Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
MEDTRONIC-HALL VERSUS ST. JUDE MEDICAL MECHANICAL AORTIC-VALVE - DOWNSTREAM TURBULENCES WITH RESPECT TO ROTATION IN PIGS
Autore:
KLEINE P; PERTHEL M; NYGAARD H; HANSEN SB; PAULSEN PK; RIIS C; LAAS J;
Indirizzi:
HERZ KREISLAUF KLIN BEVENSEN,DEPT THORAC & CARDIOVASC SURG,ROMSTEDTERSTR 25 D-29549 BAD BEVENSON GERMANY HERZ KREISLAUF KLIN BEVENSEN,DEPT THORAC & CARDIOVASC SURG D-29549 BAD BEVENSON GERMANY AARHUS UNIV HOSP,SKEJBY SYGEHUS,DEPT CARDIOTHORAC & VASC SURG DK-8000AARHUS DENMARK
Titolo Testata:
Journal of heart valve disease
fascicolo: 5, volume: 7, anno: 1998,
pagine: 548 - 555
SICI:
0966-8519(1998)7:5<548:MVSJMM>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
STRESS-DISTRIBUTION DOWNSTREAM; LEFT-VENTRICULAR HYPERTROPHY; PULSATILE FLOW; VELOCITY; HUMANS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
24
Recensione:
Indirizzi per estratti:
Citazione:
P. Kleine et al., "MEDTRONIC-HALL VERSUS ST. JUDE MEDICAL MECHANICAL AORTIC-VALVE - DOWNSTREAM TURBULENCES WITH RESPECT TO ROTATION IN PIGS", Journal of heart valve disease, 7(5), 1998, pp. 548-555

Abstract

Background and aims of the study: Turbulences downstream of mechanical aortic valves are known to contribute to most valve-related complications such as thrombosis, embolization or damage to blood components. In vitro studies have demonstrated the impact of the orientation of prostheses on transvalvular energy loss. This study evaluates the influence of valve orientation on turbulences in the supravalvular aorta in pigs. Methods: A rotation device which could carry a Medtronic Hall(MH) or St. Jude Medical (SJM) aortic valve prosthesis (23 mm) was constructed and implanted into four healthy pigs. Turbulence measurements using pulsed Doppler ultrasonography were carried out 3 cm downstream ofthe valve, while the prostheses were rotated in 45 degrees steps. Reynold's normal stress values (RNS) were calculated as key markers for turbulent stresses. Results: Turbulences downstream of MH and SJM valves demonstrated a significant change with rotation. The MH valve showedminimum RNSmean values with orientation of the large orifice to the right posterior aortic wall, which is the area of highest velocities during ejection. With this orientation, aortic flow almost complied withphysiologic conditions. Increase of turbulence was observed with any other position. The SJM valve revealed significant turbulent flow at any orientation. Minimum RNSmean values were also measured with one orifice facing the right posterior wall of the aorta. Conclusion: With optimum orientation (major orifice facing the right posterior aortic wall) the MH valve matches the aortic flow pattern to near-normal physiology. The flow patterns of the SJM valve are less susceptible to rotation, but cannot attain the optimum RNS values of the MII prosthesis.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/09/20 alle ore 23:51:15