Intraoperative angiography in neurosurgery: temporal trend, access site, and operative indication considerations from a 6-year institutional experience.

BACKGROUND: Historically, the transfemoral approach (TFA) has been the most common access site for cerebral intraoperative angiography (IOA). However, in line with trends in cardiac interventional vascular access preferences, the transradial approach (TRA) and transulnar approach (TUA) have been gaining popularity owing to favorable safety and patient satisfaction outcomes. OBJECTIVE: To compare the efficacy and safety of TRA/TUA and TFA for cerebral and spinal IOA at an institutional level over a 6-year period. METHODS: Between July 2016 and December 2022, 317 angiograms were included in our analysis, comprising 60 TRA, 10 TUA, 243 TFA, and 4 transpopliteal approach cases. Fluoroscopy time, contrast dose, reference air kerma, and dose-area products per target vessel catheterized were primary endpoints. Multivariate regression analyses were conducted to evaluate predictors of elevated contrast dose and radiation exposure and to assess time trends in access site selection. RESULTS: Contrast dose and radiation exposure metrics per vessel catheterized were not significantly different between access site groups when controlling for patient position, operative region, 3D rotational angiography use, and different operators. Access site was not a significant independent predictor of elevated radiation exposure or contrast dose. There was a significant relationship between case number and operative indication over the study period (P<0.001), with a decrease in the proportion of cases for aneurysm treatment offset by increases in total cases for the management of arteriovenous malformation, AVF, and moyamoya disease. CONCLUSIONS: TRA and TUA are safe and effective access site options for neurointerventional procedures that are increasingly used for IOA.

Microvascular reperfusion during endovascular therapy: the balance of supply and demand.

BACKGROUND: Endovascular therapy (EVT) has revolutionized the treatment of acute stroke, but large vessel recanalization does not always result in tissue-level reperfusion. Cerebral blood flow (CBF) is not routinely monitored during EVT. We aimed to leverage diffuse correlation spectroscopy (DCS), a novel transcranial optical imaging technique, to assess the relationship between microvascular CBF and post-EVT outcomes. METHODS: Frontal lobe CBF was monitored by DCS in 40 patients undergoing EVT. Baseline CBF deficit was calculated as the percentage of CBF impairment on pre-EVT CT perfusion. Microvascular reperfusion was calculated as the percentage increase in DCS-derived CBF that occurred with recanalization. The adequacy of reperfusion was defined by persistent CBF deficit, calculated as: baseline CBF deficit - microvascular reperfusion. A good functional outcome was defined as 90-day modified Rankin Scale score ≤2. RESULTS: Thirty-six of 40 patients achieved successful recanalization, in whom microvascular reperfusion in itself was not associated with infarct volume or functional outcome. However, patients with good functional outcomes had a smaller persistent CBF deficit (median 1% (IQR -11%-16%)) than patients with poor outcomes (median 28% (IQR 2-50%)) (p=0.02). Smaller persistent CBF deficit was also associated with smaller infarct volume (p=0.004). Multivariate models confirmed that persistent CBF deficit was independently associated with infarct volume and functional outcome. CONCLUSIONS: CBF augmentation alone does not predict post-EVT outcomes, but when microvascular reperfusion closely matches the baseline CBF deficit, patients experience favorable clinical and radiographic outcomes. By recognizing inadequate reperfusion, bedside CBF monitoring may provide opportunities to personalize post-EVT care aimed at CBF optimization.

Feasibility and safety of transradial intraoperative angiography for neurosurgery: An institutional experience.

