Faculty Bibliography

BACKGROUND AND IMPORTANCE/BACKGROUND:Rhino-orbital cerebral mucormycosis (ROCM) is an aggressive fungal infection involving the paranasal sinuses, orbit, and intracranial cavity, with a propensity for vascular invasion. This can lead to complications such as internal carotid artery (ICA) thrombosis and occlusion, presenting major neurosurgical challenges. Although surgical debridement and antifungal therapy are the mainstays of treatment, cases with significant neurovascular involvement require specialized intervention. We report a case of ROCM with severe flow-limiting ICA stenosis treated by direct extracranial-intracranial bypass. CLINICAL PRESENTATION/METHODS:tA 65-year-old man with diabetes presented with progressive left-sided blindness and facial numbness. Imaging revealed a left orbital mass extending into the paranasal sinuses and intracranially. Empiric antifungal therapy was started. Pathology confirmed Rhizopus species. Despite extensive surgical debridement and antifungal therapy, the patient developed progressive severe cavernous ICA stenosis, leading to watershed territory strokes. To restore cerebral perfusion, protect from distal emboli, and prepare for potential aggressive debridement, a flow-replacing direct (superficial temporal artery-middle cerebral artery (M2)) bypass was performed, and the supraclinoid carotid was trapped. Intraoperative angiography confirmed robust flow through the bypass. The patient was discharged on antifungal therapy and aspirin. At 6-month follow-up, the patient was neurologically intact with an modified Rankin Scale score of 1. Computed tomography angiography and transcranioplasty Doppler ultrasonography confirmed good flow through the bypass. CONCLUSION/CONCLUSIONS:In addition to antifungal therapy and surgical debridement, superficial temporal artery-middle cerebral artery bypass can be a lifesaving intervention in the management of ROCM with severe cerebrovascular compromise. This case highlights the critical role of cranial bypass in preserving cerebral perfusion in patients with flow-limiting ROCM-associated ICA invasion.

BACKGROUND:Older patients (≥80 years of age) were under-represented in randomized trials of endovascular thrombectomy (EVT). In the large Florida Stroke Registry (FSR), we aimed to evaluate the characteristics of the older patients receiving EVT in routine practice and to study the impact of age on EVT outcomes. METHODS AND RESULTS/RESULTS:Data prospectively collected from Get With The Guidelines-Stroke hospitals in the FSR from January 2010 to December 2022 were analyzed for EVT outcomes. Among patients receiving EVT, characteristics associated with age ≥80 years and the impact of age on EVT outcomes of discharge directly to home or acute inpatient rehabilitation, and independent ambulation at discharge were studied using multivariable analysis with generalized estimating equations. Among 20 004 EVT FSR patients (mean age 71±15, 50% women), 29% were ≥80 years of age. In multivariable analysis, older patients with EVT had a similar rate of symptomatic intracerebral hemorrhage and in hospital mortality but were less likely to achieve independent ambulation at discharge (odds ratio [OR]: 0.44 [95% CI, 0.39-0.49]), be discharged directly home (OR: 0.46 [95% CI, 0.42-0.51]) or to a rehabilitation facility (OR: 0.68 [95% CI, 0.61-0.75]). CONCLUSIONS:In routine practice, close to 30% of EVT treated stroke patients are over the age of 80 years. Our data shows that EVT is safe in this population; however, age remains an independent predictor of poor discharge outcomes post EVT.

Typical carotid webs are nonatherosclerotic shelf-like projections of fibromyxoid tissue extending from the posterior wall of the proximal internal carotid artery (ICA). Carotid webs may precipitate acute embolic stroke, especially in younger patients. We describe our experience with pathology-proven carotid webs of atypical appearance, or atypical carotid webs (ACWs), a subset of carotid webs exhibiting abnormal location, morphology, or association with atherosclerotic changes. Our electronic medical record database was queried for all imaging impressions containing "carotid web," "shelf," or "protrusion" from 2018-2024. Imaging was reviewed by an experienced neuroradiologist and neurosurgeon. Patients with typical carotid webs or those with different diagnoses (e.g. dissection/thrombus) were excluded. Twenty-seven patients were treated for typical carotid webs; 24 were treated with carotid endarterectomy (CEA) and had pathology-confirmed webs. Five patients (three male) were identified to have ACWs and included in this report. Mean age was 43.6 years. All ACWs were identified by computed tomography angiography (CTA). All patients presented with acute ischemic stroke or transient ischemic attack (TIA). One web was located on the anterior ICA wall, three were of abnormal morphology different from a "shelf-like" projection, and one was associated with atherosclerotic change. No patients experienced a further stroke or TIA following CEA. ACWs may precipitate ischemic stroke and can be treated and definitively diagnosed with CEA. Due to their unusual appearance, ACWs may evade radiographic identification or be misdiagnosed. As ACWs have not been previously reported in the literature, awareness of their existence must be raised to increase their detection and treatment.

