Retrograde stenting through the posterior cerebral artery in coil embolization of the posterior communicating artery aneurysm

A Radial Approach Combined With a Contralateral Vertebral Retrograde Approach for Stenting and Coil Embolization of a Large Posterior Inferior Cerebellar Artery Aneurysm

BACKGROUND

Wide-neck aneurysm embolism is a technically demanding procedure. Stent device deployment is challenging intraoperatively, especially in parent arteries with acute angles.

CASE DESCRIPTION

The authors describe the case of a 74-year female with an unruptured right posterior inferior cerebellar artery aneurysm. The acute angle of the arteries proximal to the posterior inferior cerebellar artery complicated the condition, and the distal end of the guidewire failed to enter the posterior inferior cerebellar artery despite several maneuvers. The wide neck of the aneurysm was located in the posterior inferior cerebellar artery, so a stent was needed. The stent was deployed from the left vertebral artery retrograde to the right vertebral artery.

CONCLUSIONS

The authors report the successful application of a rare strategy, the radial approach combined with a contralateral vertebral retrograde approach, for stent deployment.

Retrograde placement of flow diversion for the treatment of giant internal carotid artery aneurysm

The use of flow diverters has been well-validated for the treatment of giant internal carotid artery aneurysms. However, in certain complex cases, the navigation of stent microcatheters across the neck may pose a relative challenge.1-3 In this technical video (video 1), we present the case of a patient in their 50s experiencing discomfort in the left eye. Angiography identified a giant aneurysm in the ophthalmic segment of the left internal carotid artery. Before seeking care at our institution, the patient had two interventional procedures, both unsuccessful due to difficulties in navigating the microcatheter past the aneurysm neck.4-5 In our management, after multiple unsuccessful anterograde attempts, we employed a retrograde strategy via the vertebral-basilar-posterior communicating artery route. This approach facilitated the successful deployment of the flow diverter and led to effective aneurysm embolization, underscoring the value of retrograde techniques for challenging cases.

Endovascular Treatment of Intracranial Aneurysms Using a Microcatheter Protection

PURPOSE

Stent protective or balloon remodeling techniques have enabled coil embolization of complexly configured aneurysms. Still, the utility of such methods may be limited in some small-caliber and/or inherently tortuous lesions. The present study was conducted to examine the efficacy of microcatheter protection (MCP) when applied in these circumstances.

METHODS

This retrospective review included 432 patients with 452 intracranial aneurysms subjected to MCP between April 2001 and January 2021. All available medical records and radiologic data were analyzed, focusing on strategic, safety, and efficacy aspects of the procedures.

RESULTS

In a majority (255/452, 56.4%) of cases, MCP was applied throughout entire coiling procedures, as opposed to coil framing (137/452, 30.3%) or filling/finishing (60/452, 13.3%) only. Lesions of the middle cerebral artery (54.9%) predominated, followed by anterior (12.4%) and posterior (11.1%) communicating artery aneurysms. Stent protection was also used occasionally (46/452, 10.2%). Procedural morbidity was low (3/432, 0.7%), limited to symptomatic thromboembolism and procedural leakage, and there were no deaths. Occlusion was successfully achieved by MCP in 424 aneurysms (93.8%). During the follow-up period (mean, 43.4 ± 30.4 months), satisfactory occlusion was documented in 406 of 440 (92.3%) aneurysms.

CONCLUSION

MCP is feasible and safe for coil embolization of intracranial aneurysms, in conjunction with multicatheter, balloon, or stenting techniques. MCP may have merit in small-sized or tortuous lesions not amenable to balloon or stent usage, often eliminating the need for stenting altogether.

The Rationale Behind Transcirculation Neuroendovascular Interventions: Literature Review Through a Case-Series Approach

BACKGROUND

With the development of advanced endovascular techniques and materials, neurointerventionalists can perform challenging and complex cases that were previously difficult to perform. Transcirculation approaches could be a useful tool used in complicated cases, providing access to the target vessel, through the contralateral or opposite circulation, when anterograde access is difficult or nonachievable.

