Michelle H. Chua

Pipeline Embolization Device for small paraophthalmic artery aneurysms with an emphasis on the anatomical relationship of ophthalmic artery origin and aneurysm

OBJECTIVE Contemporary treatment for paraophthalmic artery aneurysms includes flow diversion utilizing the Pipeline Embolization Device (PED). Little is known, however, about the potential implications of the anatomical relationship of the ophthalmic artery (OA) origin and aneurysm, especially in smaller aneurysms. METHODS Four major academic institutions in the United States provided data on small paraophthalmic aneurysms (≤ 7 mm) that were treated with PED between 2009 and 2015. The anatomical relationship of OA origin and aneurysm, radiographic outcomes of aneurysm occlusion, and patency of the OA were assessed using digital subtraction angiography. OA origin was classified as follows: Type 1, OA separate from the aneurysm; Type 2, OA from the aneurysm neck; and Type 3, OA from the aneurysm dome. Clinical outcome was assessed using the modified Rankin Scale, and visual deficits were categorized as transient or permanent. RESULTS The cumulative number of small paraophthalmic aneurysms treated with PED between 2009 and 2015 at the 4 participating institutions was 69 in 52 patients (54.1 ± 13.7 years of age) with a male-to-female ratio of 1:12. The distribution of OA origin was 72.5% for Type 1, 17.4% for Type 2, and 10.1% for Type 3. Radiographic outcome at the last follow-up (median 11.5 months) was available for 54 aneurysms (78.3%) with complete, near-complete, and incomplete occlusion rates of 81.5%, 5.6%, and 12.9%, respectively. Two aneurysms (3%) resulted in transient visual deficits, and no patient experienced a permanent visual deficit. At the last follow-up, the OA was patent in 96.8% of treated aneurysms. Type 3 OA origin was associated with a lower rate of complete aneurysm occlusion (p = 0.0297), demonstrating a trend toward visual deficits (p = 0.0797) and a lower rate of OA patency (p = 0.0783). CONCLUSIONS Pipeline embolization treatment of small paraophthalmic aneurysms is safe and effective. An aneurysm where the OA arises from the aneurysm dome may be associated with lower rates of aneurysm occlusion, OA patency, and higher rates of transient visual deficits.

Validation of a System to Predict Recanalization After Endovascular Treatment of Intracranial Aneurysms.

BACKGROUND With increasing use of endovascular techniques in the treatment of ruptured and unruptured aneurysms, the issue of obliteration efficacy has become increasingly important. We have previously reported the Aneurysm Recanalization Stratification Scale, which uses accessible predictors including aneurysm-specific factors (size, rupture, and intraluminal thrombosis) and treatment-related features (treatment modality and immediate angiographic result) to predict retreatment risk after endovascular therapy. OBJECTIVE To assess the external validity of the Aneurysm Recanalization Stratification Scale. METHODS External validity was assessed in independent cohorts from 4 centers in the United States and Canada where endovascular and open neurovascular procedures are performed, and in a multicenter cohort of 1543 patients. Probability of retreatment stratified by risk score was derived for each center and the combined multicenter cohort. RESULTS Despite moderate variability in retreatment rate among centers (29.5%, 9.9%, 9.6%, 26.3%, 19.7%, and 18.3%), the Aneurysm Recanalization Stratification Scale demonstrated good predictive value with C-statistics of 0.799, 0.943, 0.780, 0.695, 0.755, and 0.719 for each center and the combined cohort, respectively. Probability of retreatment stratified by risk score for the combined cohort is as follows: -2, 4.9%; -1, 5.7%; 0, 5.8%; 1, 13.1%; 2, 19.2%; 3, 34.9%; 4, 32.7%; 5, 73.2%; 6, 89.5%; and 7, 100.0%. CONCLUSION Surgical decision-making and patient-centered informed consent require comprehensive and accessible information on treatment efficacy. The Aneurysm Recanalization Stratification Scale is a valid prognostic index. This is the first comprehensive model that has been developed to quantitatively predict retreatment risk following endovascular therapy.

