The use of flow-diverting stents for intracranial aneurysms has become more prevalent, and flow diverters are now routinely used beyond their initial scope of approval at the proximal internal carotid artery. Although flow diversion for the treatment of cerebral aneurysms is becoming more commonplace, there have been no reports of its use to treat flow-related cerebral aneurysms associated with arteriovenous malformations (AVMs). The authors report the cases of 2 patients whose AVM-associated aneurysms were managed with flow diversion. A 40-year-old woman presented with a history of headaches that led to the identification of an unruptured Spetzler-Martin Grade V, right parietooccipital AVM associated with 3 aneurysms of the ipsilateral internal carotid artery. Initial attempts at balloon-assisted coil embolization of the aneurysms were unsuccessful. The patient underwent placement of a flow-diverting stent across the diseased vessel; a 6-month follow-up angiogram demonstrated complete occlusion of the aneurysms. In the second case, a 57-year-old man presented with new-onset seizures, and an unruptured Spetzler-Martin Grade V, right frontal AVM associated with an irregular, wide-necked anterior communicating artery aneurysm was identified. The patient underwent placement of a flow-diverting stent, and complete occlusion of the aneurysm was observed on a 7-month follow-up angiogram. These 2 cases illustrate the potential for use of flow diversion as a treatment strategy for feeding artery aneurysms associated with AVMs. Because of the need for dual antiplatelet medications after flow diversion in this patient population, however, this strategy should be used judiciously.
Craig Kilburg, Philipp Taussky, M. Yashar S. Kalani and Min S. Park
Daniel M. S. Raper, Nasser Mohammed, M. Yashar S. Kalani and Min S. Park
The preferred method for treating complex dural arteriovenous fistulae of the transverse and sigmoid sinuses is via endovascular, transarterial embolization using liquid embolysate. However, this treatment approach mandates access to distal dural feeding arteries that can be technically challenging by standard endovascular approaches. This video describes a left temporal craniotomy for direct stick microcatheterization of an endovascularly inaccessible distal posterior division of the middle meningeal artery for embolization of a complex left temporal dural arteriovenous fistula. The case was performed in the hybrid operative suite with biplane intraoperative angiography. Technical considerations, operative nuances, and outcomes are reviewed.
The video can be found here: https://youtu.be/Dnd4yHgaKcQ.
Nam Yoon, Aatman Shah, William T. Couldwell, M. Yashar S. Kalani and Min S. Park
Skull base meningiomas are technically challenging tumors to treat because of their deep vascular supply that can preclude early devascularization during resection. Preoperative embolization of these arterial feeders is thought to decrease blood loss and facilitate resection; however, given the complex and varied anatomy of these skull base lesions, preoperative embolization is not without risk. It is essential for both endovascular and skull base neurosurgeons to understand these risks in light of the potential benefits. The authors review the vascular anatomy of skull base meningiomas, indications for preoperative devascularization, endovascular techniques, and published results regarding embolization of these lesions.
Vijay M. Ravindra, Jayson A. Neil, Marcus D. Mazur, Min S. Park, William T. Couldwell and Philipp Taussky
The craniocervical junction (CCJ) functions within a complicated regional anatomy necessary to protect and support vital neurovascular structures. In select instances, vascular pathology can be attributed to this complicated interplay of motion and structure found within this narrow space. The authors report 3 cases of complex vascular pathology related to motion at the CCJ and detail the management of these cases. Two cases involved posterior circulation vascular compression syndromes, and one case involved a vascular anomaly and its relation to aneurysm formation and rupture. The patient in Case 1 was a 66-year-old man with a history of syncopal episodes resulting from the bilateral vertebral artery becoming occluded when he rotated his head. Successful microsurgical decompression at the skull base resulted in patent bilateral vertebral artery V3 segments upon head movement in all directions. The patient in Case 2 was a 53-year-old woman who underwent elective resection of a right temporal meningioma and who experienced postoperative drowsiness, dysphagia, and mild right-arm ataxia. Subsequent MRI demonstrated bilateral posterior inferior cerebel-lar artery (PICA) strokes. Cerebral angiography showed a single PICA, of extradural origin, supplying both cerebellar hemispheres. The PICA exhibited dynamic extradural compression when the patient rotated her head; the bilateral PICA strokes were due to head rotation during surgical positioning. In Case 3, a 37-year-old woman found unconscious in her home had diffuse subarachnoid hemorrhage and evidence of a right PICA aneurysm. A right far-lateral craniectomy was performed for aneurysm clipping, and she was found to have a dissecting aneurysm with an associated PICA originating extradurally. There was a shearing phenomenon of the extradural PICA along the dura of the foramen magnum, and this microtraumatic stress imposed on the vessel resulted in a dissecting aneurysm. This series of complex and unusual cases highlights the authors’ understanding of vascular pathology of the CCJ and its management.
Adam S. Arthur, Philipp Taussky, Min S. Park, Michael F. Stiefel and Robert H. Rosenwasser
Sauson Soldozy, John S. Costello, Pedro Norat, Jennifer D. Sokolowski, Kamron Soldozy, Min S. Park, Petr Tvrdik and M. Yashar S. Kalani
While the majority of cerebral revascularization advancements were made in the last century, it is worth noting the humble beginnings of vascular surgery throughout history to appreciate its progression and application to neurovascular pathology in the modern era. Nearly 5000 years of basic human inquiry into the vasculature and its role in neurological disease has resulted in the complex neurosurgical procedures used today to save and improve lives. This paper explores the story of the extracranial-intracranial approach to cerebral revascularization.
