Treatment of pediatric intracranial aneurysms: institutional case series and systematic literature review.

INTRODUCTION: Pediatric intracranial aneurysms (IAs) are rare and have distinct clinical profiles compared to adult IAs. They differ in location, size, morphology, presentation, and treatment strategies. We present our experience with pediatric IAs over an 18-year period using surgical and endovascular treatments and review the literature to identify commonalities in epidemiology, treatment, and outcomes. METHODS: We identified all patients < 20 years old who underwent treatment for IAs at our institution between 2005 and 2020. Medical records and imaging were examined for demographic, clinical, and operative data. A systematic review was performed to identify studies reporting primary outcomes of surgical and endovascular treatment of pediatric IAs. Demographic information, aneurysm characteristics, treatment strategies, and outcomes were collected. RESULTS: Thirty-three patients underwent treatment for 37 aneurysms over 18 years. The mean age was 11.4 years, ranging from one month to 19 years. There were 21 males (63.6%) and 12 females (36.4%), yielding a male: female ratio of 1.75:1. Twenty-six (70.3%) aneurysms arose from the anterior circulation and 11 (29.7%) arose from the posterior circulation. Aneurysmal rupture occurred in 19 (57.5%) patients, of which 8 (24.2%) were categorized as Hunt-Hess grades IV or V. Aneurysm recurrence or rerupture occurred in five (15.2%) patients, and 5 patients (15.2%) died due to sequelae of their aneurysms. Twenty-one patients (63.6%) had a good outcome (modified Rankin Scale score 0-2) on last follow up. The systematic literature review yielded 48 studies which included 1,482 total aneurysms (611 with endovascular treatment; 656 treated surgically; 215 treated conservatively). Mean aneurysm recurrence rates in the literature were 12.7% and 3.9% for endovascular and surgical treatment, respectively. CONCLUSIONS: Our study provides data on the natural history and longitudinal outcomes for children treated for IAs at a single institution, in addition to our treatment strategies for various aneurysmal morphologies. Despite the high proportion of patients presenting with rupture, good functional outcomes can be achieved for most patients.

Optimizing suction force in mechanical thrombectomy: Priming the aspiration tubing with air versus saline.

Objective: We sought to investigate how priming the tube between air versus air mixed with saline ex vivo influenced suction force. We examined how priming the tube influenced peak suction force and time to achieve peak suction force between both modalities. Methods: Using a Dwyer Instruments (Dwyer Instruments Inc., Michigan City, IN, USA), INC Digitial Pressure Gauge, we were able to connect a .072 inch aspiration catheter to a rotating hemostatic valve and to aspiration tubing. We recorded suction force measured in negative inches of Mercury (inHg) over 10 iterations between having the aspiration tube primed with air alone versus air mixed with saline. A test was used to compare results between both modalities. Results: Priming the tube with air alone compared to air mixed with saline was found to have an increased average max suction force (-28.60 versus -28.20 in HG, p<0.01). We also identified a logarithmic curve of suction force across time in which time to maximal suction force was more prompt with air compared with air mixed with saline (13.8 seconds versus 21.60 seconds, p<0.01). Conclusions: Priming the tube with air compared to air mixed with saline suggests that not only is increased maximal suction force achieved, but also the time required to achieve maximal suction force is less. This data suggests against priming the aspiration tubing with saline and suggests that the first pass aspiration primed with air may have the greatest suction force.

Identification and management of low-risk isolated traumatic brain injury patients initially treated at a rural level IV trauma center.

STUDY OBJECTIVE: Our goal was to determine if low-risk, isolated mild traumatic brain injury (TBI) patients who were initially treated at a rural emergency department may have been safely managed without transfer to the tertiary referral trauma center. METHODS: This was a retrospective observational analysis of isolated mild TBI patients who were transferred from a rural Level IV Trauma Center to a regional Level I Trauma Center between 2018 and 2022. Patients were risk-stratified according to the modified Brain Injury Guidelines (mBIG). Data abstracted from the electronic medical record included patient presentation, management, and outcomes. RESULTS: 250 patients with isolated mild TBI were transferred out to the Level I Trauma Center. Fall was the most common mechanism of injury (69.2%). 28 patients (11.2%) were categorized as low-risk (mBIG1). No mBIG1 patients suffered a progression of neurological injury, had worsening of intracranial hemorrhage on repeat head CT, or required neurosurgical intervention. 12/28 (42.9%) of mBIG1 patients had a hospital length of stay of 2 days or less, typically for observation. Those with longer lengths of stay were due to medical complications, such as sepsis, or difficulty in arranging disposition. CONCLUSION: We propose that patients who meet mBIG1 criteria may be safely observed without transfer to a referral Level I Trauma Center. This would be of considerable benefit to patients, who would not need to leave their community, and would improve resource utilization in the region.

