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Objective Surgical techniques to achieve complete resection of mesial–basal temporal tumors should be pursued by neurosurgical oncologists. We describe the anatomical subpial amygdalohippocampectomy (SpAH) technique for tumor resection. Methods The key anatomical landmarks and critical steps of the SpAH technique were outlined and emphasized with medical illustrations and intraoperative photographs. The senior author's 90-day surgical outcomes with this approach were reviewed. Results Twenty-five patients (men, 17 [68%]; women, 8 [32%]; median [range] age, 59 [23–80] years) with temporal tumors involving the amygdalohippocampal region were included. SpAH was performed selectively in 8 [32%] patients, whereas 17 [68%] patients underwent SpAH in conjunction with an anterior temporal lobectomy due to tumor involvement of the anterolateral temporal cortex. The subpial resection of the amygdala protected the critical structures of the suprasellar cistern and sylvian fissure. Identifying the choroidal fissure as the superior-most aspect of hippocampal resection protected the optic tract and the thalamus. Subpial resection of the parahippocampal gyrus inferiorly protected the brainstem and critical structures of the ambient cistern. Tumors in the amygdalohippocampal region were anatomically and completely resected in all 25 patients. Of the 15 patients who presented with seizures, 13 (87%) were seizure-free at the 90-day postsurgical follow-up. Permanent neurologic deficits occurred in 3 patients (12%). Conclusions The SpAH technique permits complete resection of mesial–basal temporal tumors with an acceptable morbidity profile. An in-depth understanding of temporal lobe anatomy combined with a refined microsurgical technique allows for reproducible resection of tumor in the amygdalohippocampal region while protecting critical neurovascular structures.

Objective Patients undergoing frontal lobectomy demonstrate lower seizure-freedom rates than patients undergoing temporal lobectomy and several other resective interventions. We attempted to utilize automated preoperative quantitative analysis of focal and global cortical volume loss to develop predictive volumetric indicators of seizure outcome after frontal lobectomy. Methods Ninety patients who underwent frontal lobectomy were stratified based on seizure freedom at a mean follow-up time of 3.5 (standard deviation [SD] 2.5) years. Automated quantitative analysis of cortical volume loss organized by distinct brain region and laterality was performed on preoperative T1-weighted magnetic resonance imaging (MRI) studies. Univariate statistical analysis was used to select potential predictors of seizure freedom. Backward variable selection and multivariate logistical regression were used to develop models to predict seizure freedom. Results Forty-eight of 90 (53.3%) patients were seizure-free at the last follow-up. Several frontal and extrafrontal brain regions demonstrated statistically significant differences in both volumetric cortical volume loss and volumetric asymmetry between the left and right sides in the seizure-free and non-seizure-free cohorts. A final multivariate logistic model utilizing only preoperative quantitative MRI data to predict seizure outcome was developed with a c-statistic of 0.846. Using both preoperative quantitative MRI data and previously validated clinical predictors of seizure outcomes, we developed a model with a c-statistic of 0.897. Significance This study demonstrates that preoperative cortical volume loss in both frontal and extrafrontal regions can be predictive of seizure outcome after frontal lobectomy, and models can be developed with excellent predictive capabilities using preoperative MRI data. Automated quantitative MRI analysis can be quickly and reliably performed in patients with frontal lobe epilepsy, and further studies may be developed for integration into preoperative risk stratification.

BACKGROUND: The COVID-19 pandemic has significantly affected patient care across specialties. Ramifications for neurosurgery include substantial disruptions to surgical training and changes in nonurgent patient presentations to the emergency department. This study quantifies the effects of the COVID-19 pandemic on the number of emergency department patients who were referred to the neurosurgery department for further consultation and treatment and identifies and describes trends in the characteristics of these visits. METHODS: A retrospective review was performed of neurosurgical consultations at a single high-volume institution for 28 call-day periods before and after the official announcement of the pandemic. Primary outcomes included consultations per call-day, patient presentation category, and patient admission. RESULTS: The neurosurgical service was consulted regarding 629 patients (367 male patients) during the study period, with 471 (75%) and 158 (25%) patients presenting before and after the announcement of the COVID-19 pandemic, respectively. The mean number of neurosurgical consultations per call-day was significantly lower in the COVID-19 period (5.6 consultations) compared with the pre-COVID-19 period (16.8 consultations) (P < 0.001). After adjusting for patient demographics, the rate of presentation for general nonurgent concerns, such as back pain, headaches, and other general weaknesses, significantly decreased (odds ratio [95% confidence interval], 0.60 [0.47-0.77], P < 0.001). CONCLUSIONS: Neurosurgical consultations significantly decreased after the onset of the COVID-19 pandemic, with a substantially lower overall number of consultations necessitating operative interventions. Furthermore, the relative number of patients with nonemergent neurological conditions significantly decreased during the pandemic.

Treatment of small ruptured aneurysms (SRAs) remains controversial, with literature reporting difficulty with endovascular versus microsurgical approaches. This paper analyzes outcomes after endovascular coiling and microsurgical clipping among patients with SRAs prospectively enrolled in the Barrow Ruptured Aneurysm Trial (BRAT). All BRAT patients were included in this study. Patient demographics, aneurysm size, aneurysm characteristics, procedure-related complications, and outcomes at discharge and at 1-year and 6-year follow-up were evaluated. A modified Rankin scale (mRS) score > 2 was considered a poor outcome. Of 73 patients with SRAs, 40 were initially randomly assigned to endovascular coiling and 33 to microsurgical clipping. The rate of treatment crossover was significantly different between coiling and clipping; 25 patients who were assigned to coiling crossed over to clipping, and no clipping patients crossed over to coiling (P 2) at discharge and 1-year and 6-year follow-up (P = 0.48 and 0.73, respectively). Most SRA patients in the BRAT underwent surgical clipping, with a high rate of crossover from endovascular approaches. Endovascular treatment was equivalent to surgical clipping with regard to procedure-related complications and neurologic outcomes.

