In vivo cerebral aneurysm models.

Cerebral aneurysm rupture is a devastating event resulting in subarachnoid hemorrhage and is associated with significant morbidity and death. Up to 50% of individuals do not survive aneurysm rupture, with the majority of survivors suffering some degree of neurological deficit. Therefore, prior to aneurysm rupture, a large number of diagnosed patients are treated either microsurgically via clipping or endovascularly to prevent aneurysm filling. With the advancement of endovascular surgical techniques and devices, endovascular treatment of cerebral aneurysms is becoming the first-line therapy at many hospitals. Despite this fact, a large number of endovascularly treated patients will have aneurysm recanalization and progression and will require retreatment. The lack of approved pharmacological interventions for cerebral aneurysms and the need for retreatment have led to a growing interest in understanding the molecular, cellular, and physiological determinants of cerebral aneurysm pathogenesis, maturation, and rupture. To this end, the use of animal cerebral aneurysm models has contributed significantly to our current understanding of cerebral aneurysm biology and to the development of and training in endovascular devices. This review summarizes the small and large animal models of cerebral aneurysm that are being used to explore the pathophysiology of cerebral aneurysms, as well as the development of novel endovascular devices for aneurysm treatment.

Long-Term Outcomes of Mechanical Thrombectomy for Stroke: A Meta-Analysis.

Mechanical thrombectomy (MT) has become the standard treatment for large vessel occlusion (LVO) in acute ischemic stroke (AIS). Few studies have investigated long-term outcomes for AIS treated with MT. Therefore, a pooled meta-analysis using data from randomized clinical trials (RCT) was performed to assess for long-term clinical outcomes. A systematic literature search was conducted on 27 September 2017, by searching the English literature in the Cochrane Library, MEDLINE, and Embase for RCTs investigating long-term outcomes (greater than standard 3-month timepoint) of endovascular intervention versus medical management for patients with AIS. The study was carried out according to PRISMA guidelines and random effects analysis was carried out to account for heterogeneity. Three trials were included: IMS III, MR CLEAN, and REVASCAT, comprising a total of 1,362 patients. Long-term clinical outcomes were available for 1-year follow-up in IMS III and REVASCAT and at 2 years in MR CLEAN. Functional independence at long-term follow-up favored endovascular stroke intervention (OR 1.51; p = 0.02). When stratified by LVO inclusion criteria, greater endovascular functional independence benefits were observed (OR 1.85; p = 0.0005). There was a significant difference between the 2 arms in favor of endovascular therapy for the quality of life at long-term follow-up (mean difference 0.11; p = 0.0002). No difference in mortality at long-term follow-up was observed (OR 0.82; p = 0.12). We conclude that endovascular therapy results in favorable outcomes at long-term follow-up for patients with acute ischemic stroke compared to standard medical treatment alone and that the 90-day timepoint offers a fair representation of the long-term outcomes.

Transradial approach for mechanical thrombectomy in anterior circulation large-vessel occlusion.

OBJECTIVE The goals of this study were to describe the authors' recent institutional experience with the transradial approach to anterior circulation large-vessel occlusions (LVOs) in acute ischemic stroke patients and to report its technical feasibility. METHODS The authors reviewed their institutional database to identify patients who underwent mechanical thrombectomy via a transradial approach over the 2 previous years, encompassing their experience using modern techniques including stent retrievers. RESULTS Eleven patients were identified. In 8 (72%) of these patients the right radial artery was chosen as the primary access site. In the remaining patients, transfemoral access was initially attempted. Revascularization (modified Treatment in Cerebral Ischemia [mTICI] score ≥ 2b) was achieved in 10 (91%) of 11 cases. The average time to first pass with the stent retriever was 64 minutes. No access-related complications occurred. CONCLUSIONS Transradial access for mechanical thrombectomy in anterior circulation LVOs is safe and feasible. Further comparative studies are needed to determine criteria for selecting the transradial approach in this setting.

Bilateral cerebral infarction in the setting of pituitary apoplexy: a case presentation and literature review.

