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Jürgen Martin

Publications and source records attributed to Jürgen Martin.

7 recordsLinked to original sources
PubMed2006

Mechanical reliability of the Jarvik 2000 Heart.

BACKGROUND: Device failure is a limitation of permanent mechanical circulatory support. We studied the mechanical reliability of the Jarvik 2000 Heart, an axial flow pump with ceramic bearings designed to provide more than 10 years' durability. METHODS: The Jarvik 2000 Heart was implanted in 102 patients between April 2000 and December 2004. Eighty-three pumps with an abdominal driveline were implanted as a bridge-to-transplantation, and 19 with postauricular power supply as lifetime therapy. Eighteen pumps were recovered intact after clinical use and run continuously on the bench to further assess durability. RESULTS: No implantable component failure occurred either in patients or during bench testing. The cumulative pump run-time was 110 years: 59 years overall in vivo and 51 years in vitro. The mean support time for bridge-to-transplant recipients was 159 days, and for discharged lifetime-therapy recipients 551 days. Six recipients were supported moer than 2 years, with the longest ongoing approaching 5 years. External cables caused three system failures, with a 95% freedom from system failure at 4 years. Device malfunctions, related to external cables (9) and lack of a backup battery (1), caused no adverse consequences. Before introduction of noncorrosive, gold-plated stainless steel connectors, corrosion was observed on three connectors to the retroauricular power supply. CONCLUSIONS: The Jarvik 2000 Heart has had no implantable component failure. Meaningful durability data and failure mode can only be established by real-time testing in patients. The reliability and dependability of this device, in addition to the exchangeability of external components, give promise for long-term circulatory support in critically ill heart failure patients.

Equipment Failure Analysis↗
PubMed2005

Advanced heart failure: feasibility study of long-term continuous axial flow pump support.

AIMS: A lack of donor hearts has stimulated interest in using blood pumps to treat severe heart failure. We tested the hypothesis that a new continuous flow circulatory assist device could be employed safely to relieve symptoms of heart failure and evaluated the potential to prolong life. METHODS AND RESULTS: An intracardiac axial flow pump was implanted in 17 heart failure patients [idiopathic dilated (12), ischaemic (4), or amyloid cardiomyopathy (1)]. All were deemed ineligible for transplantation. Implantation of the device was by left thoracotomy (15) or median sternotomy (2). Power delivery was by a skull-mounted titanium pedestal. All patients survived surgery. None needed right ventricular support. There were three hospital deaths, two early from subdural haematoma and aortic thrombosis, one late after switching to transplantation. A total of 14 patients left hospital with a cumulative support-time of 15.9 years (median: 293 days, interquartile range: 286 days, 1-44 months). Actuarial 1-, 2-, and 3-year survivals were 56, 47, and 24%, respectively. There was no pump failure. Quality of life scores improved. Two superficial pedestal infections were successfully treated. Four patients had cerebral thrombo-embolism: two early events attributed to inadequate anticoagulation and two late with near-complete resolution. An improved anticoagulant regime addressed this problem. Late death occurred in five patients from battery disconnection, subdural haematoma, bowel ischaemia, respiratory failure, and after cardiac transplantation. CONCLUSION: Continuous flow blood pumps provided symptomatic relief of severe heart failure with high quality of life. Event-free survival reached 4 years. Analysis of adverse events led to improved management strategies. There is potential for widespread use of blood pumps in the community. A controlled trial is required.

Aged↗
PubMed2005

Anterior approach to implant the Jarvik 2000 with retroauricular power supply.

The retroauricular power supply of the Jarvik 2000 (Jarvik Heart Inc, New York, NY) left ventricular assist device is suitable for permanent support, as it is associated with fewer infections than conventional drivelines. Implantation through a left-lateral thoracotomy limits the performance of additional cardiac procedures. We describe a technique that used a sternotomy for the implantation of the Jarvik 2000 with retroauricular power supply in two patients. The retroauricular power supply of the Jarvik 2000 can be provided with an anterior approach, allowing full surgical access to the heart. If the outflow graft to the ascending aorta indeed reduces aortic stasis and thromboembolic events, the anterior approach with retroauricular power delivery might evolve into a standard procedure.

