Evaluation of the Stability of Small Ruptured Aneurysms with a Small Neck after Embolization with Guglielmi Detachable Coils: Correlation between Coil Packing Ratio and Coil Compaction

Single-center experience of cerecyte coils in the treatment of intracranial aneurysms: initial experience and early follow-up results

BACKGROUND AND PURPOSE

Endovascular treatment of intracranial aneurysms using platinum coils is effective, but uncommonly aneurysms recur. New-generation coils, such as Cerecyte, aim to address this problem. This study examines the safety and efficacy of these coils in the treatment of a cohort of ruptured and unruptured aneurysms

MATERIALS AND METHODS

Sixty-seven patients with 68 aneurysms were included in the study. Of these, 51 were treated exclusively with the new polyglycolic acid (PGA)-containing coils, and 17 were treated with a combination of new PGA-containing and other coils. Initial and follow-up angiograms were graded according to the 3-point scale of occlusion. Follow-up angiography was available in 46 cases at 6 months. Based on occlusion grading at initial and follow-up angiography, aneurysms were classified into stable, improved, and worsened (recanalized) groups.

RESULTS

Of the exclusive new-coil cohort, 36 cases (70.6%) were initially completely occluded (grade 1), 12 (23.5%) showed filling at the neck (grade 2), and 3 (5.9%) showed contrast within the neck and sac (grade 3). Analysis of the follow-up angiograms showed 24 (70.6%) had stable occlusion, 3 (8.8%) had improved occlusion, and 7 (20.6%) had worsening occlusion. Data for cases treated with new PGA-containing coils together with bare platinum coils were also analyzed separately. Intraprocedural adverse events were noted in 4 cases (7.8%), but there were no clinical sequelae. There were no rebleeds in the follow-up period.

CONCLUSION

New PGA-containing coils show no excess in procedural and periprocedural complications over bare platinum coils, and the recanalization rate is comparable with bare platinum coils in the short term.

Angiographic and histological comparison of canine bifurcation aneurysms treated with first generation matrix and standard GDC coils

INTRODUCTION

It is claimed that bioactive coils induce accelerated and more durable aneurysm healing. Data supporting this claim are quite limited. Our purpose was to compare the angiographic and histological results obtained following treatment with different coil types.

METHODS

Bifurcation type aneurysms were surgically created in 24 dogs and treated using standard clinical techniques. Eight were treated with Guglielmi detachable coils (GDC), eight with first-generation Matrix coils, and eight with a combination of GDC and Matrix coils. The aneurysms were explanted and final angiographic evaluations performed 12 weeks after treatment. Angiographic and histological outcomes were documented.

RESULTS

Increased coil compaction with aneurysm recurrence was found in aneurysms treated with first-generation Matrix coils as compared to standard GDC (P = 0.0001). In aneurysms treated with first-generation Matrix coils thrombus organization was better than in those treated with either standard GDC coils (P = 0.008) or with a combination of GDC and Matrix coils (P = 0.04). In aneurysms treated with first-generation Matrix coils there were no endothelialized vascular clefts within the coil mass, but they were seen in the majority of aneurysms treated with GDC or a combination of GDC and Matrix coils (P = 0.003).

CONCLUSION

Aneurysms treated with first-generation Matrix coils showed the greatest degree of coil compaction and aneurysm recurrence on the final angiographic evaluation. Aneurysms treated with first-generation Matrix coils showed enhanced thrombus organization and absence of vascular clefts at the aneurysm neck that were markedly different from those treated with bare platinum coils or a combination of GDC and Matrix coils.

Retreatment of ruptured cerebral aneurysms in patients randomized by coiling or clipping in the International Subarachnoid Aneurysm Trial (ISAT)

BACKGROUND AND PURPOSE

Because the long-term security of endovascular treatments remains uncertain, a follow-up study of the patients treated in the International Subarachnoid Aneurysm Trial was performed to compare the frequency, timing, and consequences of aneurysm recurrence.

METHODS

Patient data were reclassified by actual treatment performed. Aneurysm and patient characteristics, including occlusion grades, time and type of retreatment, and clinical outcomes, were compared. The relationship between these variables and late retreatment as a surrogate for recurrence was analyzed by means of the Cox proportional hazards model.