BACKGROUND: Pituitary tumor apoplexy (PTA) is a potentially fatal condition caused by hemorrhage and rapid expansion of a pituitary tumor. One rare consequence of PTA is occlusion of the intracavernous carotid arteries, very rarely leading to cerebral infarction. PURPOSE: To describe a case of PTA leading to bilateral cerebral infarction and provide an extensive literature review of all previously reported cases of PTA leading to cerebral infarction. We discuss how these cases contribute to our understanding of the management of PTA, and we also discuss the differences between cases associated with the reported mechanism of carotid occlusion (compression vs. vasospasm). CASE PRESENTATION: A 56-year-old previously healthy woman complained of severe headache and visual loss one day after sustaining a fall from standing. Computed tomography demonstrated an enlarged sellar and suprasellar mass displacing both cavernous ICAs laterally, with multiple bilateral hypodense areas in the ICA distribution consistent with infarction. She clinically deteriorated and underwent endoscopic transsphenoidal gross total resection for suspected PTA within 48 hours after falling. Her prognosis remained poor after 5 days, and support was withdrawn. CONCLUSION: Twenty-four cases of PTA leading to cerebral infarction have been previously documented-four bilateral, our case being the fifth. Based on our review, the presence of infarction itself does not seem to warrant surgical management in the absence of previously established indications for surgery (such as a deteriorating visual field), despite a 3-5 times mortality increase. No conclusion regarding the role of the mechanism of occlusion can be made at this time.

The role of magnetic resonance-guided laser ablation in neurooncology.

INTRODUCTION: The use of magnetic resonance-guided laser-induced thermal therapy (MR-LITT) as a minimally invasive method of treating intra-cranial pathology is a rapidly growing field. The use of MR-LITT in neurooncology has shown promising results; however, there has been no review to date of the current literature. METHODS: A review of the published literature regarding MR-LITT in neurooncology was performed. Studies on PubMed were included if at least one patient with a cerebral tumour or radiation necrosis was treated using quantitative MR thermography-guided LITT, as well as if either safety or outcomes were discussed. RESULTS: In treating recurrent Grade-III and -IV gliomas, we found improved median overall survival of 20.9 months from diagnosis of recurrence, which is comparable with that of 18.9 months for high-dose-rate brachytherapy and 24.4 months for repeated open surgery. Median progression-free survival (PFS) of recurrent glioma is noted to be 4.5 months. For metastatic lesions, we found a median overall survival (OS) to vary between 9.0 and 19.8 months with a PFS between 3.8 and 8.5 months. Current literature reports median OS in similar patients to lie between 7.0 and 28.6 months. Severe complication rates (with permanent deficits) are found to be between 12 and 16.7%, comparable with 11% found in literature for open surgery. CONCLUSIONS: The current literature shows that MR-LITT is safe and shows promising local tumour control rates. Larger randomised studies are warranted to further investigate this adjuvant therapy in the treatment of recurrent high-grade gliomas and metastases.

Predictors of long-term survival in patients with glioblastoma multiforme: advancements from the last quarter century.

Over the last quarter century there has been significant progress toward identifying certain characteristics and patterns in GBM patients to predict survival times and outcomes. We sought to identify clinical predictors of survival in GBM patients from the past 24 years. We examined patient survival related to tumor locations, surgical treatment, postoperative course, radiotherapy, chemotherapy, patient age, GBM recurrence, imaging characteristics, serum, and molecular markers. We present predictors that may increase, decrease, or play no significant role in determining a GBM patient's long-term survival or affect the quality of life.

Discriminating radiation necrosis from tumor progression in gliomas: a systematic review what is the best imaging modality?

