Embolisation of recently ruptured intracranial aneurysms

Recovery of posterior communicating artery aneurysm induced oculomotor nerve palsy: a comparison between surgical clipping and endovascular embolization

BACKGROUND

Oculomotor nerve palsy (ONP) is a common symptom of posterior communicating artery aneurysm (PcomAA) that can lead to impaired eye movement and pupil dilation. Currently, surgical clipping and endovascular embolization are the two most popular treatment methods for PcomAA-induced ONP; however, the recovery outcome between the two methods remains to be elucidated.

METHODS

In the present study, we thoroughly compared the pretreatment factors and recovery outcome of the two treatments on 70 patients with PcomAA-induced ONP. The patients were separated into two groups based on the treatment that was received. Pretreatment factors, including age, sex, time period between ONP onset and treatment, ONP type, aneurysm diameter, status of subarachnoid hemorrhage and aneurysm rupture were recorded for each individual patient. Recovery outcome of the patients was assessed over a 12-month period.

RESULTS

No significant differences were observed in any of the analyzed factors. Importantly, we revealed a significantly higher full recovery rate for the patients receiving the surgical clipping treatment than the ones that received the endovascular embolization treatment. In addition, we showed that patients' age was negatively correlated with the recovery extent in both treatment groups.

CONCLUSIONS

The outcome of our study suggests that surgical clipping might be a better option to treat PcomAA-induced ONP.

Endovascular Treatments Performed Collaboratively by the Society of Korean Endovascular Neurosurgeons Members : A Nationwide Multicenter Survey

Objective

Since less invasive endovascular treatment was introduced to South Korea in 1994, a considerable proportion of endovascular treatments have been performed by neuroradiology doctors, and endovascular treatments by vascular neurosurgeons have recently increased. However, few specific statistics are known regarding how many endovascular treatments are performed by neurosurgeons. Thus, authors compared endovascular treatments collaboratively performed by vascular neurosurgeons with all cases throughout South Korea from 2013 to 2017 to elucidate the role of neurosurgeons in the field of endovascular treatment in South Korea.

Methods

The Society of Korean Endovascular Neurosurgeons (SKEN) has issued annual reports every year since 2014. These reports cover statistics on endovascular treatments collaboratively or individually performed by SKEN members from 2013 to 2017. The data was requested and collected from vascular neurosurgeons in various hospitals. The study involved 77 hospitals in its first year, and 100 in its last. National statistics on endovascular treatment from all over South Korea were obtained from the Healthcare Bigdata Hub website of the Health Insurance Review & Assessment Service based on the Electronic Data Interchange (EDI) codes (in the case of intra-arterial (IA) thrombolysis, however, statistics were based on a combination of the EDI and I63 codes, a cerebral infarction disease code) from 2013 to 2017. These two data sets were directly compared and the ratios were obtained.

Results

Regionally, during the entire study period, endovascular treatments by SKEN members were most common in Gyeonggi-do, followed by Seoul and Busan. Among the endovascular treatments, conventional cerebral angiography was the most common, followed by cerebral aneurysmal coiling, endovascular treatments for ischemic stroke, and finally endovascular treatments for vascular malformation and tumor embolization. The number of endovascular treatments performed by SKEN members increased every year.

Conclusion

The SKEN members have been responsible for the major role of endovascular treatments in South Korea for the recent 5 years. This was achieved through the perseverance of senior members who started out in the midst of hardship, the establishment of standards for the training/certification of endovascular neurosurgery, and the enthusiasm of current SKEN members who followed. To provide better treatment to patients, we will have to make further progress in SKEN.

Evaluation of safety, efficacy and clinical outcome after endovascular treatment of aneurysmal subarachnoid hemorrhage in coil-first setting. A 10-year series from a single center

INTRODUCTION

The endovascular treatment (EVT) of ruptured cerebral aneurysms has been widely adopted after the publication of the International Subarachnoid Aneurysm Trial. In this study, we sought to evaluate the safety and efficacy of the EVT for ruptured aneurysms based on 10-year series from a single center with coil-first strategy.

METHODS

All patients with aneurysmal subarachnoid hemorrhage (aSAH) treated between 2007 and 2016 were retrospectively reviewed and divided according to initial treatment into an EVT and a microsurgical clipping (MSC) group. Clinical and radiological findings at presentation, treatment modalities and procedural complications were recorded. The angiographic and clinical outcome was compared between the two groups.

RESULTS

A total of 587 patients with aSAH were reviewed (452 EVT, 135 MSC). There were no significant differences in mean age or the Hunt and Hess grades. Parenchymal hemorrhage (PH) was more frequent in the MSC. Procedure related complications of the acute treatment were recorded in 5.5% and 32% in the EVT and MSC, respectively. The rate of retreatment was 21.9% in the EVT and 5.9% in the MSC. Late rehemorrhage was not observed in either group. There was no significant difference in the clinical outcome between the two treatment groups after adjustment for other prognostic factors.

CONCLUSION

The majority of ruptured intracranial aneurysms can be managed via an endovascular approach in the acute phase with excellent safety profile and good efficacy. Despite the high rate of reperfusion after primary endovascular approach, retreatment has a very low rate of complications and the rate of recurrent hemorrhage is very low.

Early outcomes and perioperative complications of endovascular embolization in patients with aneurysmal SAH

BACKGROUND

We still lack reliable data on the outcomes of endovascular coiling for ruptured cerebral aneurysms. As this is still an evolving technique, the outcomes of the procedures performed in the past and more recently cannot be directly compared. We present the early outcomes of endovascular coiling in a relatively large group of patients with ruptured intracranial aneurysms.

METHOD

The study included 190 consecutive patients (a total of 216 aneurysms) subjected to endovascular coiling in 2006-2013 (127 women aged 56±13 years and 63 men aged 50± 15 years). Up to 87.5% of the aneurysms were located within anterior circulation. Most patients presented with "mild to moderate" subarachnoid hemorrhages (85% of Hunt &Hess scores 1-3, and 72% of Fisher scores 1-3).

RESULTS

Embolization was feasible in 176 (92.6%) patients. In 14 cases, the embolization was not attainable due to unfavorable anatomy of the aneurysm, intraoperative vasospasm and/or aneurysm rupture, or prolapse of a coil. Early complications related to the procedure were recorded in 23 (13.1%) patients. The most common perioperative complication was aneurysm rupture. All fatal complications occurred in patients with aneurysms located at the anterior circle of Willis. At the time of discharge, 126 patients scored 4 or 5 on the Glasgow Outcome Scale.

CONCLUSIONS

Endovascular embolization is an effective and relatively safe method for treatment of ruptured cerebral aneurysms. Complications related to the procedure are significantly less frequent in the case of vertebral-basilar complex aneurysms.

Endovascular Therapy for Ruptured Cerebral Aneurysms in the Elderly: Poor Accessibility of the Guiding Catheter and Use of Local Anesthesia as the Predictors of Procedure-Related Rupture

BACKGROUND

Endovascular therapy is favored for ruptured intracranial aneurysms in the elderly. However, poor accessibility to the aneurysm through the parent artery and use of local anesthesia in this age group may predispose to intraprocedural complications.

OBJECTIVE

To evaluate whether age-related poor access to the ruptured target aneurysm and use of local anesthesia are associated with increased incidence of procedure-related rupture during endovascular embolization.

METHODS

A total of 117 patients with 117 ruptured aneurysms underwent endovascular embolization at a single institution. Correlation of increasing age with poor accessibility of the guiding catheter was analyzed. In addition, the distance from the aneurysm to the guiding catheter was investigated to identify an association with incidence of procedure-related rupture. Correlation of local anesthesia with procedure-related rupture was also evaluated in the multivariable analysis.

