H. Tevaearai - Profile on Academia.edu (original) (raw)
Papers by H. Tevaearai
Monopontage coronarien minimal invasif: optimalisation des performances après la phase dite d'apprentissage
Minimally invasive cardiac surgery requires a learning period before the advantages of the method... more Minimally invasive cardiac surgery requires a learning period before the advantages of the method can be demonstrated. We report the progress of our results over 21 consecutive months. 27 patients were considered for minimally invasive coronary bypass via a small thoracotomy. We compare the results of four consecutive groups corresponding to an initial period (July-December 1997; n = 7; 66.8 +/- 8.9 years), an intermediate period (January-June 1998; n = 4; 48.1 +/- 11.2 years), an advanced period (July-December 1998; n = 7; 62.9 +/- 7.0 years) and a current period (January-March 1999; n = 7; 59.3 +/- 10.9 years). 2 patients were converted to sternotomy during the first year of experience. The operating time was reduced from 124 +/- 14 min and 118 +/- 20 min during the initial and intermediate periods to 99 +/- 18 and 98 +/- 18 min during the last two periods. The ICU stay was 2.6 +/- 1.1 days during the initial period and diminished respectively to 1.5 +/- 0.6, 1.7 +/- 0.8 and 1.6 +/- 0.5 days during the intermediate, advanced and current periods. The postoperative hospital stay was reduced from 9.0 +/- 1.4 days to 6.3 +/- 4.6, 5.2 +/- 1.7 and 5.9 +/- 1.5 days respectively. The benefits of minimally invasive coronary bypass were estimated by comparing the results of the last two periods with those of patients operated on through a sternotomy, on a beating heart (n = 12; 62.6 +/- 8.2) or under CPB (n = 81; 63.0 +/- 8.5). In these situations, operative time was 144 +/- 41 min and 180 +/- 35 min respectively. The ICU stay was 1.5 +/- 0.6 and 2.2 +/- 0.9 days, and the postoperative hospital stay was 7.5 +/- 2.8 and 8.6 +/- 3.0 days. We conclude that a learning period is necessary before the real benefits of the minimally invasive approach to coronary disease can be demonstrated. This method will soon replace traditional sternotomy in certain indications
Hepato-Biliary Disease and Heart Transplantation
Hemoglobine susbsitute and cardiopulonary Bypass
Atrial, Ventricular, or Both Cannulation Sites to Optimize Left Ventricular Assistance?
ASAIO Journal, 2001
The efficiency of left ventricular assist devices (LVADs) depends on the capacity of the inflow c... more The efficiency of left ventricular assist devices (LVADs) depends on the capacity of the inflow cannula to drain blood into the pump. Left atrial (LA) and left ventricular (LV) sites were compared in an animal model mimicking different hemodynamic conditions. Three calves (56.3+/-5.0 kg) were equipped with a Thoratec LVAD. A regular cardiopulmonary bypass (CPB) circuit was used as a right ventricular assist device (RVAD) (jugular vein/pulmonary artery), and preload conditions were adjusted by storage (or perfusion) of blood into (or from) the venous reservoir. LA and LV drainage, tested separately or simultaneously, was measured by its effect on the LVAD's performance. The LVAD was used alone on a beating heart or together with the RVAD (biVAD) on a beating and on a fibrillating heart. Increasing the central venous pressure (CVP) highlighted the differences between the LA and LV cannulation sites when the LVAD was tested either alone or together with the RVAD (biVAD) on a beating heart. Drainage through the LA or the LV was similar when CVP was set at 8 mm Hg, and increasing CVP to 14 mm Hg allowed for better drainage through the LV cannula. In contrast, after induction of fibrillation to mimic extreme heart failure, the drainage was better through the LA cannula. Using both LA and LV cannulae simultaneously did not improve the LVAD output in any of the conditions tested. LV cannulation provides better blood drainage when used on a normal beating heart and, therefore, allows for increased LVAD performance. However, in severe heart failure, blood drainage through the LV cannula decreases and the LA cannulation site is superior.
Pontages coronariens à coeur battant chez les patients avec une pathologie chirurgicale extra-cardiaque. [424]
Performance of a new implantable and auto heparinized cardiac assist device
A new device for less invasive left ventricular volume reduction. 37th annual meeting. Moral Convention Centre, New Orleans
Chirurgie cardiovasculaire expérimentale. Progrès dans le domaine des interventions à coeur battant
Catheter Jomed : nouvelle pompe d'assistance circulatoire
Kardiovasculäre Medizin, 1999
European Journal of Cancer, 1992
Acknowledgements-We would like to thank Grace Chojnowski for flow cytometric analysis of DNA cont... more Acknowledgements-We would like to thank Grace Chojnowski for flow cytometric analysis of DNA content and Irene Perkic for help in preparation of the manuscript. S.D. was supported by the Myra DeGroot Foundation.