BACKGROUND: Transradial approach for neuroangiography is becoming increasingly popular because of the advantages demonstrated by interventional cardiology. Many advantages of radial access could be applied to intraoperative angiography. OBJECTIVE: To report our institutional experience with transradial and transulnar intraoperative angiography, and evaluate its safety and feasibility. METHODS: Intraoperative angiography through upper extremity vessels was attempted in 70 consecutive patients between April 2019 and December 2022. Data on patient characteristics and surgical indications, procedural variables, and complications were collected. RESULTS: Of the 70 patients who underwent intraoperative angiography, 58.6% were female, and the mean age was 52.9 ± 14.0 years. The reason for surgery was aneurysm clipping in 42 (60.0%) cases. In total, 55 patients (78.6%) were positioned supine, 13 (18.6%) prone, and two (2.9%) were positioned three-quarters prone. Access was attempted via the radial artery in 60 (85.7%) patients and the ulnar artery in 10 (14.3%) patients. The procedure was successful in 69 of 70 cases (98.6%), as one required conversion to transfemoral approach due to significant spasm in the proximal right radial artery. The median fluoroscopy time was 8 min. No procedure was aborted, and no patient experienced access-site or angiography-related complications. Intraoperative angiography altered the surgical management in 3 (4.3%) cases. Re-access for follow-up angiography was unsuccessful in three (13.6%) of 22 due to radial artery occlusion. CONCLUSIONS: Our institutional experience supports that transradial and transulnar intraoperative angiography is safe and feasible during neurovascular procedures for various indications and positions.

Bilateral retinal hemorrhages after sequential endovascular treatment of bilateral unruptured cerebral aneurysms.

PURPOSE: To report a case of bilateral retinal hemorrhages in a patient undergoing two separate endovascular interventions for bilateral cerebral aneurysms. METHODS: A comprehensive ophthalmic examination was performed after the patient underwent each of two separate endovascular interventions for bilateral cerebral aneurysms. Multimodal imaging including widefield pseudocolor fundus photography, optical coherence tomography, and widefield fluorescein angiography (FA) was obtained. A systemic workup including genetic testing and hypercoagulability studies was performed. RESULTS: Dilated fundus examination revealed new visually significant ipsilateral retinal hemorrhages after each endovascular procedure. FA showed evidence of a peripheral retinal microangiopathy present in both eyes before the patient underwent her second endovascular procedure. Systemic workup revealed persistently elevated serum anticardiolipin IgM antibody levels at >99th percentile. CONCLUSION: Retinal complications after endovascular intracranial interventions are uncommon. This patient who developed bilateral retinal complications was found to have persistently elevated anticardiolipin antibody levels, a risk factor for thrombosis. Patients who develop retinal complications after endovascular intracranial intervention may benefit from systemic workup for hypercoagulable conditions.

Endoscopic fenestration of an enlarging giant occipital arachnoid cyst.

This case demonstrates an endoscopic fenestration of an enlarging giant occipital arachnoid cyst. The patient is a 42-year-old woman presenting with headache, progressive vision loss, and nausea and vomiting. MRI demonstrates a large, nonenhancing cystic lesion in the right occipital lobe measuring up to 8.3 cm, consistent with an arachnoid cyst. This surgical video illustrates the technique for an endoscopic fenestration into the native ventricular system utilizing stereotactic MRI-guided stealth navigation. Postoperatively, the patient had full recovery with improvement of headaches and vision and was discharged on postoperative day 1 without complications. The video can be found here: https://stream.cadmore.media/r10.3171/2023.1.FOCVID22129.

Interhemispheric gravity-assisted approach for microsurgical resection of a splenium arteriovenous malformation.

The parietal interhemispheric approach employing gravity retraction with skeletonization of bridging veins provides an excellent operative window for safe, curative resection of splenial arteriovenous malformations.

Diagnostic Yield and Utility of Radiographic Imaging in the Evaluation of Pulsatile Tinnitus: A Systematic Review.