Aneurysmal subarachnoid hemorrhage (aSAH) is debilitating in elderly patients, but literature regarding this population is scarce, and clinical decision-making remains debated. Outcomes of elderly patients with aSAH stratified by age and clinical presentation were analyzed.Patients treated for aSAH were retrospectively analyzed. Patients were trichotomized into a young cohort (aged60 years [n = 268]) and 2 elderly cohorts (aged 60-65 years [n = 60] and ≥65 years [n = 77]). The elderly cohorts were analyzed by poor or good scores at presentation (Hunt and Hess [HH] score3 vs. ≤3, respectively) and poor functional outcome (modified Rankin Scale score2).Of 137 elderly patients, 121 had a 6-year follow-up. The65-year-olds (75% [52/69]) were more likely to have poor functional outcomes than the 60 to 65-year-olds (48% [25/52]) (odds ratio, 3.3; 95% confidence interval, 1.5-7.1; P = 0.002). Among those with an HH score ≤3 at presentation (n = 90), the65-year-old cohort had poorer outcomes than the 60 to 65-year-old cohort at 6-year follow-up (69% [35/51] vs. 36% [14/39], respectively; odds ratio, 3.9; 95% confidence interval, 1.6-9.4; P = 0.003). Among patients with an HH score3, no statistically significant differences in functional outcome were observed between the65-year-old (n = 18) and 60 to 65-year-old (n = 13) cohorts.Elderly patients with aSAH are at high risk for poor functional outcomes. However, among those presenting with good HH scores, younger-elderly patients (aged 60-65 years) tend to fare better than older-elderly patients (aged65 years). Elderly patients presenting with high-grade aSAH fare poorly regardless of age, which can inform clinical decision-making and prognostication.

Objective Epilepsy with periventricular nodular heterotopia (PVNH) lacks a conclusive surgical treatment strategy as eloquent cortex and important white matter tracts frequently overlay the deep periventricular nodules. Our goal was to evaluate the safety and efficacy of laser interstitial thermal therapy (LITT) for the treatment of epilepsy in PVNH. Methods Data on demographic characteristics, complications, visual outcomes, Engel classification at last follow-up, antiepileptic drug use, morbidity, and mortality among patients who underwent this procedure were retrospectively reviewed. Results Between May 2015 and January 2019, 5 patients underwent 6 LITT procedures for epilepsy with PVNH. One patient had residual nodules after their first procedure and underwent a second ablation. The average follow-up time was 12 months. Three patients were Engel class Ia, 1 patient was Engel class II, and 1 patient was Engel class III at last follow-up. Two patients were able to reduce their antiepileptic drugs postoperatively. Three patients had no changes in vision, 1 patient experienced a quadrantanopsia, and 1 patient had subjective blurry vision after their procedures. No patients experienced motor deficits, dysphasia, infection, or mortality. Conclusions LITT appears to be a safe and promising option to provide seizure relief for patients with refractory epilepsy and PVNH that otherwise may not be surgical candidates. Some appropriately determined patients with refractory epilepsy may benefit from LITT before proceeding with an invasive intracranial evaluation. A larger sample size and long-term follow-up is necessary to further elucidate safety and efficacy.

Objective In ventriculoperitoneal shunt (VPS) placement, distal placement of the peritoneal catheter will typically be performed by a neurosurgeon. More recently, laparoscopic-assisted (LA) placement of the distal peritoneal catheter by general surgeons has become common. The present study examined whether LA placement of a VPS (LAVPS) is associated with a reduced operative time, lower hospital costs, and fewer distal revisions. Methods A retrospective review was performed of the data from all patients who had received a new VPS at our institution from 2013 to 2016. Age, sex, diagnosis, previous abdominal surgery, operative time, anesthesia grade, incidence of 30-day shunt failure, and total hospital charges were analyzed. Results A total of 680 patients had undergone first-time VPS placement, including 199 with LAVPS and 481 with non–LAVPS placement (non-LAVPS). The mean age of the LAVPS patients was significantly older than that of the non-LAVPS patients (64.1 vs. 59.3 years; P = 0.002). The mean operative time was shorter in the LAVPS group than in the non-LAVPS group (55 vs. 75 minutes; P Conclusions Compared with non-LAVPS, LAVPS was associated with significantly shorter operative times and fewer distal shunt revisions within 30 days. The findings from a subset analysis supported a decrease in total hospital charges. Additional studies are needed; however, these data suggest that LAVPS is a safer, less-expensive alternative to non-LAVPS.

Skull base paragangliomas are highly vascular tumors that are often embolized before surgical resection; however, the safety and efficacy of preoperative embolization using an ethylene vinyl alcohol copolymer (Onyx; Medtronic, Dublin, Republic of Ireland) in these tumors is unknown. This retrospective cohort study evaluated patient outcomes after preoperative embolization of skull base paragangliomas using Onyx. We retrospectively analyzed data from all patients with skull base paragangliomas who underwent preoperative Onyx embolization at our institution (January 01, 2005–December 31, 2017). Patient, tumor, embolization, and outcomes data were extracted by reviewing inpatient and outpatient clinical and imaging records. Seven patients were studied (5/7 [71%] female), 6 with glomus jugulares and 1 with a glomus vagale. The median age was 52 years, and the most common presenting symptom was cranial neuropathy (6/7 [86%]). The tumor vascular supply was from the ascending pharyngeal artery in all 7 cases (100%) with additional feeders including the occipital artery in 5 (71%); internal carotid artery in 3 (43%); middle meningeal, vertebral, and internal maxillary artery each in 2 (29%); and posterior auricular artery in 1 (14%). The median postembolization tumor devascularization was 80% (range, 64–95%). The only postembolization complication was a facial palsy in 1 patient. Preoperative embolization with Onyx affords excellent devascularization for the majority of skull base paragangliomas, and it may facilitate resection of these hypervascular lesions. The advantages provided by Onyx with respect to penetration of intratumoral vessels must be weighed against the risk of cranial neuropathy.