RESULTS

Increasing age was significantly associated with poor accessibility of the guiding catheter (P = .001, Mann-Whitney U test). Procedure-related rupture occurred in 9 of 117 aneurysms (7.7%). Longer distance between distal aneurysms and low-positioned guiding catheters carried a higher risk of procedure-related rupture than a shorter distance between proximal aneurysms and high-positioned guiding catheters (odds ratio, 19.3; 95% confidence interval, 1.84-201; P = .01, multivariable analysis). Use of local anesthesia was also a significant risk factor of procedure-related rupture by multivariable analysis.

CONCLUSION

Increasing age was correlated with poor accessibility of the guiding catheter in endovascular embolization of ruptured intracranial aneurysms. Distally located aneurysms treated through a low-positioned guiding catheter and use of local anesthesia increased the risk of procedure-related rupture.

A Retrospective Comparison of the Influence of Surgical Clipping and Endovascular Embolization on Recovery of Oculomotor Nerve Palsy in Patients With Posterior Communicating Artery Aneurysms

BACKGROUND:

Oculomotor nerve palsy (ONP) is a common symptom of posterior communicating artery aneurysms (PcomAAs). Surgical clipping and endovascular embolization are used to treat PcomAAs with ONP.

OBJECTIVE:

To analyze the impact of these 2 techniques on recovery of ONP caused by PcomAAs.

METHODS:

The clinical data for 176 patients with intracranial PcomAAs with ONP admitted to the Department of Neurosurgery, Sichuan Provincial People's Hospital, between June 2008 and May 2013 who undergone surgical clipping or endovascular embolization were studied retrospectively. The 2 treatment groups were compared with respect to age, sex, aneurysm size, levels of hypertension and hyperlipidemia, preadmission ONP duration, subarachnoid hemorrhage (SAH), complete ONP, postoperative recovery time from ONP symptoms, and degree of recovery. The follow-up duration was a minimum of 12 months. Multivariate Cox regression was used for analysis.

RESULTS:

A total of 132 patients were treated by surgical clipping, and 44 were treated by endovascular embolization. Significant differences were found in postoperative recovery time (83.87 ± 34.70 days for clipping and 137.45 ± 44.94 days for embolization, P < .001) and recovery rates (130 [98.5%] for clipping and 30 [68.2%] for embolization, P < .001). The period between ONP onset and admission was associated with recovery. Postoperative complications included significant cerebral vasospasms (6 in the clipping group and 2 in the embolization group) and hydrocephalus (16 in the clipping group and 9 in the embolization group).

CONCLUSION:

Simultaneous elimination of 2 injury mechanisms, compression and pulsation, when treating the oculomotor nerve by surgical clipping may be more advantageous than endovascular embolization to treat ONP caused by PcomAA.

Endovascular treatment of subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a common and devastating form of stroke. A large number of patients with aSAH develop angiographic or clinical vasospasm responsible for high morbidity and mortality. Rapid advances in the field of interventional neurology and the development of minimally invasive techniques have resulted in expansion of potential therapeutic applications. Treatment of aSAH has benefited from this rapid advance in the field of endovascular therapies. In the first section of the review, we discuss the therapeutic options and techniques for embolizations of intracranial aneurysms. In the second section, we discuss evolving endovascular treatment methods employed to intervene in delayed complications of cerebral vasospasm in patients with aSAH.

Patterns in neurosurgical adverse events: endovascular neurosurgery

As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in endovascular neurosurgery concerning the frequency of adverse events in practice, their patterns, and current methods of reducing the occurrence of these events. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice.

Based on a review of the literature, thromboembolic events appeared to be the most common adverse events in endovascular neurosurgery, with a reported incidence ranging from 2% to 61% depending on aneurysm rupture status and mode of detection of the event. Intraprocedural and periprocedural prevention and rescue regimens are advocated to minimize this risk; however, evidence on the optimal use of anticoagulant and antithrombotic agents is limited. Furthermore, it is unknown what proportion of eligible patients receive any prophylactic treatment.

Groin-site hematoma is the most common access-related complication. Data from the cardiac literature indicate an overall incidence of 9% to 32%, but data specific to neuroendovascular therapy are scant. Manual compression, compression adjuncts, and closure devices are used with varying rates of success, but no standardized protocols have been tested on a broad scale. Contrast-induced nephropathy is one of the more common causes of hospital-acquired renal insufficiency, with an incidence of 30% in high-risk patients after contrast administration. Evidence from medical fields supports the use of various preventive strategies.

Intraprocedural vessel rupture is infrequent, with the reported incidence ranging from 1% to 9%, but it is potentially devastating. Improvements in device technology combined with proper endovascular technique play an important role in reducing this risk.

Occasionally, anatomical or technical difficulties preclude treatment of the lesion of interest. Reports of such occurrences are scant, but existing series suggest an incidence of 4% to 6%. Management strategies for radiation-induced effects are also discussed. The incidence rates are unknown, but protective techniques have been demonstrated.

Many of these complications have strategies that appear effective in reducing their risk of occurrence, but development and evaluation of systematic guidelines and protocols have been widely lacking. Furthermore, there has been little monitoring of levels of adherence to potentially effective practices. Protocols and monitoring programs to support integrated implementation may be broadly effective.

Intraprocedural aneurysmal rupture during coil embolization of brain aneurysms: role of balloon-assisted coiling

BACKGROUND AND PURPOSE

Intraprocedural aneurysmal rupture is a feared complication of coil embolization of intracranial aneurysms and is associated with high rates of morbidity and mortality. We report the incidence, endovascular management, and clinical outcome of patients with IAR, with emphasis on the role of the balloon-assisted technique.

MATERIALS AND METHODS

We conducted a retrospective analysis of all intracranial aneurysms treated by coil embolization between September 2001 and June 2011. All patients with IAR were studied. Comparison of immediate clinical outcomes was performed by using univariate analysis (Fisher exact test).

RESULTS

Of 652 intracranial aneurysms treated with coil embolization, an IAR occurred in 22 (3.4%). Rupture occurred during placement of coils in 18 cases, microcatheters in 2 cases, and a guidewire in 1 case, and during induction of anesthesia in 1 case. Before treatment, 15 of 22 (68%) patients were in good clinical condition (WFNS grade I). There were fewer patients with worsening of the WFNS grade following an IAR when the balloon-assisted technique was used (7.7%) compared with when it was not (55.5%) (P = .023). Death occurred in 2 (9.1%) patients.

CONCLUSIONS

IAR is a potentially serious complication of coil embolization. If IAR occurs, balloon-assistance is helpful in obtaining rapid hemostasis resulting in better short-term outcomes.

In vitro delivery, cytotoxicity, swelling, and degradation behavior of a liquid-to-solid gelling polymer system for cerebral aneurysm embolization

This study examines the in vitro characteristics of a crosslinking polymer system for cerebral aneurysm embolization. The polymeric material is composed of poly(propylene glycol)diacrylate (PPODA) and pentaerythritol tetrakis(3-mercaptopropionate) (QT), formulated with the liquid contrast agents Conray™ or Omnipaque™ 300. The PPODA-QT system was tested for delivery feasibility through mock delivery into a model aneurysm. Cytotoxicity was performed by exposing 3T3 cells to gel formulations, followed by a cell viability assay. Swelling was measured on samples submerged in 150 mM phosphate buffered saline at 37 or 50°C. The same samples underwent compression testing to assess degradation, characterized by reduction in Young's modulus over time. The PPODA-QT system was easily deliverable to mock aneurysms. Cytotoxicity results indicated that Conray-formulated gels are initially less toxic than Omnipaque-formulated gels, but show greater susceptibility to swelling and degradation over time. In general, these experiments represented more challenging conditions than would be present in vivo, and therefore, reported results are likely overestimations of in vivo outcomes. However, these results highlight potential issues with each PPODA-QT formulation. Given the desired outcome of neointimal tissue growth over the polymer material, initial cytotoxicity may be more important than long-term factors when choosing an optimal formulation for aneurysm embolization.

