Intracranial post-clipping residual or recurrent aneurysms: Current status and treatment options (Review)

Abstract

Following the clipping of intracranial aneurysms, post-clipping residual or recurrent aneurysms (PCRRAs) can occur. In recent years, the incidence of PCRRAs has increased due to a prolonged follow-up period and advanced imaging techniques. However, several aspects of intracranial PCRRAs remain unclear. Therefore, the present study performed an in-depth review of the literature on PCRRAs. Herein, a summary of PCRRAs that can be divided into the following two categories is presented: i) Those occurring after the incomplete clipping of an aneurysm, where the residual aneurysm regrows into a PCRRA; and ii) those occurring after the complete clipping of an aneurysm, in which a de novo aneurysm occurs at the original aneurysm site. Currently, digital subtracted angiography remains the gold standard for the imaging diagnosis of PCRRAs as it can eliminate metallic clip artifacts. Intracranial symptomatic PCRRAs should be actively treated, particularly those that have ruptured. A number of methods are currently available for the treatment of intracranial PCRRAs; these mainly include re-clipping, endovascular treatment (EVT) and bypass surgery. Currently, re-clipping remains the most effective method used to treat PCRRAs; however, it is a very difficult procedure to perform. EVT can also be used to treat intracranial PCRRAs. EVT methods include coiling (stent- or balloon-assisted) and flow-diverting stents (or coiling-assisted). Bypass surgery can be selected for difficult-to-treat, complex PCRRAs. On the whole, following appropriate treatment, the majority of intracranial PCRRAs achieve a high occlusion rate and a good prognosis.

Keywords: endovascular treatment; post-clipping residual or recurrent aneurysms; surgical treatment.

Figure 1

Repeated subarachnoid hemorrhage following incomplete clipping. (A) Head CT scan illustrating subarachnoid hemorrhage at the suprasellar cistern. (B) CTA reveals an anterior communicating aneurysm (white arrow). (C) CT scan illustrating intraventricular hemorrhage from re-rupture of the anterior communicating aneurysm recurrent two months after microsurgical clipping. (D) Angiogram illustrating the aneurysm clip (white arrow) under the remnant aneurysm (black asterisk). For the case presented, the surgeon considered that complete clipping had been achieved. CT, computed tomography; CTA, computed tomography angiography.

Figure 2

Classification of intracranial PCRRAs. (A and B) Images show the development of a de novo aneurysm after clipping. (C and D) Images show a post-clipping residual aneurysm due to clip slippage. PCRRAs, post-clipping residual or recurrent aneurysms.

Figure 3

Coiling of the post-clipping recurrent aneurysm. (A) Brain CT scan illustrating subarachnoid hemorrhage at the suprasellar cistern; a metallic artefact can be seen. (B) Brain CTA illustrating the recurrent anterior communicating aneurysm; the clip can be seen (white arrow). (C) DSA of the left internal carotid artery illustrating the moyamoya-like vessels in the region of middle cerebral artery. (D) Three-dimensional DSA illustrating the recurrent anterior communicating aneurysm and the clip (white arrow). (E) Unsubtracted and (F) subtracted angiogram illustrating that the aneurysm is coiled completely. For the case presented in the image, the first clipping was performed five years ago. CT, computed tomography; CTA, computed tomography angiography; DSA, digital subtraction angiography; L, left; R, right.