Biomedical subjects

Ulf Kjellman

Publications and source records attributed to Ulf Kjellman.

3 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↗

PubMed2006

Left ventricular reconstruction as an alternative to heart transplantation: a case report.

A 57-year-old man with dilated cardiomyopathy was referred to our institution to be assessed for heart transplantation. He had symptoms of severe heart failure and left ventricular dysfunction. We proposed surgical ventricular restoration (the Dor procedure) as an alternative to heart transplantation. The patient underwent successful surgery and an uneventful postoperative course. Pre- and postoperative investigations are presented. One year after surgery, the patient is in good clinical and functional condition. This case illustrates that surgical ventricular restoration can be an alternative to heart transplantation.

Cardiovascular Surgical Procedures↗

PubMed2002

Endograft therapy for diseases of the descending thoracic aorta: results in 43 high-risk patients.

PURPOSE: To report an initial experience with endovascular stent-graft implantation for diseases of the descending thoracic aorta in high-risk patients. METHODS: Forty-three patients (28 men; mean age 67 years, range 17-82) with 16 descending thoracic aortic dissections, 14 aneurysms, 7 contained ruptures, 3 mycotic aneurysms, 2 posttraumatic pseudoaneurysms, and an aneurysm of an anomalous right subclavian artery were treated between June 1999 and July 2001. Twenty-three (53%) patients were treated emergently. RESULTS: There were no conversions to open repair, but 3 (7%) patients died during the first 30 days (pneumonia, multiorgan failure, and acute bowel ischemia). Thirteen (30%) patients suffered 18 major complications (8 strokes, paraplegia in 3, respiratory insufficiency in 6, and 1 renal failure). Of 7 (16%) endoleaks detected in the early postoperative period, 3 required additional stents, while the other 4 were treated conservatively. Follow-up, which averaged 19 +/- 6 months (median: 13; range 0-34), was 100% complete. Five (12%) patients died: 3 of aortic rupture at 34, 47, and 139 days, respectively, and 2 from heart failure at 3 and 15 months, respectively. No late migration or endoleaks have been detected in the remaining 35 patients; however, 1 (2%) patient showed progressive aortic dissection proximal to the stent-graft. In all other cases, the size of the aneurysm or the false lumen was unchanged or diminished. CONCLUSIONS: Treatment of descending thoracic aortic diseases with an endovascular approach has acceptable early mortality and morbidity in high-risk patients. In selected cases, stent-grafts may afford the best therapy.

Adolescent↗