Use of minimally invasive ultrasound transducer during tubular microdiscectomy.

Minimally invasive ultrasound during tubular microdiscectomy is novel. The authors report the technique during surgery for L5-S1 herniated disc. Ultrasound provided real-time visualization of the pathology and neural elements. After discectomy and tactile assessment, ultrasound showed decompression of the thecal sac and traversing nerve root. The patient tolerated the procedure well, with resolution of preoperative pain and strength improvement. Postoperative MRI revealed a residual asymptomatic disc fragment that was retrospectively identified on ultrasonography. Minimally invasive ultrasound could become a useful supplement to direct visual and tactile assessment during tubular microdiscectomy, but further experience with surgical anatomy on ultrasound is required. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23206.

Fatty filum terminale and low-lying conus medullaris in Gollop-Wolfgang complex: a case report and review of literature.

BACKGROUND/IMPORTANCE: Gollop-Wolfgang complex is a rare skeletal dysplasia with only 200 cases reported in the literature. This disorder is usually associated with several extraosseous anomalies. This report describes the first case of a fatty filum terminale and a low-lying conus medullaris in a patient with this complex. A review of the current literature of the Gollop-Wolfgang complex accompanies this case, highlighting the documented extraosseous anomalies seen in this complex. CLINICAL PRESENTATION: We report a case of an 18-month-old patient with Gollop-Wolfgang complex who underwent cord untethering with release of the filum terminale after extensive workup showed the presence of a dyssynergic bladder and radiological evaluation revealed a fatty filum terminale and low-lying conus medullaris. CONCLUSION: Gollop-Wolfgang complex is a skeletal dysplasia usually associated with several extra skeletal anomalies. Our report describes the first case of a fatty filum terminale and low-lying conus medullaris in this complex, as well as provides an overview of the documented anomalies seen in this disorder. A multidisciplinary approach is recommended when treating these infants in order to ensure that occult manifestations of the complex are not missed.

Magnetic Resonance Angiography After Flow Diversion: The Use of Complementary Magnetic Resonance Angiography Techniques to Monitor Aneurysm Occlusion and Device and Arterial Branch Patency After Flow Diverter Placement.

BACKGROUND: Few studies have evaluated flow diversion with magnetic resonance angiography (MRA). Studies have shown better success of MRA in assessing the aneurysm response, but limited success in assessing stent patency. The patency of arterial branches on MRA remains to be explored. METHODS: Retrospective evaluation of 31 consecutive cases of carotid aneurysms treated with flow diversion was performed with noncontrast time-of-flight (TOF), contrast-enhanced TOF, and cine MRA (time-resolved angiography with interleaved stochastic trajectories) independently by 2 investigators for aneurysm occlusion, stent patency, and arterial branch patency. Digital subtraction angiography served as the gold standard technique. RESULTS: Patients were 6 men and 25 women with a mean ± SD age of 57.8 ± 12.27 years (range, 32-79 years). Stent patency, aneurysm occlusion, and branch patency mostly revealed substantial to perfect interobserver agreement (κ >0.60). Sensitivity, specificity, positive predictive value, and negative predictive value for stent patency on raw data images of TOF were 0.50, 0.86, 0.20, and 0.96 and on contrast-enhanced TOF were 1.0, 0.93, 0.50, and 1.0. Ranges for aneurysm response on the 3 MRA scans were 0.78-0.89 for sensitivity, 0.54-0.92 for specificity, 0.73-0.93 for positive predictive value, and 0.78-0.86 for negative predictive value. Ranges for arterial branch patency among the 3 MRA scans were 0.87-0.96 for sensitivity, 0.50-1.0 for specificity, 0.90-1.0 for positive predictive value, and 0.33-0.80 for negative predictive value. CONCLUSIONS: Aneurysm occlusion, stent patency, and arterial branch patency in flow diversion can be successfully evaluated with the combination of 3 MRA techniques.