Background Stereoelectroencephalography (SEEG) is a commonly used technique for mapping the epileptogenic zone before epilepsy surgery. Many SEEG depth electrode implantation techniques involve the use of extensive technological equipment and shaving of the patient's entire head before electrode implantation. Our goal was to evaluate an SEEG depth electrode implantation technique that used readily available cost-effective neurosurgical equipment, was minimally invasive in nature, and required negligible hair shaving. Methods Data on demographic characteristics, operative time, hemorrhagic complications, implantation complications, infection, morbidity, and mortality among patients who underwent this procedure were reviewed retrospectively. Results Between April 2016 and March 2018, 23 patients underwent implantation of 213 depth electrodes with use of this technique. Mean (SD) operative time was 123 (32) minutes (range, 66–181 minutes). A mean (SD) of 9.3 (1.4) electrodes were placed for each patient (range, 8–13 electrodes). Two of the 213 electrodes (0.9%) were associated with postimplantation asymptomatic hemorrhage. One of the 213 electrodes (0.5%) was placed extradurally or incorrectly. None of the 213 electrodes was associated with symptomatic complications. No patients experienced infectious complications at any point in the preoperative, perioperative, or postoperative stages. Conclusions This minimally invasive, cost-effective technique for SEEG depth electrode implantation is a safe, efficient method that uses readily available basic neurosurgical equipment. This technique may be useful in neurosurgery centers with more limited resources. This study suggests that leaving the patient's hair largely intact throughout the procedure does not pose an additional infection risk.

Background Optimal management of patients with extracranial blunt cerebrovascular injury (BCVI) remains controversial, with both anticoagulation and antiplatelet therapy being recommended. The purpose of this study was to evaluate the efficacy and safety of using acetylsalicylic acid (ASA) in the management of BCVI. Methods Patients with BCVI were identified from the registry of a Level 1 trauma center between 2010 and 2017. Digital imaging and electronic medical records were reviewed for patient information including demographic characteristics, injury type, therapy, outcomes, and follow-up. Results Over the study period, 13,578 patients were admitted following blunt trauma, with 94 (0.7%) having confirmed BCVI (mean age, 42 years; 72% male). Mean Injury Severity Score and Glasgow Coma Score were 27 and 10, respectively. BCVI was identified in 130 vessels with Biffl grade I (38%) and grade II injury (29%) being most common. Twelve (13%) patients experienced an ischemic event, but only 3 events occurred after diagnosis. ASA was primary treatment for 56 (60%) patients. Thirty patients (32%) received no treatment; 21 patients died within 24 hours of primary injury. Only 4 patients had ASA contraindications. Four patients (7%) had ASA-related complications; there were 2 cases of intracranial hemorrhage progression and 2 cases of gastrointestinal bleeding. Follow-up vascular imaging at a mean of 36 days demonstrated stable or improved levels of BCVI in 94% of patients. Conclusions An ASA-based management strategy for BCVI was efficacious and relatively safe in this study. This approach may be the preferred treatment for BCVI, but confirmation is needed.

Traumatic brain injury (TBI) is associated with one-third of all deaths from trauma. Preinjury exposure to cardiovascular drugs may affect TBI outcomes. Angiotensin-converting enzyme inhibitors (ACEIs) exacerbate brain cell damage and worsen functional outcomes in the laboratory setting. β-blockers (BBs), however, appear to be associated with reduced mortality among patients with isolated TBI. Examine the association between preinjury ACEI and BB use and clinical outcome among patients with isolated TBI. A retrospective cohort study of patients age ≥ 40 years admitted to an academic level 1 trauma center with isolated TBI between January 2010 and December 2014 was performed. Isolated TBI was defined as a head Abbreviated Injury Scale (AIS) score ≥ 3, with chest, abdomen, and extremity AIS scores ≤ 2. Preinjury medication use was determined through chart review. All patients with concurrent BB use were initially excluded. In-hospital mortality was the primary measured outcome. Over the 5-year study period, 600 patients were identified with isolated TBI who were naive to BB use. There was significantly higher mortality (P = .04) among patients who received ACEI before injury (10 of 96; 10%) than among those who did not (25 of 504; 5%). A multivariate stepwise logistic regression analysis revealed a threefold increased risk of mortality in the ACEI cohort (P

External ventricular drains (EVDs) are often placed emergently for patients with hydrocephalus, which carries a risk of hemorrhage. Rarely, rupture of a pseudoaneurysm originating from an EVD placement precipitates such a hemorrhage. An EVD was placed in a patient with a ruptured left posterior communicating artery aneurysm who later underwent endovascular coil embolization. On post-bleed day 20, a distal right anterior cerebral artery pseudoaneurysm along the EVD tract ruptured, which was successfully treated via clip-wrapping. Although EVD-associated pseudoaneurysms are rare, they have a high propensity for rupture. Early treatment of these lesions should be considered to prevent neurologic deterioration.

