Simple Coiling versus Stent-Assisted Coiling of Paraclinoid Aneurysms: Radiological Outcome in a Single Center Study

Stent-Assisted Coiling in a Nickel-Allergic Patient

We report the case of a woman in her fourth decade of life with a known nickel allergy. She visited the previous clinic complaining of a headache. Head MRI was performed, which showed a right internal carotid artery aneurysm, and she was referred to our hospital for further treatment. We planned treatment using coiling embolization with a balloon catheter because we were afraid of allergic reactions against the nickel device. However, recused stenting was done during the procedure to prevent coil migration. After the treatment, there were no post-procedure neurological complications or hypersensitivity reactions due to nickel allergy. No medication was given to suppress the hypersensitivity reaction. The patient was discharged from the hospital with no complications. This case demonstrates that nickel-containing stents can be safely used in selected patients with confirmed nickel allergy.

Treatment of Paraclinoid Aneurysms With Stent-Assisted Coiling Versus Flow Diversion Techniques: A Systematic Review and Meta-Analysis

BACKGROUND

The stent-assisted coiling (SAC) and flow-diverter stent (FDS) techniques are widely used in the endovascular treatment of paraclinoid aneurysms. This article compares the occlusion rate, periprocedural complications, and clinical outcomes of SAC and FDSs.

METHODS

Between January 2010 and December 2020, a systematic search of electronic databases identified 2283 articles for screening. After the application of inclusion and exclusion criteria, data were extracted for a meta-analysis of the proportions.

RESULTS

Of 23 articles containing 4 comparative studies, 27 cohorts were included, and 1208 patients with 1328 aneurysms were analyzed: In 10 cohorts, 381 (28.7%) patients were treated with SAC, whereas in 17 cohorts, 947 (71.3%) patients were treated with FDSs. In the comparative studies, no significance was observed between the 2 treatments. In the pooled cohorts, complete occlusion was achieved in 85% of aneurysms after treatment with FDSs (95% CI: 0.81-0.88, I2=34.7%) and 76% after treatment with SAC (95% CI: 0.70-0.81, I2=16.6%); the subgroup analysis was statistically significant (P=0.003). New visual complications were observed in 5% of the FDS-treated group (95% CI: 0.02-0.09, I2=76.9%) and in 1% of the SAC-treated group (95% CI: 0.00-0.02, I2=0%); the subgroup analysis was statistically significant (P=0.018). Other observational indices, including total procedure-related complications; hemorrhagic, thrombotic, and ischemic complications; permanent morbidities, and favorable neurological outcomes, showed no statistical significance between the groups.

CONCLUSION

Compared with SAC, treatment with FDSs may have a higher complete occlusion rate at follow-up. The similarly low rates for procedure-related complications and permanent morbidities indicate that both treatments are safe. A higher rate of new visual complications was noted in the FDS-treated group. Further research is required for direct comparisons along with a complete ophthalmological examination.

Stent-assistant versus non-stent-assistant coiling for ruptured and unruptured intracranial aneurysms: A meta-analysis and systematic review

Background

Several different endovascular and non-invasive treatment methods are suggested for the various types of intracranial aneurysms including simple, balloon-assisted, and stent-assisted coiling (SAC). Previous studies investigated the safety and efficacy of SAC versus non-stent-assisted coiling (non-SAC) but the results were controversial. We aim to perform a systematic review and meta-analysis to compare the efficacy and safety of SAC with non-SAC technique in stratifying by the ruptured and unruptured aneurysms.

Methods

PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched in April 2022 for studies investigated the efficacy and safety of SAC versus non-SAC.

Results

Overall, 26 studies entered into our qualitative and quantitative synthesis. We found that there was overall lower recurrence rate in SAC versus non-SAC significant (RR: 0.43, 95%CI: 0.33, 0.53). Furthermore, the comparisons were significant in unruptured (RR: 0.63, 95%CI: 0.40, 0.86), ruptured (RR: 0.29, 95%CI), and combination aneurysms (RR: 0.42, 95%CI: 0.30, 0.54). Also, we found higher risk of intraprocedural rupture for SAC versus non-SAC in unruptured aneurysms (RR: 1.40, 95%CI: 1.31, 1.50). Investigating hemorrhagic events risk showed that there was significant difference in ruptured (RR: 1.73, 95%CI: 1.12, 2.34) and combination aneurysms (RR: 0.60, 95%CI: 0.37, 0.82). There was no significant difference in immediate occlusion rate, complete occlusion, and risk of ischemic events in our analysis.

