Endovascular Treatment of Wide-necked Cerebral Aneurysms with an Acute Angle Branch Incorporated into the Sac: Novel methods of Branch Access in 8 Aneurysms

How does the recurrence-related morphology characteristics of the Pcom aneurysms correlated with hemodynamics?

Introduction

Posterior communicating artery (Pcom) aneurysm has unique morphological characteristics and a high recurrence risk after coil embolization. This study aimed to evaluate the relationship between the recurrence-related morphology characteristics and hemodynamics.

Method

A total of 20 patients with 22 Pcom aneurysms from 2019 to 2022 were retrospectively enrolled. The recurrence-related morphology parameters were measured. The hemodynamic parameters were simulated based on finite element analysis and computational fluid dynamics. The hemodynamic differences before and after treatment caused by different morphological features and the correlation between these parameters were analyzed.

Result

Significant greater postoperative inflow rate at the neck (Qinflow), relative Qinflow, inflow concentration index (ICI), and residual flow volume (RFV) were reported in the aneurysms with wide neck (>4 mm). Significant greater postoperative RFV were reported in the aneurysms with large size (>7 mm). Significant greater postoperative Qinflow, relative Qinflow, and ICI were reported in the aneurysms located on the larteral side of the curve. The bending angle of the internal carotid artery at the initiation of Pcom (αICA@PCOM) and neck diameter had moderate positive correlations with Qinflow, relative Qinflow, ICI, and RFV.

Conclusion

The morphological factors, including aneurysm size, neck diameter, and αICA@PCOM, are correlated with the recurrence-inducing hemodynamic characteristics even after fully packing. This provides a theoretical basis for evaluating the risk of aneurysm recurrence and a reference for selecting a surgical plan.

Efficacy and safety of guidewireless catheterization with a steerable microcatheter in patients scheduled for yttrium-90 radioembolization: a prospective multicenter trial

Introduction

A steerable, guidewireless microcatheter is of interest to interventional radiologists because it can improve effectiveness and reduce procedure timing and cost.

Aim

To assess the feasibility and safety of yttrium 90 radioembolization with a new steerable microcatheter without the need to use a guidewire.

Material and methods

A steerable microcatheter (Direxion; Boston Scientific, Natick, MA, USA) was prospectively used for yttrium-90 microsphere delivery in 50 patients (57 applications). The following factors were documented: vessel anatomy; shape and position of the guiding catheter; anticipated catheter position; technical success of catheterization; degree of difficulty in maneuvering; time to reach the target position; and complications.

Results

The microcatheter target position was in the right hepatic artery (n = 30, 53%), the middle hepatic artery (n = 4, 7%), the left hepatic artery (n = 19, 33%), or in a segmental artery (n = 4, 7%). Vessel catheterization was successful in 53 of 57 hepatic arteries (93%). The mean time to reach the target position was 53.3 ±53.0 s. The mean degree of difficulty in maneuvering the catheter to the target position was 2.3 ±1.3 (easy) on a 6-point scale. The only complication observed was mild vasospasm in 1 patient.

Conclusions

The Direxion steerable microcatheter is characterized by unique steerability, allowing yttrium 90 delivery to be performed safely without use of a guidewire.

Endovascular Treatment of Wide Neck Aneurysms

BACKGROUND

An aneurysm is an abnormal focal dilatation of an artery. Most of the unruptured aneurysms are asymptomatic and discovered incidentally or some of them symptomatic with mass effect or nerve palsy, but rupture of aneurysm results in a potentially life-threatening subarachnoid haemorrhage. Aneurysms with wide necks are defined by neck diameters greater than 4 mm or dome-to-neck ratios less than 2 and are the most difficult to treat with the endovascular method.

AIM

This study aimed to analyse the endovascular treatment of intracranial aneurysms with a wide neck.

METHODS

The study population included 37 patients with 46 aneurysms referred to the University Clinic of Radiology in Skopje, the Republic of Macedonia for endovascular treatment during the period January 2013 to May 2018. This study included 24 females and 13 males, ranging in age from 25 to 74 years.

RESULTS

From total 46 treated aneurysms 13 were ruptured and 33 unruptured. Six patients were with multiple aneurysms. In these study complex aneurysms were treated with combined technique, 5 with balloon-assisted coiling, 25 with stent-assisted coiling, 6 stents, 2 with flow diverter assisted coiling, 6 FD and 2 with partial coil filling without assistance device.

CONCLUSION

Aneurysms with wide neck remain a challenge for endovascular treatment. But the development of new techniques and materials in the treatment of aneurysms makes endovascular treatment of intracranial aneurysms safe and feasible.

