Added Value of Selective Intra-arterial Cone-Beam CT Angiography in the Management of Visceral Artery Aneurysms

PURPOSE

The aim of this study is to evaluate the value of selective intra-arterial cone-beam computed tomography angiography (CBCTA) relative to conventional computed tomography angiography (CTA) in understanding visceral artery aneurysm (VAA) morphology, and its impact on treatment planning.

MATERIALS AND METHODS

Between January 2017 and August 2021, all patients who had a diagnosis of VAA and underwent intraoperative CBCTA imaging were retrospectively reviewed. Impact on treatment decisions, optimal C-arm angulations derived from CBCTA, and additional radiation exposure were reported. Two blinded independent reviewers qualitatively reviewed CBCTA and conventional CTA images. A 5-point Likert scale (1=poor image quality, 5=excellent image quality) was used to assess the overall image quality of each modality. Number of vessels arising from the aneurysm sac was counted.

RESULTS

A total of 16 patients had a diagnosis of VAA during the study period, of whom 10 patients had intraoperative CBCTA and conventional CTA available for review. Out of 10 patients, 7 underwent successful endovascular treatment, 2 were deemed not amenable for endovascular embolization based on intraoperative CBCTA findings, and 1 had resolved pseudoaneurysm. Total fluoroscopy time and radiation dose (dose area product [DAP] and skin dose) for all procedures were 27.7 ± 19.9 minutes, 28 362 (±18 651) µGy*m2, and 1879 (±1734) mGy, respectively. Radiation exposure from CBCTA (DAP and skin dose) was 5703 (±3967) µGy*m2 and 223.6 (±141.3) mGy, respectively. In patients who underwent endovascular treatment, the proportional DAP from CBCTA was 18.3% (±15.3%) of the total procedural radiation dose. Qualitative rating of overall image quality of CBCTA images was superior to CTA images (mean score: 4.55 vs 3, p<0.001). More branch vessels arising from the VAA were identified by all reviewers in CBCTA as compared with conventional CTA (median, min-max: 3, 0-4 vs 2,1-3 vessels).

CONCLUSION

Intraoperative CBCTA after selective intra-arterial contrast injection, with better spatial resolution, provided better delineation of visceral aneurysm morphology as compared with conventional, intravenous CTA and enabled optimal treatment planning at a reasonable additional radiation exposure.

CLINICAL IMPACT

Visceral artery aneurysms (VAA) are often diagnosed incidentally by conventional computed tomographic angiography (CTA). Endovascular treatment typically requires selective angiographies at multiple projections to better understand aneurysm morphology, location, and efferent branch vessels. Intra-arterial cone-beam CT angiography (CBCTA) for VAA has the advantage of selective contrast opacification, better spatial resolution, and three-dimensional/multi-planar visualization of aneurysm morphology. In addition, CBCTA enables identification of optimal C-arm working projection for subsequent endovascular treatment. The aim of this study is to evaluate the value of intraoperative CBCTA relative to conventional CTA in understanding visceral artery aneurysm morphology and its impact on treatment planning.

Duration of dual-antiplatelet therapy after stent-assisted coil for unruptured intracranial aneurysm: A nationwide cohort study

BACKGROUND

Stent-assisted coil (SAC) is increasingly used to treat unruptured intracranial aneurysm (UIA). However, the optimal duration of dual-antiplatelet therapy (DAPT) after SAC insertion remains unknown.

AIM

To assess the time-dependent effect of DAPT on the risk of ischemic and hemorrhagic complications after SAC.

METHODS

This is a retrospective cohort study among patients with UIA treated with SAC using the nationwide health claims database in South Korea between 2009 and 2020. Multivariate Cox regression analysis was used, which included the use of DAPT as a time-dependent variable. The effect of DAPT was investigated for each period of "within 90 days," "91 to 180 days," "181 to 365 days," and "366 to 730 days" after SAC. The primary outcome was a composite of ischemic stroke and major bleeding in each period within two years after SAC.

RESULTS

Of the 15,918 patients, mean age at SAC was 57.6 ± 10.8 years, and 3815 (24.0%) were men. The proportion of patients on DAPT was 79.4% at 90 days, 58.3% at 180 days, and 28.9% at 1 year after SAC. During the 2 years after SAC, the primary composite outcome occurred in 356 patients (2.2%). DAPT significantly reduced the primary composite outcome within 90 days after SAC (adjusted hazard ratio (aHR), 0.44; 95% confidence interval (CI), 0.28-0.69; p < 0.001); however, this was not the case after 90 days (all p > 0.05). DAPT reduced ischemic stroke risk within 90 days (aHR, 0.31; 95% CI 0.18-0.54; p < 0.001), and 91 to 180 days after SAC (aHR 0.40; 95% CI 0.18-0.88; p = 0.022); however, after 180 days, DAPT was no longer beneficial.

CONCLUSIONS

In patients with UIA treated with SAC, 3 months of DAPT was associated with a decreased risk of the composite of ischemic and hemorrhagic complications.

