Computed Tomography Angiography Versus Digital Subtraction Angiography for Postclipping Aneurysm Obliteration Detection

Abstract

Background and Purpose— Digital subtraction angiography has been used as the gold standard to confirm successful aneurysmal obliteration after aneurysm clipping procedures using titanium or cobalt alloy clips. Computed tomographic angiography is a newer, less invasive imaging technique also used to confirm successful aneurysmal obliteration; however, its use compared with digital subtraction angiography remains controversial. Methods— A comprehensive literature search was conducted on Pubmed, EMBASE, and Cochrane databases through November 6, 2017, for studies that evaluated postclipping aneurysm obliteration with both computed tomographic angiography and digital subtraction angiography. Pooled sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR−) were calculated using the bivariate random-effects model. Results— Out of 6916 studies, 13 studies met inclusion criteria for this meta-analysis. A total of 510 patients with 613 aneurysms were included. Compared with digital subtraction angiography, which detected 87 residual aneurysms, computed tomographic angiography detected 58 resulting in a pooled sensitivity of 69% (95% CI, 54%–81%) and a pooled specificity of 99% (95% CI, 97%–99%). This corresponded to LR+ of 55.5 (95% CI, 23.6–130.9) and LR− of 0.31 (95% CI, 0.20–0.48). Univariate meta-regression revealed that the pooled sensitivity was worse in prospective designs ( P interaction <0.05), and the pooled specificity was better in higher-quality studies and for postoperative aneurysm diameters of <2 mm ( P interaction <0.001 for both). Conclusions— This meta-analysis revealed that computed tomographic angiography had a favorable LR+ but not a favorable LR−. Thus, this imaging modality may be applicable to rule in, but not rule out, residual aneurysms after clipping.

Efficacy of ultra-high-resolution computed tomographic angiography for postoperative evaluation of intracranial aneurysm after clipping surgery: A case report

“…Our results, measured using the noncontact-type X-ray analyzer, showed the effective X-ray energy at 120 kV as 55.9 keV and 48.8 keV in the UHR-CT and conventional CT used at our institute, respectively (unpublished data). A recent meta-analysis indicated that CTA was not as accurate as DSA in ruling out postclipping remnant aneurysms; [6] the reason is metal artifacts from titanium clips, which always matter in postoperative evaluations. [4] e current case report highlights that UHR-CTA is comparable with DSA in evaluating intracranial aneurysms even after the titanium clips were placed.…”

“…[1] However, aneurysmal clips induce metal artifacts in CTA, which hinder precise evaluations of aneurysms. [4,6] e ultra-high-resolution computed tomography (UHR-CT) system recently became available, and we recently reported usefulness of UHR-CT in the detection of the subcallosal artery. [5] UHR-CT theoretically reduces metal artifacts.…”

“…[ 3 ] Digital subtraction angiography (DSA) has long been considered the gold standard for examining cerebral aneurysms. [ 2 , 6 ] Recently, computed tomography angiography (CTA) has more frequently been used to evaluate aneurysms, especially after clipping surgeries. [ 1 ] However, aneurysmal clips induce metal artifacts in CTA, which hinder precise evaluations of aneurysms.…”

Noninvasive Angiographic Results of Clipped or Coiled Intracranial Aneurysms: An Inter- and Intraobserver Reliability Study

“…11,29 CTA of clipped aneurysms has generally not been as accurate compared with conventional angiography, especially for small aneurysms, when multiple clips were used, on small parent vessels, or when the aneurysm was in the vicinity of bony structures. 12,[30][31][32] These same technical limitations may explain the trend toward lower agreement for clipped aneurysm subgroups assessed by CTA compared with coiled aneurysms assessed by MRA.…”

“…9,10 When one judges the comparative success of therapy in clinical reports, it would seem that comparing CTA results of clipping with MRA results of coiling would be problematic, given the different diagnostic accuracies of the 2 modalities. 11,12 This problem is particularly relevant for clinical trials: We cannot require a catheter angiogram solely for the purposes of the study when safer, noninvasive tests clinically suffice for most patients. 13 The problem is compounded by the proliferation of grading scales, many of which are tailored to various devices and treatment modalities.…”