Educational impact of early COVID-19 operating room restrictions on neurosurgery resident training in the United States: A multicenter study.

BACKGROUND: The coronavirus (COVID-19) pandemic has caused unprecedented suspensions of neurosurgical elective surgeries, a large proportion of which involve spine procedures. The goal of this study is to report granular data on the impact of early COVID-19 pandemic operating room restrictions upon neurosurgical case volume in academic institutions, with attention to its secondary impact upon neurosurgery resident training. This is the first multicenter quantitative study examining these early effects upon neurosurgery residents caseloads. METHODS: A retrospective review of neurosurgical caseloads among seven residency programs between March 2019 and April 2020 was conducted. Cases were grouped by ACGME Neurosurgery Case Categories, subspecialty, and urgency (elective vs. emergent). Residents caseloads were stratified into junior (PGY1-3) and senior (PGY4-7) levels. Descriptive statistics are reported for individual programs and pooled across institutions. RESULTS: When pooling across programs, the 2019 monthly mean (SD) case volume was 214 (123) cases compared to 217 (129) in January 2020, 210 (115) in February 2020, 157 (81), in March 2020 and 82 (39) cases April 2020. There was a 60% reduction in caseload between April 2019 (207 [101]) and April 2020 (82 [39]). Adult spine cases were impacted the most in the pooled analysis, with a 66% decrease in the mean number of cases between March 2020 and April 2020. Both junior and senior residents experienced a similar steady decrease in caseloads, with the largest decreases occurring between March and April 2020 (48% downtrend). CONCLUSIONS: Results from our multicenter study reveal considerable decreases in caseloads in the neurosurgical specialty with elective adult spine cases experiencing the most severe decline. Both junior and senior neurosurgical residents experienced dramatic decreases in case volumes during this period. With the steep decline in elective spine cases, it is possible that fellowship directors may see a disproportionate increase in spine fellowships in the coming years. In the face of the emerging Delta and Omicron variants, programs should pay attention toward identifying institution-specific deficiencies and developing plans to mitigate the negative educational effects secondary to such caseloads reduction.

Embolization of Brain Arteriovenous Malformations With Versus Without Onyx Before Stereotactic Radiosurgery.

BACKGROUND: Embolization of brain arteriovenous malformations (AVMs) using ethylene-vinyl alcohol copolymer (Onyx) embolization may influence the treatment effects of stereotactic radiosurgery (SRS) differently than other embolysates. OBJECTIVE: To compare the outcomes of pre-SRS AVM embolization with vs without Onyx through a multicenter, retrospective matched cohort study. METHODS: We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Embolized AVMs treated with SRS were selected and categorized based on embolysate usage into Onyx embolization (OE + SRS) or non-Onyx embolization (NOE + SRS) cohorts. The 2 cohorts were matched in a 1:1 ratio using de novo AVM features for comparative analysis of outcomes. RESULTS: The matched cohorts each comprised 45 patients. Crude AVM obliteration rates were similar between the matched OE + SRS vs NOE + SRS cohorts (47% vs 51%; odds ratio [OR] = 0.837, P = .673). Cumulative probabilities of obliteration were also similar between the OE + SRS vs NOE + SRS cohorts (subhazard ratio = 0.992, P = .980). Rates of post-SRS hemorrhage, all-cause mortality, radiation-induced changes, cyst formation, and embolization-associated complications were similar between the matched cohorts. Sensitivity analysis for AVMs in the OE + SRS cohort embolized with Onyx alone revealed a higher rate of asymptomatic embolization-associated complications in this subgroup compared to the NOE + SRS cohort (36% vs 15%; OR = 3.297, P = .034), but the symptomatic complication rates were similar. CONCLUSION: Nidal embolization using Onyx does not appear to differentially impact the outcomes of AVM SRS compared with non-Onyx embolysates. The embolic agent selected for pre-SRS AVM embolization should reflect both the experience of the neurointerventionalist and target of endovascular intervention.