Objective Postoperative peri-lead edema (PLE) is a poorly understood complication of deep brain stimulation (DBS), which has been described sporadically in patients presenting with profound and often delayed symptoms. We performed a prospective evaluation of patients undergoing DBS to determine the frequency of and identify risk factors for PLE. Methods Patients underwent DBS electrode placement by a single physician. Postoperative magnetic resonance imaging (MRI) was performed approximately 6 weeks after the operation in asymptomatic subjects and analyzed for presence of PLE. All symptomatic subjects underwent MRI at the time of presentation. Data regarding index disease, preoperative medical issues, operative technique, and intraoperative variables were collected and statistically analyzed. Results A total of 191 leads were placed in 102 subjects; 15 patients (14.7%) demonstrated PLE. Seven patients (6.9%) presented with symptoms related to PLE, most often altered mental status or neurologic deficit. Many of the MRI findings were profound, with PLE sometimes several centimeters in diameter. No statistically significant difference was found between PLE-positive and normal subjects when analyzing multiple variables, including presence of vascular disease, hypertension, anticoagulant/antiplatelet use, electrode target, index disease, unilateral versus bilateral lead placement, number of brain penetrations, and presence or absence of microelectrode recording. Conclusions Patients with postoperative PLE can present with severe symptoms or can be asymptomatic and go undiagnosed. Because of the delayed-onset potential, PLE may be more common than previously reported. No clear risk factors have been identified; therefore, further studies and increased clinical vigilance are paramount for improving comprehension and possible prevention of PLE.

OBJECTIVEMinimally invasive anterolateral retroperitoneal approaches for lumbar interbody arthrodesis have distinct advantages attractive to spine surgeons. Prepsoas or transpsoas trajectories can be employed with differing complication profiles because of the inherent anatomical differences encountered in each approach. The evidence comparing them remains limited because of poor quality data. Here, the authors sought to systematically review the available literature and perform a meta-analysis comparing the two techniques.METHODSA systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A database search was used to identify eligible studies. Prepsoas and transpsoas studies were compiled, and each study was assessed for inclusion criteria. Complication rates were recorded and compared between approach groups. Studies incorporating an analysis of postoperative subsidence and pseudarthrosis rates were also assessed and compared.RESULTSFor the prepsoas studies, 20 studies for the complications analysis and 8 studies for the pseudarthrosis outcomes analysis were included. For the transpsoas studies, 39 studies for the complications analysis and 19 studies for the pseudarthrosis outcomes analysis were included. For the complications analysis, 1874 patients treated via the prepsoas approach and 4607 treated with the transpsoas approach were included. In the transpsoas group, there was a higher rate of transient sensory symptoms (21.7% vs 8.7%, p = 0.002), transient hip flexor weakness (19.7% vs 5.7%, p < 0.001), and permanent neurological weakness (2.8% vs 1.0%, p = 0.005). A higher rate of sympathetic nerve injury was seen in the prepsoas group (5.4% vs 0.0%, p = 0.03). Of the nonneurological complications, major vascular injury was significantly higher in the prepsoas approach (1.8% vs 0.4%, p = 0.01). There was no difference in urological or peritoneal/bowel injury, postoperative ileus, or hematomas (all p > 0.05). A higher infection rate was noted for the transpsoas group (3.1% vs 1.1%, p = 0.01). With regard to postoperative fusion outcomes, similar rates of subsidence (12.2% prepsoas vs 13.8% transpsoas, p = 0.78) and pseudarthrosis (9.9% vs 7.5%, respectively, p = 0.57) were seen between the groups at the last follow-up.CONCLUSIONSComplication rates vary for the prepsoas and transpsoas approaches owing to the variable retroperitoneal anatomy encountered during surgical dissection. While the risks of a lasting motor deficit and transient sensory disturbances are higher for the transpsoas approach, there is a reciprocal reduction in the risks of major vascular injury and sympathetic nerve injury. These results can facilitate informed decision-making and tailored surgical planning regarding the choice of minimally invasive anterolateral access to the spine.

Microsurgical clipping of large paraclinoid aneurysms is challenging because of the complex anatomy of the dural rings, lack of easy proximal control, and wide aneurysm necks. Proximal retrograde suction decompression, or the Dallas technique, can reduce aneurysm turgor and, with aspiration of the trapped cervical and supraclinoid internal carotid arteries (ICAs), can collapse the aneurysm to aid microsurgical clipping.(1-5) A woman in her late 30s presented with decreased right-eye visual acuity. Informed written consent was obtained for microsurgical management and publication. Upon cervical exposure of the carotid bifurcation, we performed a standard pterional craniotomy, trans-sylvian exposure, and intradural anterior clinoidectomy. After burst suppression and cross-clamping of the carotid, we inserted an angiocatheter at the common carotid artery (CCA). Distal temporary clips were placed on the posterior communicating artery and C7 ICA. With the cervical ICA unclamped, retrograde suction was continuously applied to deflate the aneurysm. We applied 2 pairs of fenestrated-booster clips to the aneurysm dome and a fifth clip to the aneurysm neck. After restoration of flow, indocyanine green angiography and Doppler assessments were performed. The proximal clip was converted into a curved clip to optimize ICA flow. Postoperative angiography confirmed complete occlusion of the aneurysm. The patient was discharged on postoperative day 3, with stable visual acuity.(6) This video demonstrates that retrograde suction decompression via the cervical CCA can be safely performed to facilitate clipping of complex paraclinoid ICA aneurysms. Comprehensive planning of temporary aneurysm trapping for suction decompression and permanent clip construct for aneurysm occlusion are needed for effective aneurysm repair.

