Marieke E.S. Sprengers

Coiling of Intracranial Aneurysms A Systematic Review on Initial Occlusion and Reopening and Retreatment Rates

Background and Purpose— The proportion of incompletely occluded aneurysms after coiling varies widely between studies. To assess overall outcome of coiling, we systematically reviewed the literature to determine initial occlusion, reopening, and retreatment rates of coiled aneurysms according to predefined criteria and subgroups. Methods— We searched PubMed and EMBASE (January 1999 to September 2008) for studies of >50 coiled aneurysms. Two reviewers independently extracted data. We grouped studies reporting on only ruptured aneurysms, posterior circulation aneurysms, and studies with large proportions of aneurysms >10 mm to assess possible determinants for incomplete occlusion, reopening, and retreatment. Results— Forty-six studies totalling 8161 coiled aneurysms met inclusion criteria. Immediately after coiling, 91.2% (95% CI, 90.6% to 91.9%) of the aneurysms were adequately occluded. Aneurysm reopening occurred in 20.8% (95% CI, 19.8% to 21.9%) and retreatment was performed in 10.3% (95% CI, 9.5% to 11.0%). Reopening rate was lower in studies reporting on ruptured aneurysms only compared with all studies (11.4% versus 20.8%; relative risk, 0.55; 95% CI, 0.47 to 0.64) and higher in studies focusing on posterior circulation aneurysms compared with studies with >85% anterior circulation aneurysms (22.5% versus 15.5%; relative risk, 1.5; 95% CI,1.2 to 1.7). Regression analysis showed higher retreatment rates with increasing proportion of aneurysms >10 mm (β=0.252; 95% CI, 0.073 to 0.432). We could not find a relation between reopening and type of coils used. Conclusion— At follow-up, one fifth of all coiled intracranial aneurysms shows reopening of which half is retreated. Possible risk factors for aneurysm reopening are location in the posterior circulation and size >10 mm. To confirm our findings, a meta-analysis on individual well-reported patient data is desirable. # Supplemental Appendix {#article-title-2}Background and Purpose— The proportion of incompletely occluded aneurysms after coiling varies widely between studies. To assess overall outcome of coiling, we systematically reviewed the literature to determine initial occlusion, reopening, and retreatment rates of coiled aneurysms according to predefined criteria and subgroups. Methods— We searched PubMed and EMBASE (January 1999 to September 2008) for studies of >50 coiled aneurysms. Two reviewers independently extracted data. We grouped studies reporting on only ruptured aneurysms, posterior circulation aneurysms, and studies with large proportions of aneurysms >10 mm to assess possible determinants for incomplete occlusion, reopening, and retreatment. Results— Forty-six studies totalling 8161 coiled aneurysms met inclusion criteria. Immediately after coiling, 91.2% (95% CI, 90.6% to 91.9%) of the aneurysms were adequately occluded. Aneurysm reopening occurred in 20.8% (95% CI, 19.8% to 21.9%) and retreatment was performed in 10.3% (95% CI, 9.5% to 11.0%). Reopening rate was lower in studies reporting on ruptured aneurysms only compared with all studies (11.4% versus 20.8%; relative risk, 0.55; 95% CI, 0.47 to 0.64) and higher in studies focusing on posterior circulation aneurysms compared with studies with >85% anterior circulation aneurysms (22.5% versus 15.5%; relative risk, 1.5; 95% CI,1.2 to 1.7). Regression analysis showed higher retreatment rates with increasing proportion of aneurysms >10 mm (&bgr;=0.252; 95% CI, 0.073 to 0.432). We could not find a relation between reopening and type of coils used. Conclusion— At follow-up, one fifth of all coiled intracranial aneurysms shows reopening of which half is retreated. Possible risk factors for aneurysm reopening are location in the posterior circulation and size >10 mm. To confirm our findings, a meta-analysis on individual well-reported patient data is desirable.

