Complications of endovascular treatment of cerebral aneurysms

Evaluation of acute intraprocedural thromboembolism risk factors in endovascular treatment of unruptured intracranial aneurysms

BACKGROUND

Acute intraprocedural thromboembolism (AIT) is not a rare complication that usually occurs immediately after stent deployment during endovascular aneurysm treatment (EVAT).

METHODS

We retrospectively analyzed the 386 EVAT of 320 patients for the AIT occurrence between 2014 and 2018. The patient's comorbidities, aneurysm location, antiplatelet type, and thrombocyte reactivity to P2Y12 inhibitors were assessed. AIT severity was categorized as severe (hyperacute thrombus filling >50 % stent lumen) or mild (in-stent thrombus <50 %, side/integrated branch occlusion, or distal cortical branch occlusion). The EVAT was categorized on a location basis (proximal or distal), accounting for the terminal edges of the deployed stent.

RESULTS

30 (7.8 %) of 386 EVAT procedures were complicated with AIT. There were 9 (30 %) severe AIT and 21 (70 %) mild AIT, consisting of 12 (40 %) partial in-stent thrombi and 9 (30 %) distal cortical or side branch emboli. Patient comorbidities and type of antiplatelet regimen were not different between the AIT group and uncomplicated cases. Mild AIT was higher in the flow diversion (FD) versus stent-assisted coiling (SAC), (8.1 %, and 2.3 %, respectively, p = 0.012). Deployment of braided SAC (OR: 8.5, p = 0.04) or FD (OR: 18.8, p < 0.01) resulted in significantly higher AIT rates compared to laser-cut SAC. Additionally, stent placement in distal EVAT (beyond the ICA bifurcation or basilar apex) was associated with a significantly higher AIT risk (OR: 8.5, p < 0.01).

CONCLUSION

Patient comorbidities and type of antiplatelet regimen had no association with AIT when sufficient anti-aggregation was achieved. However, AIT risk surged with braid-SAC or FD, especially in the treatment of distal complex aneurysms.

Machine Learning Algorithms to Predict the Risk of Rupture of Intracranial Aneurysms: a Systematic Review

PURPOSE

Subarachnoid haemorrhage is a potentially fatal consequence of intracranial aneurysm rupture, however, it is difficult to predict if aneurysms will rupture. Prophylactic treatment of an intracranial aneurysm also involves risk, hence identifying rupture-prone aneurysms is of substantial clinical importance. This systematic review aims to evaluate the performance of machine learning algorithms for predicting intracranial aneurysm rupture risk.

METHODS

MEDLINE, Embase, Cochrane Library and Web of Science were searched until December 2023. Studies incorporating any machine learning algorithm to predict the risk of rupture of an intracranial aneurysm were included. Risk of bias was assessed using the Prediction Model Risk of Bias Assessment Tool (PROBAST). PROSPERO registration: CRD42023452509.

RESULTS

Out of 10,307 records screened, 20 studies met the eligibility criteria for this review incorporating a total of 20,286 aneurysm cases. The machine learning models gave a 0.66-0.90 range for performance accuracy. The models were compared to current clinical standards in six studies and gave mixed results. Most studies posed high or unclear risks of bias and concerns for applicability, limiting the inferences that can be drawn from them. There was insufficient homogenous data for a meta-analysis.

CONCLUSIONS

Machine learning can be applied to predict the risk of rupture for intracranial aneurysms. However, the evidence does not comprehensively demonstrate superiority to existing practice, limiting its role as a clinical adjunct. Further prospective multicentre studies of recent machine learning tools are needed to prove clinical validation before they are implemented in the clinic.

Coil Embolization for Cerebral Aneurysm Using Low Pulse Rate Fluoroscopy

Although coil embolization is commonly perceived as a minimally invasive procedure, the associated radiation exposure cannot be disregarded. To date, no specific study has investigated radiation exposure during coil embolization. This study aimed to investigate the potential of lowering the pulse rate to decrease radiation exposure during coil embolization while maintaining patient safety. Radiation data and clinical features of 70 patients who underwent coil embolization between 2015 and 2020 were retrospectively analyzed. Since July 2017, the pulse rate was regulated from 7.5 to 4 frames per second (f/s). Statistical analyses were performed to examine the correlation between pulse rate and radiation exposure. Out of the 70 procedures, 30 were performed at the standard pulse rate (7.5 f/s), and 40 were performed at the lower pulse rate (4 f/s). In the lower-pulse-rate group, the absorbed dose to the patient (AK) was 2580.7 (±217) mGy, whereas in the standard-pulse-rate group, it was 4760 (±411.1). Both the dose-area product (DAP) and AK were substantially reduced in the low pulse rate group (p = 0.000002). There was a significant correlation between DAP and AK and pulse rate (p = 0.004, p = 0.0017, respectively). Moreover, there was no significant correlation between pulse rate and perioperative complications. Our findings suggest that using a lower pulse rate (4 f/s) can effectively reduce radiation exposure during coil embolization for cerebral aneurysms while ensuring patient safety.

Complications of Endovascular and Open Aneurysm Surgery in the Era of Flow Diversion

The techniques used for treatment of intracranial aneurysms have progressed dramatically over the decades. The introduction of modern endovascular techniques and the continued refinement of progressively less invasive neurosurgical approaches have contributed to steadily improving clinical outcomes. Moreover, innovations such as flow-diverting stents have achieved dramatic success and have gained rapid widespread adoption. Particularly in lesions for which the application of conventional treatment techniques is difficult, flow diversion technology has revolutionized aneurysm management. This review provides a discussion on the morbidity and mortality encountered in the treatment of intracranial aneurysms in the modern era. Common adverse events faced in the management of these lesions with open surgery and various endovascular techniques are highlighted.

A Comparative Evaluation of Standard and Balloon-Assisted Coiling of Intracranial Aneurysms Based on Neurophysiological Monitoring

BACKGROUND AND PURPOSE

Intracranial aneurysms are commonly treated with balloon-assisted endovascular coiling because the balloon allows for the control und modulation of wide-necked aneurysms and the coil basket. However, this approach might be associated with a higher complication rate. This retrospective study compared the multimodal results between balloon-assisted coiling of aneurysms (group 1) and coiling without balloon assistance (group 2).

MATERIALS AND METHODS

We included 67 patients with unruptured intracranial aneurysms in this retrospective analysis; acutely ruptured aneurysms were excluded from the analysis. We divided these patients into two groups and evaluated them for symptomatic thromboembolic complications in the course of intracranial aneurysm treatment. All patients had an intrainterventional neurophysiological monitoring (IINM) and a pre- and postinterventional NIH Stoke Scale (NIHSS) survey and MR imaging. Multiple logistic regression was used to assess whether balloon-assisted coiling increased the rate of thromboembolic complications. Periprocedural aneurysm hemorrhage did not occur in any of the cases.

RESULTS

We detected no statistically significant difference in rates of neurophysiological disturbances (19.5% (group 1) versus 34.6% (group 2); p = 0.249). There was no association with age, gender, or aneurysm location. The occurrence of new diffusion-weighted defects was not statistically significantly different (19.5% (group 1) versus 35.0% (group 2); p = 0.166). The difference in NIHSS before and after the intervention showed also no statistical significance in both groups (p = 0.426).

CONCLUSION

The use of balloon-assisted coiling did not increase the rate of neurological disturbances during endovascular coiling. MR imaging and NIHSS survey also showed no increased risk of embolization from balloon-assisted aneurysm coiling. IINM is a central aspect of care during endovascular coiling as it can substantially decrease morbidity.

First in Man Pilot Feasibility Study in Extracranial Carotid Robotic-Assisted Endovascular Intervention

BACKGROUND

Robotic-assistance in endovascular intervention represents a nascent yet promising innovation.

