Nationwide trends in intensive care unit utilization in the elective endovascular treatment of unruptured intracranial aneurysms.

OBJECTIVE: Multiple studies suggest routine post-operative intensive care unit (ICU) stays after endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs) is unnecessary, though rates of ICU utilization nationwide are unknown. We aim to evaluate rates and characteristics of ICU utilization in patients undergoing elective endovascular repair of UIAs. METHODS: This is a retrospective cohort study utilizing a nationwide private-payer database in the United States to evaluate the ICU utilization in patients undergoing elective endovascular repair of UIAs between 2005 and 2019. Demographics and pre-operative comorbidities as well as post-procedural complications and discharge status were compared. An analysis of charges and costs was also performed. RESULTS: Among 6218 patients who underwent elective EVT of a UIA, 4890 (78.6%) were admitted to the ICU post-operatively. There were no differences in age, sex, or Charlson comorbidity scores in patients admitted to the ICU post-operatively compared to those admitted elsewhere. ICU utilization was more common in urban locations compared to rural. 12.7% of patients had ICU-specific needs sufficient to be billed by a critical care provider. Total provider costs were significantly higher in patients utilizing the ICU post-operatively, even among uncomplicated patients with routine discharges. CONCLUSION: Most patients undergoing elective endovascular UIA repair in the United States are admitted to the ICU postoperatively. Only 12.7% have ICU needs, and these patients are predictable from pre-operative characteristics or peri-operative complications. Reducing ICU use in this subgroup of patients may be an important target to improve healthcare value in this patient population.

Localization of spinal dural arteriovenous fistulas from the spatial relationships of perimedullary vessels on standard MRI.

OBJECTIVE: The goal in this study was to explore the spatial relationship of perimedullary vessels visualized on MRI to localize the side and the site of spinal dural arteriovenous fistula (SDAVF). METHODS: A retrospective analysis of 30 consecutive patients diagnosed with SDAVF on MRI was undertaken. Two experienced reviewers blinded to all reports and angiographic images analyzed T2-weighted as well as postcontrast T1-weighted sequences. A focal prominent zone of perimedullary vessels with lateralization to one side in the thecal space was evaluated to locate the side and the site of the fistula. Spinal digital subtraction angiography served as the gold standard technique. RESULTS: Good interrater agreement (κ = 0.77) was shown for the diagnosis of SDAVF with perimedullary vessels on T2-weighted MRI. Flow voids on T2-weighted MRI demonstrated a sensitivity of 1.0 (95% CI 1.0-1.0) and an accuracy of 0.87 (95% CI 0.79-0.95) to identify the presence of fistula. The flow voids on T2-weighted MRI also demonstrated 0.88 (95% CI 0.71-1.03) sensitivity and 0.81 (95% CI 0.70-0.92) accuracy to identify the side of SDAVF. Furthermore, flow voids on T2-weighted MRI showed 0.87 (95% CI 0.71-1.03) sensitivity and 0.87 (95% CI 0.79-0.95) accuracy to identify the site of SDAVF within 3 vertebral levels above or below the actual site. Area under the receiver operating characteristic curve demonstrated significant results (0.87 [95% CI 0.73-1.0]; p < 0.001) for flow voids on T2-weighted MRI to identify the site of shunts within 3 vertebral levels in the cranial or caudal direction. CONCLUSIONS: Spatial distribution of perimedullary vessels observed on standard MRI show promise to locate the side and the site of fistula in patients with SDAVF.

Safety and efficacy of endovascular versus microsurgical treatment of unruptured wide-necked middle cerebral artery aneurysms: a propensity score-matched analysis of the NeuroVascular Quality Initiative Quality Outcomes Database Cerebral Aneurysm Registry.

