The Accuracy of Plain Skull X-ray Examination as a Predictor of Recanalization Following Guglielmi Detachable Coil Embolisation in the Treatment of Cerebral Aneurysms

Usefulness of Craniograms in Discriminating Coiled Intracranial Aneurysms Requiring Retreatment

While endovascular coil embolization has become one of the major therapeutic modalities for intracranial aneurysms, long-term imaging follow-up is required because of the higher rate of retreatment compared with surgical clipping. The purpose of this study was to show the usefulness of craniograms to discriminate coiled intracranial aneurysms that required retreatment. Under the study protocol approved by institutional review board, a retrospective review of the medical record was done regarding coil embolization for intracranial aneurysms performed between January 2014 and December 2018. Coil embolization performed as the initial treatment and followed up for more than 1 year without additional treatment, and those performed as retreatment after the initial coil embolization performed at our institution were recruited. Craniograms obtained just after the initial treatment were compared with those obtained just before the additional treatment in the retreated cases and compared with the latest ones in the non-recurrence cases. Correlation between the morphological changes in the coil mass on the craniograms and retreatments was evaluated. During the study period, 288 coil embolization procedures for intracranial aneurysms were performed. From these, 191 treatments that were followed up for more than 1 year without any additional treatments and 30 retreatments were included. Morphological change of the coil mass was observed in 4 of the 191 non-recurrence treatments and 26 of the 30 retreatments, which was significantly correlated with retreatments (p <0.001). Craniogram was a useful modality in following up the coiled intracranial aneurysms to detect those required retreatments.

Utility of skull X-rays in identifying recurrence of coiled cerebral aneurysms

OBJECTIVE

A high rate of cerebral aneurysm recurrence following endovascular coiling has prompted the use of digital subtraction angiography (DSA) for interval follow-up. However, the utility of skull x-rays as an alternative screening method for aneurysm recurrence is unproperly characterized.

METHODS

Retrospective review of a prospective registry of ruptured and unruptured cerebral aneurysms. Anteroposterior and lateral skull x-rays were obtained immediately at the end of the procedure and at 6-month follow-up. Aneurysm recurrence was defined by comparing post-procedure and 6-month DSA imaging. A true positive was defined as a change in coil mass morphology on at least one projection with aneurysm recurrence on DSA, and a true negative defined as a stable coil mass on both projections and no recurrence on DSA. Receiver operating characteristic area under the curve (AUC) statistics was used to assess the performance of skull x-rays in identifying aneurysm recurrence.

RESULTS

A total of 118 cerebral aneurysms were evaluated with DSA imaging and skull x-rays. A change in coil mass morphology on one projection of skull x-rays correctly detected all true recurrences with a sensitivity of 100% (95% confidence interval [CI], 91-100%). Skull x-rays failed to identify a stable aneurysm coil mass in 15 cases, with a specificity of 79% (68-88%). Skull x-rays performed with AUC 0.8958 (95% CI, 0.8490-0.9431) in identifying aneurysm recurrence.

CONCLUSIONS

The findings of our study suggest that skull x-rays may represent a lowcost, non-invasive screening tool to rule out aneurysm recurrence, which can potentially aid in decreasing the utilization of DSA in the follow-up of patients with coiled cerebral aneurysms.

Comparison of the association of sac growth and coil compaction with recurrence in coil embolized cerebral aneurysms

Background and Purpose

In recurrent cerebral aneurysms treated by coil embolization, coil compaction is regarded as the presumptive mechanism. We test the hypothesis that aneurysm growth is the primary recurrence mechanism. We also test the hypothesis that the coil mass will translate a measurable extent when recurrence occurs.

Methods

An objective, quantitative image analysis protocol was developed to determine the volumes of aneurysms and coil masses during initial and follow-up visits from 3D rotational angiograms. The population consisted of 15 recurrence and 12 non-recurrence control aneurysms initially completely coiled at a single center. An investigator sensitivity study was performed to assess the objectivity of the methods. Paired Wilcoxon tests (p<0.05, one-tailed) were performed to assess for aneurysm and coil growth. The translation of the coil mass center at follow-up was computed. A Mann Whitney U-Test (p<0.05, one-tailed) was used to compare translation of coil mass centers between recurrence and control subjects.