OBJECTIVE

To retrospectively review cerebrovascular interventions performed through a transcirculation approach performed by staff at our Institution.

METHODS

English-language studies, published until August 2022, reporting transcirculation interventions in the cerebrovascular circulation were retrospectively collected. Type of intervention, number of cases, rationale, and complications were analyzed. Furthermore, similar cases performed by staff currently at our institution were also reviewed and described.

RESULTS

Including our cases, a total of 273 transcirculation treatment approaches have been reported. Intracranial aneurysm embolization, stroke thrombectomies, intra-arterial ophthalmic chemotherapy, arteriovenous malformationss, arteriovenous fistulas embolizations, and intracranial angioplasty and stenting are common indications. Reason for using a retrograde approach were stent/balloon-assisted coiling of wide neck aneurysm in 116 cases, difficult angulation of branch in 91 cases, occlusion of parent vessel in 55 cases, and bailout/other in 11 cases.

CONCLUSION

Transcirculation approaches can be considered for cases where conventional anterograde treatment options are not feasible or as a bailout strategy in failed or complicated treatment attempts. They represent a strategy to consider when facing challenging cases, and if performed by experienced and dedicated neurointerventionalists, they can represent a safe alternative.

Application of the Neuroform Atlas Stent in Intracranial Aneurysms: Current Status

The Neuroform Atlas stent (NAS) is the successor of the Neuroform EZ stent. The NAS is compatible with a low-profile 0.0165-inch microcatheter and is soft enough to pass through small and highly tortuous vessels. The NAS can be used in treating intracranial aneurysms at almost all locations, and its use is becoming increasingly common. However, there has not yet been a complete review of NAS applications. Therefore, we performed this review, which addresses several aspects of the NAS, mainly including its characteristics, clinical trials of its application in treating aneurysms, deployment techniques for the device, the prognosis and complications of its application in treating aneurysms, and antiplatelet requirements associated with its use. Based on the evidence reviewed here, as well as our experience, we found that the NAS is a promising device for treating intracranial aneurysms, especially complex and distal aneurysms. This stent can also be used as a powerful tool to assist in rescuing coil migration, completing dual-stent reconstruction, and coiling aneurysms via a transcirculation approach. The device may require antiplatelet therapy at a lower dose and over a shorter period than other stents. The deployment of the NAS to assist in aneurysm coiling can yield good clinical outcomes and an acceptable rate of complications. Thus, the NAS is a promising device.

Coil embolization with overlapping horizontal low-profile stents to treat a giant thrombosed fetal posterior cerebral artery aneurysm using contralateral approach through anterior communicating artery: Case report

Background

The treatment of internal carotid artery (ICA) - posterior communicating artery aneurysms (ICPC aneurysms) is challenging when a fetal posterior cerebral artery (PCA) arises from the saccular neck. This complex angioarchitecture renders endovascular approaches difficult. Giant thrombosed IC-PC aneurysms are also hard to treat by endovascular coiling because its flow-diversion effect is insufficient.

Case Description

We report the first case of a ruptured giant thrombosed IC-PC aneurysm associated with a fetal PCA that was successfully treated by coil embolization with retrograde overlap horizontal stenting using low-profile stents introduced through the contralateral ICA. The aneurysm was completely occluded and follow-up MRI scans demonstrated the reduction of the aneurysmal size.

Conclusion

Our technique is advantageous because low-profile stents can be used to treat lesions not accessible with flow-diverter stents due their presence in complex angioarchitectures, and overlap stenting may have flow-diversion effects that can result in the complete occlusion of giant thrombosed aneurysms.

T-Stent or Half T-Stent-Assisted Embolization of Wide-Necked Aneurysms at the Internal Carotid-Posterior Communicating Artery Bifurcation

Objective

We report the usefulness and pitfalls of coil embolization using the T or half T-stent technique for aneurysms located at internal carotid artery-posterior communicating artery (ICA-P-com) bifurcation in which the neck is wide and the P-com must be kept patent due to it being the fetal-type with a hypoplastic P1 segment.

