Stereotactic radiosurgery for intracranial dural arteriovenous fistulas: patient outcomes and lessons learned over a 3-decade single-center experience.

OBJECTIVE: The role of stereotactic radiosurgery (SRS) in the management of intracranial dural arteriovenous fistula (dAVF) is unclear given the rarity of this lesion and the variability in treatment paradigms. This study describes a 3-decade experience with the SRS technique and its outcomes for patients with dAVF. METHODS: The authors conducted a retrospective analysis of patients with dAVF who had undergone single-fraction SRS in the period from 1990 to 2021. The imaging modality initially used for targeting was angiography alone, then angiography plus MRI, and most recently MRI alone. RESULTS: Two hundred twenty-two patients underwent SRS alone (n = 56, 25%) or SRS plus embolization (n = 166, 75%), depending on the severity of symptoms or the presence of cortical venous drainage (CVD). Most patients were women (64%), and the median patient age was 60 years. Common presenting symptoms were pulsatile bruit (55%), visual change or chemosis (21%), headache (10%), and intracerebral hemorrhage (5%). The most frequent dAVF location was the transverse or sigmoid sinus (44%), followed by the cavernous sinus (24%), jugular bulb (9%), and torcula (5%). CVD was noted in 28% of cases, and venous ectasia in 5%. Borden dAVF types among the patients were I (72%), II (20%), and III (8%). Cognard dAVF types among the patients were I (44%), IIa (27%), IIb (5%), IIa+b (15%), III (4%), and IV (5%). The median SRS treatment volume was 7.6 cm3; the median margin and maximum doses were 18 and 36 Gy, respectively. Follow-up after SRS was available for 209 patients (median follow-up 31 months). Obliteration was noted in 75% of the patients (110/147) with follow-up vascular imaging; the median time to obliteration was 37 months. Multivariate analysis revealed that a cavernous sinus dAVF location was predictive of radiological obliteration (HR 1.86, 95% CI 1.08-3.18, p = 0.024). The absence of CVD was predictive of obliteration in subgroup analysis of non-cavernous sinus dAVF (HR 0.53, 95% CI 0.29-0.98, p = 0.04). Symptoms resolved in 86% of patients (160/185) with clinical follow-up. Twelve patients (5.4%) had complications related to angiography for SRS planning (n = 2, 0.9%), embolization (n = 3, 1.4%), post-SRS hemorrhage (n = 1, 0.5%), delayed sinus thrombosis (n = 1, 0.5%), radiation-induced tumors (n = 2, 0.9%), and chronic encapsulated expanding hematoma (n = 3, 1.4%). CONCLUSIONS: SRS alone or in conjunction with embolization provided obliteration and symptom relief for the majority of patients with dAVF, with a low rate of procedure-related morbidity. Patients are at risk for late radiation-related complications, which can require treatment many years after SRS.

Impact of duration of dual anti-platelet therapy on risk of complications after stent-assisted coiling of unruptured aneurysms.

BACKGROUND: The optimal duration for dual antiplatelet therapy (DAPT) after stent-assisted coiling (SAC) of intracranial aneurysms is unclear. Longer-term therapy may reduce thrombotic complications but increase the risk of bleeding complications. METHODS: A retrospective review of prospectively maintained data at 12 institutions was conducted on patients with unruptured intracranial aneurysms who underwent SAC between January 1, 2016 and December 31, 2020, and were followed ≥6 months postprocedure. The type and duration of DAPT, stent(s) used, outcome, length of follow-up, complication rates, and incidence of significant in-stent stenosis (ISS) were collected. RESULTS: Of 556 patients reviewed, 450 met all inclusion criteria. Nine patients treated with DAPT <29 days after SAC and 11 treated for 43-89 days were excluded from the final analysis as none completed their prescribed duration of treatment. Eighty patients received short-term DAPT. There were no significant differences in the rate of thrombotic complications during predefined periods of risk in the short, medium, or long-term treatment groups (1/80, 1.3%; 2/188, 1.1%; and 0/162, 0%, respectively). Similarly, no differences were found in the rate of hemorrhagic complications during period of risk in any group (0/80, 0%; 3/188, 1.6%; and 1/162, 0.6%, respectively). Longer duration DAPT did not reduce ISS risk in any group. CONCLUSIONS: Continuing DAPT >42 days after SAC did not reduce the risk of thrombotic complications or in-stent stenosis, although the risk of additional hemorrhagic complications remained low. It may be reasonable to discontinue DAPT after 42 days following non-flow diverting SAC of unruptured intracranial aneurysms.

