Aneurysm Packing Density Research Articles

Mid-term safety and efficacy in small intracranial aneurysm coiling: results from TARGET® nano prospective independent core lab adjudicated multicenter registry.

The primary objective is to evaluate the safety and effectiveness of Stryker second generation Target® Nano Coils in the treatment of ruptured and unruptured small (<7 mm) intracranial aneurysms. The TARGET Registry is a prospective, two-arm study with independent medical event monitoring and core-lab adjudication. This paper describes the second arm of the TARGET registry. Patients with de novo intracranial aneurysms were embolized with 2nd generation TARGET Nano coils in 12 US centers. The primary efficacy outcome was adequate aneurysm occlusion (RR occlusion grade I-II) on follow-up. Primary safety outcome was treatment-related morbidity and mortality. Secondary outcomes included aneurysm packing density immediately post-procedure, immediate adequate occlusion, aneurysm re-access rate, retreatment rate and clinical outcomes using modified ranking scale. A secondary analysis investigated the influence of using Nano-predominant coils (≥2/3 of total coil-length) vs. non-Nano-predominant coils (<2/3 of total length). 150 patients with 155 aneurysms met the inclusion and exclusion criteria. (31%) patients with ruptured and (69%) with unruptured aneurysms were treated using TARGET coils. Median age was 58.8 (SD 12.7), 74.7% were females, and 80% were Caucasians. Mean follow-up was 5.23 (SD 2.27) months. Peri-procedural mortality was seen in 2.0% of patients. Good outcome at discharge (mRS 0-2) was seen in 81.3% of the cohort. The median packing density (SD) was 29.4% (14.9). Mid-term complete/near complete occlusion rate was seen in 96% of aneurysms and complete obliteration was seen in 75.2% of aneurysms. Patients treated predominantly with Nano coils had higher PD (32.6% vs. 26.1%, p < 0.001). There was no significant difference in clinical and angiographic outcomes. The mid-term mRS0-2 was achieved in 106/109 (97.2%) patients. All-cause mortality was 5/115 (4.3%). In the multicenter TARGET Registry, 75.8% of aneurysms achieved mid-term complete occlusion, and 96% achieved complete/near complete occlusion with excellent independent functional outcome.

Volume embolization ratio of coiled cerebral aneurysms, does awake technique affect the results?

BackgroundDespite the great innovations in the neuroendovascular techniques and related materials, there are still notable percentages of recurrent cerebral aneurysms after aneurysm coiling. Aneurysm packing density is well known to affect the initial angiographic result of aneurysm embolization and has a crucial role in the stability of aneurysm obliteration. Although aneurysm coiling is commonly performed under general anesthesia, it could be performed under local anesthesia in certain circumstances.ObjectiveThe purpose of this study is to compare the volume embolization ratio (VER) and angiographic results of cerebral aneurysm embolization performed under local and general anesthesia.Materials and methodsThis is a retrospective cohort analysis of 20 consecutive cases of coiled cerebral aneurysms that were coiled under LA. Further, 15 cerebral aneurysm coil embolization cases have been collected from our data as matched control group.ResultsEmbolization was performed under local anesthesia (Group A) in 20 patients (57.1%) and under general anesthesia (Group B) in 15 patients (42.9%). At the end of the procedure, control angiogram revealed complete obliteration in 13 patients (37.1%), while incomplete obliteration was detected in 22 patients (62.9%). The mean VER 27.9 ± 11.8 without a significant difference between both groups of the study as the VER of Group (A) was 26.05 ± 8.4 and that of Group B was 30.44 ± 15.2. Follow-up angiography at 1 year revealed complete obliteration in 17 (48.6%) of the coiled aneurysms, while incomplete obliteration was detected in 18 patients (51.4%).ConclusionsEndovascular coiling of cerebral aneurysms under local anesthesia is a safe and feasible procedure without significant effects on the VER.

Technical Success and Early Efficacy in 851 Patients with Saccular Intracranial Aneurysms: A Subset Analysis of SMART, a Prospective, Multicenter Registry Assessing the Embolization of Neurovascular Lesions using the Penumbra SMART COIL System