Background Stereoelectroencephalography (SEEG) is used to identify the epileptogenic zone (EZ) in patients with epilepsy for potential surgical intervention. Occasionally, the EZ is difficult to localize even after an SEEG implantation. Objective To demonstrate a safe technique for placing additional electrodes in ongoing SEEG evaluations. Describe efficacy, complications, and surgical outcomes. Methods An operative technique which involves maintaining previously placed electrodes and sterilely placing new electrodes was developed and implemented. All patients who underwent placement of additional SEEG electrodes during the same admission were retrospectively reviewed. Results A total of 14 patients met criteria and had undergone SEEG evaluation with 198 electrodes implanted. A total 93% of patients (13/14) had nonlesional epilepsy. After unsuccessful localization of the EZ after a mean of 9.6 d of monitoring, each patient underwent additional placement of electrodes (5.5 average electrodes per patient) to augment the original implantation. At no point did any patients develop new hemorrhage, infection, wound breakdown, or require any kind of additional antimicrobial treatment. A total 64% (9/14) of patients were able to undergo surgery aimed at removing the EZ guided by the additional SEEG electrodes. A total 44% (4/9) of surgical patients had Engel class I outcomes at an average follow-up time of 11 mo. Conclusion Placing additional SEEG electrodes, while maintaining the previously placed electrodes, appears to be safe, effective, and had no infectious complications. When confronted with difficult-to-localize epilepsy even after invasive monitoring, it appears to be safe and potentially clinically effective to place additional electrodes during the same admission.

Background Spetzler Martin (SM) grade 3 arteriovenous malformations (AVMs) are challenging lesions, often treated with preoperative embolization before definitive microsurgical resection. However, no significant difference in outcomes has been reported in patients with preoperative embolization for these lesions. Objective To compare neurological outcomes of microsurgically treated SM grade 3 AVMs with vs without preoperative resection. Methods A retrospective analysis of prospectively collected AVM databases from two large tertiary centers for all microsurgically treated SM grade 3 AVMs during 2011–2018 was performed. Comparison of neurological outcome (modified Rankin Scale score [mRS] >2 and change in mRS on last follow-up) between patients with vs without preoperative embolization was performed. Results Of 102 patients with microsurgically treated SM grade 3 AVMs, 57 (56%) underwent preoperative embolization. Significant differences between patients with vs without embolization were found for eloquence (75% vs 93%, p=0.02), diameter ≥3 cm (53% vs 27%, p=0.01), diffuseness (7% vs 22%, p=0.04), and mean follow-up mRS (1.1 vs 2.0, p=0.005). A higher percentage of patients without embolization (38%) than with embolization (7%) had an mRS >2 on follow-up (p 2. Conclusion Lack of preoperative embolization in SM grade 3 AVMs may be associated with increased risk of poor outcome following microsurgical resection. Hence, evaluation for preoperative embolization is essential for all intermediate-grade lesions. Disclosures J. Catapano: None. F. Frisoli: None. C. Nguyen: None. D. Wilkinson: None. N. Majmundar: None. T. Cole: None. J. Baranoski: None. A. Whiting: None. H. Kim: None. R. Spetzler: None. A. Ducruet: None. F. Albuquerque: None. M. Lawton: None.

OBJECTIVE An advantage of lateral lumbar interbody fusion (LLIF) surgery is the indirect decompression of the neural elements that occurs because of the resulting disc height restoration, spinal realignment, and ligamentotaxis. The degree to which indirect decompression occurs varies; no method exists for effectively predicting which patients will respond. In this study, the authors identify preoperative predictive factors of indirect decompression of the central canal. METHODS The authors performed a retrospective evaluation of prospectively collected consecutive patients at a single institution who were treated with LLIF without direct decompression. Preoperative and postoperative MRI was used to grade central canal stenosis, and 3D volumetric reconstructions were used to measure changes in the central canal area (CCA). Multivariate regression was used to identify predictive variables correlated with radiographic increases in the CCA and clinically successful improvement in visual analog scale (VAS) leg pain scores. RESULTS One hundred seven levels were treated in 73 patients (mean age 68 years). The CCA increased 54% from a mean of 0.96 cm2 to a mean of 1.49 cm2 (p < 0.001). Increases in anterior disc height (74%), posterior disc height (81%), right (25%) and left (22%) foraminal heights, and right (12%) and left (15%) foraminal widths, and reduction of spondylolisthesis (67%) (all p < 0.001) were noted. Multivariate evaluation of predictive variables identified that preoperative spondylolisthesis (p < 0.001), reduced posterior disc height (p = 0.004), and lower body mass index (p = 0.042) were independently associated with radiographic increase in the CCA. Thirty-two patients were treated at a single level and had moderate or severe central stenosis preoperatively. Significant improvements in Oswestry Disability Index and VAS back and leg pain scores were seen in these patients (all p < 0.05). Twenty-five (78%) patients achieved the minimum clinically important difference in VAS leg pain scores, with only 2 (6%) patients requiring direct decompression postoperatively due to persistent symptoms and stenosis. Only increased anterior disc height was predictive of clinical failure to achieve the minimum clinically important difference. CONCLUSIONS LLIF successfully achieves indirect decompression of the CCA, even in patients with substantial central stenosis. Low body mass index, preoperative spondylolisthesis, and disc height collapse appear to be most predictive of successful indirect decompression. Patients with preserved disc height but severe preoperative stenosis are at higher risk of failure to improve clinically.

BackgroundSpetzler-Martin (SM) grade III arteriovenous malformations (AVMs) are at the boundary of safe operability, and preoperative embolization may reduce surgical risks.ObjectiveTo evaluate the benefits of preoperative AVM embolization by comparing neurological outcomes in patients with grade III AVMs treated with or without preoperative embolization.MethodsAll microsurgically treated grade III AVMs were identified from 2011 to 2018 at 2 medical centers. Neurological outcomes, measured as final modified Rankin Scale scores (mRS) and changes in mRS from preoperative baseline to last follow-up evaluation, were compared in patients with and without preoperative embolization.ResultsOf the 102 patients with grade III AVMs who were treated microsurgically, 57 (56%) underwent preoperative embolization. Significant differences were found between the patients with and without embolization in AVM eloquence (74% vs 93%, P=.02), size≥3cm (47% vs 73%, P=.01), diffuseness (7% vs 22%, P=.04), and mean final mRS (1.1 vs 2.0, P=.005). Poor outcomes were more frequent in patients without embolization (38%) than with embolization (7%) (final mRS>2; P2; odds ratio, 4.2; 95% CI, 1.1-16; P=.03).ConclusionNonembolization of SM grade III AVMs is associated with an increased risk of poor neurological outcomes after microsurgical resection. Preoperative embolization of intermediate-grade AVMs selected because of large AVM size, surgical inaccessibility of feeding arteries, and high flow should be employed more often than anticipated, even in the context of increasing microsurgical experience with AVMs.