RESULTS

Retreatment was performed in 191 of 1096 (17.4%) patients after primary endovascular coiling (EVT) and in 39 of 1012 patients (3.8%) after neurosurgical clipping. After EVT, 97 (8.8%) patients were retreated early and 94 (9.0%) late, 7 (0.6%) after rebleeding and 87 (8.3%) without. The mean time to late retreatment was 20.7 months. After neurosurgical clipping, 30 (2.9%) patients were retreated early and 9 (0.85%) late, 3 (0.3%) after rebleeding and 6 (0.6%) without. The mean time to late retreatment was 5.7 months. The hazard ratio (HR) for retreatment after EVT was 6.9 (95% CI=3.4 to 14.1) after adjustment for age (P=0.001, HR=0.97, 95% CI=0.95 to 0.98), lumen size (P=0.006, HR=1.1, 95% CI=1.03 to 1.18), and incomplete occlusion (P<0.001, HR=7.6, 95% CI=3.3 to 17.5).

CONCLUSIONS

Late retreatment was 6.9 times more likely after EVT. Younger age, larger lumen size, and incomplete occlusion were risk factors for late retreatment after EVT. After neurosurgical clipping, retreatments were earlier; whereas EVT retreatments continued to be performed throughout the follow-up period. Short-term follow-up imaging is therefore insufficient to detect recurrences after EVT.

Intracranial Aneurysms: Treatment with Bare Platinum Coils—Aneurysm Packing, Complex Coils, and Angiographic Recurrence

PURPOSE

To retrospectively assess, with three-dimensional rotational angiography, the relationship between packing, complex coils, and angiographic recurrence of aneurysms treated with coils.

MATERIALS AND METHODS

Informed consent was waived by the institutional review board that approved the study. Results at follow-up angiography of 255 aneurysms in 223 patients (161 female and 62 male patients; mean age, 48 years) were dichotomized into presence or absence of recurrence. The degree of packing of aneurysms treated with complex coils alone, with complex and helical coils, and with helical coils only was compared for significant differences. With generalized estimating equations analysis, relative risk (RR) for recurrence was calculated for mode of manifestation, duration of follow-up, aneurysm volume, packing, initial angiographic result, percentage of complex coils, aneurysm location, and multiplicity of aneurysms.

RESULTS

Follow-up angiography revealed recurrence in 28.6% of aneurysms at a mean follow-up of 12 months; 5.5% were amenable to re-treatment. Aneurysms treated with complex and those treated with helical coils only had a mean packing of 27% and 26%, respectively. There was no significant difference between packing of aneurysms treated with complex and those treated with helical coils (P = .538). Recurring and stable aneurysms both had a mean packing of 27%. Generalized estimating equations analysis showed significant differences between duration of follow-up and recurrence (P = .001, RR = 3.39), between aneurysm volume and recurrence (P < .001, RR = 6.15), and between hemorrhagic manifestation and recurrence (P = .002, RR = 3.17). There was no significant difference between packing and recurrence, between initial angiographic result and recurrence, between percentage of complex coils and recurrence, between aneurysm location and recurrence, or between multiplicity of aneurysms and recurrence.

CONCLUSION

More angiographic recurrences are detected over time. Complex coils do not augment aneurysm packing. Packing is not related to protection against recurrence.

Treatment of intracranial aneurysms with hydrogel coated expandable coils

BACKGROUND

Coiling of intracranial aneurysms with platinum coils sometimes results in relatively poor angiographic results which may be is related to low packing volumes achieved. Hydrogel coated expandable coils (HydroCoil) have been shown to achieve better aneurysm volume filling which may potentially result in lower recanalization rates. Currently there is limited clinical data on their safety and efficacy in aneurysm treatment.

METHODS

We analyzed data from a prospectively collected database on patients treated at the Toronto Western Hospital. The analysis included the patients' characteristics, aneurysm size, packing, procedure related complications, recanalization and clinical outcome.

RESULTS

Twenty-nine aneurysms were treated with HydroCoils only or in combination with other coils. The average calculated filling of the aneurysm volume was 74-76%. On the immediate post treatment angiograms, 44% of the berry type aneurysms were completely obliterated, 33% had a residual neck and, in 20%, a residual aneurysm was seen. Follow-up imaging was available in 23 cases. On imaging follow-up (from 2 days to 11 months) one dissecting aneurysm had recanalized. There were six technical/medical complications with no clinical consequences. Two clinically significant procedural related complications occurred.