OBJECTIVE

To present the first human experience utilizing robotic-assisted angiography in the extracranial carotid circulation.

METHODS

Between March 2019 and September 2019, patients with extracranial carotid circulation pathology presenting to Houston Methodist Hospital were enrolled.

RESULTS

A total of 6 patients met inclusion criteria: 5 underwent diagnostic angiography only with robotic-assisted catheter manipulation, while 1 underwent both diagnostic followed by delayed therapeutic intervention. Mean age was 51 +/- 17.5 yr. Mean anesthesia time was 158.7 +/- 37.9 min, mean fluoroscopic time was 22.0 +/- 7.3 min, and mean radiation dose was 815.0 +/- 517.0 mGy. There were no technical complications and no clinical deficits postprocedure. None of the cases required conversion to manual neurovascular intervention (NVI).

CONCLUSION

Incorporating robotic technology in NVI can enhance procedural technique and diminish occupational hazards. Its application in the coronary and peripheral vascular settings has established safety and efficacy, but in the neurovascular setting, this has yet to be demonstrated. This study presents the first in human feasibility experience of robotic-assisted NVI in the extracranial carotid circulation.

Long-Term Rupture Risk in Patients with Unruptured Intracranial Aneurysms Treated with Endovascular Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

Surveillance imaging of previously unruptured, coiled aneurysms remains routine even though reports of rupture of these aneurysms are extremely rare.

PURPOSE

We performed meta-analysis to examine long-term rupture risk over ≥1-year follow-up duration in patients with unruptured intracranial aneurysm who underwent endovascular therapy.

DATA SOURCES

Multiple databases were searched for relevant publications between 1995 and 2018.

STUDY SELECTION

Studies reporting outcome of long-term rupture risk over ≥1-year follow-up in treated patients with unruptured intracranial aneurysms were included.

DATA ANALYSIS

Random effects meta-analysis was used, and results were expressed as long-term rupture rate per 100 patient-year with respective 95% CIs. For ruptured aneurysms during follow-up, data were collected on size and completeness of initial Treatment.

DATA SYNTHESIS

Twenty-four studies were identified. Among 4842 patients with a mean follow-up duration of 3.2 years, a total of 12 patients (0.25%) experienced rupture of previous unruptured intracranial aneurysms after endovascular treatment. Nine of these 12 patients harbored aneurysms that were large, incompletely treated, or both. A total of 2 anterior circulation, small, completely coiled aneurysms subsequently ruptured. The long-term rupture rate per 100 patient-year for unruptured intracranial aneurysms treated with endovascular therapy was 0.48 (95% CI, 0.45-0.51). Retreatment was carried out in 236 (4.9%) of these 4842 patients.

LIMITATIONS

A limitation of the study is that a lack of systematic nature of follow-up and mean follow-up duration of 3.2 years are not sufficient to make general recommendations about aneurysm followup paradigms.

CONCLUSIONS

Given a 5% retreatment rate, postcoil embolization spontaneous rupture of previously unruptured, small- and medium-sized, well-treated aneurysms is exceedingly rare.

Mechanical thrombectomy for occlusion near a ruptured intracranial aneurysm: A case report

Background:

While recent randomized clinical trials have shown the efficacy of mechanical thrombectomy for acute large vessel anterior cerebral occlusion, cases in patients with a subarachnoid hemorrhage (SAH) were excluded from the study.

Case Description:

A 58-year-old man presented with a SAH as a result of a ruptured middle cerebral artery aneurysm. Coil embolization was performed, and a right intracranial angiography showed remnants of an aneurysmal neck. However, the following angiography also revealed a thromboembolic complication that occurred in the same territory as the ruptured aneurysm. The patient underwent a rescue mechanical thrombectomy under the working projection. We deployed a retrieval stent without covering the aneurysmal neck. The occluded vessel was recanalized without any hemorrhagic complication. Due to minimal intracerebral infarction, the patient had good outcomes.

Conclusion:

Mechanical thrombectomy is a useful option to retrieve a clot from an occluded intracranial vessel located near a ruptured aneurysm. Approaching the clot at the working projection is important to ensure safety in the setting of a ruptured aneurysm.

Advantages of Coil Embolization Performed Immediately After Diagnostic Cerebral Digital Subtraction Angiography in Unruptured Intracranial Aneurysms: Patients' Perspective

BACKGROUND

We are inevitably faced with the need to perform coil embolization immediately after diagnostic cerebral digital subtraction angiography (DSA) for economic reasons, patient convenience, fear of rupture, and other reasons. Here we report the advantages of coil embolization performed immediately after diagnostic cerebral DSA for unruptured intracranial aneurysms (UIAs) from the patients' perspective.

METHODS

Between January 2017 and October 2018, 145 patients were treated for UIAs with endovascular coil embolization at the Yeungnam University Medical Center. There were 87 patients in the group in which coil embolization was to be performed at least 1 week after diagnostic cerebral DSA (regular [R] group) and 58 patients in the group in which coil embolization was to be performed immediately after diagnostic cerebral DSA (immediate [I] group).

RESULTS

There were no statistically significant between group differences in any factor analyzed expect for medical expenses (out-of-pocket costs), 2,218,416 KRW (1963 USD) for the R group and 1,128,906 KRW (999 USD) for the I group (P < 0.001). There were no statistically significant differences in the rate of complications between the 2 groups, with 4 minor complications and 1 death in the R group and 3 minor complications and 1 death in the I group.

CONCLUSIONS

Our findings indicate that coil embolization performed immediately after diagnostic cerebral DSA can be a relatively safe alternative approach to treating patients with UIAs.

Pipeline embolization device versus coiling for the treatment of large and giant unruptured intracranial aneurysms: a cost-effectiveness analysis

OBJECTIVE Rupture of large or giant intracranial aneurysms leads to significant morbidity, mortality, and health care costs. Both coiling and the Pipeline embolization device (PED) have been shown to be safe and clinically effective for the treatment of unruptured large and giant intracranial aneurysms; however, the relative cost-to-outcome ratio is unknown. The authors present the first cost-effectiveness analysis to compare the economic impact of the PED compared with coiling or no treatment for the endovascular management of large or giant intracranial aneurysms. METHODS A Markov model was constructed to simulate a 60-year-old woman with a large or giant intracranial aneurysm considering a PED, endovascular coiling, or no treatment in terms of neurological outcome, angiographic outcome, retreatment rates, procedural and rehabilitation costs, and rupture rates. Transition probabilities were derived from prior literature reporting outcomes and costs of PED, coiling, and no treatment for the management of aneurysms. Cost-effectiveness was defined, with the incremental cost-effectiveness ratios (ICERs) defined as difference in costs divided by the difference in quality-adjusted life years (QALYs). The ICERs < $50,000/QALY gained were considered cost-effective. To study parameter uncertainty, 1-way, 2-way, and probabilistic sensitivity analyses were performed. RESULTS The base-case model demonstrated lifetime QALYs of 12.72 for patients in the PED cohort, 12.89 for the endovascular coiling cohort, and 9.7 for patients in the no-treatment cohort. Lifetime rehabilitation and treatment costs were $59,837.52 for PED; $79,025.42 for endovascular coiling; and $193,531.29 in the no-treatment cohort. Patients who did not undergo elective treatment were subject to increased rates of aneurysm rupture and high treatment and rehabilitation costs. One-way sensitivity analysis demonstrated that the model was most sensitive to assumptions about the costs and mortality risks for PED and coiling. Probabilistic sampling demonstrated that PED was the cost-effective strategy in 58.4% of iterations, coiling was the cost-effective strategy in 41.4% of iterations, and the no-treatment option was the cost-effective strategy in only 0.2% of iterations. CONCLUSIONS The authors' cost-effective model demonstrated that elective endovascular techniques such as PED and endovascular coiling are cost-effective strategies for improving health outcomes and lifetime quality of life measures in patients with large or giant unruptured intracranial aneurysm.