Differentiating post radiation necrosis from progression of glioma and pseudoprogression poses a diagnostic conundrum for many clinicians. As radiation therapy and temozolomide chemotherapy have become the mainstay of treatment for higher-grade gliomas, radiation necrosis and post treatment changes such as pseudoprogression have become a more relevant clinical problem for neurosurgeons and neurooncologists. Due to their radiological similarity to tumor progression, accurate recognition of these findings remains paramount given their vastly different treatment regimens and prognoses. However, no consensus has been reached on the optimal technique to discriminate between these two lesions. In order to clarify the types of imaging modalities for recurrent enhancing lesions, we conducted a systematic review of case reports, case series, and prospective studies to increase our current understanding of the imaging options for these common lesions and their efficacy. In particular, we were interested in distinguishing radiation necrosis from true tumor progression. A PubMed search was performed to include all relevant studies where the imaging was used to differentiate between radiation necrosis and recurrent gliomas with post-radiation enhancing lesions. After screening for certain parameters in our study, seventeen articles with 435 patients were included in our analysis including 10 retrospective and 7 prospective studies. The average time from the end of radiation therapy to the onset of a recurrent enhancing lesion was 13.2 months. The most sensitive and specific imaging modality was SPECT with a sensitivity of 87.6 % and specificity of 97.8 %. Based on our review, we conclude that certain imaging modalities may be preferred over other less sensitive/specific techniques. Overall, tests such as SPECT may be preferable in differentiating TP (tumor progression) from RN (radiation necrosis) due to its high specificity, while nonspecific imaging such as conventional MRI is not ideal.

Intracranial Angioplasty via Type II Proatlantal Intersegmental Artery.

A proatlantal intersegmental artery (PIA) is an exceedingly rare primitive anastomosis between the carotid and vertebrobasilar circulations. PIAs may be accompanied by ipsilateral or bilateral vertebral artery (VA) agenesis and can originate from the cervical internal carotid artery (ICA, type I) or external carotid artery (ECA, type II) before eventually joining the vertebrobasilar system. Several authors have described this anomaly in different clinical scenarios, but to our knowledge, there are no studies documenting VA angioplasty through a type II PIA in the setting of vertebrobasilar stroke. We present the case of vertebrobasilar stroke in which the right VA did not originate from the right subclavian artery but instead from the ECA. The patient was subsequently determined to have a type II PIA. We performed right VA angioplasty via the PIA, followed by partial restoration of vertebrobasilar blood flow. This is the first documented case of intracranial vertebral angioplasty through a type II PIA and serves as a reminder for neuroendovascular surgeons about persistent fetal circulation. In such instances, an angiogram of both the ICA and ECA should be performed to exclude right VA stenosis and visualize persistent fetal circulation. This case underscores the complexity of arterial thrombotic events, the beneficial role of endovascular intervention, and the necessity of future studies to identify the optimal treatment methods for vertebrobasilar stroke.

Combined Transradial and Upper Extremity Transvenous Accesses in the Treatment of Carotid-Cavernous Fistulae: Two Case Reports and a Literature Review.

The expansion of indications for neurointerventional procedures, combined with the need to treat a diverse patient population, has driven a need for broader access options. Concurrent arterial and venous access is often necessary for the diagnosis and treatment of various neurovascular diseases. Although complication rates are low, life-threatening severe complications have been reported with these access methods. Moreover, venous access through traditional routes can be challenging in patients with large body habitus. There is a growing trend of utilizing radial artery access for neuroendovascular procedures due to the increased ease of access and similar efficacy. Nevertheless, the use of upper limb veins in neurointerventional procedures is still rare. Upper extremity transvenous access (UETV) has recently emerged as an alternative strategy for neurointerventionalists, but data are limited. This study reports two cases of successful combined upper extremity transvenous access (TVA) and transradial access (TRA) in the treatment of carotid artery-cavernous fistulae. Combined TRA and UETV is a feasible, promising access strategy for patients and may also confer the same safety and patient satisfaction outcomes that have been seen with TRA. Further studies are needed to elucidate the exact impact this strategy has on patient outcomes and satisfaction.

Transbrachial Access Site Complications in Endovascular Interventions: A Systematic Review of the Literature.

