Advances in the Endovascular Management of Cerebrovascular Disease.

The field of endovascular neurosurgery has experienced remarkable progress over the last few decades. Endovascular treatments have continued to gain traction as the advancement of technology, technique, and procedural safety has allowed for the expansion of treatment indications of various cerebrovascular pathologies. Interventions such as the coiling of intracranial aneurysms, carotid artery stenting, mechanical thrombectomy in the setting of ischemic stroke, and endovascular embolization of arteriovenous malformations have all seen transformations in their safety and efficacy, expanding the scope of endovascularly treatable conditions and offering new hope to patients who may have otherwise not been candidates for surgical intervention. Despite this notable progress, challenges persist, including complications associated with device deployment and questions regarding long-term outcomes. This article explores the advancements in endovascular neurosurgical techniques, highlighting the impact on patient care, outcomes, and the evolution of traditional surgical methods.

Cutting Edge Developments in Spine Surgery at the University of Missouri.

The treatment of spinal pathologies has evolved significantly from the times of Hippocrates and Galen to the current era. This evolution has led to the development of cutting-edge technologies to improve surgical techniques and patient outcomes. The University of Missouri Health System is a high-volume, tertiary care academic medical center that serves a large catchment area in central Missouri and beyond. The Department of Neurosurgery has sought to integrate the best available technologies to serve their spine patients. These technological advancements include intra-operative image guidance, robotic spine surgery, minimally invasive techniques, motion preservation surgery, and interdisciplinary care of metastatic disease to the spine. These advances have resulted in safer surgeries with enhanced outcomes at the University of Missouri. This integration of innovation demonstrates our tireless commitment to ensuring excellence in the comprehensive care of a diverse range of patients with complex spinal pathologies.

Advances in Cranial Surgery.

The landscape of the cranial neurosurgery has changed tremendously in past couple of decades. The main frontiers including introduction of neuro-endoscopy, minimally invasive skull base approaches, SRS, laser interstitial thermal therapy and use of tubular retractors have revolutionized the management of intracerebral hemorrhages, deep seated tumors other intracranial pathologies. Introduction of these novel techniques is based on smaller incisions with maximal operative corridors, decreased blood loss, shorter hospital stays, decreased post-operative pain and cosmetically appealing scars that improves patient satisfaction and clinical outcomes. The sophisticated tools like neuroendoscopy have improved light source, and better visualization around the corners. Advanced navigated tools and channel-based retractors help us to target deeply seated lesions with increased precision and minimal disruption of the surrounding neurovascular tissues. Advent of stereotactic radiosurgery has provided us alternative feasible, safe and effective options for treatment of patients who are otherwise not medically stable to undergo complex cranial surgical interventions. This paper review advances in treatment of intracranial pathologies, and how the neurosurgeons and other medical providers at the University of Missouri-Columbia (UMC) are optimizing these treatments for their patients.

Role of Functional neurosurgery in Improving Patient Outcomes in Epilepsy, Movement Disorders, and Chronic Pain.

Functional neurosurgery encompasses surgical procedures geared towards treating movement disorders (such as Parkinson's disease and essential tremor), drug-resistant epilepsy, and various types of pain disorders. It is one of the most rapidly expanding fields within neurosurgery and utilizes both traditional open surgical methods such as open temporal lobectomy for epilepsy as well as neuromodulation-based treatments such as implanting brain or nerve stimulation devices. This review outlines the role functional neurosurgery plays in treatment of epilepsy, movement disorders, and pain, and how it is being implemented at the University of Missouri by the Department of Neurosurgery.

Cerebral Abscess following Mechanical Thrombectomy for Ischemic Stroke: Report of a Case and Review of Literature.

Cerebral infections have been reported after endovascular interventions such as embolization and coiling. Such complications are extremely rare and only one other case has been reported in a patient who underwent an endovascular therapy for ischemic stroke. We report a 32-year-old woman, who presented to our hospital with headaches lasting four weeks after an endovascular intervention for ischemic stroke via mechanical thrombectomy. Further investigations revealed a cerebral abscess in the area of the infarct. She was effectively treated with antibiotics in combination with stereotactic drainage and was discharged after she made a good recovery. A review of literature on cerebral abscesses after minimally invasive procedures such as endovascular intervention was also done and is being presented in this paper. A cerebral abscess can occur rarely after endovascular interventions. A high degree of suspicion is important in identifying patients with an abscess and appropriate treatment can prevent significant morbidity or even death.

Radiographic and clinical outcomes in cavernous carotid fistula with special focus on alternative transvenous access techniques.

