Stereotactic radiosurgery is an effective management strategy for properly selected patients with arteriovenous malformations (AVMs). However, the risk of postradiosurgical radiation-related injury is higher in patients with large AVMs. Multistaged volumetric management of large AVMs was undertaken to limit the radiation exposure to the surrounding normal brain. This strategy offers a promising method for obtaining high AVM obliteration rates with minimal normal tissue damage. The use of embolization as an adjunctive method in the treatment of large AVMs remains controversial. Unfortunately, staged-volume radiosurgery (SVR) has a number of potential pitfalls that affect the outcome. The aim of this article is to highlight the role of SVR in the treatment of large AVMs, to discuss the outcome comparing it to other treatment modalities, and to discuss the potential improvement that could be introduced to this method of treatment.
Kenan AlKhalili, Nohra Chalouhi, Stavropoula Tjoumakaris, Robert Rosenwasser, and Pascal Jabbour
L. Fernando Gonzalez, Nohra Chalouhi, Stavropoula Tjoumakaris, Pascal Jabbour, Aaron S. Dumont, and Robert H. Rosenwasser
Multiple approaches have been used to treat carotid-cavernous fistulas (CCFs). The transvenous approach has become a popular and effective route. Onyx is a valuable tool in today's endovascular armamentarium. The authors describe the use of a balloon-assisted technique in the treatment of CCFs with Onyx and assess its feasibility, utility, and safety.
The authors searched their prospectively maintained database for CCFs embolized using Onyx with the assistance of a compliant balloon placed in the internal carotid artery (ICA).
Five patients were treated between July 2009 and July 2011 at the authors' institution. A balloon helped to identify the fistulous point, served as a buttress for coils, protected from inadvertent arterial embolizations, and prevented Onyx and coils from obscuring the ICA during the course of embolization. No balloon-related complications were noted in any of the 5 cases. All 5 fistulas were completely obliterated at the end of the procedure. Four patients had available clinical follow-ups, and all 4 showed reversal of nerve palsies.
Balloon-assisted Onyx embolization of CCFs offers a powerful combination that prevents inadvertent migration of the embolic material into the arterial system, facilitates visualization of the ICA, and serves as a buttress for coils deployed in the cavernous sinus through the fistulous point. Despite adding another layer of technical complexity, an intraarterial balloon can provide valuable assistance in the treatment of CCFs.
Badih Daou, Christine Hammer, Nohra Chalouhi, Robert M. Starke, Pascal Jabbour, Robert H. Rosenwasser, and Stavropoula Tjoumakaris
Dissection of the carotid and vertebral arteries can result in the development of aneurysmal dilations. These dissecting pseudoaneurysms can enlarge and cause symptoms. The objective of this study is to provide insight into the progression of dissecting pseudoaneurysms and the treatments required to manage them.
A review of the electronic medical records was conducted to detect patients with carotid and vertebral artery dissection. An imaging review was conducted to identify patients with dissecting pseudoaneurysms. One hundred twelve patients with 120 dissecting pseudoaneurysms were identified. Univariate and multivariate analyses were conducted to assess the factors associated with undergoing further interventions other than medical treatment, pseudoaneurysm enlargement, pseudoaneurysms resulting in ischemic and nonischemic symptoms, and clinical outcome.
Overall, 18.3% of pseudoaneurysms were intracranial and 81.7% were extracranial, and the average size was 7.3 mm. The mean follow-up time was 29.3 months; 3.3% of patients had a recurrent transient ischemic attack, no patients had a recurrent stroke, and 14.2% of patients had recurrence of nonischemic symptoms (headache, neck pain, Horner syndrome, or cranial nerve palsy). Follow-up imaging demonstrated that 13.8% of pseudoaneurysms had enlarged, 30.2% had healed, and 56% had remained stable. In total, 20.8% of patients had an intervention other than medical treatment. Interventions included stenting, coiling, flow diversion, and clipping. Predictors of intervention included increasing size, size > 10 mm, location in the C2 (petrous) segment of the internal carotid artery (ICA), younger age, hyperlipidemia, pseudoaneurysm enlargement, and any symptom development. Significant predictors of enlargement included smoking, history of trauma, C2 location, hyperlipidemia, and larger initial pseudoaneurysm size. Predictors of pseudoaneurysm resulting in recurrent ischemic and nonischemic symptoms included increasing size and location in the petrous segment of the ICA. Smoking was a predictor of unfavorable outcome.
