Long-term radiographic results of stent-assisted embolization of cerebral aneurysms

Effect of Stent Porosity, Platelet Function Test Usage, and Dual Antiplatelet Therapy Duration on Clinical and Radiographic Outcomes After Stenting for Cerebral Aneurysms: A Meta-Analysis

BACKGROUND

The use of stents with various porosities for treating cerebral aneurysms requires dual antiplatelet therapy (DAPT) without clear guidelines on the utility of platelet function tests (PFTs) and the duration of DAPT. We sought to determine the effects of stent porosity, PFT usage, and DAPT duration on the radiographic and clinical outcomes after stenting of cerebral aneurysms.

METHODS

PubMed was searched on March 29, 2021 for studies of cerebral aneurysm stenting that had specified the stent type and DAPT duration. A random effects meta-analysis was used to measure the prevalence of nonprocedural thrombotic and hemorrhagic events, clinical outcomes, aneurysm occlusion, and in-stent stenosis stratified by stent porosity, PFT usage, and DAPT duration.

RESULTS

The review yielded 105 studies (89 retrospective and 16 prospective) with 117 stenting cohorts (50 high porosity, 17 intermediate porosity, and 50 low porosity). In the high-, intermediate-, and low-porosity stenting cohorts, PFT usage was 26.0%, 47.1%, and 62.0% and the mean DAPT duration was 3.51 ± 2.33, 3.97 ± 1.92, and 5.18 ± 2.27 months, respectively. The intermediate-porosity stents showed a reduced incidence of hemorrhagic events (π = 0.32%) compared with low-porosity stents (π = 1.36%; P = 0.01) and improved aneurysm occlusion (π = 6.18%) compared with high-porosity stents (π = 14.42%; P = 0.001) and low-porosity stents (π = 11.71%; P = 0.04). The prevalence of in-stent stenosis was lower for the intermediate-porosity (π = 0.57%) and high-porosity (π = 1.51%) stents than for the low-porosity stents (π = 3.30%; P < 0.05). PFT use had resulted in fewer poor clinical outcomes (π = 3.54%) compared with those without PFT use (π = 5.94%; P = 0.04). The DAPT duration had no effect on the outcomes.

CONCLUSIONS

In the present meta-analysis, which had selected for studies of cerebral aneurysm stenting that had reported the DAPT duration, intermediate-porosity stents and PFT use had resulted significantly improved outcomes. No effect of DAPT duration could be detected.

Results of Y-stent-assisted-coiling with a low-profile Neuroform Atlas stent in complex bifurcation aneurysms

Aim: Neuroform Atlas is a low-profile stent with an open-cell structure that can be deployed via a low-profile microcatheter. This study analyzed the safety, durability, and efficiency of Y-stent-assisted coiling (Y-SAC) with two Neuroform Atlas stents for treating unruptured wide-neck complex bifurcation aneurysms. Material and method: We retrospectively reviewed patients who were treated for intracranial bifurcation aneurysms using the Y-SAC technique with two Neuroform Atlas stents. A total of 94 consecutive patients were included in the study. Clinical and angiographic results and complications were evaluated before and after the procedure. Results: Y-SAC was successfully performed (100%) without any technical complications in any case. The mean angiographic follow-up period was 14.6±6.6 months. Follow-up DSA was performed on 93.6% of patients. The last follow-up angiograms demonstrated complete occlusion (RROC I) in 92%, and near-complete occlusion (RROC II) in 7% of the aneurysms. There was no mortality in this study. A procedure-related complication occurred in 4.2% of patients and caused permanent morbidity in 1% of patients. Conclusion: In the endovascular treatment of wide-neck complex bifurcation aneurysms, the Y-SAC method with two Neuroform Atlas stents is safe and effective with high aneurysm occlusion rates and a low risk of procedural complications.

Y-stent-assisted coiling with Neuroform Atlas stents for wide-necked intracranial bifurcation aneurysms: A preliminary report

Objective

To report our experience on Neuroform Atlas Y-stenting for coiling of unruptured wide-neck bifurcation aneurysms.

Methods

From March 2018 to January 2021, we treated 473 aneurysms in 436 patients with coil embolization, of which 15 cases with wide-necked bifurcation aneurysms were treated by Y-stent-assisted coiling with two Neuroform Atlas stents. We retrospectively reviewed the characteristics of patients and aneurysms, procedure-related complications, radiographic results, and clinical outcomes.

Results

All 15 cases using Neuroform Atlas Y-stenting were successful. Patients included 6 men and 9 women with a mean age ± standard deviation of 56.4±6.6 years. The mean dome and neck sizes were 6.4±3.1 mm and 4.7±1.8 mm, respectively. Immediate post-procedural angiograms showed complete occlusion in 46.7%, neck remnant in 13.3%, and incomplete occlusion in 40% of cases. No treatment-related morbidity or mortality occurred in any patients. All patients had good clinical outcomes (Glasgow Outcome Score 5) at both discharge and during a mean 12.3-month (range 1-28 months) follow-up. All aneurysms showed improved or stable occlusion on follow-up imaging. Further, the latest follow-up angiography showed complete occlusion in 73.3%, neck remnant in 6.7%, and incomplete occlusion in 20%.

Conclusions

Y-stent-assisted coiling with Neuroform Atlas stents might be a feasible and safe option for wide-necked bifurcation aneurysms.

