Karam Moon

Critical assessment of complications associated with use of the Pipeline Embolization Device

Background The Pipeline Embolization Device (PED) has become an important tool in the treatment of complex cerebrovascular pathology since it was approved by the Food and Drug Administration in April 2011. Objective To determine the overall complication rate (permanent and transient) associated with the use of this new device from a single institution. Methods We retrospectively examined a prospectively maintained database of our patients treated with the PED since its availability to the current time. 126 patients (24 men, 102 women; age range 14–83 years, mean 59.8 years) were treated for a total of 137 intracranial aneurysms, one cervical internal carotid artery dissection, one cervical vertebral artery dissection, and one carotid-cavernous fistula with a total of 217 PEDs (1.72 PED/patient). Results A total of 40 complications were experienced by 33 patients in our cohort. Four complications (4/126, 3.2%) in four patients were permanent, resulting in three deaths and one permanent disability. The other 36 complications (28.6%) occurred in 29 patients, all of whom went on to recover completely. The total complication rate associated with the use of the PED was 31.7% (40/126). Conclusions Despite a low rate of permanent complications associated with the PED in this series, the total complication rate was high. This finding supports the conclusion that this device should be reserved for the most challenging aneurysms. Patients should be advised of this higher rate of transient periprocedural complications. Trial registration number IRB#:14BN027 Q7.

Treatment of ophthalmic segment carotid aneurysms using the pipeline embolization device: clinical and angiographic follow-up

Abstract Objectives: Aneurysms of the ophthalmic segment of the internal carotid artery (ICA) often present unique challenges to endovascular treatment due to their proximity to or involvement of the ophthalmic artery, and the subsequent risk of post-operative visual complications. The pipeline embolization device (PED) represents a paradigm shift and promising new therapy in the treatment of intracranial aneurysms. We reviewed the ophthalmic segment ICA aneurysms treated with the PED at Barrow Neurological Institute (BNI) to report outcome data, including patency of the ophthalmic artery and visual complications. Methods: The prospectively maintained BNI endovascular database was reviewed for all patients with ophthalmic segment ICA aneurysms treated with the PED since May 2011. Patient charts and digital subtraction angiograms were reviewed to report angiographic outcomes and visual complications. Only patients with at least 6 months of follow-up were included in the analysis. Results: Of 30 patients treated with ophthalmic segment aneurysms during the study period, sufficient follow-up was available for 29 patients with 38 aneurysms, all of which were treated electively. The PED was successfully deployed for all lesions, with 92·1% complete or near-complete obliteration rate at angiographic follow-up. All but one patient were found to have a patent ophthalmic artery at short-term follow-up and 100% of patients retained intact vision. Five patients had minor periprocedural hemorrhagic complications but no permanent morbidities. There were no intracranial hemorrhages, thromboembolic phenomena, vessel dissections, or mortalities. Conclusion: Treatment of ophthalmic segment ICA aneurysms with the PED is safe and effective at short-term follow-up.

Safety and Efficacy of Surgical Resection of Unruptured Low-grade Arteriovenous Malformations From the Modern Decade.

BACKGROUND Recent studies have questioned the utility of surgical resection of unruptured brain arteriovenous malformations (bAVMs). OBJECTIVE We performed an assessment of outcomes and complications of surgical resection of low-grade bAVMs (Spetzler-Martin grade I or II) at a single high-volume neurosurgical center. METHODS We reviewed all unruptured low-grade bAVMs treated with surgery (with or without preoperative embolization) between January 2004 and January 2014. Stroke rate, mortality, and clinical and radiographic outcomes were examined. RESULTS Of 95 patients treated surgically, 85 (25 grade I, 60 grade II) met inclusion criteria, and all achieved radiographic cure postoperatively. Ten patients (11.8%) were lost to follow-up; the mean follow-up of the remaining 85 was 3.3 years. Three patients (3.5%) with grade II bAVMs experienced a stroke; no patients died. Although 20 patients (23.5%) had temporary postoperative neurological deficit, only 3 (3.5%) had new clinical impairment (modified Rankin Scale score ≥2) at last follow-up. Eight of the 13 patients (61.5%) with preexisting clinical impairment had improved modified Rankin Scale scores of 0 or 1; and 17 of 30 patients (56.7%) with preoperative seizures were seizure-free without antiepileptic medication postoperatively. No significant differences existed in stroke rate or clinical outcome between grades I and II patients at follow-up (Fisher exact test, P = .55 and P > .99, respectively). CONCLUSION Surgical resection of low-grade unruptured bAVMs is safe, with a high rate of improvement in functional status and seizure reduction. Although transient postoperative neurological deficit was observed in some patients, permanent treatment-related neurological morbidity was rare. ABBREVIATIONS ARUBA, A Randomized Trial of Unruptured Brain Arteriovenous MalformationsbAVM, brain arteriovenous malformationmRS, modified Rankin Scale.