Stereotactic Radiosurgery With Versus Without Embolization for Brain Arteriovenous Malformations.

BACKGROUND: Prior comparisons of brain arteriovenous malformations (AVMs) treated using stereotactic radiosurgery (SRS) with or without embolization were inherently flawed, due to differences in the pretreatment nidus volumes. OBJECTIVE: To compare the outcomes of embolization and SRS, vs SRS alone for AVMs using pre-embolization malformation features. METHODS: We retrospectively reviewed International Radiosurgery Research Foundation AVM databases from 1987 to 2018. Patients were categorized into the embolization and SRS (E + SRS) or SRS alone (SRS-only) cohorts. The 2 cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was defined as AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiologic and symptomatic radiation-induced changes (RIC), and cyst formation. RESULTS: The matched cohorts each comprised 101 patients. Crude AVM obliteration rates were similar between the matched E + SRS vs SRS-only cohorts (48.5% vs 54.5%; odds ratio = 0.788, P = .399). Cumulative probabilities of obliteration at 3, 4, 5, and 6 yr were also similar between the E + SRS (33.0%, 46.4%, 56.2%, and 60.8%, respectively) and SRS-only (32.9%, 46.2%, 56.0%, and 60.6%, respectively) cohorts (subhazard ratio (SHR) = 1.005, P = .981). Cumulative probabilities of radiologic RIC at 3, 4, 5, and 6 yr were lower in the E + SRS (25.0%, 25.7%, 26.7%, and 26.7%, respectively) vs SRS-only (45.3%, 46.2%, 47.8%, and 47.8%, respectively) cohort (SHR = 0.478, P = .004). Symptomatic and asymptomatic embolization-related complication rates were 8.3% and 18.6%, respectively. Rates of post-SRS hemorrhage, all-cause mortality, symptomatic RIC, and cyst formation were similar between the matched cohorts. CONCLUSION: This study refutes the prevalent notion that AVM embolization negatively affects the likelihood of obliteration after SRS.

Stereotactic radiosurgery with versus without prior Onyx embolization for brain arteriovenous malformations.

OBJECTIVE: Investigations of the combined effects of neoadjuvant Onyx embolization and stereotactic radiosurgery (SRS) on brain arteriovenous malformations (AVMs) have not accounted for initial angioarchitectural features prior to neuroendovascular intervention. The aim of this retrospective, multicenter matched cohort study is to compare the outcomes of SRS with versus without upfront Onyx embolization for AVMs using de novo characteristics of the preembolized nidus. METHODS: The International Radiosurgery Research Foundation AVM databases from 1987 to 2018 were retrospectively reviewed. Patients were categorized based on AVM treatment approach into Onyx embolization (OE) and SRS (OE+SRS) or SRS alone (SRS-only) cohorts and then propensity score matched in a 1:1 ratio. The primary outcome was AVM obliteration. Secondary outcomes were post-SRS hemorrhage, all-cause mortality, radiological and symptomatic radiation-induced changes (RICs), and cyst formation. Comparisons were analyzed using crude rates and cumulative probabilities adjusted for competing risk of death. RESULTS: The matched OE+SRS and SRS-only cohorts each comprised 53 patients. Crude rates (37.7% vs 47.2% for the OE+SRS vs SRS-only cohorts, respectively; OR 0.679, p = 0.327) and cumulative probabilities at 3, 4, 5, and 6 years (33.7%, 44.1%, 57.5%, and 65.7% for the OE+SRS cohort vs 34.8%, 45.5%, 59.0%, and 67.1% for the SRS-only cohort, respectively; subhazard ratio 0.961, p = 0.896) of AVM obliteration were similar between the matched cohorts. The secondary outcomes of the matched cohorts were also similar. Asymptomatic and symptomatic embolization-related complication rates in the matched OE+SRS cohort were 18.9% and 9.4%, respectively. CONCLUSIONS: Pre-SRS AVM embolization with Onyx does not appear to negatively influence outcomes after SRS. These analyses, based on de novo nidal characteristics, thereby refute previous studies that found detrimental effects of Onyx embolization on SRS-induced AVM obliteration. However, given the risks incurred by nidal embolization using Onyx, this neoadjuvant intervention should be used judiciously in multimodal treatment strategies involving SRS for appropriately selected large-volume or angioarchitecturally high-risk AVMs.

