Seventy-eight patients underwent 107 carotid artery operations in which a decision to use an internal shunt was based solely upon the back pressure value distal to the proximally clamped internal carotid artery. The technique of back pressure measurement and angiographic correlation with back pressure values are described. Of the patients operated on, 89.7% had back pressures above 25 mm Hg and did not require a shunt. The validity of the test is confirmed as there were no deaths or strokes among the unshunted, neurologically intact, patients.
Patients with a neurologic deficit prior to operation have been identified as exceptions to the back pressure method. Four of 24 patients in this group experienced exacerbation of existing neurologic deficits following operation. We now recommend that an intraluminal shunt be used routinely for this special category.
Moore WS, Yee JM, Hall AD. Collateral Cerebral Blood PressureAn Index of Tolerance to Temporary Carotid Occlusion. Arch Surg. 1973;106(4):520-523. doi:10.1001/archsurg.1973.01350160134022