CONCLUSIONS

HydroCoils can be used effectively to treat intracranial aneurysms. The volume expansion allows for much greater packing than described for bare platinum coils, which may result in better long-term results. The recanalization rate is low but the limited follow-up does not allow for any conclusion regarding the long-term outcome. The complication rate is similar to larger current series using bare platinum coils.

History of endovascular surgery: personal accounts of the evolution

Endovascular therapy has continuously evolved since it was first described in 1904. It was first used as a technique to inject particles to follow the flow into vascular lesions, and from the mid-seventies on, microballoons were developed to reach targets in the arterial vascular tree. Arteriovenous malformations were approached with catheters, the tip mounted by calibrated leak balloons. The embolizing material injected was cyanoacrylate labeled with Lipiodol (Lafayette Pharmacal, Lafayette, IN), a technique that is similar to what we use today. Flow-guided microballoons placed and detached in brain aneurysms eventually became unstable, making reperfusion and rupture possible. With the introduction of guidewire-supported microcatheters, controlled navigation in the endovascular tree became possible, allowing the injection of particles, liquid embolizing agents, or free coils. In 1991, detachable coils became available and brought new therapeutic concepts. Having learned that detachable coils could not be used to treat aneurysms, which were difficult to treat surgically, the neurosurgical community accepted this new technology primarily for patients in poor condition following aneurysmal subarachnoid hemorrhage. Increased experience led to better clinical results, and Guglielmi detachable coiling therapy began to be accepted also for patients with posterior circulation aneurysms. Recent controlled trials and new technologies improving the endovascular feasibility have raised the acceptance of endovascular therapy for brain aneurysms. The elegance of the endovascular approach was an important argument for this technology from its inception, but in early years, restricted endovascular efficacy limited the efficiency of embolizations. Increasing experience and exploding new technologies have made endovascular techniques not only safer but also as effective as microsurgery. The number of vascular pathologies where microsurgery is the only option is decreasing, and training in vascular neurosurgery may become the privilege of specialized centers in the future.

Clinical and angiographic outcome of intracranial aneurysms treated with Matrix detachable coils in Chinese patients

BACKGROUND

Aneurysm recurrence is an innate problem in endovascular treatment of aneurysms with coils. A coated coil system named Matrix (Boston Scientific Neurovascular, Fremont, CA), covered with a bioabsorbable polymeric material (polyglycolide/lactide copolymer [PGLA]), was developed to accelerate intraaneurysmal clot organization and fibrosis. The purpose of this study was to evaluate the efficacy and safety of the Matrix detachable coils in patients with intracranial aneurysms and aneurysmal recurrence rate.

METHODS

In a regional neurosurgical center in Hong Kong, data of patients undergoing endovascular embolization of intracranial aneurysm was collected. In a 20-month period, 42 patients with 44 aneurysms were treated by endovascular embolization using matrix coils alone or mixed with bare platinum coils. Thirty-four patients presented with ruptured aneurysms, and 8 patients presented with unruptured aneurysms.

RESULTS

Twenty-five patients (60%) had 6-month follow-up DSA, and 10 patients (24%) had 18-month follow-up DSA. Seven aneurysm recurrences were identified, amounting to 16% for all aneurysms and 14% for ruptured aneurysms. Four patients were treated by repeated embolization, and 2 patients were treated by microsurgical clipping. Two adverse events due to thromboembolism were noted. One 78-year-old lady with poor-grade subarachnoid hemorrhage treated by partial embolization died from rebleed at day 4. Another patient with partial embolization and spontaneous thrombosis of dorsal wall ICA aneurysm died at 2 months with aneurysm recanalization with rerupture. Twenty-six patients achieved favorable outcome (GOS score 4 or 5) at last follow-up. The aneurysm recurrence rate using bare platinum coils of the same center was 11% and 7% for all aneurysms and ruptured aneurysms, respectively.

CONCLUSION

Matrix coil embolization was safe, but there was no reduction in aneurysm recurrence using matrix coils alone or mixed with GDCs, compared with GDCs alone.

Endovascular treatment of intracranial aneurysms with matrix coils: immediate posttreatment results, clinical outcome and follow-up

INTRODUCTION

Endovascular aneurysm repair with coils has become a safe and effective alternative to surgical clipping. Efforts have been made to create coils that will facilitate aneurysm healing and reduce recurrence. The purpose of this study was to review the safety and durability of our aneurysm treatment using Matrix coils.