Long-term Durability of Coil Embolization for Unruptured Aneurysm after Introduction of the Neck-bridge Stent: Comparison between the Pre-stent Era and the Stent Era

More complex aneurysms can be treated by coil embolization with neck-bridge stent assistance. However, concerns about postprocedural ischemic or hemorrhagic complications remain. In this study, we assessed the long-term durability after introduction of neck-bridge stent in the context of coil embolization for unruptured aneurysm by comparing re-treatment and neurological events between the pre-stent and stent eras. Unruptured aneurysms treated by coil embolization between April 2005 and May 2018 were analyzed retrospectively. We divided cases into two groups: the pre-stent era and the stent era. The cumulative rate of re-treatment and neurological events were assessed and compared. During the period, 177 aneurysms were treated in the pre-stent era and 354 aneurysms were treated in the stent era. The median follow-up was 55 months. In the stent era, the dome/neck (D/N) ratio was significantly lower (P <0.001) and the number of aneurysms located at the posterior circulation was higher (P <0.001). A stent was used in 31.92% of cases in the stent era. The cumulative rate of re-treatment was significantly higher in the pre-stent era than it was in the stent era in univariate and multivariate analyses (P = 0.008, P = 0.008, respectively). The cumulative rate of neurological events was not significantly different between the two groups. The re-treatment rate has been improved without increasing neurological complications after introduction of the neck-bridge stent.

Long-term outcomes of wide-necked intracranial bifurcation aneurysms treated with T-stent-assisted coiling

OBJECTIVE

The endovascular treatment of complex bifurcation aneurysms possessing a neck that incorporates multiple side branches remains a surgical challenge. Double-stent-assisted coiling techniques, such as those with stents in an X and Y configuration, enable the endovascular treatment of wide-necked complex intracranial bifurcation aneurysms. However, the intraluminal struts at the intersection point in X- and Y-stents are not amenable to endothelialization, which may lead to thromboembolic complications. Stenting in the T configuration is a relatively new double-stent coiling technique. T-stenting differs from X- or Y-stenting in that there are no overlapping or intersecting stent segments. Promising short-term results of T-stent-assisted coiling were recently reported. However, the long-term results have not yet been demonstrated. This retrospective study investigated the long-term angiographic and clinical results in patients with wide-necked complex intracranial bifurcation aneurysms treated with T-stent-assisted coiling.

METHODS

A retrospective review was performed to identify patients with wide-necked complex intracranial bifurcation aneurysms treated with T-stent-assisted coiling at 4 institutions. The technical success and the initial and follow-up clinical and angiographic outcomes were assessed. Aneurysm filling status was assessed according to the Raymond classification. Periprocedural and delayed complications were reviewed. The neurological status of the patients was evaluated using the modified Rankin Scale (mRS).

RESULTS

One hundred two aneurysms in 102 patients (54 females), whose mean age was 57.9 ± 13.0 years, were included in the study. T-stenting was performed successfully in all patients. Immediate postprocedural angiography revealed complete occlusion in 83.3% of patients. Periprocedural complications developed in 13.7%, resulting in permanent morbidity in 1.9% and death in 1%. Eighty patients (78.4%) had at least one follow-up DSA examination performed at 6 months or later following the endovascular procedure. The mean duration of angiographic follow-up was 30.0 ± 16.3 months. The last follow-up examinations showed complete occlusion in 90.0% of patients. During the follow-up period, only 1 patient (1.3%) required retreatment. Delayed thromboembolic complications were observed in 4 patients (3.9%) without permanent morbidity. The mRS scores of all patients at the last clinical follow-up were between 0 and 2.

CONCLUSIONS

The short-term angiographic findings showed that T-stent-assisted coiling is a feasible and effective endovascular method to treat wide-necked complex bifurcation aneurysms. The long-term angiographic follow-up results suggest that T-stent-assisted coiling provides a durable treatment for wide-necked complex bifurcation aneurysms with favorable clinical outcomes, demonstrating the long-term safety of T-stent-assisted coiling.

Safety and Efficacy of the Neuroform Atlas Stent for Treatment of Intracranial Aneurysms : A Systematic Review and Meta-Analysis

OBJECTIVE

The Neuroform Atlas (Stryker Neurovascular, Fremont, CA, USA) is a low-profile laser cut self-expanding nitinol stent designed to provide coil support and wall apposition during aneurysm embolisation. In this study, we performed a meta-analysis of outcomes after treatment with the Neuroform Atlas stent for the purpose of coil embolisation.

METHODS

The primary objectives of this meta-analysis were to define the safety (treatment-related complications, neurologic outcomes, mortality rate) and the efficacy (aneurysm occlusion rate) of the treatment of intracranial aneurysms with the Neuroform Atlas stent. A systematic review and meta-analysis was performed by searching PubMed, EMBASE, and the Cochrane CENTRAL Library for all published studies on the treatment of intracranial aneurysms with the Neuroform Atlas device up to 6 April 2020. The review was prepared in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 14 studies were analysed (577 patients with 593 intracranial aneurysms). The mean age was 58.2 years and 35.6% were male. Technical success of the procedure was 100%. RROC1/RROC2 (Raymond-Roy occlusion classification (RROC) 1/2) (total occlusion/neck remnant) at a mean follow-up of 8.9 months was achieved in 94.8%. RROC3 was 4.9%. All-cause mortality was 1.8% and permanent residual neurological deficit or disability was 2.7%. Overall complications at follow-up were 6.2%.

CONCLUSION

Our analysis demonstrated good rates of occlusion at follow-up for aneurysms treated with the Atlas device at follow-up. The safety profile appears similar to other low-profile intracranial stents.

Motion Correction of Dual Volume Reconstruction of Three‑dimensional Digital Subtraction Angiography for Follow‑up Evaluation of Intracranial Coiled Aneurysms

Purpose

To evaluate the usefulness of the "Motion Correction" function of the dual volume-3D-volume-rendering technique (DV-3D-VRT) in follow-up digital subtraction angiography (DSA) of intracranial coiled aneurysms.