Dissecting pseudoaneurysms have a benign course and most will not cause symptoms or enlarge on follow-up. Medical treatment can be a sufficient, initial treatment for dissecting pseudoaneurysms.
Badih Daou, Elias Atallah, Nohra Chalouhi, Robert M. Starke, Jeffrey Oliver, Maria Montano, Pascal Jabbour, Robert H. Rosenwasser, and Stavropoula I. Tjoumakaris
The Pipeline embolization device (PED) has become a valuable tool in the treatment of cerebral aneurysms. Although failures with PED treatment have been reported, the characteristics and course of these aneurysms remain a topic of uncertainty.
Electronic medical records and imaging studies were reviewed for all patients treated with the PED between July 2010 and March 2015 to identify characteristics of patients and aneurysms with residual filling after PED treatment.
Of 316 cases treated at a single institution, 281 patients had a long-term follow-up. A total of 52 (16.4%) aneurysms with residual filling were identified and constituted the study population. The mean patient age in this population was 58.8 years. The mean aneurysm size was 10.1 mm ± 7.15 mm. Twelve aneurysms were fusiform (23%). Of the aneurysms with residual filling, there were 20 carotid ophthalmic (CO) aneurysms (20% of all CO aneurysms treated), 10 other paraclinoid aneurysms (16.4% of all paraclinoid aneurysms), 7 posterior communicating artery (PCoA) aneurysms (21.9% of all PCoA aneurysms), 7 cavernous internal carotid artery (ICA) aneurysms (14.9% of all cavernous ICA aneurysms), 4 vertebrobasilar (VB) junction aneurysms (14.8% of all VB junction aneurysms), and 3 middle cerebral artery (MCA) aneurysms (25% of all MCA aneurysms). Eleven patients underwent placement of more than one PED (21.2%), with a mean number of devices of 1.28 per case. Eight of 12 aneurysms were previously treated with a stent (15.4%). Nineteen patients underwent re-treatment (36.5%); the 33 patients who did not undergo re-treatment (63.5%) were monitored by angiography or noninvasive imaging. In multivariate analysis, age older than 65 years (OR 2.65, 95% CI 1.33–5.28; p = 0.05), prior stent placement across the target aneurysm (OR 2.94, 95% CI 1.15–7.51; p = 0.02), aneurysm location in the distal anterior circulation (MCA, PCoA, and anterior choroidal artery: OR 2.72, 95% CI 1.19–6.18; p = 0.017), and longer follow-up duration (OR 1.06, 95% CI 1.03–1.09; p < 0.001) were associated with incomplete aneurysm occlusion.
While the PED can allow for treatment of large, broad-necked aneurysms with high efficacy, treatment failures do occur (16.4%). Aneurysm size, shape, and previous treatment may influence treatment outcome.
Nohra Chalouhi, Aaron S. Dumont, Ciro Randazzo, Stavropoula Tjoumakaris, L. Fernando Gonzalez, Robert Rosenwasser, and Pascal Jabbour
With the widespread use of brain imaging studies, neurosurgeons have seen a marked increase in the number of incidental intracranial lesions, including vascular abnormalities. Specifically, the detection of incidentally discovered aneurysms, arteriovenous malformations, cavernous angiomas, developmental venous anomalies, and capillary telangiectasias has increased. The best management strategy for most of these lesions is controversial. Treatment options include observation, open surgery, endovascular procedures, and radiosurgery. Multiple factors should be taken into account when discussing treatment indications, including the natural history of the disease and the risk of the treatment. In this article, the authors focus on the natural history of these lesions and the risk of the treatment, and they give recommendations regarding the most appropriate management strategy based on the current evidence in the literature and their experience with intracranial vascular abnormalities.
Nohra Chalouhi, Rohan Chitale, Pascal Jabbour, Stavropoula Tjoumakaris, Aaron S. Dumont, Robert Rosenwasser, and L. Fernando Gonzalez
Given that relatives of patients with intracranial aneurysms (IAs) or subarachnoid hemorrhage have a greater risk of harboring an aneurysm, family screening has become a common practice in neurosurgery. Unclear data exist regarding who should be screened and at what age and interval screening should occur. Multiple factors including the natural history of IAs, the risk of treatment, the cost of screening, and the psychosocial impact of finding an aneurysm should be taken into account when family screening is considered. In this paper, the authors review the current literature regarding risk factors and natural history of sporadic and familial aneurysms. Based on these data the authors assess current recommendations for screening and propose their own recommendations.
