaned from cardiopulmonary bypass.
Postoperatively, the patient's cardiac function remained poor, and the University of Ottawa Heart Institute was contacted regarding management options as heart transplantation was not available in Japan. A decision was made to stabilize the patient with a mechanical circulatory device and transfer him to Canada for further management and possible transplantation. Subsequently, a Novacor LVAS (WorldHeart Corp, Ottawa, Canada) was successfully implanted in Japan in December 2000. The LVAS was implanted intraperitoneally to avoid abdominal wall bleeding complications. The inflow cannula was connected to the left ventricular apex, and the outflow cannula was anastomosed to the ascending aorta in an end-to-side fashion. The patient was maintained on aspirin, dipyridamole, and warfarin (target international normalized ratio, approximately 3). Inotropic agents, extracorporeal membrane oxygenation and intraaortic balloon pump support were weaned and discontinued and the patient was started on amiodarone for refractory arrhythmias. The patient's platelet count remained elevated (1,000,000/mm [3], and he was reopened twice for bleeding. The patient remained intact neurologically, was supplemented with total parenteral nutrition, and transiently required continuous veno-venous hemodialysis for renal failure.
The patient slowly improved and approximately 2 months after the LVAS implantation, he was transferred to the University of Ottawa Heart Institute on a regular commercial flight. Before the international transfer, a detailed plan was developed for the mission. The Canadian and Japanese diplomatic communities in Ottawa, Canada and Tokyo, Japan were contacted in order to obtain the required visas. In addition, the commercial airline (Air Canada), and airport authorities on both sides of the pacific were engaged to collaboratively facilitate the logistics of this international medical evacuation. The Alberta ministry of health agreed to provide all the expenses for the device insertion in Japan, transportation, and transplantation in Ottawa, Ontario, Canada.
A medical team was assembled for the mission. The 3-member team consisted of a senior LVAS operator and perfusionist, a MediVac trained registered nurse, and a MediVac trained respiratory therapist. The team flew to Japan in order to evaluate the medical status of the patient and ensure his stability and suitability for the long journey. The patient was de-conditioned and bedridden, but he was medically stable. Authorization for the transfer was obtained from the receiving Canadian surgeon once the team was satisfied with their ability to safely transfer the patient to Canada. Before departure, the LVAS power consumption was assessed against the patient's pump rate of 112 beats per minute and an output of 6.7 L per minute. The physiologic alarm limits on the LVAS external controller were set for a high performance so as to prompt condition alerts on moderate changes. Thresholds were set for a minimum pump output of 4.0 L, a minimum stroke volume of 40 mL, and a maximum residual volume of 15 mL. These indicators were programmed onto two additional backup controllers. Technical support was received by the Baxter and Novacor's Japanese representatives for the provision of three nickel-cadmium chargers for the preflight optimization of all return direct current power sources. Six system specific nickel-cadmium power packs with an expected nominal capacity of 24 hours were used as the primary LVAS power supply during the transfer.
The stretcher-bound patient was escorted to Narita International Airport in Tokyo by the LVAS senior operator, the patient's parent, and an attending staff physician from Tokyo Women's Hospital. The patient and perfusionist were joined by the rest of the MediVac team at the airport. Japanese direct current power sources were utilized for the first 3 hours of the trip. Analyses of electromagnetic emissions interference on aircraft controls associated with on board LVAS operations had already been previously described and reported for several types and geometry of aircraft [9]. Before departure from Tokyo to Toronto on an AirBus A340 and later from Toronto to Ottawa on an AirBus A320, flight staff was questioned before take off and no evidence of electromagnetic interference was detectable from the flight deck according to the flight staff. Two rows of seats were reserved at the back of the plane. The patient was not isolated from the rest of the passengers. He remained on a stretcher throughout the flight due to his severe de-conditioned state. A wheelchair was used to move the patient on board the plane. Intravenous lactated ringers were maintained at a rate of 30 mL per hour. A mild sedative was used to calm the patient, who slept for most of the trip. The international flight was uneventful with the exception of a 10% to 15% reduction in peak fill rates after the first 2 hours of flight, which was attributed to a heightened insensible loss and remedied with an increase in the hourly intravenous fluid infusion rate. Airport authorities were kept informed of the team's progress, and they provided transportation assistance on arrival to the various airports. Adverse weather conditions encountered at the Canadian point of entry (Toronto) resulted in a 4-hour layover at the airport during which time the LVAS was powered from an alternating current source. The second flight, from Toronto to Ottawa, and subsequent land transport to our hospital completed the 21.5 hours of travel time, which was well tolerated by the patient. In Ottawa the patient continued to improve, and he was investigated for thrombocytosis, which was determined to be idiopathic in nature. Here the patient was maintained on aspirin, clopidogrel, and warfarin (target international normalized ratio, approximately 3.0). Approximately 1 month after his transfer to Canada, the patient subsequently underwent a successful orthotopic cardiac transplantation with a transplanted heart from a 31-year-old donor. After intense rehabilitation, he was discharged home in good condition 4 months after transplantation, and he continues to do well to date.