OBJECTIVETakotsubo cardiomyopathy (TC) in patients with aneurysmal subarachnoid hemorrhage (aSAH) is associated with high morbidity and mortality. Previous studies have shown that female patients presenting with a poor clinical grade are at the greatest risk for developing TC. Intra-aortic balloon pumps (IABPs) are known to support cardiac function in severe cases of TC, and they may aid in the treatment of vasospasm in these patients. In this study, the authors investigated risk factors for developing TC in the setting of aSAH and outcomes among patients requiring IABPs.METHODSThe authors retrospectively reviewed the records of 1096 patients who had presented to their institution with aSAH. Four hundred five of these patients were originally enrolled in the Barrow Ruptured Aneurysm Trial, and an additional 691 patients from a subsequent prospectively maintained aSAH database were analyzed. Medical records were reviewed for the presence of TC according to the modified Mayo Clinic criteria. Outcomes were determined at the last follow-up, with a poor outcome defined as a modified Rankin Scale (mRS) score > 2.RESULTSTC was identified in 26 patients with aSAH. Stepwise multivariate logistic regression analysis identified female sex (OR 8.2, p = 0.005), Hunt and Hess grade > III (OR 7.6, p < 0.001), aneurysm size > 7 mm (OR 3, p = 0.011), and clinical vasospasm (OR 2.9, p = 0.037) as risk factors for developing TC in the setting of aSAH. TC patients, even with IABP placement, had higher rates of poor outcomes (77% vs 47% with an mRS score > 2, p = 0.004) and mortality at the last follow-up (27% vs 11%, p = 0.018) than the non-TC patients. However, aggressive intra-arterial endovascular treatment for vasospasm was associated with good outcomes in the TC patients versus nonaggressive treatment (100% with mRS ≤ 2 at last follow-up vs 53% with mRS > 2, p = 0.040).CONCLUSIONSTC after aSAH tends to occur in female patients with large aneurysms, poor clinical grades, and clinical vasospasm. These patients have significantly higher rates of poor neurological outcomes, even with the placement of an IABP. However, aggressive intra-arterial endovascular therapy in select patients with vasospasm may improve outcome.

Invasive neuromonitoring is an important component of presurgical workup and seizure onset zone localization in patients with epilepsy being considered for surgical resection. In the United States, intraparenchymal stereoelectroencephalography (SEEG) electrodes have been replacing subdural grid electrodes for most cases, following a trend that has already matured in Europe. The use of robotic assistance has been shown to improve operative times and accuracy in SEEG electrode placement, as users benefit from the embedded planning software as well as the efficiency and accuracy of the robotic arm. The greatest barriers to implementation of this technology are the upfront cost and learning curve. This case-based surgeon's perspective operative video could benefit those considering incorporating robotic assistance for SEEG electrode placement. Those considering robotic assistance for pedicle screw placement and other budding applications may also benefit, as well as innovators looking for new applications. The patient consented for the procedure, video recording, and inclusion in subsequent publications.

Objective To use reliable change indices (RCIs) developed specifically for pediatric patients with epilepsy to examine cognitive outcomes after frontal lobe resection for pharmacoresistant epilepsy. Methods Forty-one pediatric patients (25 male, Mage = 10 years) completed comprehensive neuropsychological evaluations before and an average of 6.5 months after frontal lobe resections for treatment of epilepsy. Evaluations included tests of intelligence, attention/working memory, processing speed, language, visuospatial skills, executive function, and episodic memory. Practice effect-adjusted RCIs were used to determine clinically significant postoperative cognitive change. Demographic, disease, and surgical variables were examined to identify factors associated with postoperative cognitive decline or improvement. Results Within each cognitive domain, there was a large proportion of patients (51–84%) who did not exhibit significant cognitive change. In terms of overall cognitive profile, 44% demonstrated improvement in at least one domain and 69% declined in at least one domain. Postoperative cognitive improvement occurred most commonly in the domain of processing speed, whereas postoperative cognitive decline occurred most frequently in the domain of visuospatial skills. Younger age at surgery was associated with cognitive improvement. Older age at seizure onset and higher baseline cognitive performance were associated with cognitive decline. Significance Approximately 6.5 months after frontal lobe resection, only 15% of our sample showed stable performance across all cognitive domains. Seventeen percent of patients showed improvements without declines, 42% showed declines without improvements, and 27% showed a mix of improvements and declines across different cognitive domains. Age and baseline abilities were associated with postoperative cognitive change on multiple measures. With 1 in 8 children demonstrating postoperative decline across three or more domains, further research is needed to identify factors associated with cognitive decline in order to inform clinical decision-making and patient/family counseling.