Materials and Methods

This study used data collected from consecutive, follow-up DSAs after the coiling of 64 intracranial aneurysms in 59 patients. We performed subtracted 3D-rotational angiographies (3D-RAs) on all DSAs and obtained DV-3D-VRT images. We then assessed recurrence using DV-3D-VRT images with and without the motion correction functions (MC(+) vs. MC(-)) and observed which method showed better agreement with the reference assessment (using a combination of 2D DSA and TOF MRA images).

Results

The recurrence of MC(-) DV-3D-VRT images showed 51.6% (33/64) agreement with the reference assessment, whereas the MC(+) DV-3D-VRT images showed 78.1% (50/64) (P = 0.035, McNemar test).

Conclusion

Motion correction is a useful complementary imaging technique in evaluating aneurysm recurrence after endovascular embolization. MC(+) DV-3D-VRT image showed higher inter-observer agreement than MC(-) DV-3D-VRT.

Safety and efficacy of endovascular treatment of ruptured tiny cerebral aneurysms compared with ruptured larger aneurysms

PURPOSE

To investigate the effect and safety of endovascular embolization of tiny aneurysms (≤3 mm) within 72 h of subarachnoid hemorrhage compared with larger ones.

MATERIALS AND METHODS

Patients with intracranial aneurysms treated with endovascular embolization within 72 h were retrospectively enrolled and divided into group A (n = 33) with ruptured tiny aneurysms (≤3 mm) and group B (n = 244) with ruptured larger aneurysms (>3 mm). The clinical and angiographic data before and after embolization were analyzed.

RESULTS

Most tiny aneurysms were located at the posterior communicating artery (36.4%) followed by anterior communicating artery (18.2%). The stent-assisted coiling technique was used mostly in group A with 18 stents deployed (51.5%), but only 24 (9.8%) patients had stent-assisted coiling in group B, with the stent-assisted coiling technique more significantly (P < 0.001) frequently used in group A. No significant (P > 0.05) difference existed in the total, subtotal and incomplete occlusion of aneurysms in two groups. The procedure-related complication rate was not significantly (P > 0.05) different between groups A (24.2%) and B (17.0%). At discharge, no significant (P > 0.05) difference existed in the neurological abnormality between the two groups. Follow-up was performed in 64.5% (20/31) in group A and 75.6% (177/234) in group B. No significant (P > 0.05) difference existed in the aneurysm recurrence rate, deaths, and prognosis.

CONCLUSION

Early embolization of tiny cerebral aneurysms within 72 h of subarachnoid hemorrhage is safe and effective compared with ruptured large aneurysms treated in the same manner.

Y-Stent-Assisted Coiling With Low-Profile Neuroform Atlas Stents for Endovascular Treatment of Wide-Necked Complex Intracranial Bifurcation Aneurysms

BACKGROUND

Y-stent-assisted coiling is one of the eligible techniques for the treatment of complex bifurcation aneurysms. In majority of previous literature, Y-stenting has been performed using stents that could be delivered through large profile microcatheters that are often difficult to manipulate during navigation through sharply angled side branches. Attempts to navigate with these large profile catheters might cause serious complications during Y-stenting procedure.

OBJECTIVE

To investigate the safety, feasibility, and efficacy of Y-stent-assisted coiling procedure with Neuroform Atlas stents for the treatment of complex bifurcation aneurysms; Neuroform Atlas is a recently introduced open-cell stent that can be delivered though low-profile microcatheters.

METHODS

We identified the patients with intracranial bifurcation aneurysms treated by Y-stent-assisted coiling procedure with Neuroform Atlas stents. We assessed the immediate postoperative and follow-up clinical and angiographic outcomes. We also investigated the periprocedural and delayed complications.

RESULTS

A total of 30 aneurysms in 30 patients were included in the study. Y-stenting was successfully performed without any technical complications in all cases (100%). Immediate postprocedural angiography revealed total aneurysm occlusion in 83.3% of patients. The mean angiographic follow-up time was 11.8 mo. The last follow-ups showed complete occlusion in 93.3% of patients. There was no mortality in this study. A procedure-related complication developed in 6.7% and resulted in permanent morbidity in 3.3% of patients.

CONCLUSION

Neuroform Atlas stent combines the advantages of low-profile deployment microcatheters with an open-cell structure to achieve a successful Y-stenting procedure. Y-stent-assisted coiling with Neuroform Atlas stents provides a safe and effective endovascular treatment for wide-necked complex bifurcation aneurysms.

Safety and Long-term Efficacy of Stent-assisted Coiling for the Treatment of Complex Posterior Cerebral Artery Aneurysms

OBJECTIVE

To evaluate the safety and long-term efficacy of stent-assisted coiling for the treatment of complex posterior cerebral artery (PCA) aneurysms.

METHODS

Angiographic and clinical data of 23 patients harboring 23 complex PCA aneurysms treated with stent-assisted coiling from March 2010 to March 2017 were retrospectively reviewed.