In vivo experimental aneurysm embolization in a swine model with a liquid-to-solid gelling polymer system: initial biocompatibility and delivery strategy analysis

OBJECTIVE

Current treatments for cerebral aneurysms are far from ideal. Platinum coils are prone to compaction, and currently used liquid embolics are delivered with angiotoxic agents. This work presents initial in vivo studies of a novel liquid-to-solid gelling polymer system (PPODA-QT), focusing on biocompatibility and effective delivery strategies.

METHODS

PPODA-QT was used to embolize surgically created lateral wall carotid artery aneurysms in swine using three delivery strategies. Group 1 aneurysms were completely filled with PPODA-QT (n = 5), group 2 aneurysms were subcompletely (80%-90%) filled (n = 3), and group 3 aneurysms underwent three-dimensional coil placement followed by polymer embolization (n = 3). The study was designed such that three animals per treatment group survived to 1 month.

RESULTS

The group 1 delivery strategy (100% filling) resulted in survival of 3/5 animals. This strategy led to aneurysm stretching, which resulted model failure in 2/5 animals. Group 2 aneurysms, although initially <100% filled with the polymer, displayed robust neointimal tissue coverage and complete obliteration after 1 month. Group 3 aneurysms showed less prominent neointimal tissue coverage as well as two instances where excess polymer was found in the parent vessel. The PPODA-QT material showed good biocompatibility with vascular tissue in all animals at 1 month.

CONCLUSIONS

This small-scale pilot study highlighted first-time in vivo use of PPODA-QT as an embolic agent for aneurysm treatment. Filling aneurysms to 80% to 90% capacity proved to be a safe and effective delivery strategy, and PPODA-QT showed excellent biocompatibility. This study indicates that future investigation of PPODA-QT for aneurysm embolization is warranted, as it may prove to be a viable alternative to current embolic materials.

Sixteen-year single-surgeon experience with coil embolization for ruptured intracranial aneurysms: recurrence rates and incidence of late rebleeding

Object

Over a 16-year period, 570 patients presenting with acute aneurysmal subarachnoid hemorrhage were successfully treated using endosaccular coil embolization within 30 days of hemorrhage by a single surgeon. Patients were followed to assess the stability of aneurysm occlusion and its longer-term efficacy in protecting against rebleeding.

Methods

Patients were followed for 6 to 191 months (mean 73.7 months, median 67 months) by clinical review, angiography performed at 6 and 24 months posttreatment, and questionnaires sent via the postal service every 5 years. Late rebleeding was defined as > 30 days after treatment.

Results

Stable angiographic occlusion was evident in 74.5% of small, 72.2% of large, and 60% of giant aneurysms. Recurrent filling was found in 119 (26.3%) of 452 aneurysms. Rebleeding was diagnosed in 9 patients (6 treated aneurysms) and occurred between 2 and 114 months posttreatment. It was due to aneurysm recurrence in 6 patients, rupture of a coincidental untreated aneurysm in 2 patients, and rupture of a de novo aneurysm in 1 patient. Rebleeding occurred in 3 (2.5%) of 119 unstable aneurysms and in 3 (0.9%) of 333 stable aneurysms, as seen on initial follow-up angiography studies. Annual rebleeding rates ranged from 0.2% to 0.6% for all causes and from 0.2% to 0.4% for rebleeding of treated aneurysms. No rebleeding was recorded after the first decade, with 138 patients having more than 10 years of follow-up.

Conclusions

Periodic follow-up with angiographic studies after coil embolization is recommended to identify aneurysm recurrence and patients at a high risk of late rebleeding in the medium term. More frequent follow-up is recommended for patients harboring coincidental unruptured aneurysms.

Characteristics and management of residual or slowly recurred intracranial aneurysms

OBJECTIVE

Residual aneurysm from incomplete clipping or slowly recurrent aneurysm is associated with high risk of subarachnoid hemorrhage. We describe complete treatment of the lesions by surgical clipping or endovascular treatment.

METHODS

We analyzed 11 patients of residual or recurrent aneurysms who had undergone surgical clipping from 1998 to 2009. Among them, 5 cases were initially clipped at our hospital. The others were referred from other hospitals after clipping. The radiologic and medical records were retrospectively analyzed.

RESULTS

All patients presented with subarachnoid hemorrhage at first time, and the most frequent location of the ruptured residual or recurrent aneurysm was in the anterior communicating artery to posterior-superior direction. Distal anterior cerebral artery, posterior communicating artery, and middle cerebral artery was followed. Repositioning of clipping in eleven cases, and one endovascular treatment were performed. No residual aneurysm was found in postoperative angiography, and no complication was noted in related to the operations.

CONCLUSION

These results indicate the importance of postoperative or follow up angiography and that reoperation of residual or slowly recurrent aneurysm should be tried if such lesions being found. Precise evaluation and appropriate planning including endovascular treatment should be performed for complete obliteration of the residual or recurrent aneurysm.

Endovascular treatment of very small intracranial aneurysms

Object

Endovascular treatment of very small aneurysms poses a significant technical challenge for endovascular therapists. The authors review their experience with a series of patients who had intracranial aneurysms smaller than 3 mm in diameter.

Methods

Between 1995 and 2006, 97 very small aneurysms (defined for purposes of this study as < 3 mm in diameter) were diagnosed in 94 patients who were subsequently referred for endovascular treatment. All patients presented after subarachnoid hemorrhage, which was attributed to the very small aneurysms in 85 patients. The authors reviewed the endovascular treatment, the clinical and angiographic results of the embolization, and the complications.

Results

Five (5.2%) of the 97 endovascular procedures failed, and these patients underwent craniotomy and clip ligation. Of the 92 aneurysms successfully treated by coil embolization, 64 (69.6%) were completely occluded and 28 (30.4%) showed minor residual filling or neck remnants on the immediate postembolization angiogram. Complications occurred in 7 (7.2%) of 97 procedures during the treatment (3 thromboembolic events [3.1%] and 4 intraprocedural ruptures [4.1%]). Seventy-six patients were followed up angiographically; 4 (5.3%) of these 76 showed angiographic evidence of recanalization that required retreatment. The clinical outcomes for the 76 patients were also graded using the Glasgow Outcome Scale. In 61 (80.3%) cases the outcomes were graded 4 or 5, whereas in 15 (19.7%) they were graded 3. Seven patients (7.4%) died (GOS Grade 1), 2 due to procedure-related complications (intraoperative rupture) and 5 due to complications related to the presenting subarachnoid hemorrhage.

Conclusions

Endosaccular coil embolization of very small aneurysms is associated with relatively high rates of intraprocedural rupture, especially intraoperative rupture. With the advent of more sophisticated endovascular materials (microcatheters and microguidewires, soft and ultrasoft coils, and stents) endovascular procedures have become feasible and can lead to a good angiographic outcome.