Triple Aspiration versus Conventional Aspiration Techniques: A Randomized In Vitro Evaluation.

BACKGROUND AND PURPOSE: A single-aspiration maneuver using a large-volume syringe is a common and effective technique for aspiration thrombectomy. Multiple aspiration cycles using large aspiration syringes have been proposed as a means to improve the efficacy over single aspiration. In this study, we sought to investigate the efficacy of a "triple aspiration technique" in which a large-volume syringe is cycled 3 times before catheter retraction during aspiration thrombectomy. MATERIALS AND METHODS: A 3D-printed adult vasculature was used as a benchtop thrombectomy platform. Fibrin-rich and red blood cell-rich clots were prepared in centrifuge tubes using human plasma, red blood cells, and calcium chloride. Next, clots were placed in the carotid terminus of the model, and the performances of 3 different aspiration techniques-triple syringe, single syringe, and continuous pump aspiration-were compared in a randomized manner (1:1:1). Outcomes of interest included first-pass efficacy (FPE), complete clot removal (final modified TICI 2c/3), the number of thrombectomy attempts to achieve modified TICI 2c/3, vacuum pressure, and distal embolization. The distal emboli were detected using a 70-µm cell strainer placed at the outflow of the model and quantified using an image-processing algorithm. The vacuum pressures were measured using a pressure transducer. RESULTS: A total of 102 replicates were performed, 34 for each technique. The triple-aspiration technique provided a significantly higher rate of FPE than the syringe and pump aspiration techniques (67.6% versus 41.1%, P = .02). Additionally, the triple-aspiration technique achieved complete clot removal with a significantly lower mean number of thrombectomy attempts compared with single-syringe aspiration (1.2 [SD, 0.5] versus 1.8 [SD, 0.8], P = .005). The triple-aspiration technique generated significantly higher mean vacuum pressure than both the single-syringe and vacuum pump aspiration (28.3 [SD, 0.2] versus 27.2 [SD, 0.3], P = .002 and 26.2 [SD, 0.4], P = .001, respectively). The differences in complete clot removal and distal embolization parameters were not statistically significantly different across the groups. CONCLUSIONS: Our findings suggest that the triple aspiration technique can improve FPE rates and vacuum pressure in aspiration thrombectomy. Further studies are needed to examine the safety and efficacy of triple aspiration in the clinical setting.

Neuromodulation: What the neurointerventionalist needs to know.

Neuromodulation is the alteration of neural activity in the central, peripheral, or autonomic nervous systems. Consequently, this term lends itself to a variety of organ systems including but not limited to the cardiac, nervous, and even gastrointestinal systems. In this review, we provide a primer on neuromodulation, examining the various technological systems employed and neurological disorders targeted with this technology. Ultimately, we undergo a historical analysis of the field's development, pivotal discoveries and inventions gearing this review to neuro-adjacent subspecialties with a specific focus on neurointerventionalists.

Safety of the immediate use of nonsteroidal anti-inflammatory drugs after adult craniotomy for tumor.