3D Rotational Angiography: The New Gold Standard in the Detection of Additional Intracranial Aneurysms

BACKGROUND AND PURPOSE: During surgery of symptomatic aneurysms, additional small angiographic occult aneurysms are commonly found. With 3D rotational angiography (3DRA) small aneurysms are more easily depicted than with digital subtraction angiography (DSA). In this study we compare 3DRA with DSA in the depiction of small additional aneurysms. MATERIALS AND METHODS: Three hundred fifty 3D datasets of 1 vascular tree of 350 patients with at least 1 intracranial aneurysm on the dataset were re-evaluated for the presence of additional aneurysms by 2 observers in consensus. Two other observers, blinded to the 3D images, re-evaluated DSA images of the same 350 vascular trees for these additional aneurysms. Results were compared. RESULTS: In 350 3D datasets, 350 target aneurysms and 94 additional aneurysms were detected. The mean size of 94 additional aneurysms was 3.54 mm (median, 3; range, 0.5–17 mm). The proportion of aneurysms ≤3 mm was significantly higher in additional aneurysms (61 of 94, 65%) than in the target aneurysms (61 of 350, 17%) (χ2, P < .0001). Of 94 additional aneurysms, 27 (29%) were missed on DSA by both observers. The mean size of the missed aneurysms was 1.94 mm (median, 2; range, 0.5–4 mm). The proportion of aneurysms ≤3 mm in missed additional aneurysms (26 of 27, 96%) was significantly higher than that in all additional aneurysms (61 of 94, 65%) (χ2, P = .0035). The location of missed additional aneurysms was not different from the location of all additional aneurysms. CONCLUSION: 3DRA depicts considerably more small (≤3 mm) additional aneurysms than DSA. In selected patients, accurate detection of these aneurysms may have consequences for the choice of treatment technique and for the frequency and duration of imaging follow-up.

Diagnostic Accuracy of CT Angiography with Matched Mask Bone Elimination for Detection of Intracranial Aneurysms: Comparison with Digital Subtraction Angiography and 3D Rotational Angiography

BACKGROUND AND PURPOSE: Our aim was to determine the diagnostic accuracy of multisection CT angiography combined with matched mask bone elimination (CTA-MMBE) for detection of intracranial aneurysms compared with digital subtraction angiography (DSA) and 3D rotational angiography (3DRA). MATERIALS AND METHODS: Between January 2004 and February 2006, 108 patients who presented with clinically suspected subarachnoid hemorrhage underwent both CTA-MMBE and DSA for diagnosis of an intracranial aneurysm. Two neuroradiologists, independently, evaluated 27 predefined vessel locations in the CTA-MMBE images for the presence of an aneurysm. After consensus, diagnostic accuracy of CTA was calculated per predefined location and per patient. Interobserver agreement was calculated with κ statistics. RESULTS: In 88 patients (81%), 117 aneurysms (82 ruptured, 35 unruptured) were present on DSA. CTA-MMBE detected all ruptured aneurysms except 1. Overall specificity, sensitivity, positive predictive value, and negative predictive value of CTA-MMBE were 0.99, 0.90, 0.98, and 0.95 per patient and 0.91, 1.00, 0.97, and 0.99 per location, respectively. Sensitivity was 0.99 for aneurysms ≥3 mm and 0.38 for aneurysms <3 mm. Interobserver agreement for aneurysm detection was excellent (κ value of 0.92 per location and 0.80 per patient). CONCLUSION: CTA-MMBE is accurate in detecting intracranial aneurysms in any projection without overprojecting bone. CTA-MMBE has limited sensitivity in detecting very small aneurysms. Our data suggest that DSA and 3DRA can be limited to the vessel harboring the ruptured aneurysm before endovascular treatment, after detection of a ruptured aneurysm with CTA.

Time to Reperfusion and Treatment Effect for Acute Ischemic Stroke: A Randomized Clinical Trial