Classification and hemodynamic characteristics of delayed intracerebral hemorrhage following stent-assisted coil embolism in unruptured intracranial aneurysms

Background and objective

Stent-assisted coil (SAC) embolization is a commonly used endovascular treatment for unruptured intracranial aneurysms (UIAs) but can be associated with symptomatic delayed intracerebral hemorrhage (DICH). Our study aimed to investigate the hemodynamic risk factors contributing to DICH following SAC embolization and to establish a classification for DICH predicated on hemodynamic profiles.

Methods

This retrospective study included patients with UIAs located in the internal carotid artery (ICA) treated with SAC embolization at our institution from January 2021 to January 2022. We focused on eight patients who developed postoperative DICH and matched them with sixteen control patients without DICH. Using computational fluid dynamics, we evaluated the hemodynamic changes in distal arteries [terminal ICA, the anterior cerebral artery (ACA), and middle cerebral artery (MCA)] pre-and post-embolization. We distinguished DICH-related arteries from unrelated ones (ACA or MCA) and compared their hemodynamic alterations. An imbalance index, quantifying the differential in flow velocity changes between ACA and MCA post-embolization, was employed to gauge the flow distribution in distal arteries was used to assess distal arterial flow distribution.

Results

We identified two types of DICH based on postoperative flow alterations. In type 1, there was a significant lower in the mean velocity increase rate of the DICH-related artery compared to the unrelated artery (-47.25 ± 3.88% vs. 42.85 ± 3.03%; p < 0.001), whereas, in type 2, there was a notable higher (110.58 ± 9.42% vs. 17.60 ± 4.69%; p < 0.001). Both DICH types demonstrated a higher imbalance index than the control group, suggesting an association between altered distal arterial blood flow distribution and DICH occurrence.

Conclusion

DICH in SAC-treated UIAs can manifest as either a lower (type 1) or higher (type 2) in the rate of velocity in DICH-related arteries. An imbalance in distal arterial blood flow distribution appears to be a significant factor in DICH development.

Stent-Assisted Coil Embolization of Ruptured Aneurysms in the Acute Stage: Advantages and Disadvantages

Objective

In the acute stage of ruptured cerebral aneurysms, limited devices are available, making the treatment difficult. We aimed to evaluate the outcomes of the coil embolization with stenting for the ruptured cerebral aneurysms in the acute stage.

Methods

We assessed 22 cases treated with stenting among 134 of 169 consecutive patients with subarachnoid hemorrhages undergoing an endovascular treatment between April 2014 and December 2021, of which 134 underwent an embolization during the acute stage. A stent was used in the patients wherein the treatment with the balloon-assisted or double catheter technique was difficult. Stenting was performed under the loading of two or more antiplatelet agents.

Results

The mean age of the patients was 68.9 years, of which five were male and 14 (63.6%) had severe grade (World Federation of Neurosurgeons grade IV, V). The aneurysm site was the anterior communicating artery in four cases, internal carotid artery in nine, middle cerebral artery in two, vertebrobasilar artery in six, and posterior cerebral artery in one. The aneurysm shape was saccular in 13 cases, dissection in seven, and fusiform in two. Stents were used for wide-neck aneurysms in 12 cases, vascular preservation in seven, and rescue in three. The mean maximum diameter was 9.6 mm. The mean neck size was 6.4 mm. Complete occlusion and neck remnant were found in eight and seven cases, respectively. The perioperative complication rate was 45.5% (thromboembolism in five cases, stent occlusion in two, re-bleeding in two, and cerebral hemorrhage in one). The outcomes included modified Rankin Scale 0-2 in seven cases, 4-5 in five, and 6 in nine. Stent-related death occurred in one case. The rate of morbidity and mortality was 18.2%. Although stents were used in the acute stage of rupture, they were used for the right reasons. However, a high rate of complications occurred: two cases of re-bleeding, in which an incomplete occlusion was a factor.

Conclusion

Stent placement in patients with the acute ruptured cerebral aneurysms should be carefully determined and efforts should be made to reduce the embolic and hemorrhagic complications. However, it may be an effective treatment option when other options could be extremely difficult.

Three-dimensional reconstruction imaging by C-arm computed tomography accurately visualizes in-stent neointimal formation in patients with stent-assisted coil embolization

Background

Stent apposition to the vessel wall and in-stent neointimal formation after stent-assisted coil embolization for intracranial aneurysm are important factors associated with postoperative thromboembolic complications. No assessment methods have been established to depict 3-dimensional (3D) all-round in-stent neointimal formation.

Objective

To demonstrate the superiority of Dyna-3D imaging assessment as a modality for all-round ISNF in comparison with conventional two-dimensional digital subtraction angiography (2D-DSA).

Methods

Consecutive patients who underwent braided stent-assisted coil embolization for unruptured aneurysm between November 2016 and September 2021 were enrolled. Radiological assessments for stent apposition to the parent vessel after stent deployment and in-stent neointimal formation after 3 months were obtained. Dyna-3D was reconstructed by overlapping a plain image showing stent struts with a rotational DSA image showing the vessel lumen. Reconstructed Dyna-3D images can be rotated to any angle on the screen to evaluate to stent apposition around the vessel and in-stent neointimal formation in 3D, for comparison with 2D-DSA evaluations.

