Long-Term Causes of Death and Excess Mortality After Carotid Artery Ligation

Objective Carotid artery ligation (CAL) is used to treat large and complex intracranial aneurysms. However, little is known about long-term survival and causes of death in patients who undergo the procedure. This study was intended to evaluate if patients who have undergone CAL have long-term excess mortality and what the causes of death are. Methods All patients were treated at Helsinki University Hospital between 1937 and 2009. Patients who had undergone CAL and survived ≥1 year after the procedure were included in the cohort. Follow-up was until death or 2015 (2711 patient-years). Causes of death were reviewed and relative survival ratios calculated using the Ederer II method and a matched population. Results There was 12% excess mortality in all patients 20 years after CAL and 22% after 30 years. A higher proportion of the patients who had subarachnoid hemorrhage (SAH) died during follow-up compared with unruptured patients undergoing CAL. Cardiovascular disease and cerebrovascular accident were the leading causes of death. Conclusions Patients with unruptured aneurysms did not experience as much excess mortality as those who had an SAH. The higher proportion of deaths observed in ruptured patients may be partly because of long-term excess mortality conferred by the SAH itself or SAH risk factors. Although the entire population did display excess mortality compared with the general population, this may be because of shared risk factors for aneurysm development and rupture and the cause of death.