OBJECTIVE: Poor pain control has a negative impact on postoperative recovery and patient satisfaction. However, overzealous pain management, particularly with opioids, can confound serial neurological assessments, increase morbidity, and predispose patients to long-term dependence. Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in treating postoperative pain and can limit opioid intake, but their use has been limited in patients undergoing craniotomy for brain tumor resection due to concerns of an increased hemorrhage risk. Herein, the authors aim to 1) address the safety of NSAID use in the immediate postoperative setting and 2) determine whether NSAID administration decreases opioid use following craniotomy for tumor resection in adult patients. METHODS: The authors conducted a retrospective cohort study of patients 18 years and older with an estimated glomerular filtration rate ≥ 60 ml/min/body surface area who had undergone craniotomy for tumor resection at their institution between 2019 and 2021. NSAID use in the first 48 hours following surgery was recorded. Primary outcomes were postoperative hemorrhage requiring a return to the operating room before hospital discharge and within 30 days of surgery. Secondary outcomes were more-than-minimal hemorrhage that did not require reoperation, acute kidney injury, and total opioid use within 48 hours after craniotomy. RESULTS: Among 1765 reviewed patient records, 1182 were eligible for inclusion in this analysis. Amid these records were 114 patients (9.6%) who had received at least one dose of an NSAID within 48 hours of their craniotomy. Four (0.3%) patients experienced bleeding requiring a return to operating room, one of whom was from the NSAID-treated group (RR 3.12, 95% CI 0.33-29.77, p = 0.30). No significant difference in nonoperative intracranial hemorrhage (RR 1.34, 95% CI 0.54-3.35, p = 0.53), postoperative acute kidney injury, or clinically significant extracranial bleeding was found between the NSAID and no-NSAID groups. Patients in the NSAID group had significantly higher oral morphine equivalent use (median 68 vs 30, p < 0.001). CONCLUSIONS: Postoperative NSAID use following craniotomy for tumor resection was not associated with an increased risk of hemorrhage requiring a return to the operating room. The authors noted higher opioid use in the patients treated with NSAIDs, which may reflect underlying reasons for the decision to treat patients with NSAIDs in the immediate postoperative period. These data warrant further investigation of NSAIDs as a safe, opioid-sparing postoperative pain management strategy in patients with normal kidney function who are undergoing intracranial tumor resection.

National Institutes of Health grant funding for cerebrovascular diseases.

BACKGROUND: Federal research funding is highly sought after but may be challenging to attain. A clear understanding of funding for specific diseases, such as cerebrovascular disorders, might help researchers regarding which National Institutes of Health (NIH) institutes fund research into specific disorders and grant types. OBJECTIVE: To examine the current scope of NIH grant funding for cerebrovascular conditions. METHODS: The NIH-developed RePORTER was used to extract active NIH-funded studies related to cerebrovascular diseases through January 2023. Duplicate studies were removed, and projects were manually screened and labeled in subcategories as clinical and basic science and as research subcategories. Extracted data included total funding, grant types, institutions that received funding, and diseases studied. Python (version 3.9) and SciPy library were used for statistical analyses. RESULTS: We identified 1232 cerebrovascular projects across seven diseases with US$699 952 926 in total funding. The cerebrovascular diseases with the greatest number of grants were ischemic stroke (705, or 57.2% of all funded projects), carotid disease (193, or 15.7%), and hemorrhagic stroke (163, or 13.2%). R01 grants were the most common mechanism of funding (632 grants, or 51.3%). The National Institute of Neurological Disorders and Stroke (NINDS) funded the most projects (504 projects; US$325 536 405), followed by the National Heart, Lung, and Blood Institute (NHLBI) (376 projects; US$216 784 546). CONCLUSION: Cerebrovascular disease receives roughly US$700 million in NIH funding. Ischemic stroke accounts for the majority of NIH-funded cerebrovascular projects, and R01 grants are the most common funding mechanism. Notably, NHLBI provides a large proportion of funding, in addition to NINDS.

Nonsteroidal Anti-inflammatory Medications in Cranial Neurosurgery: Balancing Opioid-Sparing Analgesia with Bleeding Risk.

Postcraniotomy pain is a common problem frequently encountered by neurosurgeons. This is typically managed with opioids; however, opioids have been shown to increase intracranial pressure by way of hypercapnia and straining from the associated constipation. Additionally, opioids can confound and mask the neurologic examination of postcraniotomy patients, as well as be the nidus for a potential opioid addiction. Thus, alternative solutions for opioids have been a major topic of investigation within the neurosurgical community. Nonsteroidal anti-inflammatory drugs (NSAIDs) present as a potential solution due to their nonaddictive and analgesic properties, but utilization of NSAIDs in neurosurgical patients has been controversial given that NSAIDs alter platelet function. The degree to which NSAIDs alter platelet function and bleeding time to a clinically relevant manner has remained controversial, although several well-designed studies concluded that the utilization of NSAIDs in post-craniotomy patients does not increase the risk of postoperative bleeding. Herein, we review the pharmacology, efficacy, and safety of NSAIDs with a particular emphasis on NSAID use for postintracranial neurosurgical procedure pain management.