RESULTS

In this study 8 (34.8%) aneurysms were located at the P1 segment, 7 (30.4%) at the junction of P1 and P2 segments (P1-2), and 8 (34.8%) at the P2 segment. The aneurysms were ruptured in 7 cases (30.4%). Thirteen were dissecting in nature, while the other 10 were classical saccular aneurysms. Of the patients, 5 (21.7%) had of history of recent head trauma, immediate angiographic results were Raymond class I in 5 (21.7%) cases, Raymond class II in 8 (34.8%), and Raymond class III in 10 (43.5%). Perioperative complications occurred in one case with occlusion of the PA due to acute in-stent thrombosis without any neurologic deficit at discharge. The last angiographic follow-up (mean 18.7 months) results demonstrated complete aneurysmal occlusion in 20 (87.0%) cases, PA occlusion in 1 (4.3%) and recurrence in 2 (8.7%). Of the two patients with aneurysm recurrence, one was treated by PA occlusion, and the other was treated with two overlapping stents. Clinical follow-up (mean 58.3 months) was available for all 23 patients, 22 (95.7%) patients had good neurologic outcomes (mRS score 0-2), and 1 (4.3%) patient died 7 months after the procedure for unknown reasons.

CONCLUSION

Stent-assisted coiling for the treatment of complex PCA aneurysms is safe and durable with a relatively low rate of complication and a relatively high rate of complete occlusion at long-term follow-up and is a promising alternative strategy for the reconstruction of the PCA.

Feasibility and midterm outcomes of endovascular embolization for true posterior communicating artery aneurysms

PURPOSE

Endovascular treatment (EVT) of true posterior communicating artery (PcomA) aneurysms has been rarely reported. This study reports the outcomes on a single-center cohort with true PcomA aneurysms who underwent EVT.

METHODS

Between June 2011 and June 2017, clinical data from 42 patients with 43 true PcomA aneurysms who underwent EVT were retrieved from a prospectively maintained single-center database. Endovascular techniques, perioperative complications, clinical outcomes, and angiographic results were retrospectively evaluated.

RESULTS

All aneurysms were treated successfully. Treatment modalities included simple coiling in 30 aneurysms, balloon-assisted coiling in two, and stent-assisted coiling in 11 cases. Immediate angiograms showed complete occlusion in 23 aneurysms (53.5%), residual neck in 8 cases (18.6%), and residual sac in 12 (27.9%). No procedure-related complications or mortality were observed. Of the 34 aneurysms that underwent angiographic follow-up at an average duration of 7.1 months post-procedure, complete occlusion was achieved in 22 (64.7%), neck remnant in eight (23.5%), and residual sac in four (11.8%) aneurysms, respectively. Six aneurysms (18.2%) that underwent conventional coiling developed recanalization and required retreatment. Seven cases that received stent-assisted coiling did not develop recurrence. Clinical follow-up (mean, 24.3 months) of all patients demonstrated no neurologic deterioration or (re)bleeding.

CONCLUSION

EVT of the true PcomA aneurysm is a safe and feasible procedure but may be associated with recurrence in midterm follow-up, requiring close surveillance and potential retreatment.

Double stent assisted coiling of intracranial bifurcation aneurysms in Y and X configurations with the Neuroform ATLAS stent: immediate and mid term angiographic and clinical follow-up

Purpose

Self-expandable stents have broadened the spectrum of endovascular treatment of intracranial aneurysms. However, procedures involving double stenting in Y/X configurations carry a relatively high risk of procedural complications. The Neuroform ATLAS, the evolution of Neuroform EZ, is a nitinol self-expanding hybrid/open cell stent which can be delivered through a low profile 0.017 inch catheter. We present our experience in the treatment of intracranial aneurysms with this stent in Y and X configurations.

Materials and methods

We prospectively maintained a database from consecutive patients who underwent double stent assisted coiling with the Neuroform ATLAS, from July 2015 to February 2019. Clinical and angiographic results were analyzed.

Results

55 patients harboring 55 bifurcation aneurysms were treated with double stenting: 52 ‘Y’ configurations, 3 ‘X’ configurations. Deployment was successful in all cases. Post-treatment control angiography showed complete occlusion in 33 cases (60%), neck remnant in 8 cases (14.5%), and incomplete occlusion in 14 cases (25.4%). The overall symptomatic periprocedural complication rate was 12.7%. 38 aneurysms underwent follow-up (69%, mean duration 16 months): 33 aneurysms (87%) were completely occluded, 3 aneurysms (8%) had a neck remnant, and 2 aneurysms (5%) were incompletely occluded.

Conclusion

The Neuroform ATLAS is an effective device for treatment of bifurcation aneurysms, allowing good conformability, a high level of navigability, and easy mesh crossing to perform Y/X stenting procedures. The rate of procedural complications remains non-negligible, and an indication for a double stenting procedure should be carefully discussed in a multidisciplinary meeting.

MRA versus DSA for the follow-up imaging of intracranial aneurysms treated using endovascular techniques: a meta-analysis

BACKGROUND

Treated aneurysms must be followed over time to ensure durable occlusion, as more than 20% of endovascularly treated aneurysms recur. While digital subtraction angiography (DSA) remains the gold standard, magnetic resonance angiography (MRA) is attractive as a non-invasive follow-up technique. Two different MRA techniques have traditionally been used: time-of-flight (TOF) and contrast-enhanced (CE) MRA. We analysed data from studies comparing MRA techniques with DSA for the follow-up of aneurysms undergoing endovascular treatment. Subgroup analysis of stent-assisted coiling (SAC) and flow diversion (FD) techniques was completed.

METHODS

Comprehensive searches using the Embase, PubMed, and Cochrane databases were performed and updated to November 2018. Pooled sensitivity and specificity were calculated using aneurysm occlusion status as defined by the Raymond-Roy occlusion grading scale.

RESULTS

The literature search yielded 1579 unique titles. Forty-three studies were included. For TOF-MRA, sensitivity and specificity of all aneurysms undergoing endovascular therapy were 88% and 94%, respectively. For CE-MRA, the sensitivity and specificity were 88% and 96%, respectively. For SAC and FD techniques, sensitivity and specificity of TOF-MRA were 86% and 95%, respectively. CE-MRA had sensitivity and specificity of 90% and 92%.

