What is the effect of carotid ligation on one side of the neck?

A long-term study of 43 patients with aneurysms at the posterior communicating artery (PCoA) which had resulted in subarachnoid hemorrhage (SAH) was carried out. Twenty-nine of them survived for more than 6 months after common carotid ligation following SAH, and the other 14, who were conservatively treated, survived for more than 6 months after the last SAH, which had occurred before admission. In 18 of the patients long-term follow-up was discontinued because of death (due to rebleeding or other causes), but all the remaining 25 patients are still in the follow-up study. The mean period of follow-up was 9 years and 9 months. The shortest period of follow-up was 1 year and the longest one was 17 years. Fatal rebleeding was observed in one of 19 patients who had had total ligation of the common carotid artery. Rebleeding was observed in six of 10 patients who had had partial ligation, and fatal rebleeding was later observed in four of these six patients. Rebleeding was observed in six of the 14 conservatively treated patients, and fatal rebleeding was later observed in five of these six patients. Two patients in whom an increase in the size of the aneurysm was angiographically observed during the follow-up after common carotid ligation underwent successful direct operations. Judging from the results of this study, it was certified that total ligation of the common carotid artery for ruptured PCoA aneurysms controls rebleeding more effectively than partial ligation or conservative treatment.