The transfemoral approach (TFA) or transradial approach (TRA) serves as the primary technique for most endovascular cases; however, the transbrachial (TBA) route is an alternative access site used when TFA and TRA are contraindicated. Although TBA has advantages over TRA, such as the ability to accommodate large guide catheters and devices, there is some apprehension in implementing TBA due to perceived access site complication rates. This article aims to glean the rate of access site complication from current literature. Relevant studies were identified using the following search terms: ((access site complications) AND ((endovascular AND brachial) OR (percutaneous brachial access) OR (brachial))) OR (endovascular AND (percutaneous brachial access)); endovascular + brachial artery; endovascular + brachial artery + access site; and endovascular + brachial artery + access site complications. Articles published after 2008 addressing major complication rates from percutaneous TBA interventions were included. Fifteen studies out of 992 total articles met the inclusion criteria. The major access site complication rate was 75/1,424 (5.27%). Patients who underwent hemostasis with a vascular closure device (VCD) had a major complication rate of 13/309 (4.21%) compared to a major complication rate of 65/1122 (5.79%) for patients who underwent hemostasis with manual compression (MC). The major access site complication rate associated with TBA was 5.27%, which is relatively high compared to the complication rate in TFA or TRA. More prospective trials are needed to fully understand the access site complication rate in TBA interventions.

Acute subdural hematoma due to acute myeloid leukemia and B-cell lymphoma.

Chloroma, is an rare malignant tumor characterized by the extramedullary blast proliferation of myeloid lineages that subsequently change the normal architecture of surrounding tissues. Because this is very rare disease, primary central nervous system myeloid sarcoma has not been widely reported. Myeloid sarcoma, as a group of heterogenetic diseases, presents with differential clinical and histological pictures depending upon the primary affected site. We are presenting a 77-year-old gentleman, with past medical history of chronic lymphoblastic leukemia that was not on any treatment and who presented with complaints of lethargy, disorientation, and weakness. CT scan of the head showed left-sided subdural hematoma with significant mass effect with left-to-right shift. Craniotomy and hematoma evacuation was performed and hematoma and subdural lesion was sent for pathological evaluation. Histologic examination of the hematoma revealed solid sheets of small-medium sized atypical hematopoietic cells that was imbedded in an acute and chronic hematoma. To confirm the final diagnosis, flow cytometry was performed and showed two neoplastic clones, consistent with acute myeloid leukemia with monocytic differentiation and a separate mature B-cell lymphoma. To our knowledge we are presenting the first case in the literature of the Intracranial acute myeloid leukemia/myeloid sarcoma and B-cell lymphoma that was found in the same brain lesion.

Recurrent Cardioembolic Strokes Due to Marantic Endocarditis As the Initial Presentation of Colorectal Adenocarcinoma.

Metastases to the brain from primary colorectal carcinoma are rare. Existing literature describing cranial nerve palsy from metastatic colorectal cancer is scattered. To our knowledge, we are the first to describe the combination of CN deficits V, VII, and XII as the initial presentation of colorectal malignancy. The authors present the case of a patient with no past medical history who presented with multiple cranial nerve deficits of the right trigeminal, facial, and hypoglossal nerves. MRI of the brain revealed a mass in Meckel's cave, which explained the involvement of the trigeminal nerve (CN V) but not the facial (CN VII) and hypoglossal (CN XII) nerves. Further workup revealed multiple cardioembolic strokes caused by nonbacterial thrombotic endocarditis (NBTE). Extensive workup for the cause of his NBTE and subsequent cerebrovascular events revealed colorectal adenocarcinoma.

Ruptured Intracranial Aneurysm Presenting as Isolated Acute Subdural Hemorrhage.

Ruptured intracranial aneurysms are often associated with serious neurologic sequelae, often as a result of subarachnoid or intraparenchymal hemorrhage. Less commonly, ruptured intracranial aneurysms can lead to subdural hemorrhage. However, the characteristic clinical presentation and optimal treatment of associated subdural hemorrhage are unclear due to the paucity of such cases that exist in the current literature. Affected patients may complain of nonspecific symptoms such as headaches, nausea, and confusion. Because of the severity of the disease, rapid diagnosis and intervention is required to lower the high morbidity and mortality rates. Commonly used treatment options include endovascular coiling and microsurgical clipping. Neuroendovascular surgery is often preferred, especially in aneurysms not amenable to surgical clipping, in poor surgical candidates, and cases with endovascularly favorable anatomy. The authors present the case of a patient who came to the hospital with ischemic stroke-like symptoms and was found to have a ruptured posterior communicating artery (PCoA) aneurysm and associated acute subdural hematoma (SDH) without obvious subarachnoid hemorrhage (SAH). Endovascular coiling of the aneurysm was performed successfully the following craniotomy for SDH evacuation, and the patient was discharged to a rehabilitation facility.

