Postoperative three-dimensional CT angiography after cerebral aneurysm clipping with titanium clips: detection with single detector CT. Comparison with intra-arterial digital subtraction angiography

doi:10.1016/j.crad.2006.01.011

Clinical Radiology

Volume 61, Issue 6, June 2006, Pages 505-512

https://doi.org/10.1016/j.crad.2006.01.011 Get rights and content

AIM

To assess the significance of three-dimensional computed tomography angiography (3D-CTA) in detecting remnant necks after cerebral aneurysm clipping.

MATERIALS AND METHODS

A total of 59 patients (77 aneurysms) underwent surgery using titanium clips. Two blinded observers independently evaluated the presence of neck remnants on shaded-surface display (SSD) imaging, volume rendered (VR) imaging, and intra-arterial digital subtraction angiography (IADSA).

RESULTS

Mean sensitivity and specificity for detecting neck remnants were 50.0 and 74.2% for SSD imaging, 61.5 and 82.8% for VR imaging, and 92.3 and 92.2% for IADSA, respectively. Receiver operating characteristic (ROC) analysis revealed excellent diagnostic performance for IADSA [mean area under ROC curve (Az)=0.97], and good diagnostic performance for 3D-CTA (Az=0.70 and 0.76 for SSD and VR, respectively). Specificity of VR was better than that SSD (p=0.082), however, there was no significant difference between them.

CONCLUSION

Use of 3D-CTA techniques can facilitate postoperative evaluation.

Introduction

Conventional intra-arterial digital subtraction angiography (IADSA) is the reference standard for diagnostic work-up of cerebral aneurysm. However, less-invasive imaging techniques such as magnetic resonance angiography (MRA) and three-dimensional computed tomography angiography (3D-CTA) have been widely used for preoperative evaluation of cerebral aneurysm recently.1, 2, 3, 4, 5, 6, 7 Several authors have already noted that diagnostic accuracies of 3D-CTA are comparable to IADSA, particularly in medium-sized aneurysms≥3 mm.1, 2, 3, 4, 5, 6, 7

Postoperative confirmations of the clipped cerebral aneurysms are generally performed using IADSA, as the significant artefacts from surgical clips interfere with image quality of MRA and 3D-CTA after aneurysm surgery. Paramagnetic titanium clips for magnetic resonance imaging (MRI) have recently become widespread in clinical use. These clips are also expected to produce smaller artefacts, allowing evaluation using 3D-CTA after clipping surgeries.

A few studies comprising small numbers of patients or using phantoms have examined the usefulness of postoperative 3D-CTA evaluation for the clipped aneurysms.8, 9, 10, 11, 12 However, no clinical studies involving large patient populations have investigated the diagnostic accuracy of postoperative 3D-CTA. The present study determined the diagnostic accuracy of 3D-CTA using surface-shaded display (SSD) or volume rendering (VR), in the detection of neck remnants after aneurysmal clipping.

Section snippets

Materials and methods

Fifty-seven consecutive patients (77 aneurysms; 16 men, 41 women) who underwent clipping surgery for cerebral aneurysms in our hospital between April 1999 and December 2002 comprised the study group. The mean age of patients was 59.8 years (range, 40–74 years). The locations of the aneurysms are listed in Table 1. Patients were assessed using IADSA and 3D-CTA postoperatively. All patients underwent surgery using titanium alloy clips (Yasargil titanium aneurysm clip; Aesculap AG, Tüttlingen,

Diagnostic accuracy

A total of 13 neck remnants among the 77 clipped aneurysms (16.9%) were confirmed by consensus of the three neuroradiologists. Of these 13 remnant necks, three were 3–5 mm in diameter and 10 <3 mm. Complete closure of the aneurysm was achieved in the remaining 64 aneurysms (83.1%). Based on these results, the diagnostic accuracy of each imaging technique was assessed. In this study, grades 1 and 2 were regarded as indicating complete closure of the aneurysm, while grades 3–5 indicated incomplete