Aged↗
PubMed2002

Implantation of the permanent Jarvik-2000 left ventricular assist device: a single-center experience.

OBJECTIVES: We sought to evaluate the surgical results and effects of continuous support with the permanent Jarvik-2000 left ventricular assist device (LVAD). We report the early outcomes. BACKGROUND: A shortage of transplant donors necessitates the testing of alternative treatments. The Jarvik-2000 is an axial flow pump with a percutaneous retro-auricular power connector, designed for permanent use. METHODS: Patients with severe heart failure (HF), unsuitable for heart transplantation or conventional LVAD support, were offered implantation. The surgical approach included a left lateral thoracotomy. The device was implanted into the left ventricular apex on femoro-femoral bypass. It is set to allow pulsatile flow with an aortic valve opening. Anticoagulation is adjusted the same as for patients with a heart valve. RESULTS: Between May 2001 and August 2001, we implanted the Jarvik-2000 in two patients with dilated cardiomyopathy and in one with cardiac amyloidosis, all with severe HF (cardiac index 1.8 +/- 0.3 l/m(2) per min). One patient required preoperative inotropic support. All patients did well, with no repeat operations or infections. Patients received 4.3 +/- 3.2 packed red blood cells and were intubated at 14 +/- 3 h, and the intensive care unit stay was 7.0 +/- 0.5 days. The cardiac index increased from 3.7 +/- 1.5 l/min per m(2) at 8,000 rpm to 5.9 +/- 2.9 l/min per m(2) at 12,000 rpm. All patients currently have mild hemolysis not requiring transfusion. The following postoperative events were recorded: a transient ischemic attack with complete recovery, a short re-intubation due to ventricular arrhythmia, loss of consciousness with a battery change while standing, knee-joint effusion after ergometry training, a minor wound problem and a short hospital re-admission due to dehydration. Patients were discharged home after 49 +/- 7 days; one has returned to work. All quality-of-life scores have improved. CONCLUSIONS: The permanent Jarvik-2000 appears safe. It can be used for dilative or restrictive disease. The Jarvik-2000 might prove a valid option for the long-term treatment of patients with severe HF.

Amyloidosis↗
PubMed2002

Successful treatment of pulmonary hypertension with inhaled nitric oxide after pulmonary embolectomy.

Inhaled nitric oxide is an agent known to reduce pulmonary vascular resistance and prevent right heart failure. Pulmonary embolism is frequently followed by right heart failure and cardiogenic shock. Although successful treatment of patients with right ventricular failure caused by pulmonary embolism has been reported, clinical use of inhaled nitric oxide as an adjunct to surgical treatment is not in widespread use. We present a case of a 69-year-old woman with massive pulmonary embolism followed by right ventricular failure. After emergency operation, weaning from ventilation was prolonged. Pulmonary hypertension was decreased with low-dose inhaled nitric oxide, although pulmonary gas exchange did not improve. The patient was weaned successfully from ventilation 52 hours after operation and recovered completely. In a follow-up examination after 9 months, the patient is in healthy constitution with good cardiopulmonary function.

Administration, Inhalation↗
PubMedDate not supplied

Future horizons in surgical aortic valve replacement: lessons learned during the early stages of developing a transluminal implantation technique.

The aim of this study was to develop a heart valve prosthesis that could be transluminally inserted through the infrarenal aorta in pigs and the femoral artery in humans. Therefore, this valve prosthesis had to be foldable to a diameter of approximately 8 mm, self-expandable when released in the vascular system, and equipped with an anchoring mechanism. For implantation, a suitable catheter delivery system for insertion via the abdominal aorta in pigs also was designed. Furthermore, an operation method, including positioning of the catheter delivery system and deployment of the valved stent under fluoroscopic and echocardiographic control, was developed. A series of different prototypes of the valved stents and catheter delivery systems was produced to optimize design and handling. These prototypes were tested in vitro in a circulation model, and those showing satisfying hemodynamic properties were implanted in pigs as in vivo studies afterwards. The valved stents had a good hemodynamic function in vitro and in vivo with no more than a mild regurgitation or stenosis. Valve movements were satisfying, and the design proved to be generally feasible. However, positioning and anchoring were still difficult; some stents were tilted in the lumen or migrated after implantation.

Animals↗