CONCLUSION

MRA is a reliable modality for the follow-up of aneurysms treated using endovascular techniques. While the data are limited, MRA techniques can also be used to reliably follow patients undergoing FD and SAC. However, clinical factors must be used to optimize follow-up regimens for individual patients.

Angiographic and clinical results of anterior communicating artery aneurysm endovascular treatment

Introduction

The anterior communicating artery (ACoA) is the most common location of intracranial aneurysms, observed in 35% of cases. Endovascular treatment has become an alternative to surgical clipping and the primary method of choice.

Aim

To assess the treatment results of ruptured and unruptured ACoA aneurysms and to assess the incidence of intraprocedural complications and various factors influencing these aspects.

Material and methods

One hundred and eleven embolizations of ACoA aneurysms (80.7% ruptured and 19.3% unruptured) were retrospectively analysed. The methods of embolization were: coiling, balloon-assisted coiling, stent-assisted coiling. Morphology and dimensions of aneurysms were assessed on 3D digital subtraction angiography (DSA) images. Medical records were analysed for patient’s clinical status at admission, intraprocedural complications, follow-up examination and modified Rankin Scale (mRS) score 1 month after discharge.

Results

Immediately after the procedure 56.9% of patients had Raymond-Roy Occlusion Classification (RROC) class I, 37.6% class II and 5.5% class III. The overall intraprocedural complication rate was 6.6%. There were significantly more cases of bleeding (p = 0.012) and coil prolapse (p = 0.012) during the procedures ending with higher packing density. Twenty-eight (25.7%) patients died during hospital stay, 27 (96.4%) with ruptured aneurysm. In the follow-up of 41 patients, RROC was the same or improved in 73.2% of cases and recanalization occurred in 26.8%. Six patients with aneurysm recanalization underwent repeat embolization.

Conclusions

Endovascular embolization of ACoA aneurysms is an effective and safe treatment method. The most powerful factor influencing the incidence of complications is packing density. Superior orientation of the dome, initial incomplete embolization and poor outcome in mRS scale are factors predisposing to ACoA aneurysm recurrence.

Initial and Long-Term Outcomes of Complex Bifurcation Aneurysms Treated by Y-Stent-Assisted Coiling with Low-Profile Braided Stents

BACKGROUND AND PURPOSE

Coiling complex intracranial bifurcation aneurysms often necessitates the implantation of double stents in various configurations, such as Y-stent placement. Low-profile braided stents have been introduced recently to facilitate the endovascular treatment of wide-neck aneurysms. We aimed to investigate the feasibility, safety, efficacy, and durability of Y-stent-assisted coiling with double low-profile braided stents for the treatment of complex bifurcation aneurysms.

MATERIALS AND METHODS

A retrospective review was performed to identify patients who were treated using Y-stent-assisted coiling with low-profile braided stents. Technical success was assessed, as were initial and follow-up clinical and angiographic outcomes. Periprocedural and delayed complications were reviewed. Preprocedural and follow-up clinical statuses were assessed using the modified Rankin Scale.

RESULTS

Forty patients with 40 intracranial aneurysms were included in the study. Y-stent placement was successfully performed in all cases. Immediate postprocedural digital subtraction angiography images revealed total aneurysm occlusion in 72.5% of cases. The mean angiographic follow-up time was 24.8 months. The last follow-up angiograms showed complete occlusion in 85% of patients. During follow-up, only 1 patient showed an increase in the filling status of the aneurysm and that patient did not require retreatment. There was no mortality in this study. The overall procedure-related complication rate, including asymptomatic complications, was 17.5%. A permanent morbidity developed in 1 patient (2.5%).

CONCLUSIONS

The long-term angiographic and clinical outcomes of this retrospective study demonstrate that Y-stent-assisted coiling using low-profile braided stents is an effective, relatively safe, and durable endovascular treatment for wide-neck and complex bifurcation aneurysms.

Stent-assisted coiling of intracranial aneurysms using LEO stents: long-term follow-up in 153 patients

PURPOSE

Coiling associated with placement of a self-expandable intracranial stent has improved the treatment of intracranial wide-necked aneurysms. Little is known, however, about the durability of this treatment. The purpose of this report is to present our experience with the LEO stent and to evaluate the complications, effectiveness, and long-term results of this technique.

METHODS

We analyzed the records of 155 intracranial unruptured aneurysms that were treated by stent-assisted coiling with a LEO stent between 2008 and 2012. Procedural, early post-procedural, and delayed complications were recorded. Clinical and angiographic follow-up of patients was conducted over a period of at least 36 months.

RESULTS

No procedural mortality was observed. One-month morbidity was observed in 14 out of 153 patients (9,15%). One hundred thirty-eight patients (with 140 aneurysms) had clinical and angiographic follow-up for more than 36 months. No aneurysm rupture was observed during follow-up. Four patients presented an intra-stent stenosis at 8 months, and 6 patients who had an early recurrence were retreated. Final results showed 85% complete occlusion, 13% neck remnants, and 2% stable incomplete occlusion.

CONCLUSION

Stent-assisted coiling with the LEO stent is a safe and effective treatment for unruptured intracranial aneurysms. The long-term clinical outcomes with the LEO stent are excellent with a high rate of complete occlusion that is stable over time.

Long-term follow-up of aneurysms treated electively with woven stent-assisted coiling

Background

Preliminary short-term results for stent-assisted coil embolization (SACE) using woven/braided stents have been promising. However, evidence supporting mid- to long-term efficacy and durability is lacking.