Case Presentations

Two cases were treated using the T-stent technique and two were treated using the half T-stent technique. The average age of the patients was 70.3 years and all were females. One aneurysm ruptured. The average size of aneurysms and neck was 12 mm and 8.5 mm, respectively, in the T-stent group, and 7.4 mm and 6.7 mm, respectively, in the half T-stent group. An S- or pigtail-shaped microcatheter (MC) was used to navigate into the P-com. Stent deployment was successful in all the cases. Retreatment was required in one case treated using the T-stent technique due to major recurrence.

Conclusion

T or half T-stent-assisted coil embolization can be an alternative endovascular treatment method for wide-necked ICA-P-com aneurysms in which the P-com must be kept patent due to it being the fetal-type with a hypoplastic P1 segment.

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.

Transcirculation approach for stent-assisted coiling of intracranial aneurysms: a multicenter study

BACKGROUND

The transcirculation approach (TCA) for stent-assisted coiling (SAC) of intracranial aneurysms may be useful for certain wide-neck bifurcation aneurysms as well as those with acute-angle efferent branches.

OBJECTIVE

To describe a multicenter experience using the TCA for SAC.

METHODS

A multicenter, retrospective study (2016-2020) of aneurysm treatment using SAC via the TCA. Angiographic outcome was scored using the Raymond Scale (adequate occlusion 1 and 2), and clinical outcome was scored using a modified Rankin Scale (good outcome 0-2) RESULTS: Twenty-nine patients with 29 aneurysms were included (62.1% female; average age 61; 89.7% unruptured; 13.8% previously treated; average dome size 6.4 mm; average neck 4.4 mm). Aneurysm locations included internal carotid artery-fetal posterior cerebral artery (n=4), internal carotid artery terminus (n=4), anterior communicating artery (n=8), vertebral artery-posterior inferior cerebellar artery (n=2), and basilar tip (n=11). The TCA used communicating arteries (93.1%; average 1.6 mm), intermediate catheters (51.7%), jailing technique (62.1%), and staged procedures (10.3%). The most common stent was the Neuroform Atlas (Stryker; 69%). Immediate adequate occlusion was obtained in 75.9%, and five patients with inadequate occlusion progressed to adequate occlusion at follow-up. One (3.4%) procedural complication occurred: a watershed stroke in the setting of baseline four-vessel extracranial disease. Two patients had a poor outcome unrelated to the TCA. The majority of patients (86.4%) had a good clinical outcome. One case of in-stent stenosis due to non-compliance with medication was seen, which resolved with medication resumption.

CONCLUSIONS

The TCA for SAC can be performed for a variety of aneurysms with a low complication rate and good clinical outcomes.

Preliminary experience of stent-assisted coiling of wide-necked intracranial aneurysms with a single microcatheter

BACKGROUND

The purpose of this study was to report our preliminary experience of stent-assisted coiling (SAC) of wide-necked intracranial aneurysms with a single microcatheter in patients with parent arteries that were small-caliber, with stenosis, or a very tortuous course.

METHODS

Between March 2018 and December 2018, we treated 394 aneurysms in 359 patients with endovascular treatment. Among 197 aneurysms treated by SAC, there were 16 cases (all wide-necked unruptured aneurysms) treated by SAC with a single microcatheter and a Neuroform Atlas stent. Follow-up angiography was performed at 6 to 12 months after SAC, and clinical follow-up was performed from 6 to 12 months in all patients.

RESULTS

The reasons for SAC with a single 0.0165-in. microcatheter were small-caliber (n = 4), stenosis (n = 2), and very tortuous course (n = 10) of the parent arteries. There was no complication related to delivering or deploying the Neuroform Atlas stent as well as no failure of selecting aneurysm by cell-through technique. All patients had a modified Rankin score of 0 at discharge and at follow-up. Initial angiographic results showed six cases (37.5%) of complete occlusion. In follow-up angiographies, 12 cases (75.0%) achieved compete occlusion.

CONCLUSION

When performing SAC of wide-necked intracranial aneurysms in parent arteries with small-caliber, stenosis, or a very tortuous course, cell-through SAC using a single microcatheter and a Neuroform Atlas stent within a 5 Fr- (or smaller) guiding or intermediate catheter might be a useful option.

