Diffusion-weighted imaging lesions after intracranial aneurysm treatment with Pipeline Flex and Pipeline Flex with Shield technology: a retrospective cohort analysis

BACKGROUND

The Pipeline Flex embolization device with Shield technology (PED Shield) is the first flow diverter for brain aneurysm treatment approved in the United States using surface-modified technology. The effect of PED Shield on decreasing perioperative diffusion-weighted imaging positive (DWI+) hits, as a marker for in-human decrease thrombogenicity, is unclear.

OBJECTIVE

To determine if the number of periprocedural DWI+ lesions differs between patients with an aneurysm treated with PED Flex and PED Shield.

METHODS

This retrospective study compares the outcomes of consecutive patients with an aneurysm treated with PED Flex and PED Shield. The primary outcome of interest was the occurrence of DWI+ lesions. We also assessed potential predictors of DWI+ lesions and compared the outcomes between on-label and off-label treatment indications.

RESULTS

89 patients were included, 48 (54%) treated with PED Flex and 41 (46%) with PED Shield. After matching, the incidence of DWI+ lesions was 61% and 62% for the PED Flex and PED Shield groups, respectively. Results were consistent across each model with no significant differences in DWI+ lesions between treatment groups, and effect sizes ranging from OR=1.08 (95% CI 0.41 to 2.89) after propensity score matching to OR=1.84 (95% CI 0.65 to 5.47) after multivariable regression. Multivariable models demonstrated reduced DWI+ lesions with balloon-assisted therapies and posterior circulation treatment, while a significant linear relationship was encountered with fluoroscopy time.

CONCLUSION

There was no significant difference in the incidence of perioperative DWI+ lesions between patients with an aneurysm treated with PED Flex and PED Shield. Larger cohorts are likely needed to demonstrate differences between the devices.

Heavily Calcified Symptomatic Carotid Stenosis Treated With Off-Label Use of Lithotripsy Balloon Plus Stenting: 2-Dimensional Operative Video

Severe symptomatic carotid artery stenosis poses a significant risk for recurrent strokes. Best treatment options depend on multiple factors, including patient medical conditions and lesion characteristics.1 Despite treatment options such as carotid endarterectomy, conventional carotid angioplasty/stent, and transcervical carotid revascularization, certain patients are not ideal candidates for any of these modalities. Novel technical advances such as intravascular lithotripsy (Shockwave Medical Inc.) have emerged as a potential treatment modality to treat patients with severely calcified plaques, a well-described limitation for carotid stent expansion and apposition.2-4 The safety and efficacy of intravascular lithotripsy have been demonstrated through select case series and coronary artery disease I-II-III studies, culminating in its Food and Drug Administration approval for the management of novo, calcified, stenotic coronary arteries before stent placement.2,5 This technical video presents an illustrative case of a patient with symptomatic severely calcified carotid plaque with previous neck radiation precluding endarterectomy, treated with off-label use of balloon lithotripsy plus stent.6 The patient consented to the procedure.

Patient outcomes after treatment of brain aneurysm in small diameter vessels with the silk vista baby flow diverter: A systematic review

BACKGROUND

The Silk Vista Baby (SVB, BALT) is a first-in-class flow-diverter device delivered using a 0.017" microcatheter, designed for the treatment of intracranial aneurysms, including those in small diameter vessels. This study reports a systematic literature review (SLR) to evaluate the safety and efficacy of using SVB to treat intracranial aneurysms in vessels less than 3.5 mm in diameter.

METHODS

We performed a PRISMA-compliant SLR to evaluate the outcomes of SVB in the treatment of aneurysms in small intracranial vessels. Primary outcomes were occlusion status and major stroke, and secondary outcomes included all-cause mortality, procedure-related neurologic death, and post-operative aneurysm rupture. Data were expressed as descriptive statistics only.

RESULTS

A total of four studies, including 163 patients with 173 intracranial aneurysms, were included. The most common aneurysm locations were the anterior cerebral artery (24.9% [43/173]), the middle cerebral artery (24.3% [42/173]), and the anterior communicating artery (23.1% [40/173]). Parent artery diameter ranged from 0.9 mm to 3.6 mm, and 29% were acutely or previously ruptured aneurysms. Overall, complete or near-complete occlusion was 72.1% on early-term follow-up. Mortality rate among the studies was 2.5%, with 3 instances adjudicated as neurologic deaths (1.8%). Major stroke was noted in 1.2% of cases, and branch occlusion or stent thrombus formation in 5.5%.

