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Eric M. Deshaies, Sandeep Bagla, Celso Agner and Alan S. Boulos

Object

Coil embolization of aneurysms has been shown to be as safe and effective as surgical clip ligation, but has a higher recurrence rate. Advances in coil technology aim to reduce aneurysm recurrence by coating the devices with biological substances. An example of this is MicroVention's HydroCoil, which is a platinum coil coated with hydro-gel that improves filling volumes by swelling when it contacts blood. The goal of this study was to determine whether this new coil type significantly reduced or prevented recurrences of aneurysms.

Methods

The authors used three-dimensional computerized tomography angiography to determine aneurysm volumes accurately in 12 patients prior to coil embolization. The percentage filling volume was subsequently calculated for each aneurysm after treatment with HydroCoils and the immediate and 6-month follow-up angiographically confirmed occlusions were evaluated. The data demonstrated that both anterior and posterior intracranial aneurysms with diameters of 3 to 25 mm and volumes of 0.03 to 4.8 ml had filling volumes of 0.02 to 1.36 ml, resulting in filling volumes from 23% in a giant ophthalmic artery aneurysm to 80% in a small anterior communicating artery aneurysm. All of the aneurysms except for the giant one demonstrated stable occlusion on angiographic studies obtained at the 6-month follow-up review.

Conclusions

HydroCoil embolization of intracranial aneurysms is safe and effective for small, large, and very large aneurysms. The percentage filling volume is greater than that reported for bare platinum coils in every case except the giant aneurysm. Nevertheless, angiographically confirmed occlusion is not directly related to percentage filling volume, but rather to the ability to occlude the aneurysm neck.

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Eric M. Deshaies, Matthew A. Adamo and Alan S. Boulos

Object

The HydroCoil embolization system is a helical platinum coil coated with a polymeric hydrogel that expands when it contacts aqueous solutions to increase filling volumes, improve mesh stability, and possibly elicit a healing response within the aneurysm. In this paper, the authors report the 1-year recurrence and complication rates of 67 aneurysms embolized with the HydroCoil system.

Methods

Sixty-four consecutive patients (67 total aneurysms) with small (≤ 7 mm), large (8–15 mm), very large (16–24 mm), and giant (≥ 25 mm) aneurysms in the anterior and posterior intracranial circulations were treated with HydroCoils between March 2003 and September 2004. All aneurysms were embolized by the senior author (A.S.B) with HydroCoils alone or in combination with bare platinum coils, until either there was no further angiographic contrast filling of the aneurysm or the microcatheter was pushed out of the dome by the coil mass. Balloon assistance was used in three cases and combined Neuroform stent–coil embolization in eight other cases. To evaluate the safety and 1-year efficacy of the HydroCoil system, periprocedural complications were recorded, and angiographic recurrences were categorized using the Raymond–Roy Occlusion Classification (RROC) system.

The 1-year aneurysm recurrence rate independent of size was 15% in patients treated with HydroCoils. Seventy percent of the patients had stable occlusions. The recurrence rate for small aneurysms was 3.7%, and the combined recurrence rate for small and large aneurysms was 6%. Fifteen percent of the aneurysms initially categorized as RROC Type 2 or 3 with stasis of contrast material at the time of initial embolization improved in RROC type, allowing the authors to develop the aneurysm embolization grade to predict recurrence. The neurological complication rate was 14.9%, of which 4.5% represented permanent neurological deficits.

Conclusions

The HydroCoil embolization system is safe and provides excellent 1-year occlusion of small and large aneurysms with initial RROC Type 1, as well as those with RROC Types 2 and 3 with stasis of contrast material at the time of embolization. Very large and giant aneurysms were not as successfully occluded with this system. Treatment of large and giant internal carotid artery aneurysms was more likely to result in cranial nerve palsies and postembolization headaches than treatment in other locations. The aneurysm embolization grade the authors developed using the results of this study accurately predicted 1-year recurrence rates based on the immediate postembolization angiographic characteristics of the treated aneurysm.