International subarachnoid aneurysm trial of neurosurgical clipping versus endovascular coiling: subgroup analysis of 278 elderly patients

BACKGROUND AND PURPOSE

It is often thought that elderly patients in particular would benefit from endovascular aneurysm treatment. The aim of this analysis was therefore to compare the efficacy and safety of endovascular coiling (EVT) with neurosurgical clipping (NST) in the subgroup of elderly SAH patients in the International Subarachnoid Aneurysm Trial (ISAT).

METHODS

In the ISAT cohort 278 SAH patients, 65 years or older, were enrolled. The patients were randomly allocated EVT (n=138) or NST (n=140). The primary outcome was the proportion of patients with a modified Rankin scale score of 0 to 2 (independent survival) at 1 year after the SAH. The rates of procedural complications and adverse events were also recorded.

RESULTS

83 of 138 (60.1%) patients allocated EVT were independent compared to 78 of 140 (56.1%) allocated NST (N.S.). 36 of 50 (72.0%) patients with internal carotid and posterior communicating artery aneurysms allocated EVT were independent compared to 26 of 50 (52.0%) allocated NST (P<0.05). 10 of 22 (45.5%) patients with middle cerebral artery aneurysms allocated EVT were independent compared to 13 of 15 (86.7%) allocated NST (P<0.05). The epilepsy frequency was 0.7% in the EVT group compared to 12.9% in the NST group (P<0.001).

CONCLUSIONS

In good grade elderly SAH patients with small anterior circulation aneurysms, EVT should probably be the favored treatment for ruptured internal carotid and posterior communicating artery aneurysms, whereas elderly patients with ruptured middle cerebral artery aneurysms appear to benefit from NST. EVT resulted in a lower epilepsy frequency than NST.

Surgical decompression and coil removal for the recovery of vision after coiling and proximal occlusion of a clinoidal segment aneurysm: technical case report

OBJECTIVE

We present the case of a patient with continued deterioration of vision after endovascular treatment of an unruptured clinoidal segment aneurysm. In conjunction with a review of the literature, the findings in this case highlight the need for further refinements in our understanding of pathophysiological changes induced by coiling of cerebral aneurysms, especially those in aneurysms producing signs and symptoms relating to mass effect.

CLINICAL PRESENTATION

The patient is a 45-year-old man who presented with progressive vision loss. Imaging studies revealed a large, clinoidal segment aneurysm. The patient continued to experience progressive vision loss despite treatment with endovascular coiling, proximal occlusion, and high-dose steroid medication.

INTERVENTION

The patient underwent a craniotomy for decompression of the optic nerve and for salvage of vision. Clipping of the distal vessel was performed, and the coil mass was removed. The patient experienced marked improvement of central vision after the surgical procedure.

CONCLUSION

Although endovascular treatment of aneurysms protects most patients from aneurysm rupture, this case illustrates the fact that coiling, followed by proximal occlusion, might fail to alleviate symptoms related to mass effect. Our experience in this case suggests that early surgical decompression may be indicated for patients presenting with progressive visual deterioration.

Intravenous Administration of Acetylsalicylic Acid During Endovascular Treatment of Cerebral Aneurysms Reduces the Rate of Thromboembolic Events

Background and Purpose— The purpose of this study is to analyze the effect of a modified intraoperative anticoagulation strategy including acetylsalicylic acid (ASA) on complication rates during endovascular coil embolization.

Methods— Two hundred and sixty-one cerebral aneurysms were treated in 247 patients by endovascular coil embolization from January 2001 to September 2004. Additional intravenous administration of 250 mg ASA was applied since January 2003. Patients treated before (−ASA; n=102 aneurysms) and after that date (+ASA; n=159 aneurysms) were compared. End points were rates of thromboembolism and severity of hemorrhages after intraoperative aneurysm rupture.

Results— Thromboembolic events during the procedure were observed more often in the −ASA group (18/102 aneurysms, 17.6%) in comparison with the +ASA group (14/159 aneurysms, 8.8%; P =0.028; Fisher exact test). Aneurysm perforation events occurring during or immediately after the procedure were observed equally often in the −ASA group (7/102 aneurysms, 6.9%) in comparison with the +ASA group (10/159 aneurysms, 6.3%).

Conclusion— Intravenous application of ASA is feasible and safe during interventional aneurysm embolization. ASA seems to be associated with a significant reduction in the rate of thromboembolic events without increase in the rate or severity of intraoperative bleedings.

A longitudinal immunohistochemical study of the healing of experimental aneurysms after embolization with platinum coils

BACKGROUND AND PURPOSE

The purpose of this study was to probe the cellular mechanism of healing in aneurysms after platinum coil embolization, by using multiple special stains and immunolabels.

METHODS

Elastase-induced aneurysms were created and embolized in 28 rabbits. Aneurysms were excised between 2 and 24 weeks after embolization. Specimens were embedded in paraffin, sectioned, and stained with hematoxylin-eosin, Masson trichrome, and multiple immunostains.

RESULTS

At 2 weeks, peripheral sparse spindle-nucleated cells were positive for alpha-smooth muscle actin (SMA), myosin, and vimentin, indicating myofibroblastic differentiation. At 4 weeks, all spindle-nucleated cells in the aneurysm were positive for SMA, myosin, desmin, and vimentin. Ten weeks after embolization, positive immunohistochemical staining in the cells populating the aneurysm significantly decreased. Mean positive SMA cells, per high-powered field were 5 +/- 3, 45 +/- 9, 10 +/- 5, 0 +/- 0, and 0 +/- 0 at 2, 4, 10, 16, and 24 weeks, respectively. Findings of a Kruskal-Wallis test showed these data to be significantly different (P =.0001). Post hoc tests revealed significantly greater amounts of SMA-positive staining in the cells at 4 weeks compared with those at 2, 10, 16, and 24 weeks (P < .05). In addition, the 10-week group had significantly more positive cells than the 16- and 24-week groups (P < .05). There was a 78% decrease in apoptotic cells between 4 (37 +/- 11) and 10 weeks (8 +/- 4) after implantation. Apoptotic cells were completely absent beyond 10 weeks.

CONCLUSION

Aneurysm healing, in response to platinum coil embolization, appeared to progress through the stages of thrombus formation, granulated tissue organization, and loose connective tissue formation. Myofibroblasts, the key cellular component involved in healing, appeared within the aneurysm early. They progressively reduced in number with time and finally disappeared through the mechanism of apoptosis.

Midterm prevention of rebleeding by Guglielmi detachable coils in ruptured intracranial aneurysms less than 10mm

The midterm effects of coil embolization for ruptured aneurysm remain unknown. We investigated the prevention of rebleeding by GDC in ruptured aneurysms. Between March 1998 and April 2003, we treated 38 ruptured aneurysms measuring less than 10 mm in diameter. The patients were followed for a median of 37.3 months. During the follow-up term, aneurysms treated by coil embolization did not develop rebleeding after 1 month. We conclude that an embolized aneurysm measuring 10 mm or less remains quite stable over 3 years.

[Acutely ruptured intracranial aneurysms treated with GDC coils. Results from a single center over a period of 5 years]

PURPOSE

We prospectively reviewed the clinical results of acutely ruptured cerebral aneurysms treated with GDC over a 5 year period, in order to characterize death and dependency factors.

METHODS

Between 1997 and 2002, 229 patients (254 aneurysms treated, 140 females, 89 males; mean age: 51 years) with aneurysmal subarachnoid hemorrhage were treated with GDC (Boston Scientific Neurovascular, Fremont, CA) once the anatomical conditions of feasibility had been achieved. Over 90% of the aneurysms treated (mean size: 5,8 mm) were located in the anterior circulation. The anterior communicating artery complex (87 cases), the posterior aspect of the internal carotid artery (65 cases), and the middle cerebral artery (49 cases) were most commonly treated.

