2019 Volume 33 Issue 1 Pages 58-62
As PAPVC, a rare vascular malformation, forms left-to right shunt, lobectomy exacerbates this shunt, and might cause right heart failure in cases with malformation located in the lobe that should be preserved. A 78-year-old man with PAPVC in the right upper lobe was referred to our hospital because of an abnormal shadow noted on a chest radiograph, suspected of being right lower lobe lung cancer. To simulate the exacerbation of the shunt after the lower lobectomy, a selective pulmonary artery (PA) occlusion test was conducted using a balloon catheter, which actually blocked the inferior pulmonary trunk simulating middle and lower lobectomy. The occlusion test was easier and stricter than the test blocking the lower pulmonary artery super selectively. The oxygen saturation was calculated using blood samples from the atrium and SVC (distal side of PAPVC) to measure O2 step up between those two anatomical sites. Although O2 step up deteriorated after PA occlusion from 3.2% initially to 6.2%, the value was less than 7%, being clinically significant. The calculated pulmonary blood flow/systemic blood flow ratio (Qp/Qs) after the PA occlusion test was 1.07, which was also less than 1.5 requiring a reconstructive vascular operation to reduce the shunt. Right lower lobectomy was performed without any complications as expected, and the patient was free from recurrence and any symptoms of right heart failure as of 2 years and 3 months after uneventful discharge.