Surgical Treatment of Dural Arteriovenous Fistula: A Case Report and Literature Review.

Dural arteriovenous fistulas (dAVF) are rare, acquired intracranial arteriovenous malformations consisting of a pathological shunt located within the intracranial dura matter. The etiology of dAVFs remains unclear, but current thought suggests that these lesions are associated with thrombosis of the dural sinuses and other intracranial veins. dAVF's with severe symptomatology or high-risk angioarchitecture should be treated without delay, and endovascular repair is generally accepted as the first-line treatment. Both transarterial and transvenous approaches can be used to cure dAVFs. Surgery and stereotactic radiosurgery may also be used when endovascular approaches are unsuccessful or not feasible. Some studies, however, have shown that surgery for dAVFs in the anterior cranial fossa is preferred over the endovascular approach. Due to the proximity of some dAVFs to the orbit, endovascular embolization of the dAVF carries a higher risk of complications, primarily due to the formation of dangerous extracranial or intracranial anastomoses. We present the case of a 64-year-old male with an incidentally discovered Borden type III dAVF arising from the anterior branches of the middle meningeal artery and draining into the middle cerebral vein. Due to the location of his dAVF, craniotomy was selected for ligation of the fistula. The procedure went without complication. A catheter angiogram of the brain one month after surgery showed an absence of flow through the arteriovenous fistula and a middle meningeal artery that had returned to its normal caliber.

Five-Level Anterior Cervical Discectomy And Fusion.

Anterior cervical discectomy and fusion (ACDF) is a common treatment modality that has shown good clinical results in patients with cervical degenerative disc disease. ACDF remains the procedure of choice for most patients given its satisfactory clinical outcomes and proven radiological fusion ranging from 90-100%. Five-level ACDF is a very rare type of surgery, even in large spine centers. This type of procedure is unique because, beyond three or four levels, the surgeon needs to switch from a transverse incision to a longitudinal incision along the medial sternocleidomastoid (SCM) muscle border, which is less preferred for cosmetic reasons. Another reason why this procedure is seldom performed is that extreme multilevel ACDF is associated with higher complication and failure rates. Literature covers one, two, and three-level anterior surgeries, but there are few studies reporting the outcomes of five-level ACDF. In the few studies that do report five-level ACDF, the data is controversial. Some studies show the risk of adjacent-segment disease increasing with a higher number of fused levels and increasing incidences of reoperation. Other studies show no changes in the risk of adjacent segment disease in multilevel ACDF in comparison with single-level ACDF. One study even showed a decreased level of adjacent-segment disease and reoperation rates in multilevel ACDF when compared to single-level ACDF. To contribute to current knowledge, we share our experience with five-level ACDF. We report the case of a 63-year-old female who presented with complaints of progressively worsening weakness in the upper extremities. MRI of her cervical spine demonstrated multilevel degenerative disc disease throughout C3-T1 with reversal of normal lordosis and a kyphotic deformity. We performed a successful ACDF at C3-T1 as well as partial corpectomy of the C5 and C6 vertebrae. We did it through a standard transverse incision from the midline to the medial border of the SCM within a preexisting neck crease, demonstrating that in select patients, extreme multilevel ACDF can be performed with proper anatomical dissection and without the need for multiple or longitudinal incisions.

Low Anterior Cervical Approach Without Sternotomy or Clavicle Resection for Upper Thoracic Vertebra Corpectomy.