The Hydrogel Endovascular Aneurysm Treatment Trial (HEAT): A Randomized Controlled Trial of the Second-Generation Hydrogel Coil.

BACKGROUND: Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm. OBJECTIVE: To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT). METHODS: HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during follow-up, aneurysm occlusion stability, and clinical outcome at final follow-up. RESULTS: A total of 600 patients were randomized (HES, n = 297 and BPC, n = 303), including 28% with ruptured aneurysms. Recurrence occurred in 11 (4.4%) subjects in the HES arm and 44 (15.4%) subjects in the BPC arm (P = .002). While the initial occlusion rate was higher with BPC, the packing density and both major and minor recurrence rates were in favor of HES. Secondary endpoints including adverse events, retreatment, hemorrhage, mortality, and clinical outcome did not differ between arms. CONCLUSION: Coiling of small-to-medium aneurysms with second-generation HES resulted in less recurrence when compared to BPC, without increased harm. These data further support the use of the second-generation HES for the embolization of intracranial aneurysms.

Leptomeningeal Carcinomatosis from Squamous Cell Carcinoma of the Ethmoid Sinus: A Case Report.

Leptomeningeal carcinomatosis (LMC) is an end-stage disease with poor prognosis. This disease has not yet been reported with sinonasal carcinomatosis. We present a case of a patient who presented with posterior ethmoid/anterior cranial mass which turned out to be poorly differentiated squamous cell carcinoma (SCC). Later the patient presented with enhancement of the spinal roots and a lumbar puncture diagnosed the leptomeningeal spread of her primary disease. After intrathecal chemotherapy and palliative radiation, the patient failed to resist her disease seven months after the diagnosis. We present the first case report of leptomeningeal spread of sinonasal cancer. Although it seems rare, LMC should be on the differential of patients presenting with neurological deficits.

Y-shaped LVIS Stent-assisted Coiling of Anterior Communicating Artery Aneurysms: A Case Series.

Intracranial neurovascular stents are primarily used in stent-assisted coil embolization in the treatment of intracranial aneurysms. Recent studies suggest that a variety of these stents can be used for their flow diverting effects to obliterate intracranial aneurysms. In our series, we present two patients with ruptured intracranial aneurysms who presented with recurrent aneurysm that was successfully treated with double Low Profile Visualized Intraluminal Support Junior (LVIS Jr.) stent placement.

Utility of Tubular Retractors Augmented with Intraoperative Ultrasound in the Resection of Deep-seated Brain Lesions: Technical Note.

Traditional brain retraction has been associated with significant damage to the healthy brain tissue particularly when attempting to expose a deep-seated lesion of the brain. Tubular retractors tend to provide a surgical corridor to treat these lesions while minimizing the extent of retraction on the brain. Intraoperative ultrasound can be used as a handy adjunct in maximizing the safe resection primarily by identifying the entry point, visualizing the lesion, and providing real-time feedback on the extent of resection. The authors provide a technical note with case illustrations on the use of tubular retractors augmented with intraoperative ultrasound to ensure a maximal safe resection of deep-seated brain lesions.

Utility of Early Postoperative Magnetic Resonance Imaging After Glioblastoma Resection: Implications on Patient Survival.