Results

Among the 73 patients enrolled, 70 patients (96%) showed complete stent wall apposition on Dyna-3D. Higher intra-rater agreement was confirmed on assessment of in-stent neointimal formation with Dyna-3D (Cohen's κ = 0.811) than with conventional 2D-DSA (Cohen's κ = 0.517). in-stent neointimal formation could not be confirmed on conventional imaging in 9 cases (16%) and on Dyna-3D in 2 cases (3%). The number of in-stent neointimal formations rated as stent wire completely outside the endothelial line was significantly higher with Dyna-3D than with 2D-DSA (p = 0.0001).

Conclusion

All-round 3D evaluation by Dyna-3D imaging appears useful for confirming in-stent neointimal formation after braided stent deployment in patients after stent-assisted coil embolization.

Usefulness of PETRA-MRA for Postoperative Follow-Up of Stent-Assisted Coil Embolization of Cerebral Aneurysms

Objective

Image evaluation after stent-assisted coil embolization (SAC) for a cerebral aneurysm is difficult with conventional MRA or CTA because of metal artifacts. Pointwise encoding time reduction with radial acquisition (PETRA)-MRA is a noninvasive imaging examination that can reduce metal artifacts. This study aimed to examine whether PETRA-MRA can be used as a follow-up imaging after SAC.

Methods

Twelve patients (eight women and four men; mean age, 66.9 ± 13.2 years) underwent SAC for unruptured aneurysms and were retrospectively evaluated using time-of-flight (TOF)- and PETRA-MRA data from the same follow-up session. Two neurosurgeons independently compared the aneurysm occlusion status and flow visualization score in the stented parent artery (4-point scale, where 4 points represented excellent visualization) between TOF- and PETRA-MRA images. If DSA was performed within 3 months before or after PETRA-MRA, the aneurysm assessment was compared between MRA and DSA. The interobserver agreement for each MRA was evaluated.

Results

Nine of the 12 patients underwent DSA within 3 months before and after TOF- and PETRA-MRA. The aneurysm occlusion status on DSA was more consistent with PETRA-MRA (eight of nine cases) than with TOF-MRA (one of nine cases; P = 0.023). The median visualization score of the stented parent artery was significantly higher for PETRA-MRA (4 [interquartile range {IQR} 3-4]) than for TOF-MRA (1 [IQR 1-1], P = 0.003). The interobserver agreement for evaluation of the aneurysm occlusion status and visualization score of the parent artery for PETRA-MRA were excellent (κ = 0.98 and 0.93, respectively). In one case, PETRA-MRA was able to detect aneurysm recurrence, leading to subsequent retreatment.

Conclusion

PETRA-MRA is a noninvasive examination that can be used to evaluate the occlusion status of aneurysms after SAC and visualize the stented parent artery. PETRA-MRA is useful for repeated follow-up examinations after SAC.

Antiplatelet therapy discontinuation after stent-assisted coil embolization for intracranial aneurysms: a single-center, long-term, retrospective, observational study

OBJECTIVE

The protocol for antiplatelet therapy after stent-assisted coil embolization (SACE) for intracranial aneurysms is not well established. In particular, the indications for single antiplatelet therapy (SAPT) discontinuation remain controversial. The authors investigated the long-term outcomes of SAPT discontinuation after SACE among patients at a single institution.

METHODS

Patients who underwent SACE during the period from 2010 to 2020 and who were followed up for > 1 year were included in this study. The delayed ischemic and hemorrhagic complication rates were examined during follow-up. Moreover, the risk factors of antiplatelet therapy reduction or discontinuation and the outcomes of SAPT discontinuation were examined.

RESULTS

In total, 240 patients were included in the analysis. The average patient age was 60.3 years, and the average follow-up period was 46.7 months. Nine (3.8%) patients presented with symptomatic delayed ischemic complication, and 3 (1.3%) patients experienced a decline in modified Rankin Scale score. The stent configuration (T- or Y-stent) was the only risk factor associated with delayed ischemic complication (p < 0.001). SAPT was discontinued in 147 (71.7%) of 205 patients who were followed up for > 2 years, and no ischemic complications were observed.

CONCLUSIONS

It is safe to discontinue SAPT in patients without ischemic complications and with stable intraaneurysmal signals on MRA 2 years after SACE. The T- or Y-stent is a high-risk factor for delayed ischemic complications, and antiplatelet therapy reduction or discontinuation should be cautiously considered.

Perioperative Antiplatelet Therapy for the Stent-Assisted Coil Embolization: Results of the Questionnaire Survey

Objective

This study aimed to determine the status of perioperative antiplatelet therapy in stent-assisted coil embolization (SAC) in Japan.

Methods

The questionnaire consisted of 13 questions and used Google forms, and was sent to institutions where endovascular specialists were employed. The results were analyzed.

Results

The responses from 307 centers indicated that the timing of initiation of antiplatelet therapy was 14 days-1 month before treatment in half of centers, and 7-14 days before treatment in the other half. Platelet function tests were performed at 165 centers (56.2%), of which 136 centers (46.3%) performed these tests for all patients, with the VerifyNow system being the most widely used tool. The duration of postoperative dual antiplatelet therapy was 6, 3, and 12 months in 169 (57.7%), 70 (23.5%), and 42 (14.3%) centers, respectively. The antiplatelet agents used for monotherapy were P2Y12 receptor antagonists or aspirin, with a postoperative period of up to 12 months in 139 centers (47.3%), 24 months in 68 centers (23.1%), and longer than 24 months in 50 centers (17%).

