The goal of this prospective, observational study is to evaluate the long-term occlusion rates and safety of the Penumbra PC400 coil in the treatment of ruptured and unruptured intracranial aneurysms in adult subjects ages 18-80.

Specifically, the study aims to analyze rate of death, stroke, neurological death, or rebleeding associated with the treatment of intracranial aneurysm with the PC400 coil.

Participants will undergo standard of care treatment and follow up for their aneurysm treatment, and participating sites will collect procedural and follow up data.

Endovascular treatment has become the primary approach for intracranial aneurysms, offering improved safety and reduced recanalization rates. Despite advancements in flow diversion and intrasaccular devices, coiling remains a cornerstone therapy. However, aneurysmal recurrence due to regrowth or coil compaction continues to be a significant concern, with recurrence observed in about 20% of cases, leading to potential rebleeding and treatment challenges.

The Penumbra PC400 coil (Penumbra Inc., Alameda, CA, USA) addresses these concerns by offering 400% more volume per unit length than traditional 0.010-inch coils. This design also reduces procedure and fluoroscopy times, improving overall efficiency. Several retrospective reports have highlighted its advantages in packing density, procedure time, and cost-effectiveness.1,2,3 However, there is a lack of high-level prospective data to support these findings.

The goal of the present study is to determine occlusion rates and safety when Penumbra PC400 coils are used in the treatment of ruptured or unruptured medium and large sized (5mm or more) intracranial aneurysms.

Up to 100 patients ≥ 18 and ≤ 80 years presenting with ruptured or unruptured saccular aneurysms who meet all eligibility criteria will be enrolled. Enrolled subjects must be treated with Penumbra PC400 coils used in any combination comprising a minimum of 80% total coil length used.

The primary safety endpoint is procedure- or disease-related death or major stroke within 30 days of treatment or major ipsilateral stroke, neurological death or rebleeding from the target aneurysm during the 18-month follow-up period. The primary efficacy endpoint is Adequate angiographic occlusion at 18 ± 6 months without interim retreatment secondary to aneurysm recurrence or rebleed of the target aneurysm. This will be assessed by an imaging core lab using digital subtraction angiograms (DSA).

Secondary endpoints include Clinical outcome (mRS) at 30 days, clinical outcome (mRS) at 18 months, packing density as measured by volumetric filling of the aneurysm immediately post-procedure, mean number of coils, procedural duration (in minutes), retreatment rate due to recurrence at 18 months, adequate angiographic occlusion at 18 without rebleed of the target aneurysm, occlusion stability at 18 months, peri-/post-procedural adverse events related to the device and/or the procedure.

Data will be shared with the coordinating center, Semmes Murphey Foundation, via a secure electronic database, REDCap. Access to the REDCap database will only be granted to IRB approved research personnel from participating sites. Subjects will be given a subject ID in the database. Throughout the data collection period, investigators may maintain a linking key that links the subject to their ID. This linking key will only be accessible to the investigator and site personnel. Once data collection has been completed, the linking key will be erased so that there will be no way to re-link subjects with their research data. Research data from each site will only be accessible to the approved research personnel at that site; authorized research personnel from the coordinating center will only have access to the coded data in the REDCap database for each site for study monitoring purposes. No patient contact will occur outside of standard of care procedures. Participating sites will execute a Data Use Agreement (DUA) with the coordinating center.

Inclusion Criteria:

• Subject is ≥ 18 and ≤ 80 years of age.
• Subject has a previously untreated, ruptured or unruptured, saccular intracranial aneurysm 5mm or more in diameter for which the clinical decision to treat with Penumbra PC400 embolization coils has been made independent of the decision to enroll the subject in the study described in this protocol.
• The decision to undergo the coiling procedure is made independently of and prior to participation in the research.
• Subject has a baseline Hunt and Hess Score of I, II, or III.
• Subject must be considered by the treating physician to be available for and able to complete all follow-up visits.
• Subject has not been previously entered into this study.

Exclusion Criteria:

• Subject is < 18 or > 80 years of age.
• Subject has a baseline Hunt and Hess score of IV or V.
• Target aneurysm is dissecting, fusiform, blister-like, mycotic, tumoral, or AVM related.
• Target aneurysm maximum diameter is <5mm
• Target aneurysm was previously treated via clipping or coiling.
• Target aneurysm is deemed by the treating physician to be unsuitable for coiling or unlikely to be successfully treated by endovascular techniques.
• Target aneurysm has not been confidently determined by the treating physician to be the source of SAH.
• Planned use of a flow diverter (Surpass, Pipeline, Silk, FRED, p64, etc.) or intrasaccular device (WEB, Artis, Medina, etc.) as a component of the target aneurysm treatment plan.
• Intended use of a coil-assist stent as a component of the target aneurysm treatment plan, unless stent is used for bailout purposes.
• Subject has a known, untreatable hypersensitivity to contrast dye, iodine, hydrogel, or any other component of the treatment device.
• Subject has a contraindication to heparin or aspirin.
• Subject has vascular anatomy/tortuosity preventing access to the target aneurysm.
• Subject is unable to undergo DSA or DSA is determined unsuitable or outside standard of care by the treating physician.
• Subject has a serious or life-threatening comorbidity that could confound study results.
• Subject is at high risk of noncompliance due to a history of substance abuse, psychosocial issues, etc.
• Subject is unable to complete scheduled follow-up assessments due to comorbidities, geographical limitations, or a life expectancy of less than 18 months.
• Subject is pregnant, breastfeeding, or plans to become pregnant prior to completion of follow-up.
• Subject is enrolled in another device or drug study in which participation could confound study results.

All eligible subjects presenting to a participating study site will be considered for enrollment. Up to 100 patients ≥ 18 and ≤ 80 years presenting with ruptured or unruptured saccular aneurysms who meet all eligibility criteria will be enrolled. Enrolled subjects must be treated with Penumbra PC400 coils used in any combination comprising a minimum of 80% total coil length used.

IPD to be shared will include all IPD that underlie results of the publication.

The IPD will be available following study completion estimated to be in 2029 with no set end date.

A designated biostatistician will access study IPD. Access will be established through secure electronic transfer. Following publication, results and supporting information will be established on the ClinicalTrials.gov website.