The spine is the third most common site for metastatic disease following the lung and the liver. Approximately 60-70% of patients with metastatic cancer will have metastasis to the spine, but only 10% of these will be symptomatic. Metastases to the spine may involve the bone, epidural space, or the spinal cord. While chemotherapy and radiation therapy are the primary treatments for metastatic disease, spinal cord compression is an indication for surgical intervention. For vertebral body lesions, anterior vertebral reconstruction and stabilization also have the advantage of providing immediate stability to the vertebral column, but this anterior surgical approach to the upper thoracic spine is fraught with complications. The approach typically involves some combination of thoracotomy, sternotomy, or clavicle resection with anterior dissection into the superior mediastinum. To avoid unnecessary sternotomy and its associated complications, surgical access without sternotomy can be performed in certain cases. A sagittal MRI scan of the spine can be used to evaluate the level of the sternal notch in relation to the upper thoracic spine. If a tangential line can be drawn superior to the sternal notch and inferior to the level of the involved vertebra, surgical access without sternotomy can be performed. We present a case of a 52-year-old female with metastases to the upper thoracic vertebrae who underwent successful T2 corpectomy and T1-3 anterior fusion via a low anterior cervical approach, without sternotomy or clavicle resection.

The Use of BrainPath Tubular Retractors in the Management of Deep Brain Lesions: A Review of Current Studies.

BACKGROUND: Traditional retraction to access deep intraparenchymal brain lesions results in vascular disruption. Tubular retractors such as the BrainPath tubular retractor system were developed to reduce retractor-related force injuries via radial dispersion of force. Our study seeks to assess the indications, benefits, and complications associated with BrainPath retractors. METHODS: A literature search of PubMed MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Cochrane Database of Systematic Reviews was performed. The search terminology used was "BrainPath OR Brain-Path." The BrainPath Web site was also examined. Postoperative morbidity and mortality were analyzed to estimate complications linked to using the retractor. RESULTS: Twenty-nine articles (n = 289 patients) met the inclusion criteria. BrainPath was used primarily for tumor resections and hematoma evacuations. These cases were subdivided into groups based on lesion location, size, and resection volume for further analysis. Gross total resection was achieved in 79% of tumor excisions and subtotal resection in 21%. Hematoma evacuation >90% of original hematoma volume was achieved in 65.1% of cases, 75%-90% of original volume in 21.7%, and <75% in the remaining 13.2%. The complication rate attributed to retractor use was 8.3%. CONCLUSIONS: This report is the first formal assessment of the BrainPath tubular retraction system, highlighting technical considerations of the retractor from the surgeon's perspective, patient outcomes, and complications. The retractor is a safe, efficacious system that can be used for tumor resection or biopsy and hematoma evacuation. However, further randomized controlled trials are indicated to accurately assess complication rates and outcomes.

Treatment of Bilateral Giant Fusiform Petrocavernous Aneurysms.

Aneurysms of the petrous segment of the internal carotid artery (ICA) are exceedingly rare. They are thought to arise from traumatic, mycotic, or congenital etiologies. We present a case of bilateral giant fusiform aneurysms of the petrocavernous ICA treated with bilateral flow-diverting stent placement. An 18-year-old male presented to our institution with headaches, nausea, vomiting and blurry vision that had been present since the day prior. Visual exam revealed decreased visual acuity bilaterally and a temporal field cut superiorly and inferiorly of the left eye. CT and MR imaging revealed bilateral lesions of the petrous segment of the ICA bilaterally. Catheter angiography demonstrated bilateral giant fusiform aneurysm of the petrocavernous ICA. The patient was treated with aspirin 325 mg and clopidogrel 75 mg orally daily for one week prior to the exam. VerifyNow (Accriva; San Diego, CA) confirmed adequate platelet inhibition. The right ICA was treated first, with a multiple flow-diverting stent construct. No complications were noted and the patient was discharged to home two days later. He was brought back three weeks later, and the left ICA was treated with a multiple flow-diverting stent construct. Again, no complications were noted and the patient was discharged uneventfully. The patient returned for his six-month follow-up angiogram with improvement of his visual acuity and resolution of headaches. However, the patient had ceased taking both anti-platelet medications six weeks prior. Angiography revealed no filling of the aneurysm in the right ICA, however, the left ICA was occluded at the origin. The patient was resumed on daily aspirin 325 mg orally and will have follow-up catheter angiography at 12 months. Petrous segment ICA aneurysms are rare. Most are thought to arise from trauma, infection, or congenital etiologies. These aneurysms are typically fusiform in nature, and can extend into the cavernous segment of the ICA. The natural history of these aneurysms is not well understood given their rarity. Current literature advocates for asymptomatic patients to be treated conservatively given that the natural history is not well known. Treatment is recommended in symptomatic patients, who may present with symptoms of local mass effect or ischemic stroke due to emboli. Endovascular options include flow diverting stent or covered stent placement, coil embolization with or without stent-assistance, or ICA occlusion. Open surgical options include trapping and high-flow bypass. When bilateral lesions are present, the management algorithm must be amended. We elected to treat the asymptomatic side first (right ICA), due to the presence of a significant kink within the aneurysm on the left. Once the right side was treated successfully, the symptomatic side was treated with a multiple stent construct. The patient's six-month angiogram demonstrated occlusion of the left ICA, likely due to non-compliance with antiplatelet medications. This further reiterates the need for dual-antiplatelet therapy and patient education and compliance with flow diverting stents. We report a rare case of bilateral giant fusiform petrocavernous aneurysms treated with bilateral Pipeline embolization devices in multiple device construct, demonstrating the feasibility and safety of this treatment option for this pathology.

