Ibrahim Tarik F, Hafez Ahmad, Andrade-Barazarte Hugo, Raj Rahul, Niemela Mika, Lehto Hanna, Numminen Jussi, Jarvelainen Juha, Hernesniemi Juha
Department of Neurosurgery, Helsinki University Hospital, Helsinki, Finland, USA ; Department of Neurosurgery, Loyola University Medical Center, Maywood, IL, USA.
Department of Neurosurgery, Helsinki University Hospital, Helsinki, Finland, USA.
Surg Neurol Int. 2015 Oct 23;6(Suppl 21):S560-5. doi: 10.4103/2152-7806.168074. eCollection 2015.
De novo intracranial aneurysms are reported to occur with varying incidence after intracranial aneurysm treatment. They are purported to be observed, however, with increased incidence after Hunterian ligation; particularly in cases of carotid artery occlusion for giant or complex aneurysms deemed unclippable.
We report a case of right-sided de novo giant A2 aneurysm 6 years after an anterior communicating artery (ACoA) aneurysm clipping. We believe this de novo aneurysm developed in part due to patient-specific risk factors but also a significant change in cerebral hemodynamics. The ACoA became occluded after surgery that likely altered the cerebral hemodynamics and contributed to the de novo aneurysm. We believe this to be the first reported case of a giant de novo aneurysm in this location. Following parent vessel occlusion (mostly of the carotid artery), there are no reports of any de novo aneurysms in the pericallosal arteries let alone a giant one. The patient had a dominant right A1 and the sudden increase in A2 blood flow likely resulted in increased wall shear stress, particularly in the medial wall of the A2 where the aneurysm occurred 2 mm distal to the A1-2 junction.
ACoA preservation is a key element of aneurysm surgery in this location. Suspected occlusion of this vessel may warrant closer radiographic follow-up in patients with other risk factors for aneurysm development.
据报道，颅内动脉瘤治疗后新发颅内动脉瘤的发生率各不相同。然而，据称在亨特结扎术后其发生率会增加；尤其是在因巨大或复杂动脉瘤无法夹闭而进行颈动脉闭塞的情况下。
我们报告一例在前交通动脉（ACoA）动脉瘤夹闭术后6年出现右侧新发巨大A2动脉瘤的病例。我们认为，这种新发动脉瘤的形成部分归因于患者特有的危险因素，也与脑血流动力学的显著变化有关。手术导致ACoA闭塞，这可能改变了脑血流动力学并促成了新发动脉瘤的形成。我们认为这是该部位首次报道的巨大新发动脉瘤病例。在母血管闭塞（主要是颈动脉）后，没有关于胼周动脉出现任何新发动脉瘤的报道，更不用说巨大动脉瘤了。该患者右侧A1优势，A2血流突然增加可能导致壁面剪应力增加，尤其是在A2内侧壁，动脉瘤发生在A1 - 2交界处远端2 mm处。
ACoA的保留是该部位动脉瘤手术的关键要素。对于有其他动脉瘤形成危险因素的患者，怀疑该血管闭塞可能需要更密切的影像学随访。