Posterior Inferior Cerebellar Artery Patency after Flow-Diverting Stent Treatment

BACKGROUND AND PURPOSE: The rate of PICA occlusion after flow-diverting stent placement for vertebral and vertebrobasilar artery aneurysms is not known. The purpose of this study is to determine the medium-term rate of PICA patency and risk factors for occlusion after such aneurysm treatment. MATERIALS AND METHODS: Patients were identified who had vertebral or vertebrobasilar artery aneurysms and who were treated by placing a flow-diverting stent across the PICA ostium. Demographic and procedural factors associated with stent placement were recorded. Patency of the PICA was evaluated immediately after stent placement and on follow-up angiography. RESULTS: Thirteen patients with vertebral or vertebrobasilar artery aneurysms were treated in the study period, of whom 4 presented with subarachnoid hemorrhage. The average number of devices that spanned the PICA ostium was 1.77 (range, 1–3), with no immediate PICA occlusions. There were no postoperative strokes in the treated PICA territory, although there was 1 contralateral PICA-territory stroke of unclear etiology without clinical sequelae. In 11 patients with follow-up angiography at a mean of 10.6 months (range, 0.67–27.9 months), the PICA patency rate remained 100%. CONCLUSIONS: Flow-diverting stent placement across the PICA ostium in the treatment of vertebral and vertebrobasilar artery aneurysms may not result in immediate or midterm PICA occlusion.

Balloon remodeling of complex anterior communicating artery aneurysms: technical considerations and complications

Introduction Reports of the limitations and feasibility of balloon remodeling for treatment of complex anterior communicating artery (ACoA) aneurysms are scarce. Methods Ninety-nine patients were treated with balloon-assisted coil embolization for ACoA aneurysms between August 2004 and October 2012. Records were reviewed for aneurysm characteristics, balloon trajectory (vessel and side), bilateral access, treatment-related complications, and aneurysm recurrence determined by magnetic resonance angiography (MRA). Morphological outcomes following treatment were categorized into Raymond class I, II, or III. Results Fifty-three aneurysms (53.5%) were unruptured and 46 (46.4%) were ruptured. Aneurysmal occlusion (Raymond I or II) was achieved in 89 patients (89.9%); three (3.0%) were incompletely embolized and treatment was aborted in six (6.1%). Balloon trajectories were from the A1 to either the ipsilateral or contralateral A2. In 17 cases (17.2%), bilateral A1 access was used to achieve balloon protection of the contralateral A2. In four cases (4.0%), balloon remodeling was aborted due to technical difficulty. There were 15 (15.2%) treatment-related complications; five (5.1%) were intraoperative ruptures, one of which resulted in a neurological deficit and another in death. All other complications were clinically silent, producing a permanent complication rate of 2.0%. Mean radiographic follow-up was 2.5 years, and six patients (6.1%) were retreated for recurrence or known remnant. Conclusions Balloon remodeling should be considered for broad-based complex ACoA aneurysms. This technique provides a high rate of aneurysm occlusion with an acceptable complication profile, and avoids the need for dual antiplatelet therapy. The balloon trajectory will depend on aneurysm morphology and bilateral access may be useful in selected cases.