BACKGROUND: The standard of care for glioblastoma is surgical resection followed by combination temozolomide and radiation. Magnetic resonance imaging (MRI) is used preoperatively for tumor resection planning. In some instances, MRI is also obtained postoperatively to assess for any complications and to determine extent of resection. There is some question whether early routine postoperative imaging of patients after tumor resection is beneficial to long-term outcomes, especially with the increased scrutiny of increasing health care costs. METHODS: In this study we retrospectively analyze patients with glioblastoma treated at our institution, comparing the difference in overall survival and treatment regimens between patients who had early postoperative MRI versus patients who did not. RESULTS: We determine that in our cohort of 125 patients, those with early postoperative MRI had no statistically significant overall survival difference compared with patients with no early postoperative MRI (P = 0.996). The median survival for the group with postoperative MRI was 378 days (95% confidence interval [CI], 242-443 days), and the median survival for the group without postoperative MRI was 308 days (95% CI, 203-445 days). Early postoperative MRI also did not significantly alter therapeutic regimens. CONCLUSIONS: Although early postoperative MRI may not significantly affect patient overall survival from a statistical standpoint or therapeutic regimens, this type of imaging may be important to hone resident and attending skill. We encourage other institutions to perform similar analyses to determine the overall survival benefit of early postoperative imaging after glioma resection for patients with glioblastoma.

Crossed Aphasia as a Manifestation of Glioblastoma.

Language and speech function is commonly accepted to be a heavily lateralized function. Greater than 95% of right-handed individuals have left hemispheric dominance for language, and reports in the literature of crossed aphasia (language deficits in a right-handed individual from right-sided pathology) are scant. We report the case of a 52-year-old woman presenting with crossed aphasia from a right temporal glioblastoma. We then expand on a discussion of crossed aphasia in the setting of brain tumors.

Outcomes After Off-Label Use of the Pipeline Embolization Device for Intracranial Aneurysms: A Multicenter Cohort Study.

OBJECTIVE: To examine outcomes of Pipeline embolization device (PED) use for treatment of intracranial aneurysms outside of U.S. Food and Drug Administration-approved indications. METHODS: Data from patients with aneurysms treated with off-label use of PED were pooled from 4 centers in a retrospective multicenter cohort study. Primary endpoints were decline in modified Rankin Scale score by at least 1 point and angiographic aneurysm occlusion at follow-up. RESULTS: The study cohort comprised 109 patients. Mean aneurysm size was 8.4 ± 7.4 mm, 20.2% of aneurysms were located in the posterior circulation, and 11.9% of aneurysms were ruptured. The most common reasons for off-label use were aneurysm size (50.5%), aneurysm location (25.7%), and both size and location (10.1%). Mean follow-up was 9 months. Complete occlusion was achieved in 82.5% of cases at last angiographic follow-up. Modified Rankin Scale score decline was found in 18.8% of cases. On univariate analysis, age, aneurysm size, aneurysm morphology, aneurysm location, reason for off-label use, and rupture status were not associated with clinical decline or aneurysm occlusion on angiography. On multivariate analysis, treatment of a ruptured aneurysm with PED was found to be an independent predictor of postoperative decline in modified Rankin Scale score, and size as the only reason for off-label PED use was found to be an independent predictor of complete occlusion on final angiography. CONCLUSIONS: Off-label use of PED has a reasonable risk-to-benefit profile for appropriately selected aneurysms. Posterior circulation location and fusiform morphology do not appear to be associated with worse clinical or angiographic outcomes.

Assessment of the Interrater Reliability of the Congress of Neurological Surgeons Microanastomosis Assessment Scale.

