Cardiovascular

Microcirculatory Alterations and Endothelial Glycocalyx in Fontan Circulation: Association With Central Venous Pressure.

Shiraishi M, Izumi G, Saito H • Microcirculation (New York, N.Y. : 1994) • 2026

TL;DR

Fontan circulation is associated with an increased PBR, suggesting alterations of the endothelial glycocalyx, and the association between PBR and CVP suggests that chronic venous hypertension may be associated with systemic microcirculatory alterations in Fontan circulation.

Key Findings

Results

Patients with Fontan circulation had significantly higher perfused boundary region (PBR), an inverse indicator of glycocalyx dimensions, than patients with biventricular circulation.

PBR was 2.07 ± 0.15 μm in the Fontan group vs. 1.72 ± 0.17 μm in the biventricular group (p < 0.0001).
PBR was measured noninvasively using GlycoCheck.
A higher PBR is interpreted as suggesting alterations of the endothelial glycocalyx.

Results

Central venous pressure (CVP) was significantly higher in Fontan patients than in biventricular patients.

CVP was 13.0 ± 2.2 mmHg in the Fontan group vs. 7.1 ± 2.8 mmHg in the biventricular group (p < 0.0001).
This is consistent with the chronically elevated CVP characteristic of Fontan circulation.

Results

PBR was positively correlated with CVP across the cohort.

The correlation was r = 0.58, p < 0.0001.
The authors interpret this as suggesting chronic venous hypertension may be associated with systemic microcirculatory alterations in Fontan circulation.

Methods

The study cohort comprised 44 patients with congenital heart disease undergoing postoperative endothelial glycocalyx evaluation, 14 with Fontan circulation and 30 with biventricular circulation.

The Fontan group included three patients with bidirectional Glenn circulation.
PBR was compared between the Fontan and biventricular groups and its relationship with CVP was evaluated.

What This Means

This study looked at the tiny blood vessels of children and adults with congenital heart disease. People with a Fontan circulation, a surgical arrangement for certain single-ventricle heart defects, have chronically high pressure in their veins and reduced heart output. The researchers asked whether this affects the glycocalyx, a thin protective layer lining the inside of blood vessels. They compared 14 patients with Fontan circulation (three had a related Glenn circulation) with 30 patients with a two-ventricle heart. Using a noninvasive device, they measured the perfused boundary region (PBR), where a higher value suggests a thinner or more damaged glycocalyx. PBR was higher in the Fontan group (2.07 vs. 1.72 μm), and central venous pressure was also higher (13.0 vs. 7.1 mmHg). Across all patients, higher venous pressure went along with higher PBR (r = 0.58). This research suggests that Fontan circulation is linked to changes in the blood vessel lining, and that long-term high venous pressure may be related to these changes. The study was small and shows association only, so it cannot prove that high pressure causes the glycocalyx changes or show what the changes mean for patients' health.

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Citation

Shiraishi M, Izumi G, Saito H. (2026). Microcirculatory Alterations and Endothelial Glycocalyx in Fontan Circulation: Association With Central Venous Pressure.. Microcirculation (New York, N.Y. : 1994). https://doi.org/10.1111/micc.70092

Key Findings

What This Means

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