Does the size of pulmonary artery (PA) still affect the Fontan circulation after completion of the procedure?

  • Dr Tatsuya Ando, The Jikei University School of Medicine, Japan
  • Dr Ryota Saito, The Jikei University School of Medicine, Japan
  • Dr Takashi Urashima, The Jikei University School of Medicine, Japan
  • Dr Masako Fujiwara, The Jikei University School of Medicine, Japan
  • Prof Makoto Nakazawa, The Jikei University School of Medicine, Japan
  • Prof Hiroyuki Ida, The Jikei University School of Medicine, Japan
  • Prof Kiyozo Morita, The Jikei University School of Medicine, Japan

    • Objective
    The aim of this study is to evaluate cardiac function in Fontan circulation, and investigate the implications of postoperative PA size in Fontan circulation.
    Methods
    The subjects were 17 consecutive patients with Fontan circulation. Cardiac output (CO) was measured by the pulse contour cardiac output monitoring system. Dobutamine was infused to analyze cardiac functional reserve.
    Results
    The mean age of the subjects was 8 years (range 2-34). The mean age when the patients underwent the Fontan procedure was 3.0 years (1-19). The mean value of Nakata index (PAI) and lower lobe index (LLI) was 262 (121-403) and 193(75-283), respectively. Baseline value of pulmonary arterial pressure was 10.9mmHg (8-16), and cardiac index(CI) was 3.2 l/min/m2(2.2-4.7). Heart rate and CO were increased by dobutamine infusion. We divided the patients into two groups based on baseline CI(3.0 l/min/m2) and maximal CI(4.0). PAI was significantly higher in groups with the higher baseline CI and maximal CI (p=0.003 and p=0.03). LLI was not a significant factor regarding CI in this study.
    Conclusion
    Nakata index is speculated to correlate with the total amount of pulmonary blood flow. Thus it may represent cardiac output in Fontan circulation. Recently, some authors suggested small preoperative PA size did not matter in the completion of Fontan procedure. However, if PA size limits cardiac output in Fontan circulation, the PA size is still remaining important. The options such as additional PA flow, or PA enlargement before Fontan procedure might be helpful to the patients with small PA, regarding CO.