ORIGINAL PAPER/ARTYKUŁ ORYGINALNYAssessment of long-term results of intracranial aneurysm clipping by means of computed tomography angiographyOcena skuteczności klipsowania tętniaków wewnątrzczaszkowych w terminie odległym za pomocą angiografii tomografii komputerowej
Introduction
The gold standard for the detection of cerebral aneurysms and also for checking the accuracy of aneurysm clipping is digital subtraction angiography (DSA) [1]. However, due to its invasiveness, DSA has not been widely used as a follow-up examination to assess the long-term effectiveness of aneurysm clipping [2]. The introduction of computed tomography angiography (CTA) for detecting intracranial aneurysms has made it possible to limit the invasiveness of the diagnostics, compared to DSA. High sensitivity and specificity of CTA have recently been proven for detecting very small aneurysms [3, 4] and as a useful diagnostic modality to check aneurysm occlusion after clipping [5, 6]. Due to simplicity and availability, CTA is now widely used in the diagnosis of patients after subarachnoid haemorrhage (SAH), and the use of this method is encouraged to control the completeness of aneurysm clipping. A similar trend toward less invasive methods can be seen in interventional radiology, where the long-term results of coiling can be effectively evaluated with magnetic resonance angiography (MRA) instead of DSA [7].
Knowledge of remote results of aneurysm clipping is mandatory, due to the development of endovascular modalities. Several years ago, the neurosurgical community demanded from interventional radiologists a long-term evaluation of coiling effectiveness. Currently, this is well documented [7] and it should be balanced by an objective assessment of clipping durability. Thus, we initiated long-term follow-up examinations in patients after aneurysmal subarachnoid haemorrhage treated by clipping. The aim of the study was to evaluate the efficacy and durability of clipping by means of a CTA examination performed many years after surgery.
Section snippets
Material and methods
Patients were qualified for this retrospective study if at least three years had passed since the clipping of ruptured intracranial aneurysm. Exclusion criteria were severe general and neurological conditions at the time of discharge from hospital. Invitations for a follow-up CTA examination were sent to 208 patients who underwent surgery between 1998 and 2005. The clips used before 1998, made of a different alloy, caused significant artefacts in CTA scans that hindered adequate evaluation of
Results
We did not observe any complications after intravenous administration of the contrast medium. In all but one patient, good quality CTA images were obtained, suitable for the evaluation of arteries around the clip site. In one case, significant artefacts around the clips were visible, but in spite of this, aneurysm regrowth was clearly visible, and so the patient was not excluded from the analysis. Of the 143 clipped aneurysms in 137 (96%) cases, complete aneurysm closure without residual neck
Clip slippage
In one case (0.7%) a total clip dislocation from the aneurysm dome was found (Fig 1I). The aneurysm was located on AComA. For accurate interpretation, the follow-up CTA was compared with preoperative CTA and the surgery report was also analysed. In the preoperative study, the aneurysm looked the same. There was no inconsistency between preoperative CTA and the intraoperative image. There were no rebleeding episodes and no perceptible enlargement of the aneurysm during 3 years of follow-up. The
Aneurysm re-rupture
Only one (0.7%) case of recurrent SAH was noted during the period of interest. This patient underwent surgery for ruptured AComA aneurysm 11 years ago. The cause of rebleeding was aneurysm regrowth at the site of previous clipping (Fig 1G-H). The recurrent SAH and source of rebleeding were established based on clinical symptoms, CT scan and CTA examination. The patient was operated on again. During the same procedure the aneurysm regrowth and unruptured ‘de novo’ MCA aneurysm were clipped and
Neck remnants
In 4 (2.8%) cases, neck remnants were detected. Two of them were located on AComA and two on MCA (Fig 1D-F). However, we cannot be sure whether these findings were definitely remnants or regrowths, because early vascular imaging was not performed. On the other hand, based on an analysis of preoperative aneurysm shape and operative descriptions, we assume that small remnants could remain in these cases. This could be expected due to a complex anatomical configuration and the narrowing of the
Durability of aneurysm clipping
In the past, the only examination for evaluation of the efficacy of aneurysm clipping was DSA. However, DSA has not been widely performed in long-term follow-up due to its invasiveness. Over the last two decades, more publications on this topic have appeared because of the need for comparison of the efficacy of two modalities: clipping and coiling [8, 9, 10, 11]. In a series of DSA performed in the Barrow Neurological Institute (Phoenix, USA) at a mean of 4.4 years post surgery, the overall
Conclusions
Computed tomography angiography is a simple and reliable method of aneurysm clipping evaluation. Long-term follow-up CTA confirmed permanent and complete obliteration in 96% of aneurysms. The rate of unsatisfactory aneurysm closure was 4%, but only 1.4% needed re-treatment during a mean follow-up of 6 years. The annual risk of rebleeding due to aneurysm regrowth was 0.1%. The satisfactory durability of clipping justifies long-term screening only in patients with risk factors for rebleeding.