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Celso Agner, Eric M. Deshaies, Gary L. Bernardini, A. John Popp and Alan S. Boulos

✓ In most cases of deep venous sinus thrombosis, systemic anticoagulation represents the initial treatment of choice for preventing propagation of a clot in the dural sinuses. In patients with deep or extensive venous sinus thrombosis, a combination of treatment modalities may be required including systemic anticoagulation, selective venous thrombolysis, and mechanical thrombectomy. In the current study the authors report on a patient who presented with the acute onset of headache, vomiting, a depressed level of consciousness, and a left hemiparesis and in whom a right middle cerebral artery (MCA) territory ischemic stroke with hemorrhagic conversion was initially diagnosed. Results of diagnostic cerebral angiography demonstrated a patent right MCA and a deep venous sinus thrombosis involving most of the dural sinuses. Despite adequate systemic heparinization, the patient's neurological condition deteriorated and direct administration of alteplase into the transverse sinus in conjunction with mechanical clot disruption using a coronary AngioJet was required. Venous flow was successfully reestablished in the deep and superficial venous sinuses by using a 0.014-in exchange wire routed from the right common femoral vein through the sinuses and out the left common femoral vein. Excellent angiographic results were obtained, and the patient had recovered completely by the 7-month follow up.

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John C. Dalfino, Matthew A. Adamo, Ravi H. Gandhi, Alan S. Boulos and John B. Waldman

Object

The optimal management of a ventriculoperitoneal shunt in the setting of acute, non–shunt related abdominal and pelvic infections is unknown. In the literature, distal shunt catheter reimplantation with or without a variable period of externalization has been recommended to prevent ascending ventriculitis. While this strategy is effective, there is little to almost no published data suggesting that it is necessary in all cases. Furthermore, it is not clear that shunt externalization to an external drainage bag during the treatment of non–shunt related peritonitis is any less likely to lead to ventriculitis than leaving the catheter in place. In the authors' experience, shunt externalization or revision during an episode of acute, non–shunt related peritonitis is unnecessary to prevent ventriculitis or chronic peritonitis.

Methods

In the present case series, the authors report on 7 patients whose shunts were left in the abdomen while they were treated for acute peritonitis. The patients were followed clinically for up to 21 months after the diagnosis to assess for evidence of recurrent abdominal infections, shunt infections, or shunt failure.

Results

In a follow-up period ranging from 13 to 22 months, no patient developed ventriculitis, required a shunt revision, or was unable to clear the peritoneal infection.

Conclusions

The results of this small series suggest that leaving the distal end of a shunt catheter in place in a patient with acute peritonitis is a reasonably safe choice in specific patients, provided the source of infection is aggressively treated with systemic antibiotics and local debridement when necessary.

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Akeel Merchant, Doniel Drazin, John Dalfino, Junichi Yamamoto and Alan S. Boulos

The authors report a case of restenosis in the bilateral internal carotid arteries (ICAs) following angioplasty for cerebral vasospasm. This 53-year-old woman suffering subarachnoid hemorrhage due to a ruptured posterior communicating artery aneurysm had severe vasospasm and underwent angioplasty of the left and right ICAs and middle cerebral arteries. Two months later, a follow-up CT angiogram revealed bilateral ICA stenoses.

Transluminal angioplasty leads to long-term connective tissue damage in the medial and adventitial layers from the disruption of the arrangement of collagen fibers due to stretching and tearing, resulting in loss of transmission of contractile forces. Furthermore, following endothelial cell denudation and stretching and rupture of internal elastic lamina from angioplasty, reendothelialization of the intimal layer composed of smooth muscle cells may also explain the contractile properties of restenosis. Other factors such as macrophage-induced inflammation and reactive oxygen species accumulation may also contribute to restenosis. This is the second reported case of restenosis following angioplasty to treat vasospasm, although restenosis is a known complication of angioplasty for treatment of atherosclerosis. In addition, this is the first case of restenosis in the bilateral ICAs following angioplasty for vasospasm. This report presents an illustrative case study and reviews the pathophysiology of angioplasty and restenosis.

