Biomedical subjects

Alexander Siebel

Publications and source records attributed to Alexander Siebel.

4 recordsLinked to original sources

PubMed2005

Modified versus standard mechanical valved aortic conduit.

The aim of this study was to compare the hemodynamic characteristics and early clinical results of a commercially available standard aortic conduit with those of a modified valved composite graft, which consists of a mechanical valve prosthesis sewn into a vascular tube and placed in a supraannular position. The modified conduit was placed in 40 patients (group 1) and the standard conduit in another 40 patients (group 2). The early postoperative mortality rates (within 30 days after surgery) were 0% in group 1 and 5% (2 patients) in group 2; the difference was not statistically significant. The mean geometric orifice area of the valve prosthesis was significantly larger in group 1 than in group 2 (3.7 +/- 0.7 cm(2) versus 2.9 +/- 0.5 cm(2)). Early results showed a hemodynamic advantage of the modified conduit, with significantly lower transvalvular gradients.

Adult↗

PubMed2003

Valved stentless composite graft: clinical outcomes and hemodynamic characteristics.

BACKGROUND: The valved stentless composite graft has become well established in our hospital for replacement of the ascending aorta and aortic valve in elderly patients and those with contraindication for lifelong anticoagulation. This study was conducted to evaluate the postoperative hemodynamic characteristics and clinical outcomes after implantation of this device. METHODS: Between November 1998 and February 2001, 45 consecutive patients with a mean age of 69 years underwent implantation of a composite graft using a stentless valve prosthesis (Toronto SPV) incorporated in a collagen-coated Dacron tube (InterGard). The indication for surgery was aortic valve disease with an accompanying true aneurysm of the ascending aorta in 42 patients and a dissection of the aortic wall in 3 patients. Postoperative echocardiographic examinations were performed before discharge from the hospital and at the time of the follow-up. Mean follow-up duration was 18 months (range 3 to 30 months). RESULTS: There was no perioperative mortality. During follow-up, there were two noncardiac, nonvalve-related deaths. Echocardiographic evaluation before discharge and at follow-up demonstrated favorable hemodynamics of the valve prosthesis with mean transvalvular gradients of 8.5 +/- 2.9 mmHg and 8.0 +/- 3.1 mmHg, respectively. No regurgitation across the valve and no contact of the cusps with the Dacron tube were seen in any case. CONCLUSIONS: A stentless composite graft for replacement of the aortic valve and ascending aorta offers excellent hemodynamic results and is a suitable device for patients in whom anticoagulation should be avoided.

Adult↗

PubMed2003

Is extended aortic replacement in acute type A dissection justifiable?

BACKGROUND: The aim of this study was to evaluate the effectiveness of our surgical strategy for acute aortic dissection based on the extent of the dissection and the site of the entry, with special emphasis on resection of all dissected aortic segments if technically possible. METHODS: Between January 1995 and March 2001, 43 consecutive patients underwent operations for acute aortic dissection. In all patients the distal repair was performed under circulatory arrest without the use of an aortic cross-clamp. Fifteen patients underwent aortic arch replacement with additional reconstruction of supra-aortic vessels in 3 patients. Complete replacement of all dissected tissue could be achieved in 21 patients (group 1). Because of the distal extent of the dissection beyond the aortic arch, replacement of all the dissected tissue was not possible in 22 patients (group 2). RESULTS: Early mortality was 4.7% (2 patients), and the incidence of perioperative cerebrovascular events was 7.0% (3 patients). All of these events occurred in group 2 (p < 0.025). During the follow-up period of 6 years or less, 5 patients died, all from causes not related to the aorta or the aortic valve. A persisting patent false lumen was observed in 14 of the 36 surviving patients (39%). CONCLUSIONS: Extended replacement of the dissected ascending aorta and aortic arch can be done with good early and midterm results, even though it requires a complex surgical technique. Therefore we advocate complete replacement of the dissected parts of the aorta in all patients in whom this is technically possible.

Aged↗

PubMed2002

Stenosed kinking of the left main coronary artery combined with an aneurysm of the ascending aorta.

Stenosed kinking of the left main coronary artery is described in a 60-year-old man with an aneurysm of the ascending aorta and severe aortic valve insufficiency. An elective complete ascending aorta replacement using a valved composite graft was performed along with a shortening and direct implantation of the left main coronary artery. The right coronary artery was reimplanted as a Carrel-button.

Aortic Aneurysm↗