UNLABELLED:The superior hypophyseal arteries (SHAs) are well known in anatomical and surgical literature, with a well-established role in supply of the anterior hypophysis and superjacent optic apparatus. However, due to small size and overlap with other vessels, in vivo imaging by any modality has been essentially non-existent. Advances in high resolution cone beam CT angiography (CBCTA) now enables this deficiency to be addressed. This paper presents, to the best of our knowledge, the first comprehensive in vivo imaging evaluation of the SHAs. METHODS:Twenty-five CBCTA studies of common or internal carotid arteries were obtained for a variety of clinical reasons. Dedicated secondary reconstructions of the siphon were performed, recording the presence, number, and supply territory of SHAs. A spectrum approach, emphasizing balance with adjacent territories (inferior hypophyseal, ophthalmic, posterior and communicating region arteries) was investigated. RESULTS:The SHAs were present in all cases. Supply of the anterior pituitary was nearly universal (96%) and almost half (44%) originated from the 'cave' region, in excellent agreement with surgical literature. Optic apparatus supply was more difficult to adjudicate, but appeared present in most cases. The relationship with superior hypophyseal aneurysms was consistent. Patency following flow diverter placement was typical, despite a presumably rich collateral network. Embryologic implications with respect to the ophthalmic artery and infraoptic course of the anterior cerebral artery are intriguing. CONCLUSIONS:SHAs are consistently seen with CBCTA, allowing for correlation with existing anatomical and surgical literature, laying the groundwork for future in vivo investigation.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Superficial temporal artery to middle cerebral artery (STA-MCA) bypass is the workhorse for flow augmentation surgery. Although either interrupted or running sutures can be used to complete the anastomosis with high intraoperative patency rates, no previous study in the cranial bypass literature has compared long-term patency and maturity of end-to-side STA-MCA anastomoses. We compared STA-MCA anastomoses performed with running vs interrupted sutures by evaluating bypass flow and anastomotic maturation on follow-up vascular imaging. METHODS:Ninety-six STA-MCA anastomoses were performed from 1/2019 to 6/2024. Forty-seven anastomoses (40 patients) with long-term vascular imaging were retrospectively analyzed. All anastomoses were intraoperatively patent on initial revascularization. Patient demographics, clinical course, and imaging were reviewed. All images were reviewed by a neuroradiologist or a cerebrovascular neurosurgeon. RESULTS:Twenty-five anastomoses were performed with interrupted sutures and compared with 22 anastomoses performed with running sutures. All patients underwent a preoperative perfusion assessment confirming a significant hypoperfusion state. There were no significant differences between cohorts in demographics, bypass indication, or time to follow-up. Formal digital subtraction angiography was performed for 35 anastomoses (21 interrupted, 14 running). On digital subtraction angiography follow-up, there was no difference in STA caliber between cohorts (P = .204), but there was a difference in anastomotic growth (P = .014), with 5/21 (23.8%) anastomoses stable or enlarged in the interrupted cohort vs 9/14 (64.3%) stable or enlarged in the running cohort. Notably, of the 47 total anastomoses, there was no difference in long-term bypass patency between interrupted and running anastomoses (22/25 (88.0%) vs 22/22 (100.0%), respectively, P = .380). CONCLUSION/CONCLUSIONS:No significant differences in patency or STA caliber on follow-up imaging were observed between STA-MCA anastomoses performed with interrupted vs running sutures although a difference in anastomotic maturity was observed, with the running suture cohort having a higher proportion of enlarged or stable anastomoses. Further studies are needed for validation.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Robotics are becoming increasingly widespread within various neurosurgical subspecialties, but data pertaining to their feasibility in vascular neurosurgery are limited. We present our novel attempt to evaluate the learning curve of a robotic platform for microvascular anastomoses. METHODS:One hundred and sixty one sutures were performed and assessed. Fourteen anastomoses (10 robotic [MUSA-2 Microsurgical system; Microsure] and 4 hand-sewn) were performed by the senior author on 1.5-mm caliber tubes and recorded with the Kinevo 900 (Zeiss) operative microscope. We separately compared interrupted sutures (from needle insertion until third knot) and running sutures (from needle insertion until loop pull-down). Average suture timing across all groups was compared using an unpaired Student's t test. Exponential smoothing (α = 0.2) was then applied to the robotic data sets for validation and a second set of t tests were performed. RESULTS:We compared 107 robotic sutures with 54 hand-sewn sutures. There was a significant difference between the average time/stitch for the robotic running sutures (n = 55) and the hand-sewn running sutures (n = 31) (31.2 seconds vs 48.3 seconds, respectively; P-value = .00052). Exponential smoothing (α = 0.2) reinforced these results (37.6 seconds vs 48.3 seconds; P-value = .014625). Average robotic running times surpassed hand-sewn by the second anastomosis (38.8 seconds vs 48.3 seconds) and continued to steadily decrease with subsequent stitches. The average of the robotic interrupted sutures (n = 52) was significantly longer than the hand-sewn (n = 23) (171.3 seconds vs 70 seconds; P = .000024). Exponential smoothing (α = 0.2) yielded similar results (196.7 seconds vs 70 seconds; P = .00001). However, average robotic interrupted times significantly decreased from the first to the final anastomosis (286 seconds vs 105.2 seconds; P = .003674). CONCLUSION/CONCLUSIONS:Our results indicate the learning curve for robotic microanastomoses is short and encouraging. The use of robotics warrants further study for potential use in cerebrovascular bypass procedures.