Reducing frame rate and pulse rate for routine diagnostic cerebral angiography: ALARA principles in practice.

OBJECTIVE: Diagnostic cerebral angiograms (DCAs) are widely used in neurosurgery due to their high sensitivity and specificity to diagnose and characterize pathology using ionizing radiation. Eliminating unnecessary radiation is critical to reduce risk to patients, providers, and health care staff. We investigated if reducing pulse and frame rates during routine DCAs would decrease radiation burden without compromising image quality. METHODS: We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. Radiation doses and exposures were calculated. Two endovascular neurosurgeons reviewed randomly selected angiograms of both doses and blindly assessed their quality. RESULTS: A total of 40 consecutive angiograms were retrospectively analyzed, 20 prior to the protocol change and 20 after. After the intervention, radiation dose, radiation per run, total exposure, and exposure per run were all significantly decreased even after adjustment for BMI (all p<0.05). On multivariable analysis, we identified a 46% decrease in total radiation dose and 39% decrease in exposure without compromising image quality or procedure time. CONCLUSIONS: We demonstrated that for routine DCAs, pulse rate of 7.5 with a frame rate of 4.0 is sufficient to obtain diagnostic information without compromising image quality or elongating procedure time. In the interest of patient, provider, and health care staff safety, we strongly encourage all interventionalists to be cognizant of radiation usage to avoid unnecessary radiation exposure and consequential health risks.

The Cost of Operating: Analysis of Single-Use Instrument Costs for Craniotomies.

Introduction All-cause craniotomies comprise a significant portion of neurosurgical practice as well as hospital costs. While some instruments are reusable with a fixed cost, price variability for similar single-use instruments exists. A better understanding of these cost variations within cranial procedures can better inform operating physicians to be cost-sensitive stewards. Objective In this study, we examine how single-use items contribute to the overall cost of cranial procedures.  Methods A de-identified institutional database containing records of all single-use items from craniotomies between July 1, 2019, and June 30, 2020, was subject to a longitudinal analysis by three independent parties (one senior surgeon, one resident, and one medical student). Four hundred and sixty-nine unique single-use items were identified and classified by function. Similar items were combined, and a range of costs was provided. Three sample cases with sum costs were reviewed for cost division and primary contributors. Results  The category with the highest median cost across all cases was non-specialty implants comprising dural onlays, mesh, aneurysm clips, and plates. The category with the lowest median cost was personal protective equipment. The items with the most cost variability were sterile surgical patties due to the variety of sizes and preset multipacks. The proportion of cost generators varies from craniotomy indication.  Conclusion While institution dependent, awareness of cost generators in cranial cases is important for economic stewardship. For single-use items, costs are highly variable and not insignificant. Surgeons and neurosurgical departments are responsible for allocating single-use items in a responsible and efficient manner.

Custom 3D-Printed External Cranial Orthotic for Prevention and Treatment of Syndrome of the Trephined.

Syndrome of the Trephined (SoT) is a frequently misunderstood and underdiagnosed outcome of decompressive craniectomy, especially in cases of trauma. The pressure gradient between atmospheric pressure and the sub-atmospheric intracranial pressure results in a sinking of the scalp overlying the craniectomy site. This gradually compresses the underlying brain parenchyma. This parenchymal compression can disrupt normal autoregulation and subsequent metabolism, yielding symptoms ranging from headaches, dizziness, altered behavior to changes in sensation, and difficulty with ambulation, coordination, and activities of daily living. We present a case of SoT treated with a 3D-printed custom polycarbonate external cranial orthotic that allowed us to re-establish this pressure gradient by returning the cranium to a closed system. The patient demonstrated subjective improvement in quality of life and his symptoms. This was consistent with the re-expanded brain parenchyma on CT imaging.

Safety of middle meningeal artery embolization for treatment of subdural hematoma: A nationwide propensity score matched analysis.