Microcatheter Looping Technique Facilitates the Embolization of Complex Intracranial Aneurysms with an Acute Angle Branch Incorporated into the Sac

OBJECTIVE

Intracranial aneurysms with an acutely angled parent vessel are difficult to enter using conventional techniques. This study examined efficacy, safety, and technical aspects of intraluminal, intra-aneurysmal, and in vitro microcatheter looping techniques (MLTs).

METHODS

MLTs were used to treat intracranial aneurysms with an incorporated acute angle branch in 29 consecutive patients after failed treatment with conventional techniques. The MLT was adopted based on specific morphologic traits of aneurysms and parent vessels. Narrow-necked aneurysms were generally treated with coiling alone, whereas wide-necked aneurysms and giant aneurysms were treated with stent-assisted coiling.

RESULTS

Technical success was achieved in 28 of 29 cases (96.6%). In vitro MLT was used in 12 patients, intraluminal MLT was used in 14 patients, and intra-aneurysmal MLT was used in 3 patients. Immediate total occlusion was achieved in 8 patients, near-total occlusion was achieved in 8 patients, and subtotal occlusion was achieved in 13 patients.

CONCLUSIONS

The MLT may provide access to an incorporated, acutely angled arterial branch that is difficult to enter using a conventional coiling technique. The in vitro MLT is potentially safer than intraluminal and intra-aneurysmal MLTs because the loop is very stable and requires less manipulation.

Tirofiban combined with urokinase selective intra-arterial thrombolysis for the treatment of middle cerebral artery occlusion

The aims of the present study were to establish a model of embolic stroke in rabbits and to evaluate the efficacy and safety of intra-arterially administered tirofiban combined with urokinase thrombolysis. The middle cerebral artery occlusion model (MCAO) of embolic stroke was established in New Zealand rabbits via an autologous clot. The model rabbits were allocated at random into four groups: Tirofiban group (T group), urokinase group (UK group), tirofiban and urokinase group (T + UK group) and the control group (C group). The recanalization rate, relative-apparent diffusion coefficient (rADC) and neurological function deficit score (NFDS) values were compared among the four groups. The recanalization rate, rADC and NFDS values were improved in the T + UK group compared with the other groups. In summary, the intra-arterial administration of tirofiban combined with urokinase thrombolysis was a more effective intervention in an MCAO model compared with intra-arterial urokinase alone, and may promote reperfusion and reduce infarct volume.

Microcatheter Looping to Facilitate Aneurysm Selection in Coil Embolization of Paraclinoid Aneurysms

Objective

Described herein is a microcatheter looping technique to facilitate aneurysm selection in paraclinoid aneurysms, which remains to be technically challenging due to the inherent complexity of regional anatomy.

Materials and Methods

This retrospective study was approved by our Institutional Review Board, and informed consent was waived. Microcatheter looping method was employed in 59 patients with paraclinoid aneurysms between January 2012 and December 2013. In the described technique, construction of a microcatheter loop, which is steam-shaped or pre-shaped, based on the direction of aneurysms, is mandatory. The looped tip of microcatheter was advanced into distal internal carotid artery and positioned atop the target aneurysm. By steering the loop (via inner microguidewire) into the dome of aneurysm and easing tension on the microcatheter, the aneurysm was selected. Clinical and morphologic outcomes were assessed with emphasis on technical aspects of the treatment.

Results

Through this looping technique, a total of 59 paraclinoid aneurysms were successfully treated. After aneurysm selection as described, single microcatheter technique (n = 25) was most commonly used to facilitate coiling, followed by balloon protection (n = 21), stent protection (n = 7), multiple microcatheters (n = 3), and stent/balloon combination (n = 3). Satisfactory aneurysmal occlusion was achieved through coil embolization in 44 lesions (74.6%). During follow-up of 53 patients (mean interval, 10.9 ± 5.9 months), only one instance (1.9%) of major recanalization was observed. There were no complications related to microcatheter looping.

Conclusion

This microcatheter looping method facilitates safe and effective positioning of microcatheter into domes of paraclinoid aneurysms during coil embolization when other traditional microcatheter selection methods otherwise fail.