BACKGROUND: The potential for simulation-based learning in neurosurgical training has led the Congress of Neurosurgical Surgeons to develop a series of simulation modules. The Northwestern Objective Microanastomosis Assessment Tool (NOMAT) was created as the corresponding assessment tool for the Congress of Neurosurgical Surgeons Microanastomosis Module. The face and construct validity of the NOMAT have been previously established. OBJECTIVE: To further validate the NOMAT by determining its interrater reliability (IRR) between raters of varying levels of microsurgical expertise. METHODS: The NOMAT was used to assess residents' performance in a microanastomosis simulation module in 2 settings: Northwestern University and the Society of Neurological Surgeons 2014 Boot Camp at the University of Indiana. At Northwestern University, participants were scored by 2 experienced microsurgeons. At the University of Indiana, participants were scored by 2 postdoctoral fellows and an experienced microsurgeon. The IRR of NOMAT was estimated by computing the intraclass correlation coefficient using SPSS v22.0 (IBM, Armonk, New York). RESULTS: A total of 75 residents were assessed. At Northwestern University, 21 residents each performed microanastomosis on 2 model vessels of different sizes, one 3 mm and one 1 mm. At the University of Indiana, 54 residents performed a single microanastomosis procedure on 3-mm vessels. The intraclass correlation coefficient of the total NOMAT scores was 0.88 at Northwestern University and 0.78 at the University of Indiana. CONCLUSION: This study indicates high IRR for the NOMAT. These results suggest that the use of raters with varying levels of expertise does not compromise the precision or validity of the scale. This allows for a wider adoption of the scale and, hence, a greater potential educational impact.

Is forgoing chemical venous thromboembolism prophylaxis for women undergoing breast-conserving surgery for breast cancer safe?

BACKGROUND: Cancer patients have a 4 to 7 fold increased risk of venous thromboembolism (VTE) vs the normal population. Chest guidelines recommend no chemical VTE prophylaxis for women with a <1.5% risk for VTE. Although the risk of VTE among women undergoing breast-conserving therapy is reported to be low overall, the rate without chemical prophylaxis has not been defined. The objective of the study was to establish the VTE risk among women undergoing breast-conserving surgery (BCS) who did not receive chemical VTE prophylaxis. METHODS: From a prospective breast cancer database, 1,000 consecutive patients who underwent BCS without chemical VTE prophylaxis and with mechanical prophylaxis (support hose and intermittent pneumatic compression devices) were analyzed for VTE occurrence within 30 days postoperatively. Institutional review board approval was obtained. RESULTS: The mean age was 65.4 ± 11.7 years, and mean body mass index was 27.3 ± 5.7. About 81.9% of the patients were postmenopausal. Median tumor size was 1.1 cm, and 24.7% of patients had lymph node metastases. The 30-day rate of clinically significant VTE was 0% (95% CI 0% to .37%). Hematomas requiring surgical intervention occurred among .6% of patients. CONCLUSIONS: This cohort demonstrates that breast cancer patients undergoing BCS may be safely managed without chemical VTE prophylaxis because the risk with only mechanical prophylaxis is acceptable.

Use of a harvested radial artery graft with preservation of the vena comitantes to reduce spasm risk and improve graft patency for extracranial to intracranial bypass: Technical note.

BACKGROUND AND SIGNIFICANCE: The vessels of choice for cerebrovascular high-flow direct bypass procedures are the radial artery and the saphenous vein. Radial artery grafts have become favored over saphenous vein grafts because of higher patency rates and better size matching to appropriate recipient vessels. Radial grafts are prone to spasm however, and this may be seen in 4-10% of cases and can be associated with ischemic sequelae. The standard technique for radial artery harvest calls for complete separation of the artery from its adventitial attachments and associated venous network. There is reason to believe that this could contribute to spasm risk and possibly even thrombosis. Radial graft outcomes appear to be improved when the vena comitantes is preserved in cardiac and peripheral applications. We report the novel use of a harvested radial artery graft with preservation of its venae comitantes for extracranial to intracranial bypass. CLINICAL PRESENTATION: The patient is a 59-year-old male who had a blunt head trauma with associated loss of consciousness and who was led to the incidental discovery of a large fusiform middle cerebral artery (MCA) aneurysm. CONCLUSION: Preservation of the vena comitantes when harvesting a radial arterial graft for bypass, along with dual (arterial and venous) anastomoses, and concomitant use of intra-operative vaso-dilatory maneuvers to prevent spasm, may improve overall graft patency and patient outcome.