RESULTS

At the end of the initial hospitalization period, 14 patients (6.1%) died. Major procedural complications were associated with perforation of the aneurysmal sac in 9 patients (3.9%), thromboembolic events in 10 patients (4.3%) which resulted in 2 deaths (0.8%) and permanent neurologic morbidity in 7 patients (3%). The univariate analysis demonstrated no correlation between death and time-to-treatment, the topography of the aneurysm, or the occurrence of treatment related complications. The results of the logistical regression model demonstrated that the clinical score upon entry, and the occurrence of delayed ischemia were the only independent factors correlated with patient death. The prognostic factors affecting the degree of sequellae identified by the logistical regression model were the clinical score upon admission, age, treatment related complications, and pulmonary complications.

CONCLUSIONS

Endovascular treatment of ruptured anterior circulation aneurysms with GDC, including MCA aneurysms, is associated with low morbidity and allows good overall outcomes in patients with subarachnoid hemorrhage. A better understanding of dependency factors associated with endovascular coiling will foster further technical advances in order to improve the treatment of small and medium sized ruptured aneurysms.

Aneurysmal Rupture During Coiling: Low Incidence and Good Outcomes at a Single Large Volume Center

OBJECTIVE:

To study the incidence and clinical outcomes of intraoperative aneurysm rupture (IOR) during endovascular coil embolization at a single large volume center and to review the literature on this subject to determine whether IOR rupture rate and mortality correlate with volume of aneurysms treated at a given center and years since the institution of Guglielmi detachable coils as a treatment modality.

METHODS:

We reviewed the aneurysm database at the Center for Endovascular Surgery since its inception (1997–2003) and reviewed 600 consecutively treated intracranial aneurysms in which coiling was attempted. All patients who sustained an IOR were studied. Procedural and follow-up angiograms as well as clinical outcomes were retrospectively reviewed. A literature review was conducted.

RESULTS:

Six patients (1.0%) experienced IOR (1.4% in acutely ruptured lesions, 0% in unruptured). All six had presented with diffuse subarachnoid hemorrhage (Fisher Grade 3) and in good clinical grade (Hunt & Hess Grades 1–3). One patient was rendered permanently disabled secondary to delay in controlling the IOR. All others were neurologically unchanged. A review of the literature revealed a trend in correlation between volume of aneurysms treated and IOR rate; no statistically significant correlation was found between volume of aneurysms treated or years since the introduction of GDC technology and IOR rates or mortality.

CONCLUSION:

IOR remains a serious risk of endosaccular coiling of intracranial aneurysms, with aneurysms presenting with subarachnoid hemorrhage at greater risk for this complication. This risk can be minimized with very low associated morbidity and mortality (incidence 1%, 17% morbidity, 0% mortality at our institution).

Time-of-flight magnetic resonance angiography in the follow-up of intracranial aneurysms treated with Guglielmi detachable coils

The purpose of this study was to evaluate time-of-flight magnetic resonance angiography (MRA) in the follow-up of intracranial aneurysms treated with Guglielmi detachable coils (GDCs). From January 1998 to January 2002 27 MRA and intra-arterial digital subtraction angiography (IADSA) examinations were analyzed for residual aneurysms and arterial patency following GDC placement. A total number of 33 intracranial aneurysms was analyzed, including 18 located in the posterior circulation. The MRA analysis was based on source images in combination with maximum intensity projections. The IADSA was used as the reference standard. Two aneurysms were excluded from evaluation, because of susceptibility artefacts from other aneurysms, which were clipped. Sensitivity and positive predictive values of MRA in revealing residual aneurysms were, respectively, 89% and 80%. Specificity in ruling out remnant necks and residual flow around coils was, respectively, 91% and 97%, with a negative predictive value of, respectively, 95% and 100%. Specificity and negative predictive value of MRA for arterial occlusion were, respectively, 87% and 100% for the parent arteries and, respectively, 85% and 100% for the adjacent arteries. MRA is a reliable diagnostic tool in the follow-up of GDC treatment, and it may replace IADSA in excluding residual flow around coils and aneurysmal necks and in ruling out arterial occlusion.

Periprocedural morbidity and mortality associated with endovascular treatment of intracranial aneurysms

BACKGROUND AND PURPOSE

Despite experience and technological improvements, endovascular treatment of intracranial aneurysms still has inherent risks. We evaluated cerebral complications associated with this treatment.

METHODS

From October 1998 to October 2002, 180 consecutive patients underwent 131 procedures for 118 ruptured aneurysms and 79 procedures for 72 unruptured aneurysms. We retrospectively reviewed their records and images to evaluate their morbidity and mortality.

RESULTS

Thirty-seven (17.6%) procedure-related complications occurred: 27 and six with initial embolization of ruptured and unruptured aneurysms, respectively, and four with re-treatment. Complications included 22 cerebral thromboembolisms, nine intraprocedural aneurysm perforations, two coil migrations, two parent vessel injuries, one postprocedural aneurysm rupture, and one cranial nerve palsy. Fourteen complications had no neurologic consequence. Three caused transient neurologic morbidity; 10, persistent neurologic morbidity; and 10, death. Procedure-related neurologic morbidity and mortality rates, respectively, were as follows: overall, 4.8% and 4.8%; ruptured aneurysms, 5.9% and 7.6%; unruptured aneurysms, 1.4% and 1.4%; and re-treated aneurysms, 10% and 0%. Combined procedure-related morbidity and mortality rates for ruptured, unruptured, and re-treated aneurysms were 13.5%, 2.8%, and 10%, respectively. Nonprocedural complications attributable to subarachnoid hemorrhage in 118 patients with ruptured aneurysm were early rebleeding before coil placement (0.9%), symptomatic vasospasm (5.9%), and shunt-dependent hydrocephalus (5.9%); mortality from complications of subarachnoid hemorrhage itself was 11.9%.

CONCLUSION

Procedural morbidity and mortality rates were highest in ruptured aneurysms and lowest in unruptured aneurysms. Morbidity rates were highest in re-treated aneurysms and lowest in unruptured aneurysms. No procedural mortality occurred with re-treated aneurysms. The main cause of morbidity and mortality was thromboembolism.

Additional coiling of previously coiled cerebral aneurysms: clinical and angiographic results

BACKGROUND AND PURPOSE

Some cerebral aneurysms that have been coiled reopen over time and additional treatment should be considered to reduce the risk of recurrent hemorrhage. Our purpose was to assess procedural complications and angiographic results of additional coiling in patients with previously coiled but reopened aneurysms and to evaluate protection against (re)bleeding.

METHODS

We compared procedural complications of initial coiling of 488 aneurysms in 439 patients with those of 53 additional coiling procedures in 41 reopened aneurysms in 40 patients. Angiographic results of additional coiling were assessed. We compared episodes of (re)bleeding in patients with complete or near-complete aneurysm occlusion after additional coiling with those of patients with incomplete aneurysm occlusion at 6-month follow-up angiography who were not additionally treated or who still had incomplete occlusion after additional coiling.

RESULTS

Thirty-five procedural complications occurred in 488 initial coiling procedures, and no complications occurred in 53 additional procedures. Complete or near-complete angiographic occlusion after additional coiling was obtained in 31 (76%) of 41 aneurysms. Rebleeding occurred in two of 29 patients with incomplete aneurysm occlusion but in none of the 31 patients with complete or near-complete occlusion after additional coiling.

