Intracranial aneurysms: optimized diagnostic tools call for thorough interdisciplinary treatment strategies

Abstract

Objective: Intracranial aneurysms (IAs) require deliberately selected treatment strategies as they are incrementally found prior to rupture and deleterious subarachnoid haemorrhage (SAH). Multiple and recurrent aneurysms necessitate both neurointerventionalists and neurosurgeons to optimize aneurysmal occlusion in an interdisciplinary effort. The present study was conducted to condense essential strategies from a single neurovascular centre with regard to the lessons learned.

Method: Medical charts of 321 consecutive patients treated for IAs at our centre from September 2008 until December 2010 were retrospectively analysed for clinical presentation of the aneurysms, multiplicity and treatment pathways. In addition, a selective Medline search was performed.

Results: A total of 321 patients with 492 aneurysms underwent occlusion of their symptomatic aneurysm: 132 (41.1%) individuals were treated surgically, 189 (58.2%) interventionally; 138 patients presented with a SAH, of these 44.2% were clipped and 55.8% were coiled. Aneurysms of the middle cerebral artery were primarily occluded surgically (88), whereas most of the aneurysms of the internal carotid artery and anterior communicating artery (114) were treated endovascularly. Multiple aneurysms (range 2-5 aneurysms/individual) were diagnosed in 98 patients (30.2%). During the study period 12 patients with recurrent aneurysms were allocated to another treatment modality (previously clip to coil and vice versa).

Conclusions: Our data show that successful interdisciplinary occlusion of IAs is based on both neurosurgical and neurointerventional therapy. In particular, multiple and recurrent aneurysms require tailored individual approaches to aneurysmal occlusion. This is achieved by a consequent interdisciplinary pondering of the optimal strategy to occlude IAs in order to prevent SAH.

Keywords: clipping; coiling; interdisciplinary treatment; intracranial aneurysms.

Figure 1.

This histogram gives an overview on total number of patients, treatment modalities and subgroup distribution with regard to innocent intracranial aneurysms (IAs) and aneurysmal subarachnoid haemorrhage (SAH).

Figure 2.

A: Frontal projection DSA showing a regrowing aneurysm of the left pericallosal artery after two coiling occlusions; inset: coronal T2-weighted MRI showing the aneurysm. B: Lateral projection DSA showing a regrowing aneurysm; left inset: axial T1-weighted MRI; right inset: section of the removed and partially thrombosed aneurysm. C: Postoperative frontal projection DSA showing complete clipping of the aneurysm and the patent left pericallosal artery. D: Postoperative lateral projection DSA; inset: postoperative CT showing the clip. E: Intraoperative photograph: section of the aneurysm and removal of coils. F: Histological sectionof the aneurysm showing the thrombosed part and remaining coils. G: Close-up view of part F demonstrating the coils in more detail.

Figure 3.

Cross-over aneurysm of the anterior communicating artery (AcomA): after clipping, an incomplete occlusion of the aneurysmal base was diagnosed (A, bold arrow depicting the reminiscent aneurysm); the aneurysm could be occluded interventionally without stents (B1/B2, frontal view after coil embolization; C1/C2, lateral view after successful occlusion with the coils projecting underneath the clip).

Figure 4.

The total number of registered cases of both aneurysmal haemorrhage (ICD 10 of I60.x and I67.1; blue line) and unruptured aneurysms (red line) in Germany from 2000 to 2009. Note that even though the absolute number of SAH is decreasing, the frequency of newly diagnosed, unruptured aneurysms raises over the last decade (data source: Federal Statistical Office, branch Bonn).

Figure 5.

A simplified flowchart is suggested dividing decision making on IAs into two categories. (i) Innocent intracranial aneurysms (IAs) subgrouped into single and multiple IAs; an interdisciplinary discussion should occur as to whether coiling or surgical ligation would be most suitable for aneurysmal occlusion is mandatory. Potential complications and presumed morbidities (surgical approach, thromboembolic complication by remodelling or stenting) are not embedded in the flowchart, even though they have to be discussed in detail prior to intervention. (ii) The subgroup of aneurysms presenting with SAH; similar to the situation for innocent aneurysms, an interdisciplinary evaluation of the best treatment option should occur. Any treatment option should be carried out within 72 hours to minimize the risk of an early re-bleeding and avoiding the time of onset of vasospasms and ischaemia. In the case of an accompanying haemorrhagic mass lesion intra- or extra-axially with impending uncal herniation, urgent surgical intervention remains the only treatment option and is, therefore, not embedded in the histogram.

Figure 6.

Initial CT scan showing SAH in the quadrigeminal cisterns (B), DSA elucidating an aneurysm of the pericallosal artery (C, bold circle) and a second aneurysm of the right MCA (D); the blood clot in the interhemispheric fissure (A, bold circle) was highly suspicious of a bleeding from the pericallosal aneurysm.

Figure 7.

Massive subarachnoid haemorrhage (SAH) in the quadrigeminal cisterns (A); digital subtraction angiography (DSA) revealing at least five aneurysms: basilar artery (D), left posterior communicating artery (PcomA) (C) and right middle cerebral artery (MCA) (B, two aneurysms: M1 and M2 segment); the distribution of blood was indicative of either basilar artery aneurysm or PcomA aneurysm as bleeding source; after discussion the basilar and PcomA aneurysms were interventionally occluded without remodelling or stenting, leaving the MCA aneurysms for second stage surgery (lower row: left, frontal view of loosely packed aneurysm of the superior cerebellar artery and dense packing of the basilar tip aneurysm; right, lateral view, bold arrows pointing to the coil-occluded aneurysms of the internal carotid artery [ICA] and basilar artery).