Procedure-related Complications during Endovascular Treatment of Intracranial Saccular Aneurysms

Objective

We evaluate the rates and outcomes of major procedure-related complications during coiling.

Materials and Methods

Between 2007 and 2015, 436 intracranial saccular aneurysms were treated. Complications are categorized as three types: intraprocedural aneurysm rupture (IAR), thromboembolism (TE), and post-procedural early rebleeding (PER). And we evaluated the risk factors of procedure related complications by multivariate analysis.

Results

Complications occurred in 61 aneurysms (14%). The overall incidence of complications in subarachnoid hemorrhage (SAH) was significantly higher than in unruptured intracranial aneurysm (UIA) (20% vs. 6%). The incidence of IAR and TE were higher in SAH than in UIA (IAR 12% vs. 4%, TE 7% vs. 3%, p < 0.05). Five PER occurred only in SAH. In 34 UIA which were treated with balloon-assisted coiling (BAC), all these patients had good recovery despite 3 patients had the IAR. The incidence of IAR and TE were not different between BAC and non-BAC groups (p > 0.05). All 7 patients who had IAR during BAC had good recovery. In multiple logistic regression analysis, female gender, SAH, and intraventricular hemorrhage were associated with procedure related complication (p < 0.05).

Conclusion

Endovascular coil embolization is a minimally invasive procedure, but incidence of its complication is not low, especially in SAH. BAC can be a good tool to avoid poor outcome from unexpected IAR during coiling. While IA tirofiban injection is a useful therapy in TE during coiling, sometimes we are aware of the risk of the early rebleeding in SAH patients.

Diagnostic Accuracy of Somatosensory Evoked Potential Monitoring in Evaluating Neurological Complications During Endovascular Aneurysm Treatment

BACKGROUND

Somatosensory evoked potential (SSEP) monitoring is used extensively for early detection and prevention of neurological complications in patients undergoing many different neurosurgical procedures. However, the predictive ability of SSEP monitoring during endovascular treatment of cerebral aneurysms is not well detailed.

OBJECTIVE

To evaluate the performance of intraoperative SSEP in the prediction postprocedural neurological deficits (PPNDs) after coil embolization of intracranial aneurysms.

METHODS

This population-based cohort study included patients ≥18 years of age undergoing intracranial aneurysm embolization with concurrent SSEP monitoring between January 2006 and August 2012. The ability of SSEP to predict PPNDs was analyzed by multiple regression analyses and assessed by the area under the receiver operating characteristic curve.

RESULTS

In a population of 888 patients, SSEP changes occurred in 8.6% (n = 77). Twenty-eight patients (3.1%) suffered PPNDs. A 50% to 99% loss in SSEP waveform was associated with a 20-fold increase in risk of PPND; a total loss of SSEP waveform, regardless of permanence, was associated with a greater than 200-fold risk of PPND. SSEPs displayed very good predictive ability for PPND, with an area under the receiver operating characteristic curve of 0.84 (95% CI 0.76-0.92).

CONCLUSION

This study supports the predictive ability of SSEPs for the detection of PPNDs. The magnitude and persistence of SSEP changes is clearly associated with the development of PPNDs. The utility of SSEP monitoring in detecting ischemia may provide an opportunity for neurointerventionalists to respond to changes intraoperatively to mitigate the potential for PPNDs.

Complications of Neurosurgery

PURPOSE OF REVIEW

This article provides an overview of the major neurologic complications of common neurosurgical and endovascular procedures.

RECENT FINDINGS

Brain edema, seizures, postoperative hemorrhage, and cerebral ischemia can complicate neurosurgical procedures and produce neurologic decline. The high variability of reporting, types of operations, patient characteristics, and acuity of cases make estimating the incidence and severity of complications difficult. Overall, the complication rate of neurosurgical procedures is approximately 14%, but these are commonly systemic complications (eg, bleeding requiring transfusion, need for mechanical ventilation). In addition to intracranial hemorrhage, ischemia, and seizures after craniotomies, additional characteristic complications include hyperperfusion syndrome and cranial nerve palsies after carotid endarterectomy, cerebrospinal fluid leaks and aseptic meningitis after posterior fossa surgery, and arterial dissections or groin hematomas after endovascular procedures.

SUMMARY

Neurologic decline can be caused by a variety of causes in the postoperative period. The indication for surgery, type of surgery, and time of decline is helpful in narrowing the differential diagnosis. Brain edema, elevated intracranial pressure (ICP), seizures, intracranial hemorrhage, ischemic infarction, and cranial nerve palsies are some of the more common complications in patients that neurologists may be asked to evaluate or comanage in the postoperative setting.

Angiographic and Clinical Results after Endovascular Treatment for Middle Cerebral Artery Berry Aneurysms

Sixty-five middle cerebral artery (MCA) aneurysms in 59 patients treated by endovascular treatment (EVT) without the remodelling technique were analyzed. For ruptured aneurysms, the patients in bad condition are predominant and those with Fisher group four is 47.8% and with Hunt and Hess grade (HHG) IV or V are 43.5%. The clinical result is that 58.7% is in mRS 0–3, 21.7% in 4–5 and 19.6% in death. Contrary, 92.3% of the patients in HHG I-III resulted in mRS 0–3. Re-rupture was observed in two cases (4.4%). For all the aneurysms, thromboembolic complications were observed in 12.3% and those were predominant in the aneurysms greater than 10mm in diameter (p<0.05). Hemorrhagic ones occurred in 6.2% which were predominant in the aneurysms less than 10mm in diameter. No mortality was observed by the accidents. In follow-up angiography, Raymond classification was employed and Complete Obliteration or Dog Ear was observed in 24 of 43 cases (55.8%). Recanalization occurred in 10.5% of the cases with complete or almost complete obliterated aneurysms. These results suggested that EVT for the ruptured MCA aneurysms with good grade or the unruptured ones is feasible. Strict follow-up is important like the other aneurysms.

Clinical Presentation, Imaging, and Management of Complications due to Neurointerventional Procedures

Neurointervention is a rapidly evolving and complex field practiced by clinicians with backgrounds ranging from neurosurgery to radiology, neurology, cardiology, and vascular surgery. New devices, techniques, and clinical applications create exciting opportunities for impacting patient care, but also carry the potential for new iatrogenic injuries. Every step of every neurointerventional procedure carries risk, and a thorough appreciation of potential complications is fundamental to maximizing safety. This article presents the most frequent and dangerous iatrogenic injuries, their presentation, identification, prevention, and management.

Thromboembolic events associated with single balloon-, double balloon-, and stent-assisted coil embolization of asymptomatic unruptured cerebral aneurysms: evaluation with diffusion-weighted MR imaging

INTRODUCTION

The introduction of the balloon remodeling and stent-assisted technique has revolutionized the approach to coil embolization for wide-neck aneurysms. The purpose of this study was to determine the frequency of thromboembolic events associated with single balloon-assisted, double balloon-assisted, and stent-assisted coil embolization for asymptomatic unruptured aneurysms.

METHODS

A retrospective review was undertaken by 119 patients undergoing coiling with an adjunctive technique for unruptured saccular aneurysms (64 single balloon, 12 double balloon, 43 stent assisted). All underwent diffusion-weighted imaging (DWI) within 24 h after the procedure.