Efficacy of 3D-CTA after clipping surgery

Recent reports have indicated that preoperative 3D-CTA can detect even small aneurysms around 1 mm in diameter.7, 16 After surgical clipping of cerebral aneurysm, the existence of the neck remnant must be evaluated. Presence of the neck remnant is associated with a potential risk of aneurysm regrowth,17, 18, 19 and the frequency of re-rupture is reported as 3.7–27.8%.18, 20, 21 In addition, even if the aneurysms were completely clipped, there would be risks for the development of de novo

References (26)

R.B. Schwartz et al.
Evaluation of cerebral aneurysms with helical CT: correlation with conventional angiography and MR angiography
Radiology
(1994)
T. Ogawa et al.
Cerebral aneurysms: evaluation with three-dimensional CT angiography
AJNR Am J Neuroradiol
(1996)
J.N. Hsiang et al.
The role of computed tomographic angiography in the diagnosis of intracranial aneurysms and emergent aneurysm clipping
Neurosurgery
(1996)
G.B. Anderson et al.
Computed tomographic angiography versus digital subtraction angiography for the diagnosis and early treatment of ruptured intracranial aneurysms
Neurosurgery
(1999)
Y. Korogi et al.
Intracranial aneurysms: detection with three-dimensional CT angiography with volume rendering-comparison with conventional angiographic and surgical findings
Radiology
(1999)
P.M. White et al.
Intracranial aneurysms: CTA and MRA for detection prospective blinded comparison in a large patient cohort
Radiology
(2001)
Y. Kato et al.
Can 3D-CTA surpass DSA in diagnosis of cerebral aneurysm?
Acta Neurochir (Wien)
(2001)
P.T. Vieco et al.
CT angiography in the examination of patients with aneurysm clips
AJNR Am J Neuroradiol
(1995)
Y. Kato et al.
Effects of new titanium cerebral aneurysm clips on MRI and CT images
Minim Invasive Neurosurg
(1996)
J.J. van Loon et al.
Postoperative spiral computed tomography and magnetic resonance angiography after aneurysm clipping with titanium clips
Neurosurgery
(1997)

H.J. Steiger et al.

Virtues and drawbacks of titanium alloy aneurysm clips

Acta Neurochir (Wien)

(1999)

van der Schaaf I, van Leeuwen M, Vlassenbroek A, et al. Minimizing clip artifacts in multi CT angiography of clipped...

J.L. Fleiss

Statistical methods for rates and proportions

(1981)

Cited by (34)