OBJECTIVEThe SAFIRE grading scale is a novel, computable scale that predicts the outcome of aneurysmal subarachnoid hemorrhage (aSAH) patients in acute follow-up. However, this scale also may have prognostic significance in long-term follow-up and help guide further management.METHODSThe records of all patients enrolled in the Barrow Ruptured Aneurysm Trial (BRAT) were retrospectively reviewed, and the patients were assigned SAFIRE grades. Outcomes at 1 year and 6 years post-aSAH were analyzed for each SAFIRE grade level, with a poor outcome defined as a modified Rankin Scale score > 2. Univariate analysis was performed for patients with a high SAFIRE grade (IV or V) for odds of poor outcome at the 1- and 6-year follow-ups.RESULTSA total of 405 patients with confirmed aSAH enrolled in the BRAT were analyzed; 357 patients had 1-year follow-up, and 333 patients had 6-year follow-up data available. Generally, as the SAFIRE grade increased, so did the proportion of patients with poor outcomes. At the 1-year follow-up, 18% (17/93) of grade I patients, 22% (20/92) of grade II patients, 32% (26/80) of grade III patients, 43% (38/88) of grade IV patients, and 75% (3/4) of grade V patients were found to have poor outcomes. At the 6-year follow-up, 29% (23/79) of grade I patients, 24% (21/89) of grade II patients, 38% (29/77) of grade III patients, 60% (50/84) of grade IV patients, and 100% (4/4) of grade V patients were found to have poor outcomes. Univariate analysis showed that a SAFIRE grade of IV or V was associated with a significantly increased risk of a poor outcome at both the 1-year (OR 2.5, 95% CI 1.5–4.2; p < 0.001) and 6-year (OR 3.7, 95% CI 2.2–6.2; p < 0.001) follow-ups.CONCLUSIONSHigh SAFIRE grades are associated with an increased risk of a poor recovery at late follow-up.

OBJECTIVE Debate continues over proper surgical treatment for mesial temporal lobe epilepsy (MTLE). Few large comprehensive studies exist that have examined outcomes for the subtemporal selective amygdalohippocampectomy (sSAH) approach. This study describes a minimally invasive technique for sSAH and examines seizure and neuropsychological outcomes in a large series of patients who underwent sSAH for MTLE. METHODS Data for 152 patients (94 women, 61.8%; 58 men, 38.2%) who underwent sSAH performed by a single surgeon were retrospectively reviewed. The sSAH technique involves a small, minimally invasive opening and preserves the anterolateral temporal lobe and the temporal stem. RESULTS All patients in the study had at least 1 year of follow-up (mean [SD] 4.52 [2.57] years), of whom 57.9% (88/152) had Engel class I seizure outcomes. Of the patients with at least 2 years of follow-up (mean [SD] 5.2 [2.36] years), 56.5% (70/124) had Engel class I seizure outcomes. Preoperative and postoperative neuropsychological test results indicated no significant change in intelligence, verbal comprehension, perceptual reasoning, attention and processing, cognitive flexibility, visuospatial memory, or mood. There was a significant change in word retrieval regardless of the side of surgery and a significant change in verbal memory in patients who underwent dominant-side resection (p < 0.05). Complication rates were low, with a 1.3% (2/152) permanent morbidity rate and 0.0% mortality rate. CONCLUSIONS This study reports a large series of patients who have undergone sSAH, with a comprehensive presentation of a minimally invasive technique. The sSAH approach described in this study appears to be a safe, effective, minimally invasive technique for the treatment of MTLE.

Background Catheter-related infections are a potentially life-threatening complication of having an external ventricular drain (EVD). Patients with aneurysmal subarachnoid hemorrhage (aSAH) are at increased risk of infection associated with prolonged ventricular drainage, with a reported mean infection rate of 6%. We report the EVD-associated infection rate among patients with aSAH managed with a unique standardized treatment protocol without an occlusive EVD dressing. Methods Patients with aSAH admitted from August 2015 through August 2017 were retrospectively analyzed for EVD placement. Cerebrospinal fluid (CSF) samples were obtained twice weekly for culture and routine studies. EVD-associated infection was defined as growth of CSF cultures. Results During the 2-year study period, 122 patients presented with an aSAH, with 91 (74.6%) having EVD placement. In patients with EVDs, the mean age was 57.9 years (68% women); 88% of aSAHs were Fisher grade III or IV. Mean duration of EVD was 14 days, and 13% of patients required EVD replacement. Endovascular coiling and surgical clipping were performed in 34 (37%) and 53 (58%) patients with EVD, respectively. A total of 347 CSF studies were performed with no EVD-associated infections. There were 3 CSF samples with false-positive Gram stain results but no growth on concurrent or multiple repeat cultures. Conclusions Using a standardized protocol for placement and management of EVDs in patients with aSAH is associated with low risk of CSF infection. Our study demonstrates that occlusive EVD dressings are not necessary and that routine CSF sampling in patients with EVD may lead to false-positive findings and unnecessary antibiotic administration.

OBJECTIVELateral lumbar interbody fusion (LLIF) is a useful minimally invasive technique for achieving anterior interbody fusion and preserving or restoring lumbar lordosis. However, achieving circumferential fusion via posterior instrumentation after an LLIF can be challenging, requiring either repositioning the patient or placing pedicle screws in the lateral position. Here, the authors explore an alternative single-position approach: LLIF in the prone lateral (PL) position.METHODSA cadaveric feasibility study was performed using 2 human cadaveric specimens. A retrospective 2-center early clinical series was performed for patients who had undergone a minimally invasive lateral procedure in the prone position between August 2019 and March 2020. Case duration, retractor time, electrophysiological thresholds, implant size, screw accuracy, and complications were recorded. Early postoperative radiographic outcomes were reported.RESULTSA PL LLIF was successfully performed in 2 cadavers without causing injury to a vessel or the bowel. No intraoperative subsidence was observed. In the clinical series, 12 patients underwent attempted PL surgery, although 1 case was converted to standard lateral positioning. Thus, 11 patients successfully underwent PL LLIF (89%) across 14 levels: L2–3 (2 of 14 [14%]), L3–4 (6 of 14 [43%]), and L4–5 (6 of 14 [43%]). For the 11 PL patients, the mean (± SD) age was 61 ± 16 years, mean BMI was 25.8 ± 4.8, and mean retractor time per level was 15 ± 6 minutes with the longest retractor time at L2–3 and the shortest at L4–5. No intraoperative subsidence was noted on routine postoperative imaging.CONCLUSIONSPerforming single-position lateral transpsoas interbody fusion with the patient prone is anatomically feasible, and in an early clinical experience, it appeared safe and reproducible. Prone positioning for a lateral approach presents an exciting opportunity for streamlining surgical access to the lumbar spine and facilitating more efficient surgical solutions with potential clinical and economic advantages.