RESULTS

DWI showed hyperintense lesions in 48 (40%) patients, and ten (21%) of these patients incurred neurological deterioration (permanent, two; transient, eight). Hyperintense lesions were detected significantly more often in procedures with the double balloon-assisted technique (7/12, 58%) than with the single balloon-assisted technique (16/64, 25%, p = 0.05). Occurrence of new lesions was significantly higher with the use of stent-assisted technique (25/43, 58%) than with the single balloon-assisted technique (p = 0.001). Symptomatic ischemic rates were similar between the three groups. The increased number of microcatheters was significantly related to the DWI abnormalities (two microcatheters, 15/63 (23.8%); three microcatheters, 20/41 (48.8%) (p = 0.008); four microcatheters, 12/15 (80%) (p = 0.001)).

CONCLUSION

Thromboembolic events detected on DWI related to coil embolization for unruptured aneurysms are relatively common, especially in association with the double balloon-assisted and stent-assisted techniques. Furthermore, the number of microcatheters is highly correlated with DWI abnormalities. The high rate of thromboembolic events suggests the need for evaluation of platelet reactivity and the addition or change of antiplatelet agents.

Angiographic and clinical result of endovascular treatment in paraclinoid aneurysms

Purpose

The purpose of this study was to analyze the results of an immediate and mid-term angiographic and clinical follow-up of endovascular treatment for paraclinoid aneurysms.

Materials and Methods

From January 2002 to December 2012, a total of 113 consecutive patients (mean age: 56.2 years) with 116 paraclinoid saccular aneurysms (ruptured or unruptured) were treated with endovascular coiling procedures. Clinical and angiographic outcomes were retrospectively evaluated.

Results

Ninety-three patients (82.3%) were female. The mean size of the aneurysm was 5.5 mm, and 101 aneurysms (87.1%) had a wide neck. Immediate catheter angiography showed complete occlusion in 40 aneurysms (34.5%), remnant sac in 51 (43.9%), and remnant neck in 25 (21.6%). Follow-up angiographic studies were performed on 80 aneurysms (69%) at a mean period of 20.4 months. Compared with immediate angiographic results, follow-up angiograms showed no change in 38 aneurysms, improvement in 37 (Fig. 2), and recanalization in 5. There were 6 procedure-related complications (5.2%), with permanent morbidity in one patient.

Conclusion

Out study suggests that properly selected patients with paraclinoid aneurysms can be successfully treated by endovascular means.

Treatment of patients with ruptured aneurysm by neurosurgeons that perform both open surgical and endovascular techniques is safe and effective: results of a single centre in Europe

In Europe only few neurosurgeons are trained in both open surgical clipping as well as in endovascular techniques for treatment of intracranial aneurysms. To investigate the safety and efficacy of performing both techniques we, two dual trained neurosurgeons, analyzed our results in repairing ruptured intracranial aneurysms. Prospectively collected data from 356 patients that underwent open surgical or endovascular repair of a ruptured intracranial aneurysm at the Neurosurgical Centre Nijmegen from 2006 to 2012 by two dual trained neurosurgeons were retrospectively analyzed. Complication rates, occlusion rates, and retreatment rates were obtained. Combined procedural persistent neurological morbidity and mortality after endovascular treatment and open surgical clipping were 2.1 % and 1.4 %, respectively. Overall procedure-related clinical complication rate for endovascular treatment was 5.9 % in 285 procedures for 295 aneurysms. Overall procedure-related clinical complication rate for open treatment was 9.9 % in 71 procedures for 72 aneurysms. Follow-up was available for 255 out of 295 coiled aneurysms, 48 aneurysms recurred and 34 needed retreatment. For clipping 54 out of 72 treated aneurysms had follow-up; four aneurysms were incompletely clipped. One aneurysm was retreated. Treatment of ruptured intracranial aneurysms by neurosurgeons that perform both open surgical clipping as well as endovascular techniques is safe and effective. Developing training programs in Europe for hybrid neurosurgeons that can provide comprehensive patient care should be considered.

Analysis of complications and recurrences of aneurysm coiling with special emphasis on the stent-assisted technique

BACKGROUND AND PURPOSE

Stent-assisted coiling has expanded the treatment of intracranial aneurysms. With the use of continuously compiled data, we reviewed the role and drawbacks of stent-assisted coiling.

MATERIALS AND METHODS

We compiled data from consecutive patients from 2003-2012 who underwent coiling, with or without stent assistance. Clinical and angiographic results were analyzed retrospectively.

RESULTS

Of 1815 saccular aneurysms in 1505 patients, 323 (17.8%) were treated with stents (299 procedures) and 1492 (82.2%) without stents (1400 procedures). Procedure-related complications occurred in 9.4% with stents versus 5.6% without stents (P = .016, relative risk 1.5; 95% CI, 1.1-2.7). Ischemic complications were more frequent in the stent group than in the no-stent group (7.0% versus 3.5%; P = .005; relative risk, 1.7; 95% CI 1.2-2.5), as were hemorrhagic complications (2.3% versus 1.9%, P = .64). Procedure-induced mortality occurred in 2.7% (8/299) with stents versus 1.1% (15/1400) without stents (P = .029; relative risk, 2.0; 95% CI, 1.1-3.5). Logistic regression analysis identified wide-neck aneurysms as the most significant independent predictor of complications. A total of 64.1% (207/323) of aneurysms treated with stents and 70.3% (1049/1492) treated without stents have been followed, disclosing angiographic recurrence in 15.5% (32/207) versus 35.5% (372/1049), respectively (P < .0001). Logistic regression analysis showed that the presence of a stent was the most important factor for the reduction of angiographic recurrence (P < .0001; relative risk, 2.3; 95% CI, 1.6-3.3).

CONCLUSIONS

The stent-assisted coiling technique is associated with a significant decrease in recurrences but a significant increase in complications. The treatment of wide-neck aneurysms remains hazardous.

Dissociation of vasospasm-related morbidity and outcomes in patients with aneurysmal subarachnoid hemorrhage treated with clazosentan: a meta-analysis of randomized controlled trials

OBJECT

Clazosentan therapy after aneurysmal subarachnoid hemorrhage (SAH) has been found to be effective in reducing the incidence of vasospasm in randomized controlled trials. However, while vasospasm-related morbidity, including delayed ischemic neurological deficits (DINDs) and delayed cerebral infarctions, was consistently decreased, statistical significance was not demonstrated and outcomes were not affected by clazosentan treatment. The objective of this meta-analysis was to determine whether clazosentan treatment after aneurysmal SAH significantly reduced the incidence of DINDs and delayed cerebral infarctions and improved outcomes.

METHODS

All randomized controlled trials investigating the effect of clazosentan were retrieved via searches with sensitive and specific terms. Six variables were abstracted after the assessment of the methodological quality of the trials. Analyses were performed following the method guidelines of the Cochrane Back Review Group.

RESULTS

Four randomized, placebo-controlled trials met eligibility criteria, enrolling a total of 2181 patients. The meta-analysis demonstrated a significant decrease in the incidence of DINDs (relative risk [RR] 0.76 [95% CI 0.62-0.92]) and delayed cerebral infarction (RR 0.79 [95% CI 0.63-1.00]) in patients treated with clazosentan after aneurysmal SAH. However, this treatment regimen was not shown to outcomes including functional outcomes measured by Glasgow Outcome Scale-Extended (RR 1.12 [95% CI 0.96-1.30]) or mortality (RR 1.02 [95%CI 0.70-1.49]). Adverse events, including pulmonary complications, anemia, and hypotension, were all significantly increased in patients who received clazosentan therapy.

CONCLUSIONS

The results of the present meta-analysis show that treatment with clazosentan after aneurysmal SAH significantly reduced the incidence of the vasospasm-related DINDs and delayed cerebral infarctions, but did not improve poor neurological outcomes in patients with aneurysmal SAH. Further study is required to elucidate the dissociation between vasospasm-related morbidity and outcomes.