Conclusion

Current antiplatelet therapy for SAC in Japan varies widely among institutions. Moreover, each center has its own empirical rules for SAC. Therefore, the findings of this survey suggest the need to establish guidelines for optimal periprocedural antiplatelet therapy for SAC.

A Case of a Ruptured Microaneurysm at the Tip of the Basilar Artery With Right Abducens Nerve Palsy at the Time of the Initial Rupture and Rerupture During an Outpatient Follow-Up

The presentation of abducens nerve palsy after each occurrence of subarachnoid hemorrhage (SAH) is rare. Herein, we report the case of a patient with a ruptured microaneurysm at the tip of the basilar artery who presented with right abducens nerve palsy at the time of the initial rupture and rerupture during an outpatient follow-up. A 52-year-old woman developed SAH with right abducens nerve palsy, which was treated with coil embolization. One year after the initial SAH, there was a relapse of the SAH and paresis of the right abducent nerve palsy. This may have been caused by the location of the abducens nerve in relation to the surrounding structures, which were susceptible to the effects of hematoma or intracranial pressure fluctuations. Stent-assisted coil embolization is an effective treatment for regrowth that appears after endovascular therapy of microaneurysms.

Opposite L-configuration double stenting for rupture of an extremely wide-necked anterior communicating artery aneurysm at the acute stage: illustrative case

BACKGROUND

Wide-necked aneurysms can be treated by double stenting in an X- or Y-configuration or by a double waffle-cone technique. However, some aneurysms remain untreatable.

OBSERVATIONS

The rupture of a complex wide-necked anterior communicating artery (AcomA) aneurysm that caused acute subarachnoid hemorrhage (SAH) was treated successfully using double stents with an opposite L-configuration as an alternative to the X-stent technique. The aneurysm involved both A1-A2 junctions in the aneurysm neck with acutely oriented A2 segments of the anterior cerebral artery bilaterally. It was densely packed and completely obliterated angiographically with preserved blood flow by implanting each stent in the ipsilateral A1-A2 bilaterally. Blood flow from the left A1 to the right A2 was confirmed through the AcomA on injection of the left internal carotid artery immediately after the procedure without critical infarction in the subthalamic area. Although the AcomA was not demonstrated by injection of the left internal carotid artery on angiography at 3 months or 1 year later, no cerebral infarction was seen on magnetic resonance images at the final hospital visit.

LESSONS

Opposite L-configuration double stenting was used successfully as rescue stent-assisted coiling for a rupture of a complex wide-necked AcomA aneurysm in a patient with acute SAH.

Stent-Assisted Coil Embolization for Acute Ruptured Dissecting Aneurysm at the P2 Segment of the Posterior Cerebral Artery: A Case Report

Objective

We report a case of ruptured posterior cerebral artery (PCA) dissecting aneurysm treated with stent-assisted coil embolization in the acute phase of ruptured aneurysm.

Case Presentation

A 60-year-old woman presented with sudden onset of severe headache followed by unconsciousness. CT showed severe subarachnoid hemorrhage. Digital subtraction angiography showed a dissecting aneurysm at the P2 segment of the right PCA. Stent-assisted coil embolization was performed for the ruptured dissecting aneurysm. Since thrombus was observed in the stent, ozagrel was administered intravenously, and the thrombus gradually disappeared during the follow-up period. She was discharged without neurological deficit.

Conclusion

Parent artery occlusion is widely performed for acute ruptured PCA dissecting aneurysm, but reconstruction with stent-assisted coiling is considered to be an effective therapeutic strategy.

Stent-Assisted Coil Embolization of Ruptured Blood Blister-Like Aneurysm of the Basilar Artery: A Case Report and Literature Review

Objective

Blood blister-like aneurysms (BBA) often develop on the anterior wall of the internal carotid artery, and few cases have been reported at other sites. We report a case of stent-assisted coil embolization in the acute phase for a ruptured BBA of the basilar artery.

Case Presentation

A 53-year-old woman underwent emergency stent-assisted coil embolization for subarachnoid hemorrhage due to a ruptured BBA in the main trunk of the basilar artery. Seven months after the operation, cerebral angiography confirmed no recurrence and a good clinical course.

Conclusion

Stent-assisted coil embolization for BBA may be one treatment option.

A Case of Percutaneous Thrombectomy for Internal Carotid Artery Occlusion due to In-Stent Thrombosis Following Stent-Assisted Intra-Aneurysmal Embolization

Objective

In-stent thrombosis (IST) is a known complication after stent-assisted coil (SAC) embolization. We report a case of mechanical thrombectomy using a stent retriever (SR) for IST and share our experience with this treatment to prevent a poor outcome in future cases.