Residual Cerebral Aneurysms After Microsurgical Clipping: A New Scale, an Agreement Study, and a Systematic Review of the Literature
2019, World Neurosurgery
The surgical repair of a cerebral aneurysm does not always lead to complete occlusion. A standardized repeatable method of reporting results of surgical clipping is desirable. Our purpose was to systematically review methods of classifying aneurysm remnants, provide a new scale with precise definitions of categories, and perform an agreement study to assess the variability in adjudicating remnants after aneurysm clipping.
A systematic review was performed to identify ways to report angiographic results of surgical clipping between 1963 and 2017. Postclipping angiographic results of 43 patients were also independently evaluated by 10 raters of various experience and backgrounds using a new 4-category scale. Agreement between responses were analyzed using κ statistics.
The systematic review yielded 63 articles with 37 different nomenclatures using 2–6 categories. The reliability of judging the presence of an aneurysm remnant on catheter angiography was studied only twice, with only 2 raters each time, with contradictory results. Interobserver agreement using the new 4-category scale was moderate (κ = 0.52; 95% confidence interval, 0.43–0.62) for all observers, but improved to substantial (κ = 0.62; 95% confidence interval, 0.47–0.76) when results were dichotomized (grade 0/1 vs. 2/3).
Various classification schemes to evaluate angiographic results after surgical clipping exist in the literature, but they lack standardization. Adjudication using fewer, better defined categories may yield more reliable agreement.
Assessment of long-term results of intracranial aneurysm clipping by means of computed tomography angiography
2013, Neurologia i Neurochirurgia Polska
Citation Excerpt :
A few comparative studies on CTA and DSA for the evaluation of aneurysm clipping have been published over the last decade. The sensitivity and specificity of CTA for detecting neck remnants were reported to be 60–100% and 83–100%, respectively [5,6,33–36]. Along with the development of new CT devices, high accuracy of CTA has recently been reported [5,6,37].
The aim of this retrospective study was to assess the effectiveness of aneurysm clipping by computed tomography angiography (CTA) in a long-term follow-up.
The CTA examination was performed in 119 patients who had 143 aneurysms clipped. The examinations were performed 3 to 11 years (mean 6 years) after clipping using a GE Lightspeed PRO16 scanner.
In all cases but one, good quality CTA images, suitable for evaluation of the arteries around the clip site, were obtained. Complete aneurysm closure without neck remnant or regrowth was confirmed in 137 (96%) aneurysms. In 4 (3%) cases, neck remnants were detected (2 on the anterior communicating artery [AComA] and 2 on the middle cerebral artery [MCA]). A total clip slippage from the aneurysm dome was revealed in 1 case. One case of aneurysm re-rupture was noted, 11 years after clipping. The rebleeding was caused by AComA aneurysm regrowth. Among these 6 patients with unsatisfactory clipping, 2 required further treatment and 4 remain under observation. Nineteen ‘de novo’ aneurysms in other locations were found in 14 (12%) patients. Summing up all of the pathological findings in the study group, there were 18 (15%) patients who needed further management including close surveillance or re-treatment.
Computed tomography angiography is a simple and reliable method of aneurysm clipping evaluation. The long-term follow-up CTA confirmed the permanent and complete obliteration of 96% of the 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 aneurysm re-rupture was 0.1%.
Celem niniejszej retrospektywnej pracy była ocena skuteczności klipsowania tętniaków wewnątrzczaszkowych w odległym terminie po operacji za pomocą angiografii tomografii komputerowej (angio-TK).
Angio-TK wykonano u 119 pacjentów ze 143 zaklipsowanymi tętniakami. Badania przeprowadzano w ciągu 3–11 lat od operacji (średnio 6 lat) aparatem CT GE Lightspeed PRO16.
U wszystkich pacjentów, poza jednym, uzyskano obrazy pozwalające na wiarygodną ocenę naczyń w pobliżu założonego klipsa. Spośród 143 zaklipsowanych tętniaków, w 137 (96%) przypadkach stwierdzono prawidłowe zamknięcie, bez cech odtwarzania się ani pozostałości tętniaka. Pozostałość szyi klipsowanego tętniaka (2 na tętnicy łączącej przedniej i 2 na tętnicy mózgu środkowej) stwierdzono w 4 przypadkach. W jednym przypadku uwidoczniono całkowite zsunięcie się klipsa z tętniaka tętnicy łączącej przedniej. W okresie objętym analizą zanotowano jeden przypadek nawrotowego krwotoku podpajęczynówkowego po 11 latach od operacji. Powodem był odrost tętniaka tętnicy łączącej przedniej. Spośród 6 chorych z niezadowalającym zaklipsowaniem, 2 wymagało dalszego leczenia, a 4 – obserwacji. U 14 (12%) pacjentów wykryto 19 tętniaków de novo w innych lokalizacjach, z których 18 nie wymagało leczenia. Biorąc pod uwagę wszystkie nieprawidłowości naczyniowe w badanej grupie, 18 (15%) pacjentów wymagało dalszej obserwacji lub leczenia.
W ocenie autorów angio-TK jest wygodnym i wiarygodnym sposobem kontroli po operacjach zaklipsowania tętniaka. Odległe badania angio-TK wykazały, że klipsowanie całkowicie i trwale wyłącza z krążenia 96% tętniaków. Odsetek niezadowalającego zaklipsowania wyniósł 4%, ale tylko 1,4% pacjentów wymagało dalszego leczenia w okresie obserwacji wynoszącym średnio 6 lat. Ryzyko ponownego krwotoku z zaklipsowanego tętniaka wyniosło 0,1% na rok.
Appearance and impact of post-operative intracranial clips and coils on whole-brain CT angiography and perfusion
2012, European Journal of Radiology
Citation Excerpt :
The availability of 160 mm of craniocaudal coverage allows for whole-brain data acquisition that can be viewed as a time-resolved 4D CT DSA and may also be deconvolved to create whole-brain CT perfusion (CTP) maps. While CT DSA and CTP have been utilized to evaluate risk factors for delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage and for postoperative outcomes following coiling and clipping [7–11], whole-brain CT DSA has only recently been explored as an alternative to conventional angiography. As researchers and clinicians consider the viability of CT DSA and CTP for this purpose, it is important to quantify the effect vascular clips and endovascular coils have on the CTP values of regional cerebral blood volume (CBV), regional cerebral blood flow (CBF), mean transit time (MTT), and time to peak (TTP).