Rupture during the endovascular treatment of intracranial aneurysms: outcomes and technical aspects

OBJECT

The purpose of this study was to determine the incidence and outcomes of intraprocedural rupture (IPR) during endovascular coil embolization of intracranial aneurysm at a single center and to explore the technical reasons and put forward corresponding preventive measures for the feared event to serve as references for other endovascular specialists.

METHODS

The aneurysm database in our series was retrospectively reviewed. From April 2005 to March 2009, 176 aneurysms were consecutively treated with coils in 161 patients and IPR occurred in 12 patients. The medical records for the 12 patients were seriously examined.

RESULTS

Of the 12 patients (6.8 %), four were men and eight were women with a median age of 56 years. An emergency "rescue clipping" of the lesion was carried out in two patients, parent artery occlusion was performed in two cases, endovascular treatment was terminated in one case and aneurysm coiling was rapidly completed in the remaining seven cases. Complete occlusion was achieved in nine aneurysms and incomplete occlusion in one. One patient died, yielding a mortality rate of 8.3 %. The follow-up duration was 6-30 months (median 14 months) and the mean Glasgow Outcome Scale score at the last follow-up examination was 4.3.

CONCLUSIONS

The rate of IPR during endovascular coiling of intracranial aneurysms is quite low and the clinical outcome from this complication need not be catastrophic if managed appropriately. Improved operation skill and practical experience exchange among neuroradiologists are essential to lower the incidence or better patient prognoses.

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.

Mechanical thrombectomy in two patients using the Solitaire AB device in cerebral aneurysms during endovascular coil embolisation

Two men, 52 years and 54 years of age, presented with subarachnoid haemorrhage as a result of ruptured cerebral aneurysms. Both patients were treated with endovascular coil embolisation. Thromboembolic complications occurred in the middle cerebral artery during the procedure, and local thrombectomy was performed for recanalisation. Digital subtraction angiography revealed the immediate restoration of flow after mechanical thrombectomy with a stent in both patients. The Solitaire AB stent (ev3, Plymouth, MN, USA) can rapidly, safely, and effectively retrieve clots from the middle cerebral artery during endovascular embolisation.

A novel tissue engineering approach using an endothelial progenitor cell–seeded biopolymer to treat intracranial saccular aneurysms

Object

Recurrence after endovascular coiling of intracranial aneurysms is reported in up to 42% of cases and is attributed to the lack of endothelialization across the neck. In this study the authors used a novel tissue engineering approach to promote endothelialization by seeding endothelial progenitor cells (EPCs) within a fibrin polymer injected endovascularly into the aneurysm.

Methods

Experimental aneurysms were created in New Zealand White rabbits and were left untreated, surgically clipped, or embolized with platinum coils, fibrin biopolymer alone, or fibrin combined with autologous cultured EPCs.

Results

In aneurysms treated with EPCs, a confluent monolayer of endothelial cells with underlying neointima was demonstrated across the neck at 16 weeks posttreatment, which was not observed with aneurysms treated using the other methods.

Conclusions

This novel technique may address reasons for the limited durability of standard coil embolization and provides further avenues for the development of improved devices for the care of patients with aneurysms.

A 6-Fr guiding catheter (Slim Guide(®)) for use with multiple microdevices

BACKGROUND

We developed a new 6-Fr guiding catheter (Slim Guide(®)) that features a large lumen (0.072 inch) for performing advanced techniques as are required in patients with wide-necked aneurysms whose treatment with a single microcatheter is difficult.

METHODS

The Slim Guide was used to address 30 saccular and 20 dissecting aneurysms. All 50 patients presented with subarachnoid hemorrhage. To perform the advanced techniques we used SL-10(®) or Excel 14(®) and Hyperform(®) balloon microcatheters.

RESULTS

Of the 30 patients with saccular aneurysms, 20 were treated with the double microcatheter- and the other 10 with the balloon assist technique. All 20 patients with dissecting aneurysms were treated with the double microcatheter technique. We encountered slight interference during the treatment of one saccular aneurysm with the balloon assist technique using the Slim Guide guiding catheter; another patient with a saccular aneurysm treated with the balloon assist technique suffered a minor transient ischemic complication.

CONCLUSIONS

With the Slim Guide, the risks inherent in the application of advanced techniques may be decreased. Its use facilitates the coil embolization of aneurysms that pose treatment challenges.

Complications and adverse events associated with Neuroform stent-assisted coiling of wide-neck intracranial aneurysms

BACKGROUND

Successful experiences of the Neuroform stent-assisted coiling have been reported by many teams in endovascular neurosurgery centers throughout the world. However, most of the reported complications involved a limited number of patients.

OBJECTIVE

To systematically report the complications of Neuroform stent-assisted coiling of intracranial aneurysms and to tentatively assess the efficacy and safety of this method.

METHODS

A retrospective study of 232 consecutive patients with 239 wide-neck aneurysms treated with Neuroform stent-assisted coil embolization at our institution over a 6-year period was performed. Angiographic results and clinical outcome were evaluated. Cases with complications were analyzed.

RESULTS

Stenting was successful in 237 of 239 aneurysms. Favorable clinical outcome (modified Rankin score: 0-2) was observed in 88·3% of the patients. Procedure-related complications included thromboembolism (n = 13), intraprocedural rupture (n=8), coil protrusions (n=5), new mass effect (n=3), vessel injury (n=3), and stent dislodgement (n=2). Procedure-related morbidity and mortality were 4·2 and 1·3%, respectively. Non-procedural complications attributable to subarachnoid hemorrhage in 129 patients with ruptured aneurysms were symptomatic vasospasm (18·6%) and shunt-dependent hydrocephalus (6·9%). Angiography follow-up was obtained in 67·1% of the treated aneurysms. The overall recanalization rate was 14·5%. Delayed complications included in-stent stenosis (n=2) and penetrating artery occlusion (n=2) in follow-up period.

CONCLUSION

Neuroform sent-assisted coiling of intracranial aneurysm is a safe technique with relatively low recanalization rate. The main cause of morbidity and mortality is thromboembolism. Long-term effect on parent artery should be observed carefully.

Age-related complications following endovascular treatment of unruptured intracranial aneurysms

BACKGROUND AND PURPOSE

The factors that led us to do the research for this paper was a desire to see if elderly patients did as well as non-elderly patients during endovascular intracranial aneurysm treatment. By doing this research, we could better stratify the most appropriate treatment for each patient with an aneurysm. The purpose of this study was to determine whether the incidence of procedural complications was greater in the elderly, defined as patients older than 65 years of age, compared with nonelderly patients undergoing elective endovascular treatment for intracranial aneurysms.

MATERIALS AND METHODS

A retrospective review was performed in patients undergoing elective endovascular treatment of intracranial aneurysms between 2000 and 2010 at 1 institution. "Minor complications" were defined as those resulting in minimal or no loss of function that resolved before dismissal; "major complications" were complications that resulted in loss of function or complications that required a subsequent invasive therapy. Major complications were further stratified into those with and without neurologic disability, defined as an mRS score of >3. T tests and χ(2) analyses were used to compare groups.

RESULTS

Three hundred fifty-five patients underwent 394 endovascular procedures treating 75 aneurysm recurrences and 319 untreated aneurysms. One hundred eight (30%) were elderly. There was no significant difference in the rate of complications in the elderly compared with the nonelderly (33% versus 26%, respectively; P = .18). Major complications were significantly more prevalent in the elderly than in the nonelderly (17% versus 7.4%, respectively, P = .004). Major complications with neurologic disability were also significantly more prevalent in the elderly compared with the nonelderly (8.2% versus 1.8%, respectively, P = .004).

CONCLUSIONS

Major functional complications were markedly more common in the elderly compared with the nonelderly.