Objective

To report the long-term results for the durability of elective intracranial aneurysms treated with woven stents.

Materials and methods

Between May 2012 and May 2015, 98 consecutive patients with 103 aneurysms underwent elective woven SACE across three Australian neurovascular centres. All patients had immediate, 6- and 18-month clinical and radiological follow-up. Radiological assessment was performed with modified Raymond–Roy occlusion scores based on angiography results, while clinical assessment was based on the modified Rankin Scale.

Results

Six-month follow-up was available in 100 aneurysms, and an 18-month follow-up in 97 aneurysms. Total occlusion rates of 82% were achieved at inception, 82% at 6 months, and 90% at 18 months. Satisfactory occlusion with small neck remnants was present in 17% at inception, 16% at 6 months, and 9% at 18 months. Good neurological outcomes were achieved in 95% at 18 months. Intraprocedural thromboembolic events were recorded in 3% and delayed events in 1% (all in patients taking clopidogrel). Aneurysm recurrence occurred in one patient (1%). Technical complications occurred in 5%. The total complication rate was 10%.

Conclusions

Woven SACE is safe, efficacious, and durable at long-term 18-month follow-up, with very low recurrence and re-treatment rates. Preliminary results appear better than those for traditional laser-cut stents.

Midterm results of T-stent–assisted coiling of wide-necked and complex intracranial bifurcation aneurysms using low-profile stents

OBJECTIVE

Coiling of wide-necked and complex bifurcation aneurysms frequently requires implantation of double stents in various configurations. T-stent–assisted coiling involves the nonoverlapping implantation of 2 stents to protect the daughter vessels of bifurcation and is followed by coiling of the aneurysm. The authors studied the feasibility, efficacy, and safety of the T-stent–assisted coiling procedure as well as the midterm angiographic/clinical outcomes of patients with wide-necked bifurcation intracranial aneurysms treated using this technique.

METHODS

The authors retrospectively identified patients with wide-necked bifurcation intracranial aneurysms treated using double-stent–assisted coiling with a T-stent configuration.

RESULTS

Twenty-four patients with 24 aneurysms and a mean of age of 51.91 years were identified. The most common locations were the middle cerebral bifurcation (45.8%) and anterior communicating artery (35.7%). T stentings were performed using low-profile stents. The procedures were performed with a technical success rate of 95.8%, and an immediate total occlusion rate of 79.2% was achieved. We observed periprocedural complications in 16.7% of cases and a delayed thromboembolic event in 4.2%. The complications caused permanent morbidity in 1 patient (4.2%). No deaths occurred. The mean angiographic follow-up duration was 9.3 months. The total occlusion rate at the last follow-up was 81.2%. The recanalization rate was 4.5%. Modified Rankin Scale scores of all patients at the last follow-ups were between zero and 2.

CONCLUSIONS

T-stent–assisted coiling using low-profile stents is a feasible, effective, and relatively safe endovascular technique used to treat wide-necked and complex intracranial aneurysms. The midterm angiographic and clinical outcomes are outstanding.

Subarachnoid hemorrhage after surgical treatment of unruptured intracranial aneurysms

OBJECTIVE Only a few previous studies have investigated subarachnoid hemorrhage (SAH) after surgical treatment in patients with unruptured intracranial aneurysms (UIAs). Given the improvement in long-term outcomes of embolization, more extensive data are needed concerning the true rupture rates after microsurgery in order to provide reliable information for treatment decisions. The purpose of this study was to investigate the incidence of and risk factors for postoperative SAH in patients with surgically treated UIAs. METHODS Data from 702 consecutive patients harboring 852 surgically treated UIAs were evaluated. Surgical treatments included neck clipping (complete or incomplete), coating/wrapping, trapping, proximal occlusion, and bypass surgery. Clippable UIAs were defined as UIAs treated by complete neck clipping. The annual incidence of postoperative SAH and risk factors for SAH were studied using Kaplan-Meier survival analysis and Cox proportional hazards regression models. RESULTS The patients' median age was 64 years (interquartile range [IQR] 56-71 years). Of 852 UIAs, 767 were clippable and 85 were not. The mean duration of follow-up was 731 days (SD 380 days). During 1708 aneurysm years, there were 4 episodes of SAH, giving an overall average annual incidence rate of 0.23% (95% CI 0.12%-0.59%) and an average annual incidence rate of 0.065% (95% CI 0.0017%-0.37%) for clippable UIAs (1 episode of SAH, 1552 aneurysm-years). Basilar artery location (adjusted hazard ratio [HR] 23, 95% CI 2.0-255, p = 0.0012) and unclippable UIA status (adjusted HR 15, 95% CI 1.1-215, p = 0.046) were significantly related to postoperative SAH. An excellent outcome (modified Rankin Scale score of 0 or 1) was achieved in 816 (95.7%) of 852 cases overall and in 748 (98%) of 767 clippable UIAs at 12 months. CONCLUSIONS In this large case series, microsurgical treatment of UIAs was found to be safe and effective. Aneurysm location and unclippable morphologies were related to postoperative SAH in patients with surgically treated UIAs.

