Planiks disk valve prostheses

1996 ◽  
Vol 69 (3) ◽  
pp. 382-389
Author(s):  
Yu. P. Ostrovskii
Keyword(s):  
Disk Valve ◽  
Valve Prostheses

Thrombolytic Treatment of Acute Thrombotic Obstruction with Disk Valve Prostheses: Experience with 26 Cases

1987 ◽  
Vol 13 (02) ◽  
pp. 201-205 ◽  
Author(s):  
Marie-Francoise Roudaut ◽  
Louis Ledain ◽  
Raymond Roudaut ◽  
Pierre Besse ◽  
Michel Boisseau
Keyword(s):  
Thrombolytic Treatment ◽  
Disk Valve ◽  
Valve Prostheses

Comparative Study of the Amount of Backflow Produced by Four Types of Aortic Valve Prostheses

1984 ◽  
Vol 106 (1) ◽  
pp. 66-71 ◽  
Author(s):  
H. N. Sabbah ◽  
P. D. Stein
Keyword(s):  
Aortic Pressure ◽  
Low Cardiac Output ◽  
Prosthetic Valves ◽  
Mechanical Valves ◽  
Disk Valve ◽  
Pump Rate ◽  
Valve Leakage ◽  
Clinically Significant ◽  
Valve Prostheses ◽  
Mean Aortic Pressure

To determine the extent of backflow encountered with currently used prosthetic valves, four types of aortic valves with comparable orifice diameters were tested in a pulse duplicating system. These were a Hancock porcine valve, a Lillehei-Kaster pivoting disk valve, a St. Jude bileaflet valve and a Bjo¨rk-Shiley tilting disk valve. Mean aortic pressure was sequentially increased from 83 to 147 mmHg, keeping the pump rate essentially constant (69–73 strokes/min). The porcine valve produced the least amount of total backflow (backflow due to closure plus leakage backflow) (1.6 to 2.4 mL/stroke). Among the mechanical valves the Bjo¨rk-Shiley valve showed the least amount of total backflow (5.0 to 6.0 mL/stroke). At a mean aortic pressure of 100 mmHg and a low cardiac output of 2 L/min, the total backflow with the porcine valve was only 6 percent of forward flow; whereas it was 19 percent with the Lillehei-Kaster valve, 22 percent with the St. Jude valve and 18 percent with the Bjo¨rk-Shiley valve. Leakage backflow at a given level of mean aortic pressure was, as expected, directly related to the annular clearance area. It is concluded that the Hancock valve showed the least amount of backward flow, which would be particularly beneficial in low output states. In the presence of normal hemodynamics, the amount of backflow with the three mechanical valves appeared to be well below the level of backflow considered to be clinically significant.

A Comparison of a Moderate with Moderate-high Intensity Oral Anticoagulant Treatment in Patients with Mechanical Heart Valve Prostheses

1997 ◽  
Vol 77 (05) ◽  
pp. 0839-0844 ◽  
Author(s):  
Vittorio Pengo ◽  
Fabio Barbero ◽  
Alberto Banzato ◽  
Elisabetta Garelli ◽  
Franco Noventa ◽  
...  
Keyword(s):  
Heart Valve ◽  
High Intensity ◽  
Oral Anticoagulant ◽  
Oral Anticoagulants ◽  
Mechanical Heart Valve ◽  
Moderate Intensity ◽  
Minor Bleeding ◽  
Anticoagulant Treatment ◽  
Oral Anticoagulant Treatment ◽  
Valve Prostheses

