Evaluation of an in vivo preclinical model for human middle meningeal artery embolization using the posterior intercostal artery of the swine

BACKGROUND

Embolization of the middle meningeal artery (MMA) is a promising minimally invasive technique that is gaining traction in the treatment of chronic subdural hematoma. Unfortunately, the human meninges and associated arteries are significantly larger than those of conventional laboratory animals, making the development of a clinically relevant animal model for testing of embolization agents elusive.

OBJECTIVE

To introduce the posterior intercostal artery (PIA) model in swine and provide anatomical, angiographic, histological, and procedural data to validate its relevance in modeling the human MMA.

METHODS

In human cadaveric specimens, 3D angiograms of the internal maxillary arteries (n=6) were obtained and the dura with MMA were harvested and histologically processed. Angiographic and histologic data of the human MMA were compared with the swine PIA (three animals). Then, embolization of the PIA (n=48 arteries) was conducted with liquid embolization agent (Onyx, Medtronic), and angiographic and histological results were assessed acutely (four animals) and after 30 days (two animals).

RESULTS

The human MMA has equivalent diameter, length, branching pattern, 3D trajectory, and wall structure to those of swine PIAs. Each swine has 12 to 14 PIAs (6-7 per side) suitable for acute or chronic embolization, which can be performed with high fidelity using the same devices, agents, and techniques currently used to embolize the MMA. The arterial wall structure and the acute and chronic histological findings in PIAs after embolization are comparable to those of humans.

CONCLUSIONS

This PIA model in swine could be used for research and development; objective benchmarking of agents, devices, and techniques; and in the training of neurointerventionalists.

The pCONUS2 and pCONUS2 HPC Neck Bridging Devices : Results from an International Multicenter Retrospective Study

INTRODUCTION

Bifurcation aneurysms represent an ongoing endovascular challenge with a variety of techniques and devices designed to address them. We present our multicenter series of the pCONUS2 and pCONUS2 HPC devices when treating bifurcation aneurysms.

METHODS

We performed a retrospective review of our prospectively maintained databases at 3 tertiary neurointerventional centers to identify all patients who underwent coil embolization with the pCONUS2 or pCONUS2 HPC device between February 2015 and August 2021. We recorded baseline demographics, aneurysm data, complications, immediate and delayed angiographic results.

RESULTS

We identified 55 patients with 56 aneurysms, median age 63 years (range 42-78 years), 67.3% female (n = 37). The commonest aneurysm location was the MCA bifurcation (n = 40, 71.4%). Average dome height was 8.9 ± 4.2 mm (range 3.2-21.5 mm), average neck width 6.4 ± 2.5 mm (range 2.6-14 mm), and average aspect ratio 1.3 ± 0.6 (range 0.5-3.3). The pCONUS2 was used in 64.3% and the pCONUS2 HPC in 35.7%. The procedural technical success rate was 98.2%. Intraoperative complications occurred in 5 cases (8.9%), 4 of which were related to the coils with partial thrombus formation on the pCONUS2 HPC seen in 1 case that was resolved with heparin. In relation to the procedure and treatment of the aneurysm the overall permanent morbidity was 1.8% (n = 1/55) and mortality 0%. Delayed angiographic follow-up (48 aneurysms) at median 12 months postprocedure (range 3-36 months) demonstrated adequate occlusion of 83.4% of aneurysms.

CONCLUSION

The pCONUS2 and pCONUS2 HPC devices carry a high technical success rate, low complication and retreatment rate, and good rates of adequate occlusion. Larger prospective confirmatory studies are required.

[Impact of artificial intelligence on therapeutic metrics of cerebrovascular attack during the COVID-19 pandemic]

INTRODUCTION

The start of the COVID-19 pandemic forced the implementation of changes in the emergency services care system. Concomitantly, at our institution, we implemented the artificial intelligence (AI) software, RAPID.AI, for image analysis in ischemic stroke (IS). Our objective was to evaluate the impact of the use of AI together with the changes in the triage during the COVID-19 pandemic in patients with stroke due to large vessel occlusion (LVO).

METHODS

We included patients with IS due to LVO treated with intravenous reperfusion therapy plus endovascular or direct endovascular therapy.