To evaluate the effect of vascular clips and endovascular coils placed for intracranial aneurysms and arteriovenous malformations on whole-brain computed tomography (CT) angiography and perfusion.
A 320-detector row dynamic volume CT system imaged 11 patients following surgical placement of vascular clips or endovascular coils. The extent of clip and coil subtraction by automated software was evaluated using CT digital subtraction angiography and CT perfusion. Impact on CT perfusion values by retained intracranial devices was compared to age- and gender-matched controls.
Clip and coil subtraction on CT angiography was graded as good in 8 and moderate in 3 cases. A residual neck and additional aneurysm were noted in 1 of 11 patients. Post-procedural axial slice level CT perfusion values decreased in reliability with increasing proximity to the metallic devices secondary to beam hardening. However, the intracranial devices did not affect axial slice level CTP values of cerebral blood volume, cerebral blood flow and mean transit time outside of the level of the device. Time to peak values was globally decreased outside of the immediate vascular intervention region.
Advances in CT technology have provided clinically useful subtraction of intracranial clips and coils. While CT perfusion values were altered in device subtraction areas and within beam hardening artifact areas; they can provide valuable postoperative information on whole-brain hemodynamics. In selected cases, the combination of CT angiography and whole-brain CT perfusion can offer an alternative to conventional angiography that is a more invasive option.
Sixty-four-row multislice computed tomographic angiography in the diagnosis and characterization of intracranial aneurysms: Comparison with 3D rotational angiography
2011, World Neurosurgery
Sixty-four-row multislice computed tomographic angiography (CTA) has great potential for use in vascular studies. The aim of our study was to compare 64-slice CTA with three-dimensional rotational angiography (3DRA) in the detection and characterization of intracranial aneurysms with special attention to smaller (<3-mm) aneurysms.
In a prospective study, a total of 133 patients were included who successively underwent 64-slice CTA and digital subtraction angiography (DSA) examinations for suspected intracranial aneurysms. The 64-slice CTA, conventional DSA, and 3DRA images were independently reviewed by five readers who performed the presence, shape, dimension, and location of aneurysms. The 3DRA results were considered as the ultimate reference standard.
The reference standard revealed 111 aneurysms in 93 patients: 27 aneurysms were read as <3 mm, 66 were read as being between 3 and 8 mm, and 18 were read as >8 mm. The sensitivities of 64-slice CTA for aneurysms <3 mm, between 3 and 8 mm, and >8 mm were 96.3%, 98.5%, and 100%, respectively, on a per-aneurysm basis. The sensitivities of conventional DSA for aneurysms <3 mm, between 3 and 8 mm, and >8 mm were 85.2%, 100%, and 100%, respectively, on a per-aneurysm basis. The 64-slice CT angiographic images could clearly show the aneurysmal characteristics and the relationship between aneurysms and adjacent branch vessels.
Sixty-four-slice CTA is a highly accurate imaging examination of the first-line imaging technique for detecting and characterizing intracranial aneurysms including <3-mm aneurysms.
Applications of multislice CT angiography in the surgical clipping and endovascular coiling of intracranial aneurysms
2010, Journal of Biomedical Research
Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage (SAH). The aim of our study was to assess the clinical usefulness of multislice computed tomography an-giography (CTA) in the surgical and endovascular treatment of intracranial aneurysms. A total of 195 cases with 206 intracranial aneurysms underwent CTA. Fifty (24%) aneurysms underwent surgical clipping while 156 (76%) aneurysms underwent endovascular coiling. In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas, surgical treatment was successfully performed based on 16-slice CTA alone, and the other 36 aneurysms were clipped on the main basis of the CTA. The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully. Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and en-dovascular treatment of intracranial aneurysms.
Clinical application of 16-row multislice computed tomographic angiography in the preoperative and postoperative evaluation of intracranial aneurysms for surgical clipping
2009, Surgical Neurology
Citation Excerpt :
At some institutions, CTA has replaced DSA in the preoperative evaluations of patients with intracranial aneurysms [2,4,10,15]. At present, there have been numerous studies emphasizing the diagnostic accuracy of aneurysms by comparing multislice CTA with DSA [3,7,11,14,16]. Nevertheless, the purpose of our study was to evaluate the clinical application of 16-row multislice CTA in the preoperative and postoperative assessment of intracranial aneurysms for surgical clipping.
Sixteen-row multislice CTA has great potential for use in the studies of intracranial aneurysms. The aim of the study was to assess the clinical application of 16-row multislice CTA in the preoperative and postoperative evaluation of intracranial aneurysms for surgical clipping.
A total of 42 patients (45 aneurysms) underwent surgery using titanium clips. The CTA was performed with a 16-row multislice CT machine; detector slice, 0.75 mm; reconstruction interval, 0.40 mm; and timing determined by bolus trigger. The neuroradiologist independently evaluated the shape, size, and location of aneurysms; the relationship to other structures; and the presence of neck remnants and patency of the parent artery after clipping on MIP images, VR imaging, and thin-slab MIP and VR images.
Sixteen-slice CTA clearly provided the shape and location of aneurysms, the size of the sac and the neck, and the relationship of aneurysms to bone structures and adjacent branch vessels; and this information would help the neurosurgeons find aneurysms and clip them successfully. Three clipped aneurysms with neck remnants were identified by the 16-slice CTA, and the parent artery could be reliably evaluated close to the clip.
Sixteen-slice CTA is a useful reference for patients undergoing surgical clipping of aneurysms and can provide much effective information to clipped aneurysms.