OBJECTIVE: Middle meningeal artery embolization (MMAe) has burgeoned as a treatment for chronic subdural hematoma (cSDH). This study evaluates the safety and short-term outcomes of MMAe patients relative to traditional treatment approaches. METHODS: In this retrospective large database study, adult patients in the National Inpatient Sample from 2012-2019 with a diagnosis of cSDH were identified. Cost of admission, length of stay (LOS), discharge disposition, and complications were analyzed. Propensity score matching (PSM) was utilized. RESULTS: A total of 123,350 patients with cSDH were identified: 63,450 without intervention, 59,435 surgery only, 295 MMAe only, and 170 surgery plus MMAe. On PSM analysis, MMAe did not increase the risk of inpatient complications or prolong the length of stay compared to conservative management (p>0.05); MMAe had higher cost ($31,170 vs. $10,768, p<0.001) than conservative management, and a lower rate of nonroutine discharge (53.8% vs. 64.3%, p=0.024). Compared to surgery, MMAe had shorter LOS (5 vs. 7 days, p<0.001), and lower rates of neurological complications (2.7% vs. 7.1%, p=0.029) and nonroutine discharge (53.8% vs. 71.7%, p<0.001). There was no significant difference in cost (p>0.05). CONCLUSIONS: MMAe had similar LOS and decreased odds of adverse discharge with a modest cost increase compared to conservative management. There was no difference in inpatient complications. Compared to surgery, MMAe treatment was associated with decreased LOS and rates of neurological complications and nonroutine discharge. This nationwide analysis supports the safety of MMAe to treat cSDH.

Direct Transorbital Approach for Treatment of Carotid Cavernous Fistula: An Illustrative Case Series.

BACKGROUND AND OBJECTIVES: Endovascular techniques have become the first-line treatment for carotid-cavernous fistulas (CCFs). Direct transorbital venous access may be used if anatomic constraints limit standard transarterial or transvenous access. We describe our institutional experience with the transorbital approach for Barrow Type A-D CCFs. METHODS: Patients with CCFs undergoing transorbital endovascular treatment at our institution between 2017 and 2019 were retrospectively reviewed. Demographic, treatment, and outcome data were collected. RESULTS: Eight patients met inclusion criteria, 4 female and 4 male patients. The mean age was 43 years, with 6 right-sided CCF and 2 left-sided CCFs. Symptoms were present for an average of 1.5 months before treatment. All patients presented with eye pain and subjective visual changes. Seven (87.5%) patients presented with proptosis, 6 (75%) patients had elevated intraocular pressure (IOP), and 3 (37.5%) patients had ophthalmoplegia. Six CCFs (75%) were spontaneous, and 2 CCFs (25%) were traumatic. Barrow types were A (n = 1), B (n = 1), C (n = 1), and D (n = 5). All patients underwent direct percutaneous transorbital embolization with coils followed by Onyx. Three patients had undergone prior transarterial and/or transvenous treatment. A radiographic cure was obtained in all patients after direct transorbital embolization. After CCF cure, cranial nerve palsies resolved in 66.7% of patients, visual acuity in the affected eye was improved or stable in 75% of patients, and IOP had normalized in 85.7% of patients. Proptosis improved in all patients, with complete resolution in 75%. CONCLUSION: Direct transorbital embolization is a safe and potentially curative treatment for all 4 Barrow types of CCFs.

Histology of the Porous Oculomotorius: Relevance to Anterior Skull Base Approaches.

Objective Mobilization of cranial nerve III (CNIII) at its dural entry site is commonly described to avoid damage from stretching during approaches to the parasellar, infrachiasmatic, posterior clinoid, and cavernous sinus regions. The histologic relationships of CNIII as it traverses the dura, and the associated surgical implications are nonetheless poorly described. We herein assess the histology of the CNIII-dura interface as it relates to surgical mobilization of the nerve. Methods A fronto-orbitozygomatic temporopolar approach was performed on six adult cadaveric specimens. The CNIII-dural entry site was resected and histologically processed. The nerve-tissue planes were assessed by a neuropathologist. Results Histologic analysis demonstrated that CNIII remained separate from the dura within the oculomotor cistern (porous oculomotorius up to the oculomotor foramen). Fusion of the epineurium of CNIII and the connective tissue of the dura was seen at the level of the foramen, with no clear histologic plane identified between these structures. Conclusion CNIII may be directly mobilized within the oculomotor cistern, while dissections of CNIII distal to the oculomotor foramen should maintain a thin layer of connective tissue on the nerve.