Cerecyte coil trial: procedural safety and clinical outcomes in patients with ruptured and unruptured intracranial aneurysms

BACKGROUND AND PURPOSE

This study arose from a need to systematically evaluate the clinical and angiographic outcomes of intracranial aneurysms treated with modified coils. We report the procedural safety and clinical outcomes in a prospective randomized controlled trial of endovascular coiling for ruptured and unruptured intracranial aneurysms, comparing polymer-loaded Cerecyte coils with bare platinum coils in 23 centers worldwide.

MATERIALS AND METHODS

Five hundred patients between 18 and 70 years of age with a ruptured or unruptured target aneurysm planning to undergo endovascular coiling were randomized to receive Cerecyte or bare platinum coils. Analysis was by intention to treat.

RESULTS

Two hundred forty-nine patients were allocated to Cerecyte coils and 251 to bare platinum coils. Baseline characteristics were balanced. For ruptured aneurysms, in-hospital mortality was 2/114 (1.8%) with Cerecyte versus 0/119 (0%) bare platinum coils. There were 8 (3.4%) adverse procedural events resulting in neurological deterioration: 5/114 (4.4%) with Cerecyte versus 3/119 (2.5%) with bare platinum coils (P = .22). The 6-month mRS score of ≤2 was not significantly different in 103/109 (94.5%) patients with Cerecyte and 110/112 (98.2%) patients with bare platinum coils. Poor outcome (mRS score of ≥3 or death) was 6/109 (5.5%) with Cerecyte versus 2/112 (1.8%) with bare platinum coils (P = .070). For UIAs, there was no in-hospital mortality. There were 7 (2.7%) adverse procedural events with neurological deterioration, 5/133 (3.8%) with Cerecyte versus 2/131 (1.5%) with bare platinum coils (P = .13). There was a 6-month mRS score of ≤2 in 114/119 (95.8%) patients with Cerecyte versus 123/123 (100%) patients with bare platinum coils. There was poor outcome (mRS ≥3 and 1 death) in 5/119 (4.2%) patients with Cerecyte versus 0/123 (0%) patients with bare platinum coils (P = .011).

CONCLUSIONS

There was a statistical excess of poor outcomes in the Cerecyte arm at discharge in the ruptured aneurysm group and at 6-month follow-up in the unruptured group. Overall adverse clinical outcomes and in-hospital mortality were exceptionally low in both groups.

Stent-supported aneurysm coiling: a literature survey of treatment and follow-up

BACKGROUND AND PURPOSE

Stent-supported aneurysm coiling has been utilized with increasing frequency over the past few years, particularly for addressing treatment of complex and wide-neck aneurysms. A sizable body of literature describing various experiences with stent-supported coiling now exists. The purpose of this research was to carry out a comprehensive literature survey of stent-supported aneurysm coiling.

MATERIALS AND METHODS

A survey of papers reporting results with stent-assisted aneurysm coiling through January 2011 was conducted to identify the prevalence of stent-related and other complications, occlusion rates, and clinical and angiographic follow-up data.

RESULTS

Thirty-nine articles with 1517 patients met inclusion criteria for initial analysis, follow-up analysis, or both. Overall, 9% of cases were confounded by a technical stent-related issue, including 4% failure of deployment. The overall procedure complication rate was 19%, with periprocedural mortality of 2.1%. Approximately 45% of aneurysms were completely occluded at first treatment session, increasing to 61% on follow-up. Approximately 3.5% in-stent stenosis and 0.6% stent occlusion were observed at angiographic follow-up. Delayed stroke or transient ischemic attack was reported in 3% of subjects. Within a subset of articles, the incidence of stent-related issues in the first 10 patients was significantly higher than in subsequent subjects, supporting the notion of a procedural "learning curve."

CONCLUSIONS

In experienced hands, the morbidity of stent-supported coiling is somewhat higher compared with "traditional" coiling. As might be expected, execution of the procedure appears improved with experience. Complete occlusion rates remain somewhat low. More and longer term angiographic follow-up information is needed to understand delayed stent-related issues and to better define the durability of treatment.

An analysis of inflation times during balloon-assisted aneurysm coil embolization and ischemic complications

BACKGROUND AND PURPOSE

The introduction of balloon remodeling has revolutionized the approach to coiling of wide-neck aneurysms. We studied the effects of balloon inflation during coil embolization on ischemic complications.

METHODS

A retrospective review was undertaken of the most recent 147 patients undergoing balloon remodeling for unruptured intracranial aneurysm coil embolization at a single institution (81 balloon, 66 unassisted). All underwent postprocedural MRI.

RESULTS

Among patients in the "balloon" group, the mean total inflation time was 18 minutes (range, 1-43), a mean number of inflations of 4 (range, 1-9), a mean maximum single inflation time of 7 minutes (range, 1-19), a mean reperfusion time of 2.2 minutes between inflations, and an average procedure time of 2 hours and 10 minutes. Asymptomatic diffusion-weighted imaging abnormalities were detected on postprocedural MRI in 21.5% of patients and symptomatic lesions were identified in 3.8%. Both silent and symptomatic ischemic rates were similar in the internal control group. Patients with ischemic findings were older and more likely have diabetes; no differences were found with respect to total balloon inflation time, number of inflations, maximum inflation time, or reperfusion times.

CONCLUSIONS

We found no significant relationship between balloon inflation practices and ischemic events. Older and diabetic patients were more likely to have ischemic events develop.

Stent-assisted coil embolization of wide-necked intracranial aneurysms using a semi-deployment technique: angiographic and clinical outcomes in 31 consecutive patients

We describe a modified stent-assisted coiling technique, named the semi-deployment technique, in the endovascular treatment of wide-neck aneurysms. Thirty-one consecutive patients with 31 wide-necked or fusiform intracranial aneurysms were treated with the semi-deployment technique. The technical feasibility of the procedure, procedure-related complications, angiographic results, clinical outcome and follow-up angiography were evaluated. In every case, the semi-deployment technique was successfully deployed. Immediate angiography demonstrated complete occlusion in 24 cases (77.4%), neck remnant in four cases (12.9%), and incomplete occlusion in three cases (9.7%). Procedural-related morbidity occurred in one patient (3.2%) but no procedural-related mortality. A favorable clinical outcome (Modified Ran-kin Scale score 0-2) was observed in 90.3% of the patients (average follow-up time, 23.1 months). No rehemorrhage of treated aneurysms occurred. Angiography follow-up was obtained in 22 cases (71.0 %). Three aneurysms (13.6 % of the follow-up angiograms) demonstrated recanalization. No delayed coil or stent migration was found. One patient had in-stent stenosis as a delayed complication. We found that the semi-deployment technique was helpful in the treatment of wide-neck aneurysms.

Is Clopidogrel Premedication Useful to Reduce Thromboembolic Events During Coil Embolization for Unruptured Intracranial Aneurysms?

BACKGROUND:

Thromboembolism is a common complication related to coil embolization of intracranial aneurysms.

OBJECTIVE:

To identify factors related to thromboembolic events during coil embolization for unruptured intracranial aneurysms and to evaluate the role of clopidogrel premedication to prevent thromboembolisms.

METHODS:

Since March 2006, clopidogrel has been administered to patients with unruptured aneurysms before coil embolization (the clopidogrel group) in our institution. The clopidogrel group (416 patients with 485 aneurysms) and the historical control group (140 patients with 159 aneurysms who received no antiplatelet premedication) were compared to find the efficacy of clopidogrel premedication. Various factors, including age, sex, body weight, and medical history of hypertension, diabetes mellitus, hyperlipidemia, smoking, previous stroke, and heart disease, as well as clopidogrel premedication, were analyzed in relationship to the development of a procedure-related thromboembolism.