SummaryBackground. The long-term administration of oral anticoagulants to patients with mechanical heart valve prostheses is generally accepted. However, the appropriate intensity of oral anticoagulant treatment in these patients is still controversial.Methods and Results. From March 1991 to March 1994, patients referred to the Padova Thrombosis Center who had undergone mechanical heart valve substitution at least 6 months earlier were randomly assigned to receive oral anticoagulants at moderate intensity (target INR = 3) or moderate-high intensity (target INR = 4). Principal end points were major bleeding, thromboembolism and vascular death. Minor bleeding was a secondary end-point.A total of 104 patients were assigned to the target 3 group and 101 to the target 4 group; they were followed for from 1.5 years to up 4.5 years (mean, 3 years). Principal end-points occurred in 13 patients in the target 3 group (4 per 100 patient-years) and in 20 patients in the target 4 group (6.9 per 100 patient-years). Major hemorrhagic events occurred in 15 patients, 4 in the target 3 group (1.2 per 100 patient-years) and 11 in the target 4 group (3.8 per 100 patient-years) (p = 0.019). The 12 recorded episodes of thromboembolism, 4 of which consisted of a visual deficit, were all transient ischemic attacks, 6 in the target 3 group (1.8 per 100 patient-years) and 6 in the target 4 group (2.1 per 100 patient- years). There were 3 vascular deaths in each group (0.9 and 1 per 100 patient-years for target 3 and target 4 groups, respectively). Minor bleeding episodes occurred 85 times (26 per 100 patient-years) in the target 3 group and 123 times (43 per 100 patient-years) in the target 4 group (p = 0.001).Conclusions. Mechanical heart valve patients on anticoagulant treatment who had been operated on at least 6 months earlier experienced fewer bleeding complications when maintained on a moderate intensity regimen (target INR = 3) than those on a moderate-high intensity regimen (target INR = 4). The number of thromboembolic events and vascular deaths did not differ between the two groups.

Pulmonary Homografts for Aortic Valve Replacement: Long-term Comparison with Aortic Grafts

2011 ◽  
Vol 14 (4) ◽  
pp. 237 ◽  
Author(s):  
Ferdinand Vogt ◽  
Anke Kowert ◽  
Andres Beiras-Fernandez ◽  
Martin Oberhoffer ◽  
Ingo Kaczmarek ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Replacement ◽  
Valve Replacement ◽  
Survival Rates ◽  
Long Term Results ◽  
Rank Test ◽  
Aortic Graft ◽  
Valve Prostheses ◽  
Retrospective Comparative Study

<p><b>Objective:</b> The use of homografts for aortic valve replacement (AVR) is an alternative to mechanical or biological valve prostheses, especially in younger patients. This retrospective comparative study evaluated our single-center long-term results, with a focus on the different origins of the homografts.</p><p><b>Methods:</b> Since 1992, 366 adult patients have undergone AVR with homografts at our center. We compared 320 homografts of aortic origin and 46 homografts of pulmonary origin. The grafts were implanted via either a subcoronary technique or the root replacement technique. We performed a multivariate analysis to identify independent factors that influence survival. Freedom from reintervention and survival rates were calculated as cumulative events according to the Kaplan-Meier method, and differences were tested with the log-rank test.</p><p><b>Results:</b> Overall mortality within 1 year was 6.5% (21/320) in the aortic graft group and 17.4% (8/46) in the pulmonary graft group. In the pulmonary graft group, 4 patients died from valve-related complications, 1 patient died after additional heterotopic heart transplantation, and 1 patient who entered with a primary higher risk died from a prosthesis infection. Two patients died from non-valve-related causes. During the long-term follow-up, the 15-year survival rate was 79.9% for patients in the aortic graft group and 68.7% for patients in the pulmonary graft group (<i>P</i> = .049). The rate of freedom from reoperation was 77.7% in the aortic graft group and 57.4% in the pulmonary graft group (<i>P</i> < .001). The reasons for homograft explantation were graft infections (aortic graft group, 5.0%; pulmonary graft group, 6.5%) and degeneration (aortic graft group, 7.5%; pulmonary graft group, 32.6%).</p><p><b>Conclusion:</b> Our study demonstrated superior rates of survival and freedom from reintervention after AVR with aortic homografts. Implantation with a pulmonary graft was associated with a higher risk of redo surgery, owing to earlier degenerative alterations.</p>

Pressure Recovery in Bileaflet Heart Valve Prostheses

Circulation ◽  
1995 ◽  
Vol 92 (12) ◽  
pp. 3464-3472 ◽  
Author(s):  
Pieter M. Vandervoort ◽  
Neil L. Greenberg ◽  
Min Pu ◽  
Kimerly A. Powell ◽  
Delos M. Cosgrove ◽  
...  
Keyword(s):  
Heart Valve ◽  
Pressure Recovery ◽  
Heart Valve Prostheses ◽  
Valve Prostheses
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