Results of the pToWin Study: Using the pCONUS Device for the Treatment of Wide-Neck Intracranial Aneurysms

Endovascular treatment of wide-neck bifurcation aneurysms using pCONUS2 HPC bridging device with single antiplatelet: A Case Series

RATIONALE

Wide neck bifurcation aneurysms (WNBA) are technically challenging for both surgical and endovascular treatments. Endovascular treatment for WNBA often requires dual antiplatelet therapy (DAPT) post stent insertion. Novel devices such as the pCONUS2 HPC neck bridging device have an HPC coating which reduces the device thrombogenicity. This theoretically allows for use of single antiplatelet therapy (SAPT), which would be advantageous, particularly in treating ruptured aneurysms. This case series aims to evaluate the safety of SAPT regimen only post stent insertion, by presenting our center early clinical experience in using pCONUS2 HPC neck bridging device in patients that are not suitable for DAPT.

PATIENT CONCERNS

We report the cases of 3 patients (2 females, 1 male; range: 64-71 years old) who underwent coil embolization for WNBA using the pCONUS2 HPC device (2 unruptured WNBA, and 1 ruptured WNBA). As all 3 patients were allergic to Aspirin, they could only be started on SAPT post endovascular therapy.

DIAGNOSIS

All 3 patients were diagnosed with WNBA on angiographic studies. Patient 1 had an unruptured left middle cerebral artery aneurysm; Patient 2 had a ruptured basilar tip aneurysm; Patient 3 had an unruptured anterior communicating artery (ACOM) aneurysm.

INTERVENTIONS

All 3 WNBA were treated with pCONUS2 HPC neck bridging device.

OUTCOMES

There were no immediate complications. The immediate angiographic result of aneurysm treatment in Patient 1 and Patient 2 demonstrated incomplete occlusions, with delayed complete occlusion of aneurysm in Patient 1 and growth of aneurysmal neck in Patient 2 on follow-up angiograms (range: 6-9 months). No major thrombo-embolic or hemorrhagic complications in the first 2 patients. For Patient 3, the immediate angiographic result of the treated aneurysm demonstrated complete occlusion. However, the patient readmitted 11 days post procedure with cerebral infarction, scoring 5 on the modified Rankin scale on discharge.

LESSONS

pCONUS2 HPC as a neck bridging device in treating WNBA has yet to be shown superior to traditional techniques and devices. The theoretical advantage of HPC coating reducing its thrombogenicity requiring only SAPT is yet to be proven safe in clinical practice.

Endovascular treatment of middle cerebral artery aneurysms: current status and future prospects

Middle cerebral artery (MCA) aneurysms are complex and widely distributed throughout the course of the MCA. Various types of aneurysms can occur in the MCA. Ruptured as well as unruptured MCA aneurysms may require treatment to avoid bleeding or rebleeding. Currently, clipping is regarded as the first-line choice for the treatment of MCA aneurysms. However, endovascular treatment (EVT) is emerging as an alternative treatment in selected cases. EVT techniques vary. Therefore, it is necessary to review EVT for MCA aneurysms. In this review, the following issues were discussed: MCA anatomy and anomalies, classifications of MCA aneurysms, the natural history of MCA aneurysms, EVT status and principle, deployments of traditional coiling techniques and flow diverters (FDs), and deployments and prospects of intrasaccular flow disruptors and stent-like devices. According to the review and our experience, traditional coiling EVT is still the preferred therapy for most MCA aneurysms. FD deployment can be used in selective MCA aneurysms. Parent artery occlusion (PAO) can be used to treat distal MCA aneurysms. In addition, new devices can be used to treat MCA aneurysms, such as intrasaccular flow disruptors and stent-like devices. In general, EVT is gaining popularity as an alternative treatment option; however, there is still a lack of evidence regarding EVT, and longer-term data are not currently available for most EVT devices.

Outcomes Associated With Intracranial Aneurysm Treatments Reported as Safe, Effective, or Durable: A Systematic Review and Meta-Analysis

Importance

Testing new medical devices or procedures in terms of safety, effectiveness, and durability should follow the strictest methodological rigor before implementation.

Objectives

To review and analyze studies investigating devices and procedures used in intracranial aneurysm (IA) treatment for methods and completeness of reporting and to compare the results of studies with positive, uncertain, and negative conclusions.

Data Sources

Embase, MEDLINE, Web of Science, and The Cochrane Central Register of Clinical Trials were searched for studies on IA treatment published between January 1, 1995, and the October 1, 2022. Grey literature was retrieved from Google Scholar.

Study Selection

All studies making any kind of claims of safety, effectiveness, or durability in the field of IA treatment were included.

Data Extraction and Synthesis

Using a predefined data dictionary and analysis plan, variables ranging from patient and aneurysm characteristics to the results of treatment were extracted, as were details pertaining to study methods and completeness of reporting. Extraction was performed by 10 independent reviewers. A blinded academic neuro-linguist without involvement in IA research evaluated the conclusion of each study as either positive, uncertain, or negative. The study followed Preferring Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Main Outcomes and Measures

The incidence of domain-specific outcomes between studies with positive, uncertain, or negative conclusions regarding safety, effectiveness, or durability were compared. The number of studies that provided a definition of safety, effectiveness, or durability and the incidence of incomplete reporting of domain-specific outcomes were evaluated.

