Utility of Balloon Occlusion Testing in Determining Fontan Suitability Among Patients with Elevated Pulmonary Artery Pressure and Additional Antegrade Pulmonary Blood Flow

In individuals with a single ventricle undergoing evaluation before Fontan surgery, the presence of excessive pulmonary blood flow can contribute to increased pulmonary artery pressure, notably in those who had a Glenn procedure with antegrade pulmonary flow. 28 patients who had previously undergone Glenn anastomosis with antegrade pulmonary blood flow (APBF) and with elevated mean pulmonary artery (mPAP) pressure > 15 mmHg in diagnostic catheter angiography were included in the study. After addressing other anatomical factors that could affect pulmonary artery pressure, APBF was occluded with semi-compliant, Wedge or sizing balloons to measure pulmonary artery pressure accurately. 23 patients (82% of the cohort) advanced to Fontan completion. In this group, median mPAP dropped from 20.5 (IQR 19–22) mmHg to 13 (IQR 12–14) mmHg post-test (p < 0.001). Median PVR post-test was 1.8 (IQR 1.5–2.1) WU m². SpO2 levels decreased from a median of 88% (IQR 86%–93%) pre-test to 80% (IQR 75%–84%) post-test (p < 0.001). In five patients, elevated mPAP post-test occlusion on diagnostic catheter angiography led to non-completion of Fontan circulation. In this group, median pre- and post-test mPAP were 23 mmHg (IQR 21.5–23.5) and 19 mmHg (IQR 18.5–20), respectively (p = 0.038). Median post-test PVR was 3.8 (IQR 3.6–4.5) WU m². SpO2 levels decreased from a median of 79% (IQR 76%–81%) pre-test to 77% (IQR 73.5%-80%) post-test (p = 0.039). Our study presents a specialized approach for patients initially deemed unsuitable for Fontan due to elevated pulmonary artery pressures. We were able to successfully complete the Fontan procedure in the majority of these high-risk cases after temporary balloon occlusion test.