Objective: The objective of this study is to assess diagnostic yield of imaging modalities used to evaluate patients presenting with pulsatile tinnitus (PT). Databases Reviewed: PubMed, Embase, and Scopus were queried using the search terms "pulsatile tinnitus," "pulse-synchronous tinnitus," and "pulse synchronous tinnitus" with no date limitations. Methods: Studies that reported diagnostic imaging for patients presenting with PT were included. Data were reviewed for sample size, gender, age, imaging study, indications, and diagnoses. The primary outcome measure from aggregated data was the yield of positive diagnoses made with each imaging modality. The quality of evidence was assessed for risk of bias. Results: From an initial search of 1145 articles, 17 manuscripts met inclusion criteria, of which 12 studies evaluated individual imaging modalities. The number of unique patients included was 1232. The diagnostic yield varied between modalities: carotid ultrasound (21%, 95% confidence interval [CI]: 12%-35%), CT temporal bone (65%, CI: 20%-93%), computed tomographic angiography (86%, CI: 80%-90%), and MRI/magnetic resonance angiography (58%, CI: 43%-72%). Conclusion: Studies on the diagnostic approach to PT are limited by heterogeneity in both inclusion criteria and reporting standards. A wide range of imaging modalities are used in practice during the initial evaluation of PT, and the diagnostic yield for imaging can be improved by utilizing more specific clinical indications.

A complex anterior communicating artery aneurysm projecting into the sella turcica.

Intrasellar aneurysms are rare vascular lesions that typically present with symptoms of mass effect upon the pituitary gland and optic apparatus. Most arise from the internal carotid artery, while only a handful of case reports describe intrasellar aneurysms originating from the anterior communicating artery. The appropriate recognition and management of these lesions are critical to prevent irreversible neurological deficits and catastrophic hemorrhage. Here, we highlight a patient with an anterior communicating artery aneurysm projecting into the sella turcica, leading to hyponatremia, pituitary dysfunction, and chiasmal compression.

The Pennsylvania Postmarket Multicenter Experience With Flow Redirection Endoluminal Device.

BACKGROUND: The flow redirection endoluminal device (FRED) is a novel self-expanding double-layer nitinol braided flow diverter that recently received FDA approval. However, early postmarket studies from the United States are lacking. OBJECTIVE: To report our short-term multicenter experience. METHODS: Series of consecutive patients undergoing FRED treatment for intracranial aneurysms were queried from prospectively maintained registries at 4 North-American Centers in Pennsylvania (February 2020-June 2021). The pertinent baseline demographics, aneurysmal characteristics, and procedural outcomes were collected and analyzed, with primary outcome of aneurysmal occlusion and secondary outcome of safety and complications. RESULTS: Sixty-one patients (median age 58 years, 82% female) underwent 65 FRED treatment procedures for 72 aneurysms. Most (86.1%) of the aneurysms were unruptured; 80.5% were saccular in morphology, and 87.5% were located along the internal carotid artery, with a median size of 7.1 mm (IQR 5.2-11.9 mm). Radiographic follow-up was available in 86.1% of the aneurysms, showing complete occlusion in 74.2% (80% in catheter angiography-only group), and near-complete occlusion in 11.3% of the cases (median 6.3 months), with 2.8% re-treated. Permanent ischemic complications were encountered in 2.8% of the cases, with no procedural mortality. A modified Rankin Scale of 0 to 2 was documented in 98.1% of the patients at the last clinical follow-up (median 6.1 months). CONCLUSION: The results of the early postmarket experience with the FRED device show reasonable safety and adequate aneurysmal occlusion rates comparable with other flow diverters. However, more extensive multicenter studies with more extended follow-up data are needed to assess the long-term safety and durability of the device.

Endoscopic fenestration of a giant frontal arachnoid cyst: Operative technique and anatomical nuances.

Endoscopic fenestration is best as it is minimally invasive and does not require hardware in the surgical site (Figure 1). This case shows the safety of endoscopic fenestration and the utility of operative adjuncts (J Korean Med Sci. 1999;14:443; Neurosurg Focus. 2005;19:E7).

Highly Visible Wall-Timer to Reduce Endovascular Treatment Time for Stroke.

