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.

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.

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.

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.

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).

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.

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.

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.

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.

Type V Dural Arteriovenous Fistula Supplied by the Artery of Wollschlaeger and Wollschlaeger Causing Cervical Myelopathy and Quadriparesis.

BACKGROUND: The artery of Wollschlaeger and Wollschlaeger is a tentorial branch of the superior cerebellar artery that is usually not visualized on conventional cerebral angiography, unless it is pathologically enlarged. It can be recruited as part of the blood supply to tentorial dural arteriovenous fistulas (AVFs), although this occurs infrequently. CASE DESCRIPTION: Here we report the clinico-radiologic evaluation and treatment of a 48-year-old man referred to our institution for hitherto workup negative progressive, relapsing quadriparesis. This represents the first reported case of cervical myelopathy caused by venous congestion from a type V dural AVF supplied by the artery of Wollschlaeger and Wollschlaeger. CONCLUSIONS: The anatomic discrepancy between the symptomatic spinal cord lesion and the etiologic intracranial fistula frequently results in delayed care in cases of myelopathy due to intracranial dural AVFs. Familiarity with these disorders and of their pathophysiologic mechanisms is important to avoid unnecessary diagnostic delays.

Microsurgical Trapping and Excision of Ruptured Mycotic Aneurysms in a Patient with Mitral Valve Endocarditis: A Surgical Technique.

This case Video 1 demonstrates a microsurgical technique for trapping and excision of 2 ruptured mycotic aneurysms. The patient was a 64-year-old man with severe mitral regurgitation and valvular vegetations suggestive of endocarditis. On examination, the patient presented with speech difficulty. Preoperative imaging showed a large left temporoparietal intracerebral hemorrhage and associated sulcal subarachnoid hemorrhage from 2 distal aneurysms of the left middle cerebral artery. In the presence of ruptured aneurysms in a patient who requires anticoagulation for valve replacement, endovascular options are limited. For aneurysms located in an eloquent area in the left hemisphere, microsurgical treatment with small corridors can facilitate excision and minimize damage to the surrounding tissue. As such, the patient was treated with microsurgical trapping and excision of the aneurysms followed by evacuation of intraparenchymal hemorrhage using stereotactic navigation. Intraoperative neurophysiologic monitoring was used to prepare for a potential bypass in the event of inadequate collaterals or changes in neurophysiologic potentials. Postoperatively, the patient remained symmetric in his motor strength and had improved speech deficits, indicative of an uneventful recovery. The patient was cleared for full anticoagulation and valve replacement on postoperative day 10. The patient underwent intravenous antibiotic therapy with ceftriaxone before undergoing mitral valve replacement by cardiac surgery.

Endoscopic Paramedian Sitting Craniotomy for Resection of a Dorsal Midbrain Cavernous Malformation: 2-Dimensional Operative Video.

This case video demonstrates the surgical technique for resection of a cavernous malformation in the right dorsal midbrain. This video was deemed exempt by the University of Pennsylvania Institutional Review Board (IRB), as it is considered a case report, which does not require IRB approval or patient consent. The patient was a 57-yr-old male with cerebral cavernous malformation syndrome with multiple intracranial cavernomas. He was noticed to have progressively slowed speech with worsening confusion and drowsiness. On exam, the patient exhibited worsening in swallowing and upward gaze paresis, secondary to Parinaud phenomena. The patient was treated with microsurgical resection, utilizing stereotactic navigation and intraoperative neurophysiologic monitoring. Intraoperative view provided in the video was captured using a Karl Storz Endoscope (Karl Storz SE & Co KG, Tuttlingen, Germany). Postoperatively, the patient had worsening double vision, which improved on follow-up, in addition to improvement in sensorium and swallowing.

Contralateral Transcingulate Resection of Midcingulate Cavernous Malformation.

This case video demonstrates the surgical technique for resection of a cavernous malformation in the midleft cingulate gyrus using a contralateral transcingulate approach (Video 1). The indications for operating on a cavernoma such as this are seizures, recurrent hemorrhages, and a surgically resectable target. This video describes the operative steps, positioning, incision, and craniotomy for this approach. In addition, risks of air embolism, interhemispheric exposure, use of stereotactic navigation, and benefits of gravity retraction are highlighted. The contralateral transcingulate approach is indicated as it reduces the need for retraction by employing gravity retraction. Further, this approach is advantageous as it prevents injury to the left sided eloquent cortex, affords comfortable surgeon position and offers an improved trajectory. This case illustrates a well-described albeit unique surgical technique for cavernous malformation repair in an operative video format. In addition, this case shows that this technique results in a favorable patient outcome with minimal complication when appropriately used.