Badih Daou, Nohra Chalouhi, Robert M. Starke, Guilherme Barros, Lina Ya'qoub, John Do, Stavropoula Tjoumakaris, Robert H. Rosenwasser, and Pascal Jabbour
With the increasing number of aneurysms treated with endovascular coiling, more recurrences are being encountered. The aim of this study was to evaluate the efficacy and safety of microsurgical clipping in the treatment of recurrent, previously coiled cerebral aneurysms and to identify risk factors that can affect the outcomes of this procedure.
One hundred eleven patients with recurrent aneurysms whose lesions were managed by surgical clipping between January 2002 and October 2014 were identified. The rates of aneurysm occlusion, retreatment, complications, and good clinical outcome were retrospectively determined. Univariate and multivariate logistic regressions were performed to identify factors associated with these outcomes.
The mean patient age was 50.5 years, the mean aneurysm size was 7 mm, and 97.3% of aneurysms were located in the anterior circulation. The mean follow-up was 22 months. Complete aneurysm occlusion, as assessed by intraoperative angiography, was achieved in 97.3% of aneurysms (108 of 111 patients). Among patients, 1.8% (2 of 111 patients) had a recurrence after clipping. Retreatment was required in 4.5% of patients (5 of 111) after clipping. Major complications were observed in 8% of patients and mortality in 2.7%. Ninety percent of patients had a good clinical outcome. Aneurysm size (OR 1.4, 95% CI 1.08–1.7; p = 0.009) and location in the posterior circulation were significantly associated with higher complications. All 3 patients who had coil extraction experienced a postoperative stroke. Aneurysm size (OR 1.2, 95% CI 1.02–1.45; p = 0.025) and higher number of interventions prior to clipping (OR 5.3, 95% CI 1.3–21.4; p = 0.019) were significant predictors of poor outcome. An aneurysm size > 7 mm was a significant predictor of incomplete obliteration and retreatment (p = 0.018).
Surgical clipping is safe and effective in treating recurrent, previously coiled cerebral aneurysms. Aneurysm size, location, and number of previous coiling procedures are important factors to consider in the management of these aneurysms.
Elias Atallah, Hassan Saad, Kimon Bekelis, Nohra Chalouhi, Stavropoula Tjoumakaris, David Hasan, Jorge Eller, David Stidd, Robert H. Rosenwasser, and Pascal Jabbour
Thromboembolic complications continue to be encountered with Pipeline embolization devices (PEDs) despite routine clopidogrel/aspirin antiplatelet therapy. This study examined the safety and efficacy of prasugrel in the management of clopidogrel-resistant patients treated for cerebral aneurysms.
Four hundred thirty-seven consecutive patients were identified between January 2011 and May 2016. Patients allergic, or having less than 30% platelet inhibition, to a daily 75-mg dose of clopidogrel received 10 mg of prasugrel daily (n = 20) or 90 mg of ticagrelor twice daily (n = 2). The mean (± SD) follow-up duration was 15.8 ± 12.4 months. The primary outcome was the modified Rankin Scale (mRS) score registered before discharge and at each follow-up visit. To control confounding, multivariable mixed-effects logistic regression and propensity score conditioning were used.
Twenty-six (5.9%) of 437 patients presented with a subarachnoid hemorrhage (SAH). The mean patient age was 56.3 years, and 62 were women (14.2%). One of the 7 patients lost to follow-up received prasugrel. One patient was allergic to clopidogrel and prasugrel simultaneously. All patients receiving prasugrel or ticagrelor (n = 22) had an mRS score ≤ 2 on their latest follow-up visit (mean score 0.67 ± 1.15). In a multivariate analysis, clopidogrel did not affect the mRS score on last follow-up (p = 0.14). Multivariable logistic regression showed that clopidogrel was not associated with an increased long-term recurrence rate (OR 0.17, 95% CI 0.01–2.70, p = 0.21), an increased thromboembolic complication rate (OR 0.46, 95% CI 0.12–1.67, p = 0.24), or an increased hemorrhagic event rate (OR 0.39, 95% CI 0.91–1.64, p = 0.20). None of the patients receiving prasugrel or ticagrelor died or suffered a long-term recurrence or a hemorrhagic event; only 1 patient suffered from mild aphasia subsequent to a thromboembolic event. Three patients taking clopidogrel died during the study: 2 from acute SAH and 1 from intraparenchymal hemorrhage. Clopidogrel was not associated with an increased mortality rate (OR 2.18, 95% CI 0.11–43.27, p = 0.61). The same associations were present in propensity score–adjusted models.