Carotid cavernous fistulae (CCF) are dangerous entities that may cause progressive cranial neuropathy, headache and blindness. Endovascular therapy for CCF is the treatment of choice and can be accomplished with minimal morbidity, but optimal treatment strategies vary according to CCF anatomy. We aimed to define a tailored endovascular treatment algorithm for CCF with a focus on traditional and aberrant venous anatomy. Retrospective cohort analysis of data for 57 patients (age range, 18-90 years, mean 53 years) with CCF (35 direct, 22 indirect) was performed. Treatment was transarterial (n=31), transvenous (n=18), combined (n=2), or observation (n=6). Non-conventional transvenous access (that is, via the facial vein, pterygoid plexus, or via direct puncture of the inferior ophthalmic or frontal vein) was employed in five patients. Mean follow-up period was 12 months. Radiographic cure rate in treated CCF was 96%. Forty-five patients presented with ophthalmic symptoms (chemosis, proptosis, eye pain); all resolved within 6 weeks of successful treatment. Forty-three patients presented with cranial nerve III, IV and/or VI palsy; complete recovery was seen in 54% and partial recovery in 18%. Five patients presented with blindness and five with declining visual acuity. No patient with blindness regained sight after treatment, but all five patients with declining vision recovered some visual acuity. The complication rate was 10.6% (one transient abducens nerve palsy, two symptomatic cerebral infarctions, and three groin hematomas). The permanent complication rate was 3.5%. Multimodal treatment of CCF, including non-traditional routes of transvenous access, results in excellent outcomes and low morbidity.

Bypass using V2-V3 segment of the vertebral artery as donor or recipient: technical nuances and results.

OBJECTIVE: Surgical revascularization (bypass) technique has been used to treat vascular diseases of the posterior circulation, including ischemia, aneurysms, and tumors encasing a major artery. We focused on procedures using the V2-V3 segment of the vertebral artery (VA) as either the donor or recipient of the bypass. We have described technical nuances developed over time and evaluated the surgical results of those cases. METHODS: Data on all patients who underwent bypasses using the V2-V3 segment were collected retrospectively from a prospectively maintained database. RESULTS: Twenty patients had bypasses using V2-V3 distal VA as either the donor (13) or recipient (7); 19 patients had an intervening graft and in 1 patient, the VA was used for reimplantation of the posterior inferior cerebellar artery. Except for 1 patient, who died during the perioperative period, the mean follow-up time for the rest of the patients was 24.7 months (range 1-72 months). One patient developed postoperative stroke. One radial artery graft occluded, and a redo saphenous vein graft also occluded in the same patient. All the other bypasses were patent without flow limitation at the latest follow-up. Fourteen patients had a modified Rankin Scale score of 2 or better at the latest follow-up, and 2 died of unrelated causes as the result of their tumors. CONCLUSIONS: The V2-V3 segment of the VA can be used both as a donor and a recipient for bypass surgery. Using the technical steps perfected over time, we are able to achieve surgical results with high rate of graft patency and good functional outcome in patients.

Multimodality treatment of complex unruptured cavernous and paraclinoid aneurysms.

BACKGROUND: Unruptured aneurysms of the cavernous and paraclinoid internal carotid artery can be approached via microsurgical and endovascular approaches. Trends in treatment reflect a steady shift toward endovascular techniques. OBJECTIVE: To analyze our results with multimodal treatment. METHODS: We reviewed patients with unruptured cavernous and paraclinoid internal carotid artery aneurysms proximal to the posterior communicating artery treated at a single center from 2007 to 2012. Treatment included 4 groups: (1) stent-assisted coiling, (2) pipeline endovascular device (PED) flow diverter, (3) clipping, and (4) trapping/bypass. Follow-up was 2 to 60 months. RESULTS: The 109 aneurysms in 102 patients were studied with the following treatment groupings: 41 were done with stent-assisted coiling, 24 with Pipeline endovascular device, 24 by microsurgical clipping, and 20 by trap/bypass. Group: (1) two percent had delayed significant intraparenchymal hemorrhage; (2) thirteen percent had central nerve palsies, 8% had small asymptomatic infarcts, and 4% had small, asymptomatic remote-site hemorrhages; (3) twenty-nine percent of patients suffered from transient central nerve palsies, 4% experienced major stroke, and 8% had small intracerebral hemorrhages; (4) thirty-five percent had transient central nerve palsies, 10% had strokes, and 10% had intracerebral hemorrhages. In terms of follow-up obliteration, 83% had complete/nearly complete obliteration at last follow-up, 17% had residual aneurysms, and 10% required retreatment. Ninety-six percent of group 1 (35/38), 100% of group 2 (23/23), 100% of group 3 (21/21), and 95% of group 4 had modified Rankin Scale scores of 0 to 1. CONCLUSION: Treatment of these aneurysms can be carried out with acceptable rates of morbidity. Careful patient selection is crucial for optimal outcome. Endovascular treatment volumes likely will continue to predominate over microsurgical techniques as changing skill sets evolve in neurosurgery, but individualized application of all available treatment options will continue.

