Figure 3From: Left upper lobectomy can be a risk factor for thrombosis in the pulmonary vein stump The hypothesis of a thrombus in the pulmonary vein stump after lobectomy. In a short PV stump, blood flow may occur because that in the left atrium spreads throughout the stump. In the long PV stump, turbulent flow or stasis of blood may occur because blood flow in the left atrium does not spread throughout the stump.Back to article page