Antifibrinolytic therapy in aneurysmal subarachnoid hemorrhage increases the risk for deep venous thrombosis: A case–control study

OBJECTIVES Aneurysm re-rupture is associated with significant morbidity and mortality in aneurysmal subarachnoid hemorrhage (aSAH). While antifibrinolytics reduce aneurysm re-rupture rates, they have been associated with hydrocephalus, delayed cerebral ischemia, and venous thrombosis. We performed a case-control study in patients enrolled in the Cerebral Aneurysm Renin Angiotensin System (CARAS) study to evaluate the impact of short course (<48 h) ɛ-aminocaproic acid (EACA) on deep venous thrombosis (DVT) rates. PATIENTS AND METHODS A case-control study design was utilized to evaluate the effect of EACA on DVT formation. All cases and controls were obtained from the CARAS study, a prospective, blinded study assessing the association of polymorphisms in the renin angiotensin system and aSAH. RESULTS One hundred and twenty-eight eligible patients were enrolled in CARAS. Overall, 48 (37.5%) patients were screened for DVT, 57 (44.5%) patients were treated with short course (<48 h) EACA, and 8 (6.3%) patients suffered a re-rupture (4 treated with EACA). Ten patients (7.8%) were diagnosed with DVT as evidenced by Doppler US and represent the cases. Twenty controls without evidence of a DVT matched for age, sex, race, tobacco history, Hunt-Hess score, Fisher grade, body mass index, and length of stay were identified from the remaining pool of 118 patients. EACA was found to significantly increase the risk of DVT formation in patients with aSAH (OR 8.49, CI 1.27-77.1). CONCLUSION Short course (<48 h) administration of EACA in patients with aneurysmal subarachnoid hemorrhage is associated with an 8.5 times greater risk of DVT formation.

Stratification of recanalization for patients with endovascular treatment of intracranial aneurysms.

BACKGROUND With the increasing use of endovascular techniques in the treatment of both ruptured and unruptured intracranial aneurysms, the issue of obliteration efficacy has become increasingly important. OBJECTIVE To systematically develop a comprehensive model for predicting retreatment with various types of endovascular treatment. METHODS We retrospectively reviewed medical records that were prospectively collected for 305 patients who received endovascular treatment for intracranial aneurysms from 2007 to 2013. Multivariable logistic regression was performed on candidate predictors identified by univariable screening analysis to detect independent predictors of retreatment. A composite risk score was constructed based on the proportional contribution of independent predictors in the multivariable model. RESULTS Size (>10 mm), aneurysm rupture, stent assistance, and posttreatment degree of aneurysm occlusion were independently associated with retreatment, whereas intraluminal thrombosis and flow diversion demonstrated a trend toward retreatment. The Aneurysm Recanalization Stratification Scale was constructed by assigning the following weights to statistically and clinically significant predictors: aneurysm-specific factors: size (>10 mm), 2 points; rupture, 2 points; presence of thrombus, 2 points. Treatment-related factors were stent assistance, -1 point; flow diversion, -2 points; Raymond Roy occlusion class 2, 1 point; Raymond Roy occlusion class 3, 2 points. This scale demonstrated good discrimination with a C-statistic of 0.799. CONCLUSION Surgical decision making and patient-centered informed consent require comprehensive and accessible information on treatment efficacy. We constructed the Aneurysm Recanalization Stratification Scale to enhance this decision-making process. This is the first comprehensive model that has been developed to quantitatively predict the risk of retreatment after endovascular therapy.

Association of nosocomial infections with delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage

OBJECTIVE Delayed cerebral ischemia (DCI) is a recognized complication of aneurysmal subarachnoid hemorrhage (aSAH) that contributes to poor outcome. This study seeks to determine the effect of nosocomial infection on the incidence of DCI and patient outcome. METHODS An exploratory analysis was performed on 156 patients with aSAH enrolled in the Cerebral Aneurysm Renin Angiotensin System study. Clinical and radiographic data were analyzed with univariate analysis to detect risk factors for the development of DCI and poor outcome. Multivariate logistic regression was performed to identify independent predictors of DCI. RESULTS One hundred fifty-three patients with aSAH were included. DCI was identified in 32 patients (20.9%). Nosocomial infection (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.09-11.2, p = 0.04), ventriculitis (OR 25.3, 95% CI 1.39-458.7, p = 0.03), aneurysm re-rupture (OR 7.55, 95% CI 1.02-55.7, p = 0.05), and clinical vasospasm (OR 43.4, 95% CI 13.1-143.4, p < 0.01) were independently associated with the development of DCI. Diagnosis of nosocomial infection preceded the diagnosis of DCI in 15 (71.4%) of 21 patients. Patients diagnosed with nosocomial infection experienced significantly worse outcomes as measured by the modified Rankin Scale score at discharge and 1 year (p < 0.01 and p = 0.03, respectively). CONCLUSIONS Nosocomial infection is independently associated with DCI. This association is hypothesized to be partly causative through the exacerbation of systemic inflammation leading to thrombosis and subsequent ischemia.