Coiling of a recurrent broad-necked posterior communicating aneurysm incorporating a fetal cerebral artery: A technical case report

We describe a case of a right broad-necked posterior communicating artery (PcomA) aneurysm with a fetal posterior cerebral artery (PCA) incorporated in the aneurysm neck. We performed waffle cone stent-assisted coiling and achieved almost complete occlusion of the aneurysm. At 18-month follow-up angiography, the aneurysm was recanalized and further coiling was needed. The same waffle cone method of coiling might be expected to produce the same unsatisfactory results on follow-up, so we decided to use retrograde stent navigation and placement through the anterior communicating artery (AcomA) from the contralateral internal carotid artery (ICA) to the ipsilateral ICA and fetal PCA. The stent delivery microcatheter from the contralateral ICA could not be introduced in the AcomA. So 2 mg nimodipine was infused through the stent delivery microcatheter to the AcomA and the stent delivery microcatheter was passed through the AcomA easily and could be navigated to the ipsilateral A1, ICA, and to the fetal PCA. With this additional stent, the aneurysm was completely separated from the fetal PCA and ICA. Further coiling could be performed safely through the microcatheter in the ipsilateral ICA. The patient had stable aneurysm occlusion at the six-month follow up.

Angiographic results of wide-necked intracranial aneurysms treated with coil embolization : a single center experience

Objective

Endovascular treatment of wide-necked intracranial aneurysms is a challenge and the durability and the safety of these treated aneurysms remain unknown. The aim of this study was to evaluate the clinical and long-term angiographic results of wide-necked intracranial aneurysms treated with coil embolization.

Methods

Between January 2002 and December 2012, 53 wide-necked aneurysms treated with coil embolization were selected. Forty were female, and 13 were male. Twenty eight (52.8%) were ruptured aneurysms, and 25 (47.2%) were unruptured aneurysms. The patents' medical and radiological records were reviewed retrospectively.

Results

Of the 53 aneurysms, coiling alone was employed in 45 (84.9%) and stent-assisted coiling was done in 8 (15.1%). The initial angiographic results revealed Raymond class 1 (complete occlusion) in 30 (56.6%) cases, Raymond class 2 (residual neck) in 18 (34.0%) cases, and Raymond class 3 (residual sac) in 5 (9.4%) cases. The mean angiographic follow-up period was 37.9 months (12-120 months). At the last angiographies, Raymond class 1 was seen in 26 (49.1%) cases, Raymond class 2 in 16 (30.2%), and Raymond class 3 in 11 (20.8%). Angiographic recurrence occurred in 22 (41.5%) patients, with minor recurrence in 7 (13.2%) cases and major recurrence in 15 (28.3%). Retreatment was performed in 8 cases (15.1%). A suboptimal result on the initial angiography was a significant predictor of recurrence in this study (p=0.03).

Conclusion

The predictor of recurrence in wide-necked aneurysms is a suboptimal result on the initial angiography. Long-term angiographic follow-up is recommended in wide-necked aneurysms.

Will Fluoroscopic Follow-up after Stent-Assisted Coiling of Cerebral Aneurysms Provide Information on Recanalization?

Fluoroscopic images for comparison (FICs) can be easily obtained for follow-up on an outpatient basis. This study retrospectively assessed the diagnostic performance of a set of FICs for evaluation of recanalization after stent-assisted coiling, with digital subtraction angiography (DSA) as the reference standard. A total of 124 patients harboring 144 stent-assisted coiled aneurysms were included. At least one month postembolization they underwent follow-up angiograms comprising a routine frontal and lateral DSA and a working-angle DSA. For analysis, FICs should be compared with the mask images of postprocedural DSAs to find recanalization. Instead of FIC acquisition, the mask images of follow-up DSAs were taken as a substitute because of the same view-making processes as FICs, full availability, and perfect coincidence with follow-up DSAs. Two independent readers evaluated a set of 169 FICs and DSA images for the presence of recanalization one month apart. Sensitivity, specificity, and interreader agreement were determined. Recanalization occurred in 24 (14.2%) cases. Of these, nine (5.3%) cases were found to have significant recanalization in need of retreatment. Sensitivity and specificity rates were 79.2% (19 of 24) and 95.9% (139 of 145) respectively for reader 1, and 66.7% (16 of 24) and 97.9% (142 of 145) for reader 2. Minimal recanalization was identified in seven out of all eight false negative cases. Excluding minimally recanalized cases in no need for retreatment from the recanalization group, calculation resulted in high sensitivity and specificity of over 94% for both readers. Interreader agreement between the two readers was excellent (96.4%; κ = 0.84). FICs may be a good imaging modality to detect significant recanalization of stent-assisted coiled aneurysms.