Monitoring flow in extracranial-intracranial bypass grafts using duplex ultrasonography: a single-center experience in 80 grafts over 8 years.

BACKGROUND: High-flow extracranial-intracranial (EC-IC) bypass is performed by using radial artery graphs (RAGs) or saphenous vein grafts (SVGs) for various pathologies such as aneurysms, ischemia, and skull-base tumors. Quantifying the acceptable amount of blood flow to maintain proper cerebral perfusion has not been well established, nor have the variables that influence flow been determined. OBJECTIVE: To identify the normative range of blood flow through extracranial-intracranial RAGs and SVGs as measured by duplex ultrasonography. Multiple variables were evaluated to better understand their influence of graft flow. METHODS: All EC-IC grafts performed at Harborview Medical Center from 2005 to 2012 were retrospectively reviewed for this cohort study. Daily extracranial graft duplex ultrasonography with flow volumes and transcranial graft Doppler were examined, as were short- and long-term outcomes. Both ischemic and hyperemic events were evaluated in further detail. RESULTS: Eighty monitorable high-flow EC-IC bypasses were performed over the 8-year period. Sixty-five bypasses were performed by using RAGs and 15 were performed with SVGs. The average flow was 133 mL/min for RAGs and 160 mL/min for SVGs (P = .25). For both RAG and SVG groups, the donor and recipient vessel selected significantly impacted flow. For the RAG group only, preoperative graft diameter, postoperative hematocrit, and postoperative date significantly influenced flow. A 1-week average of >200 mL/min was 100% sensitive to cerebral hyperemia syndrome. CONCLUSION: This study establishes the normative range of duplex ultrasonographic flow after high-flow EC-IC bypass, as well the usefulness and practicality of such monitoring as a surrogate to flow in the postoperative period.

Cerebral revascularization for difficult skull base tumors: a contemporary series of 18 patients.

OBJECTIVE: Cerebral revascularization has been used in treating difficult skull base tumors when the preservation of the involved native arteries is deemed challenging, and the patients are at risk of developing vascular complications. We aimed to evaluate a recent series of patients who needed high flow cerebral bypasses as part of the surgical treatment strategies for their difficult skull base tumors; to assess current indications and the results of such treatments. METHODS: A prospectively collected consecutive series of patients were studied. These patients received high flow cerebral bypasses in conjunction with surgical resections of the skull base tumors during a 9-year period. RESULTS: A total of 20 high flow bypasses on 18 patients were performed, as part of the treatment plan for skull base tumors. The mean age was 41 years. Four patients had preoperative transient ischemic attack symptoms, three of which had progressed to acute strokes preoperatively. Thirteen patients (72.2%) had gross total resection. There were no acute perioperative stroke or graft occlusions. The mean follow-up was 47 months (2-104 months). One patient developed asymptomatic graft stenosis 8 months after surgery, which was surgically corrected. Fifteen patients had achieved good clinical outcomes (modified Rankin scale, ≤ 2) at the latest follow-up; one patient died postoperatively and two died of their disease. CONCLUSIONS: High flow bypass for cerebral revascularization is a good surgical option for treating certain difficult skull base tumors. High rate of graft patency and low risk of perioperative stroke can be achieved in experienced hands with concurrent high rate of gross total resection of the tumor and good clinical outcome of the patients.

Pediatric bypasses for aneurysms and skull base tumors: short- and long-term outcomes.

OBJECT: Cerebral bypass is a useful microsurgical technique for the treatment of unclippable aneurysms and invasive skull base tumors. The authors present the largest reported series of cerebrovascular bypasses in the pediatric population. They describe the short- and long-term clinical and radiographic outcomes of extracranial-intracranial and local bypasses performed for complex cerebral aneurysms and recurrent, invasive, and malignant skull base tumors in pediatric patients. METHODS: A consecutive series of 17 pediatric patients who underwent revascularization were analyzed retrospectively for indications, graft patency, and neurological outcomes. RESULTS: The mean age was 12 years (median 11 years, range 4-17 years), and there were 7 boys (41%) and 10 girls (59%). A total of 18 bypasses were performed in 17 patients and included 10 aneurysm cases (55.5%) and 8 tumor cases (45%). Of these 18 bypasses, there were 11 (61.1%) extracranial-intracranial bypasses (10 saphenous vein grafts [90%] and 1 radial artery graft [10%]), 1 side-to-side anastomosis (5.5%), 2 intracranial reimplants (11.1%), and 4 interposition bypass grafts (22.2%; 2 radial artery grafts, 1 saphenous vein graft, and 1 lingual artery graft). The mean clinical follow-up was 40.5 months (median 24 months, range 3-197 months). The mean radiographic follow-up was 40 months (median 15 months, range 9-197 months). Eighty-two percent of patients (14 of 17) achieved a modified Rankin Scale score between 0 and 2; however, 2 patients died of disease progression during long-term follow-up. The short-term (0- to 3-month) graft patency rate was 100%. Two patients had graft stenosis (11.7%) and underwent graft revisions. Two patients (11.1%) with giant middle cerebral artery aneurysms (> 25 mm) had strokes postoperatively but recovered without a persistent neurological deficit. One patient observed for 197 months showed a stable dysplastic change at the end of the graft. The long-term graft patency was 100% with a mean follow-up of 40 months. There were 2 deaths in the cohort during follow-up; both patients died of malignant tumors (osteogenic sarcoma and chondrosarcoma). CONCLUSIONS: The authors conclude that in properly selected cases, bypasses can be safely performed in patients with aneurysms and skull base tumors. The bypasses remained patent over long periods of time despite the growth of the patients.