Microsurgical clipping of an unruptured superiorly projecting ACoM aneurysm in a rotated ACoM complex.

This case illustrates surgical technique for wide neck aneurysm clipping in a rotated complex and how to manage intraoperative aneurysm rupture while maintaining hemostasis (Cai et al., Anterior communicating artery aneurysm morphology and the risk of rupture. World Neurosurg. 2018;109:119 and Dehdashti et al., The implication of anterior communicating complex rotation and 3-dimensional computerized tomography angiography findings in surgical approach to anterior communicating artery aneurysms. World Neurosurg. 2016;91:34).

Transcranial Optical Monitoring of Cerebral Hemodynamics in Acute Stroke Patients during Mechanical Thrombectomy.

INTRODUCTION: Mechanical thrombectomy is revolutionizing treatment of acute stroke due to large vessel occlusion (LVO). Unfortunately, use of the modified Thrombolysis in Cerebral Infarction score (mTICI) to characterize recanalization of the cerebral vasculature does not address microvascular perfusion of the distal parenchyma, nor provide more than a vascular "snapshot." Thus, little is known about tissue-level hemodynamic consequences of LVO recanalization. Diffuse correlation spectroscopy (DCS) and diffuse optical spectroscopy (DOS) are promising methods for continuous, noninvasive, contrast-free transcranial monitoring of cerebral microvasculature. METHODS: Here, we use a combined DCS/DOS system to monitor frontal lobe hemodynamic changes during endovascular treatment of 2 patients with ischemic stroke due to internal carotid artery (ICA) occlusions. RESULTS AND DISCUSSION: The monitoring instrument identified a recanalization-induced increase in ipsilateral cerebral blood flow (CBF) with little or no concurrent change in contralateral CBF and extracerebral blood flow. The results suggest that diffuse optical monitoring is sensitive to intracerebral hemodynamics in patients with ICA occlusion and can measure microvascular responses to mechanical thrombectomy.

Aneurysm Dome Excision and Picket Fence Clip Reconstruction of a Previously Coiled Recurrent Giant Middle Cerebral Artery Aneurysm: Technical Nuances.

This video case illustrates key surgical steps required in safe management of a giant recurrent previously coiled middle cerebral artery (MCA) aneurysm (Video 1). The patient described in this case was a 68-year-old man who presented with sudden-onset severe headache and dizziness. The patient had a history of a prior coil embolization of a 12-mm left middle cerebral artery aneurysm at an outside hospital. Imaging demonstrated recurrence now of a giant left middle cerebral artery aneurysm with coil compaction and left temporal lobe edema. Magnetic resonance imaging further demonstrated thrombus in the aneurysm and aneurysm wall enhancement concerning for impending rupture. Given the aneurysm size, imaging features, and mass effect, the aneurysm was treated with microsurgical clipping. This case is valuable to the literature with a clear video case illustration of aneurysm dome excision, aneurysm endarterectomy, and picket fence aneurysm neck reconstruction. Aneurysm dome excision is critical for treatment of giant aneurysms causing mass effect and was only used in this case because thrombus and coil mass did not allow for direct clipping across the neck without compromise of the MCA M2 branch. Hence, this video highlights key technical tenets, such as safe thrombus removal and adequate cleaning of the endoluminal surface and preparedness for bypass in challenging cases.

Microsurgical Clip Reconstruction of Ruptured Dissecting PICA Aneurysm: 2-Dimensional Operative Video.

This case is a presentation of technical tenets for the microsurgical clipping of a ruptured posterior inferior cerebellar artery (PICA) aneurysm (Video 1). The patient described in this case was a 19-year-old male with a history of polysubstance abuse who presented from an outside hospital after being found unresponsive and admitted for a subarachnoid hemorrhage 7 days earlier. Noninvasive vascular imaging completed at the outside hospital showed no clear intracranial aneurysm except some irregularity of left PICA proximally. The cerebral angiogram subsequently completed after transfer demonstrated a left dissecting PICA aneurysm from the anterior medullary segment of the PICA. Endovascular options were considered to be high risk for this patient due to the wide neck of the aneurysm. Stent coiling was not considered the best option given the concern about recent subarachnoid hemorrhage and the need for antiplatelets. This case is valuable to the literature as it illustrates technical steps required for reconstructing an aneurysm with a dissected wall with pseudoaneurysmal formation, the need for early proximal control, and the use of intraoperative adenosine for temporary cardiac standstill.