External validation of the Practical Risk Chart for the prediction of delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage

OBJECTIVE Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) occurs in approximately 30% of patients. The Practical Risk Chart was developed to predict DCI based on admission characteristics; the authors seek to externally validate and critically appraise this prediction tool. METHODS A prospective cohort of aSAH patients was used to externally validate the previously published Practical Risk Chart. The model consists of 4 variables: clinical condition on admission, amount of cisternal and intraventricular blood on CT, and age. External validity was assessed using logistic regression. Model discrimination was evaluated using the area under the receiver operating characteristic curve (AUC). RESULTS In a cohort of 125 patients with aSAH, the Practical Risk Chart adequately predicted DCI, with an AUC of 0.66 (95% CI 0.55-0.77). Clinical grade on admission and amount of intracranial blood on CT were the strongest predictors of DCI and clinical vasospasm. The best-fit model used a combination of the Hunt and Hess grade and the modified Fisher scale to yield an AUC of 0.76 (95% CI 0.675-0.85) and 0.70 (95% CI 0.602-0.8) for the prediction of DCI and clinical vasospasm, respectively. CONCLUSIONS The Practical Risk Chart adequately predicts the risk of DCI following aSAH. However, the best-fit model represents a simpler stratification scheme, using only the Hunt and Hess grade and the modified Fisher scale, and produces a comparable AUC.

Documentation of Improved Outcomes for Intracranial Aneurysm Management Over a 15-Year Interval

Background and Purpose— Despite rapid advancements in intracranial aneurysm management, there is no evidence as of yet that this has translated into improvement in overall prognosis. Methods— We compared 2 periods of aneurysm management, 1998 to 2003 (n=1023 aneurysms) and 2007 to 2013 (n=1499 aneurysms), at a single, high-volume neurovascular center. Our outcome of interest was low or moderate disability (Glasgow Outcome Scale score of 4 or 5) at 6 months or more post treatment. Results— There were significant improvements in outcome for surgical, endovascular, and overall treatment of unruptured (adjusted odds ratio [OR], 2.33; P=0.0091; adjusted OR, 4.40; P=0.0271; and adjusted OR, 2.58; P=0.0008, respectively) and ruptured (adjusted OR, 3.18; P=0.0004; adjusted OR, 3.54; P=0.0001; and adjusted OR, 3.11; P<0.0001, respectively) aneurysms from the first to the second time period. In 2007 to 2013, the proportion of cases with low or moderate disability at 6 months post subarachnoid hemorrhage was 75.6% for surgical clipping and 76.6% for endovascular therapy. Conclusions— We report significantly improved outcomes over time for overall aneurysm management and for multiple patient subgroups, associated with increased usage of endovascular therapy.

Corrective spinal surgery may be protective against stroke in patients with blunt traumatic vertebral artery occlusion