Conclusion

Overall, our findings demonstrated that SAC may have higher efficacy in term of recurrence rate, but also may have a higher risk of complications in the treatment of intracranial aneurysms. As there are several factors affecting the outcomes and safety of these interventions, further RCTs controlled for multiple factors are required better guide the neurointerventionists choose the best strategy.

Endovascular Treatment and Microsurgical Clipping for the Management of Paraclinoid Intracranial Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVE

We aimed to compare the efficacy and safety of microsurgical clipping versus endovascular treatment (EVT) for paraclinoid aneurysms.

METHODS

A systematic search for studies including patients with paraclinoid aneurysms treated with a microsurgical or endovascular technique was conducted in 6 databases from inception to February 2022. Efficacy outcomes included complete angiographic occlusion at last follow-up, favorable functional outcome, and recurrence of the aneurysm. For safety, we assessed a composite of intraoperative and postoperative complications. Data were pooled using a random-effects model.

RESULTS

A total of 95 studies including 6711 patients, 3029 in the surgical group and 3682 in the EVT group were found. Pooled rates of complete occlusion were 94% (95% CI 91%-96%; I2 = 0%) in the surgical group and 69% (95% CI 63%-74%; I2 = 79%) in the EVT group, respectively. The favorable functional outcome rate was 86% (95% CI 76%-92%; I2 = 72%) with surgical treatment and 95% (95% CI 92%-97%; I2 = 61%) with EVT. The rate of aneurysm recurrence with surgical treatment was 1% (95% CI 0%-4%; I2 = 0%) and 12% (95% CI 9%-16%; I2 = 57%) with EVT. The composite safety outcome rate in the surgical group was 24% (95% CI 18%-30%; I2 = 90%) and 10% (95% CI 8%-13%; I2 = 71%) in the EVT group.

CONCLUSIONS

Our findings suggest that microsurgical clipping seems to have a higher efficacy than EVT in terms of angiographic occlusion and aneurysm recurrence; however, EVT seems to be safer in terms of intraoperative and postoperative complications. Considering the heterogeneity and low-level evidence of the data available, further prospective randomized studies are warranted to confirm our findings.

Safety and effectiveness of double microcatheter technique in the treatment of ruptured aneurysms of anterior cerebral circulation

Objective

To evaluate the safety and effectiveness of the double microcatheter technique in the treatment of ruptured aneurysms of the anterior cerebral circulation.

Methods

Between 2012 and 2019, 113 patients with ruptured aneurysms of the anterior cerebral circulation were treated using the double microcatheter technique. Clinical records, angiographic results, and procedure-related complications were reviewed. Clinical and angiographic follow-up was performed.

Results

Complete occlusion, neck remnant, and partial occlusion were, respectively, recorded in 56.6, 38.9, and 4.4% of the total cases. For all patients, the incidence of intraoperative complications was 5.3% (6/113), and the overall rate of morbidity was 10.6% (12/113). Before discharge, three patients (2.7%) died. There was no procedure-related mortality. At discharge, favorable outcomes were observed in 79.6% (90/113) of the patients. High Hunt-Hess grades and receiving a craniotomy or external ventricular drainage were risk factors for clinical outcomes at discharge. Clinical follow-up was performed in 91 patients at a mean interval of 14.07 ± 11.68 months. At follow-up, favorable outcomes were observed in 92.3% (84/91) of the patients. Angiographic follow-up was performed in 66 patients at an average of 11.53 ± 11.13 months. The recurrence rate was 37.9%. Of these patients, 13 (19.7%) received retreatment.

Conclusion

The double microcatheter technique can be performed in ruptured aneurysms with high technical success and low morbidity/mortality. However, recurrence remains a problem, and patients should be followed up regularly.

Endovascular Treatment for Lateral Wall Paraclinoid Aneurysms and the Influence of Internal Carotid Artery Angle

Lateral wall paraclinoid aneurysms (LPA) are a rare type of aneurysm located on the lesser curve side of the internal carotid artery (ICA) bend, at the level of the anterior clinoid process. The objective of this study was to assess the influence of flexion of the ICA on the morphology of aneurysms and outcome of endovascular treatment. Between 2003 and 2018, we treated 643 cases of unruptured paraclinoid aneurysms with endovascular therapy in our institution. Of those cases, aneurysms projecting laterally on preoperative angiography were defined as LPA. The degree of bending of the ICA (ICA angle) was measured and statistically analyzed in relation to the aneurysm characteristics and the occlusion status after treatment. In all, 43 aneurysms were identified. ICA angle was positively correlated with the maximum dome size of the aneurysm (P <0.01) and the aspect ratio (P <0.01), and negatively correlated with the volume coil embolization ratio (P <0.01). Complete occlusion (CO) was achieved in 23 cases (53.5%) immediately after treatment, and in 35 cases (81.4%) at follow-up. The mean ICA angle in the incomplete occlusion group was significantly larger than in the CO group (P = 0.01). Larger ICA angle resulted in recurrence, whereas smaller ICA angle was more likely to obtain progressive thrombosis (P = 0.02). Endovascular treatment for LPA was safe and effective. The degree of flexion of the ICA may contribute to the level of hemodynamic stress on the aneurysm, its morphology, and the embolization effect.

