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- Granfeldt, Hans, et al.
(författare)
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The Linkoping-Lund surgical experience with the HeartMate left ventricular assist system
- 1995
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Ingår i: Annals of Thoracic Surgery. - 1552-6259. ; 59:Suppl. 1, s. 52-55
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Tidskriftsartikel (refereegranskat)abstract
- Four transplant candidates fulfilling the Food and Drug Administration criteria for a permanent left ventricular assist device received a pneumatic HeartMate system as a bridge to heart transplantation. All patients survived and were fully rehabilitated at the time of transplantation, which was carried out 2 to 6 months after the initial operation. There were no major complications associated with the procedures. We are impressed by the effectiveness and safety of the device.
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- Lönn, Urban
(författare)
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A minimally invasive axial blood flow pump : an experimental and clinical study
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The first aim of this thesis was to evaluate a new minimally invasive axial blood flow pump for treatment of patients needing circulatory support after open heart surgery. This system, the Hemopump temporary cardiac assist device, is a very small catheter mounted intracorporeal pump, which is introduced transvalvularly into the left ventricle. The pump can be inserted either through the femoral artery or directly through a graft sutured to the ascending aorta. In an experimental model, the flow capacity of three different designs of the system was investigated. Flow capacity varied between 2.0 and 4.5 liters per minute, depending on the working conditions for the different pump models. Twenty,four patients were treated for post,cardiotomy heart failure. Fourteen patients (58 %) were weaned from the device and later discharged from the hospital. In a subgroup of these patients (54%) where early intervention was instituted, the survival rate was 85%. The pump proved to be an effective tool for unloading a failing left ventricle with preservation of multi-organ perfusion. A clinical protocol was established for postoperative management. The Hemopump was easy to adapt to the clinical setting, and device~ related complications were few.The second aim was to develop a new less invasive procedure for CABG, avoiding the need for cardio~pulmonary bypass during these procedures. First an animal trial was performed as a feasibility study. In combination with the administration of a short~acting ~~blocker, esmolol, this method enabled precise coronary bypass surgery. When results became consistent a small pilot study was done on five patients showing that this was a reproducible technique. Finally a prospective randomized trial comparing this technique with conventional bypass surgery was carried out. The Hemopump supported bypass surgery did not prolong the procedure, did not require a longer time on circulatory support and bleeding was less. Postoperative enzyme levels indicated that ischemic insult to the myocardium was less than with conventional surgery.In summary, this minimally invasive axial blood flow pump proved to be a powerful left ventricular assist system enabling a less invasive approach during conditions where circulatory support is needed.
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- Peterzén, Bengt, et al.
(författare)
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Anesthetic management of patients undergoing coronary artery bypass grafting with the use of an axial flow pump and a short-acting beta-blocker
- 1999
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Ingår i: Journal of cardiothoracic and vascular anesthesia. - 1053-0770. ; 13:4, s. 431-436
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To describe the clinical protocol regarding monitoring, pharmacologic interventions, and postoperative care during and after coronary artery bypass grafting (CABG) on the beating heart with an axial flow pump and a short-acting β-blocker. Design: A retrospective study. Setting: A university hospital. Participants: Seventeen patients scheduled for elective CABG. Interventions: Invasive monitoring was performed with either a standard pulmonary artery catheter (PAC) or a surgically placed PAC. An axial flow pump was inserted through a graft sutured to the ascending aorta. A short-acting β-blocker was administered to decrease the motion of the heart and make conditions for CABG adequate and safe. Measurements and main results: Compared with baseline measurements, there were significant decreases in mean arterial blood pressure, mixed venous oxygen saturation, and right ventricular ejection fraction during maximal axial flow pump support and β-blockade. No significant change in heart rate was observed at this time. Hemodynamic variables were normalized in the intensive care unit. All patients were separated from the Hemopump without inotropic support, and values of troponin-T, aspartate aminotransferase, and alanine aminotransferase were low postoperatively. All patients survived and were discharged from the hospital. Conclusion: The anesthetic protocol for patients undergoing surgery with a beating heart and the combined use of an axial flow pump and a short-acting β-blocker is outlined. Multiple-vessel CABG on the beating heart was performed with maintenance of an acceptable hemodynamic situation.
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| 9. |
- Peterzén, Bengt, et al.
(författare)
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Postoperative management of patients with Hemopump support after coronary artery bypass grafting
- 1996
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Ingår i: The Annals of thoracic surgery. - 0003-4975. ; 62:2, s. 378-385
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Tidskriftsartikel (refereegranskat)abstract
- Background In this study, we describe postoperative monitoring, pharmacologic therapy, and hemodynamic responses in patients receiving Hemopump support after postcardiotomy heart failure. Methods The Hemopump was used in 24 patients with severe left ventricular dysfunction after coronary artery bypass grafting. Results Fourteen patients (58%) were weaned from the Hemopump. Low to moderate doses of a combination of catecholamines, phosphodiesterase inhibitors, vasodilators, and vasoconstrictors were required to optimize Hemopump function and left ventricular unloading. Mean arterial blood pressure, mixed venous oxygen saturation, and urinary output were the most important therapy guidelines. Conclusions Together with our clinical protocol, the Hemopump effectively unloaded the failing ventricle while maintaining vital-organ perfusion. Doses of vasoactive drugs could be kept low. This approach to treatment provides good conditions for recovery of the stunned myocardium.
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| 10. |
- Wulff, John, et al.
(författare)
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Flow characteristics of the Hemopump : an experimental in vitro study.
- 1997
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Ingår i: Annals of Thoracic Surgery. - 0003-4975 .- 1552-6259. ; 63:1, s. 162-166
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The Hemopump (DLP/Medtronic) has been in clinical use for about 7 years. There is still no adequate way of determining actual output from the three available pump systems in the clinical situation. If the pump is completely stopped during weaning from the device, there is a possibility of back-leakage through the pump, endangering the patient from regurgitation into the left ventricle. It can also make it more difficult to judge the recovery of heart function because of a volume load of the left ventricle. The aim of this study was to evaluate in a standardized, experimental in vitro model the output from three different-sized Hemopump catheters at various pressure levels and to quantify the back-flow through the pumps.METHODS: The Hemopump models were tested in an in vitro study regarding total outflow at various speeds at three pressure levels. The back-flow through the pumps was also measured with the pumps at a complete stop.RESULTS: The outflow from the Hemopumps ranged from 0.4 to 4.5 L/min, depending on which pump and speed were used. Variations in total output, depending on speed and various pressure settings, could be up to 0.4 L/min. Back-flow through the pump into the left ventricle may be as great as 1.6 L/min.CONCLUSIONS: The flow outputs from the different Hemopump models were reproducible over time and were closely related to the resistance of the model. The Hemopump, if not running, can induce substantial regurgitation through the pump into the left ventricle.
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