Background: Morbidity and mortality associated with single-ventricle physiology decrease substantially once a systemic venous, rather than systemic arterial, source of pulmonary blood flow is established. Cavopulmonary assist has potential to eliminate critical dependence on the problematic systemic-to-pulmonary shunt as a source of pulmonary blood flow in neonates. We have previously demonstrated feasibility of neonatal cavopulmonary assist under steady-flow conditions. We hypothesized that pulsatile pulmonary perfusion would further improve pulmonary hemodynamics.
Methods: Lambs (weight 7.2 +/- 1.1 kg, age 7.9 +/- 1.5 days) underwent total cavopulmonary diversion using bicaval venous-to-main pulmonary artery cannulation. A miniature centrifugal pump was used to augment cavopulmonary flow. Pulsatility was created with an intermittently compressed compliance chamber in the circuit. Hemodynamic and gas exchange data were measured for 8 hours. Pulsatile (n = 6), steady-flow (n = 13), and control (n = 6) groups were compared using two-way analysis of variance with repeated measures.
Results: All animals remained physiologically stable with normal gas exchange function. Mean pulmonary arterial pressure was elevated in pulsatile and steady-flow groups compared with the control group and within-group baseline values. Pulmonary vascular resistance was elevated initially in both assist groups but decreased significantly over the last 4 hours of the study and normalized after hour 4 in the pulsatile perfusion group. Pulmonary vascular resistance also normalized to control in the steady-flow group after hour 7.
Conclusions: Both steady-flow and pulsatile pulmonary perfusion demonstrated normalization of pulmonary vascular resistance to control in a neonatal model of univentricular Fontan circulation. These results suggest that there is no benefit to pulsatile flow in this model.
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http://dx.doi.org/10.1016/j.athoracsur.2005.07.003 | DOI Listing |
Artif Organs
January 2025
Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Background: Predicting hemolysis numerically based on the power-law model using idealized coefficients obtained from simplified devices yields a large variability in hemolysis index predictions. A computational fluid dynamics (CFD)-based Kriging surrogate modeling approach, developed by Craven et al. at the US Food & Drug Administration (FDA), was applied to a Fontan cavopulmonary assist device (CPAD) to generate device-specific hemolysis power-law coefficients.
View Article and Find Full Text PDFJTCVS Open
October 2024
Mechanical Solutions Inc, Whippany, NJ.
Objective: After Fontan palliation, patients with single-ventricle physiology are committed to chronic circulatory inefficiency for the duration of their lives. This is due in large part to the lack of a subpulmonary ventricle. A low-pressure rise cavopulmonary assist device can address the subpulmonary deficit and offset the Fontan paradox.
View Article and Find Full Text PDFCardiol Young
October 2024
Department of Congenital and Pediatric Heart Surgery, Technische Universität München, German Heart Center Munich, Munich, Germany.
Int J Artif Organs
October 2024
Department of Engineering, Durham University, Durham, UK.
Background: Fontan procedure, the standard surgical palliation to treat children with single ventricular defects, causes systemic complications over years due to lack of pumping at cavopulmonary junction. A device developed specifically for cavopulmonary support is thus considered, while current commercial ventricular assist devices (VAD) induce high shear rates to blood, and have issues with paediatric suitability.
Aim: To demonstrate the feasibility of a small, valveless, non-invasive to blood and pulsatile rotary pump, which integrates impedance and peristaltic effects.
J Soc Cardiovasc Angiogr Interv
April 2024
Cardiac Surgery Unit, Heart Transplant and MCS Program, Cardio-thoracic-vascular and Public Health Department, Padova University Hospital, Padova, Italy.
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