Eight patients with subclavian artery stenosis or occlusion and transient cerebral ischemia or brachial claudication were treated with a carotid-subclavian bypass. Intraoperative measurement of graft flow and carotid and subclavian pressure indicated restoration of subclavian pressure in all but one patient with a small vein graft. Graft flow increased from 149 ± 28 to 408 ± 55 ml/min with injection of 15 mg of papaverine hydrochloride into the graft. Carotid pressure did not fall when the graft was opened and fell an average of 2 mm Hg after papaverine. These hemodynamic observations support the use of carotid-subclavian bypass and indicate that the common carotid artery is adequate to supply the distal carotid and subclavian arteries unless there is proximal stenosis of the common carotid.
Barner HB, Kaiser GC, Willman VL. Hemodynamics of Carotid-Subclavian Bypass. Arch Surg. 1971;103(2):248–251. doi:10.1001/archsurg.1971.01350080164025