OBJECTIVE: Unruptured, wide-necked middle cerebral artery (WN-MCA) aneurysms have traditionally been considered ideal candidates for microsurgery (MS), although endovascular treatment (EVT) has dramatically increased in popularity with the advent of novel devices such as intrasaccular flow disruptors. The purpose of this study was to evaluate the safety and efficacy of MS versus EVT for unruptured WN-MCA aneurysms. METHODS: The NeuroVascular Quality Initiative Quality Outcomes Database (NVQI-QOD) Cerebral Aneurysm Registry, a multiinstitutional, prospectively collected procedural database, was queried for cases of unruptured WN-MCA aneurysms treated with MS or EVT between 2015 and 2022. A wide neck was defined as an aneurysm neck ≥ 4 mm or a dome/neck ratio ≤ 2. Demographics and aneurysm characteristics were queried. Propensity score matching (PSM) was utilized to match aneurysm size, number of aneurysms treated, patient age, and aneurysm status. Safety outcomes were evaluated including intraoperative and postoperative complication rates. Aneurysm occlusion status and clinical outcomes using the modified Rankin Scale (mRS) score at discharge and the last follow-up were also assessed. RESULTS: Of 671 unruptured MCA aneurysms, 319 were wide necked. Thirty cases were excluded, as the aneurysm had been previously treated. Two hundred eighty-nine operations (203 EVT, 86 MS) in 282 patients satisfied inclusion criteria. After PSM, there were 86 operations in each group for analysis. The mean aneurysm width was 5.0 (EVT) versus 4.9 mm (MS; p = 0.285). Safety data showed similar intraoperative (7.0% EVT vs 3.5% MS, p = 0.496) and postoperative (4.7% vs 7%, p = 0.746) complication rates. The MS patients were more likely to have complete aneurysm occlusion at discharge (90.4% vs 58.8%, p < 0.001). In a limited subset of patients (52.9%) for whom outcome data were available, the EVT patients were more likely to have an mRS score 0 at discharge (50/59 [84.7%] vs 29/54 [53.7%], p < 0.0003] and at the last follow-up (36/55 [65.5%] vs 13/36 [36.1%], p = 0.006). CONCLUSIONS: This study describes a large, modern cohort of propensity score-matched patients who underwent treatment of unruptured WN-MCA aneurysms. Safety data on intraoperative and postoperative complication rates were similar in both treatment groups. MS was more likely to result in complete aneurysm occlusion at discharge. In a subset of patients with available outcome data, EVT was associated with better functional outcomes at discharge and the last follow-up. Given the lack of complete follow-up data and rates of retreatment, these results should be interpreted cautiously.

Conscious sedation by sedation-trained interventionalists versus anesthesia providers in patients with acute ischemic stroke undergoing endovascular thrombectomy: A propensity score-matched analysis.

BACKGROUND: The appropriate choice of perioperative sedation during endovascular thrombectomy for ischemic stroke is unknown. Few studies have evaluated the role of nursing-administered conscious sedation supervised by a trained interventionalist. OBJECTIVE: To compare the safety and efficacy of endovascular thrombectomy for ischemic stroke performed with nursing-administered conscious sedation supervised by a trained interventionalist with monitored anesthesia care supervised by an anesthesiologist. METHODS: A retrospective review of a prospectively collected stroke registry was performed. The primary outcome was functional independence at 90 days, defined as a modified Rankin score of 0-2. Propensity score matching was performed to control for known confounders including patient comorbidities, access type, and direct-to-suite transfers. RESULTS: A total of 355 patients underwent endovascular thrombectomy for large vessel occlusion between 2018 and 2022. Thirty five patients were excluded as they arrived at the endovascular suite intubated. Three hundred and twenty patients were included in our study, 155 who underwent endovascular thrombectomy with nursing-administered conscious sedation and 165 who underwent endovascular thrombectomy with monitored anesthesia care. After propensity score matching, there were 111 patients in each group. There was no difference in modified Rankin score 0-2 at 90 days (26.1% vs 35.1%, p = 0.190). Patients undergoing monitored anesthesia care received significantly more vasoactive medications (23.4% vs 49.5%, p < 0.001) and had a lower intraoperative minimum systolic blood pressure (134 vs 123 mmHg, p < 0.046). There was no difference in procedural efficacy, safety, intubation rates, and postoperative complications. CONCLUSION: Perioperative sedation with nursing-administered conscious sedation may be safe and effective in patients undergoing endovascular thrombectomy for ischemic stroke.

