Comparison of Intracranial Aneurysms Treated by 2-D Versus 3-D Coils: A Matched-Pairs Analysis

TARGET® Intracranial Aneurysm Coiling Prospective Multicenter Registry: Final Analysis of Peri-Procedural and Long-Term Safety and Efficacy Results

Background and Purpose: To describe the final results of the TARGET Registry, a multicenter, real-world study of patients with intracranial aneurysms treated with new generation TARGET Coils.

Methods: The TARGET Registry is a prospective, single-arm study with independent medical event monitoring and core-lab adjudication. Patients with de novo intracranial aneurysms were embolized with either TARGET-360° or helical coils in 12 US centers. The primary outcome was aneurysm packing density (PD), which was assessed immediately post-procedure. The secondary outcomes were immediate and long-term aneurysm occlusion rate using the Raymond Scale, and independent functional outcome using the modified Rankin Scale (mRS). A secondary analysis investigated the influence of the use of 100% 360-complex coils on clinical and angiographic outcomes.

Results: 148 patients with 157 aneurysms met the inclusion and exclusion criteria. 58 (39.2%) patients with ruptured and 90 (61.8%) with unruptured aneurysms were treated using TARGET 360°, helical Coils, or both. Median age was 58.3 (IQR 48.1–67.4), 73% female, and 71.6% were Caucasian. Median follow-up time was 5.9 (IQR 4.0–6.9) months. The majority were treated with TARGET 360-coils (63.7%), followed by mixed and helical coils only. Peri-procedural morbidity and mortality was seen in 2.7% of patients. A good outcome at discharge (mRS 0–2) was seen in 89.9% of the full cohort, and in 84.5 and 93.3% in the ruptured and unruptured patients, respectively. The median packing density was 28.8% (IQR 20.3–41.1). Long-term complete and near complete occlusion rate was seen in 90.4% of aneurysms and complete obliteration was seen in 66.2% of the aneurysms. No significant difference in clinical and angiographic outcomes were noted between the pure 360-complex coiling vs. mixed 360-complex/Helical coiling strategies. In a multivariate analysis, predictors for long-term aneurysm occlusion were aneurysm location, immediate occlusion grade, and aneurysm size. The long-term independent functional outcome was achieved in 128/135 (94.8%) patients and all-cause mortality was seen in 3/148 (2%) patients.

Conclusion: In the multicenter TARGET Registry, two-thirds of aneurysms achieved long-term complete occlusion and 91.0% achieved complete or near complete occlusion with excellent independent functional outcome.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT01748903

Acute rerupture after coil embolization of ruptured intracranial saccular aneurysms: A literature review

Acute rerupture after coil embolization is defined as rerupture within three days after treatment; its prognosis is worse than that of rebleeding at other time periods. However, to date, little is known about complications during the acute phase. Therefore, we used the PubMed database to perform a review of acute rerupture after coil embolization of ruptured intracranial saccular aneurysms and increase our understanding. After reviewing the complications, we found that the cause of acute rerupture is unclear, but the following risk factors are involved: incomplete occlusion of the initial aneurysm, the presence of a hematoma adjacent to a ruptured aneurysm, an aneurysmal outpouching, poor Hunt-Hess grade at the time of treatment, and the location of the aneurysm in an anterior communicating artery. In addition, intraoperative rupture is a non-negligible cause. Acute rerupture after coil embolization mainly occurs within the first 24 hours after the procedure. Brain computed tomography is the gold standard for diagnosing acute rebleeding of a coiled aneurysm. For acute rerupture after coil embolization, prevention is critical, and complete occlusion of the aneurysm in the first session is the best protection against acute rebleeding. In addition, a restricted postembolization anticoagulation strategy is recommended for patients with high-risk aneurysms. For patients with an adjacent hematoma, surgical clipping is recommended. Most patients present no changes immediately after acute rebleeding because of their poor condition. However, surgical or endovascular treatments can be attempted if the patient is in an acceptable condition. Even so, the outcomes are typically unsatisfactory.