Papierposter oder PC-Poster
medicalforum.ch
... Matthias K. Widmer, Daniela Michallik, Hendrik Tevaearai, Juerg Schmidli, Thierry Carrel Klin... more ... Matthias K. Widmer, Daniela Michallik, Hendrik Tevaearai, Juerg Schmidli, Thierry Carrel Klinik für Herz-und Gefässchirurgie, Universitätsspital Bern ... Präsentieren Sie den Text auf eine logische Art und Weise («roter Faden») zum Beispiel mit Untertiteln (Einleitung, Methoden ...
Is Endomyocardial Blood Flow Necessary for Growth Factor Induced Angiogenesis in Transmyocardial Laser Revascularization?
ASAIO Journal, 2000
The Journal of extra-corporeal technology, 2003
Vacuum-assist venous drainage (VAVD) can increase venous blood return during cardiopulmonary bypa... more Vacuum-assist venous drainage (VAVD) can increase venous blood return during cardiopulmonary bypass (CPB) procedures. However, the negative pressure created in the closed cardiotomy reservoir can be transmitted to the oxygenator if a nonocclusive or centrifugal arterial pump is used, resulting in bubble transgression (BT) from the gas to blood compartment of the oxygenator. We analyzed the vacuum pressure required to produce BT using an in vitro circuit including successively a closed reservoir, a pump (centrifugal or roller), and an oxygenator. A constant hydrostatic pressure was maintained onto the oxygenator. Vacuum was applied on the cardiotomy reservoir, progressively increasing negative pressure from 0 to -80 mmHg and monitoring BT with a bubble detector. Six different oxygenators were compared. A partially occlusive roller pump and a centrifugal pump were compared to a control, which was without any pump. A mean negative pressure of -53 +/- 7 mmHg was necessary to produce BT ...
Hemolysis and blood profile during perfusion : species difference
Comparative performance between mono and coaxial venous cannulae used in minimally invasive open heart surgery
Lésions endothéliales des ballons de contre-pulsions intra-aortique
Effect of cyclosporine dose reduction on renal function and blood pressure in the long term follow-up after heart transplantation
Amélioration de la perfusion systémique et coronarienne lors de massage cardiaque à l'aide d'un gilet pneumatique automatique
A portable heparin-coated ECMO circuit for right ventricular failure after tetralogy of Fallot repair
Monopontage coronarien minimal invasif: optimalisation des performances après la phase dite d'apprentissage
Minimally invasive cardiac surgery requires a learning period before the advantages of the method... more Minimally invasive cardiac surgery requires a learning period before the advantages of the method can be demonstrated. We report the progress of our results over 21 consecutive months. 27 patients were considered for minimally invasive coronary bypass via a small thoracotomy. We compare the results of four consecutive groups corresponding to an initial period (July-December 1997; n = 7; 66.8 +/- 8.9 years), an intermediate period (January-June 1998; n = 4; 48.1 +/- 11.2 years), an advanced period (July-December 1998; n = 7; 62.9 +/- 7.0 years) and a current period (January-March 1999; n = 7; 59.3 +/- 10.9 years). 2 patients were converted to sternotomy during the first year of experience. The operating time was reduced from 124 +/- 14 min and 118 +/- 20 min during the initial and intermediate periods to 99 +/- 18 and 98 +/- 18 min during the last two periods. The ICU stay was 2.6 +/- 1.1 days during the initial period and diminished respectively to 1.5 +/- 0.6, 1.7 +/- 0.8 and 1.6 +/- 0.5 days during the intermediate, advanced and current periods. The postoperative hospital stay was reduced from 9.0 +/- 1.4 days to 6.3 +/- 4.6, 5.2 +/- 1.7 and 5.9 +/- 1.5 days respectively. The benefits of minimally invasive coronary bypass were estimated by comparing the results of the last two periods with those of patients operated on through a sternotomy, on a beating heart (n = 12; 62.6 +/- 8.2) or under CPB (n = 81; 63.0 +/- 8.5). In these situations, operative time was 144 +/- 41 min and 180 +/- 35 min respectively. The ICU stay was 1.5 +/- 0.6 and 2.2 +/- 0.9 days, and the postoperative hospital stay was 7.5 +/- 2.8 and 8.6 +/- 3.0 days. We conclude that a learning period is necessary before the real benefits of the minimally invasive approach to coronary disease can be demonstrated. This method will soon replace traditional sternotomy in certain indications
Hepato-Biliary Disease and Heart Transplantation
Hemoglobine susbsitute and cardiopulonary Bypass
Atrial, Ventricular, or Both Cannulation Sites to Optimize Left Ventricular Assistance?