Predicting disease progression and the need for tumor-directed treatment in tectal plate gliomas.

OBJECTIVE: Tectal plate gliomas are rare, slow-growing tumors of the midbrain that are discovered predominantly in the pediatric population. Because of their indolent nature, treatment mainly consists of observation and management of hydrocephalus. Unfortunately, a subset of tectal gliomas may exhibit tumor enlargement and disease progression. Currently, there are no established guidelines for predicting future progression of tectal gliomas or the need for tumor-directed treatment. In this paper, the authors present a large case series of tectal plate gliomas with the aim of determining early indicators of tumor progression and the need for tumor-directed treatment in a pediatric population, along with providing their experience in treating progressive tumors. METHODS: A retrospective chart review of 170 patients diagnosed with tectal plate glioma from a single institution, of whom 67 were pediatric patients (≤ 18 years of age), was performed. Univariate analysis was used to determine statistically significant predictors of symptomatic disease progression requiring eventual tumor-directed therapy. RESULTS: The median patient age of the full cohort was 24 years (range 0-73 years). Compared with the pediatric population, the adult population had more instances of incidental lesions (p < 0.001) and lower rates of hydrocephalus (50% vs 84%, p < 0.001). Of the pediatric patients who had ≥ 5 years of follow-up (n = 51), 12 (24%) experienced radiological progression and 13 (25%) required treatment for their tumor. The 1-year, 5-year, and 10-year radiographic progression-free survival (PFS) rates were 98%, 90%, and 86%, respectively. In univariate analysis, lesion involvement of the pons, moderate T1 hypointensity, and moderate contrast enhancement on baseline radiology were significantly associated with worse radiographic PFS. Alternatively, significant predictors of requiring tumor-directed treatment included extraocular eye movement abnormalities at presentation, involvement of the lesion beyond the tectum on baseline radiology, moderate T1 hypointensity, moderate contrast enhancement, and an increase in total lesion size during progression. At the most recent follow-up, 94% of the patients had stable/nonprogressive disease, 2% had progressive disease, and 4% died of tumor progression. CONCLUSIONS: Patients who demonstrate radiographic progression may not necessarily experience clinical/symptomatic progression or require tumor-directed treatment. Certain patient presentation characteristics and baseline radiographic features may be predictive of worse radiographic PFS or the need for future tumor-directed treatment in the pediatric population. Typically, the natural history of these lesions lends to excellent long-term survival, even in patients who experience clinical progression, should appropriate treatment be initiated.

Percutaneous transorbital transvenous embolization of a cavernous sinus dural arteriovenous fistula via the superior orbital fissure-technical video.

Carotid-cavernous dural arteriovenous fistulas causing debilitating ocular symptoms and/or retrograde cortical venous drainage necessitate curative treatment, which is achieved by disrupting the proximal draining vein. Transvenous embolization of carotid-cavernous dural arteriovenous fistulas can be achieved through the superior or inferior petrosal sinuses, facial veins, or superior ophthalmic veins.1, 2 However, if these approaches are not feasible, various percutaneous approaches have been described that use the skull base foramina to provide direct access to the cavernous sinus.3, 4 Here we present the case of a 54-year-old male with carotid-cavernous dural arteriovenous fistulas with cortical venous drainage causing diplopia that was cured using a percutaneous transorbital approach. We discuss the alternative endovascular strategies for treating carotid-cavernous dural arteriovenous fistulas and why they were not chosen, the technical nuances of the transorbital approach as well as the pearls and pitfalls of this seldom used technique. A comprehensive understanding of the many approaches for treating carotid-cavernous dural arteriovenous fistulas is important for neurointerventionalists.

Long-term outcomes following pipeline embolization of unruptured aneurysms.