Lessons for the pathogenesis of vasospasm from a patient with sickle cell disease, moyamoya disease, subarachnoid hemorrhage, and 1 month of persistent vasospasm: illustrative case.

BACKGROUND: The mechanism of vasospasm post-subarachnoid hemorrhage (post-SAH) is a poorly understood yet devastating complication that can result in delayed ischemic neurological damage. High concentrations of free hemoglobin present in hemolytic conditions reduce nitric oxide (NO) availability which may disrupt vascular dynamics and contribute to the extent of vasospasm. OBSERVATIONS: The authors describe the clinical course of a sickle cell disease (SCD) patient with spontaneous SAH who suffered an abnormally long duration of vasospasm. The authors then present a focused review of the pathology of intravascular hemolysis and discuss the potential key role of intravascular hemolysis in the pathogenesis of cerebral vasospasm as illustrated in this case lesson. LESSONS: Abnormally prolonged and severe vasospasm in SCD with SAH may provide clues regarding the mechanisms of vasospasm. Intravascular hemolysis limits NO availability and may contribute to the development of vasospasm following SAH.

Acute Calcific Cerebral Embolism Large Vessel Occlusion: A Unique Stroke Mechanism With Hard Challenges.

We present the case of an ischemic stroke associated with partially occlusive acute calcified cerebral emboli large vessel occlusion (CCE LVO). No revascularization strategy guidelines have been established for this unique acute ischemic stroke population, although many studies have reported impaired and inconsistent responses to both thrombolysis and thrombectomy. The patient in this case report, unfortunately, experienced a failed attempt at complete thrombolysis, resulting in a poor clinical outcome. Endovascular thrombectomy was not performed because of incomplete obstruction and risk of injury. Follow-up imaging revealed an acute ischemic stroke at the large middle cerebral artery and a new intraparenchymal hemorrhage with complete absence of the previously identified calcified embolus. This case and current literature demonstrate that more data are needed to determine the best revascularization approach for patients with CCE LVO stroke. With tissue plasminogen activator marginally effective in these patients, thrombectomy should be considered in highly unstable, clinically symptomatic patients even only with partial vessel occlusion.

Role of Indocyanine Green with FLOW 800 in Removal of Hidden Arteriovenous Malformations.

OBJECTIVE: Indocyanine green videoangiography (ICG-VA) with FLOW 800 (Carl Zeiss AG) has been used as a visualization tool to guide arteriovenous malformation (AVM) surgery since 2011. We performed a systematic review and evaluated the quality of evidence available on this topic. In addition, we present a series of our own cases demonstrating the unique use of ICG-VA in the localization and removal of deeper seated AVMs. METHODS: Using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines for systematic reviews, we identified studies related to ICG-VA with FLOW 800 in AVM surgeries using search terms. The studies were screened and reviewed, and the quality of evidence was analyzed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) criteria. We performed a retrospective review of our own cases of AVM removal with ICG-VA and FLOW 800. RESULTS: Our search revealed 27 relevant studies, 17 of which met our inclusion criteria. The quality of the body of evidence was determined to be "very low" using the GRADE criteria. We used ICG-VA with FLOW 800 analysis for 14 cases of microsurgical AVM removal. This technique provided unique insights into the localization of deep seated AVMs in 8 cases (57%). No residual AVM was found when assessed by the 6-month follow-up angiogram. CONCLUSIONS: We present cases highlighting the usefulness of this technique for the localization of certain AVMs. We believe the use of ICG-VA can guide the removal of deeper seated AVMs, because it can reveal surface feeders and draining veins that can be followed to a hidden nidus. Larger, registry-based studies are needed to confirm these findings and improve the overall quality of evidence.