View all citing articles on Scopus

View full text

Postoperative three-dimensional CT angiography after cerebral aneurysm clipping with titanium clips: detection with single detector CT. Comparison with intra-arterial digital subtraction angiography

AIM

MATERIALS AND METHODS

RESULTS

CONCLUSION

Introduction

Section snippets

Materials and methods

Diagnostic accuracy

Efficacy of 3D-CTA after clipping surgery

Evaluation of cerebral aneurysms with helical CT: correlation with conventional angiography and MR angiography

Radiology

Cerebral aneurysms: evaluation with three-dimensional CT angiography

AJNR Am J Neuroradiol

The role of computed tomographic angiography in the diagnosis of intracranial aneurysms and emergent aneurysm clipping

Neurosurgery

Computed tomographic angiography versus digital subtraction angiography for the diagnosis and early treatment of ruptured intracranial aneurysms

Neurosurgery

Intracranial aneurysms: detection with three-dimensional CT angiography with volume rendering-comparison with conventional angiographic and surgical findings

Radiology

Intracranial aneurysms: CTA and MRA for detection prospective blinded comparison in a large patient cohort

Radiology

Can 3D-CTA surpass DSA in diagnosis of cerebral aneurysm?

Acta Neurochir (Wien)

CT angiography in the examination of patients with aneurysm clips

AJNR Am J Neuroradiol

Effects of new titanium cerebral aneurysm clips on MRI and CT images

Minim Invasive Neurosurg

Postoperative spiral computed tomography and magnetic resonance angiography after aneurysm clipping with titanium clips

Neurosurgery

Virtues and drawbacks of titanium alloy aneurysm clips

Acta Neurochir (Wien)

Statistical methods for rates and proportions