A Single Center Experience with Coil Embolization for Cerebral Aneurysms Greater than 10 mm in the Internal Carotid Artery

We investigated endovascular treatment for 10 mm or larger aneurysms in the internal carotid artery (IC), including the cavernous portion, the paraclinoid portion, and the posterior communication artery (PC). Between 2011 and 2014 at our hospital, there were 35 cases of aneurysms that were 10 mm or larger in the carotid artery. We analyzed these 35 cases retrospectively based on the size and location of the aneurysms, method of treatment, number of coils implanted, use of a stent, complications, rupture after treatment, ophthalmologic symptoms, and need for re-treatment. There was no bleeding after treatment. Of the 35 cases, four cases (11%) had permanent complications. Re-treatment was indicated in 11 cases (31%), including eight cases localized in the paraclinoid portion, two cases in the IC-PC, and one case in the cavernous portion. Among these re-treatment cases, two cases required a third treatment. Of the 16 cases with paraclinoid aneurysms, half required re-treatment. Of the 12 cases with ophthalmologic symptoms prior to treatment, 9 (75%) improved or had no change and 3 (25%) became worse. There were no complications in the 13 re-treatment procedures. Re-treatment is not uncommon, and a scheduled follow-up is needed. Coil embolization has been one of the main options for aneurysms that are 10 mm or larger in the IC. In the future, these large aneurysms will be treated with a flow diverter stent (FD).

Stent-Assisted Coiling of Wide-Neck Intracranial Aneurysms Using Low-Profile LEO Baby Stents: Initial and Midterm Results

BACKGROUND AND PURPOSE

Low-profile self-expandable stents were recently introduced for the treatment of wide-neck intracranial aneurysms. This study investigated the initial and midterm clinical and angiographic results of LEO Baby stent-assisted coiling in the treatment of wide-neck intracranial aneurysms.

MATERIALS AND METHODS

A retrospective review was performed to identify patients who were treated with LEO Baby stent-assisted coiling. Eighty patients with 80 wide-neck intracranial aneurysms were included in the study. Eleven patients (13.8%) presented with subarachnoid hemorrhage. All patients were treated with LEO Baby stent-assisted coiling. Technical success and immediate postprocedural clinical and angiographic outcomes were evaluated. Seventy-three patients attended angiographic and clinical follow-up for a mean duration of 7.2 ± 3.8 months. Periprocedural and delayed complications were reviewed. Preprocedural and follow-up clinical statuses were assessed by using the modified Rankin Scale.

RESULTS

The technical success rate of the procedure was 97.5%. The immediate postprocedural angiography revealed a complete occlusion of the aneurysm in 75% of the 80 patients. The last follow-up angiograms showed complete occlusion in 85.7% of the 77 patients with an angiographic follow-up. Of the 77 patients with a follow-up angiography, 6.5% showed an increase in the filling status of the aneurysm and 5.2% required retreatment. The overall procedure-related complication rate, including asymptomatic complications, was 11.3%. The permanent morbidity rate was 3.8%. There was no mortality in this study.

CONCLUSIONS

This case series demonstrates the relative safety, efficacy, and midterm durability of the LEO Baby stent-assisted coiling procedure for the treatment of wide-neck intracranial aneurysms.

Complications in Stent-Assisted Endovascular Therapy of Ruptured Intracranial Aneurysms and Relevance to Antiplatelet Administration: A Systematic Review

BACKGROUND AND PURPOSE

Despite the increasing use of stent-assisted coiling for ruptured intracranial aneurysms, there is little consensus regarding the appropriate antiplatelet administration for this. The objectives of this systematic review were to provide an overview of complications and their association with the method of antiplatelet administration in stent-assisted coiling for ruptured intracranial aneurysms.

MATERIALS AND METHODS

A comprehensive search of the literature in the data bases was conducted to identify studies reporting complications of stent-assisted coiling for ruptured intracranial aneurysms. The pooled event rate of preprocedural thromboembolisms, hemorrhages, and mortality was estimated from the selected studies. Subgroup analyses were performed by the method of antiplatelet administration (pre-, postprocedural, and modified). Meta-analysis was conducted to compare periprocedural complications and mortality between ruptured intracranial aneurysms and unruptured intracranial aneurysms.

RESULTS

Of the 8476 studies identified, 33 with 1090 patients were included. The event rates of thromboembolism and intra- and postprocedural hemorrhage were 11.2% (95% CI, 9.2%-13.6%), 5.4% (95% CI, 4.1%-7.2%), and 3.6% (95% CI, 2.6%-5.1%), respectively. Subgroup analyses of thromboembolism showed a statistically significant difference between groups (P < .05). In the preprocedural and modified antiplatelet groups, the risk for thromboembolism in stent-assisted coiling for ruptured intracranial aneurysm was not significantly different from that for unruptured intracranial aneurysm, though this risk of the postprocedural antiplatelet group was significantly higher in ruptured intracranial aneurysms than in unruptured intracranial aneurysms.

CONCLUSIONS

On the basis of current evidence, complications of stent-assisted coiling for ruptured intracranial aneurysm may be affected by the method of antiplatelet administration.

Predictors of success following endovascular retreatment of intracranial aneurysms

INTRODUCTION

Although approximately one in every 10 patients undergoing coil embolization of intracranial aneurysms requires retreatment, the factors that are associated with outcome following retreatment remain to be fully elucidated.

METHODS

This is a single-center, retrospective review of 43 patients with 58 intracranial aneurysms that were retreated from 2004 to 2014. Aneurysms undergoing first time or microsurgical retreatment were excluded. Retreatment types were grouped into those without permanent parent vessel support (stand-alone and balloon-assisted coiling) versus those with permanent parent vessel support (stent-assisted coiling, stand-alone stenting, and flow diversion). The Modified Raymond Roy Classification was used to group aneurysms at all angiographic follow-up points either in the successful outcome group (Class I or II) or the unsuccessful outcome group (Class IIIa or IIIb).