BACKGROUND: Flow diversion using the pipeline embolization device (PED) for unruptured aneurysms is associated with high occlusion and low morbidity and mortality. However, most reports have limited follow-up of 1-2 years. Therefore, we sought to report our outcomes after PED for unruptured aneurysms in patients with at least 5-years of follow-up. METHODS: Review of patients undergoing PED for unruptured aneurysms from 2009 to 2016. RESULTS: Overall, 135 patients with 138 aneurysms were included for analysis. Seventy-eight percent of aneurysms (n=107) over a median radiographic follow-up of 5.0 years underwent complete occlusion. Among aneurysms with at least 5-years of radiographic follow-up (n=71), 79% (n=56) achieved complete obliteration. No aneurysm recanalized after radiographic obliteration. Furthermore, over a median clinical follow-up period of 4.9 years, 84% of patients (n=115) self-reported mRS scores between 0 and 2. For patients with at least 5-years of clinical follow-up, 88% (n=61) reported mRS between 0 and 2. In total, 3% (n=4) of patients experienced a major, non-fatal neurologic complication related to the PED, 5% (n=7) of patients experienced a minor neurologic complication related to PED placement, and 2% (n=3) died from either delayed aneurysm rupture, delayed ipsilateral hemorrhage after PED placement, or delayed (9 months after treatment) neural compression after progressive thrombosis of a PED-treated dolichoectactic vertebrobasilar aneurysm. CONCLUSIONS: Treatment of unruptured aneurysms with the PED is associated with high rates of long-term angiographic occlusion and low, albeit clinically important, rates of major neurologic morbidity and mortality. Thus, flow diversion via PED placement is safe, effective, and durable.

Sagittal Spinal Deformity in Patients with Idiopathic Normal Pressure Hydrocephalus.

AIM: To measure the baseline spinopelvic parameters and characterize the sagittal, and coronal plane deformities in patients with idiopathic normal pressure hydrocephalus (iNPH). MATERIAL AND METHODS: We analyzed a series of patients at one academic institution who underwent ventriculoperitoneal shunting for iNPH with pre-shunt standing full length x-rays. The series of patients was enrolled consecutively to minimize selection bias. We quantified comorbid sagittal plane spinal deformity based on the Scoliosis Research Society-Schwab classification system by assessing pelvic incidence and lumbar lordosis mismatch (PI-LL), pelvic tilt (PT), and sagittal vertical axis (SVA). RESULTS: Seventeen patients (59% male) were included in this study. Mean (± standard deviation) age was 74 ± 5.3 years with a body mass index (BMI) of 30 ± 4.5 kg/m < sup > 2< sup > . Six patients (35%) had marked sagittal plane spinal deformity by at least one parameter: five (29%) had greater than 20˚ PI-LL mismatch, three (18%) had > 9.5 cm SVA, and one (6%) had PT greater than 30˚. Additionally, the thoracic kyphosis exceeded the lumbar lordosis in nine patients (53%). CONCLUSION: Positive sagittal balance, with thoracic kyphosis exceeding lumbar lordosis, is common in iNPH patients. This may lead to postural instability, especially in patients whose gait does not improve following shunting. These patients may warrant further investigation and workup, including full length standing x-rays. Future studies should assess for improvement in the sagittal plane parameters following shunt placement.

Small symptomatic anterior communicating artery aneurysms: report of three cases and literature review.

PURPOSE: Given the anatomical relationship between the ACom complex and the optic nerve, small aneurysms of the ACom can present with visual symptoms. CASE REPORTS: We summarize and illustrate the clinical course of three patients with symptomatic small ACom aneurysms and collect similar other cases reported. RESULTS: Ten patients with small unruptured visually symptomatic anterior communicating artery aneurysms were found in the literature. Including three patients herein reported, the mean age at presentation was 56. The most common visual symptoms were bitemporal vision loss and/or a decrease in visual acuity. CONCLUSION: Unruptured aneurysms of the anterior communicating artery can present with visual symptoms due to compression of optic pathways, even at a small size. Prompt recognition and treatment of such a condition are paramount as new onset of visual symptoms can signify impending rupture akin to small PCom aneurysms compressing the third nerve. We discuss a few pitfalls of clipping small ACom aneurysms compressing the optic nerve.

Weathering the storm: a single-institution experience with paroxysmal sympathetic hyperactivity after brain tumor resection in pediatric patients.

