Partial Anomalous Pulmonary Venous Connection Encountered During Lung Resection for Non-small Cell Lung Cancer

Kyle Kalkwarf, MD; Richard Betzold, MD; Zachary Young, MD; Matthew Steliga, MD

INTRODUCTION: Partial anomalous pulmonary venous connection (PAPVC) is a rare congenital anomaly that often develops in combination with cardiac malformations such as atrial septal defect. It most often occurs as an anomaly of the right superior pulmonary vein draining into the superior vena cava (SVC) rather than the left atrium.1,2

CASE PRESENTATION: A 71 year-old woman with a remote ten pack-year-history of smoking presented with an incidentally found right upper-lobe nodule. Positron emission tomography-computed tomography (PET-CT) showed a 3 centimeter (cm) mass in the posteromedial right upper lobe with increased uptake on PET. Transesophageal biopsy was read as adenocarcinoma. Bronchoscopy revealed normal tracheobronchial anatomy and the pleural cavity was explored thoracoscopically. The mass was identified in the right upper lobe and no other nodules were detected. As the pleura was opened and the right superior pulmonary vein was dissected circumferentially, it became evident that this vein’s wall was thinner than the typical pulmonary vein and it was draining to the SVC anterior to the azygos vein [figure 1]. Intraoperative review of the CT confirmed PAPVC and the initial incision was extended to a muscle-sparing thoracotomy. Complete dissection of the hilum confirmed drainage of the middle and lower lobes to the left atrium. The anomalous vein was divided with a vascular stapler. The remainder of the resection and mediastinal lymphadenectomy were uneventful. Final pathology demonstrated a 3x2 cm adenocarcinoma in situ with negative margins and lymph nodes. She was discharged without issue a week after surgery.

DISCUSSION: Recognition of PAPVC at the time of lung resection prompted conversion to open lobectomy. A few points are worth consideration in this situation: 1) The anomaly was demonstrated on CT imaging, but was not detected preoperatively by the radiologist or the surgeon. The rarity of this condition, lack of symptoms, and focus on the oncologic aspects of the thoracic anatomy may have contributed to this oversight. 2) The resection likely could have been carried out thoracoscopically, but conversion to open was made due to unclear anatomy. 3) The PAPVC seemed thin-walled and more delicate than a normal pulmonary vein. 4) Fortunately, the tumor was in the lobe draining to the PAPVC, so that resection addressed the tumor and the anomalous drainage. If the tumor was not drained by the PAPVC, correction would likely be necessary to prevent worsening of left-to-right shunting.1

CONCLUSIONS: PAPVC is a rare anomaly that can persist into adulthood. It may lead to challenging clinical scenarios, especially if it presents with lung cancer. Preoperative identification is optimal to best plan the operation.

Chest. 2014;146(4_MeetingAbstracts):357A. doi:10.1378/chest.1989396