METHODS

A total of 39 aneurysms in 38 patients, aged 30 to 77 years, were treated using Matrix coils in 42 procedures. Two procedures were unsuccessful, and 12 were done using only Matrix coils. Aneurysm volume, packing density and percentage length of Matrix coils were calculated. The treatment results, procedural complication rate and clinical outcome were analyzed. Follow-up examinations were available for 34 procedures with a mean follow-up of 4.9 months (maximum 13.5 months).

RESULTS

Angiographic results were similar to those following the use of platinum coils, with complete occlusion or a residual neck in 82.5% of procedures. Six procedures (14%) were complicated with platelet aggregation. Recanalization occurred in 32% of the patients. Nine patients (26%) had major recanalization and were retreated. One patient had a re-bleed 5 months after the treatment resulting in severe disability. The mean packing density of 39.2% in the recanalized aneurysms was similar to that in the nonrecanalized group.

CONCLUSION

In our series, treatment with Matrix coils had a complication rate similar to that reported with platinum coils. However, we had a higher percentage of major recanalizations requiring retreatment. We believe that the absorption of the polymer contributes to the failure of formation of a stable scar within the aneurysm.

Balloon assistance as a routine adjunct to the endovascular treatment of cerebral aneurysms

BACKGROUND

The technique of BAC is attractive because the balloon theoretically allows for (1) "control" of blood flow in the vessel; (2) improved stability of the microcatheter in the aneurysm; (3) denser packing with coils; and (4) improved delineation of the neck of the aneurysm. The purpose of this communication is to document our outcomes with this technique and help determine if this technique is of benefit.

METHODS

Data on all endovascularily treated aneurysms have been gathered prospectively at our institution since March 2000. The first case of BAC was in November 2000. We have become very liberal in our indications, to the point where all aneurysms are considered for BAC. We document here our results obtained over a 1-year period, during which we treated 56 patients with 60 aneurysms in 58 coiling sessions using only bare platinum coils.

RESULTS

Balloon-assisted coiling was attempted in 50 (86%) of the 58 coiling sessions. Successful embolizations were achieved in all but 1 patient in whom BAC was attempted. There was one technique-related complication. The packing density for the BAC cases was, on average, 35.7% (median, 34.6%; SD, 14.1%). Follow-up angiography revealed a 13% class 3 recurrence rate.

CONCLUSION

With experience, BAC can be used in the endovascular treatment of most cerebral aneurysms. Although complications are associated with its use, we feel that the risk/benefit ratio is favorable. Excellent coil packing density with bare coils is achievable with this technique.

Long-term clinical and radiologic results of small cerebral aneurysms embolized with 1 or 2 detachable coils

BACKGROUND

Small cerebral aneurysms embolized with only 1 or 2 detachable coils often seem unstable and unsatisfactory. We tried to assess the long-term results of such embolized aneurysms.

METHODS

Among 231 intracranial saccular aneurysms embolized at the Asan Medical Center between July 1995 and July 2004, 27 small aneurysms were occluded with only 1 (n = 12) or 2 (n = 15) detachable coils. Clinical and radiologic results were evaluated retrospectively for the involved patients.

RESULTS

For the 1- and 2-coiled aneurysms, respectively, the mean dome sizes were 3.0 and 4.6 mm and the mean neck sizes were 1.9 and 2.7 mm. Most of the aneurysms were in the posterior circulation (19/27, 70%) and were found after bleeding (17/27, 63%). At the end of the embolization, complete occlusion in 19 aneurysms, residual neck in 1 aneurysm, and residual aneurysm in 7 aneurysms were attained angiographically. The mean packing ratios were 17.9% and 20.7% for the 1- and 2-coiled aneurysms, respectively. The mean clinical follow-up period of the patients was 41 months. No patient showed evidence of rebleeding; in addition, 1 patient with 1 coil and 2 patients with 2 coils were not followed up after discharge. Among the 10 follow-up DSAs or MRAs acquired after more than 8 months, radiologic major recurrences were detected in 2 patients after 10 and 15 months and second embolizations were done.

CONCLUSIONS

Although the 1- and 2-coiled small aneurysms with a relatively low packing ratio seemed unstable, they showed a relatively low incidence of rebleeding and recurrence.