Enlarging symptomatic arachnoid cyst in an elderly patient: illustrative case.

BACKGROUND: Arachnoid cysts are congenital or acquired structures found within the brain and are rarely symptomatic for adults. The literature documenting enlarging arachnoid cysts in adults is also discussed. OBSERVATIONS: An elderly woman presented with acutely worsening headaches, photophobia, cognitive function, and a seizure-like episode. The patient had a known arachnoid cyst with a decade of radiographic stability, which was now idiopathically enlarging. The patient had a previous history of traumatic brain injuries but no reported trauma around the time of presentation. Due to the severity of midline shift and symptomatology, the decision was made to treat the patient surgically with fenestration and shunting. She recovered well postoperatively. LESSONS: During the workup for a symptomatic elderly patient, enlargement of a previously asymptomatic arachnoid cyst should remain on the differential until specifically ruled out, even in the absence of recent trauma. While rare, enlarging arachnoid cysts result in neurological findings and impact the quality of life for patients.

Complementary Tools in Cerebral Bypass Surgery.

Cerebral revascularization surgery has been advanced by the refinement of several adjunctive tools. These tools include perioperative blood thinners, intraoperative spasmolytic agents, electrophysiological monitoring, and methods for assessing bypass patency or marking arteriotomies. Despite the array of options, the proper usage and comparative advantages of different complements in cerebral bypass have not been well-cataloged elsewhere. In this literature review, we describe the appropriate usage, benefits, and limitations of various bypass adjuncts. Understanding these adjuncts can help surgeons ensure that they receive reliable intraoperative information about bypass function and minimize the risk of serious complications. Overall, this review provides a succinct reference for neurosurgeons on various cerebrovascular bypass adjuncts.

Robotics and Artificial Intelligence in Endovascular Neurosurgery.

The use of artificial intelligence (AI) and robotics in endovascular neurosurgery promises to transform neurovascular care. We present a review of the recently published neurosurgical literature on artificial intelligence and robotics in endovascular neurosurgery to provide insights into the current advances and applications of this technology. The PubMed database was searched for "neurosurgery" OR "endovascular" OR "interventional" AND "robotics" OR "artificial intelligence" between January 2016 and August 2021. A total of 1296 articles were identified, and after applying the inclusion and exclusion criteria, 38 manuscripts were selected for review and analysis. These manuscripts were divided into four categories: 1) robotics and AI for the diagnosis of cerebrovascular pathology, 2) robotics and AI for the treatment of cerebrovascular pathology, 3) robotics and AI for training in neuroendovascular procedures, and 4) robotics and AI for clinical outcome optimization. The 38 articles presented include 23 articles on AI-based diagnosis of cerebrovascular disease, 10 articles on AI-based treatment of cerebrovascular disease, two articles on AI-based training techniques for neuroendovascular procedures, and three articles reporting AI prediction models of clinical outcomes in vascular disorders of the brain. Innovation with robotics and AI focus on diagnostic efficiency, optimizing treatment and interventional procedures, improving physician procedural performance, and predicting clinical outcomes with the use of artificial intelligence and robotics. Experimental studies with robotic systems have demonstrated safety and efficacy in treating cerebrovascular disorders, and novel microcatheterization techniques may permit access to deeper brain regions. Other studies show that pre-procedural simulations increase overall physician performance. Artificial intelligence also shows superiority over existing statistical tools in predicting clinical outcomes. The recent advances and current usage of robotics and AI in the endovascular neurosurgery field suggest that the collaboration between physicians and machines has a bright future for the improvement of patient care. The aim of this work is to equip the medical readership, in particular the neurosurgical specialty, with tools to better understand and apply findings from research on artificial intelligence and robotics in endovascular neurosurgery.

Maturation of the sella turcica and parasellar region: Surgical relevance for anterior skull base approaches in pediatric patients.