Treatment of true posterior communicating artery aneurysms: Endovascular experience in a single center

BACKGROUND AND OBJECTIVE

The true posterior communicating artery (TPCoA) aneurysms are rare and endovascular treatment for such lesions is limited in literature.

METHODS

From January 2012 to March 2017, eight TPCoA aneurysms were treated endovascularly and included in our present study. The procedural complication and outcomes were assessed.

RESULTS

Seven of eight aneurysms (87.5%) were ruptured. Stent-assisted coiling was used in one case that a stent was deployed via PCoA-ipsilateral P2 segment. The dual-microcatheter technique was used in one case. The remaining six cases were treated by coiling alone. One patient (12.5%) suffered perioperative complication, of which a coil herniated into parent vessel during the procedure without symptomatic stroke or other adverse event after the procedure. The initial embolization results showed complete occlusion in five cases and residual neck in three. Six patients (75%) had a mean of 15-month angiographic follow-up and two of them revealed recurrence (33.3%). Clinical follow-up was available in seven patients (87.5%) and all patients showed favorable clinical outcome with mRS score 0.

CONCLUSION

TPCoA aneurysms are rare and challenging lesions with high rupture rate in literatures. Endovascular treatment may be a feasible alternative for TPCoA aneurysms. Primary coiling, as well as adjunctive strategies, such as stent-assisted coiling or dual catheter techniques may be considered. Further study in a larger population is necessary.

Retrograde stenting through anterior communicating artery in coil embolization of the posterior communicating artery aneurysm: contralateral approach

During coil embolization of wide-necked posterior communicating artery (PcomA) aneurysms, stent assistance is sometimes limited if PcomA is acutely angled at its origins from saccular neck. Herein, we present two instances where retrograde stenting was used for coil embolization of PcomA aneurysms. Both procedures involved a contralateral approach via anterior communicating artery (AcomA). To achieve this, the stent-delivery microcatheter was inserted retrograde from contralateral to ipsilateral internal carotid artery (ICA) across AcomA, arriving at ipsilateral PcomA. A separate microcatheter, passed through ipsilateral ICA, was then used to select the aneurysm sac for coil delivery. Coil embolization ultimately took place under protection of a horizontally placed stent extending from PcomA to terminal ICA. Each aneurysm was properly coiled and occluded, without procedural complications. This stenting technique is a reasonable option, offering a means of strategic coil embolization in wide-necked PcomA aneurysms and providing complete neck coverage through contralateral access.

Contralateral Approach to Coil Embolization of Proximal A1 Aneurysms Using the Anterior Communicating Artery

BACKGROUND AND PURPOSE

Aneurysms arising from the proximal A1 segment of the anterior cerebral artery are rare, and their distinctive configurations often pose technical challenges during endovascular embolization. Herein, we present 11 patients with proximal A1 aneurysms requiring a contralateral approach (via the anterior communicating artery) to coil embolization.

MATERIALS AND METHODS

From a prospectively collected data repository, we retrieved records of 11 patients consecutively treated for proximal A1 aneurysms between January 2011 and March 2018. In each instance, coil embolization was performed by the contralateral route. Outcomes were analyzed in terms of morphologic features and clinical status.

RESULTS

Aneurysms in all 11 patients were directed posteriorly and were small (<5 mm). A contralateral approach (via the anterior communicating artery) was used after ipsilateral attempts at aneurysm selection failed in each instance, despite using a variety of microcatheters. Single punctures and single guiding catheters sufficed in 9 patients, but 2 patients required dual punctures and 2 guiding catheters. All endovascular treatments ultimately yielded excellent outcomes. Although 1 symptomatic infarct was manifested in the course of ipsilateral treatment, no morbidity or mortality resulted from the contralateral access.

CONCLUSIONS

Due to angio-anatomic constraints, a contralateral strategy for coil embolization of proximal A1 aneurysms is acceptable if ipsilateral access is technically prohibitive and the vessels (contralateral A1 and anterior communicating artery) are amenable to the passage of microdevices.