OBJECTIVE: Paroxysmal sympathetic hyperactivity (PSH) is a complication of severe traumatic or hypoxic brain injury characterized by transient episodes of tachycardia, tachypnea, hypertension, hyperthermia, diaphoresis, and/or dystonic posturing. Posttraumatic "sympathetic storms" are associated with poor outcomes. PSH rarely occurs after brain tumor resection in pediatric patients; only 4 cases have been published since 1929. Thus, the authors sought to report their experience with postcraniotomy PSH in pediatric brain tumor patients. METHODS: A retrospective study of patients younger than 18 years of age who underwent craniotomy for brain tumor resection at a single center by a single surgeon over a 7-year period was performed. A clinical diagnosis of postoperative PSH was recorded. Recorded outcomes included the interval between surgery and initiation of cytotoxic therapy, need for long-term CSF diversion, length of hospital stay, and survival. RESULTS: Of the 150 patients who were included for analysis, 4 patients were diagnosed with postoperative PSH for an overall occurrence of 2.7%. PSH patients were younger than non-PSH patients (1.8 ± 0.4 years vs 9.2 ± 5.3 years, p = 0.010) and tended to have intraventricular tumors close to the thalamus, basal ganglia, and/or brainstem. PSH patients experienced longer hospital admissions (44.3 ± 23.4 days vs 6.8 ± 9.4 days, p = 0.001), a shorter interval between surgery and initiation of cytotoxic cancer-directed therapy (14.3 ± 8.0 days vs 90.7 days ± 232.9 days, p = 0.011), and increased need for long-term CSF diversion compared with non-PSH patients (75% vs 25%, p = 0.005). At the last follow-up, 50% of PSH patients had died compared with 13% of non-PSH patients (p = 0.094). CONCLUSIONS: PSH is a rare postoperative complication that may affect young children with periventricular tumors and is associated with poorer clinical outcomes. Increasing awareness of this condition is vital to improving patient outcomes.

Above-The-Hairline Suboccipital Transverse Approach for the Treatment of Chiari I Malformation.

BACKGROUND: Chiari I malformation is a common pediatric neurosurgical disorder with an established treatment paradigm. Posterior fossa decompression and duraplasty (PFDD) is associated with symptom improvement but it carries postoperative risk, particularly cerebrospinal fluid (CSF) leak and wound complications. In addition, the cosmetic outcomes of PFDD have been overlooked in the literature. OBJECTIVE: To describe a novel approach for PFDD in which the transverse surgical incision is completely hidden above the hairline and to report early outcomes in a prospective patient cohort. METHODS: Clinical and cosmetic outcomes were recorded for 15 consecutive pediatric patients who underwent PFDD for Chiari I malformation via the above-the-hairline transverse suboccipital approach. RESULTS: The median clinical follow-up time was 6 months (range 1-12 months), and the majority of patients experienced significant improvement of their preoperative symptoms. Three patients (20%) experienced complications associated with surgery, which included injury to the greater occipital nerve, CSF hypotension and subfascial pseudomeningocele, and superficial wound dehiscence that resolved spontaneously with oral antibiotics. Zero patients (0%) returned to the operating room for persistent CSF leak, deep wound infection, or revision decompression. An excellent cosmetic outcome was achieved in 12 patients (80%). No patient had a poor cosmetic outcome. CONCLUSION: The above-the-hairline transverse suboccipital approach for PFDD in patients with Chiari I malformation offers favorable cosmetic outcomes and fascial closure while permitting adequate decompression.

Microsurgical Obliteration of Craniocervical Junction Dural Arteriovenous Fistulas: Multicenter Experience.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports. OBJECTIVE: To report a multicenter experience assessing microsurgery safety/efficacy. METHODS: Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021). RESULTS: Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%. CONCLUSION: Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.

Stereotactic radiosurgery for intermediate- and high-grade arteriovenous malformations: outcomes stratified by the supplemented Spetzler-Martin grading system.