Unruptured Arteriovenous Malformations in the Multidetector Computed Tomography Era: Frequency of Detection and Predictable Failures.

OBJECTIVES: While hemorrhage arising from ruptured arteriovenous malformations (AVMs) is usually evident on multidetector non-contrast computed tomography (NCCT), unruptured AVMs can be below the limits of detection. We performed a retrospective review of NCCT of patients with a proven diagnosis of unruptured AVM to determine if advances in CT technology have made them more apparent and what features predict their detection. MATERIAL AND METHODS: Twenty-five NCCTs met inclusion criteria of having angiography or MR proven AVM without hemorrhage, prior surgery, or other CNS disease. Demographic variables, clinical symptoms at presentation, abnormal CT imaging findings, attenuation of the superior sagittal sinus (SSS), and Spetzler-Martin grade of each AVM were recorded. We examined the relationship between AVM detection and SSS attenuation through Kruskal-Wallis test. Exploratory serial logistic principal components analysis was performed including demographics, symptoms, and CT features in the multivariate model. RESULTS: About 80% of the NCCTs showed an abnormality while 20% were normal. All those with an identifiable abnormality showed hyperdensity (80%). Logistic regression models indicate that clustered associations between several CT features, primarily calcifications, hyperdensity, and vascular prominence significantly predicted Spetzler-Martin grade (likelihood ratio 7.7, P = 0.006). SSS attenuation was significantly lower in subjects with occult AVMs when compared to those with CT abnormalities (median 47 vs. 55 HU, P < 0.04). CONCLUSION: Abnormal hyperdensity was evident in all detectable cases (80%) and multiple CT features were predictive of a higher Spetzler-Martin AVM grade. Moreover, SSS attenuation less than 50 HU was significantly correlated with a false-negative NCCT.

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

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

Risk Factors Associated with ICU-Specific Care in Patients Undergoing Endovascular Treatment of Unruptured Intracranial Aneurysms.

BACKGROUND: Multiple studies suggest routine postoperative intensive care unit (ICUs) stays in presumed high-risk neurosurgical procedures may be unnecessary. Our objective was to evaluate the risk factors associated with ICU-specific needs in patients undergoing elective endovascular treatment of unruptured intracranial aneurysms. METHODS: A retrospective review of consecutive patients undergoing elective endovascular treatment of unruptured aneurysms was performed between January 2010 and January 2020 in a single academic medical center. Patient demographic information, aneurysm and treatment characteristics, intraoperative and postoperative complications, as well as ICU-specific needs, were abstracted. The primary outcome was ICU-specific needs. RESULTS: A total of 382 patient encounters in 344 unique patients were abstracted. 13.6% (52 of 382) of patient encounters had an ICU-specific need. Multivariate analysis revealed that age [adjusted odds ratio (OR) 1.04, 95% confidence interval (CI) 1.01-1.07, p = 0.03], procedure duration greater 200 min (adjusted OR 2.75, 95% CI 1.34-5.88, p = 0.007), and any intraoperative complication (adjusted OR 20.41, CI 7.97-56.57, p < 0.001) were independent predictors of postoperative ICU-specific needs. The majority of ICU-specific needs (94%, 49 of 52) occurred within 6 h of surgery. CONCLUSIONS: Our results show that age, procedure duration greater than or equal to 200 min, and intraoperative complication were independent predictors of postoperative ICU-specific needs in patients presenting for elective endovascular treatment of unruptured intracranial aneurysms. The majority of ICU-specific needs and associated complications occurred in the immediate postoperative period. This data can be used to help decide the appropriate postoperative level of care in this patient population.

Balloon-Assisted Roadmap Technique to Enable Flow Diversion of a High-Flow Direct Carotid-Cavernous Fistula.

