Faculty Bibliography

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.

BACKGROUND:Subdural hematoma is a rare manifestation of hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu disease. Here, the authors present a patient with HHT and a large chronic subdural hematoma, for whom nonsurgical management was pursued. OBSERVATIONS/METHODS:A 49-year-old right-handed male with a history of hypertension and familial HHT presented with complaints of mild confusion and left hemiparesis over several days. Noncontrast head computed tomography images demonstrated a large chronic right hemisphere subdural hematoma compressing the right cerebral hemisphere and causing a 1.3-cm midline shift. Due to concerns about surgical complications arising from hemorrhages of cryptic telangiectasias, the patient was treated conservatively with middle meningeal artery embolization and adjuvant tranexamic acid. There was clinical and radiological resolution several months later. LESSONS/CONCLUSIONS:This case highlights the rarity of a subdural hematoma as a manifestation of HHT and the nonsurgical treatment strategy as a mechanism to avoid hemorrhagic complications of surgical evacuation. https://thejns.org/doi/10.3171/CASE24483.

BACKGROUND:Aspiration thrombectomy is one of the mainstays for stroke interventions. The Zoom 71 (Z71) aspiration catheter is unique with its angled tip. This study describes the orientation of the angled tip as it is navigated around the carotid siphon in relation to trackability. METHOD/METHODS:Prospectively collected cases involving large vessel occlusions of the anterior circulation intervened upon using the Z71 were retrospectively analyzed. 71 passes in 50 patients were analyzed with respect to Z71 tip orientation. 3 anatomical "turns" were defined as follows: "1": proximal cavernous, "2"- ophthalmic turn, and "3"-ICA terminus to M1. The tip was described as "Toward" Vs "Away" with respect to the inner curve of each turn. The tip getting "caught" was also analyzed. RESULTS:There was no preferential angled tip orientation of the Z71 as it was navigated around "Turn 1", 51 % "Away" vs 44 % "Toward", p= 0.54; "2", 46.5 % "Away" vs 53.5 % "Toward", p= 0.55; and "3", 43.7 % "Away" vs 46.5 % "Toward", p=0.63. The tip was not caught in Turn 1. It was caught up in "2" in 15.5 % of passes. "Away" at "2" got caught up in 21 % of passes vs 10.5 % for "Toward", p= 0.22. Z71 got caught up in "3" in 4.7 % of passes. "Away" was associated with getting caught in 6.5 % of passes vs 3 % for "Toward", p=0.52. Zoom 88 (Z88) usage as guide catheter may be associated with Z71 getting caught less in "2" compared to "Others", 9.3 % for Z88 vs 25 %, p= 0.07. This also applied to Turn 3, 0 % for Z88 vs 11.1 %, p=0.038. CONCLUSION/CONCLUSIONS:There is no preferential angled tip orientation of the Z71 as it navigates around the carotid siphon. The tip orientation does not appear to significantly affect navigation. Usage of Z88 as guide catheter helps with Z71 trackability around the siphon.

OBJECTIVE:The Woven EndoBridge (WEB) device was approved to treat wide-necked bifurcation aneurysms. The device is designed as an intrasaccular flow disruptor covering aneurysm widths up to 10 mm. Although prior studies combined all aneurysm sizes, it is known that aneurysms behave differently in response to endovascular treatment based on their size. Therefore, the authors' objective was to identify ideal middle cerebral artery (MCA) aneurysm width and neck sizes most suitable for WEB treatment. METHODS:The WorldWideWEB consortium is a large multicenter retrospective database that analyzes intracranial aneurysms treated with the WEB device. In this study, all unruptured MCA bifurcation aneurysms with available measurements were included. Cutoff values based on aneurysm width and neck in relation to aneurysm occlusion status were measured using the receiver operating characteristic (ROC) curve. Propensity score matching (PSM) was then used to compare treatment outcomes between aneurysms smaller and larger than the cutoff value for both width and neck size. RESULTS:The ideal cutoff values for MCA bifurcation aneurysm width and neck were 6.1 mm and 4.6 mm, respectively. On PSM, 87 matched pairs were compared based on width size (≤ 6.1 mm and > 6.1 mm), and 77 matched pairs were compared based on neck size (≤ 4.6 mm and > 4.6 mm). There was a significant difference in adequate aneurysm occlusion between aneurysms smaller and larger than those cutoff values for both widths (93% vs 76%, p = 0.0017) and neck sizes (90% vs 70%, p = 0.0026). The retreatment rate was also significantly higher for larger aneurysms in both parameters. CONCLUSIONS:This study shows that MCA bifurcation aneurysms ≤ 6.1 mm in width and ≤ 4.6 mm in neck size are significantly better candidates for WEB treatment, leading to improved occlusion status and reduced retreatment rate, which are important considerations when using WEB devices.

OBJECTIVE:This study was conducted to investigate the impact of antiplatelet administration in the periprocedural period on the occurrence of thromboembolic complications (TECs) in patients undergoing treatment using the Woven EndoBridge (WEB) device for intracranial wide-necked bifurcation aneurysms. The primary objective was to assess whether the use of antiplatelets in the pre- and postprocedural phases reduces the likelihood of developing TECs, considering various covariates. METHODS:A retrospective multicenter observational study was conducted within the WorldWideWEB Consortium and comprised 38 academic centers with endovascular treatment capabilities. Univariable and multivariable logistic regression analyses were performed to determine the association between antiplatelet use and TECs, adjusting for covariates. Missing predictor data were addressed using multiple imputation. RESULTS:The study comprised two cohorts: one addressing general thromboembolic events and consisting of 1412 patients, among whom 103 experienced TECs, and another focusing on symptomatic thromboembolic events and comprising 1395 patients, of whom 50 experienced symptomatic TECs. Preprocedural antiplatelet use was associated with a reduced likelihood of overall TECs (OR 0.32, 95% CI 0.19-0.53, p < 0.001) and symptomatic TECs (OR 0.49, 95% CI 0.25-0.95, p = 0.036), whereas postprocedural antiplatelet use showed no significant association with TECs. The study also revealed additional predictors of TECs, including stent use (overall: OR 4.96, 95% CI 2.38-10.3, p < 0.001; symptomatic: OR 3.24, 95% CI 1.26-8.36, p = 0.015), WEB single-layer sphere (SLS) type (overall: OR 0.18, 95% CI 0.04-0.74, p = 0.017), and posterior circulation aneurysm location (symptomatic: OR 18.43, 95% CI 1.48-230, p = 0.024). CONCLUSIONS:The findings of this study suggest that the preprocedural administration of antiplatelets is associated with a reduced likelihood of TECs in patients undergoing treatment with the WEB device for wide-necked bifurcation aneurysms. However, postprocedural antiplatelet use did not show a significant impact on TEC occurrence.

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.

Diagnosing and differentiating spinal vascular pathologic conditions is challenging. Small structures, lengthy imaging examinations, and overlapping imaging features increase the difficulty. Yet, subtle findings and helpful protocols can narrow the differential diagnosis. The authors aim to help radiologists make accurate and timely diagnoses of spinal vascular pathologic conditions in and around the spinal cord by highlighting spinal vascular anatomy, imaging findings, and three broad categories of abnormalities: infarcts, anomalies, and tumors. ^©RSNA, 2024.

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.