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Tyler J. Kenning, Eric M. Deshaies, Matthew A. Adamo, John B. Waldman and Alan S. Boulos

Identifying a source of spontaneous subarachnoid hemorrhage (SAH) or intraventricular hemorrhage (IVH) in patients with negative results on cranial angiographic imaging can be a diagnostic challenge. The authors present the case of a 14-month-old girl who presented with lethargy and spontaneous SAH and IVH, and later became acutely paraplegic. Except for the SAH and IVH, findings on neuroimages of the brain were normal. Magnetic resonance imaging revealed an intramedullary thoracolumbar spinal cord hemorrhage that was found to be associated with arterialized veins intraoperatively. Catheter-based diagnostic angiography identified a spinal perimedullary macroarteriovenous fistula (macro-AVF) that was completely embolized with Onyx, negating the need for further surgical intervention. The authors believe this to be the first reported case of a thoracolumbar perimedullary macro-AVF presenting with SAH and IVH. In addition, descriptions of Onyx embolization of a spinal AVF in the literature are rare, especially in pediatric patients.

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Alan S. Boulos, Eric M. Deshaies, Jiang Qian and A. John Popp

✓ In this report, the authors discuss a novel use of intradural vertebral artery (VA) stent placement to protect a tumor-encased vessel from injury during lesion resection. The tumor was a rare foramen magnum region xanthogranuloma and a component of Erdheim—Chester disease (ECD). This 64-year-old man presented with large masses encasing and compressing the intracranial segments of each VA. Preoperatively, a left VA stent was placed to protect the arterial wall during resection of the tumor. Histopathological study results on the subtotally resected mass were consistent with xanthogranuloma, a rare benign histiocytic tumor frequently occurring in patients with ECD. Further radiographic evaluation in the patient revealed an osteolytic lesion of the eleventh thoracic vertebra supporting the diagnosis of ECD disease. Based on this case study, the authors recommend the following: 1) tumor-encased vessels can be protected preoperatively by stent placement to assist with tumor debulking; and 2) patients diagnosed with a xanthogranuloma should be evaluated for multisystem involvement consistent with ECD.

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Tyler J. Kenning, M. Reid Gooch, Ravi H. Gandhi, M. Parvez Shaikh, Alan S. Boulos and John W. German

Object

Recent randomized trials have demonstrated a positive role (improved survival) in patients treated with cranial decompression for malignant cerebral infarction. However, many variables regarding operative decompression in this setting remain to be determined. Hinge craniotomy is an alternative to decompressive craniectomy, but its role in space-occupying cerebral infarctions has not been delineated. The objective of this study was to compare the authors' experiences with these 2 procedures in the management of space-occupying cerebral infarctions to determine the efficacy of each.

Methods

The authors conducted a retrospective review of 28 cases involving patients who underwent cranial decompression (hinge craniotomy in 9 cases, decompressive craniectomy in 19) for treatment of malignant intracranial hypertension after ischemic cerebral infarction.

Results

No significant differences were identified in baseline demographics, neurological examination, or Rotterdam score between the hinge craniotomy and decompressive craniectomy groups. Both treatments resulted in adequate control of intracranial pressure (ICP). The need for reoperation for persistent intracranial hypertension and duration of mechanical ventilation and intensive care unit stay were similar. Hospital survival was significantly higher in the decompressive craniectomy group (89% vs 56%), whereas long-term functional outcome was better in the hinge craniotomy group. Cranial defect size was comparable in the 2 groups. Postoperative imaging revealed a higher rate of subarachnoid hemorrhage, contusion/hematoma progression, and subdural effusions/hygromas after decompressive craniectomy. The requirement for cranial revision in survivors was higher for patients undergoing decompressive craniectomy (100%) than those undergoing hinge craniotomy (20%).