Anterior column realignment (ACR) with anterior longitudinal ligament (ALL) release from a lateral transpsoas approach is increasingly being used as a minimally invasive technique to restore lordosis. Safe execution requires a plane between the ALL and the anterior vasculature. An unfavorable plane on preoperative imaging is a contraindication to using the technique. We describe a patient undergoing multistage minimally invasive correction of a flat-back deformity who had an unfavorable plane between the ALL and vasculature at L4-5. Patient consent was provided, and Institutional Review Board approval was not required. To safely complete the ALL release and ACR, we elected to sharply incise the lateral aspect of the ligament at L4-5 with direct control of the vessels during the anterior approach for an L5-S1 anterior lumbar interbody fusion. We then moved to the lateral transpsoas approach and used controlled distraction techniques to complete the ALL release and then to complete the ACR in a standard fashion. We ultimately achieved excellent realignment with correction of the patient's flat-back deformity using minimally invasive surgical techniques while minimizing vascular risk. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

The use of deep brain stimulation (DBS) of the thalamus has been proven to be a safe and efficacious treatment for the management of many diseases. The most common indication for thalamic DBS remains essential tremor (ET), one of the most common movement disorders in the world. ET patients should be considered for surgical intervention when their tremor has demonstrated to be refractory to medication, a characteristic estimated to be present in roughly 50% of ET cases. Advantages of DBS over thalamotomy include its reversibility, the ability to adjust stimulation settings to optimize efficacy and minimize side effects, the ability to perform bilateral procedures safely, and an association with a lower risk of postoperative cognitive problems. The most common target of DBS for ET is the ventralis intermedius (VIM) of the thalamus, and the optimal electrode location corresponds to the anterior margin of the VIM. Other indications for thalamic DBS include non-ET tremor, obsessive-compulsive disorder, neuropathic pain, traumatic brain injury, Tourette's syndrome, and drug-resistant epilepsy among others.

Background Tethering after spinal surgery is caused by adhesions that arise from intradural tissue manipulation. Microsurgical detethering is the only treatment for symptomatic patients, but retethering occurs commonly and no treatment is widely available to prevent this complication. Objective To apply human amniotic membrane (HAM) grafts, which are immune-privileged and known to possess antifibrogenic properties, in patients requiring microsurgical detethering. For this first-in-human use, we evaluated the safety and potential efficacy of these grafts for preventing retethering. Methods We retrospectively reviewed the medical records of all patients who required detethering surgery and received an HAM graft between 2013 and 2016 at our institution after various previous intradural spinal surgeries. In all 14 cases, intradural lysis of adhesions was achieved, an HAM graft was sewn in place intradurally, and a dural patch was closed in a watertight fashion over the graft. Results Fourteen patients had received HAM grafts to prevent retethering. All patients had at least 6 mo of follow-up (mean follow-up, 14 mo). Retethering was noted in only 1 patient. Surgical re-exploration showed that the retethering occurred caudal to the edge of the HAM graft, with no tethering underneath the original graft. No complications were attributed specifically to the HAM graft placement. Conclusion This first-in-human series provides evidence that HAM grafts are a safe and potentially efficacious method for preventing retethering after microsurgical intradural lysis of adhesions. These results lay the groundwork for further prospective controlled trials in patients with this difficult-to-treat pathology.

Although the epilepsy refractory to medical therapy can potentially be cured by the resection of epileptogenic tissue, many patients do not qualify for surgery, because epileptogenic tissue can arise from eloquent areas of the brain, where surgical resection would result in severe neurological deficits. Palliative surgical treatments currently used in these situations include deep brain stimulation, responsive neurostimulation, and vagal nerve stimulation.1 A previously developed technique, multiple subpial transections (MSTs), although used infrequently, is another effective tool.2 Our patient, a 34-yr-old man, had epilepsy that was refractory to medical management. His preoperative work-up demonstrated a potential seizure focus in the left pars opercularis and left superior temporal gyrus, which was verified using invasive stereoelectroencephalography. Functional magnetic resonance imaging demonstrated a significant verbal and motor function in this region. After informed consent was obtained, the patient underwent a left-sided craniotomy. The central portion of the seizure focus was resected using the subpial technique. The surrounding presumed epileptogenic cortex, which was considered functionally eloquent, was then horizontally disconnected with MSTs. For each transection, a small puncture incision was made in the pia, and a vertical cut was completed using Morrell dissectors.2 MSTs were performed circumferentially around the entire resection cavity in 5-mm increments. All hemostasis was achieved with irrigation instead of electrocautery, although noncauterizing hemostatic agents are also acceptable. The patient was neurologically intact after the operation and was discharged home on postoperative day 2. He was free of seizures at 11-month follow-up. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

In contrast to traditional open spine procedures, minimally invasive spine (MIS) surgery reduces approach-related soft tissue disruption through retraction of local musculature and soft tissue. Aiding the development of MIS surgery have been the development of the intraoperative binocular microscope, muscular distraction systems such as tubular dilation, and percutaneous instrumentation, all of which have facilitated its application to a broad range of conditions (e.g., laminectomy, decompression, discectomy, interbody spacer placement, spinal deformity correction).