CONCLUSION

Our review suggests that SVB is a safe and effective treatment for intracranial aneurysms in small vessels. Further prospective and comparative studies with patient outcome data specific to aneurysm location are needed to confirm the safety and efficacy of SVB.

Surgical salvage for recurrent vestibular schwannoma after primary stereotactic radiosurgery

Background

The management of vestibular schwannoma has evolved over the past hundred years. In the last decades, surgery has been gradually replaced by radiation therapy as a primary treatment modality, particularly for small tumors, due to the less invasive nature and the compared reported outcomes in tumor control and hearing preservation. However, irradiation sometimes fails to stop tumor growth. In a long-term follow-up after primary fractionated stereotactic radiotherapy, the rate of treatment failure was reported as 3% and needed surgical salvage. For single-fraction modality, Hasegawa et al. reported salvage treatment after primary Gamma Knife radiosurgery in 8%, where 90% of these underwent surgery and 50% of those who were treated with a second gamma knife surgery required surgical intervention later. An increase in tumor volume by more than 10-20%, tumor growth after three years, and no return to pretreatment volume after transient swelling have been considered as tumor recurrence rather than pseudoprogression, a transient increase in tumor volume after radiotherapy that occurs up to 30% of cases. It has been reported that microsurgery after radiotherapy is more difficult, with most authors reporting a loss of defined arachnoid planes and worse cranial nerve outcomes, especially for hearing and facial nerve function.

Case Description

A 43-year-old female patient was incidentally (asymptomatic) diagnosed on a magnetic resonance imaging (MRI) scan harboring a left vestibular schwannoma, grade T2 (Hannover classification), in 2015. Neurologic examination was unremarkable, and audiometry testing was normal. She was initially treated with observation. Three years later, in 2018, the lesion had enlarged, becoming a grade T3a and reaching the cistern of the cerebellopontine angle. The tumor was then treated with fractionated stereotactic radiosurgery (5 sessions of 5 Gy). MRI scans in 2019 and 2020 showed slight tumor growth. This enlargement was attributed to a pseudoprogression after radiosurgery, and only observation was advocated. In 2022, 4 years later, after radiosurgery, the tumor was still growing, and the patient began to suffer from hearing loss. A failure treatment was considered, and microsurgery was indicated. The patient was counseled about the risk of functional nerve impairment, and surgical consent was obtained. A retro sigmoid approach was planned. A gross total resection was attempted due to the clear subperineural plane during tumor dissection and because it was the only option that would provide a cure for the patient. The adjacent neurovascular structures were firmly adhered to the tumor capsule, which represented a major challenge for microdissection. The tumor was soft, without significant bleeding. A total resection was achieved, and the facial nerve was anatomically preserved. The patient developed facial paresis (House-Brackmann III) in the immediate postoperative period, which improved at the 6-month follow-up. Hearing loss did not improve. Postoperative MRI showed total resection.

Conclusion

Microsurgery after radiotherapy for vestibular schwannoma is challenging in terms of indication, when to indicate, resection target, difficulty in dissection due to local changes, and outcome. Gross total resection may be considered, as it is the only treatment that may provide a cure for the patient. However, the patient should be counseled about the risks.

Safety and Efficacy of Flow Diverters for Treatment of Unruptured Anterior Communicating Artery Aneurysms: Retrospective Multicenter Study

BACKGROUND

The anterior communicating artery (AComm) region is the most common site of intracranial aneurysms, with increased rupture risk compared with other locations. Overall, flow diverters present as a safe and efficacious treatment for intracranial aneurysms, but there is paucity of data for their use in the treatment of unruptured AComm aneurysms. We present the largest multicentric analysis evaluating the outcomes of flow diverters in AComm aneurysm treatment.

METHODS

Databases from 10 centers were retrospectively reviewed for unruptured AComm aneurysms treated with flow diverters. Demographics, clinical presentation, radiographic characteristics, procedural complications, and outcomes were assessed.