OBJECTIVE: The supplemented Spetzler-Martin (Supp-SM) grading system was developed to improve the predictive accuracy of surgical risk for patients with brain arteriovenous malformations (AVMs). The aim of this study was to apply the Supp-SM grading system to patients having stereotactic radiosurgery (SRS) for Spetzler-Martin (SM) intermediate- (grade III) or high-grade (grade IV-V) AVMs to enable comparison with published microsurgical series. METHODS: In 219 patients who underwent SRS during the period from 1990 to 2016, the Supp-SM grade was calculated for SM grade III (n = 154) or SM grade IV-V (n = 65) AVMs. The Supp-SM grades in these patients were 4 (n = 14, 6%), 5 (n = 36, 16%), 6 (n = 67, 31%), 7 (n = 76, 35%), and 8-9 (n = 26, 12%). Sixty patients (27%) had deep AVMs (basal ganglia, thalamus, or brainstem). Thirty-nine patients (18%) had volume-staged SRS; 41 patients (19%) underwent repeat SRS. The median follow-up period was 69 months for SM grade III AVMs and 113 months for SM grade IV-V AVMs. RESULTS: AVM obliteration was confirmed in 163 patients (74%) at a median of 38 months after initial SRS. The obliteration rates at 4 and 8 years were 59% and 76%, respectively. Thirty-one patients (14%) had post-SRS deficits from hemorrhage (n = 7, 3%) or radiation injury (n = 24, 11%). Six patients (3%) died after SRS (hemorrhage, n = 5; radiation injury, n = 1). The rates of neurological decline or death at 4 and 8 years were 11% and 18%, respectively. Factors predictive of nonobliteration were deep location (HR 0.57, 95% CI 0.39-0.82, p = 0.003) and increasing AVM volume (HR 0.96, 95% CI 0.93-0.99, p = 0.002). Increasing AVM volume was the only factor associated with neurological decline (HR 1.05, 95% CI 1.02-1.08, p = 0.002). The Supp-SM grading score did not correlate with either obliteration (HR 0.94, 95% CI 0.82-1.09, p = 0.43) or neurological decline (HR 1.15, 95% CI 0.84-1.56, p = 0.38). CONCLUSIONS: The Supp-SM grading system was not predictive of outcomes after SRS of intermediate- or high-grade AVM. In a cohort that included a high percentage (47%) of "inoperable" AVMs according to Supp-SM grade (≥ 7), most patients had obliteration after SRS, although there was a high risk of neurological decline.

Iatrogenic vertebral artery injury with concomitant contralateral idiopathic vertebral artery dissection managed with intravascular intervention: a case report.

Background: Vertebral artery injury (VAI) is a known potential complication of posterior cervical fusion surgery. Pre-operative imaging is used to determine the patency of bilateral vertebral arteries during the planning and execution of surgery. This case illustrates an example of a staged anterior/posterior cervical reconstruction in which an iatrogenic VAI combined with a contralateral idiopathic vertebral artery dissection not identified on pre-operative imaging resulted in absent basilar artery anterograde flow. Case Description: A 61-year-old female underwent planned staged anterior cervical decompression C4-T1 with posterior cervical fusion C2-T4 for the treatment of degenerative cervical myeloradiculopathy. During the second stage posterior fusion, iatrogenic VAI occurred during drilling for placement of the right C2 pars screw. Upon post-operative angiography, in addition to the known right VAI, there was a new left vertebral artery dissection that occurred during/after the anterior stage. The basilar artery was only filled in retrograde fashion from the right internal carotid artery across the right posterior communicating artery. The left vertebral artery dissection was treated with telescoping flow diverting stents to restore flow to the basilar artery and the right VAI was treated with coiling. Conclusions: Surgeons should be aware of the possibility, while rare, that an occult injury to the non-injured artery is always a possibility if significant deformity correction or alignment change has occurred during cervical spine surgery. Working closely with neurointerventional colleagues can be invaluable to quickly assess and if necessary, restore blood flow to the brain through these life saving techniques.

Right posterior petrosectomy for resection of petroclival meningioma.

Petroclival meningiomas, which arise from the upper two-thirds of the clivus and are medial to the trigeminal nerve, carry significant surgical risk. Patients whose operations are tailored to maximize tumor resection while minimizing neurological morbidity have favorable outcomes. Subtotally resected tumors can be subsequently considered for radiosurgery in an attempt to limit recurrence. Here the authors report the case of a 40-year-old woman with postpartum trigeminal neuropathy secondary to a petroclival meningioma. The patient underwent an aggressive subtotal resection via a posterior petrosal approach with preservation of neurological function followed by adjuvant radiosurgery. The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21227.