Results

Overall, 12 954 studies were screened, and 1356 studies were included, comprising a total of 410 993 treated patients. There was no difference in the proportion of patients with poor outcome or in-hospital mortality between studies claiming a technique was safe, uncertain, or not safe. Similarly, there was no difference in the proportion of IAs completely occluded at last follow-up between studies claiming a technique was effective, uncertain, or noneffective. Less than 2% of studies provided any definition of safety, effectiveness, or durability, and only 1 of the 1356 studies provided a threshold under which the technique would be considered unsafe. Incomplete reporting was found in 546 reports (40%).

Conclusions and Relevance

In this systematic review and meta-analysis of IA treatment literature, studies claiming safety, effectiveness, or durability of IA treatment had methodological flaws and incomplete reporting of relevant outcomes supporting these claims.

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.

pCONUS 2 and pCONUS 2-HPC in the treatment of wide-necked intracranial aneurysms: Multicentre UK experience

BACKGROUND/PURPOSE

pCONUS 2 and pCONUS 2-HPC are neck-bridging devices that provide coiling support in the endovascular treatment of wide-necked intracranial aneurysms. To date, limited multicentre data has been published. This study provides the first pooled data from multiple UK centres regarding outcomes for these devices covering the periprocedural period to 6-month follow-up.

MATERIALS/METHODS

This retrospective, single-arm study assessed 65 patients treated over 3 years from the time of procedure to 6 months post-procedure across four UK centres. Data collected included patient demographics, aneurysm characteristics and antiplatelet regimens. Outcome measures were angiographic results and procedure-related complications from the immediate periprocedural period to 6-month follow-up.

RESULTS

Fifty-four unruptured (83.1%) and 11 ruptured (16.9%) aneurysms were treated. Fifty-five aneurysms were located in the anterior circulation (87.7%). There were four device-related intraprocedural complications: three cases of asymptomatic, temporary thrombus formation and one mortality associated with branch vessel occlusion and aneurysm re-bleeding in a ruptured case. There were no post-procedural device-related complications. Satisfactory occlusion was achieved in 58/65 procedures (89.2%) at time of treatment and in 44/60 (73.3%) at 6 months. Satisfactory occlusion correlated with aneurysm size and coiling packing density. Retreatment was required for five unruptured cases (7.7%) and was straightforward with the device in situ.

CONCLUSION

pCONUS 2 and pCONUS 2-HPC have good short-term safety profiles. The use of pCONUS 2-HPC in the acute treatment of ruptured aneurysms with postprocedural SAPT is feasible. The devices have an intraprocedural complication rate of 4/65 (6.2%) across multiple UK centres, including a single death (1.5%).

[pConus device for endovascular treatment of basilar bifurcation aneurysms]

Aneurysm occlusion with microcoils is an effective and safe procedure. However, bifurcation aneurysms usually have a wide neck, and their occlusion is still a difficult objective.

OBJECTIVE

To evaluate the efficacy and safety of bifurcation stents in the treatment of basilar bifurcation aneurysms.

MATERIAL AND METHODS

A retrospective analysis included 34 patients with basilar bifurcation aneurysms between 2016 and 2022. The pConus bifurcation stent was used as a stent-assistance for endovascular occlusion of aneurysms with microcoils. We analyzed technical features of stent implantation and clinical results of endovascular treatment. Mean aneurysm dimension was 8.4 mm, neck size - 4.6 mm. Preoperative MSR score 0-2 was observed in 94.7% of patients, 3-5 scores - in 5.3% of patients.

RESULTS

There were no significant changes in functional status early after surgery (MSR grading system). Total aneurysm occlusion was achieved in 67.6% of patients, subtotal - 17.6% of cases, partial - 14.8%. There were no technical or early postoperative clinical complications. Six months after surgery, total occlusion was observed in 77.8% of patients, subtotal occlusion - 14.8%, partial occlusion - 4%. MSR score 0-2 was observed between 3 and 12 months after surgery. One patient died from other cause rather aneurysm. Redo intervention due to aneurysm recanalization was performed in 1 patient.

CONCLUSION

The pConus bifurcation stent is effective and safe in endovascular treatment of basilar bifurcation aneurysms of the most complex configuration. There was a minimal risk of aneurysm recanalization in long-term postoperative period.

Treatment of unruptured middle cerebral artery aneurysms: Systematic review in an attempt to perform a network meta-analysis

Objective

Open surgical clipping has been generally considered the best treatment option for unruptured middle cerebral artery aneurysms (uMCAAs). However, this type of aneurysm is being treated endovascularly with the appearance of new devices. We have carried out a systematic review of randomized and quasi-experimental studies to conduct a network meta-analysis (NMA) to assess the safety and efficacy of the different treatment methods currently used in uMCAAs.

Methods

The literature was searched by using PubMed and Google Scholar databases. Eligibility criteria were randomized or quasi-experimental studies including at least five cases per arm and reporting duration of follow-up and number of lost cases. The end points were: angiographic success, final neurological outcome, and the need for retreatments.

Results

We could only analyze four quasi-experimental studies with 398 uMCAAs. All of them compared clipping vs. coiling. Clipping showed better results than coiling in all analyzed end points. We could not conduct the proposed NMA because of the absence of randomized or quasi-experimental studies. Instead, a systematic review is further discussed.

Conclusions

There is an urgent need for comparative studies on the treatment of uMCAAs.