The Prospective, Multicenter Registry Assessing the Embolization of Neurovascular Lesions Using the Penumbra SMART COIL® System (SMART) is the largest prospective, multicenter, postmarket registry established to gather real-world experience on Penumbra (Alameda, USA) SMART COIL System, PC400, and POD embolization coils. The goal of this study is to report the technical success and efficacy of SMART COIL System coils in treating saccular intracranial aneurysms. This subgroup analysis from the SMART registry included patients with saccular intracranial aneurysms treated using ≥75% SMART COIL System or PC400 coils. Baseline and procedural data, angiographic data, and clinical outcomes were collected. Predictors of catheter kickout, packing density, and postprocedural angiographic outcome were analyzed using multivariable regression models in saccular aneurysm cases. Between June 2016 and August 2018, the SMART registry enrolled 995 patients at 68 sites, of which 851 of 995 (85.5%) were treated for saccular aneurysms (mean age, 59.9 years). Aneurysms had a mean size of 6.8 mm, were wide neck in 63.1%, and ruptured in 31.0% of patients. Mean aneurysm packing density was 32.3%. Postprocedural Raymond-Roy Occlusion Classification (RROC) I-II was achieved in 80.3% of patients; smaller aneurysms, non-wide-neck aneurysms, and high packing density were predictive of RROC I-II. Overall, mean fluoroscopic time was 43.4 minutes, rate of reaccess attempts because of catheter kickout was 6.2%, and mean procedure time was 83.2 minutes. SMART COIL System coils achieved good technical success and adequate occlusion in treating saccular intracranial aneurysms in a real-world setting.

Influence of neurovascular embolic coil primary wind diameter on aneurysm packing density and case costs

Aims Endovascular coiling is a common modality for treating intracranial aneurysms; however, recanalization occurs in approximately 1 in 5 cases, with downstream consequences of regrowth and rupture. Aneurysm packing density >24% reduces recanalization risk; packing density can be increased by inserting additional coils or by using coils with larger volumetric filling. Coil volume depends on length and primary wind diameter (PWD). This study evaluated the influence of PWD on packing density and total case costs. Materials and methods Two hypothetical scenarios and one case study were analyzed. In scenario one, the number of coils required to achieve packing density >24% in a hypothetical aneurysm was determined for 0.012″ vs. 0.010″ PWD coils. In scenario two, the total length of 0.010″ vs. 0.012″ PWD coils required to achieve a packing density >24% was analyzed relative to aneurysm volume. In the case study, packing densities with one 0.012″ PWD coil (actual scenario) and one 0.010″ PWD coil (theoretical scenario) were compared. Results In scenario one, cost savings would be realized by using four 0.012″ PWD coils vs. seven 0.010″ PWD coils to achieve packing density >24%. In scenario two, greater volumetric filling of 0.012″ vs. 0.010″ PWD coils was correlated with lower total length of coil required. In the case study, a 0.012″ PWD coil achieved packing density >24%, whereas an equivalent length 0.010″ PWD coil would not. Limitations Theoretical modeling was used to explore the impact of coil PWD on aneurysm packing density. In clinical practice, packing density depends not only on PWD but on its length, shape, distribution within an aneurysm, and other recanalization risk factors. Conclusions Coil PWD influences packing density, the number of coils required to achieve a specific packing density, and total case costs. Using 0.012″ PWD coils may provide cost and procedural efficiencies.

Does Increasing Packing Density Using Larger Caliber Coils Improve Angiographic Results of Embolization of Intracranial Aneurysms at 1 Year: A Randomized Trial.

The impact of increased aneurysm packing density on angiographic outcomes has not been studied in a randomized trial. We sought to determine the potential for larger caliber coils to achieve higher packing densities and to improve the angiographic results of embolization of intracranial aneurysms at 1 year. Does Embolization with Larger Coils Lead to Better Treatment of Aneurysms (DELTA) was an investigator-initiated multicenter prospective, parallel, randomized, controlled clinical trial. Patients had 4- to 12-mm unruptured aneurysms. Treatment allocation to either 15- (experimental) or 10-caliber coils (control group) was randomized 1:1 using a Web-based platform. The primary efficacy outcome was a major recurrence or a residual aneurysm at follow-up angiography at 12 ± 2 months adjudicated by an independent core lab blinded to the treatment allocation. Secondary outcomes included indices of treatment success and standard safety outcomes. Recruitment of 564 patients was judged necessary to show a decrease in poor outcomes from 33% to 20% with 15-caliber coils. Funding was interrupted and the trial was stopped after 210 patients were recruited between November 2013 and June 2017. On an intent-to-treat analysis, the primary outcome was reached in 37 patients allocated to 15-caliber coils and 36 patients allocated to 10-caliber coils (OR = 0.931; 95% CI, 0.528-1.644; P = .885). Safety and other clinical outcomes were similar. The 15-caliber coil group had a higher mean packing density (37.0% versus 26.9%, P = .0001). Packing density had no effect on the primary outcome when adjusted for initial angiographic results (OR = 1.001; 95% CI, 0.981-1.022; P = .879). Coiling of aneurysms randomized to 15-caliber coils achieved higher packing densities compared with 10-caliber coils, but this had no impact on the angiographic outcomes at 1 year, which were primarily driven by aneurysm size and initial angiographic results.