Case Presentation

The patient was a 62-year-old man. SAC embolization for an unruptured left internal carotid artery (ICA) aneurysm was performed. Three weeks after discharge, right hemiparesis and aphasia developed. Magnetic resonance imaging (MRI) demonstrated cerebral infarction in the left middle cerebral artery (MCA) territory and the left ICA was occluded. His relatives told us that the patient discontinued taking antiplatelet drugs. IST was diagnosed and emergency thrombectomy was performed. First, we tried to introduce an aspiration catheter or balloon catheter into the occluded lesion, but they were unable to be sufficiently inserted to the distal site. Therefore, we used a SR even though it carried a risk of friction on the deployed stent. The occluded artery was finally recanalized using the SR, but the stent became shortened. For the treatment strategy, sufficient medication (antithrombogenic agents and edaravone) should be administered first, followed by mechanical treatment. In mechanical treatment, thrombus fragmentation with a guidewire or balloon and aspiration should be attempted first. New aspiration catheters to carry the devices to the far distal site easily are now available.

Conclusion

SRs cannot be utilized for thrombectomy with a stent. In emergency situations, careful consideration during troubleshooting rather than using a SR is needed.

Retrograde T-Stent Technique for Large, Wide-Necked Internal Carotid-Posterior Communicating Artery Aneurysm

Objective

We report a case of a wide-necked internal carotid-posterior communicating (IC-Pcom) artery aneurysm treated by the retrograde T-stent technique in which a stent was also placed in the Pcom artery via the posterior circulation.

Case Presentation

A 35-year-old woman was diagnosed with an unruptured right IC-Pcom artery aneurysm (maximum diameter: 11 mm, neck diameter: 8.5 mm) during a detailed examination for vertigo. The Pcom artery (2.1 mm) branched from the aneurysmal dome. A microcatheter was guided in retrograde via the Pcom artery from the posterior circulation. A low-profile visualized intraluminal support (LVIS) Jr. 2.5 mm × 17 mm was deployed from the internal carotid artery (ICA) to the Pcom artery, and then, an LVIS 4.5 mm × 23 mm was deployed while pressing the flare of the LVIS Jr. protruding into the ICA. T configuration stenting was completed, and the coil was inserted as tightly as possible.

Conclusion

The retrograde T-stent technique, which has the advantage of optimal stent positioning, is useful for preserving a Pcom artery branching from the aneurysmal dome.

Stent-assisted coil embolization for an unruptured vertebral artery-posterior inferior cerebellar artery aneurysm with retrograde access via type 1 persistent primitive proatlantal artery: A case report

Vertebral artery (VA)-posterior inferior cerebellar artery (PICA) aneurysms are rare lesions that are difficult to treat with both endovascular and surgical techniques. Tight angulation of the PICA from VA may make access to the PICA difficult from ipsilateral VA if adjunctive techniques are needed. Recently, the safety and efficacy of retrograde access have been reported. We report a case of endovascular treatment for a VA-PICA aneurysm with a stent-assisted technique using retrograde access via contralateral persistent primitive proatlantal artery (PPA).The patient was a 76-year-old woman with an unruptured VA-PICA aneurysm on the dominant VA side. Coil embolization with a stent-assisted technique using retrograde access seemed appropriate. However, the origin of the left VA was not confirmed. Left common carotid artery angiography demonstrated that the PPA (type 1) branching from external carotid artery joined the VA V4 segment.Retrograde access via the PPA for stenting was performed. A microcatheter for stenting was retrogradely advanced to the right PICA at ease. After deploying the stent, coil insertion was completed from the right VA, and the final angiogram showed adequate occlusion of the aneurysm with preservation of the PICA.Thus, PPA may be an approach route in the treatment of VA-PICA aneurysms with unconfirmed contralateral VA orifice and apparent PPA on angiography, when retrograde access is needed.

Treatment Outcomes of Stent-Assisted Coil Embolization for Ruptured Vertebral Artery Dissecting Aneurysms: The Preservation of Branches May Improve the Prognosis

Objective

Subarachnoid hemorrhage due to ruptured vertebral artery dissecting aneurysm (rVADA) is associated with a high frequency of acute rebleeding and requires early treatment following onset. Parent artery occlusion (PAO) or stent-assisted coiling (SAC) embolization is selected as a treatment option according to the individual patient condition. This report is a retrospective examination evaluating the treatment outcomes for rVADA.

Methods

The subjects were 20 rVADA patients (16 men and 4 women) who underwent endovascular treatment at our institution. The mean patient age was 52.9 years. Ten patients each were allocated to the PAO group and SAC group. We evaluated and compared the following parameters: presence of hemorrhagic complications, presence of ischemic complications, requirement of retreatment, and Glasgow Outcome Scale (GOS) after 90 days.

Results

The reasons for selecting SAC were contralateral occlusion or a small diameter in three patients, the posterior inferior cerebellar artery (PICA) involvement in three patients, perforating artery from dissected lesion in five patients, and anterior spinal artery in one patient. There was no rebleeding in any patient. Symptomatic ischemic complications were observed in four patients in the PAO group and in one in the SAC group. Hyper-intense lesions in the brainstem on MRI DWI were noted in five patients in PAO group and in one in the SAC group. Retreatment was required for three patients in the PAO group and for four in the SAC group. Favorable outcomes (GOS 4, 5) after 90 days were observed for three patients in the PAO group and for eight patients in the SAC group (p = 0.0257).

Conclusion

SAC that can preserve branches is a useful treatment option for rVADA. Further studies on a greater number of subjects are required to establish the optimal dose of antiplatelet agents and anticoagulants, and for stent selection.

