Unusual systemic venous Collateral channels to left atrium causing desaturation after Fontan operation closed percutaneously
A 7-year-old girl child, had tetralogy of Fallot with hypoplastic right ventricle and adequate branch pulmonary arteries (tricuspid valve measured 8.5 mm, “Z” score -4.2 at the time of Fontan completion). She had undergone modified right Blalock–Taussig (BT) shunt in infancy followed by bidirectional Glenn shunt and ligation of pulmonary artery and takedown of BT shunt at 16 months of age. She was regularly followed up and underwent extracardiac Fontan at the age of 5½ years.\nPre-Fontan cardiac catheterization had revealed normal left ventricular (LV) filling pressure, mean pulmonary artery pressure, and pulmonary vascular resistance index.\nShe had a smooth postoperative course and was discharged after 9 days of surgery. Her oxygen saturation at the time of discharge was 95% in room air. A gradual return of cyanosis, exertional dyspnea, and easy fatigability was noted by the parents for the past 6 months. Her saturation was 85% at rest and 78% after (10 min) walking.\nCross-sectional echocardiography revealed normally functioning Fontan circuit. The ventricular function was normal, and there was no atrio-ventricular valve incompetence and no pericardial or pleural effusions. One small venous channel was seen arising from the brachiocephalic vein.\nPatient underwent cardiac catheterization; intracardiac pressures and Fontan pressures were normal. There was no fenestration. Innominate vein angiogram revealed a small venous channel descending on the left side. On selective injection, the venous channel was found to be communicating with the left atrium (LA). This channel was occluded using 0.038-inch, 5 mm × 5 cm Cook coil.\nInferior vena cava (IVC) angiogram revealed a large tortuous venous channel arising at T8-T9 level and draining into the LA [Figure and ]. Selective venous channel injection was also done which showed maximum diameter of venous channel 12 mm and the opening into LA measured 9.5 mm. An additional small vein was seen connecting the larger venous channel to the LA separately.\nLarger venous channel was test occluded using a 15 mm × 4 mm Tyshak balloon []. During occlusion, no hemodynamic instability was noted. There was no significant rise in systemic venous/Fontan pressure. The Fontan pressures before and after balloon occlusion were 12 mmHg and 13 mmHg, respectively. Systemic arterial saturation improved to 94% on balloon occlusion.\nThe smaller venous channel was first occluded using a 0.35-inch 5 mm × 5 cm Cook coil, whereas an 18-mm Amplatzer vascular plug was deployed in the larger channel []. Post-deployment IVC angiogram revealed complete occlusion of both the venous channels. Patient was discharged after 48 h of observation and has remained well at 6 months follow-up without any evidence of desaturation.