An alternative to left ventricular volume reduction.
BACKGROUND
Left ventricular (LV) remodeling leading to ventricular dilatation is ultimately a maladaptative process according to the law of Laplace. To counteract the wall stress increase, a new concept of reducing the LV cavity radius by changing the LV globular shape to a bilobular one through the insertion of transventricular splints has emerged. This procedure is tested in a model of congestive heart failure.


METHODS
A bovine model was used (n = 9). Following splint insertion through a sternotomy, boluses of 2 liters of crystalloid were injected. After every bolus, hemodynamic measurements were performed without and with the splints tightened to a 10% and 20% stress level reduction, respectively. Comparisons between the 3 measurements were performed with analysis of variance test (p < 0.05).


RESULTS
Splint tightening significantly reduced right and left heart pressures for central venous pressure (CVP) >10 mm Hg (CVP: 14.7 +/- 5.2, 12.1 +/- 5, 10.6 +/- 4.7 mm Hg, p < 0.001 for baseline, 10% and 20% stress level reduction, respectively; mean pulmonary artery pressure: 33.5 +/- 4.7, 31 +/- 4.4, 29.4 +/- 5.1 mm Hg, p < 0.001; pulmonary capillary wedge pressure: 20.5 +/- 2.8, 18.9 +/- 3.3, 17.5 +/- 3.1 mm Hg, p < 0.001). The same holds true for cardiac output (6.5 +/- 1.6, 6.7 +/- 1.4, 6.8 +/- 1.7 liter/minute, p < 0.001), whereas heart rate and mean arterial pressure were not affected. The systemic and pulmonary resistances did not vary significantly throughout the procedure. Importantly, none of the hemodynamic parameters worsened at any stage with the splints.


CONCLUSIONS
In this model, hemodynamic parameters are improved with the splints for higher values of CVP, supporting the concept of reshaping the remodeled LV. This technique has the potential to improve patients with congestive heart failure.
Mueller
Xavier M
XM
Department of Cardio-vascular Surgery, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland. Xavier.Mueller@chuv.hospvd.ch
Tevaearai
Hendrik
H
Boone
Yves
Y
Augstburger
Monique
M
von Segesser
Ludwig K
LK
D000818:Animals; D002417:Cattle; D004195:Disease Models, Animal; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006352:Heart Ventricles; D006439:Hemodynamics; D019736:Prostheses and Implants; D013165:Splints