BACKGROUND: Endovascular therapy for acute ischemic stroke has revolutionized clinical care for patients with stroke and large vessel occlusion, but treatment remains time sensitive. At our stroke center, up to half of the door-to-groin time is accounted for after the patient arrives in the angio-suite. Here, we apply the concept of a highly visible timer in the angio-suite to quantify the impact on endovascular treatment time. METHODS: This was a single-center prospective pseudorandomized study conducted over a 32-week period. Pseudorandomization was achieved by turning the timer on and off in 2-week intervals. The primary outcome was angio-suite-to-groin time, and secondary outcomes were angio-suite-to-intubation time, groin-to-recanalization time, and 90-day modified Rankin scale. A stratified analysis was performed based on type of anesthesia (ie, endotracheal intubation versus not). RESULTS: During the 32-week study period, 97 mechanical thrombectomies were performed. The timer was on and off for 38 and 59 cases, respectively. The timer resulted in faster angio-suite-to-groin time (28 versus 33 minutes; P=0.02). The 5-minute reduction in angio-suite-to-groin was maintained after adjusting for intubation status in a multivariate regression (P=0.02). There was no difference in the 90-day modified Rankin scale between groups. The timer impact was consistent across the 32-week study period. CONCLUSIONS: A highly visible timer in the angio-suite achieved a meaningful, albeit modest, reduction in endovascular treatment time for patients with stroke. Given the lack of risk and low cost, it is reasonable for stroke centers to consider a highly visible timer in the angio-suite to improve treatment times.

Radiosurgery as a microsurgical adjunct: outcomes after microsurgical resection of intracranial arteriovenous malformations previously treated with stereotactic radiosurgery.

OBJECTIVE: Microsurgical resection of arteriovenous malformations (AVMs) can be aided by staged treatment consisting of stereotactic radiosurgery followed by resection in a delayed fashion. This approach is particularly useful for high Spetzler-Martin (SM) grade lesions because radiosurgery can reduce flow through the AVM, downgrade the SM rating, and induce histopathological changes that additively render the AVM more manageable for resection. The authors present their 28-year experience in managing AVMs with adjunctive radiosurgery followed by resection. METHODS: The authors retrospectively reviewed records of patients treated for cerebral AVMs at their institution between January 1990 and August 2019. All patients who underwent stereotactic radiosurgery (with or without embolization), followed by resection, were included in the study. Of 1245 patients, 95 met the eligibility criteria. Univariate and multivariate regression analyses were performed to assess relationships between key variables and clinical outcomes. RESULTS: The majority of lesions treated (53.9%) were high grade (SM grade IV-V), 31.5% were intermediate (SM grade III), and 16.6% were low grade (SM grade I-II). Hemorrhage was the initial presenting sign in half of all patients (49.5%). Complete resection was achieved among 84% of patients, whereas 16% had partial resection, the majority of whom received additional radiosurgery. Modified Rankin Scale (mRS) scores of 0-2 were achieved in 79.8% of patients, and 20.2% had poor (mRS scores 3-6) outcomes. Improved (44.8%) or stable (19%) mRS scores were observed among 63.8% of patients, whereas 36.2% had a decline in mRS scores. This includes 22 patients (23.4%) with AVM hemorrhage and 6 deaths (6.7%) outside the perioperative period but prior to AVM obliteration. CONCLUSIONS: Stereotactic radiosurgery is a useful adjunct in the presurgical management of cerebral AVMs. Multimodal therapy allowed for high rates of AVM obliteration and acceptable morbidity rates, despite the predominance of high-grade lesions in this series of patients.

Carotid artery revascularization using the Walrus balloon guide catheter: safety and feasibility from a US multicenter experience.

INTRODUCTION: The Walrus balloon guide catheter (BGC) is a new generation of BGC, designed to eliminate conventional limitations during mechanical thrombectomy. OBJECTIVE: To report a multi-institutional experience using this BGC for proximal flow control (PFC) in the setting of carotid artery angioplasty/stenting (CAS) in elective (eCAS) and tandem strokes (tCAS). METHODS: Prospectively maintained databases at 8 North American centers were queried to identify patients with cervical carotid disease undergoing eCAS/tCAS with a Walrus BGC. RESULTS: 110 patients (median age 68, 64.6% male), 80 (72.7%) undergoing eCAS and 30 (27.3%) tCAS procedures, were included (median cervical carotid stenosis 90%; 46 (41.8%) with contralateral stenosis). Using a proximal flow-arrest technique in 95 (87.2%) and flow-reversal in 14 (12.8%) procedures, the Walrus was navigated into the common carotid artery successfully in all cases despite challenging arch anatomy (31, 28.2%), with preferred femoral access (103, 93.6%) and in monitored anesthesia care (90, 81.8%). Angioplasty and distal embolic protection devices (EPDs) were used in 91 (83.7%) and 58 (52.7%) procedures, respectively. tCAS led to a modified Thrombolysis in Cerebral Infarction 2b/3 in all cases. Periprocedural ischemic stroke (up to 30 days postoperatively) rate was 0.9% (n=1) and remote complications occurred in 2 (1.8%) cases. Last follow-up modified Rankin Scale score of 0-2 was seen in 95.3% of eCAS cohort, with no differences in complications in the eCAS subgroup between PFC only versus PFC and distal EPD (median follow-up 4.1 months). CONCLUSION: Walrus BGC for proximal flow control is safe and effective during eCAS and tCAS. Procedural success was achieved in all cases, with favorable safety and functional outcomes on short-term follow-up.