BACKGROUND:Hypoglossal canal dural arteriovenous fistulas (HCDAVFs) are a relatively rare subtype of dural arteriovenous fistula (dAVF), representing 3%-5% of all dAVFs. The complex angio- and venous architecture predisposed to numerous anastomoses and nearby anatomical structures, including the posterior fossa sinuses and cranial nerves, can complicate both the diagnosis and treatment of these lesions. OBSERVATIONS/METHODS:The authors describe the case of HCDAVF in a 74-year-old male who presented with pulsatile tinnitus (PT) lasting 3 months and significant fatigue, headaches, and dizziness. Diagnostic cerebral angiography demonstrated a left-sided HCDAVF with bilateral supply from the ascending pharyngeal arteries and fistulous connection at the level of the left anterior condylar vein (ACV). This lesion was consistent with a Cognard and Borden type I dAVF. LESSONS/CONCLUSIONS:The authors present a case in which transvenous embolization (TVE) with detachable coils via the ipsilateral internal jugular vein successfully occluded the previously visualized shunt to the left ACV and provided a clinical cure for the patient's PT and headaches without complication. Selecting the appropriate treatment strategy for the successful treatment of HCDAVFs is predicated on a comprehensive understanding of the anatomical features of the lesion, namely arterial feeders, venous drainage pattern, and location of the fistulous connection. TVE is a safe and efficacious treatment option for HCDAVFs. https://thejns.org/doi/10.3171/CASE24606.

