Endovascular obliteration of wide-necked aneurysms may be precluded by the inability to navigate across the aneurysm neck. The authors present a technique in which a Hyperform balloon is inflated within the aneurysm and used as a contact surface to “bounce” the remodeling balloon across the aneurysm neck. They have successfully used this technique in 3 patients to efficiently overcome vessel tortuosity, aneurysmal dead space, and balloon prolapse, allowing for obliteration of large, wide-necked aneurysms.
Stacey Quintero Wolfe, Hamad Farhat, Roham Moftakhar, Mohamed Samy Elhammady and Mohammad Ali Aziz-Sultan
Mohamed Samy Elhammady, Stacey Quintero Wolfe, Hamad Farhat, Roham Moftakhar and Mohammad Ali Aziz-Sultan
The authors conducted a study to determine the safety and efficacy of embolization of carotid-cavernous fistulas (CCFs) with the ethylene vinyl alcohol copolymer, Onyx.
They prospectively collected data in all patients with CCFs who underwent Onyx-based embolization at their institution over a 3-year period. The type of fistula, route of embolization, viscosity of Onyx, additional use of coils, extent of embolization, procedural complications, and clinical follow-up were recorded.
A total of 12 patients (5 men and 7 women who were age 24–88 years) underwent embolization in which Onyx was used. There were 1 Barrow Type A, 1 Type B, 3 Type C, and 7 Type D fistulas. Embolization was performed via a transvenous route in 8 cases and a transarterial route in 4 cases. Onyx 34 was used in all but 2 cases: a direct Type A fistula embolized with Onyx 500 and an indirect Type C fistula embolized with Onyx 18. Adjuvant embolization with framing coils was performed in 7 cases. All procedures were completed in a single session. Immediate fistula obliteration was achieved in all cases. Clinical resolution of presenting symptoms occurred in 100% of the patients by 2 months. Neurological complications occurred in 3 patients. One patient developed a complete cranial nerve (CN) VII palsy that has not resolved. Two patients developed transient neuropathies—1 a Horner syndrome and partial CN VI palsy, and 1 a complete CN III and partial CN V palsy. Radiographic follow-up (mean 16 months, range 4–35 months) was available in 6 patients with complete resolution of the lesion in all.
Onyx is a liquid embolic agent that is effective in the treatment of CCFs but not without hazards. Postembolization cavernous sinus thrombosis and swelling may result in transient compressive cranial neuropathies. The inherent gradual polymerization properties of Onyx allow for casting of the cavernous sinus but may potentially result in deep penetration within arterial collaterals that can cause CN ischemia/infarction. Although not proven, the angiotoxic effects of dimethyl sulfoxide may also play a role in postembolization CN deficits.
Mohamed Samy Elhammady, Stacey Quintero Wolfe, Ramsey Ashour, Hamad Farhat, Roham Moftakhar, Baruch B. Lieber and Mohammad Ali Aziz-Sultan
The authors assessed the safety and efficacy of embolization of head, neck, and spinal tumors with Onyx and determined the correlation between tumor embolization and intraoperative blood loss.
The authors prospectively collected all head, neck, and spinal tumors embolized with Onyx at their institution over a 28-month period. Information on tumor type, location, extent of tumor devascularization, endovascular and surgical complications, and intraoperative estimated blood loss (EBL) was evaluated.
Forty-three patients with various head, neck, and spinal lesions underwent vascular tumor embolization with Onyx. Indications for embolization included uncontrolled tumor bleeding in 8 cases, elective preoperative devascularization in 34, and tumor-induced consumptive thrombocytopenia in 1 case. Embolization was performed via direct tumoral puncture in 14 cases and through the traditional transarterial route in the remaining lesions. Embolization was successful in ending uncontrolled tumor bleeding in all 8 cases and in reversing the consumptive coagulopathy in 1 case. Intraparenchymal penetration of embolic material was possible in all percutaneously embolized tumors and in 4 of the 20 tumors embolized preoperatively via the transarterial route. The mean percentage of devascularization in tumors with intraparenchymal penetration of Onyx was 90.3% compared with 83.7% in tumors without intraparenchymal penetration. The mean EBL with intraparenchymal penetration of Onyx was significantly lower than when there was no intraparenchymal penetration (459 vs 2698 ml; p = 0.0067). There were no neurological complications related to the embolization procedures.
Embolization of vascular tumors with Onyx can be performed safely but may not reach optimal effectiveness in reducing intraoperative EBL if the embolic material does not penetrate the tumor vasculature. In the authors' experience, the best method of intraparenchymal penetration is achieved with direct tumor puncture. Transarterial embolization may not result in tumor penetration, particularly when injected from a long distance through small caliber or slow flow vessels.