RESULTS

A total of 144 patients harboring 147 AComm aneurysms were treated between January 2012 and December 2021. Seventy-four were women (51.4%) and median age was 60 (IQR 50-67) years. All were unruptured AComm aneurysms. Half of the cohort had similar anterior cerebral artery sizes (51.4%). The most common morphology was saccular (94.6%), with a branch involvement in 32.7% of cases. Median vessel diameter was 2.4 mm, and the Pipeline Flex was the most prevalent device (32.7%). Median follow-up time was 17 months, with complete occlusion in 86.4% at the last follow-up. Functional independence (modified Rankin Scale score 0-2) was reported in 95.1%. Intraprocedural complications occurred in 5.6%, and postoperative complications were noted in 9.7% of cases. Combined major complication and mortality rate was 2.1%.

CONCLUSIONS

Our study suggests that flow diverters are a useful treatment for AComm aneurysms. Mid-term results indicated favorable aneurysm occlusion with a good safety profile. Additional prospective studies with longer follow-up periods and independent adjudication are warranted to better assess these results.

Tenzing 7 delivery catheter with or without a leading microwire for single pass aspiration thrombectomy: A multicenter experience

INTRODUCTION

Aspiration mechanical thrombectomy traditionally includes use of an inner microcatheter and leading microwire to navigate an aspiration catheter (AC) to the site of occlusion. Early clinical experience suggests that a leading microwire is often not needed with the Tenzing 7 (T7, Route 92 Medical, San Mateo, CA), a soft tapered tip ledge-reducing delivery catheter. This multicenter experience aims to describe AC delivery success in single-pass thrombectomy using T7 with and without a leading microwire.

METHODS

A retrospective review was conducted of consecutive patients who underwent single-pass thrombectomy with T7 at six institutions between 2020 and 2022. We examined the percentage of successful AC delivery, puncture-to-revascularization time, and procedural complication rate.

RESULTS

A leading microwire with T7 was used in 19/89 (21%) of patients, and it was not used with T7 in 70/89 (79%) of patients. Successful AC delivery was similar with and without microwires (97% vs. 90%, p = 0.15). Median puncture-to-revascularization times were similar (17 min microwire vs. 16 min no-microwire, p = 0.12). No complications were associated with microwire use; one (1.4%) patient had a T7-related vasospasm resolved with verapamil during thrombectomy without a leading microwire. Differences in complication rates were not statistically significant (p = 0.46).

CONCLUSION

In our real-world clinical experience, leading microwire use was infrequently necessary with the T7 delivery catheter. Successful AC delivery and complication rates were similar with and without microwire use in single-pass T7 thrombectomies. Initial pass with T7 may be performed without use of leading microwire, reserving microwire use for refractory cases or known difficult-to-navigate vasculature.

Silk Vista Baby for the Treatment of Complex Posterior Inferior Cerebellar Artery Aneurysms

BACKGROUND

Treatment of small-caliber vessel lesions using flow diverters remains challenging because of vasculature's narrow luminal diameter and tortuosity. This in turn makes navigation and delivery of conventional devices with standard microcatheters more difficult. The Silk Vista Baby (SVB, Balt) flow diversion device was designed for ease of use in vessels with a smaller diameter, distal lesions, and 0.017 ″ microcatheter delivery systems.

OBJECTIVE

To report the outcomes of the SVB device on the treatment of posterior inferior cerebellar artery (PICA) aneurysms.

METHODS

Databases from different centers were retrospectively reviewed for PICA aneurysms treated with SVB. Demographic information, clinical presentation, radiographic characteristics, procedural complications, and immediate postprocedure outcomes were obtained.

RESULTS

Fourteen patients harboring 15 true PICA aneurysms were treated between January 2019 and June 2021. Nine were female (n = 9/14; 64.2%), and the mean age was 51 ± 14.9 years. Most patients had previously ruptured aneurysms, treated by another endovascular technique. Six aneurysms were located distally (n = 6/15; 40%). The mean neck size was 3 mm (SD 1.35, range 2.5-5 mm), whereas the mean PICA diameter was 1.6 mm (SD 0.26, range 1.5-1.7 mm). The mean length of follow-up was 6 months (SD 8.28, range 4.5-16 months). Treatment-related adverse events included 1 case of transient hypoesthesia. Two additional events were reported, but adjudicated as unrelated to the procedure. Complete occlusion, measured as Raymond-Roy class I, was achieved in all cases.

CONCLUSION

The SVB device was safely and effectively used in the treatment of PICA aneurysms. The smaller delivery system profile reduces the risk of procedure complications and creates new treatment options for distal lesions.