ASAIO Journal, 2001
The efficiency of left ventricular assist devices (LVADs) depends on the capacity of the inflow c... more The efficiency of left ventricular assist devices (LVADs) depends on the capacity of the inflow cannula to drain blood into the pump. Left atrial (LA) and left ventricular (LV) sites were compared in an animal model mimicking different hemodynamic conditions. Three calves (56.3+/-5.0 kg) were equipped with a Thoratec LVAD. A regular cardiopulmonary bypass (CPB) circuit was used as a right ventricular assist device (RVAD) (jugular vein/pulmonary artery), and preload conditions were adjusted by storage (or perfusion) of blood into (or from) the venous reservoir. LA and LV drainage, tested separately or simultaneously, was measured by its effect on the LVAD's performance. The LVAD was used alone on a beating heart or together with the RVAD (biVAD) on a beating and on a fibrillating heart. Increasing the central venous pressure (CVP) highlighted the differences between the LA and LV cannulation sites when the LVAD was tested either alone or together with the RVAD (biVAD) on a beating heart. Drainage through the LA or the LV was similar when CVP was set at 8 mm Hg, and increasing CVP to 14 mm Hg allowed for better drainage through the LV cannula. In contrast, after induction of fibrillation to mimic extreme heart failure, the drainage was better through the LA cannula. Using both LA and LV cannulae simultaneously did not improve the LVAD output in any of the conditions tested. LV cannulation provides better blood drainage when used on a normal beating heart and, therefore, allows for increased LVAD performance. However, in severe heart failure, blood drainage through the LV cannula decreases and the LA cannulation site is superior.
Pontages coronariens à coeur battant chez les patients avec une pathologie chirurgicale extra-cardiaque. [424]
Performance of a new implantable and auto heparinized cardiac assist device
A new device for less invasive left ventricular volume reduction. 37th annual meeting. Moral Convention Centre, New Orleans
Chirurgie cardiovasculaire expérimentale. Progrès dans le domaine des interventions à coeur battant
Catheter Jomed : nouvelle pompe d'assistance circulatoire
Kardiovasculäre Medizin, 1999
European Journal of Cancer, 1992
Acknowledgements-We would like to thank Grace Chojnowski for flow cytometric analysis of DNA cont... more Acknowledgements-We would like to thank Grace Chojnowski for flow cytometric analysis of DNA content and Irene Perkic for help in preparation of the manuscript. S.D. was supported by the Myra DeGroot Foundation.
Papierposter oder PC-Poster
medicalforum.ch
... Matthias K. Widmer, Daniela Michallik, Hendrik Tevaearai, Juerg Schmidli, Thierry Carrel Klin... more ... Matthias K. Widmer, Daniela Michallik, Hendrik Tevaearai, Juerg Schmidli, Thierry Carrel Klinik für Herz-und Gefässchirurgie, Universitätsspital Bern ... Präsentieren Sie den Text auf eine logische Art und Weise («roter Faden») zum Beispiel mit Untertiteln (Einleitung, Methoden ...
Is Endomyocardial Blood Flow Necessary for Growth Factor Induced Angiogenesis in Transmyocardial Laser Revascularization?
ASAIO Journal, 2000
The Journal of extra-corporeal technology, 2003
Vacuum-assist venous drainage (VAVD) can increase venous blood return during cardiopulmonary bypa... more Vacuum-assist venous drainage (VAVD) can increase venous blood return during cardiopulmonary bypass (CPB) procedures. However, the negative pressure created in the closed cardiotomy reservoir can be transmitted to the oxygenator if a nonocclusive or centrifugal arterial pump is used, resulting in bubble transgression (BT) from the gas to blood compartment of the oxygenator. We analyzed the vacuum pressure required to produce BT using an in vitro circuit including successively a closed reservoir, a pump (centrifugal or roller), and an oxygenator. A constant hydrostatic pressure was maintained onto the oxygenator. Vacuum was applied on the cardiotomy reservoir, progressively increasing negative pressure from 0 to -80 mmHg and monitoring BT with a bubble detector. Six different oxygenators were compared. A partially occlusive roller pump and a centrifugal pump were compared to a control, which was without any pump. A mean negative pressure of -53 +/- 7 mmHg was necessary to produce BT ...
Hemolysis and blood profile during perfusion : species difference
Comparative performance between mono and coaxial venous cannulae used in minimally invasive open heart surgery
Lésions endothéliales des ballons de contre-pulsions intra-aortique
Effect of cyclosporine dose reduction on renal function and blood pressure in the long term follow-up after heart transplantation
Amélioration de la perfusion systémique et coronarienne lors de massage cardiaque à l'aide d'un gilet pneumatique automatique
A portable heparin-coated ECMO circuit for right ventricular failure after tetralogy of Fallot repair