RESULTS

Two groups were created. Group 1: patients from January 2019 to June 2020; Group 2: patients from July 2020 to December 2021, studied with RAPID.AI. Clinical data and temporal metrics were analyzed. They were compared according to arrival time from 08:00 to 20:00 (daytime) vs 20:01 to 7:59 (night).

RESULTS

We included 286 patients, 153 in group 1 and 133 in group 2. In group 2, door-image metric and image duration were lower, with shorter door-image onset and door-recanalization times; patients who arrived at night had higher NIHSS and longer time from onset-to-door with lower proportion of functional independence at 90 days (mRS = 2).

CONCLUSIONS

The use of AI for image analysis along with a shorter door to end of image time allowed to reduce the interval to groin puncture. In the analysis by hours during the pandemic, patients admitted in daytime hours had significantly lower door to image, image time acquisition, and door to recanalization metrics.

Abstract TMP3: Long-term Outcomes From The Pipeline Embolization Devices For The Treatment Of Intracranial Aneurysms (PEDESTRIAN) Registry With Ped Shield Sub-analysis

Background: Prospective studies have established the safety and efficacy of the Pipeline TM Embolization Device (PED) for treatment of intracranial aneurysms (IA).

Objective: To investigate long-term outcomes from the Pipeline Embolization Devices for the Treatment of Intracranial Aneurysms (PEDESTRIAN) Registry.

Methods: The PEDESTRIAN registry data was retrospectively reviewed, which included patients (March 2006-July2019) with complex IAs treated with PED. The primary angiographic endpoint was complete occlusion and long-term stability. Clinical and radiological follow-up was performed at 3-6 months, 12 months, and yearly thereafter.

Results: A total of 835 patients (mean age 55.9±14.7 years; 80.0% female) with 1,000 aneurysms were included. Aneurysms varied in size: 64.6% were small (≤10mm), 25.6% were large (11-24mm), and 9.8% were giant (≥25mm). A total of 1,214 PEDs were deployed. Follow-up angiography was available for 85.1% of patients with 776 aneurysms at 24.6±25.0 months (mean). Complete occlusion was demonstrated in 75.8% of aneurysms at 12-months, 92.9% at 2-4 years, and 96.4% at >5 years. During the post-procedural period, mRS remained stable or improved in 96.2% of patients, with stability or improvement in 99.1% of patients >5 years. The overall major morbidity and neurological mortality rate was 5.8%. At multivariate analysis, age (HR 1.04; 95% CI 1.01-1.07, p=0.002) and non-saccular morphology (HR 2.91; 95% CI 1.06-7.97, p=0.038) were identified as independent predictors of mRs worsening. We found a trend towards lower rates of thromboembolic complications since the implementation of prasugrel, with 26 (4.4%) patients on clopidogrel developing stroke compared with 4 (1.6%) patients on prasugrel (OR 2.74; 95% CI 0.95-7.95, p=0.06). Trend towards less thromboembolic complications with PED Shield N= 3/213 (1,4%) OR 0.38 (95% CI o.12; 1.27), p value=0.11

Conclusion: This study demonstrated high rates of long-term complete aneurysm occlusion, stable or improved functional outcomes, and low rates of complications and mortality. Clinical and angiographic outcomes improved over long-term follow-up, demonstrating endovascular treatment of IA with PED is safe and effective.

Ophthalmic artery angioplasty for age-related macular degeneration

BACKGROUND

There is considerable overlap of contributors to cardiovascular disease and the development of age-related macular degeneration (AMD). Compromised ocular microcirculation due to aging and vascular disease contribute to retinal dysfunction and vision loss. Decreased choroidal perfusion is evident in eyes with dry AMD and is thought to play a role in retinal pigment epithelial dysfunction, the rate of development of geographic atrophy, and the development of neovascularization. The aim of the study was to demonstrate that AMD is correlated with a compromised blood flow in the ocular pathway and show OA angioplasty as a potential treatment of late-stage AMD.

METHODS

Based on the potential for the ophthalmic artery (OA) to be an anatomical target for the treatment of AMD as outlined above, five patients were found to be eligible for compassionate use treatment, presenting clinically significant late-stage AMD with profound vision loss in one or both eyes, and are included in this retrospective study.

