Total anomalous pulmonary venous return (TAPVR) is a cyanotic congenital heart anomaly with an abnormal drainage anatomy of the entire pulmonary venous system. This contrasts with partial anomalous pulmonary venous return (PAPVR) where only part of the pulmonary veins are abnormal.
In TAPVR there is nothing draining into the left atrium. Therefore in order to complete the circuit there is almost always an associated shunting defect which is most frequently a patent foramen ovale (PFO)
Pathology
Embryological failure of pulmonary venous development resulting is persistent patency of primitive systemic veins.
Classification
Can be classified into 4 types depending on site of anomalous venous union1
* type I : supracardiac ( commonest > 50 % ) : drainage is to either left brachiocephalic, SVC or aygous vein
* type II : cardiac ( next commonest ~ 30% ) : drainage is to coronary sinus, right atrium
* type III : infracardiac : drainage usually below the diaphragm to ductus venosus, IVC, portal vein or hepatic veins
* type IV : mixed pattern
Radiographic features
Plain film
The supra cardiac variant can classically depict a "Snowman" type appearance on a frontal chest radiograph 2. The 1st two types give cardiomegaly.
CT / MRA
Direct visualisation of anomalous venous return.
Echocardiography / Ultrasound
Blind ended left atrium with no connecting veins.
Associations
* asplenia
* heterotaxy syndrome
* thoracic lymphangiectasia : infra cardiac
* pulmonary congestion : infra cardiac
Article Source : Dr Yuranga Weerakkody, Radiopaedia
References
- Demos TC, Posniak HV, Pierce KL et-al. Venous anomalies of the thorax. AJR Am J Roentgenol. 2004;182 (5): 1139-50. AJR Am J Roentgenol (full text) - Pubmed citation
- Ferguson EC, Krishnamurthy R, Oldham SA. Classic imaging signs of congenital cardiovascular abnormalities. Radiographics. 27 (5): 1323-34. doi:10.1148/rg.275065148 - Pubmed citation