In a cohort of patients treated with PEDs, prasugrel (10 mg/day) was a safe alternative to clopidogrel-resistant or clopidogrel-allergic patients, or nonresponders.
James D. Rossen, Nohra Chalouhi, Shafik N. Wassef, Jacob Thomas, Taylor J. Abel, Pascal M. Jabbour, David K. Kung, and David M. Hasan
The optimal antiplatelet medication protocol for prevention of thrombotic complications after stent-assisted coil embolization of cerebral aneurysms is unclear. Early cessation of antiplatelet agents may be associated with an increased risk of cerebral ischemic events. In this study, the authors assess the incidence of stroke or transient ischemic attack (TIA) following discontinuation of a 6-week course of clopidogrel in patients with cerebral aneurysms treated with stent-assisted techniques.
A retrospective review was conducted in all patients with cerebral aneurysms undergoing stent-assisted coil embolization or stent-in-stent flow diversion at the University of Iowa during a 24-month period. The antiplatelet protocol was 81 mg aspirin and 75 mg clopidogrel daily for 6 weeks, followed by 325 mg aspirin daily indefinitely. The incidence of stroke or TIA was determined by a retrospective review of medical records generated during a 3-month period following discontinuation of clopidogrel.
A total of 154 patients underwent aneurysm treatment with stent techniques during this interval. Documentation of neurological follow-up 3 months after discontinuation of a 6-week clopidogrel treatment was available in 121 (78.6%) of 154 patients. Of these 121 patients, 114 were treated with stent-assisted coil embolization and 7 with stent-in-stent flow diversion. Six patients (5%) suffered an ischemic event after cessation of clopidogrel, with 2 events occurring within the first 2 weeks. Specifically, the rate of ischemic events was 5 (4.3%) of 114 in the “stent-coil” treatment group and 1 (14.3%) of 7 in the stent-in-stent group. Treatment had been performed in the setting of a subarachnoid hemorrhage in 1 patient. Atypical aneurysm features and technical factors predisposing to thrombotic events were found in all but one of these patients. Similarly, cardiovascular risk factors were present in 5 of the 6 patients in whom ischemic events developed after clopidogrel discontinuation.
Clopidogrel discontinuation is associated with a 5% risk of ischemic events in patients treated with stent techniques. Any stroke related to clopidogrel discontinuation is avoidable, and longer treatment is therefore clearly necessary. Patients with cardiovascular risk factors, high-risk aneurysm features, and those undergoing stent-in-stent flow diversion might benefit the most from longer clopidogrel therapy.
Badih Daou, Edison P. Valle-Giler, Nohra Chalouhi, Robert M. Starke, Stavropoula Tjoumakaris, David Hasan, Robert H. Rosenwasser, Ryan Hebert, and Pascal Jabbour
The Pipeline Embolization Device (PED) has become an effective treatment strategy for some cerebral aneurysms. Concerns regarding the patency of branch arteries have been raised. The objective of this study was to assess the patency of the posterior communicating artery (PCoA) following treatment of PCoA aneurysms using the PED.
All patients with PCoA aneurysms treated with the PED who had angiographic follow-up were retrospectively identified. The patency of the PCoA at follow-up was evaluated by 2 authors who were not involved in the intervention. Univariate and multivariate analyses were performed to identify factors associated with the following: 1) PCoA patency versus no or diminished flow, and 2) PCoA patency and diminished flow versus PCoA occlusion.
Thirty patients with an angiographic follow-up of 6 months were included. Aneurysm obliteration was achieved in 25 patients (83.3%). The PCoA was patent in 7 patients (23.3%), had diminished flow in 7 patients (23.3%), and was occluded in 16 patients (53.3%). In the univariate analysis of outcome, there was a trend for aneurysms with incomplete occlusion, aneurysms not previously treated, those with presence of a fetal PCoA, and those with an artery coming from the aneurysm to have higher odds of the PCoA remaining patent. In univariate and multivariate analyses of factors associated with outcome, fetal PCoA and presence of an artery coming from the aneurysm were associated with the PCoA remaining open with or without diminished flow. No patients had symptoms related to PCoA occlusion.
Occlusion and diminished flow through the PCoA is common following PED treatment of PCoA aneurysms. However, it is clinically insignificant in most cases.