OBJECTIVE: Traditional and extended transnasal transsphenoidal approaches provide direct access to a variety of anterior skull base pathologies. Despite increased utilization of transnasal approaches in children, anatomic studies on pediatric skull base maturation are limited. We herein perform a surgically relevant morphometric analysis of the sella and parasellar regions during pediatric maturation. METHODS: Measurements of sellar length (SL), sellar depth (SDp), sellar diameter (SDm), interclinoid distance (ID), intercavernous distance (ICD), and the presence of sphenoid sinus pneumatization (SSP), and sphenoid sinus type (SST) were made on thin-cut CT scans from 60 patients (evenly grouped by ages 0-3, 4-7, 8-11 12-15, 16-18, and >18 years) for analysis. Data were analyzed by sex and age groups using t-tests and linear regression. RESULTS: Sella and parasellar parameters did not differ by sex. SL steadily increased from 8.5 ± 1.2 mm to 11.5 ± 1.6 mm throughout development. SDp and SDm increased from 6.0 ± 0.9 mm to 9.3 ± 1.4 mm and 9.0 ± 1.6 mm to 14.4 ± 1.8 mm during maturation, with significant interval growth from ages 16-18 to adult (p < 0.01). ID displayed significant growth from ages 0-3 to 4-7 (18.0 ± 2.4 mm to 20.7 ± 1.9 mm; p = 0.002) and ICD from ages 0-3 to 8-11 (12.0 ± 1.8 mm to 13.5 ± 2.1 mm; p < 0.001), without further significant interval growth. SSP was not seen in patients < 3, but was 100% by ages 8-11. SSTs progressed from conchal/presellar (60% at ages 4-7) to sellar/postsellar (80% at adulthood). CONCLUSION: The sella and parasellar regions have varied growth patterns with development. Knowledge of the expected maturation of key anterior skull base structures may augment surgical planning in younger patients.

Maturation of the internal auditory canal and posterior petrous bone with relevance to lateral and posterolateral skull base approaches.

Anatomic knowledge of the internal auditory canal (IAC) and surrounding structures is a prerequisite for performing skull base approaches to the IAC. We herein perform a morphometric analysis of the IAC and surgically relevant aspects of the posterior petrous bone during pediatric maturation, a region well-studied in adults but not children. Measurements of IAC length (IAC-L), porus (IAC-D) and midpoint (IAC-DM) diameter, and distance from the porus to the common crus (CC; P-CC) and posterior petrosal surface (PPS) to the posterior semicircular canal (PSC; PPS-PSC) were made on thin-cut axial CT scans from 60 patients (grouped by ages 0-3, 4-7, 8-11 12-15, 16-18, and > 18 years). IAC-L increased 27.5% from 8.7 ± 1.1 at age 0-3 to 11.1 ± 1.1 mm at adulthood (p = 0.001), with the majority of growth occurring by ages 8-11. IAC-D (p = 0.52) and IAC-DM (p = 0.167) did not significantly change from ages 0-3 to adult. P-CC increased 31.1% from 7.7 ± 1.5 at age 0-3 to 10.1 ± 1.5 mm at adulthood (p = 0.019). PPS-PSC increased 160% from 1.5 ± 0.7 at age 0-3 to 3.9 ± 1.2 mm at adulthood (p < 0.001). The majority of growth in P-CC and PPS-PSC occurred by ages 12-15. Knowledge of these patterns may facilitate safe exposure of the IAC in children.

Microsurgical Resection of a Giant Posterior Fossa Aneurysmal Malformation in a 21-Month-Old.

Pediatric aneurysms commonly occur in the vertebrobasilar circulation with complex morphologies.1 "Aneurysmal malformations," or fistulous vessel dilations without a nidus, have also been described.2 Vessel friability and sensitivity to blood loss can complicate surgery. A 21-month-old male with motor and speech delay was found to have a giant posterior fossa aneurysmal malformation. He was lethargic, with minimal speech, and moved all extremities with mild hypotonia. Imaging demonstrated a 6.9 × 5.1 × 4.6 cm aneurysm arising from a fenestrated right V4 segment. This communicated via a single connection with the deep venous system, draining through the superior vermian cistern veins, posterior mesencephalic vein, basal vein of Galen, and inferior sagittal sinus, consistent with an arteriovenous fistula with secondary aneurysmal dilatation. Endovascular sacrifice was not feasible, in addition to concern for swelling after embolization. Three-dimensional modeling confirmed close proximity of the single inflow and outflow tracts. A suboccipital and left far lateral craniotomy for clip trapping and excision of the aneurysmal arteriovenous malformation was performed in a lateral position to completely decompress the brainstem (Video 1). Angiography before closure and postoperative vascular imaging demonstrated complete aneurysmal resection and fistula disconnection, with patency of normal vasculature. The postoperative course was notable for transient swallowing difficulties likely from lower cranial nerve irritation and refractory hydrocephalus requiring a shunt. The patient was meeting all developmental milestones at 2-year follow-up. This case highlights the complex vascular pathology often seen in pediatric patients, as well as the importance of presurgical planning and careful microsurgical technique in achieving a successful outcome.