Artery of Davidoff and Schechter: A Large Angiographic Case Series of Dural AV Fistulas.

The artery of Davidoff and Schechter (ADS) is the only meningeal branch of the posterior cerebral artery (PCA), supplying the medial tentorial margin and posterior portions of the falx. Given its small size, it is rarely identified on angiographic studies, unless enlarged in pathologies such as dural arteriovenous fistulas (DAVFs) or vascularized masses. This artery was first described by Wollschlaeger and Wollschlaeger in 1965, and to date, only a few reports have described its significance. The objective of this study is to report our experience with the ADS in dural fistulas from 2 tertiary medical centers and to emphasize the importance of recognizing this artery during angiographic examination of vascular tentorial and posterior fossa lesions. To our knowledge, this report demonstrates the largest angiographic case series published to date, recognizing a total of 7 patients with ADS arising secondary to a posterior fossa or tentorial DAVF and one of the largest reported series of DAVFs supplied by the ADS treated by endovascular and surgical techniques. Our cases validate the importance of prompt identification of the ADS for the diagnosis as well as endovascular treatment of vascular malformations in the posterior fossa and tentorial region.

Endovascular Transcarotid Artery Revascularization Using the Walrus Balloon Guide Catheter: Preliminary Experience.

BACKGROUND: The Walrus Balloon Guided System Catheter is a new generation of balloon guide catheter (BGC) designed to bypass some technical limitations of conventional BGC devices. Their utility in cervical carotid disease treatment has not been reported. We report our preliminary experience in cervical carotid treatment using the Walrus BGC to perform a modified endovascular transcarotid artery revascularization technique. METHODS: Patients with cervical carotid disease undergoing endovascular treatment using the Walrus BGC at our institution were identified. The pertinent baseline demographics and procedural outcomes were collected and analyzed. RESULTS: Twelve patients were included (median age, 70; 58.3% females). All patients had an imaging-confirmed cervical carotid disease that indicated intervention: 6 with high-grade cervical arteriosclerotic carotid stenosis, 2 with intraluminal thrombi, 1 with traumatic carotid dissection, and 3 patients with cervical carotid tandem occlusion along with acute ischemic stroke secondary to large vessel occlusion that required mechanical thrombectomy. Carotid artery stenting was performed in all cases, except 2 of the 3 mechanical thrombectomy cases (angioplasty only). All patients had at least periprocedural follow-up of 30 days, with no stroke, myocardial infarction, or death encountered. CONCLUSIONS: We describe a modified endovascular transcarotid artery revascularization technique. We used a standard femoral access to navigate the Walrus catheter in the common carotid artery, followed by balloon inflation for proximal flow arrest or flow reversal (when connected to the aspiration pump) to deploy the carotid stent across the stenosis, while avoiding distal external carotid artery balloon occlusion. Successful treatment was achieved in all cases, with no periprocedural complications encountered.

Resolution of hypoglossal nerve palsy after coil embolization of an anterior condylar confluence fistula.

A 69-year-old female presented with 2-year history of slurred speech, left-sided pulsatile tinnitus, and left-sided hypoglossal nerve palsy. Cerebral angiography demonstrated a left anterior condylar confluence fistula. She was treated with a transvenous coil embolization of the left condylar fistula pocket.