Strategies to Prevent Ischemic Complications after Stent-assisted Coil Embolization of Cerebral Aneurysms

Objective

There have been no delayed ischemic complications related to stent-assisted coil embolization (SACE) of cerebral aneurysms at our institution. We demonstrate our strategies for stent placement and postoperative management of antiplatelet therapy to reduce the risk of ischemic complications.

Methods

We analyzed 57 cases of SACE retrospectively. In the procedure, an appropriate stent was selected and placed to fit the arterial wall without impeding on small arterial branches. Two different antiplatelet drugs, including clopidogrel, were used. Six to twelve months after surgery, follow-up angiography was performed to assess the safety of terminating antiplatelet therapy. In cases in which antiplatelet therapy was tapered, the two antiplatelet drugs were switched to clopidogrel alone, and it was subsequently tapered and finally discontinued.

Results

There were 49 cases of SACE in which postoperative antiplatelet therapy was tapered. Among these cases, antiplatelet therapy was discontinued in 35 cases. The mean duration of dual antiplatelet therapy was 10.6 ± 2.8 months, and the mean duration of total antiplatelet therapy was 15.0 ± 2.1 months. Three patients developed SACE-related ischemic stroke, which developed in the early phase after surgery in all.

Conclusion

Antiplatelet therapy can safely be terminated in most cases of SACE. In order to reduce the risk of ischemic complications, stent selection, stent placement, and management of antiplatelet therapy should be performed appropriately. Furthermore, careful follow-up should be continued even after the termination of antiplatelet therapy.

Stent-assisted Coil Embolization to Treat Extracranial Carotid Artery Aneurysm 13 Years after Endarterectomy: A Case Report

Development of extracranial carotid artery aneurysm (ECCA) after carotid endarterectomy (CEA) is a rare complication, occurring in connection with <1% of all CEAs. The main causes are infection, suture failure, and degeneration of arterial wall or patch. The traditional treatment has been operative repair, which can present a significant technical challenge owing to reoperative neck inflammation and potential cranial nerve injuries. Here, we report a case of successful stent-assisted coil embolization for right noninfectious ECCA. A 63-year-old female was admitted to our hospital for a 3-cm pulsating mass in her right midneck. Doppler examination and digital subtraction angiography revealed a large (15 mm) ECCA at the right common carotid artery (CCA). Thirteen years earlier, eversion CEA with patch angioplasty and abbreviation of the internal carotid artery (ICA) had been performed for a symptomatic 80% diameter stenosis with transient ischemic attack at another hospital. As the patient refused blood transfusion for religious reasons, we treated her with stent-assisted coil embolization, which achieved nearly complete obliteration of the aneurysm while preserving the parent artery patency. Three months after initial treatment, ultrasound revealed complete occlusion of the ECCA, but also showed stent shortening. Hence, we performed an additional stent placement so as to overlap the previous stent by 2.5 cm. Six months after initial treatment, carotid duplex ultrasound confirmed a good outcome. This procedure is an excellent choice for high-risk patients, and a larger case series is needed to establish this technique as the treatment of choice for ECCAs.

Treatment of Recurrent Wide Neck Bifurcation Aneurysm With the Barrel Vascular Reconstruction Device

We present a case of successful embolization of a recurrent wide neck bifurcation aneurysm with a Barrel vascular reconstruction device (VRD). The unique properties of this novel device allowed optimal aneurysm neck coverage during third consecutive re-treatment, ultimately resulting in complete aneurysm obliteration. The parent vessel anatomy and the neck morphology of the aneurysm, in combination with a presence of a large pre-existing coil mass, were ideal for Barrel stent placement. The expanded portion of the device conformed perfectly to the recanalized aneurysm neck, providing optimal support for additional coil embolization. This case illustrates the advantages of Barrel VRD for definitive embolization of large, recurrent, and previously coiled wide-neck bifurcation aneurysm as a reasonable alternative to other traditional treatment modalities, such as flow diversion or Y and X stenting.

A persistent primitive hypoglossal artery-posterior inferior cerebellar artery convergence aneurysm treated by stent-assisted coil embolization: A case report

RATIONALE

Persistent primitive hypoglossal artery (PPHA) is often associated with intracranial anomalies such as aneurysms. Surgical treatment of aneurysms on the PPHA is challenging due to that the posterior circulation depends solely on PPHA.

PATIENT CONCERNS

A case of an 83-year-old woman with a large aneurysm on PPHA presented with vertigo was reported.

DIAGNOSIS

Three-dimensional angiogram revealed a wide-neck aneurysm on the PPHA.

INTERVENTIONS

The aneurysm was successfully treated using a novel low-profile visualized intraluminal support stent-assisted coiling technique.

OUTCOMES

No complications occurred during the procedure. The final angiogram confirmed the patency of the posterior inferior cerebellar artery and the parent artery and its distal branches.

LESSONS

Our case suggests that stent-assisted coil embolization is safe and effective for the treatment of aneurysms on the PPHA.