RESULTS:

Procedure-related thromboembolic events tended to occur less frequently in the clopidogrel group compared with the control group (7.4% vs 12.6%; P = .05), and clopidogrel premedication could modify the risk in female patients from 11.1% to 5.2% (P = .04). The use of multiple logistic regression analysis identified clopidogrel premedication (P = .03), smoking (P = .002), and hyperlipidemia (P = .02) as significant factors related to the formation of thromboembolism.

CONCLUSION:

Clopidogrel premedication seems to have a beneficial effect in reducing the number of procedure-related thromboembolisms during coil embolization for unruptured intracranial aneurysms, especially in female patients. Smoking and hyperlipidemia were independent risk factors related to thromboembolism.

HyperForm balloon remodeling in the endovascular treatment of anterior cerebral, middle cerebral, and anterior communicating artery aneurysms: clinical and angiographic follow-up results in 800 consecutive patients

OBJECT

The purpose of this paper was to present the safety, efficacy, and clinical/angiographic follow-up results of HyperForm balloon-assisted endosaccular coil occlusion of distal anterior circulation bifurcation aneurysms.

METHODS

Over a 7-year period, the authors treated 864 middle cerebral artery, distal anterior cerebral artery bifurcation, and anterior communicating artery aneurysms by means of coil embolization with HyperForm balloon assistance in 800 patients. In 37 aneurysms, 2 HyperForm balloons were used simultaneously for remodeling.

RESULTS

The overall mortality rate was 7.1%, including 1.4% procedural mortality. Various neurological deficits were present at discharge in 8.9% of the patients, and 4.4% had permanent disabling morbidity 6 months posttreatment (modified Rankin Scale score ≥ 2). Thromboembolic complications developed during the treatment of 15 aneurysms (1.7%) causing morbidity or mortality in 10 cases (1.3%). There were 14 intraoperative perforations (1.6%). In all 14 cases, the HyperForm balloon saved patients from severe bleeding. The perforation led to morbidity or mortality in 3 cases (0.4%); there were no negative consequences in 11. There were 726 patients with 757 aneurysms (87.6%) available for follow-up. Control angiograms were obtained at 6 months in 386 patients, at 1 year in 267, and at 2 years in 104, revealing an 82% complete obliteration rate according to the most recent follow-up angiograms.

CONCLUSIONS

The satisfactory results obtained in this experience demonstrate that HyperForm balloon remodeling provides strong benefits for the endovascular management of middle cerebral, anterior cerebral, and anterior communicating artery aneurysms without increasing the risk of treatment. Not only does this technique allow for the safe treatment of these aneurysms, but it also expands the indications of endovascular treatment to include aneurysms that otherwise cannot be treated with simple coil embolization.

Acute serious rebleeding after angiographically successful coil embolization of ruptured cerebral aneurysms

PURPOSE

The present study investigated the incidence of acute rebleeding after successful coil embolization of a ruptured cerebral aneurysm, including clinical outcomes, and possible mechanisms of the events other than coil compaction and/or incomplete embolization.

MATERIALS AND METHODS

This study included 591 consecutive patients who presented with aneurysmal subarachnoid hemorrhage, were treated with coil embolization, and whose post-procedural angiography revealed successful embolization. Data were collected retrospectively from six patients who showed acute rebleeding despite that angiographically successful coil embolization was achieved. All clinical, radiological data and intraoperative videos were reviewed to identify causative factors which could have contributed to the occurrence of rebleeding.

RESULTS

Incidence of acute rebleeding after successful coil embolization of ruptured cerebral aneurysm was 1.0% (6/591). In all of these six patients, complete angiographic occlusion was achieved except in one case where a small residual neck was intentionally left to avoid compromise of the parent artery. Four of the six patients showed poor clinical courses, either died or recovered with severe disability. Whenever possible, we performed an immediate craniotomy for exploration and additional clipping. Based on intraoperative findings, we hypothesized that uneven distribution of the coil masses and spontaneous resolution of thrombus among the strands of coil (inter-coil-loop thrombolysis) could be possible mechanisms of rebleeding.

CONCLUSION

Acute rebleeding is extremely rare, but is possible as a complication of coil embolization of a ruptured cerebral aneurysm even when a case is angiographically successful. The higher degree of morbidity and mortality is a major concern. Therefore, further investigation to discover risk factors and causative mechanisms for such a complication is sorely needed.

Preinterventional clopidogrel response variability for coil embolization of intracranial aneurysms: clinical implications

BACKGROUND AND PURPOSE

Thromboembolism is one of the most serious complications in coil embolization for intracranial aneurysms, and antiplatelet premedication may reduce this complication. However, interindividual variation exists in the efficacy of CPG. This study sought to elucidate the clinical implications of preinterventional CPG response variability in patients who undergo coil embolization for intracranial aneurysms.

MATERIALS AND METHODS

CPG premedication was given to 186 consecutive patients with 209 aneurysms who underwent elective coil embolization, and the response to the premedication was measured by a point-of-care antiplatelet function test (VerifyNow assay). Patients were stratified into 4 quartiles according the test results, and their correlation with the occurrence of periprocedural complications was analyzed. The contribution of a variety of variables to the high PRU was also tested.

RESULTS

In this cohort, rates of thromboembolic events and all adverse events were 7.5% and 9.1%, respectively. The quartiles of the P2Y12 reaction unit of the ADP channel (PRU) showed a significant tendency toward thromboembolic events (P = .013) and all procedure-related adverse events (P = .009), while those of the BASE and percentage inhibition did not. Thromboembolic events occurred in 17.0% and procedure-related adverse events, in 21.3% of the patients in the fourth quartile. Female sex was the only significant factor related to the fourth quartile of PRU in the multiple logistic regression analysis (P = .014).

CONCLUSIONS

Procedure-related thromboembolic events occurred more frequently in patients in the upper quartile with higher PRU, especially in the fourth quartile. Further study including a large number of patients is expected to confirm this finding.

Y-stent-assisted coil embolization for the management of unruptured cerebral aneurysms: report of six cases

BACKGROUND

The advent of stent-assisted coil embolization has revolutionized the endovascular management of complex intracranial aneurysms. Although performed routinely in most cerebrovascular centers, there are not many case series reported about the Y-stent technique for coil placement in cerebral aneurysms. The authors present the second largest series available within the neurosurgical literature.

METHODS

The authors have retrospectively reviewed the medical records and angiographic data of six patients who were diagnosed as having unruptured cerebral aneurysms and subsequently treated using "Y" stent-assisted coil embolization. Five out of six cerebral aneurysms in this study were located at the basilar tip while the remaining one was at the left MCA trifurcation. Aneurysms ranged in size from 8-22 mm. All patients were female with ages ranging from 37-70 years. One patient presented with recurrence of an aneurysm previously managed with a balloon-assisted coil embolization. Another patient presented after a failed trial of a balloon-assisted procedure. One patient had originally been diagnosed with multiple aneurysms of varying size and location.

RESULTS

A "Y" configuration was successfully established in all six patients. Five patients have had a symptom-free recovery period at average follow-up period of 36.7 months. The remaining patient is notable for recurrence that was discovered on angiogram 32 months postoperatively.

CONCLUSIONS

The proposed Y-stent technique is a safe and effective option that can be employed in the endovascular reconstruction of unruptured intracranial aneurysms of complex location and orientation. These methods serve as an acceptable alternative in the management of aneurysms traditionally managed with microsurgery. Hemodynamic assessment has shown Y-stenting to be an advantageous therapy option, yet further studies are required to assess these parameters in alternative therapies.

