Direct Reverse Flow From the Left to Right Pulmonary Arteries in Tetralogy of Fallot With Absent Pulmonary Valve, Evaluated by 4D Flow Magnetic Resonance Imaging

In tetralogy of Fallot (TOF) with absent pulmonary valve (APV), severe pulmonary regurgitation significantly enlarges the peripheral pulmonary artery (PA), leading to airway and pulmonary vein compression, and a poor prognosis.¹

4D flow magnetic resonance imaging (MRI) was performed before and after pulmonary valve replacement to evaluate pulmonary regurgitation and turbulent flow in the dilated left PA of a 10-year-old boy (Figure A,B). The reversed blood flow through the pulmonary valve significantly decreased after surgery, but the laterality of pulmonary blood flow remained unchanged (Figure C,D). Interestingly, direct-reversing flow was observed from the dilated left PA to the right PA (Supplementary Movie, Figure F), which can cause an imbalance between the left and right pulmonary blood flows.

Figure.

4D flow magnetic resonance imaging (MRI) images of the pulmonary artery before and after surgery. (A,B) Streamline. (C,D) Blood flow rate. (E,F) Pathline. Note: In the preoperative images (A,C,E), the bifurcation of the right pulmonary artery is not depicted on the MRI due to an implanted stent. Similarly, in the postoperative images (B,D,F), a portion of the bioprosthetic pulmonary valve is not depicted.

This is the first report of 4D flow MRI showing that a dilated PA in TOF with APV may act as a reservoir and contribute to direct-reversing flow between the right and left PAs even after pulmonary valve replacement.

Supplementary Files

Supplementary Movie. Direct-reversing flow from the dilated left pulmonary artery to the right pulmonary artery.

Please find supplementary file(s);

http://dx.doi.org/10.1253/circj.CJ-21-0199

Reference

• 1.   Kirshbom PM, Kogon BE. Tetralogy of Fallot with absent pulmonary valve syndrome. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2004; 7: 65–71.