Ching-Jen Chen, Pedro Norat, Dale Ding, George A. C. Mendes, Petr Tvrdik, Min S. Park and M. Yashar Kalani
Endovascular embolization of brain arteriovenous malformations (AVMs) is conventionally performed from a transarterial approach. Transarterial AVM embolization can be a standalone treatment or, more commonly, used as a neoadjuvant therapy prior to microsurgery or stereotactic radiosurgery. In contrast to the transarterial approach, curative embolization of AVMs may be more readily achieved from a transvenous approach. Transvenous embolization is considered a salvage therapy in contemporary AVM management. Proposed indications for this approach include a small (diameter < 3 cm) and compact AVM nidus, deep AVM location, hemorrhagic presentation, single draining vein, lack of an accessible arterial pedicle, exclusive arterial supply by perforators, and en passage feeding arteries. Available studies of transvenous AVM embolization in the literature have reported high complete obliteration rates, with reasonably low complication rates. However, evaluating the efficacy and safety of this approach is challenging due to the limited number of published cases. In this review the authors describe the technical considerations, indications, and outcomes of transvenous AVM embolization.
Shervin R. Dashti, Humain Baharvahdat, Robert F. Spetzler, Eric Sauvageau, Steven W. Chang, Michael F. Stiefel, Min S. Park and Nicholas C. Bambakidis
Postoperative infection after cranial surgery is a serious complication that requires immediate recognition and treatment. In certain cases such as postoperative meningitis, the patient can be treated with antibiotics only. In cases that involve a bone flap infection, subdural empyema, or cerebral abscess, however, reoperation is often needed. There has been significant disagreement regarding the incidence of postoperative central nervous system (CNS) infections following cranial surgery. In this paper the authors' goal was to perform a retrospective review of the incidence of CNS infection after cranial surgery at their institution. They focused their review on those patients who required repeated surgery to treat the infection.
The authors reviewed the medical records and imaging studies in all patients who underwent a craniotomy or stereotactic drainage for CNS infection over the past 10 years. Subgroup analysis was then performed in patients whose infection was a result of a previous cranial operation to determine the incidence, factors associated with infection, and the type of infectious organism. Patients treated nonoperatively (that is, those who received intravenous antibiotics for postoperative meningitis or cellulitis) were not included. Patients treated for wound infection without intracranial pus were also not included.
During the study period from January 1997 through December 2007, ~ 16,540 cranial surgeries were performed by 25 neurosurgeons. These included elective as well as emergency and trauma cases. Of these cases 82 (0.5%) were performed to treat postoperative infection in 50 patients. All 50 patients underwent their original surgery at the authors' institution. The median age was 51 years (range 2–74 years). There were 26 male and 24 female patients.
The most common offending organism was methicillin-sensitive Staphylococcus aureus, which was found in 10 of 50 patients. Gram-negative rods were found in 15 patients. Multiple organisms were identified in specimens obtained in 5 patients. Six patients had negative cultures. Most craniotomies leading to subsequent infection were performed for tumors or other mass lesions (23 of 50 patients), followed by craniotomies for hemorrhage and vascular lesions. Almost half of the patients underwent > 1 cranial operation before presenting with infection.
Postoperative infection after cranial surgery is an important phenomenon that needs immediate recognition. Even with strict adherence to sterile techniques and administration of antibiotic prophylaxis, a small percentage of these patients will develop an infection severe enough to require reoperation.
Adeel Ilyas, Ching-Jen Chen, Dale Ding, Andrew Romeo, Thomas J. Buell, Tony R. Wang, M. Yashar S. Kalani and Min S. Park
Stroke is one of the leading causes of death worldwide and a significant source of long-term morbidity. Unfortunately, a substantial number of stroke patients either are ineligible or do not significantly benefit from contemporary medical and interventional therapies. To address this void, investigators recently made technological advances to render transcranial MR-guided, high-intensity focused ultrasound (MRg-HIFU) sonolysis a potential therapeutic option for both acute ischemic stroke (AIS)—as an alternative for patients with emergent large-vessel occlusion (ELVO) who are ineligible for endovascular mechanical thrombectomy (EMT) or as salvage therapy for patients in whom EMT fails—and intracerebral hemorrhage (ICH)—as a neoadjuvant means of clot lysis prior to surgical evacuation. Herein, the authors review the technological principles behind MRg-HIFU sonolysis, its results in in vitro and in vivo stroke models, and its potential clinical applications. As a noninvasive transcranial technique that affords rapid clot lysis, MRg-HIFU thrombolysis may develop into a therapeutic option for patients with AIS or ICH. However, additional studies of transcranial MRg-HIFU are necessary to ascertain the merit of this treatment approach for thrombolysis in both AIS and ICH, as well as its technical limitations and risks.
Shervin R. Dashti, Humain Baharvahdat, Eric Sauvageau, Steven W. Chang, Michael F. Stiefel, Min S. Park, Robert F. Spetzler and Nicholas C. Bambakidis
✓ Brain abscess is a rare but very dangerous neurosurgical lesion. Prompt diagnosis and emergency surgical evacuation are the hallmarks of therapy. Brain abscess following ischemic and hemorrhagic stroke is a rare entity. These cases are often preceded by episodes of bacteremia, sepsis, and local infection. The authors report the case of a 30-year-old woman who presented with a cerebral abscess at the site of a recent intraparenchymal hemorrhage.