Eagle syndrome: a rare pathology presented in a 3-Dimensional reconstructed view.

A 42-year-old male presented with 3-month history of constant right-sided frontal headaches, severe right-sided intermittent sharp jaw pain, odynophagia, globus pharyngis, and worsening episodes of blurry vision in his right eye. Cervicocerebral angiography demonstrated a prominent, 4 cm right sided styloid process with close proximity to the right internal carotid artery (ICA). The patient was referred to otorhinolaryngology for styloidectomy and continued care.

Microsurgical Clip Reconstruction of a Ruptured Internal Carotid Artery Terminus Blister Aneurysm Using a Reverse Picket Fence Technique.

BACKGROUND: Blister aneurysms are rare, technically challenging lesions that are typically ill defined and arise at nonbranch points of arteries. OBJECTIVE: To describe the microsurgical treatment of a ruptured blister aneurysm at the internal carotid artery (ICA) terminus using the reverse picket fence clipping technique. METHODS: The patient was a 60-yr-old male. He presented with a Hunt and Hess Grade 2, Fisher Grade 3 subarachnoid hemorrhage located in the bilateral sylvian fissures (right > left) and suprasellar cisterns. Computed tomography angiography demonstrated 2 aneurysms: a 2-mm right middle cerebral artery (MCA) aneurysm and a 2.5-mm right internal carotid artery (ICA) terminus blister aneurysm. Transradial cerebral angiography was undertaken which showed these similar sized aneurysms. Microsurgical treatment was chosen, and the patient underwent a right pterional craniotomy for clipping of his aneurysms. The patient consented to the procedure. RESULTS: The combination of stacked fenestrated clips repaired the vessel, with intraoperative fluorescein and indocyanine green angiography demonstrated normal filling of the MCA and ICA circulation with no delay. Intraoperative angiography confirmed induced moderate stenosis of the ICA terminus at about 50%, which is essential to close the blister aneurysm site by utilizing a portion of the normal vessel wall. CONCLUSION: Ruptured blister aneurysms at the ICA terminus can be safely repaired using the reverse picket fence technique for clipping.

Combined Endovascular and Microsurgical Management of a Tentorial Arteriovenous Malformation in a Hybrid Neurovascular Operating Room: 2-Dimensional Operative Video.

Tentorial margin arteriovenous malformations (AVMs) at the cerebello-mesencephalic fissure are deep lesions, which can be safely resected via a lateral supracerebellar infratentorial approach. This video illustrates the case of a patient who presented with hemorrhage from a tentorial AVM. He was managed in the hybrid neurovascular operating room with Onyx (Medtronic) embolization of a superior cerebellar artery feeder followed by resection of the AVM, which included cerebellar relaxation from lumbar cerebrospinal fluid (CSF) drainage and lateral positioning. Wide cisternal arachnoid dissection at the quadrigeminal cistern allowed for a straight trajectory to the AVM without fixed retraction. Intraoperative transradial angiography confirmed complete AVM exclusion. This video was deemed Institutional Review Board (IRB) exempt by the University of Pennsylvania IRB as it is considered a case report, which does not require IRB approval or patient consent. The patient consented to the procedure.

Tentorial Dural Arteriovenous Fistulas as a Cause of Thalamic Edema: 2 Cases of an Important Differential Diagnosis to Consider.

The differential diagnosis for bilateral thalamic edema is extensive and includes vascular, neoplastic, metabolic, and infectious causes. Of the vascular causes of thalamic edema, arterial and venous infarctions are well-documented, but dural arteriovenous fistulas (dAVFs) are a relatively uncommon and widely underrecognized cause of thalamic edema. Dural AVFs are notoriously difficult to diagnose clinically, especially in the absence of hemorrhage, and cross-sectional imaging findings can be subtle. This can result in a delayed diagnosis, and occasionally, an invasive biopsy for further clarification of a purely vascular disease. In this review, we detail our experience with the imaging diagnosis of dAVF as a cause of thalamic edema and present a short differential of other vascular causes.