Perioperative rupture risk of unruptured intracranial aneurysms in cardiovascular surgery

Although unruptured intracranial aneurysms are increasingly being diagnosed incidentally, perioperative rupture risk of unruptured intracranial aneurysm in patients undergoing cardiovascular surgery remains unclear. Therefore, we conducted an observational study to assess the prevalence and perioperative rupture risk of unruptured intracranial aneurysm in patients undergoing cardiovascular surgery. Adult patients (n = 4864) who underwent cardiovascular surgery between January 2010 and December 2016 were included. We assessed the prevalence of unruptured intracranial aneurysms in these patients using preoperative neurovascular imaging. The incidence of postoperative 30-day subarachnoid haemorrhage from aneurysmal rupture was investigated in patients undergoing cardiovascular surgery with unruptured intracranial aneurysm. Postoperative outcomes were compared between patients with unruptured intracranial aneurysm and those without unruptured intracranial aneurysm. Of the 4864 patients (39.6% females; mean ± standard deviation age, 62.3 ± 11.3 years), 353 patients had unruptured intracranial aneurysms (prevalence rate, 7.26%; 95% confidence interval, 6.52-8.06%). Of these, eight patients received surgical or endovascular treatment before surgery and 345 patients underwent cardiovascular surgery with unruptured intracranial aneurysms. Within 30 days postoperatively, subarachnoid haemorrhage occurred only in one patient, and the cumulative postoperative 30-day subarachnoid haemorrhage incidence was 0.29% (95% confidence interval, 0.01% to 1.61%). The Kaplan-Meier estimated subarachnoid haemorrhage probabilities according to the unruptured intracranial aneurysm rupture risk scores were not higher than the previously reported risk in the general population. There were no significant differences in postoperative subarachnoid haemorrhage-free survival, haemorrhagic stroke-free survival, in-hospital mortality, and hospital length of stay between patients with unruptured intracranial aneurysm and those without unruptured intracranial aneurysm. In conclusion, the prevalence of unruptured intracranial aneurysm in patients undergoing cardiovascular surgery is higher than in the general population. However, incidentally detected unruptured intracranial aneurysms are not linked to an increased risk of subarachnoid haemorrhage or adverse postoperative outcomes. These findings may help determine the optimal management of unruptured intracranial aneurysms before cardiovascular surgery.