Dural arteriovenous fistulas (dAVFs) can occur as complications after surgical procedures, especially following the resection of meningiomas near the dural sinus. This case report presents a 74-year-old male who developed a recurrent sigmoid dAVF following meningioma resection. Initially treated with transvenous embolization and middle meningeal artery embolization, the dAVF recurred with worsening clinical symptoms. Conventional treatment options, including sinus sacrifice and transarterial embolization, were unsuitable due to the critical role of the patient's dominant right sigmoid sinus in cerebral venous drainage. Consequently, a reconstructive approach was employed using a pipeline embolization device (PED) construct. The PED successfully occluded the dAVF while preserving the function of the sigmoid sinus. A follow-up angiogram confirmed stable occlusion and normalization of intracranial venous drainage. This case underscores the potential of flow diversion as a viable treatment option for dAVFs, particularly in scenarios where preserving venous sinus function is paramount.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Inherent complex angioarchitecture associated with ethmoidal dural arteriovenous fistulas (dAVFs) can make endovascular treatment methods challenging. Many surgical approaches are accompanied by unfavorable cosmetic results such as facial scarring. Blepharoplasty incision of the eyelid offers a minimal, well-hidden scar compared with other incision sites while offering the surgeon optimal visualization of pathogenic structures. This case series aims to report an initial assessment of the safety and efficacy of supraorbital craniotomy by blepharoplasty transpalpebral (eyelid) incision for surgical disconnection of ethmoidal dAVFs. METHODS:Retrospective chart review was conducted for all patients who underwent blepharoplasty incision and craniotomy for disconnection of ethmoidal dAVFs at our institution between October 2011 and February 2023. Patient charts and follow-up imaging were reviewed to report clinical and angiographic outcomes as well as periprocedural and follow-up complications. RESULTS:Complete obliteration and disconnection of ethmoidal dAVF was achieved in all 6 (100%) patients as confirmed by intraoperative angiogram with no resulting morbidity or mortality. Periprocedural complications included one case of transient nasal cerebrospinal fluid leak that was self-limiting and resolved before discharge without intervention. CONCLUSION/CONCLUSIONS:Surgical treatment for ethmoidal dAVFs, specifically by transpalpebral incision and supraorbital craniotomy, is a safe and effective treatment option and affords the surgeon greater access to the floor of the anterior fossa when necessary. In addition, blepharoplasty incision addressed patient concerns for facial scarring compared with other incision sites by creating a more well-hidden, minimal scar in the natural folds of the eyelid for patients with an eyelid crease.

OBJECTIVE:The objective of this study was to investigate the use of indocyanine green videoangiography with FLOW 800 hemodynamic parameters intraoperatively during superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery to predict patency prior to anastomosis performance. METHODS:A retrospective and exploratory data analysis was conducted using FLOW 800 software prior to anastomosis to assess four regions of interest (ROIs; proximal and distal recipients and adjacent and remote gyri) for four hemodynamic parameters (speed, delay, rise time, and time to peak). Medical records were used to classify patients into flow and no-flow groups based on immediate or perioperative anastomosis patency. Hemodynamic parameters were compared using univariate and multivariate analyses. Principal component analysis was used to identify high risk of no flow (HRnf) and low risk of no flow (LRnf) groups, correlated with prospective angiographic follow-ups. Machine learning models were fitted to predict patency using FLOW 800 features, and the a posteriori effect of complication risk of those features was computed. RESULTS:A total of 39 cases underwent STA-MCA bypass surgery with complete FLOW 800 data collection. Thirty-five cases demonstrated flow after anastomosis revascularization and were compared with 4 cases with no flow after revascularization. Proximal and distal recipient speeds were significantly different between the no-flow and flow groups (proximal: 238.3 ± 120.8 and 138.5 ± 93.6, respectively [p < 0.001]; distal: 241.0 ± 117.0 and 142.1 ± 103.8, respectively [p < 0.05]). Based on principal component analysis, the HRnf group (n = 10) was characterized by high-flow speed (> 75th percentile) in all ROIs, whereas the LRnf group (n = 10) had contrasting patterns. In prospective long-term follow-up, 6 of 9 cases in the HRnf group, including the original no-flow cases, had no or low flow, whereas 8 of 8 cases in the LRnf group maintained robust flow. Machine learning models predicted patency failure with a mean F1 score of 0.930 and consistently relied on proximal recipient speed as the most important feature. Computation of posterior likelihood showed a 95.29% chance of patients having long-term patency given a lower proximal speed. CONCLUSIONS:These results suggest that a high proximal speed measured in the recipient vessel prior to anastomosis can elevate the risk of perioperative no flow and long-term reduction of flow. With an increased dataset size, continued FLOW 800-based ROI metric analysis could be used to guide intraoperative anastomosis site selection prior to anastomosis and predict patency outcome.