Conclusions

Hinge craniotomy appears to be at least as good as decompressive craniectomy in providing postoperative ICP control at a similar therapeutic index. Although the in-hospital mortality was higher in patients treated with hinge craniotomy, that procedure resulted in superior long-term functional outcomes and may help limit postoperative complications.

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Alan S. Boulos, Eric M. Deshaies, John C. Dalfino, Paul J. Feustel, A. John Popp and Doniel Drazin

Object

Tamoxifen has been shown to be a potent neuroprotectant against stroke in rodents. Because other neuroprotectant medications have failed in human trials, a study of tamoxifen in a large-animal model was necessary to further assess the drug's effectiveness. For this study, the authors developed an endovascular model of anterior circulation infarction in canines to mimic the human clinical condition. They assessed the following hypotheses: 1) that they will be able to consistently produce an internal carotid artery (ICA) terminus infarction and 2) that tamoxifen is an effective neuroprotectant against stroke in canines.

Methods

In 24 male beagles (weight 9–11 kg), bilateral femoral artery cutdowns were performed, and the vertebral artery and left ICA were each selectively catheterized. Under fluoroscopic guidance, a microcatheter was introduced via the vertebral artery, guiding the catheter into the basilar artery, posterior communicating artery, and ICA terminus. A 1-ml clot was injected in the terminus, occluding the middle cerebral artery (MCA) and anterior cerebral artery (ACA) origin. In the first 12 canines, the occlusions were confirmed by angiography. A Canine Stroke Score (CSS) was assigned (score range 0–18 [0 = intact on examination, 18 = comatose]). The animals were then killed and their brains stained with 2,3,5-triphenyltetrazolium chloride (TTC). The subsequent 12 canines underwent a blinded randomized study in which the authors compared the results of tamoxifen (5 mg/kg) infused intravenously 1 hour after clot injection with an equal volume of vehicle (dimethylsulfoxide). After 3 hours, the animals underwent MR imaging, were extubated, and clinical examinations were performed. The canines were killed at 8 hours after clot injection, and TTC staining was used.

Results

In the first group, infarct volume and CSSs were consistent with the extent of the occlusion of the angiographic vessels. An occlusion of the ACA, MCA, and posterior cerebral artery resulted in larger infarcts and higher stroke scores than occlusion of the ACA and MCA. In the second group, tamoxifen significantly reduced infarct size and improved clinical outcomes. In tamoxifen-treated animals, the mean infarct volume reduction was 40% (p < 0.05) and the mean CSS was significantly less than vehicle-treated animals (p < 0.001). There were significant correlations among MR imaging-determined volume, TTC-determined volume, and neurological clinical outcome (p < 0.05).

Conclusions

Using this endovascular model of stroke, the authors were able to consistently produce an infarction in the canines that was similar in scope to a carotid terminus occlusion in humans. Also, angiography could predict subsequent clinical course and infarct size. Tamoxifen was effective at significantly improving the canine neurological deficits and reducing the size of the stroke. This study took the first step in demonstrating the effectiveness of a promising human neuroprotectant in a large animal.

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Ricardo A. Hanel, Alan S. Boulos, Eric G. Sauvageau, Elad I. Levy, Lee R. Guterman and L. Nelson Hopkins

Vertebrobasilar nonsaccular aneurysms represent a small subset of intracranial aneurysms and usually are among the most challenging to be treated. The aim of this article was to review the literature and summarize the experience in the treatment of these lesions with endovascular approaches. The method of stent implantation as it is performed at the authors' institution, including options available for vertebral artery access, is described. Practitioners involved in the treatment of these lesions should be aware of the potential application of intravascular stent placement as well as the associated postprocedure risks and potential complications.