Association of Anterior Cerebral Artery Variants and Cerebral Infarction in Patients with Balloon-Assisted Coil Embolization for Unruptured Internal Carotid Artery Aneurysms

BACKGROUND

Balloon-assisted coiling (BAC) is an endovascular treatment that may be associated with increased complications and thromboembolic events compared with other coiling techniques. We compared clinical outcomes of endovascular treatment (simple coiling, stent-assisted coiling, and BAC) in patients with unruptured intracranial aneurysms at the internal carotid artery and assessed risk factors that could cause cerebral infarction in patients who underwent BAC.

METHODS

We retrospectively reviewed the records of 528 patients with 544 aneurysms who underwent endovascular treatment for unruptured intracranial aneurysms between January 2013 and November 2019. Demographic features, clinical information, balloon inflation time, fetal posterior cerebral artery, anterior cerebral artery (ACA) variants, and angiographic results were analyzed to determine risk factors for cerebral infarction.

RESULTS

There were no significant differences among the 3 groups in terms of general characteristics. In the BAC group, 14 of 39 patients showed a significantly higher incidence of cerebral infarction on diffusion magnetic resonance imaging compared with the stent-assisted coiling (37/238) and simple coiling (21/267) groups (P < 0.001). There was no significant difference between the ACA variants (normal vs. hypoplasia or aplasia) and cerebral infarction in the simple coiling and stent-assisted coiling groups, but the proportion of aplasia or hypoplasia in the BAC group was significantly higher (P = 0.001).

CONCLUSIONS

There is a significant association between anatomic ACA variants and cerebral infarction occurrence after BAC. Identifying the variant of the anatomic ACA using digital subtraction angiography would help to predict cerebral infarction after BAC.

Coil Embolization of Wide-Neck Bifurcation Aneurysms via Shouldering and Framing: A Safe Alternative to Conventional Techniques

OBJECTIVE

Double stent-assisted coiling of wide-neck bifurcation aneurysms (WNBAs) can be technically challenging with high thromboembolic rates. Single stent-assisted coiling (SSAC) decreases procedural complexity and thromboembolic risk but increases risk of coil prolapse and recanalization. In this study, we present our institution's experience with SSAC of WNBA performed via a "shouldering" and "framing" with a single Atlas stent and a spherical 3-dimensional (3D) Stryker coil.

METHODS

A retrospective review of 35 patients who underwent SSAC of WNBA performed via a shouldering and framing with a single Atlas stent and a spherical 3D Stryker coil from 2018 to 2019. Data collection were performed on baseline demographics, clinical presentation, aneurysm characteristics, angiographic and functional outcomes, and perioperative and postoperative complications.

RESULTS

Of 35 patients, the mean age was 59.9 ± 11.6 years and 25/35 (71.4%) were women. The mean aneurysm diameter was 6.3 ± 3.4 mm, the mean neck size was 3.9 ± 1.3 mm, and the mean dome-to-neck ratio was 1.5 ± 0.6. Initial complete/near-complete occlusion was demonstrated in 30/35 (85.7%) patients. On angiographic follow-up at a mean of 6 months, 9/24 (37.5%) patients showed progressive thrombosis, 13/24 (54.2%) showed stable occlusion, and 2/24 (8.5) showed recanalization. Thromboembolic events occurred in 2/35 (5.7%) patients, intraoperative technical complications occurred in 2/35 (5.7%) patients, and access-site complications occurred in 2/35 (5.7%) patients. The were no cases of retreatment, rehemorrhage, or procedural-related permanent morbidity or mortality.

CONCLUSIONS

Coil embolization performed via shouldering with a single Atlas stent and framing with a spherical 3D Stryker coil is a feasible, safe, and effective neuroendovascular treatment for WNBAs.

Hemodynamic Characteristics Associated With Paraclinoid Aneurysm Recurrence in Patients After Embolization

Objective: To investigate the hemodynamic features before and after embolization of paraclinoidal aneurysms using hemodynamic numerical simulation and the influence of embolization on recurrence after embolization.