Defining the risk of retreatment for aneurysm recurrence or residual after initial treatment by endovascular coiling: a multicenter study

OBJECTIVE

Endovascular treatment of intracranial aneurysms is less invasive than surgical repair but poses a higher risk for aneurysm recurrence, which may necessitate retreatment, thus adding to the long-term risk. Cerebrovascular neurosurgeons from 8 institutions in the United States and Puerto Rico collaborated to assess the risk of retreatment for residual or recurrent aneurysms after the initial endovascular coiling.

METHODS

Data were prospectively recorded for 311 patients with coiled intracranial aneurysms who underwent 352 retreatment procedures after angiographic or clinical recurrence (hemorrhage after initial coiling). Results analyzed included procedural complications and procedure-related morbidity. Morbidity was classified as major (modified Rankin scale score > 3) or minor, and temporary (<30 days) or permanent (>30 days).

RESULTS

Retreatment mortality was 0.85% per procedure and 0.96% per patient. Treatment-related rates were 0.32% per patient (0.28% per procedure) for permanent or temporary major disability; 1.29% for permanent minor disability (1.14% per procedure); and 1.61% for temporary minor disability (1.42% per procedure). Total risk for death or permanent major disability was 1.28% per patient and 1.13% per procedure.

CONCLUSION

Retreatment poses a low risk for patients with recurrences of intracranial aneurysms after initial coiling; this risk is smaller than that posed by the initial endovascular therapy. The risk of disability associated with retreatment for aneurysm recurrence after coiling must be considered prospectively in the choice of treatment but with the recognition that its effects are low in the overall management risk.

Endovascular treatment of middle cerebral artery aneurysms with detachable coils: angiographic and clinical outcomes in 115 consecutive patients

OBJECTIVE

Because of their anatomic configuration, middle cerebral artery (MCA) aneurysms are most often treated with surgical clipping. However, endovascular coil embolization of these aneurysms is an increasingly used alternative. We retrospectively reviewed the anatomic and clinical outcomes of patients with MCA aneurysms who underwent endovascular treatment at our institution.

METHODS

One hundred fifteen MCA aneurysms in 115 patients (mean age, 55.1 years) were treated by an endovascular technique from April 1990 to March 2007. Forty-eight patients (42%) presented with acute subarachnoid hemorrhage, and 67 patients (58%) had unruptured aneurysms. Fifty-three aneurysms (46%) were small with a small neck, 28 (24%) were small with a wide neck, 22 (19%) were large, and 12 (11%) were giant.

RESULTS

Angiographic results immediately after embolization showed complete occlusion in 53 aneurysms (46%), a neck remnant in 51 (44%), and incomplete occlusion in 3 (3%). Because of anatomic difficulties, we could not embolize 8 aneurysms (7%). Thirteen patients underwent combined treatment that included endovascular and extracranial-intracranial bypass surgery. Morbidity and mortality rates were 6.9% (8 patients) and 3% (3 patients), respectively. Procedure-related complications were encountered in 10 patients (9%). Seventy patients had long-term follow- up angiograms. Seven aneurysms (10%) were recanalized; all were large or giant. One partially embolized large aneurysm ruptured 13 months after embolization.

CONCLUSION

In this series, endovascular coil embolization of MCA aneurysms has morbidity and mortality rates comparable to those of conventional surgical clipping. Combined treatment of endovascular and bypass surgery can successfully treat large or giant complex fusiform MCA aneurysms.

Intra-arterial tirofiban infusion for thromboembolism during endovascular treatment of intracranial aneurysms

OBJECTIVE

Thromboembolism is one of the most common and serious complications associated with the endovascular embolization of intracranial aneurysms. We report our clinical experiences with intra-arterial tirofiban infusion during aneurysm embolization.

METHODS

The clinical, radiological, and laboratory data of 24 patients harboring 25 aneurysms (25 procedures) who underwent intra-arterial tirofiban infusion for thromboembolism during the endovascular treatment of intracranial aneurysms were reviewed retrospectively. Thrombi or emboli were resolved by superselective intra-arterial tirofiban infusion via a microcatheter.

RESULTS

The study cohort comprised 14 unruptured and 11 ruptured aneurysms. Intra-arterially infused tirofiban doses ranged from 0.2 to 1.0 mg (mean +/- standard deviation, 0.64 +/- 0.25 mg). Thromboemboli were resolved, and arteries were recanalized on all occasions except one: a case of distal middle cerebral artery embolism. No hemorrhagic complications related to intra-arterial tirofiban infusion occurred.

CONCLUSION

Intra-arterial tirofiban delivery appears to be a safe and effective treatment modality when thromboembolism is encountered during the endovascular treatment of intracranial aneurysms.

Intracranial aneurysm perforation during endosaccular coiling: impact on clinical outcome, initial occlusion, and recanalization rates

OBJECTIVE

The aim of this study was to evaluate the acute and follow-up outcomes of cerebral aneurysms that perforated during endovascular treatment.

METHODS

Nine hundred ten patients harboring 1056 intracranial aneurysms received 1164 endovascular treatments over 11 years at our institution. Intraprocedural aneurysm perforation occurred in 20 cases (1.7%). Thirteen cases (mean size, 6.2 mm) demonstrated contrast leakage, whereas the other 7 cases (mean size, 5.3 mm) showed only nonleak coil extrusion from the aneurysms. Results of follow-up magnetic resonance angiography or catheter angiography at least 6 months after embolization were available in 11 contrast leak and 6 nonleak cases. Acute and follow-up results were reviewed.

RESULTS

New neurological deficits directly associated with aneurysm perforation were identified at discharge in only 4 contrast leak patients (20%). Their respective modified Rankin Scale scores were 1, 2, 3, and 5. Respective acute results in the contrast leak and nonleak groups were as follows: complete occlusion in 7 (54%) and 3 (43%), neck remnant in 3 (23%) and 4 (57%), and incomplete occlusion in 3 (23%) and 0. Respective follow-up results were as follows: major recanalization in 3 (27%) and 1 (17%), minor recanalization in 3 (27%) and 1 (17%), and stable occlusion in 5 (46%) and 4 (67%).

CONCLUSION

Intraprocedural aneurysm perforation with leakage of contrast appears to be associated with relatively high rates of incomplete acute results and major recanalizations during follow-up, although perforation frequently occurs in small aneurysms. Nonleak perforation may also lead to major recanalization through the potentially weak point of initial coil extrusion.

Risk of hemorrhage in combined neuroform stenting and coil embolization of acutely ruptured intracranial aneurysms

SUMMARY

Stenting as adjuvant therapy for the coiling of acutely ruptured aneurysms remains controversial due to the necessity of anticoagulation and antiplatelet medications. We report our experience using the Neuroform stent in the management of 41 aneurysms in 40 patients over a period of three years. For aneurysms whose open surgical risk remains excessive with a morphology that would preclude complete embolization, the risks of stenting may be warranted.

Endovascular coiling of cerebral aneurysms using "bioactive" or coated-coil technologies: a systematic review of the literature

SUMMARY

Second-generation coils have been available since 2002. We wanted to assess their performance and appraise available evidence. Therefore we performed a systematic review of the literature from 2002 to 2007. There were 27 studies with a total of 2390 patients that met pre-specified inclusion criteria. All studies were classed as having a high risk of bias. There were no randomized trials and for most studies results were not independently assessed and follow-up periods were short (mean 7 months). There were large differences in demographic and aneurysm characteristics, making comparisons between coil cohorts difficult. Procedure-related morbidity and mortality were similar for all coil types. Hemorrhagic events during follow-up were few, in the range of 1%/year for all coil types. The available literature is of poor quality and clinical series provide very little evidence in favor of second-generation coils. Positive randomized trial results are needed to justify routine clinical use. This systematic review illustrates the failure of the industry, the regulatory authorities, and the neurointerventional community combined to provide a reliable and prudent approach to the introduction of new devices.