RESULTS

OA narrowing, or significant calcium burden at the ophthalmic segment of the internal carotid artery compromising the origin of the OA was confirmed in all cases. Subsequent OA cannulation was achieved in all patients with some difficulty. Subjective patient reports indicated that all patients perceived a benefit following the procedure; however, improved postoperative visual acuity did not confirm that perceived benefit for one of the patients.

CONCLUSIONS

Feasibility and safety of the OA angioplasty were demonstrated, and a benefit perceived in five patients with profound vision loss and a desire to achieve improved quality of life. A clinical trial with controlled schedule, imaging, and methodologies is needed to confirm these results.

Abstract MP8: Long Term Angiographic and Clinical Outcomes From 1,000 Aneurysms Treated With the Pipeline Embolization Device

Background and Purpose: Prospective studies have established the safety and efficacy of the Pipeline TM Embolization Device (PED) for the treatment of intracranial aneurysms (IA). Here, we report long-term outcomes from The Pipeline Embolization Devices for the Treatment of Intracranial Aneurysms (PEDESTRIAN) Registry.

Methods: This was a retrospective review of prospectively collected data from the PEDESTRIAN registry. Between March 2006 and July 2019, consecutive patients with complex IA were treated with PED at one center in Argentina. Patients with unfavorable anatomy and/or recurrence following previous treatment were included, and those with acute subarachnoid hemorrhage (SAH) were excluded. The primary angiographic endpoint was complete occlusion and long-term stability. Clinical and angiographic follow-up was performed at 3-6 months, 12 months, and yearly thereafter.

Results: A total of 835 patients (mean age 55.9±14.7 years; 80% [671/835] female) with 1,000 aneurysms were included. The majority (64.6%) of aneurysms were small (≤10mm), 25.6% were large (11-24mm), and 9.8% were giant (≥25mm). A total of 1,214 PEDs were deployed, with a single device deployed in 84.2% of aneurysms. Follow-up angiography was available for 85.1% of patients with 776 aneurysms at mean 24.6±25.0 months. Complete Raymond Roy I occlusion was demonstrated in 75.8% (588/776) of aneurysms at 12-months, 92.9% (300/323) at 2-4 years, and 96.4% (159/165) at >5 years. During the post-procedural period, mRS remained stable or improved in 96.2% of patients, with stability or improvement in 99.1% of patients in the longer term. The overall major morbidity and neurological mortality rate was 5.8% (44/835), and the all-cause mortality rate was 4.6% (38/835).

Conclusions: Endovascular treatment of IA with PED is safe and effective, with rates of complete occlusion, complications, and mortality comparable to previous prospective studies. Serial angiographic follow-up showed high and increasing occlusion rates, with stable occlusion of all cases at 13 years.

Phosphorylcholine surface modified flow diverter associated with reduced intimal hyperplasia

Background

Optical coherence tomography (OCT) is a high-resolution, intra-vascular diagnostic technique widely used for the characterization of vascular pathologies and optimization of stent implantation during percutaneous coronary intervention. OCT was used to investigate the in vivo vascular response to a new phosphorylcholine surface modified flow diverter (sPED).

Methods

In an in vivo rabbit aneurysmal model, we used two different types of flow diverters (classic Pipeline – cPED; and sPED) with or without dual antiplatelet therapy (four groups, n=10 per group). OCT cross-sectional area measurements were compared with histology in all animals. Neointimal hyperplasia (NIH) ratio was compared between OCT and histology at five different levels for each stent. The severity of NIH was also compared between the different stents, antiplatelet protocols, and vessel locations.

Results

OCT was used to calculate in-stent hyperplasia in 227 different locations corresponding to histology sections. OCT measurement strongly correlated with gold standard histology (r2=0.83; slope=0.988; P<0.0001). sPED had significantly less in-stent NIH than non-treated flow diverters (mean percent of lumen reduction 5.7% for sPED versus 8.9% for cPED; P<0.0001). The NIH ratio was slightly higher with dual antiplatelet therapy (DAPT) (NIH ratio=7.9% with DAPT versus 6.8% without DAPT; P<0.05). Complete and near complete occlusion rates of the aneurysms were not different with the cPED or sPED.

Conclusion

OCT is a promising technique for immediate and long-term evaluation of flow diverter stent treatments. In an animal model, phosphorylcholine surface modified flow diverters induces less NIH after stent implant without reducing aneurysm occlusion rates.