Disclosure
Authors report no conflict of interest.
References (43)
- et al.
Methods and time schedule for follow-up of intracranial aneurysms treated with endovascular embolization: a systematic review
Neurol Neurochir Pol
(2011) - et al.
Postoperative three-dimensional CT angiography after cerebral aneurysm clipping with titanium clips: detection with single detector CT. Comparison with intra-arterial digital subtraction angiography
Clin Radiol
(2006) - et al.
Image quality and artefact generation post-cerebral aneurysm clipping using a 64-row multislice computer tomography angiography (MSCTA) technology: A retrospective study and review of the literature
Clin Neurol Neurosurg
(2010) - et al.
Noninvasive imaging of treated cerebral aneurysms, Part II: CT angiographic follow-up of surgically clipped aneurysms
AJNR Am J Neuroradiol
(2007) - et al.
What percentage of surgically clipped intracranial aneurysms have residual necks?
Neurosurgery
(2000) - et al.
Detection and characterization of very small cerebral aneurysms by using 2D and 3D helical CT angiography
AJNR Am J Neuroradiol
(2002) - et al.
Accuracy of 16-row multislice computed tomographic angiography for assessment of small cerebral aneurysms
Neurosurgery
(2008) - et al.
Comparison of multi-slice computerized tomography angiography and digital subtraction angiography in the postoperative evaluation of patients with clipped aneurysms
J Neurosurg
(2006) - et al.
Sixteen-row multislice computerized tomography angiography in the postoperative evaluation of patients with intracranial aneurysms
Br J Neurosurg
(2008) - et al.
Late angiographic follow-up review of surgically treated aneurysms
J Neurosurg
(1999)
Angiographic follow-up after surgical treatment of intracranial aneurysms
Acta Neurochir (Wien)
Risk of aneurysm recurrence in patients with clipped cerebral aneurysms: results of long-term follow-up angiography
Stroke
Natural history of the neck remnant of a cerebral aneurysm treated with the Guglielmi detachable coil system
J Neurosurg
Rates of delayed rebleeding from intracranial aneurysms are low after surgical and endovascular treatment
Stroke
International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised trial
Lancet
Longterm recurrent subarachnoid hemorrhage after adequate coiling versus clipping of ruptured intracranial aneurysms
Stroke
Long-term follow-up after treatment for cerebrovascular disease. Late follow-up review of clipped cerebral aneurysms
Surgery for Cerebral Stroke
CARAT Investigators. Predictors of rehemorrhage after treatment of ruptured intracranial aneurysms: the Cerebral Aneurysm Rerupture After Treatment (CARAT) study
Stroke
Yield of screening for new aneurysms after treatment for subarachnoid hemorrhage
Neurology
The Stockholm 20-year follow-up of aneurysmal subarachnoid hemorrhage outcome
Neurosurgery
Repeated screening for intracranial aneurysms in familial subarachnoid hemorrhage
Stroke
Cited by (7)
Incidence of Postoperative Cerebral Aneurysm Clip Slippage: Review of a Consecutive Case Series of 115 Clipped Aneurysms
2022, World NeurosurgeryCitation Excerpt :Nievas et al. reported a similar incidence of 2.7% in one study with 179 aneurysms, although patients without angiographic control were excluded from that study so a true incidence cannot be imputed.1 Kunert et al. reported a lower incidence of 1 case of clip slippage (0.7%) in a non-consecutive series of 143 clipped aneurysms out of 208 identified aneurysm clippings that underwent delayed CTA brain imaging after 3 to 11 years.10 Choi et al. reported no clip slippage in hand-selected 47 cases out of 3770 patients who were referred for aneurysms.11
Stent-assisted embolization of wide-neck anterior communicating artery aneurysms: Review of consecutive 34 cases
2016, Neurologia i Neurochirurgia PolskaCitation Excerpt :It may be one of the reasons the retreatment rate of 3.6% achieved in our study is comparatively low. This relatively aggressive approach is particularly applied in the treatment of the AcomA aneurysms, as it is documented that these aneurysms treated with microsurgical clipping are amongst those with the highest recurrence rate in comparison to aneurysms at other locations [25]. As it was demonstrated in the International Subarachnoid Aneurysm Trial (ISAT), angiographic occlusion rates of coiling in long-term follow-up are worse than the rates for microsurgical clipping [26].
Treatment strategies for saccular anterior inferior cerebellar artery aneurysms: a systematic review
2024, Neurosurgical ReviewFrequency and risk factors for postoperative aneurysm residual after microsurgical clipping
2021, Acta NeurochirurgicaStrategy of aneurysm clip angular adjustment during surgeries
2014, Chinese Journal of Cerebrovascular Diseases