Stephan A. Munich, Lee A. Tan, Kiffon M. Keigher, Michael Chen, Roham Moftakhar and Demetrius K. Lopes
Vertebrobasilar fusiform aneurysms (VFAs) are rare lesions characterized by abnormal dilation and tortuosity of the vertebral and/or basilar arteries. Untreated, these aneurysms have a tendency to progress, often resulting in neurological symptoms or rupture leading to subarachnoid hemorrhage. The microsurgical treatment of these lesions can be difficult due to their location and the circumferential involvement of the arteries. These features make microsurgical treatment prone to high morbidity. The Pipeline Embolization Device (PED) has gained popularity for the treatment of aneurysms of the internal carotid artery. Its use in the posterior circulation has been limited, likely due to a fear of perforating artery occlusion.
The authors retrospectively reviewed their database of patients treated with the PED and identified 12 patients who had VFAs. The clinical features, complications, and outcomes of these patients were analyzed.
At an average follow-up of 11 months, the mean modified Rankin Scale score was 1.9. Complete aneurysm occlusion was seen in 90% of the patients with radiographic follow-up. Three patients suffered new neurological deficits postoperatively. One of these patients died, while the remaining 2 demonstrated significant clinical improvement at follow-up.
With attention to the anatomy of perforating arteries, staged contralateral vertebral artery sacrifice, and adequate platelet inhibition, PED may be an effective treatment option—alone or in a hybrid construct with stents of less coverage for VFAs—with an acceptable complication rate.
Brian P. Witwer, Roham Moftakhar, Khader M. Hasan, Praveen Deshmukh, Victor Haughton, Aaron Field, Konstantinos Arfanakis, Jane Noyes, Chad H. Moritz, M. Elizabeth Meyerand, Howard A. Rowley, Andrew L. Alexander and Behnam Badie
Object. Preserving vital cerebral function while maximizing tumor resection is a principal goal in surgical neurooncology. Although functional magnetic resonance imaging has been useful in the localization of eloquent cerebral cortex, this method does not provide information about the white matter tracts that may be involved in invasive, intrinsic brain tumors. Recently, diffusion-tensor (DT) imaging techniques have been used to map white matter tracts in the normal brain. The aim of this study was to demonstrate the role of DT imaging in preoperative mapping of white matter tracts in relation to cerebral neoplasms.
Methods. Nine patients with brain malignancies (one pilocytic astrocytoma, five oligodendrogliomas, one low-grade oligoastrocytoma, one Grade 4 astrocytoma, and one metastatic adenocarcinoma) underwent DT imaging examinations prior to tumor excision. Anatomical information about white matter tract location, orientation, and projections was obtained in every patient. Depending on the tumor type and location, evidence of white matter tract edema (two patients), infiltration (two patients), displacement (five patients), and disruption (two patients) could be assessed with the aid of DT imaging in each case.
Conclusions. Diffusion-tensor imaging allowed for visualization of white matter tracts and was found to be beneficial in the surgical planning for patients with intrinsic brain tumors. The authors' experience with DT imaging indicates that anatomically intact fibers may be present in abnormal-appearing areas of the brain. Whether resection of these involved fibers results in subtle postoperative neurological deficits requires further systematic study.
David A. Stidd, Joshua Wewel, Ali J. Ghods, Stephan Munich, Anthony Serici, Kiffon M. Keigher, Heike Theessen, Roham Moftakhar and Demetrius K. Lopes
Cerebrovascular lesions can have complicated abnormal anatomy that is not completely characterized by CT or MR angiography. Although 3D rotational angiography provides superior spatial and temporal resolution, catheter angiograms are not easily registered to the patient, limiting the use of these images as a source for neuronavigation. However, 3D digital subtraction angiography (DSA) contains not only vascular anatomy but also facial surface anatomy data. The authors report a novel technique to register 3D DSA images by using only the surface anatomy contained within the data set without having to fuse the DSA image set to other imaging modalities or use fiducial markers.
A cadaver model was first created to assess the accuracy of neuronavigation based on 3D DSA images registered by facial surface anatomy. A 3D DSA scan was obtained of a formalin-fixed cadaver head, with acquisitions of mask and contrast runs. The right common carotid artery was injected prior to the contrast run with a 45% contrast solution diluted with water-soluble red liquid latex. One week later, the head was registered to a neuronavigation system loaded with the 3D DSA images acquired earlier using facial surface anatomy. A right pterional craniotomy was performed and 10 different vascular landmarks were identified and measured for accuracy using the neuronavigation system. Neuronavigation based only on 3D DSA was then used to guide an open clipping procedure for a patient who presented with a ruptured distal lenticulostriate aneurysm.
The accuracy of the measurements for the cadaver model was 0.71 ± 0.25 mm (mean ± SE), which is superior to the 1.8–5 mm reported for neuronavigation. The 3D DSA–based navigation-assisted surgery for the distal lenticulostriate aneurysm aided in localization, resulting in a small craniotomy and minimal brain dissection.
This is the first example of frameless neuronavigation based on 3D catheter angiography registered by only the surface anatomy data contained within the 3D DSA image set. This is an easily applied technique that is beneficial for accurately locating vascular pathological entities and reducing the dissection burden of vascular lesions.