False localization of rupture site in patients with multiple cerebral aneurysms and subarachnoid hemorrhage

OBJECTIVE: Patients with subarachnoid hemorrhage and multiple intracranial aneurysms present a unique challenge to the neurosurgeon. Unless all aneury sms can be clipped through a single craniotomy, the surgeon must accurately determine which aneurysm has ruptured. Misjudgment may result in disastrou s postoperative rebleeding from the untreated but true ruptured lesion. We assessed the risk of false localization of the rupture site and subsequent rebleeding and documented the problems in predicting the true rupture site when patients have multiple intracranial aneurysms. METHOD: We reviewed the records of a consecutive series of 93 patients trea ted over a period of 12 years who presented with their first subarachnoid h emorrhage and who had multiple intracranial aneurysms. The rupture site was determined on the basis of computed tomographic and angiographic findings, and the supposed ruptured aneurysm was clipped within 2 days of hemorrhage in each patient. Additional aneurysms that could not be accessed in the sa me surgical session were operated on at a later stage. All patients' record s were reviewed, and all computed tomographic scans and angiograms, includi ng repeat studies performed in some patients, were retrospectively reevalua ted by the authors, who had no knowledge of the patients' clinical informat ion. RESULTS: The location of the aneurysm that ruptured was verified at the tim e of surgery or during the autopsy in 76 patients (82%). The aneurysm that ruptured was the one predicted as ruptured by the surgeon before surgery in 69 patients (91%) and in retrospect in 72 patients (95%). Five of the 6 pa tients in whom the ruptured aneurysm was not correctly identified were thou ght to have only a single aneurysm. Four patients rebled after surgery, and 2 patients died as a result of the rebleeding. CONCLUSION: In the reported series, the most common cause of rebleeding soo n after aneurysm surgery was failure to obliterate the ruptured aneurysm, u sually because it was missed on the initial angiogram. The results support not only meticulous radiological investigation of all intracranial arteries before surgery but also thorough surgical inspection of the target aneurys m in all cases of subarachnoid hemorrhage even after one candidate lesion h as been discovered.