BACKGROUND: The use of flow diverters as a first-line treatment for direct carotid cavernous fistula (CCF) is a relatively new approach in the neurointerventional field which allows obliteration of the fistula with less mass effect from coils in the cavernous sinus. Safe and successful deployment of a flow diverter requires adequate imaging of the parent vessel, which may be challenging in the setting of high-flow CCF without antegrade flow. OBJECTIVE: To facilitate adequate parent vessel imaging in the setting of high-flow CCF to enable the safe development of a flow diverter device. METHODS: Here we present the case of a patient with delayed presentation of post-traumatic direct CCF after a motor vehicle accident, with no antegrade flow past the fistulous connection. We used temporary balloon occlusion of the fistulous connection to enable road-map imaging of the parent vessel and flow-diverter placement. "Drag and drop" device opening in the middle cerebral artery facilitated better deployment of the flow-diverter against retrograde cavernous flow through the fistula. RESULTS: Temporary balloon occlusion of the fistulous connection was used to acquire a roadmap to facilitate safe deployment of a flow diverter and subsequent treatment of the CCF with transvenous coil embolization, with complete resolution of symptoms. CONCLUSION: Balloon-assisted roadmap use is a novel means of visualizing the parent vessel in direct CCF to facilitate safe flow diverter deployment.

Management of neurophysiological monitoring changes during carotid endarterectomy exposure.

BACKGROUND: Carotid endarterectomy (CEA) is a safe and effective operation in the management of carotid stenosis. Intraoperative neurophysiologic monitoring (IONM) changes during carotid clamping has been well studied, but there is scant evidence detailing IONM changes during carotid exposure. OBJECTIVE: We analyzed our experience with IONM changes during CEA exposure to determine whether multimodal IONM changes during exposure predict outcomes and how best to manage this challenging clinical scenario. METHODS: We reviewed all CEAs performed at our medical center between January 2015 and June 2020 and identified patients with multimodal IONM changes during exposure of the carotid artery. Our primary outcomes were perioperative stroke and functional outcomes. Functional outcomes were measured by modified Rankin scale (mRS), with good functional outcome defined at mRS scores 0-3. We also reviewed our intraoperative IONM change management strategies. RESULTS: Five patients (4 males, 1 female) with an average age of 67 ± 12 years had intraoperative IONM changes during carotid exposure. Among these, three patients were discharged with good functional outcome, and four patients had a good functional outcome at last follow-up. Two patients had perioperative stroke, half of which resulted in significant disability. One patient was transferred to the neuroendovascular suite intraoperatively for evaluation for thromboembolism followed by angioplasty and stenting with distal protection. CONCLUSION: Intraoperative IONM changes during carotid exposure predict outcomes in CEA. We propose that transition to the neuroendovascular suite following significant IONM changes during carotid exposure may be a useful strategy for management of this challenging clinical scenario. This approach provides the opportunity to evaluate and treat thromboembolism and still complete carotid revascularization when appropriate. This algorithm may be particularly useful in the era of dual trained vascular neurosurgeons.

Management of Internal Carotid Artery and Intracranial Anterior Circulation Tandem Occlusion with Stenting versus No Stenting: A Multicenter Study.