CONCLUSION

Additional coiling of previously coiled aneurysms has a low procedural complication rate and leads to sufficient occlusion in most aneurysms. The data indicate that successful additional coiling decreases the risk of rebleeding.

Les ruptures anévrismales intracrâniennes per-embolisation

OBJECTIVE

The purpose of this study is to determinate the frequency, causes, management and outcome of aneurysmal rupture occurring during embolization. We present our experience with this severe and feared complication.

METHODS

We retrospectively reviewed 314 acute cerebral aneurysms that were treated with endovascular coiling. These patients were identified and the management and outcomes were recorded. The literature was reviewed.

RESULTS

Six patients had an intraprocedural aneurysmal rupture. This complication occurred sporadically. Prevalence was 1.9%. Of these six, four were women and two were men. The mean age was 68 years (range: 43-74 years). Four aneurysms were located in the anterior circulation and two in the posterior circulation. Perforation occurred during microcatheterization of the aneurysm in one case and during coil deposition in five cases. In these five patients, aneurysmal rupture resulted from detachment of the first coil in three patients and detachment of the third and last coil in two patients. Hemodynamic changes were noted for one patient. The Glasgow Outcome Scale score at last follow-up examination was 1 in three patients and 3 in one patient (fair recovery). Mortality was 33% and morbidity was 16.7%.

CONCLUSION

Aneurysmal perforation during embolization is a rare event (1.8 to 4.4%). When perforation is recognized, embolization can be completed immediately with further coil deposition and reversal of anticoagulation therapy.

Anatomically conformable, three-dimensional, detachable platinum microcoil system for the treatment of intracranial aneurysms

BACKGROUND AND PURPOSE

The configurations of detachable platinum coils have evolved over the last decade. Our objective was to assess the efficacy of the anatomically conformable three-dimensional (ACT) detachable platinum microcoil in the treatment of intracranial aneurysms.

METHODS

A series of 141 patients presented between May 2000 and August 2002 to a single neurointerventionalist for endovascular treatment of intracranial aneurysms. Eight patients were treated at another institute or are now overseas. The remaining 133 patients had 141 aneurysms, which were treated; 110 were ruptured and 31 were unruptured. The clinical conditions and aneurysm locations were recorded. The procedural technique was the same as that used with the Guglielmi detachable coil (GDC) device, though the coil detachment mechanism was unique. The ACT microcoil was used in almost all cases as the initial coil.

RESULTS

Complete (100%) occlusion was achieved in 104 (74%) aneurysms. Thirty four (24%) had subtotal occlusion > or = 95%), and three (2%) had incomplete occlusion (<95%). The ACT coil conformed to both spherical and irregularly shaped aneurysms. No procedure-related deaths occurred, and there was no aneurysm rupture related to coil deployment. No postprocedural rebleeding was observed.

CONCLUSION

The ACT microcoil device is feasible as an alternative platinum coil device, offering some advantages over other currently available devices.

Treatment of intracerebral hematomas caused by aneurysm rupture: coil placement followed by clot evacuation

OBJECT

The aim of this study was to evaluate the efficacy of a treatment combination of coil embolization and clot evacuation in patients presenting with an intracerebral hematoma (ICH) caused by the rupture of an aneurysm.

METHODS

Twenty-seven patients were prospectively recruited in this study between 1996 and 2000. Endovascular treatment of the putative ruptured aneurysm was performed as soon as practical after diagnosis and before surgical evacuation of the ICH. The Glasgow Outcome Scale (GOS) was used during follow up. Despite admission World Federation of Neurosurgical Societies grades of IV or V in 25 patients (92%), 13 (48%) recovered well with GOS scores of 1 or 2, whereas six patients (21%) died.

CONCLUSIONS

The combined result of a favorable outcome in 48% of the patients and a mortality rate of 21% indicates that this treatment may be a valuable alternative for this patient group and warrants further study.

Endovascular treatment of ruptured intracranial aneurysms with detachable coils: long-term clinical and serial angiographic results

PURPOSE

To evaluate the stability of aneurysm occlusion over time, the need for additional treatments, and the long-term clinical outcome of patients, with emphasis on late recurrences of bleeding.

MATERIALS AND METHODS

The records of 160 patients with aneurysmal subarachnoid hemorrhage who were treated with coils were retrospectively reviewed. Follow-up angiography was performed 6 and 18 months after coil placement, and the results were classified as complete, near complete, and incomplete occlusion.

RESULTS

Six (4%) of the 160 patients experienced procedural mortality or dependency. After a mean follow-up of 36 months, 134 (84%) patients had a good outcome. Outcome was independent of aneurysm size and location and timing of treatment. Reopening of the aneurysm occurred exclusively during the first 6 months after coil placement, mainly in aneurysms larger than 15 mm. Between 6 and 18 months, no change in aneurysm occlusion was observed. Additional coil placement was performed in 15 (9%) patients. After this second coil placement, nine (7%) aneurysms were still incompletely occluded. Additional therapy was performed in eight (5%) patients. Two recurrences of bleeding were observed in two incompletely occluded large aneurysms. No recurrences of bleeding occurred in patients with completely or near completely occluded aneurysms.

CONCLUSION

Coil placement is an effective and safe treatment strategy for patients with aneurysmal subarachnoid hemorrhage. If aneurysm occlusion is sufficient at 6 months, the yield of further follow-up angiography is very low.

Post-mortem pathological examination of two patients after intraaneurysmal embolization using guglielmi detachable coils

SUMMARY

We report the histological findings in two patients treated using Guglielmi detachable coils with almost complete occlusion of the aneurysms.Autopsies of these patients were performed one week and one year after GDC embolization respectively. In one aneurysm that was obtained at autopsy one week after embolization, the histological findings revealed coils and an unorganized thrombus-filled aneurysm sac; an incomplete cell-lining on the luminal side of fibrin thrombi in the region of the neck of the aneurysm was recognized. In the other aneurysm in which autopsy was performed one year after embolization, an organized fibrous tissue at the margin of the aneurysmal wall and vascular granulation tissue at the center of the aneurysm were observed. There is a single layer of endothelium covering fibrous tissue in the neck of the aneurysm. We discuss the healing process after GDC treatment.

Surgical management of previously coiled intracranial aneurysms

With the increased use of endovascular therapy in the treatment of ruptured intracranial aneurysms the number of incompletely coiled aneurysms presenting for further management either due to lack of universal durability of this method or due to recurrent rupture is increasing. Since 1998, seven patients with previously coiled aneurysms underwent surgical obliteration of refractory or recurrent lesions. All patients were recorded in a prospective registry. Indications for surgery, the surgical techniques used and patient outcome were analysed. Surgery of recurrent or residual aneurysms resulted in a good outcome in four and a moderate outcome in one patient. Despite early clipping after recurrent haemorrhage after coil occlusion one of the two patients died, the other one had a moderate outcome. Our experience indicates that good results are obtainable, although technical challenges are frequently encountered.