Maturation of the anterior petrous apex: surgical relevance for performance of the middle fossa transpetrosal approach in pediatric patients.

OBJECTIVE: The middle fossa transpetrosal approach to the petroclival and posterior cavernous sinus regions includes removal of the anterior petrous apex (APA), an area well studied in adults but not in children. To this end, the authors performed a morphometric analysis of the APA region during pediatric maturation. METHODS: Measurements of the distance from the clivus to the internal auditory canal (IAC; C-IAC), the distance of the petrous segment of the internal carotid artery (petrous carotid; PC) to the mesial petrous bone (MPB; PC-MPB), the distance of the PC to the mesial petrous apex (MPA; PC-MPA), and the IAC depth from the middle fossa floor (IAC-D) were made on thin-cut CT scans from 60 patients (distributed across ages 0-3, 4-7, 8-11, 12-15, 16-18, and > 18 years). The APA volume was calculated as a cylinder using C-IAC (length) and PC-MPB (diameter). APA pneumatization was noted. Data were analyzed by laterality, sex, and age. RESULTS: APA parameters did not differ by laterality or sex. APA pneumatization was seen on 20 of 60 scans (33.3%) in patients ≥ 4 years. The majority of the APA region growth occurred by ages 8-11 years, with PC-MPA and PC-MPB increasing 15.9% (from 9.4 to 10.9 mm, p = 0.08) and 23.5% (from 8.9 to 11.0 mm, p < 0.01) between ages 0-3 and 8-11 years, and C-IAC increasing 20.7% (from 13.0 to 15.7 mm, p < 0.01) between ages 0-3 and 4-7 years. APA volume increased 79.6% from ages 0-3 to 8-11 years (from 834.3 to 1499.2 mm3, p < 0.01). None of these parameters displayed further significant growth. Finally, IAC-D increased 51.1% (from 4.3 to 6.5 mm, p < 0.01) between ages 0-3 and adult, without significant differences between successive age groups. CONCLUSIONS: APA development is largely complete by the ages of 8-11 years. Knowledge of APA growth patterns may aid approach selection and APA removal in pediatric patients.

Surgical revascularization for Moyamoya disease in the United States: A cost-effectiveness analysis.

OBJECTIVE: Moyamoya disease (MMD) is a vasculopathy of the internal carotid arteries with ischemic and hemorrhagic sequelae. Surgical revascularization confers upfront peri-procedural risk and costs in exchange for long-term protective benefit against hemorrhagic disease. The authors present a cost-effectiveness analysis (CEA) of surgical versus non-surgical management of MMD. METHODS: A Markov Model was used to simulate a 41-year-old suffering a transient ischemic attack (TIA) secondary to MMD and now faced with operative versus nonoperative treatment options. Health utilities, costs, and outcome probabilities were obtained from the CEA registry and the published literature. The primary outcome was incremental cost-effectiveness ratio which compared the quality adjusted life years (QALYs) and costs of surgical and nonsurgical treatments. Base-case, one-way sensitivity, two-way sensitivity, and probabilistic sensitivity analyses were performed with a willingness to pay threshold of $50,000. RESULTS: The base case model yielded 3.81 QALYs with a cost of $99,500 for surgery, and 3.76 QALYs with a cost of $106,500 for nonsurgical management. One-way sensitivity analysis demonstrated the greatest sensitivity in assumptions to cost of surgery and cost of admission for hemorrhagic stroke, and probabilities of stroke with no surgery, stroke after surgery, poor surgical outcome, and death after surgery. Probabilistic sensitivity analyses demonstrated that surgical revascularization was the cost-effective strategy in over 87.4% of simulations. CONCLUSIONS: Considering both direct and indirect costs and the postoperative QALY, surgery is considerably more cost-effective than non-surgical management for adults with MMD.

Arteriovenous malformation surgery in children: the Rady Children's Hospital experience (2002-2019).

