- Anatomy
- In TAPVC (colloquially, ‘total veins’), all pulmonary veins drain to a confluence behind the left atrium which does not connect with the left atrium proper, but instead drains to a vertical vein that (most commonly) drains to the innominate vein –> SVC –> RA. The left atrium fills via an obligate ASD with right to left flow. Left heart structures often measure smaller than normal.
- Pathophysiology
- When pulmonary venous return is unobstructed (i.e. clear CXR, minimal respiratory distress), the supracardiac TAPVC has ASD physiology (i.e. net left to right ‘atrial level’ flow). A flow-related gradient of 3-8 mmHg in the vertical vein, innominate vein, or SVC is common and does not suggest clinical obstruction. Absent significant lung disease, saturations are usually in the 80s and symptoms may be minimal, though some patients develop heart failure symptoms at 2-3 months. Timing of repair may be symptom-guided, otherwise at several months of age. In the case of clinically obstructed supracardiac TAPVC, preoperative support with diuretics and respiratory support (including intubation) may be required. In extreme cases (e.g. severe hypoxemia), urgent surgical repair is necessary.
Repair of Supracardiac TAPVC
- Postoperative considerations
- Was there preoperative clinical pulmonary vein obstruction (i.e. was the patient ventilated or the CXR congested)?
- If so, extubation may require diuresis, several days of mechanical ventilation, and post-extubation respiratory support. Pulmonary vein obstruction also causes reactive pulmonary hypertension that can persist post-repair. Monitoring for and treating RV hypertension (e.g. iNO), preventing atelectasis, and providing inotropic support may be helpful, particularly if the ASD was closed without a fenestration.
- In the early postoperative period, bleeding may sometimes cause tamponade physiology (narrow pulse pressure, elevated LAP) as thrombus may accumulate and compress the LA; when extreme this may require re-exploration. Some patients may return with open sternum, particularly if bleeding or concern for pulmonary hypertension is significant.
- In some patients cross-clamp time may be prolonged; monitor for low cardiac output.
- Was there preoperative clinical pulmonary vein obstruction (i.e. was the patient ventilated or the CXR congested)?
References
Guocheng Shi, MD et al. Total Anomalous Pulmonary Venous Connection [PDF]
Nicola Viola, MD et al. Surgical Repair of Post-Repair Pulmonary Vein Stenosis Using “Sutureless” Techniques [PDF]
Primary sutureless repair for “simple” total anomalous pulmonary venous connection: midterm results in a single institution [PDF]