PURPOSE: To present a maneuver consisting of temporary blockage of the venous return to the heart for accurate deployment of thoracic aortic endoprostheses. TECHNIQUE: During endovascular repairs in the thoracic aorta, an occluding balloon was introduced through the femoral vein into the right atrium under transesophageal echocardiographic control. The venous return through the inferior vena cava was temporarily blocked to reduce aortic flow during device deployment. The technique was applied in 21 patients with various lesions of the thoracic aorta. Partial inflow occlusion resulted in a mean systolic pressure of 49+/-6 mmHg and lasted for 52+/-14 seconds. Cardiac function was comparable to the preocclusion state, and no arrhythmias or ischemic events were encountered. In 7 procedures, inotropic or vasoconstrictor support was necessary after deployment. No complications related to the venous system were observed. The endoprostheses were precisely deployed at the target site in all patients. CONCLUSIONS: The force of aortic flow often impairs precise deployment of thoracic endoprostheses, resulting in distal displacement. Partial inflow occlusion provides precise control over the extent and duration of the hypotensive period, allowing accurate deployment of thoracic endoprostheses.