Treatment of acute thromboembolic complication after stent-assisted coil embolization of ruptured intracranial aneurysm: a case report

A 45-year-old Chinese man presented with acute severe headache for 2 days. He was diagnosed as subarachnoid hemorrhage. Head CT and subsequent head digital subtraction angiography (DSA) showed left internal carotid artery (ICA) aneurysm in the supraclinoid segment. Stent-assisted coil embolization of aneurysm was performed. Three hours after the surgery, the patient was found to be drowsy and with paralysis of the right limb and slurred speech. Urgent head CT examination ruled out acute hemorrhage; however, DSA showed acute thrombosis in the left ICA between the branches of the ophthalmic artery and middle cerebral artery, which was probably from an acute in-stent thrombosis. Urokinase (100,000 units) was given through a micro-tube but failed to dissolve the thrombus; thus, stent embolectomy was performed, which successfully removed the thrombus. Repeat angiography showed that the left ICA was completely recanalized. Postoperatively, the patient regained consciousness and was well-limbed and fluent in speech. No neurological symptoms or signs were found at 6-, 12-, and 24-month follow-up.

Evaluation of Acute In-stent Thrombosis during Stent-assisted Coil Embolization of Unruptured Intracranial Aneurysms

Stent-assisted coil embolization (SACE) is used to address wide-necked or complex aneurysms. However, periprocedural and/or late in-stent thrombosis (IST) elicit neurological events. We investigated the incidence and timed the development of acute IST during SACE with braided- or laser-cut stents in a retrospective study. Between May 2013 and April 2018, we evaluated 11 ISTs that occurred in the course of 185 SACE procedures (self-expandable laser-cut stent, n = 128; braided stent, n = 57). The onset of IST was measured from the time of stent placement. All 11 patients with IST were treated with anticoagulants and underwent hypertension induction. Post-procedural neurological events due to IST were also recorded. The implantation of a laser-cut stent elicited IST in 5 of 128 patients (3.9%); braided stent placements resulted in IST in 6 of 57 patients (10.5%) (P = 0.1). The mean stent diameter was significantly smaller in patients with-IST than without IST (3.0 ± 0.9 mm vs. 4.5 ± 0.7 mm, P = 0.007). The mean interval between stent placement and IST onset was 19 ± 7.7 min; it was significantly earlier for braided- than laser-cut stents (17.5 ± 4.1 min vs. 29.0 ± 4.8 min, P = 0.006). All ISTs were resolved during the procedure. Three patients experienced postoperative neurologic events. We recommend the meticulous and prolonged monitoring of images after stent placement because delayed intraoperative IST can occur especially when laser-cut stents are used.

Jailed double-microcatheter technique following horizontal stenting for coil embolization of intracranial wide-necked bifurcation aneurysms: A technical report of two cases

The horizontal stenting technique facilitates endovascular treatment of wide-necked bifurcation intracranial aneurysms. Previous literature shows, however, that subsequent coil embolization at initial treatment results in incomplete obliteration in many cases. The authors present two consecutive cases of wide-necked large bifurcation aneurysms to describe an additional coil embolization technique following horizontal stenting. The patients were a 53-year-old female with an unruptured internal carotid artery terminus aneurysm and a 57-year-old female with a recurrent basilar artery tip aneurysm. Both patients underwent endovascular treatment with horizontal stenting followed by coil embolization with jailed double-microcatheters. Immediate complete obliteration was achieved with no complications, and no recanalization was observed at the one-year follow-up in both cases. Coil embolization with jailed double-microcatheter technique following horizontal stenting is a safe and effective strategy for wide-necked bifurcation aneurysms.

Stent-assisted coil embolization for anterior cerebral artery dissection presented with cerebral infarction

BACKGROUND

Compared to those found in the vertebrobasilar system, intracranial dissection in the anterior circulation is relatively rare, especially in the anterior cerebral artery (ACA). Moreover, only several cases of ACA dissection that underwent endovascular treatment have been reported. Here we present a rare case of gradually developing ACA dissecting aneurysm causing cerebral infarction, successfully treated by stent-assisted coil embolization.

CASE DESCRIPTION

A 36-year-old man was admitted with sudden right hemiparesis. Diffusion-weighted magnetic resonance (MR) imaging showed cerebral infarction in the left ACA territory, and MR angiography showed segmental stenosis at the A2 portion of the left ACA. Three-dimensional digital subtraction angiogram showed segmental dilatation and stenosis at the left A2 portion. We diagnosed ACA dissection causing acute cerebral infarction and treated the patient conservatively. Five months after the onset, the dissecting artery at the left A2 portion formed a gradually dilating aneurysm, suggesting increased risk for aneurysmal rupture. We attempted endovascular treatment entailing coil embolization of an aneurysm while preserving the left A2 with stent assistance. The patient remained neurologically stable 6 months after the procedure.

CONCLUSIONS

Although there are few reported cases of ACA dissection where endovascular treatment was attempted, we consider stent-assisted embolization for gradually developing ACA dissecting aneurysm as an alternative method to prevent bleeding and recurrent infarction.

The "temporary caging" technique for catheter navigation in patients with intracranial wide-necked aneurysms

Endovascular treatment of wide-necked aneurysms with preservation of the parent artery remains a challenge. The authors describe a novel and simple technique to navigate a balloon or stent-delivery catheter across a wide-necked aneurysm in which previously existing methods could have failed to pass the catheter across the neck of the aneurysm, which we have named "temporary caging" technique. The technical results using this method are presented in 6 cases.