BACKGROUND: Tandem occlusion (TO) describes not only occlusion of the middle cerebral artery but a contemporaneous occlusion of the cervical internal carotid artery. There is a paucity of data over whether mechanical thrombectomy (MT) alone, MT with angioplasty, or MT with carotid artery stent placement is superior. We aim to address a gap in the literature comparing carotid stenting with mechanical thrombectomy (CSMT) and carotid angioplasty with mechanical thrombectomy (CAMT) in patients presenting with acute anterior circulation TOs. METHODS: This is a multicenter, retrospective study from 2012 to 2020 comparing CSMT and CAMT presenting with acute anterior circulation TOs. Primary outcomes of interest were functional status, perioperative stroke, mortality, and symptomatic intracranial hemorrhage (sICH). A total of 92 patients (66 vs. 26 in CSMT and CAMT, respectively) met inclusion criteria for analysis. RESULTS: There was no statistically significant difference in functional outcomes at 90-day follow-up (adjusted odds ratio [aOR] 0.82; 95% confidence interval [CI] 0.20-3.5; P = 0.46). In addition, there was no statistically significant difference in 90-day mortality (aOR 0.361; 95% CI 0.016-2.92; P = 0.532) and perioperative stroke rate (aOR 1.76; 95% CI 0.160-15.6; P = 0.613). However, sICH risk was significantly greater in the stent-treated cohort (aOR 3.94; 95% CI 0.529-37.4; P = 0.003). CONCLUSIONS: Functional outcomes, mortality, and perioperative stroke rates do not significantly differ in CSMT and CAMT procedures in the acute setting. However, CSMT-treated patients do appear to have an increased risk of sICH, potentially due to the use of additional antiplatelet agents following stent placement.

A Systematic Review and Meta-Analysis of Antiepileptic Prophylaxis in Spontaneous Intracerebral Hemorrhage.

BACKGROUND: Frequency of clinical seizures may be as high as 16% in patients with spontaneous intracerebral hemorrhage (ICH). Current guidelines recommend against antiepileptic drug (AED) prophylaxis, but this recommendation is based on older trials, and the effect of newer AEDs is uncertain. The aim of this review was to study effects of AEDs on seizure occurrence and outcome in patients with spontaneous ICH. METHODS: We searched key databases using combinations of the following terms: "levetiracetam," "prophylaxis," "ICH," "intracerebral hemorrhage," "intraparenchymal hemorrhage." Selected studies were reviewed for level of evidence and overall quality of data using Grading of Recommendations, Assessment, Development and Evaluations criteria. A meta-analysis was performed to evaluate seizure prevention, functional outcome, and mortality in patients with seizure prophylaxis compared with no prophylaxis following spontaneous ICH. RESULTS: Seven articles met inclusion criteria and were graded level III studies. Administration of AEDs was not associated with reduced seizure risk (odds ratio 1.14, 95% confidence interval 0.47-2.77, P = 0.77). There was an association between AED prophylaxis and poor functional outcome (odds ratio 1.65, 95% confidence interval 1.17-2.31, P = 0.004) but not mortality (odds ratio 1.04, 95% confidence interval 0.62-1.72, P = 0.89). The overall quality of evidence using Grading of Recommendations, Assessment, Development and Evaluations criteria was low. CONCLUSIONS: This systematic review and meta-analysis including recent studies focusing on newer AEDs supports the 2015 guidelines regarding AED use in spontaneous ICH. There are some important caveats, including a possible confounding association between AED use and higher ICH score and the overall poor quality of the available data. A randomized clinical trial may be helpful.

Effect of Blood Pressure Management Strategies on Outcomes in Patients with Acute Ischemic Stroke After Successful Mechanical Thrombectomy.

BACKGROUND: Variability, with no general consensus, exists in how patients' blood pressure should be managed after successful mechanical thrombectomy (MT) for large vessel ischemic stroke. We examined whether exceeding the systolic blood pressure (SBP) targets in patients during the first 24 hours after successful MT led to worse outcomes. METHODS: We retrospectively studied a consecutive sample of adult patients who had undergone MT. We collected SBP data for the first 24 hours after MT and categorized the patients into 3 groups according to cases of the SBP exceeding 140, 160, or 180 mm Hg. The primary and secondary outcomes were the modified Rankin scale score at discharge and 90 days of follow-up, the incidence of symptomatic intracranial hemorrhage, malignant cerebral edema, and hemicraniectomy, mortality within 90 days, and discharge disposition. RESULTS: A total of 117 patients were included (mean age, 65 ± 13.12 years; 53% female). The occurrence of ≥1 instance of SBP ≥180 mm Hg was significantly associated with poor functional outcomes at discharge (adjusted odds ratio [OR], 5.83; 95% confidence interval [CI], 1.41-32.9; P = 0.025) but not at 90 days of follow-up. The occurrence of SBP ≥160 mm Hg resulted in an independently increased odds of malignant cerebral edema (adjusted OR, 17.07; 95% CI, 2.56-174.4; P = 0.01), with a trend toward increased odds of symptomatic intracranial hemorrhage (adjusted OR, 4.42; 95% CI, 1.03-21.2; P = 0.0503). CONCLUSIONS: These results suggest that individual instances of SBP elevation alone after successful MT, rather than a necessarily prolonged increased blood pressure as reflected by the mean or median SBP values, can significantly affect the clinical outcomes after successful MT.