Flow diversion radial artery bypass graft coupled with terminal basilar artery occlusion for the treatment of complex basilar apex aneurysms: operative nuances.

BACKGROUND: A subset of basilar apex aneurysms are unsuitable for either primary microsurgical clipping or endovascular coiling. These complex aneurysms can be treated by terminal basilar artery occlusion, but only if collateral circulation is adequate. To circumvent these complications, a high-flow vertebral artery-posterior cerebral artery or middle cerebral artery-posterior cerebral artery bypass may be performed to create an adequate collateral circulation to allow treatment of the aneurysm by basilar artery occlusion and/or clipping. OBJECTIVE: To discuss the operative nuances of this approach in the case of a 47-year-old man with progressive hemiparesis resulting from brainstem compression from a giant, unruptured basilar apex aneurysm with absent posterior communicating artery collaterals and incorporation of bilateral superior cerebellar arteries and posterior cerebral arteries within the aneurysm neck. METHODS: The patient underwent a staged bypass from V3 to P2 coupled with terminal basilar artery occlusion. RESULTS: The patient initially presented as modified Rankin Scale score 2 with right hemiparesis. The aneurysm ruptured after the first stage of the operation, and the patient underwent a V3 to P2 bypass the next day. His postprocedural neurologic decline improved at the 14-month follow-up to modified Rankin Scale score 2, with substantial reduction in aneurysm size observed at 9 months. The outcomes for 3 other bypass cases for basilar apex aneurysms are also summarized. CONCLUSION: : We discuss the indications, preoperative diagnostic workup, operative management, and postoperative outcomes in managing challenging basilar apex aneurysms. In our experience, high-flow bypass procedures with or without hunterian ligation in the treatment of these aneurysms are well tolerated with good long-term results.

Basilar tip aneurysms: a microsurgical and endovascular contemporary series of 100 patients.

BACKGROUND: Endovascular therapy has largely replaced microsurgical clipping for the treatment of basilar tip aneurysms. OBJECTIVE: We describe the variables our center evaluates when choosing to clip or coil basilar tip aneurysms and our outcomes. Four case illustrations are presented. METHODS: All patients with ruptured or unruptured basilar tip aneurysms from 2005 to April 2012 were examined. The patients were treated by 2 interventional neuroradiologists and 2 dually trained neurosurgeons. RESULTS: There were 63 ruptured (clipped 38%, coiled 62%) and 37 unruptured (clipped 35%, coiled 65%) aneurysms in this 100-patient study. Seventy percent of the patients with ruptured aneurysms and 92% of the patients with unruptured aneurysms had a good outcome (modified Rankin scale 0-2) at 3 months. For ruptured aneurysms, there was a statistically significant difference in clipping and coiling with respect to age and treatment modality (clip 48.8 years, coil 57.6 years). Patients in the coiled group had higher dome-to-neck (1.3 vs 1.1) (P = .01) and aspect ratios (1.6 vs 1.2) (P = .007). In the ruptured coiling group, 69.5% achieved a Raymond 1 radiographic outcome, 28% Raymond 2, and 2.5% Raymond 3. Eleven (17.4%) patients required re-treatment, and 3 (4.4%) patients were re-treated more than twice. Coiling of unruptured aneurysms resulted in 75% Raymond 1. There were no residual lesions for unruptured clipped aneurysms. There were no differences in outcome between clipping and coiling in the ruptured and unruptured group. CONCLUSION: In our current management of basilar tip aneurysms, the majority can be treated via endovascular means, albeit with the expectation of a higher percentage of residual lesions and recurrences. Microsurgery is still appropriate for aneurysms with complex neck morphologies and in young patients desiring a more durable treatment.