Factors Leading to and Treatment of Aneurysmal Perforation during Coil Embolization. Analysis of 105 Consecutive Cases

SUMMARY

It is important to know the characteristics of aneurysms that tend to cause perforation and treatment of these perforations to reduce the morbi/mortality of the endovascular treatment for intracranial aneurysms. Factors leading to aneurysmal perforation were analyzed from the view points of aneurysmal status (ruptured or unruptured), size and direction of aneurysmal dome from the parent artery and treatment of perforation during GDC embolization was discussed in 105 consecutive cases. Perforation occurred in three small aneurysms (less than 3 mm in diameter or depth) where the direction of the dome is the same as that of microcatheter advancement. Perforation occurred when a microcatheter was advanced to counteract catheter recoil caused by coil deployment. Haemorrhage occurred in all cases immediately following microcatheter and coil perforation into the subarachnoid space. In all cases, bleeding was controlled by deploying the coil so that it extended from the subarachnoid space back into the intraaneurysmal cavity. In two cases, surgical clipping was required to treat the incompletely obliterated aneurysm. No additional permanent neurological deficit occurred as a result of any of the three perforations. Special care should be taken during the embolization of small aneurysms (less than 3 mm in minimal diameter) where, owing to the shape of the lesion, or fixation of a microcatheter by the stent strut, the antegrade force of the canulating microcatheter is transmitted directly toward the aneurysm dome.

Seizures after aneurysmal subarachnoid hemorrhage treated with coil embolization

OBJECTIVE

We sought to determine the incidence of seizures among patients treated with endovascular coil embolization for ruptured intracranial aneurysms because data on which to base antiepileptic drug (AED) prescriptions and advice to patients regarding driving motor vehicles and other high-risk activities are currently lacking.

METHODS

We conducted a single-institute, single-operator observational study of 243 patients referred for endovascular treatment after aneurysmal subarachnoid hemorrhage. Prospective data collection was performed, and all successfully treated patients were followed. The incidence of seizures was compared with published surgical data, and logistic regression analysis of potential clinical associations was performed. Patients were followed for up to 7.7 years (mean follow-up period, 21.9 mo).

RESULTS

Ictal seizures occurred at the time of subarachnoid hemorrhage in 26 (11%) of 243 patients and correlated with middle cerebral artery aneurysm location, loss of consciousness at ictus, and AED prescription. No patients experienced periprocedural seizures during their hospitalization. Seven of 233 successfully treated patients (3%) experienced seizures more than 30 days after treatment: late seizures occurred de novo in four patients (1.7%) and in three patients (1.4%) were caused by preexisting epilepsy. Two patients (0.85%) who had de novo seizures developed epilepsy. Late seizures correlated with a history of previous seizures, the presence of a cerebrospinal fluid shunt, and the use of AEDs.

CONCLUSION

The low incidence of seizures does not justify the use of prophylactic AED therapy after aneurysmal subarachnoid hemorrhage in patients treated solely with coil embolization, nor does it justify subsequent restrictions on the driving of motor vehicles if the patient is otherwise fit to drive.

Neurosurgical management of intracranial aneurysms previously treated with endovascular therapy

OBJECTIVE

With the increased use of endovascular therapy, an increasing number of patients with incompletely treated intracranial aneurysms are presenting for further surgical management. This study reviews our experiences with such patients.

METHODS

During a 7-year period, 38 patients with 40 intracranial aneurysms who were initially treated with endovascular therapy underwent surgical obliteration of refractory or recurrent lesions. All patients were recorded in a prospective registry, and their clinical data and imaging studies were analyzed retrospectively.

RESULTS

Twenty-six anterior and 14 posterior circulation aneurysms were treated. Four aneurysms were on the cavernous internal carotid artery, 13 were on the distal internal carotid artery, 6 were on the anterior communicating artery complex, 2 were on the middle cerebral artery, 3 were on the posteroinferior cerebellar artery, 1 was at the vertebrobasilar junction, 3 were on the superior cerebellar artery, 4 were at the basilar apex, 2 were on the posterior cerebral artery, and 1 was on the distal vertebral artery. Two pseudoaneurysms-one on the petrocavernous segment of the internal carotid artery and one on the distal VA-also were treated. The median time until recurrence was 6 months. Thirty-one aneurysms were clip-ligated, and six were treated with trapping. Three extracranial-intracranial bypasses were performed. One aneurysm was treated with muslin wrapping. Two aneurysms required the use of surgical approaches that involved hypothermic circulatory arrest. Nine aneurysms required coil mass extraction and/or complex vascular reconstruction to complete lesion obliteration. All aneurysms except the single wrapped aneurysm were successfully excluded from the intracranial circulation. Two deaths occurred as a result of the operative procedures, and another patient died as a result of subarachnoid hemorrhage-induced massive myocardial infarction. Ultimately, 86.8% of patients achieved an excellent or good recovery.

CONCLUSION

With endovascular therapy assuming an increasing role in the treatment of patients with intracranial aneurysms, more lesions that are refractory to initial treatment will require surgical management. Our experience indicates that good results are attainable, although technical challenges are frequently encountered.

Cerebral aneurysm perforations complicating therapy with Guglielmi detachable coils: a meta-analysis

BACKGROUND AND PURPOSE

The risk of intraprocedural aneurysm perforation in patients with previously ruptured aneurysms tends to be higher than that of patients with previously unruptured aneurysms, but a statistically significant difference has not been shown. Our purpose was to define the rates of occurrence and of morbidity and mortality associated with aneurysmal perforation associated with coil embolization.

METHODS

A meta-analysis of the results from 17 published retrospective reports of aneurysm perforations complicating therapy with Guglielmi detachable coils (GDCs) was performed. Rates of perforation and associated morbidity and mortality in previously ruptured and unruptured aneurysms were calculated. The mechanism of perforation was noted.

RESULTS

The risk of intraprocedural perforation was significantly higher in patients with ruptured aneurysms compared with patients with unruptured aneurysms (4.1% vs 0.5%; P <.001). The combined risk of permanent neurologic disability and death associated with intraprocedural aneurysm perforation was 38% for ruptured aneurysms and 29% for unruptured aneurysms. The morbidity and mortality rates with perforations caused by coils (39%) and microcatheters (33%) were similar. The morbidity and mortality rate for microguidewire perforations was considerably lower (0%, n = 4) than the rates for coils and microcatheters, but number of cases was too low to indicate statistical significance.

CONCLUSION

The risk of aneurysm perforation during GDC therapy is much higher in patients with previously ruptured aneurysms than in those with unruptured aneurysms. The morbidity and mortality rates are substantial for perforations caused by coils and microcatheters, whereas they seem to be much lower for perforations caused by microguidewires.

International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised trial

BACKGROUND

Endovascular detachable coil treatment is being increasingly used as an alternative to craniotomy and clipping for some ruptured intracranial aneurysms, although the relative benefits of these two approaches have yet to be established. We undertook a randomised, multicentre trial to compare the safety and efficacy of endovascular coiling with standard neurosurgical clipping for such aneurysms judged to be suitable for both treatments.

METHODS

We enrolled 2143 patients with ruptured intracranial aneurysms and randomly assigned them to neurosurgical clipping (n=1070) or endovascular treatment by detachable platinum coils (n=1073). Clinical outcomes were assessed at 2 months and at 1 year with interim ascertainment of rebleeds and death. The primary outcome was the proportion of patients with a modified Rankin scale score of 3-6 (dependency or death) at 1 year. Trial recruitment was stopped by the steering committee after a planned interim analysis. Analysis was per protocol.

FINDINGS

190 of 801 (23.7%) patients allocated endovascular treatment were dependent or dead at 1 year compared with 243 of 793 (30.6%) allocated neurosurgical treatment (p=0.0019). The relative and absolute risk reductions in dependency or death after allocation to an endovascular versus neurosurgical treatment were 22.6% (95% CI 8.9-34.2) and 6.9% (2.5-11.3), respectively. The risk of rebleeding from the ruptured aneurysm after 1 year was two per 1276 and zero per 1081 patient-years for patients allocated endovascular and neurosurgical treatment, respectively.

