"Microbleeding" from intracranial aneurysms: Local hemosiderin deposition identified during microsurgical treatment of unruptured intracranial aneurysms

Abstract

Background:During elective surgery for unruptured aneurysms, we have identified a group of patients with hemosiderin staining of the pial surface immediately adjacent to the aneurysm dome suggesting a remote and unrecognized history of microbleeding from the aneurysm. These cases form the basis for this report.Methods:Medical records of 421 unruptured cerebral aneurysm patients treated surgically between January 2003 and September 2010 were retrospectively reviewed. Patients with a history of prior subarachnoid hemorrhage, craniotomy, or significant closed head injury were excluded from review. Records were reviewed for intraoperative descriptions of hemosiderin deposition in the vicinity of the aneurysm as well as history of headaches, time to presentation, comorbidities, aneurysm characteristics, procedures, and radiologic imaging.Results:Local hemosiderin staining immediately adjacent to the aneurysm was identified intraoperatively in 13 cases. Each of these patients had a history of remote atypical headache prior to presentation. Eight of these patients (62%) had aneurysms described as particularly “thin-walled” at the time of surgery. Aneurysm locations included the internal carotid artery (ICA) (54%), middle cerebral artery (MCA) (23%), anterior communicating artery (ACOMMA) (15%), and the anterior cerebral artery (ACA) (8%). More than half (54%) of these patients had a history of smoking, while 31% had hypertension, and 23% had a history of alcohol abuse. Dyslipidemia and family history of aneurysms were present in 15% and hypercholesterolemia was noted in one patient (8%).Conclusion:We suggest this group of patients had suffered a “microbleed” resulting in local hemosiderin deposition next to the aneurysm. The origins and clinical implications of such microbleeds are unknown and warrant further investigation.

Hemodynamic features of an intracranial aneurysm rupture predicted by perianeurysmal edema: A case report

“…[ 2 , 4 , 8 ] Hemosiderin deposition indicates minor leakage from a cerebral aneurysm. [ 7 , 14 ] In our case, bleeding occurred from a bleb buried in the left temporal lobe, which was accompanied by PAE. The morphological change in the rupture site bleb observed along evidence of hemosiderin deposition in this same region suggests sentinel bleeding.…”

The classification of intracranial aneurysm neck: a single center research experience

“…The most important goal in the treatment of intracranial aneurysms is to sustain the integrity and minimal occurrence of complications associated with intracranial aneurysm closure. Some studies report the incidence of microsurgical complications in patients with intracranial aneurysms, which is 2% to 5% [ 16 – 18 ].…”

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“…This is consistent with the previously published literature. Two studies (44,45) have confirmed that the bleeding rate of CMBs-related rupture is much higher than that in non-CMBs aneurysm patients. In addition, a review also suggested that compared with those with regular aneurysms, aneurysms with irregular shapes have a higher risk of rupture (46).…”