Results

Image analysis protocol was found to be insensitive to the investigator. Aneurysm growth was evident in the recurrence cohort (p=0.003) but not the control (p=0.136). There was no evidence of coil compaction in either the recurrence or control cohorts (recurrence: p=0.339; control: p=0.429). The translation of the coil mass centers was found to be significantly larger in the recurrence cohort than the control cohort (p=0.047).

Conclusion

Aneurysm sac growth, not coil compaction, was the primary mechanism of recurrence following successful coil embolization. The coil mass likely translates to a measurable extent when recurrence occurs and has the potential to serve as a non-angiographic recurrence marker.

Efficacy of skull plain films in follow-up evaluation of cerebral aneurysms treated with detachable coils: quantitative assessment of coil mass

BACKGROUND AND PURPOSE

Skull plain films of coiled aneurysms have been used in a limited role, including morphologic comparison of the coil mass. We aimed to evaluate the efficacy of skull plain films in patients treated with detachable coils by using quantitative assessment.

MATERIALS AND METHODS

In this retrospective study, 78 pairs of the initial and follow-up skull anteroposterior and lateral images were reviewed independently by 2 neuroradiologists. The largest diameter, the perpendicular diameter, and area of the coil mass were measured separately on plain film, and quantitative changes of parameters were compared between subgroups, which were determined by consensus, depending on the need for retreatment. Subgroup analysis was also performed according to aneurysm size, packing attenuation, and ruptured status.

RESULTS

On skull lateral images, mean quantitative changes of the largest diameter (0.53 ± 0.43 mm versus 1.17 ± 0.91 mm, P < .01), the perpendicular diameter (0.56 ± 0.48 mm versus 1.20 ± 1.05 mm, P < .01), and the area of the coil mass (5.21 ± 7.51 mm(2) versus 10.55 ± 10.93 mm(2), P < .02) differed significantly between subgroups. Receiver operating characteristic analysis showed quantitative change of the largest diameter (>1.1 mm; sensitivity, 50.0%; specificity, 90.3%), the perpendicular diameter (>.9 mm; sensitivity, 62.5%; specificity, 85.5%), and the area (>8.5 mm(2); sensitivity, 50.0%; specificity, 83.9%) on skull lateral films to be indicative of aneurysm recurrence, and the diagnostic accuracy of these parameters increased significantly in the high-packing-attenuation group.

CONCLUSIONS

Quantitative measurement of the coil mass by using skull plain lateral images has the potential to predict aneurysm recurrence in follow-up evaluations of intracranial aneurysms with coiling.

[Neuroimaging follow-up of cerebral aneurysms treated with endovascular techniques]

There are no specific recommendations in clinical guidelines about the best time, imaging tests, or intervals for following up patients with intracranial aneurysms treated with endovascular techniques. We reviewed the literature, using the following keywords to search in the main medical databases: cerebral aneurysm, coils, endovascular procedure, and follow-up. Within the Cerebrovascular Disease Group of the Spanish Society of Neuroradiology, we aimed to propose recommendations and an orientative protocol based on the scientific evidence for using neuroimaging to monitor intracranial aneurysms that have been treated with endovascular techniques. We aimed to specify the most appropriate neuroimaging techniques, the interval, the time of follow-up, and the best approach to defining the imaging findings, with the ultimate goal of improving clinical outcomes while optimizing and rationalizing the use of available resources.

Aneurysm and Subarachnoid Haemorrhage

Although CT angiography is more and more widely used as diagnostic tool in SAH, DSA remains a useful technique. Indeed DSA is mandatory in patients with SAH and negative angio-CT, and in all other doubtful cases. Angiography is also necessary in order to perform an endovascular treatment. Sometimes, after a SAH a first angiogram may be normal due to spasm, haematoma or in case of a real perimesencephalic haemorrhage. The need for a second angiogram is discussed. Finally some aspects concerning the aneurysmal growth and rupture are also discussed.