Systemic-to-Pulmonary Collateral Flow, as Measured by Cardiac Magnetic Resonance Imaging, Is Associated With Acute Post-Fontan Clinical Outcomes

Abstract

Background Systemic-pulmonary collateral (SPC) flow occurs commonly in single ventricle patients after superior cavo-pulmonary connection, with unclear clinical significance. We sought to evaluate the association between SPC flow and acute post-Fontan clinical outcomes using a novel method of quantifying SPC flow by cardiac magnetic resonance (CMR). Methods and Results All patients who had SPC flow quantified by CMR prior to Fontan were retrospectively reviewed to assess for acute clinical outcomes after Fontan completion. Forty-four subjects were included who had Fontan completion between May, 2008 and September, 2010. SPC flow prior to Fontan measured 1.5 ± 0.9 L/min/m2, accounting for 31 ± 11% of total aortic flow and 44 ± 15% of total pulmonary venous flow. There was a significant linear association between natural log-transformed duration of hospitalization and SPC flow as a proportion of total aortic (rho=0.31, p=0.04) and total pulmonary venous flow (rho=0.29, p=0.05). After adjustment for Fontan type and presence of a fenestration, absolute SPC flow was significantly associated with hospital duration ≥ 7 days (OR=9.2, p=0.02) and chest tube duration ≥ 10 days (OR=22.7, p=0.009). Similar associations exist for SPC flow as a percentage of total aortic (OR=1.09, p=0.048 for hospitalization ≥ 7 days; OR=1.24, p=0.007 for chest tube duration ≥ 10 days) and total pulmonary venous flow (OR=1.07, p=0.048 for hospitalization ≥ 7 days; OR=1.18, p=0.006 for chest tube duration ≥ 10 days). Conclusions Increasing SPC flow before Fontan, as measured by CMR, is associated with increased duration of hospitalization and chest tube following Fontan completion.

Significance of systemic to pulmonary artery collaterals in single ventricle physiology: new insights from CMR imaging

“…These results are similar to those of Glatz et al 11 who also measured SPC flow by CMR prior to a Fontan operation and demonstrated that, after adjustment for Fontan type and fenestration, higher SPC flow was associated with dichotomous outcome variables including hospital duration ≥7 days (OR 9.2) and pleural drainage duration ≥10 days (OR 22.7). Linear relationships with outcome variables were either absent or less robust.…”

Energetic Implications of Vessel Growth and Flow Changes Over Time in Fontan Patients

“…Also, although we used advanced imaging techniques, there are some inherent limitations in spatial resolution that could affect the measurements. We did not take aortopulmonary collateral flow into account, which has been demonstrated in recent reports to be substantial and clinically relevant in some cases [36][37][38], and which could potentially have a measurable effect on TCPC energetics. All computational simulations were carried out with time-averaged flow rates and rigid vessel walls, and even though these methods provide a good approximation to the in vivo case [20,39], they may not be physiologically precise.…”

Aortopulmonary Collateral Flow is Related to Pulmonary Artery Size and Affects Ventricular Dimensions in Patients After the Fontan Procedure

“…Highlighting the clinical significance of APC flow, three studies recently demonstrated that increased collateral flow before the Fontan operation was associated with longer duration of pleural drainage and prolonged recovery in the postoperative period [6][7][8]. However, the mentioned studies primarily focused on technical aspects of quantifying APC flow [2][3][4] or were assessed in patients after the Glenn-procedure [6][7][8].…”