Significance of Additional Pulmonary Blood Flow between Stages 2 and 3 in Fontan Pathway

Objectives: The benefit of additional pulmonary blood flow (APBF) between stages 2 and 3 of Fontan pathway remains controversial. On one hand, APBF can result in higher oxygen saturation and improve the development of the pulmonary arteries, on the other can cause a volume overload for the single ventricle and worse the function of the ventricle and the atrioventricular (AV) valve.

Methods: A group of 180 consecutive patients (median age: 2.92 (1.83–16.83) years, median weight: 13.7 (9.7–74.57) kg) with multiple variants of single ventricle underwent Fontan operation with extracardiac conduit in a single institution. The patients were divided in two groups according to the presence of an alternative to the Glenn anastomosis source of pulmonary blood flow between stages 2 and 3 (Group 1—absence; Group 2—presence of APBF). The preoperative parameters and the postoperative course were retrospectively analyzed.

Result: There were four types of APBF in Group 2: native pulmonary artery 39 [59%], RV-PA shunt 23 [35%], BT shunt 2 [3%], and central shunt 2 [3%]. There was no difference in preoperative age (p = 0.358), weight (p = 0.509), and hemoglobin level (p = 0.509). Preoperative echocardiography showed no differences in ventricular function (good—105 [95%] vs. 65 [98.5%]; reduced—9 [5%] vs. 1 [1.5%]; p = 0.072) or AV valve function (p = 0.783). There was no difference in oxygen saturation at admission (p = 0.484), in preoperative blood gas analysis (p = 0.624), in the first 6 postoperative hours (p = 0.139), or at the discharge (p = 0.726). In the preoperative cardiac catheterization, there was no difference in size of the left pulmonary artery (9.5 (0–16.2) vs. 10.55 (4.88–21.7) mm; p = 0.128), but the right pulmonary artery was significantly larger (11.2 [6.5–19.6] vs. 12.8 (7.8–25.5) mm; p = 0.048). The length of intensive care unit stay (2 [1–23] vs. 2 [1–11] days; p = 0.358), hospital stay (16 [8–64] vs. 15 [10–36] days; p = 0.682) and pleura drainage loss (106.65 [12.29–1,811.34] vs. 91.3 [7.8–443.73] mL/kg; p = 0.171) were similar in both groups.

Conclusion: In our experience, an additional to Glenn anastomosis pulmonary blood flow does not result in higher oxygen saturation, both before and after Fontan completion, but seems to stimulate the right pulmonary growth. The additional volume load to the single ventricle does not influence the ventricular or AV valve function, as well as the postoperative course.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
19 February 2021