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

Selective occlusion of splenic artery aneurysms with the coil packing technique: the impact of packing density on aneurysm reperfusion correlated between contrast-enhanced MR angiography and digital subtraction angiography.

The aim was to evaluate the relationship between coil packing densities after splenic artery aneurysm (SAA) treatment using detachable microcoils and rates of SAA reperfusion and to suggest a post-treatment surveillance protocol using contrast-enhanced MRA. Evaluated were 16 patients (4 men; mean age 46.7), who underwent true SAA embolization using detachable microcoils (Concerto, Medtronic). SAAs were treated by selective coil packing (CP) or stent-assisted coil exclusion (SAC). Contrast-enhanced magnetic resonance angiography (CE-MRA) and digital subtraction angiography (DSA) were performed at 3months post-procedure and correlated. Primary CP was used in 13 patients, while SAC was used in three patients. On follow-up, complete aneurysm occlusion was seen in seven patients (43.8%). Sac reperfusion occurred in nine patients (56.2%) and was demonstrated in all CE-MRA and six DSA studies. Mean aneurysm packing density was 20.10 ± 8.05% for the CP group and 32.90 ± 11.95% for the SAC group (p = 0.038). There was a significant difference in the incidence of aneurysm sac reperfusion on CE-MRA study between CP and SAC (9 vs. 0). No sac reperfusion was seen in aneurysms with packing densities ≥ 29%, irrespective of either embolization method. Favorable midterm results for coil packing of SAAs seem to depend on the coil packing density with a coil volume approximately a quarter of the aneurysm volume being most effective. Follow-up should involve the use of CE-MRA as this modality has been shown to be superior over DSA in detecting aneurysm reperfusion and coil compaction. Level IV, therapeutic study.

Impact of Coil Packing Density and Coiling Technique on Occlusion Rates for Aneurysms Treated with Stent-Assisted Coil Embolization

Stent-assisted coil embolization is an established endovascular technique for wide-necked intracranial aneurysms. Although recanalization after coil embolization is reduced with the use of a stent, the impact of aneurysm packing density is less clear in stent-coiled aneurysms. The purpose of the present study was to assess packing density in stent-coiled aneurysms and evaluate its effect on recanalization and retreatment. A retrospective analysis of consecutive aneurysms treated with stent-assisted coiling was performed at 2 academic institutions between 2007 and 2015. Aneurysm occlusion was assessed using digital subtraction angiography. Packing density was calculated using the AngioCalc app. Two hundred fifty-three aneurysms were identified (median age, 59 years). The median packing density was 35.3%. At last follow-up, 72.7% of aneurysms were completely obliterated and 19.4% had a neck remnant. Complete occlusion was associated with smaller aneurysms and coiling through stent interstices. A higher packing density was associated with increased rate of complete occlusion when analyzed as continuous variable. After adjustment for confounding variables, packing density was no longer predictive of complete occlusion (odds ratio= 1.018, P=0.122). Similarly, there was no significant association between aneurysm occlusion, retreatment, and packing density when assessed by categories of high (>22%), moderate (12%-22%), and low (<12%) packing density. Aneurysm size remains the most important predictor of aneurysm recanalization and retreatment after stent-assisted coiling. Although higher packing densities were associated with increased rates of aneurysm occlusion in unadjusted statistical comparisons, this finding was no longer significant after adjusting for confounders.

E-001 TARGET Intracranial Aneurysm Coiling Prospective Multicenter Registry: Initial Periprocedural Results in 120 Patients

Background and purposeTo describe the periprocedural results of the TARGET Registry, an on-going, prospective, non-randomised, multicenter, real-world study of patients with ruptured or unruptured intracranial aneurysms that are embolised with...

O-009 Prospective Packing Density: A Single Center Study Investigating the Effects of Prospectively Measuring Packing Density Prior to Choosing Coils For the Treatment of Intracranial Aneurysms

ObjectiveMultiple studies have shown, retrospectively, the inverse relationship between packing density and aneurysm recurrence. Furthermore, it has been shown that prospectively measuring the packing density, by carefully selecting the first...