Brain arteriovenous malformations

An arteriovenous malformation is a tangle of dysplastic vessels (nidus) fed by arteries and drained by veins without intervening capillaries, forming a high-flow, low-resistance shunt between the arterial and venous systems. Arteriovenous malformations in the brain have a low estimated prevalence but are an important cause of intracerebral haemorrhage in young adults. For previously unruptured malformations, bleeding rates are approximately 1% per year. Once ruptured, the subsequent risk increases fivefold, depending on associated aneurysms, deep locations, deep drainage and increasing age. Recent findings from novel animal models and genetic studies suggest that arteriovenous malformations, which were long considered congenital, arise from aberrant vasculogenesis, genetic mutations and/or angiogenesis after injury. The phenotypical characteristics of arteriovenous malformations differ among age groups, with fistulous lesions in children and nidal lesions in adults. Diagnosis mainly involves imaging techniques, including CT, MRI and angiography. Management includes observation, microsurgical resection, endovascular embolization and stereotactic radiosurgery, alone or in any combination. There is little consensus on how to manage patients with unruptured malformations; recent studies have shown that patients managed medically fared better than those with intervention at short-term follow-up. By contrast, interventional treatment is preferred following a ruptured malformation to prevent rehaemorrhage. Management continues to evolve as new mechanistic discoveries and reliable animal models raise the possibility of developing drugs that might prevent the formation of arteriovenous malformations, induce obliteration and/or stabilize vessels to reduce rupture risk. For an illustrated summary of this Primer, visit: http://go.nature.com/TMoAdn

Surgical and Endovascular Treatment of Pediatric Spinal Arteriovenous Malformations

OBJECTIVE Pediatric spinal arteriovenous malformations (AVMs) are rare and complex lesions to treat. There are few reports of the endovascular and microsurgical treatment of these lesions in the pediatric population, and the treatment outcomes of these patients are not well described. The aim of this study was the clinical and radiographic outcomes of spinal AVMs in pediatric patients treated via endovascular and microsurgical modalities. METHODS We identified nine children (5 boys, 4 girls; average age 11 years, range 3-17 years) treated for spinal AVMs between 1998 and 2010. Their charts were reviewed. RESULTS Spinal AVMs most frequently involved the thoracic spinal cord. Four patients had associated Klippel-Trènaunay-Weber syndrome and one had hereditary hemorrhagic telangiectasia. There were two intramedullary, four conus medullaris, and three mixed extradural-intradural lesions. The most common presenting signs and symptoms were subarachnoid hemorrhage (n = 3) and paraparesis (n = 5). Endovascular intervention was used exclusively in two patients, and combined endovascular and microsurgical intervention was used in four patients. Surgery was the sole treatment in three patients with excellent results. There were two treatment-related complications: one case of subarachnoid hemorrhage and one case of scrotal swelling. The mean follow-up was 28.5 months and the median was 8 months (range, 1-65 months). The mean pretreatment World Health Organization (WHO)/Zubrod score was 2.4 (range, 1-4), and the mean post-treatment score was 1.4 (range, 0-4). One patient (11%) had a recurrence. CONCLUSIONS Pediatric spinal AVMs require complex combined microsurgical and endovascular techniques to achieve favorable outcomes.

Incidence and predictors of dural venous sinus pressure gradient in idiopathic intracranial hypertension and non-idiopathic intracranial hypertension headache patients: results from 164 cerebral venograms

OBJECTIVE Cerebral venous pressure gradient (CVPG) from dural venous sinus stenosis is implicated in headache syndromes such as idiopathic intracranial hypertension (IIH). The incidence of CVPG in headache patients has not been reported. METHODS The authors reviewed all cerebral venograms with manometry performed for headache between January 2008 and May 2015. Patient demographics, headache etiology, intracranial pressure (ICP) measurements, and radiographic and manometric results were recorded. CVPG was defined as a difference ≥ 8 mm Hg by venographic manometry. RESULTS One hundred sixty-four venograms were performed in 155 patients. There were no procedural complications. Ninety-six procedures (58.5%) were for patients with IIH. The overall incidence of CVPG was 25.6% (42 of 164 procedures): 35.4% (34 of 96 procedures) in IIH patients and 11.8% (8 of 68 procedures) in non-IIH patients. Sixty procedures (36.6%) were performed in patients with preexisting shunts. Seventy-seven patients (49.7%) had procedures preceded by an ICP measurement within 4 weeks of venography, and in 66 (85.7%) of these patients, the ICP had been found to be elevated. CVPG was seen in 8.3% (n = 5) of the procedures in the 60 patients with a preexisting shunt and in 0% (n = 0) of the 11 procedures in the 77 patients with normal ICP (p < 0.001 for both). Noninvasive imaging (MR venography, CT venography) was assessed prior to venography in 112 (68.3%) of 164 cases, and dural venous sinus abnormalities were demonstrated in 73 (65.2%) of these cases; there was a trend toward CVPG (p = 0.07). Multivariate analysis demonstrated an increased likelihood of CVPG in patients with IIH (OR 4.97, 95% CI 1.71-14.47) and a decreased likelihood in patients with a preexisting shunt (OR 0.09, 95% CI 0.02-0.44). CONCLUSIONS CVPG is uncommon in IIH patients, rare in those with preexisting shunts, and absent in those with normal ICP.