The explanted heart showed a healing large transmural anteroseptal left ventricular myocardial infarct. Both left ventricular papillary muscles and the right ventricle walls showed subendocardial infarction. The left anterior descending coronary artery was subtotally occluded with a fibromyxoid intimal tissue typical of an organizing thrombus. No underlying native arteriosclerosis was seen in the left anterior descending coronary artery or in any other coronary artery. The LVAS conduits were uncomplicated.
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Comment
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One of the goals of the current generation of circulatory support devices is to allow patients to be discharged home so they can resume relatively normal lifestyles. To accomplish this goal, patients may have to be transported over great distances. Patient mobility should increase with increasing familiarity with these devices.
These devices have markedly improved during the years in terms of both versatility and reliability. The indications for their use have expanded, and many patients have been successfully supported to transplantation or to recovery of the native heart [5, 6]. However, for these devices to gain widespread acceptance as an established treatment option for end-stage heart failure, they need to be effective, reliable, and portable [7, 8]. Initially, patients connected to mechanical support devices were confined to an intensive care unit until either a transplant or a recovery occurred. As the devices evolved, it became possible to transfer these patients to a step down unit or a ward, and most recently it has become possible to discharge these patients from hospitals. This has provided an improvement in the patient's quality of life. This article demonstrates the reliability and portability of one of these devices, the Novacor LVAS (WorldHeart Corp), such that it is possible for these patients to safely travel long distances, even on routine commercial flights. We believe there have only been a few published reports documenting the long distance transfer of patients while being supported with an LVAS, only one of which was with a Novacor system (WorldHeart Corp) [9, 10]. We also believe that this trip constituted the longest reported transport of such a patient (21.5 hours) using a commercial flight; the previous longest trip was for 17 hours using a chartered flight [10].
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References
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- Spencer FC, Eisman B, Trinkle JK, Bodd NP. Assisted circulation for cardiac failure following intracardiac surgery with cardiorespiratory bypass. J Thorac Cardiovasc Surg. 1965;49:56–73[Medline]
- Debakey ME. Left ventricular bypass pump or cardiac assistance: clinical experience. Am J Cardiol. 1971;27:3–11[Medline]
- Samuels LE, Holmes EC, Thomas MP, et al. Management of acute cardiac failure with mechanical assist: experience with the BIOMED BVS 5000. Ann Thorac Surg. 2001;71(Suppl 3):S67–72[Abstract/Free Full Text]
- Acker MA. Mechanical circulatory support for patients with acute-fulminant myocarditis. Ann Thorac Surg. 2001;71(Suppl 3):S73–76[Abstract/Free Full Text]
- Copeland JG, Smith RG, Arabia FA, et al. Comparison of the Cardiowest total artificial heart, the Novacor left ventricular assist system, and the Thoratec ventricular assist system in the bridge to transplantation. Ann Thorac Surg. 2001;71(Suppl 3):S92–97[Medline]
- El-Banayosy A, Korfer R, Arusoglu L, et al. Device and patient management in a bridge to transplant setting. Ann Thorac Surg. 2001;71(Suppl 3):S98–102[Abstract/Free Full Text]
- Hendry PJ, Mussivand TV, Masters RG, et al. The HeartSaver left ventricular assist device: an update. Ann Thorac Surg. 2001;71(Suppl 3):S166–170[Abstract/Free Full Text]
- Mehta SM, Pae WE, Rosenberg G, et al. The Lion Heart LVD-2000: a completely implantable left ventricular assist device for chronic circulatory support. Ann Thorac Surg. 2001;71(Suppl 3):S162–165[Abstract/Free Full Text]
- Pristas JM, et al. Flight experience with the Novacor LVAS. ASAIO J. 2001;47:266–271[Medline]
- Matsuwaka R, et al. Overseas transport of a patient with an extracorporeal left ventricular assist device. Ann Thorac Surg. 1995;59:522–523[Abstract/Free Full Text]
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Abstract
Introduction