Abstract TP76: Medium-Term Angiographic Follow-up and Packing Density Analysis in a Series of 67 Consecutive Intracranial Aneurysms Treated Endovascularly with a Single Coil

Purpose: To determine the medium-term angiographic outcome and packing density threshold for complete aneurysm occlusion at follow-up in a series of cerebral aneurysms treated with a single coil. Methods: We retrospectively identified all cerebral aneurysms treated with a single coil at our institution from July 1997 until September 2011. We recorded aneurysm dimensions, neck size, packing density, and follow-up catheter or MR angiograms to determine the angiographic outcome at last follow-up according to the Raymond scale. We then performed receiver operating characteristic (ROC) analysis of the likelihood of complete aneurysm occlusion at follow-up to determine the packing density maximum operating point (MOP). Results: Eighty-one aneurysms in 79 patients were treated with a single coil at our institution during the study period. Sixty-four patients were female (81%) and mean age was 53 years (range 23-87 years). Mean maximum aneurysm dimension was 2.8mm (range 1.6-4.8mm), and mean dome-to-neck ratio was 1.3 (median 1.3, range 0.8-1.9). Mean aneurysm packing density was 35.3% (median 32.8%, range 10.2-94.3%). Three patients with ruptured aneurysms died during the hospitalization (7.7%), and follow-up angiographic examinations were performed in 65 patients with 67 aneurysms (85.9%). Mean time to last angiographic follow-up was 26.4 months (range 4-102 months). Complete aneurysm occlusion at last follow-up was present in 46 aneurysms (68.7%), a neck remnant in 16 aneurysms (23.9%) and sac recanalization in 5 aneurysms (7.4%). ROC analysis of the likelihood of complete aneurysm occlusion at last follow-up yielded a packing density MOP of &gt;36.3%, with a specificity of 85.7%, sensitivity of 47.8%, and an area under the curve of 0.61 (95%CI 0.49-0.73). There was a statistically-significant difference in the likelihood of complete aneurysm occlusion at last follow-up between the 25 aneurysms with a packing density &gt;36.3% (88%), and the 42 aneurysms with a packing density ≤36.3% (57.1%, OR 5.5 [95%CI 1.4-21.3], p-value 0.009). Conclusion: Achieving a packing density &gt;36.3% predicts a significantly higher likelihood (88%) of complete aneurysm occlusion at medium-term angiographic follow-up in cerebral aneurysms treated with a single coil.

005 DeltaPaq coils in the treatment of intracranial aneurysms: packing density, clinical and angiographic results

Purpose: Recanalization of the aneurysm sac is a major drawback of endovascular embolization that often necessitates retreatment. Recent evidence suggests that increased packing density of coils within the aneurysm sac...

Response to Letter by van Rooij and Sluzewski

Response: We read the letter by Drs Willem Jan van Rooij and Menno Sluzewski criticizing our study,1 and herein address their critiques of our methodology and results. We find the comments of Drs van Rooij and Sluzewski similar in content and tone to their recent letter criticizing another study of packing density which used comparable methods for calculating aneurysm sac volumes.2,3 We invite interested readers to review this letter, from which we conclude that Drs van Rooij and Sluzewski share 4 of our beliefs, which are central to the purpose and design of our study: (1) density of aneurysm packing (volumetric percentage occlusion or VPO) affects durability of occlusion and thus outcome, (2) VPO is generally inversely related to aneurysm volume (higher packing densities are usually achieved in smaller aneurysms), (3) a study measuring packing density must use the most accurate method of calculating …

Embolization of Intracranial Aneurysms With Hydrogel-Coated Coils Versus Inert Platinum Coils

The durability of aneurysm coil embolization is thought to depend on packing density. The expansile property of hydrogel coating on coils increases volumetric packing per coil length. We describe our experience using hydrogel-coated coils (HydroCoils) compared with inert platinum coils in intracranial aneurysm embolization. Fifty aneurysms embolized primarily using HydroCoils from 2003 to 2004 were compared with 57 volume- and shape-matched aneurysms treated with standard platinum coils from 2000 to 2003. Outcome measures included volumetric percentage occlusion (VPO), length and number of coils used, procedure time, fluoroscopy time, contrast volume, coil cost, length of hospital stay, and durability of therapy. Seventeen/26/5 small/medium/large aneurysms treated with HydroCoils were matched with 29/24/4 small/medium/large aneurysms treated with inert platinum. HydroCoil embolization yielded significantly greater VPO (84.8% versus 29.8%; P<0.001), decreased average total coil length used per aneurysm (33.2 versus 44.3 cm), reduced fluoroscopy time (53.2 versus 65.2 minutes; P=0.016), but increased contrast volume used (174.8 versus 112.9 cc; P<0.001). There were no differences in length of hospital stay. Procedure-related morbidity and mortality rates in the HydroCoil cohort were 4% and 0%, respectively. Follow-up angiography at mean 12.3 months revealed lower aneurysm recurrence rates (17% versus 24%; number-needed-to-treat [NNT] 14.3). Initial costs associated with HydroCoil embolization were higher ($5835 versus $4017; P=0.004) but countered by lower retreatment rates (10% versus 17%; NNT 14.3). HydroCoil embolization achieves greater aneurysm packing density with decreased coil length. Initial durability data favor HydroCoils, with lower recurrence and retreatment rates.