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.

Stent-Assisted Coil Embolization of a Wide-Neck Aneurysm at the Vertebral Artery Terminus Using a Contralateral Approach: A Technical Report

BACKGROUND

Aneurysms of the vertebrobasilar junction (VBJ) are especially uncommon but carry a significant risk of hemorrhage and historically have been difficult to treat. In recent years, however, advancements in stent-assisted embolization have allowed better access and stabilization of complicated posterior circulation aneurysms.

METHODS

We describe a novel approach in the treatment of a wide-neck aneurysm at the terminus of the left vertebral artery by a contralateral approach in a patient with ipsilateral subclavian artery occlusion.

RESULTS

A complex, wide-neck aneurysm at the verterbrobasilar junction hindered by ipsilateral subclavian occlusion can successfully be treated with stent-assisted coil embolization using a contralateral approach.

CONCLUSION

Contralateral U-shaped stenting offers a viable endovascular option for patients with complex aneurysms of the vertebral basilar junction but should be reserved for appropriate cases with favorable anatomy when the ipsilateral approach from the subclavian artery is unobtainable.

Stent-assisted coil embolization of ruptured wide-necked aneurysms in the acute period: incidence of and risk factors for periprocedural complications

OBJECT.: The purpose of this study was to report the authors' experiences in stent-assisted coil embolization (SAC) of ruptured wide-necked aneurysms in the acute period and to evaluate the incidence of and risk factors for periprocedural complications.

METHODS

A total of 72 patients were recruited for this study between March 2007 and June 2012. All patients met the following criteria: 1) the presence of ruptured intracranial wide-necked saccular aneurysms, and 2) the patient underwent SAC for treatment of those aneurysms within 72 hours of rupture. All of the patients with clinically poor grades or acute hydrocephalus underwent external ventricular drainage (EVD) before SAC. The incidence of and risk factors for periprocedural complications were retrospectively evaluated.

RESULTS

Of the 72 patients included in this study, periprocedural complications occurred in 14 (19.4%), including asymptomatic complications in 4 (5.6%) and symptomatic complications in 10 (13.9%); there were symptomatic thromboembolic complications in 5 patients (6.9%), and symptomatic hemorrhagic complications in 5 (6.9%). The authors observed no subacute or delayed thromboembolic complications during the follow-up period of 18.8 months. Use of EVD (OR 1.413, 95% CI 0.088-2.173; p = 0.046) was the only independent risk factor for periprocedural complications on multivariate logistic regression analysis.

CONCLUSIONS

The periprocedural complication rate during SAC was 19.4% among 72 patients. Because of the high complication rate, microsurgical clipping or endovascular treatment with another technique (multiple-microcatheter or balloon-assisted technique) may be a more appropriate option for first-line treatment than SAC, especially in patients requiring EVD.

Balloons and stents in the endovascular treatment of cerebral aneurysms: vascular anatomy remodeled

Wide-neck intracranial aneurysms were originally thought to be either untreatable or very challenging to treat by endovascular means because of the risk of coil protrusion into the parent vessel. The introduction of the balloon remodeling technique (BRT) and later stents specifically designed for intracranial use has progressively allowed these lesions to be endovascularly treated. BRT and stent-assisted coiling technique (SACT) were first designed to treat sidewall aneurysms but, with gained experience and further technical refinement, bifurcation complex-shaped wide-neck aneurysms have been treated by coiling enhanced by BRT and SACT. In this article, we will review and describe the inherent benefits and drawbacks of BRT as well as SACT.

Onset Time of Ischemic Events and Antiplatelet Therapy after Intracranial Stent-assisted Coil Embolization

BACKGROUND

Stent-assisted coil embolization is effective for intracranial aneurysms, especially wide-necked aneurysms; however, the optimal antiplatelet regimens for ischemic events that develop after coil embolization have not yet been established. We aimed to determine the onset time of such postoperative ischemic events and the relationship between these events and antiplatelet therapy.

METHODS

We performed coil embolization using a vascular reconstruction stent for 43 cases of intracranial aneurysms and evaluated the incidence of postoperative ischemic events in these cases.

RESULTS

Nine patients showed postoperative ischemic events during the follow-up period (13 ± 7 months). Two patients developed cerebral infarction within 24 hours. Five patients developed transient ischemic attack within 40 days while they were receiving dual antiplatelet therapy. In addition, 1 patient showed cerebral infarction 143 days postoperatively during single antiplatelet therapy, and a case of transient visual disturbance was reported 191 days postoperatively (49 days after antiplatelet therapy had been discontinued). We increased the number of antiplatelet agents in 4 of these patients. The other 5 patients were under strict observation with dual antiplatelet therapy. All these patients were shifted to single antiplatelet therapy 3-13 months postoperatively. No recurrence of ischemic events was noted.

CONCLUSIONS

Postoperative ischemic events are most likely to occur within 40 days postoperatively. For patients with postoperative ischemic events, additional ischemic events can be prevented by increasing the number of antiplatelet agents; subsequently, they can be shifted to single antiplatelet therapy after the risk of recurrence has decreased.