INTERPRETATION

In patients with a ruptured intracranial aneurysm, for which endovascular coiling and neurosurgical clipping are therapeutic options, the outcome in terms of survival free of disability at 1 year is significantly better with endovascular coiling. The data available to date suggest that the long-term risks of further bleeding from the treated aneurysm are low with either therapy, although somewhat more frequent with endovascular coiling.

Endovascular Treatment of Cerebral Aneurysms

Balloon occlusion of parent vessel and direct coiling are the two endovascular techniques routinely used and commonly accepted as alternatives to surgery for treatment of the cerebral aneurysm in many patients. Based on our experience and what is reported in the literature, the various aspects concerning techniques, difficulties, risks, are described. In comparison to surgery, the endovascular approach is a relatively new technique, which is still in evolution. To date, there is no objective indication regarding the method to be used in a given case. The experience and attitude of the involved team still play an essential role.

Clinical and radiographic outcome in the management of posterior circulation aneurysms by use of direct surgical or endovascular techniques

OBJECTIVE

Posterior circulation aneurysms can be difficult lesions to treat surgically, and they have potential for high morbidity and mortality, particularly in elderly patients or those in poor neurological condition. In an effort to improve outcomes, our combined neurosurgical and neuroendovascular unit has used both surgical clipping and endovascular coiling techniques to treat posterior circulation aneurysms. Patients considered at high risk for surgery were managed with endovascular treatment.

METHODS

From 1990 to 1998, 197 posterior circulation aneurysms in 189 patients were treated in our combined neurovascular unit. Of these aneurysms, 128 were ruptured, 63 were unruptured, and 6 had a distant history of rupture in patients who came to our center for delayed or repeat treatment. A total of 132 aneurysms were treated with surgical clipping (85 ruptured, 46 unruptured, and 1 with distant history of rupture) and 65 aneurysms were treated with endovascular coiling (43 ruptured, 17 unruptured, and 5 with distant history of rupture). Dissecting aneurysms of the vertebral or posteroinferior cerebellar arteries or aneurysms treated with proximal (Hunterian) occlusion were excluded from this analysis. Surgical risk was assessed using a previously described system (Massachusetts General Hospital [MGH] grade), which incorporates age, Hunt and Hess grade, size of lesion, and Fisher grade.

RESULTS

Overall clinical outcomes at 1 year of follow-up were 77.2% excellent or good, 10.2% fair, 4.1% poor, and 8.6% dead. Surgical treatment resulted in 95.6% complete aneurysm occlusion and 4.4% with residual aneurysm after surgical treatment, whereas endovascular treatment resulted in 32.3% complete occlusion, 26.2% with residual aneurysm, and 41.5% with partial occlusion. In most cases, however, treatment with Guglielmi detachable coils (Boston Scientific/Target, Fremont, CA) was performed for palliation rather than complete radiographic occlusion. Outcome was closely associated with MGH grade with either treatment modality. Excellent/good outcomes were achieved in 96, 92.3, 82.9, 46.2, and 0% of surgically treated patients with MGH Grades of 0, 1, 2, 3, and 4, respectively. In comparison, excellent/good outcomes were achieved in 100, 84.2, 61.9, 0, and 50% of endovascularly treated patients with MGH Grades of 0, 1, 2, 3, and 4, respectively.

CONCLUSION

A combined surgical and endovascular approach to posterior circulation aneurysms can achieve good outcomes in high-risk surgical patients treated by use of coiling techniques.

Endovascular therapy for intracranial aneurysms: a historical and present status review

Beginning in the 1960s, neurosurgeons and radiologists have made attempts to treat intracranial aneurysms using nonclip techniques. The evolution of such therapy has included acrylics, metallic particles, balloons, electric current, and nondetachable and detachable coils. This article will chronologically review these various techniques and the papers that reported their results so that the reader can understand how endovascular therapy developed and the position it currently holds in the treatment of intracranial aneurysms.

Treatment of ruptured intracranial aneurysms by embolization with controlled detachable coils

BACKGROUND

Neurosurgical clipping used to be the standard method of occluding intracranial aneurysms, but controlled detachable coils are increasingly used to obliterate aneurysms by endosaccular packing.

REVIEW SUMMARY

A systematic review of observational studies on embolization with coils showed in patients with a ruptured aneurysm a complete occlusion in 52% of aneurysms, independence at follow-up in 89% of patients, and a procedure related mortality of 1.1%. There is no consensus with regard to the indications for surgical or endovascular treatment. A recently published randomized trial on early coiling versus early operation did not show any differences in clinical outcome after 3 and 12 months, but the small number of patients included precludes firm conclusions. Comparisons between endovascular and surgical treatment should not only address safety and clinical outcome, but also the long-term angiographic results and the risk of recurrent hemorrhage after treatment. In current practice, many patients with a basilar bifurcation aneurysm are treated by embolization with coils. In many patients with a middle cerebral artery aneurysm operation is the preferred treatment. For all other aneurysm locations preference for coiling or clipping depends on the clinical condition of the patient, the configuration of the aneurysm, and on the experience and skills of the local endovascular and neurosurgical team.

CONCLUSIONS

Endovascular treatment of intracranial aneurysms has gained widespread acceptance. Preference for coiling or clipping depends on patient and aneurysm characteristics, and on the local expertise.

Outcomes after aneurysm rupture during endovascular coil embolization

OBJECTIVE

Intracranial aneurysm rupture during placement of Guglielmi detachable coils has been reported, but the management and consequences of this event have not been extensively described. We present our experience with this feared complication and report possible neuroradiological and neurosurgical interventions to improve outcomes.

METHODS

We retrospectively reviewed the records for 701 patients with 734 intracranial aneurysms that were treated with endovascular coiling, during a 6-year period, in the metropolitan Minneapolis-St. Paul (Minnesota) area. This analysis revealed 10 cases of perforation during coiling. The management and outcomes were recorded, and the pertinent literature was reviewed.

RESULTS

All 10 cases involved previously ruptured aneurysms. This complication occurred sporadically and was not observed in the first 100 cases. Perforation occurred during microcatheterization of the aneurysm in two cases and during coil deposition in eight cases. Seven of the perforated aneurysms were located in the anterior circulation and three in the posterior circulation. Six of the 10 patients made good or fair recoveries; all three patients with posterior circulation lesions died immediately after rehemorrhage. Elevated intracranial pressure (ICP) was noted for all five patients with intraventricular catheters in place. Bilateral pupil dilation and profound hemodynamic changes were noted for eight patients. Coiling was rapidly completed, and total or nearly total occlusion was achieved in all cases. Emergency ventriculostomy was performed to rapidly reduce increased ICP for two patients, both of whom made good recoveries. Hemodynamic and angiographic factors after perforation, such as prolonged systemic hypertension, persistent dye extravasation after deployment of the first Guglielmi detachable coil, and persistent prolongation of contrast dye transit time (suggesting ongoing ICP elevation), were correlated with poor outcomes.

CONCLUSION

Previously ruptured aneurysms seem to be more susceptible to endovascular treatment-related perforation than are unruptured lesions. Worse prognoses are associated with iatrogenic rupture during coiling of posterior circulation lesions, compared with those in the anterior circulation. When perforation is recognized, the definitive treatment seems to be reversal of anticoagulation therapy and completion of Guglielmi detachable coil embolization. Immediate neurosurgical intervention is limited in these cases and focuses on decreasing ICP via emergency ventriculostomy. However, these measures may be life-saving, and neurosurgical assistance must be readily available during treatment of these cases.