OBJECT Approximately 10% of patients with blunt traumatic extracranial cerebrovascular injury have a complete occlusion of the vertebral artery (VA). Ischemic stroke due to embolization of thrombus from an occluded VA following cervical spine surgery has been observed. The risk of ischemic stroke with cervical spine surgery in the presence of an occluded VA, however, has never been determined. METHODS A retrospective chart review of 52 patients with a VA occlusion following a blunt trauma was performed. Clinical and radiographic characteristics were collected and analyzed. RESULTS Ten patients (19.2%) suffered an ischemic stroke attributable to a traumatic VA occlusion. Univariate analysis demonstrated that patients with ischemic stroke were significantly older (p = 0.042) and had a lower rate of cervical spine surgery (p < 0.005). Multivariate analysis found cervical spine surgery to be protective against ischemic stroke (OR 0.049 [95% CI 0.014-0.167], p = 0.014); increasing age and bilateral VA injury (bilateral occlusion or unilateral occlusion with contralateral dissection) were risk factors for ischemic stroke (OR 1.05 [95% CI1.02-1.07], p = 0.065 and OR 13.2 [95% CI 2.98-58.9], p = 0.084, respectively). CONCLUSIONS Traumatic VA occlusion is associated with a risk of ischemic stroke and mortality. Corrective cervical spine surgery potentially decreases the risk of ischemic stroke by stabilizing the spine and thereby reducing motion across the occluded segment of the VA and preventing embolization of thrombus. While a high stoke risk may be inherent to the disease, novel therapies should be investigated.

Epidural Bovine Pericardium Facilitates Dissection During Cranioplasty: A Technical Note

BACKGROUND AND OBJECTIVE Adhesions and scarring of the subcutaneous tissue to the dura mater or dural substitute often complicate cranioplasty. We present our experience with epidural bovine pericardium as a barrier membrane to minimize adhesions and facilitate separation of tissue layers. METHODS A cohort of patients who underwent decompressive craniectomy and subsequent cranioplasty at a major academic institution in the United States from August 2007 to October 2013 and had epidural bovine pericardium placed as a barrier membrane was retrospectively reviewed. Medical records and imaging studies were reviewed for a number of variables including presence of adhesions, infection, contusions, and operative complications. RESULTS Twenty-nine patients (male-to-female = 1:1.1; mean age 45 ± 14.7 years) who underwent decompressive craniectomy with placement of epidural bovine pericardium with subsequent cranioplasty were identified. The median interval between craniectomy and cranioplasty was 64 days, and autologous bone was used for cranioplasty in 86.2% of cases. The average size of cranial defect was 71.2 ± 28.5 cm(2). At the time of cranioplasty, no or minimal adhesions were found between the subcutaneous tissue and the epidural bovine pericardium. There were 2 (6.9%) infections, 2 (6.9%) patients had contusion after the cranioplasty, and no patient had a complication after cranioplasty that required reoperation. CONCLUSIONS Epidural bovine pericardium at the time of decompressive craniectomy facilitates dissection at the time of cranioplasty and is not associated with any additional risks.

Proposal of Venous Drainage-Based Classification System for Carotid Cavernous Fistulae With Validity Assessment in a Multicenter Cohort.

BACKGROUND Carotid cavernous fistulae (CCFs) are most commonly classified based on arterial supply. Symptomatology and treatment approach, however, are largely influenced by venous drainage. OBJECTIVE To propose an updated classification system using venous drainage. METHODS CCFs with posterior/inferior drainage only, posterior/inferior and anterior drainage, anterior drainage only, and retrograde drainage into cortical veins with/without other drainage channels were designated as types 1, 2, 3, and 4, respectively. CCFs involving a direct connection between the internal carotid artery and cavernous sinus were designated as type 5. This system was retrospectively applied to 29 CCF patients. RESULTS Our proposed classification was significantly associated with symptomatology (P < .001). Type 2 was significantly associated with coexisting ocular/orbital and cavernous symptoms only (P < .001), type 3 with ocular/orbital symptoms only (P < .01), and type 4 demonstrated cortical symptoms with/without ocular/orbital and cavernous symptoms (P < .01), respectively. There was a significant association of our classification system with the endovascular treatment approach (P < .001). Types 1 and 2 were significantly associated with endovascular treatment through the inferior petrosal sinus (P < .01). Type 3 was significantly associated with endovascular treatment through the ophthalmic vein (P < .01) and type 5 with transarterial approach (P < .01), respectively. Types 2 (27.6%) and 3 (34.5%) were most prevalent in this series, whereas type 1 was rare (6.9%), suggesting that some degree of thrombosis is present, with implications for spontaneous resolution. Type 2 CCFs demonstrated a trend toward partial resolution after endovascular treatment (P = .07). CONCLUSION Our proposed classification system is easily applicable in clinical practice and demonstrates correlation with symptomatology, treatment approach, and outcome.