Intracranial Tubular Retractor Systems: A Comparison and Review of the Literature of the BrainPath, Vycor, and METRx Tubular Retractors in the Management of Deep Brain Lesions.

In neurosurgery, parenchymal injury resulting from focal exertion of pressure on retracted tissue is a common complication associated with the use of plate and self-sustaining retractors to access deep intraparenchymal lesions. Tubular retractors, including Vycor, BrainPath, and METRx, were developed to reduce retraction injuries via radial dispersion of force. Our study seeks to compare these retraction systems and assess their respective indications, benefits, and associated complications. A systematic review of PubMed MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, and Cochrane Database of Systematic Reviews was performed. Twenty-nine articles (n = 289 patients) for BrainPath, 12 articles (n = 106 patients) for Vycor, and 3 articles for METRx (n = 31 patients) met the inclusion criteria. This report is the first formal comparison of the BrainPath, Vycor, and METRx tubular retraction systems. We found that all 3 retractors were effective in accessing intraparenchymal lesions. Although we found that the retractor systems were used more commonly in different locations and for different diseases, there was no significant difference in complications or mortality among the 3 retractors.

Use of Vycor Tubular Retractors in the Management of Deep Brain Lesions: A Review of Current Studies.

BACKGROUND: Traditional manual retraction to access deep-seated brain lesions has been associated with complications related to vascular compromise of cerebral tissue. Various techniques have been developed over time to minimize injury, such as self-sustaining retractors, neuronavigation, and endoscopic approaches. Recently, tubular retractors, such as the ViewSite Brain Access System (VBAS), have been developed to reduce mechanical damage from retraction by dispersing the force of the retractor radially over the parenchyma. Therefore, we sought to review the current literature to accurately assess the indications, benefits, and complications associated with use of VBAS retractors. METHODS: A literature search for English articles published between 2005 and 2019 was performed using the MEDLINE database archive with the search terminology "Vycor OR ViewSite OR Brain-Access-System NOT glass." The VBAS website was also examined. Only articles detailing neurosurgical procedures using the VBAS tubular retractor system alone, or in combination with other retractors, were included. Postoperative morbidity and mortality were analyzed to estimate complications linked to using the retractor. RESULTS: Twelve publications (106 patients) met the inclusion criteria. The VBAS retractor was used for tumor resections, hematoma evacuations, cyst removal, foreign body extractions, and lesion resection in toxoplasmosis and multiple sclerosis. These cases were subdivided into groups based on lesion location, size, and resection volume for further analysis. Gross total resection was achieved in 63% of tumor excisions, and subtotal resection was achieved in 37%. Hematoma evacuation was successful in all cases. There were 3 short-term postoperative complications linked to the retractor, with an overall complication rate of 2.8%. CONCLUSIONS: This report is the first formal assessment of the VBAS, highlighting technical considerations of the retractor from the surgeon's perspective, patient outcomes, and complications. The retractor is a safe and efficacious tubular retraction system that can be used for tumor biopsy and resection, colloid cyst removal, hematoma evacuation, and removal of foreign bodies. However, further randomized controlled trials are indicated to accurately assess complication rates and outcomes.