Clinical and Anatomic Insights From a Series of Ethmoidal Dural Arteriovenous Fistulas at Barrow Neurological Institute

BACKGROUND Ethmoidal dural arteriovenous fistulas (dAVFs) have a malignant natural history and an anatomy that make endovascular therapy challenging. Their uniqueness begs for stratified analyses, but this has largely been precluded by their rarity. We sought to summarize the anatomic, presentation, treatment approaches, and clinical outcomes of patients with these lesions. METHODS We reviewed our prospectively maintained institutional database to identify patients diagnosed with ethmoidal dAVFs from January 1, 2000, to December 31, 2015. We evaluated demographic, presentation, angiographic, treatment, and follow-up data. RESULTS In total, 27 patients with ethmoidal dAVFs underwent endovascular and/or surgical treatment. Mean patient age was 62 years old and there was a male sex predilection (67% men; 2:1 male-female ratio). All dAVFs exhibited direct cortical venous drainage; venous ectasia was present in 59% of cases. Of the dAVFs, 30% drained posteriorly into the basal vein of Rosenthal or the sylvian veins. Embolization with casting of the draining vein was successful in 2 of 9 cases (22%), including 1 successful transvenous case. There were no clinical or permanent complications from embolization; specifically, no patients experienced visual loss after treatment. Surgical treatment with successful dAVF obliteration was carried out in 24 of 24 patients (100%). One patient declined surgical treatment after attempted endovascular embolization. There were no permanent complications after surgical treatment and no cases of wound infection or cerebrospinal fluid leakage. CONCLUSIONS Surgical disconnection remains the gold standard in the treatment of ethmoidal dAVFs. Embolization is a consideration for well-selected cases with favorable arterial or venous access anatomy.

Methamphetamine use is an independent predictor of poor outcome after aneurysmal subarachnoid hemorrhage

Background Clinical outcomes of methamphetamine users with aneurysmal subarachnoid hemorrhage (aSAH) are unknown. Objective To analyze differences in presentation, in-hospital morbidity, and outcomes between methamphetamine users and non-users. Methods All 472 patients included in the Barrow Ruptured Aneurysm Trial from 2003 to 2007 were reviewed. Patients with 1- and 3-year follow-up were included in this analysis (n=398). Methamphetamine users were identified as patients who provided a history of methamphetamine use on admission or tested positive on urine toxicology testing. Methamphetamine users were compared with non-users using univariate analysis. Outcomes were then analyzed using multivariate logistic regression models for demographic characteristics, medical comorbidities, radiographic and clinical presentation, and vasospasm. Results Thirty-one patients (7.8%) were identified as methamphetamine users in this cohort. Methamphetamine users were younger than non-users (mean age 42.8 vs 55 years, p<0.001). In multivariate logistic regression models, methamphetamine use was an independent predictor of poor Glasgow Outcome Scale score at both 1 year (OR=5.02; 95% CI 1.03 to 24.48; p<0.05) and 3 years (OR=7.18; 95% CI 1.73 to 29.87; p=0.007). Other independent predictors in this model included older age, clinical vasospasm, diabetes, and aneurysm size. Cocaine and tobacco use were not significantly associated with poor outcome in our cohort. Methamphetamine use was not significantly associated with vasospasm, higher Fisher or Hunt and Hess grade, or intraparenchymal hemorrhage/intraventricular hemorrhage. Conclusions Methamphetamine users have significantly worse outcomes at 1 and 3 years following aSAH. Further analysis is necessary to understand the pathological response associated with methamphetamine use in this setting.