Methods: From January 2016 to December 2017, we enrolled a total of 113 paraclinoidal aneurysms treated with embolization. They were divided into recurrent group and stable group depending on follow-up results. An aneurysm model was generated based on 3D-DSA before and after embolization. The hemodynamic characteristics were analyzed between two groups using Computational fluid dynamic (CFD).

Results: In the recurrent group, the peak systolic WSS, OSI and velocity around the aneurysm neck areas prior to embolization were 20.47 ± 3.04 Pa, 0.06 ± 0.02 and 0.07 ± 0.03 m/s, respectively. These values were 23.50 ± 4.11 Pa, 0.06 ± 0.01 and 0.11 ± 0.02 m/s, respectively in the stable group (P > 0.05). The WSS, OSI, velocity around the same areas in the recurrent group after embolization were 35.59 ± 8.75 Pa, 0.07 ± 0.02 and 0.12 ± 0.03 m/s, respectively (P < 0.01). In the stable group, the WSS, OSI and velocity were 13.08 ± 2.89 Pa, 0.04 ± 0.01 and 0.07 ± 0.02 m/s, respectively (P < 0.01). After embolization, the WSS, OSI and velocity around the aneurysm neck areas in the recurrent group were significantly higher than those in the stable group.

Conclusions: High peak systolic WSS, OSI and velocity around aneurysm neck areas after embolization of paraclinoidal aneurysms may be important factors leading to recurrence.

Progressive thrombosis of unruptured aneurysms after coil embolization: analysis of 255 consecutive aneurysms

Introduction

We have observed that aneurysms treated by insufficient coil embolization and filled with contrast agent immediately after the procedure are often completely occluded at follow-up. However, there are limited studies showing progressive thrombosis of aneurysms after coil embolization. Herein, we describe our experience with coil embolization for aneurysms, and discuss the factors involved in progressive thrombosis.

Methods

A total of 255 aneurysms treated by coil embolization in our institute between January 2011 and June 2017 and observed >6 months were included. ‘Progressive thrombosis’ indicated that aneurysms that were neck remnant (NR) or dome filling (DF) immediately after coil embolization changed to complete obliteration (CO) at the 6-month follow-up digital subtraction angiography. The factors involved in progressive thrombosis were assessed.

Results

In all aneurysms (n=255), 24 (9.4%) were CO, 82 (32.2%) were NR, and 149 (58.4%) were DF immediately after the procedure. At 6-month digital subtraction angiography, 123 (48.2%) were CO, 95 (37.3%) were NR, and 37 (14.5%) were DF. Retreatment for major recanalization was performed in eight cases (3.1%). One hundred and three aneurysms showed progressive thrombosis. There were significant differences in aneurysm location (P=0.0002), aneurysm dome diameter (P=0.0015), aneurysm neck diameter (P=0.0068), volume embolization ratio (P=0.0054), and endovascular procedure with stent (P=0.0264) between the progressive thrombosis and no thrombosis groups.

Conclusions

Progressive thrombosis can occur in aneurysms after coil embolization depending on aneurysm location and size, and stent use. Thus, the degree of coil embolization and combination with a stent should be adjusted depending on aneurysm type.

Loop microcatheter technique for coil embolization of paraclinoid aneurysms

BACKGROUND

Although paraclinoid aneurysms do not exhibit a high risk of rupture, coil embolization is not always easy because of unstable microcatheter position. We present a technique that allows a stable microcatheter position for coil embolization of paraclinoid aneurysms.

METHODS

We enrolled 34 consecutive patients who underwent coil embolization for paraclinoid aneurysms. A loop of distal microcatheter was shaped based on three-dimensional rotational angiography. The basic concept is to keep the proximal loop abutting the opposite wall of the aneurysm while using the distal loop for coiling. Then, a proximal curve was made to accommodate the shape of the carotid siphon, which may decide the direction of the loop. Stent-assisted coil embolization was performed in 19 wide-necked aneurysms. Immediate radiological outcomes were analyzed with Raymond classification and clinical outcomes were evaluated with modified Rankin Scale (mRS) scores.

RESULTS

Satisfactory occlusion of aneurysm was achieved in 94.1% (32/34) of patients with a Raymond score of 1 or 2. Packing density of ≥ 31% was achieved in 71% (24/34) of patients. No significant differences were observed between stent-assisted coiling and coiling-only groups. Follow-up magnetic resonance angiography and/or angiogram showed stable coil position, except in one patient with tiny recurrence (from Raymond scores 1 to 2) that did not require retreatment at the 6-month follow-up. mRS scores of 0-1 were obtained in all patients at 6 months.

CONCLUSIONS

Loop microcatheter technique allowed safe and stable coil packing for paraclinoid aneurysms. The same procedural concept is also being used for aneurysms in other vascular territories.