RESULTS

Of aneurysms with follow-up, 50% were in the successful group and 50% in the unsuccessful group. In univariate analysis, small aneurysm size (p < 0.001), previous treatment type (p = 0.022), retreatment type (p = 0.001), and initial occlusion class (p = 0.005) were all associated with angiographic outcome. In multivariate analysis, small aneurysm size (p = 0.005, odds ratio (OR) 24.56, confidence interval (CI) 2.68-225.4) and retreatment type with permanent parent vessel support, namely stent-assisted coiling (p = 0.017, OR 31.1, CI 1.89-517.7), were associated with retreatment success.

CONCLUSIONS

Small aneurysm size and retreatment with permanent parent vessel support, namely stent-assisted coiling, are predictors of success following endovascular retreatment of intracranial aneurysms. These findings could be useful in the effort to both prevent and predict treatment failure following endovascular retreatment.

Bilateral Cavernous Carotid Aneurysms: The Growth Potential of a Contralateral Aneurysm after Therapeutic Unilateral Internal Carotid Artery Occlusion

BACKGROUND

Although the introduction of flow-diverter stents has been recognized as a major revolution in the treatment of cavernous carotid aneurysms (CCAs), therapeutic internal carotid artery occlusion (TICAO) remains a reliable procedure for alleviating symptoms caused by CCAs. However, TICAO has the potential risk of the enlargement of coexisting aneurysms that are frequently detected in CCA patients. The purpose of this study is to assess the occurrence of the enlargement of aneurysms coexisting with CCAs after TICAO.

METHODS

We reviewed medical charts of CCA patients who were managed using unilateral TICAO. Coexisting aneurysms were identified using angiograms obtained before TICAO, and imaging data in long follow-up periods were retrospectively examined to determine the extent of the enlargement after TICAO.

RESULTS

Of 12 patients with CCAs, 10 had 12 coexisting aneurysms; 5 of the coexisting aneurysms (41.7%) showed enlargement during a mean follow-up period of 8.1 years, and all enlarged aneurysms were smaller of the bilateral CCAs; the larger CCA had been managed by TICAO. Five of 6 (83.3%) patients with bilateral CCAs showed enlargement of the contralateral aneurysm after TICAO. Two contralateral CCAs showed marked enlargement after TICAO and were subsequently treated with stent-assisted coil embolization.

CONCLUSIONS

Contralateral, smaller aneurysms frequently enlarge after unilateral TICAO in patients with bilateral CCAs. The findings emphasize the importance of long-term observation after TICAO and appropriate interventions against enlarging contralateral aneurysms.

Long-term angiographic outcome of stent-assisted coiling compared to non-assisted coiling of intracranial saccular aneurysms

AIM

To compare angiographic result at long-term follow-up, and rates of progressive occlusion, recurrence, and retreatment of stent-assisted coiled (SAC) and non-assisted coiled (NAC) intracranial saccular aneurysms.

METHODS

Retrospective evaluation of department records identified 260 patients with 283 saccular intracranial aneurysms who had long-term angiographic follow-up (more than 12 months) and were successfully treated with SAC (89 aneurysms) or NAC (194 aneurysms) at the University Hospital Center Zagreb from June 2005 to July 2012. Initial and control angiographic results in both groups were graded using Roy/Raymond scale, converted to descriptive terms, and the differences between them were evaluated for statistical significance. A multivariate analysis was performed to identify factors related to progression of aneurysm occlusion and recurrence at follow-up, and those related to aneurysm retreatment.

RESULTS

There were more progressively occluded aneurysms in SAC group (38 of 89 aneurysms, 42.7%) than in NAC group (46 of 194, 23.7%) (P=0.002), but there were no significant differences in the rates of recanalization, regrowth, and stable result. Multivariate logistic regression identified the use of stent as the most important factor associated with progressive occlusion (P=0.015, odds ratio 2.22, 95% confidence interval 1.17-4.21), and large aneurysm size and posterior circulation location as most predictive of aneurysm recurrence and retreatment.

CONCLUSION

The use of stent is associated with delayed occlusion of initially incompletely coiled aneurysms during follow-up, but does not reduce the rate of recurrence and retreatment compared to coiling alone. Long-term angiographic follow-up is needed for both SAC and NAC aneurysms.

Double-clip technique for the microneurosurgical management of very small (< 3 mm) intracranial aneurysms

BACKGROUND

The treatment of very small (≤ 3 mm) aneurysms is technically challenging. Mini-clips used for clipping these small aneurysms have a smaller closing force compared with standard clips.

OBJECTIVE

To describe the double-clip technique for very small aneurysms.

METHODS

The double-clip technique, a parallel duplication clipping technique of booster clipping, is used by the senior author for clipping very small aneurysms with morphology suitable for the application of 2 clips. The aneurysm is clipped after application of temporary clip(s), administration of adenosine, or both. An initial mini-clip is applied, leaving a small residual neck sufficient for application of the second mini-clip. A second mini-clip of the same size and shape is applied on the residual neck parallel to the initial clip. The initially applied mini-clip, which is in close contact with the second clip, supports the second clip and prevents its slippage. This technique was retrospectively reviewed over a 13-year period (1997-2009). There were 3246 patients with 4757 aneurysms treated in the same period.

RESULTS

The outcomes of 39 patients with 40 very small aneurysms clipped with the double-clip technique were analyzed. None of the patients had technique-related complications. Postoperative angiograms revealed complete aneurysm occlusion of 39 aneurysms and a small residual neck in 1 aneurysm. No parent artery obstruction was observed in the postoperative angiogram.

CONCLUSION

The double-clip technique is a safe and effective variation of booster clipping in the treatment of very small aneurysms with suitable morphology.