IMPORTANCE Intra-arterial treatment (IAT) for acute ischemic stroke caused by intracranial arterial occlusion leads to improved functional outcome in patients treated within 6 hours after onset. The influence of treatment delay on treatment effect is not yet known. OBJECTIVE To evaluate the influence of time from stroke onset to the start of treatment and from stroke onset to reperfusion on the effect of IAT. DESIGN, SETTING, AND PARTICIPANTS The Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN) was a multicenter, randomized clinical open-label trial of IAT vs no IAT in 500 patients. The time to the start of treatment was defined as the time from onset of symptoms to groin puncture (TOG). The time from onset of treatment to reperfusion (TOR) was defined as the time to reopening the vessel occlusion or the end of the procedure in cases for which reperfusion was not achieved. Data were collected from December 3, 2010, to June 3, 2014, and analyzed (intention to treat) from July 1, 2014, to September 19, 2015. MAIN OUTCOMES AND MEASURES Main outcome was the modified Rankin Scale (mRS) score for functional outcome (range, 0 [no symptoms] to 6 [death]). Multiple ordinal logistic regression analysis estimated the effect of treatment and tested for the interaction of time to randomization, TOG, and TOR with treatment. The effect of treatment as a risk difference on reaching independence (mRS score, 0-2) was computed as a function of TOG and TOR. Calculations were adjusted for age, National Institutes of Health Stroke Scale score, previous stroke, atrial fibrillation, diabetes mellitus, and intracranial arterial terminus occlusion. RESULTS Among 500 patients (58% male; median age, 67 years), the median TOG was 260 (interquartile range [IQR], 210-311) minutes; median TOR, 340 (IQR, 274-395) minutes. An interaction between TOR and treatment (P = .04) existed, but not between TOG and treatment (P = .26). The adjusted risk difference (95% CI) was 25.9% (8.3%-44.4%) when reperfusion was reached at 3 hours, 18.8% (6.6%-32.6%) at 4 hours, and 6.7% (0.4%-14.5%) at 6 hours. CONCLUSION AND RELEVANCE For every hour of reperfusion delay, the initially large benefit of IAT decreases; the absolute risk difference for a good outcome is reduced by 6% per hour of delay. Patients with acute ischemic stroke require immediate diagnostic workup and IAT in case of intracranial arterial vessel occlusion. TRIAL REGISTRATION trialregister.nl Identifier: NTR1804.

Curative Embolization of Brain Arteriovenous Malformations with Onyx: Patient Selection, Embolization Technique, and Results

BACKGROUND AND PURPOSE: A new curative embolization technique with Onyx for selected small and medium-sized superficially located brain AVMs was developed, which consists of obliteration of the nidus, including incremental occlusion of the draining veins. We report our first clinical results. MATERIALS AND METHODS: Between June 2008 and July 2011, 24 patients (7 women, 17 men; mean age, 41 years; range, 6–74 years) with AVMs were selected for curative embolization with Onyx. Presentation was hemorrhage in 14 and seizures in 10 patients. AVM location was frontal in 11, occipital in 6, parietal in 4, and temporal in 3. AVM size was a mean of 2.2 cm (median, 2; range, 1–3 cm). RESULTS: Complete angiographic obliteration of the AVM with Onyx in a single session was achieved in all 24 patients. There were no hemorrhagic or ischemic complications (0%; 95% CI, 0%–16.3%), and no new deficits induced by the treatment. Of 14 patients with ruptured AVMs, 1 patient who presented with a large frontal hematoma died shortly after surgical evacuation of the hematoma following complete embolization of a micro-AVM. Follow-up angiography at 3 months in 23 patients demonstrated a small AVM remnant in 1 that was treated with gamma knife radiosurgery. The other 22 AVMs remained completely occluded. CONCLUSIONS: In selected patients with small and medium-sized superficial brain AVMs, as defined in our study, injection of Onyx by using a curative embolization technique in a single session seems to provide a safe and effective alternative to radiosurgery or surgery.

Long-Term Recurrent Subarachnoid Hemorrhage After Adequate Coiling Versus Clipping of Ruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE Coiling is increasingly used as treatment for intracranial aneurysms. Despite its favorable short-term outcome, concerns exist about long-term reopening and inherent risk of recurrent subarachnoid hemorrhage (SAH). We hypothesized a higher risk for recurrent SAH after adequate coiling compared with clipping. METHODS Patients with ruptured intracranial aneurysms coiled between 1994 and 2002 with adequate (>90%) aneurysm occlusion at 6-month follow-up angiograms were included. We interviewed these patients about new episodes of SAH. By survival analysis, we assessed the cumulative incidence of recurrent SAH after coiling and compared it with the incidence of recurrent SAH in a cohort of 748 patients with clipped aneurysms by calculating age and sex-adjusted hazard ratios. RESULTS Of 283 coiled patients with a total follow-up of 1778 patient-years (mean, 6.3 years), one patient had a recurrent SAH (0.4%) and 2 patients had a possible recurrent SAH. For recurrent SAH within the first 8 years after treatment, the cumulative incidence was 0.4% (95% CI, -0.4 to 1.2) after coiling versus 2.6% (95% CI, 1.2 to 4.0) after clipping (hazard ratio, 0.2; 95% CI, 0.03 to 1.6). For possible and confirmed recurrent SAH combined, the cumulative incidence was 0.7% (95% CI, 0.3 to 1.7) after coiling versus 3.0% (95% CI, 1.3 to 4.6) after clipping (hazard ratio, 0.7; 95% CI, 0.2 to 2.3). CONCLUSIONS Patients with adequately occluded aneurysms by coiling at short-term follow-up are at low risk for recurrent SAH in the long term. Within the first 8 years after treatment, the risk of recurrent SAH is not higher after adequate coiling than after clipping.

