Acute hemodynamic changes after experimental Fontan circulation in a swine model without the use of bypass

  • Dr Fotios Mitropoulos, Department of Pediatric and Congenital Heart Surgery, Onassis Cardiac Surgery Centre, Athens, Greece, Greece
  • Dr Meletios Kanakis, Center for Experimental Surgery Biomedical Research Foundation Academy of Athens, Athens, Greece, Greece
  • Dr Dimitrios Angouras, Department of Cardiac Surgery, Attikon Hospital, University of Athens, Greece
  • MSc Constantine Dimitriou, Center for Experimental Surgery Biomedical Research Foundation Academy of Athens, Athens, Greece, Greece
  • Vet Michael Katsimpoulas, Center for Experimental Surgery Biomedical Research Foundation Academy of Athens, Athens, Greece, Greece
  • Dr Chris Rokkas, Department of Cardiac Surgery, Attikon Hospital, University of Athens, Greece, Greece
  • Pr Panayiotis Karayannacos, Center for Experimental Surgery Biomedical Research Foundation Academy of Athens, Athens, Greece, Greece
  • Pr Constantine Anagnostopoulos, Department of Cardiac Surgery, Attikon Hospital, University of Athens

    • Objective: Our study uses a swine model of total cavopulmonary connection (TCPC) to test the hemodynamic performance before and after the establishment of (TCPC) without the use of cardiopulmonary bypass (CPB) or other means of temporary bypass.
    Methods: 8 anesthetized animals (mean weight 43kg, mean age 4.5months) underwent (TCPC). This was established by the use of an appropriate size Y-shaped conduit connecting and draining superior and inferior caval veins (end to end anastomosis) to the pulmonary trunk (end to side anastomosis). Decompression of the right ventricle was achieved with the use of a roller pump. Before and after the establishment of TCPC, hemodynamic parameters were recorded.
    Results: All animals needed volume loading during the performance of the end to end anastomosis between the graft and the great veins. One animal needed inotropic support.
    All animals demonstrated hemodynamic stability after the institution of the Fontan circulation. When the TCPC was established, a statistically significant decrease was observed in the mean arterial pressure (P<0.001), cardiac output (P<0.0001), mean pulmonary artery pressure (P<0.001) and heart rate (P<0.01). A statistically significant increase in the inferior vena caval pressure (P<0.01) and in the pulmonary vascular resistance (P<0.05) was also observed. Changes in left atrial pressure and in systemic vascular resistance were not statistically significant.
    Conclusions: The establishment of a beating heart Fontan circulation without the use of CPB or other means of temporary bypass is feasible and our results are in concordance with the pattern of the Fontan paradox.

    Parameter Baseline (mean value ± SE) Fontan (mean value ± SE) p-value
    Mean Aortic Pressure (mmHg) 44.35 ± 2.36 28.57 ± 1.53 <0.001
    Mean Inferior Vena Caval pressure (mmHg) 13.8 ± 1.77 25.85 ± 2.00 <0.01
    Mean Left Atrial pressure (mmHg) 6.37 ± 0.92 4.15 ± 0.53 Not Significant
    Mean Pulmonary Artery Pressure (mmHg) 18.38 ± 0.60 11.03 ± 1.10 <0.001
    Pulmonary Vascular Resistance (Wood's units) 3.49 ± 0.21 5.97 ± 0.73 <0.05
    Cardiac Output (lt/min) 3.48 ± 0.27 1.17 ± 0.14 <0.0001
    Systemic Vascular Resistance (Wood's units) 11.11 ± 0.86 15.86 ± 2.19 Not Significant
    Heart Rate (per min) 89.45 ± 4.05 70.70 ± 3.33 <0.01