Side-to-side reverse superficial temporal artery to M4 middle cerebral artery bypass for common carotid artery occlusion with bonnet collaterals: illustrative case.

BACKGROUND: The bonnet bypass was initially described for common carotid artery occlusion. Considered a second-generation bypass, it augments intracranial perfusion with contralateral external carotid artery flow through an interposition graft running over the scalp vertex. However, the traditional first-generation low-flow superficial temporal artery (STA)-M4 middle cerebral artery (MCA) bypass may be enhanced by performing a side-to-side (S-S) bypass with an intraluminal suture technique (fourth-generation bypass) to increase perfusion through antegrade and retrograde flow. OBSERVATIONS: The authors present a reimagined S-S STA-M4 bypass in the case of a patient with symptomatic common carotid occlusion, in which the ipsilateral STA filled in a reverse fashion from the contralateral external carotid branches over the scalp vertex (bonnet collaterals). By performing an S-S anastomosis, the authors were able to improve cerebral perfusion and avoid the multiple anastomosis sites of the bonnet bypass. LESSONS: The patient had a good recovery with resolution of his preoperative symptoms. Follow-up angiography showed a patent bypass supplying the MCA territory through retrograde flow in the frontal and parietal limbs of the STA, converging at the anastomosis site. In this report, the authors present a new fourth-generation bypass dubbed the "S-S reverse STA-M4 MCA bypass."

Staged Surgical Resection of Brain Arteriovenous Malformations.

BACKGROUND: Staged treatment of brain arteriovenous malformations (AVMs) is sometimes necessary to minimize risks associated with sudden changes in cerebral hemodynamics. With the increasing availability and optimization of endovascular techniques, multiple surgical resections are rarely necessary, although, due to specific anatomic circumstances, some AVMs still require staged surgery. Here, we describe the largest reported series of staged surgical resections of brain AVMs. METHODS: This is a retrospective review of surgically resected AVMs at a single institution from 1998-2018. Patients who underwent ≥2 resections within 1 year were reviewed. Only those in whom initial resection was terminated with intention for further resection were included in analysis. RESULTS: Twenty patients underwent deliberately staged resection from 1998-2018. Average age at treatment was 36.2 years (SD 16.5 years). Eleven patients (55%) were female, and 12 (60%) had left-sided AVMs. Median Spetzler-Martin grade was 4 (interquartile range [IQR]: 3-4). Average AVM nidus diameter was 5.0 cm (SD 1.7 cm). Seven patients (35%) presented with AVM rupture, and 12 (60%) presented with focal neurologic deficits without hemorrhage. Seventeen patients (85%) underwent preoperative embolization, median number of embolizations was 3 (IQR: 2-4). Three patients (15%) underwent preoperative radiosurgery. Median number of days between surgeries was 28 (IQR: 8-41 days). Perioperative course was complicated by hemorrhage in 3 patients (15%); 1 required decompressive hemicraniectomy prior to the second stage of surgery. Good functional outcome (defined as modified Rankin Scale score ≤2) was achieved in 14 patients (70%). CONCLUSIONS: Staged surgical resection of large and complex AVMs can be performed with good outcomes in carefully selected patients.