A new classification for right top pulmonary vein.

BACKGROUND

The right top pulmonary vein (PV) has been defined as an anomalous branch of the right superior PV draining into the left atrium (LA); however, various PV anomalies and terminologies have been reported. To clarify the concept of the right top PV, we reviewed the literature and our cases.

METHODS

We reviewed the literature on the right top PV, right PV passing behind the intermediate bronchus (BIB), and related PV anomalies. We also reviewed our anomalous PV cases, which were analyzed using 3-dimensional computed tomography (3D-CT).

RESULTS

Authors of the previous reports were radiologists, surgeons, and cardiologists. The terminologies used in the literature included PV branch crossing BIB, right upper lobe vein posterior to the bronchus intermedius, and right isolated superior posterior branch. The frequency of the anomaly in the literature ranged from 0.3% to 9.3%. Anomalous PVs originated from either the right upper lobe or the lower lobe. We found the following among 303 patients with chest disorders at our hospital: 10 (3.3%) of these PV anomalies were observed-4 drained directly into the LA and the other 4 drained into the right superior PV. Among 9 patients who were analyzed and had complete interlobar fissures between the upper and lower lobes, 4 patients had drainage from both the right upper and the lower lobes. Eight PVs passed BIB, 1 passed behind the main bronchus (BMB), and the other passed both BIB and BMB.

CONCLUSIONS

We propose that the term right top PV should be used in a broad sense, being defined as "an anomalous branch of PV draining directly into the left atrium (LA)," and that it be classified into 6 types.