MR Angiography Follow-Up 5 Years after Coiling: Frequency of New Aneurysms and Enlargement of Untreated Aneurysms

BACKGROUND AND PURPOSE: Patients with intracranial aneurysms are at risk for future development of new aneurysms and growth of additional untreated aneurysms. Because in previous long-term studies duration of follow-up varied widely, the time interval after which screening could be effective remains largely unknown. The purpose of this study was to assess the incidence of de novo aneurysm formation and the growth of additional untreated aneurysms in patients with coiled aneurysms followed up with MR angiography (MRA) after a fixed period of 5 years. MATERIALS AND METHODS: In 65 patients with coiled intracranial aneurysms, high-resolution 3T MRA was performed 5.1 ± 0.2 years after coiling. MRA follow-up imaging was compared with MRA or CT angiography at the time of coiling. Additional aneurysms detected at MRA follow-up were classified as unchanged, grown, de novo, or incomparable with previous imaging. RESULTS: In 13 of 65 patients (20%), 24 additional aneurysms were found. Four aneurysms were incomparable with previous imaging and 2 of these were clipped. Of the remaining 20 additional aneurysms, 1 was de novo, 1 had grown slightly, and 18 were unchanged. The incidence of de novo aneurysm formation after 5 years was 1.54% (95% confidence interval, 0.01–9.0%). For additional aneurysms known at the time of initial coiling and for the 1 de novo aneurysm, no treatment was indicated. CONCLUSIONS: MRA screening 5 years after coiling for detection of de novo aneurysms and growth of additional untreated aneurysms has a low yield in terms of finding aneurysms that need to be treated.

Fenestrations of Intracranial Arteries Detected with 3D Rotational Angiography

BACKGROUND AND PURPOSE: Fenestrations of intracranial arteries are variants resulting from incomplete fusion of primitive vessels. An association with aneurysms is suggested in many studies. On conventional angiography, fenestrations are rarely visible. 3D rotational angiography (3DRA) provides improved visualization of cerebral vessels from any desired angle. We used 3DRA to assess the frequency and location of fenestrations of intracranial arteries and a possible relationship with aneurysms. MATERIALS AND METHODS: In 208 patients with suspected intracranial aneurysms, 3DRA of 1, 2, or 3 cerebral vessels (in 143, 16, and 49 patients) was reviewed for the presence and location of fenestrations and aneurysms. When fenestrations were present in combination with aneurysms, we noted the relationship of the locations. RESULTS: In 59 of 208 patients, 61 fenestrations were detected (28%). Fenestrations were more frequent in the anterior than in the posterior circulation (23% versus 7%), and the most common location was the anterior communicating artery (AcomA) (43 of 61, 70%). The frequency of fenestrations in 185 patients with aneurysms was not different from the frequency in 23 patients without aneurysms. Of 220 aneurysms present in 208 patients, 10 aneurysms (4.5%) were located on a fenestration. Of 61 fenestrations, 51 (84%) were not associated with an aneurysm. CONCLUSIONS: With 3DRA, fenestrations were found in 28% of patients. In our study, fenestrations occurred more often in the anterior than in the posterior circulation, and the most common location was the AcomA. A definite relationship between fenestrations and aneurysms cannot be concluded from our data.