PURPOSE: Compared to adult AVMs, there is a paucity of data on the microsurgical treatment of pediatric AVMs. We report our institutional experience with pediatric AVMs treated by microsurgical resection with or without endovascular embolization and radiation therapy. METHODS: We retrospectively reviewed all patients ≤ 18 years of age with cerebral AVMs that underwent microsurgical resection at Rady Children's Hospital 2002-2019. RESULTS: Eighty-nine patients met inclusion criteria. The mean age was 10.3 ± 5.0 years, and 56% of patients were male. In total, 72 (81%) patients presented with rupture. Patients with unruptured AVMs presented with headache (n = 5, 29.4%), seizure (n = 9, 52.9%), or incidental finding (n = 3, 17.7%). The mean presenting mRS was 2.8 ± 1.8. AVM location was lobar in 78%, cerebellar/brainstem in 15%, and deep supratentorial in 8%. Spetzler-Martin grade was I in 28%, II in 45%, III in 20%, IV in 6%, and V in 1%. Preoperative embolization was utilized in 38% of patients and more frequently in unruptured than ruptured AVMs (62% vs. 32%, p = 0.022). Radiographic obliteration was achieved in 76/89 (85.4%) patients. Complications occurred in 7 (8%) patients. Annualized rates of delayed rebleeding and recurrence were 1.2% and 0.9%, respectively. The mean follow-up was 2.8 ± 3.1 years. A good neurological outcome (mRS score ≤ 2) was obtained in 80.9% of patients at last follow-up and was improved relative to presentation for 75% of patients. CONCLUSIONS: Our case series demonstrates high rates of radiographic obliteration and relatively low incidence of neurologic complications of treatment or AVM recurrence.

Site of Occlusion May Influence Decision to Perform Thrombectomy Under General Anesthesia or Conscious Sedation.

BACKGROUND: Although mechanical thrombectomy has become the standard of care for large-vessel occlusion, the role of conscious sedation versus general anesthesia (GA) with intubation during thrombectomy remains controversial. Aphasia may increase patient agitation or apparent uncooperativeness/confusion and thereby lead to higher use of GA. The purpose of this study was to identify risk factors for GA and determine if the side of vessel occlusion potentially impacts GA rates. MATERIALS AND METHODS: Patients who underwent mechanical thrombectomy of the middle cerebral artery (MCA) for acute ischemic stroke at our institution between April 2014 and July 2017 were retrospectively reviewed. Patient characteristics, procedural factors, and outcomes were assessed using multivariate regression analyses. Mediation analysis was utilized to investigate whether aphasia lies on the causal pathway between left-sided MCA stroke and GA. RESULTS: Overall, 112 patients were included: 62 with left-sided and 50 with right-sided MCA occlusion. Patients with left-sided MCA occlusion presented with aphasia significantly more often those with right-sided occlusion (90.3% vs. 32.0%; P<0.001). GA rates were significantly higher for patients with left-sided compared with right-sided MCA occlusion (45.2% vs. 20.0%; P=0.028). Aphasia mediated 91.3% of the effect of MCA stroke laterality on GA (P=0.02). GA was associated with increased door-to-groin-puncture time (106.4% increase; 95% confidence interval, 24.1%-243.4%; P=0.006) and adverse discharge outcome (odds ratio, 1.04; 95% confidence interval, 1.01-1.07; P=0.019). CONCLUSIONS: Patients who had a stroke with left-sided MCA occlusion are more likely to undergo GA for mechanical thrombectomy than those with right-sided MCA occlusion. Aphasia may mediate this effect and understanding this relationship may decrease GA rates through modification of management protocols, potentially leading to improved clinical outcomes. Our study suggests that GA should preferentially be considered for the subset of patients with acute ischemic stroke undergoing mechanical thrombectomy for left-sided MCA occlusion.

Hydrophilic polymer embolism identified in brain tumor specimens following Wada testing: A report of 2 cases.

Hydrophilic polymers are commonly used as coatings on intravascular medical devices. As intravascular procedures continue to increase in frequency, the risk of embolization of this material throughout the body has become evident. These emboli may be discovered incidentally but can result in serious complications including death. Here, we report the first two cases of hydrophilic polymer embolism (HPE) identified on brain tumor resection following Wada testing. One patient experienced multifocal vascular complications and diffuse cerebral edema, while the other had an uneventful postoperative course. Wada testing is frequently performed during preoperative planning prior to epilepsy surgery or the resection of tumors in eloquent brain regions. These cases demonstrate the need for increased recognition of this histologic finding to enable further correlation with clinical outcomes.