Microcatheter looping facilitates access to both the acutely angled parent artery and cerebral aneurysms for effective embolization

Aneurysms with an acutely angled parent artery are difficult to access for coiling. This study aimed to investigate the safety and effectiveness of microcatheter looping for embolization of cerebral aneurysms with access difficulty. Ten patients (male:female=5:5) with cerebral aneurysms treated with the microcatheter looping technique were analyzed retrospectively. The parent artery formed an acute angle with the major artery in five aneurysms. The microcatheter was looped into a "α" loop for treatment in the anterior temporal artery aneurysm and a "U" loop in the remaining nine aneurysms. All ten aneurysms were successfully treated with the microcatheter looping technique. The microcatheter tip was successfully navigated into the aneurysm sac and remained stable throughout the embolization process. All aneurysms were occluded with total occlusion in five and near-total occlusion in five, and the parent artery remained patent in all cases. No complications occurred peri-procedurally. The Glasgow Outcome Scale was 5 in all patients before discharge. Follow-up angiography six to 12 months later revealed a good occlusion status of the aneurysms. The microcatheter looping technique is effective when the conventional embolization technique fails to treat cerebral aneurysms with difficult access especially when the parent artery forming an acute angle with the major artery exacerbates difficult access to the aneurysms.

Using the snare system to cross the acute-angled vertebrobasilar junction in treating posterior inferior cerebellar artery aneurysm with the stent-assisted method via a retrograde approach. A technical note

Retrograde stenting via the contralateral vertebral artery (VA) is a safe and effective treatment for posterior inferior cerebellar artery (PICA) aneurysm. Many methods, including tip shaping and the looping technique, have been attempted as ways to cross the vertebrobasilar (VB) junction. Here, we introduce an alternative method using a Snare system to overcome the acute-angled VB junction after repeated failures using other techniques. The Snare system was navigated to the proximal basilar artery via the ipsilateral VA. A guidewire was introduced in the contralateral VA and gently advanced to the basilar artery in order to pass through the loop of the Snare system. Following this, the Snare system caught the guidewire and it was very carefully pulled down to the ipsilateral VA crossing the VB junction. We suggest this technique as a method to cross the acute-angled VB junction after failure of all other attempts to overcome this challenge.

Safety and efficacy of target vessel catheterization with the new steerable microcatheter Direxion compared with a standard microcatheter: a prospective, preclinical trial

PURPOSE

To assess the potential of a steerable microcatheter in a comparative preclinical trial.

METHODS

A total of 100 small target vessels of the lower limbs with a maximum diameter of 3 mm were prospectively randomized to catheterize with either the preshaped torqueable Direxion™ (J tip shape; Boston Scientific, Natick, MA) or a similarly steam-shaped Renegade™ microcatheter (Boston Scientific) in a porcine model. Catheterization was first performed in combination with a microguidewire and afterwards without.

RESULTS

No significant differences were found for the mean vessel diameter in the Direxion (1.53 ± 0.44 mm; n = 50) or Renegade (1.62 ± 0.43 mm; n = 50; p = 0.35) group. Guidewire-assisted catheterization was successful in all target vessels, whereas access was achieved in most cases with the guidewire alone. However, when it became necessary to steer the Direxion actively, this was regarded as key to obtain vessel access in three of four target vessels (75 %). Vessel catheterization without guidewire was significantly more successful with the Direxion (88 %; n = 44) compared with the Renegade (32 %; n = 16; p < 0.0001). In addition, this catheterization technique was also significantly faster with the Direxion compared with guidewire-assisted vessel catheterization with the Renegade (16.1 ± 14.4 sec compared with 27.1 ± 24.7 sec; p = 0.011).

CONCLUSIONS

The Direxion microcatheter demonstrated unique steerability characteristics, which makes it a promising new tool especially for complex coaxial endovascular procedures.

The role of endovascular treatment for ruptured distal anterior cerebral artery aneurysms: comparison with microsurgical clipping

BACKGROUND AND PURPOSE

The purpose of this study was to compare clinical outcomes and treatment-related complications between coiling and clipping for ruptured distal anterior cerebral artery (DACA) aneurysms.

METHODS

Eighty-four consecutive patients (M:F = 36:48; mean 53.8 years) with ruptured DACA aneurysms were treated by either clipping (n = 46, 54.8%) or coiling (n = 38, 45.2%). The clinical outcomes and procedure-related complications were evaluated and compared between the two groups.

RESULTS

Procedure-related complications tend to occur more frequently in the clipping (n = 6, 13.0%) than coiling group (n = 1, 2.6%) (P = .121). At discharge, 51 patients (60.7%) had favorable outcomes (Glasgow outcome scale [GOS], 4 or 5). There was no significant difference between the two groups in favorable outcome (63.2% vs. 58.7%; P = .677). Hunt and Hess (HH) grade (P < .001; 95% CI, 3.354-29.609) and treatment modality (P = .044; 95% CI, 1.039-16.325) were independent risk factors for poor outcome (GOS, 1-3).

CONCLUSIONS

Coiling was more favorable to clipping in clinical outcomes and incidence of treatment-related complications for ruptured DACA aneurysms.