Intracranial Aneurysms Treated with Coil Placement: Test Characteristics of Follow-up MR Angiography—Multicenter Study

PURPOSE To determine the test characteristics of magnetic resonance (MR) angiography in the assessment of occlusion of aneurysms treated with coil placement. MATERIALS AND METHODS This was an ethics committee-approved multicenter study. written informed consent was obtained in 311 patients with 343 aneurysms, who had been treated with coil placement and were scheduled for routine follow-up with intraarterial digital subtraction angiography (DSA). Thirty-five patients participated two or three times. Either 3.0- or 1.5-T time-of-flight (TOF) and contrast material-enhanced MR angiography were performed in addition to intraarterial DSA. Aneurysm occlusion was evaluated by independent readers at DSA and MR angiography. The test characteristics of MR angiography were assessed by using DSA as the standard. The area under the receiver operating characteristic curve (AUC) was calculated for 3.0- versus 1.5-T MR angiography and for TOF versus contrast-enhanced MR angiography, and factors associated with discrepancies between MR angiography and DSA were assessed with logistic regression. RESULTS Aneurysm assessments (n = 381) at DSA and MR angiography were compared. Incomplete occlusion was seen at DSA in 88 aneurysms (23%). Negative predictive value of MR angiography was 94% (95% confidence interval [CI]: 91%, 97%), positive predictive value was 69% (95% CI: 60%, 78%), sensitivity was 82% (95% CI: 72%, 89%), and specificity was 89% (95% CI: 85%, 93%). AUCs were similar for 3.0- (0.90 [95% CI: 0.86, 0.94]) and 1.5-T MR (0.87 [95% CI: 0.78, 0.95]) and for TOF MR (0.86 [95% CI: 0.81, 0.91]) versus contrast-enhanced MR (0.85 [95% CI: 0.80, 0.91]). A small residual lumen (odds ratio, 2.1 [95% CI: 1.1, 4.3]) and suboptimal projection at DSA (odds ratio, 5.5 [95% CI: 1.5, 21.0]) were independently associated with discordance between intraarterial DSA and MR angiography. CONCLUSION Documentation of good diagnostic performance of TOF MR angiography at both 1.5 and 3.0 T in the current study represents an important step toward replacing intraarterial DSA with MR angiography in the follow-up of patients with aneurysms treated with coils.

Collateral Status on Baseline Computed Tomographic Angiography and Intra-Arterial Treatment Effect in Patients with Proximal Anterior Circulation Stroke

Background and Purpose— Recent randomized trials have proven the benefit of intra-arterial treatment (IAT) with retrievable stents in acute ischemic stroke. Patients with poor or absent collaterals (preexistent anastomoses to maintain blood flow in case of a primary vessel occlusion) may gain less clinical benefit from IAT. In this post hoc analysis, we aimed to assess whether the effect of IAT was modified by collateral status on baseline computed tomographic angiography in the Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands (MR CLEAN). Methods— MR CLEAN was a multicenter, randomized trial of IAT versus no IAT. Primary outcome was the modified Rankin Scale at 90 days. The primary effect parameter was the adjusted common odds ratio for a shift in direction of a better outcome on the modified Rankin Scale. Collaterals were graded from 0 (absent) to 3 (good). We used multivariable ordinal logistic regression analysis with interaction terms to estimate treatment effect modification by collateral status. Results— We found a significant modification of treatment effect by collaterals (P=0.038). The strongest benefit (adjusted common odds ratio 3.2 [95% confidence intervals 1.7–6.2]) was found in patients with good collaterals (grade 3). The adjusted common odds ratio was 1.6 [95% confidence intervals 1.0–2.7] for moderate collaterals (grade 2), 1.2 [95% confidence intervals 0.7–2.3] for poor collaterals (grade 1), and 1.0 [95% confidence intervals 0.1–8.7] for patients with absent collaterals (grade 0). Conclusions— In MR CLEAN, baseline computed tomographic angiography collateral status modified the treatment effect. The benefit of IAT was greatest in patients with good collaterals on baseline computed tomographic angiography. Treatment benefit appeared less and may be absent in patients with absent or poor collaterals. Clinical Trial Registration— URL: http://www.trialregister.nl and http://www.controlled-trials.com. Unique identifier: (NTR)1804 and ISRCTN10888758, respectively.