Hematologic and Inflammatory Predictors of Outcome in Patients with Brain Arteriovenous Malformations.

OBJECTIVE: This study investigated the prognostic value of admission blood counts for arteriovenous malformation (AVM) outcomes and compared admission blood counts for patients with ruptured and unruptured AVMs. METHODS: A retrospective analysis of patients who underwent surgical treatment for a ruptured cerebral AVM between February 1, 2014, and March 31, 2020, was conducted. The primary outcome was poor neurologic outcome, defined as a modified Rankin Scale score ≥2 in patients with unruptured AVMs or >2 in patients with ruptured AVMs. RESULTS: Of 235 included patients, 80 (34%) had ruptured AVMs. At admission, patients with ruptured AVMs had a significantly lower mean (SD) hemoglobin level (12.78 [2.07] g/dL vs. 13.71 [1.60] g/dL, P < 0.001), hematocrit (38.1% [5.9%] vs. 40.7% [4.6%], P < 0.001), lymphocyte count (16% [11%] vs. 26% [10%], P < 0.001), and absolute lymphocyte count (1.41 [0.72] × 103/µL vs. 1.79 [0.68] × 103/µL, P < 0.001), and they had a significantly higher mean (SD) white blood cell count (10.4 [3.8] × 103/µL vs. 7.6 [2.3] × 103/µL, P < 0.001), absolute neutrophil count (7.8 [3.8] × 103/µL vs. 5.0 [2.5] × 103/µL, P < 0.001), and neutrophil count (74% [14%] vs. 64% [13%], P < 0.001). Among patients with unruptured AVMs, white blood cell count ≥6.4 × 103/µL and absolute neutrophil count ≥3.4 × 103/µL were associated with a favorable neurologic outcome, whereas hemoglobin level ≥13.4 g/dL was associated with an unfavorable outcome. Among patients with ruptured AVMs, hypertension was associated with a 3-fold increase in odds of a poor neurologic outcome. CONCLUSIONS: Patients with ruptured and unruptured AVMs present with characteristic profiles of hematologic and inflammatory parameters evident in their admission blood work.

Early Treatment of Ruptured Cerebral Arteriovenous Malformations: Analysis of Neurological Outcomes and Health Care Costs.

BACKGROUND: The timing of surgical resection is controversial when managing ruptured arteriovenous malformations (AVMs) and varies considerably among centers. OBJECTIVE: To retrospectively analyze clinical outcomes and hospital costs associated with delayed treatment in a ruptured cerebral AVM patient cohort. METHODS: Patients undergoing surgical treatment for a ruptured cerebral AVM (January 1, 2015-December 31, 2020) were retrospectively analyzed. Patients who underwent emergent treatment of a ruptured AVM because of acute herniation were excluded, as were those treated >180 days after rupture. Patients were stratified by the timing of surgical intervention relative to AVM rupture into early (postbleed days 1-20) and delayed (postbleed days 21-180) treatment cohorts. RESULTS: Eighty-seven patients were identified. The early treatment cohort comprised 75 (86%) patients. The mean (SD) length of time between AVM rupture and surgical resection was 5 (5) days in the early cohort and 73 (60) days in the delayed cohort ( P < .001). The cohorts did not differ with respect to patient demographics, AVM size, Spetzler-Martin grade, frequency of preoperative embolization, or severity of clinical presentation ( P ≥ .15). Follow-up neurological status was equivalent between the cohorts ( P = .65). The associated mean health care costs were higher in the delayed treatment cohort ($241 597 [$99 363]) than in the early treatment cohort ($133 989 [$110 947]) ( P = .02). After adjustment for length of stay, each day of delayed treatment increased cost by a mean of $2465 (95% CI = $967-$3964, P = .002). CONCLUSION: Early treatment of ruptured AVMs was associated with significantly lower health care costs than delayed treatment, but surgical and neurological outcomes were equivalent.

Pseudarthrosis after four-level anterior cervical discectomy and fusion without posterior fixation.

OBJECTIVE: Fusion rates and long-term outcomes are well established for anterior cervical discectomy and fusion (ACDF) of 3 levels or fewer, but there is a paucity of similar data on 4-level fusions. The authors evaluated long-term fusion rates and clinical outcomes after 4-level ACDF without supplemental posterior instrumentation. METHODS: The authors retrospectively reviewed patients who underwent 4-level ACDF at a single institution with at least 1-year of radiological follow-up. Fusion was determined by measuring change in interspinous distance at each segment on dynamic radiographs or by the presence of bridging bone on CT scans at minimum 1-year follow-up. Clinical outcomes were assessed using Neck Disability Index and Short Form-36. RESULTS: A total of 63 patients (252 levels) met the inclusion criteria for the study, with a mean follow-up of 2.6 years. Complete radiographic fusion at all 4 levels was observed in 26 patients (41.3%). Of the 37 patients (58.7%) with radiographic pseudarthrosis, there was a mean of 1.35 nonfused levels. The fusion rate per level, however, was 80.2% (202/252 levels). The most common level demonstrating nonunion was the distal segment (C6-7), showing pseudarthrosis in 29 patients (46.8%), followed by the most proximal segment (C3-4) demonstrating nonunion in 9 patients (14.5%). The mean improvement in Neck Disability Index and Short Form-36 was 15.7 (p < 0.01) and 5.8 (p = 0.14), respectively, with improvement in both scores surpassing the minimum clinically important difference. One patient (1.6%) required revision surgery for symptomatic pseudarthrosis, and 5 patients (7.9%) underwent revision for symptomatic adjacent-segment disease. Patient-reported outcomes results are limited by the low rate of 1-year follow-up (50.8%), whereas reoperation data were available for all 63 patients. CONCLUSIONS: More than half of patients undergoing 4-level ACDF without posterior fixation demonstrated pseudarthrosis of at least 1 level-most commonly the distal C6-7 level. One patient required revision for symptomatic pseudarthrosis. Patient-reported outcomes showed significant improvements at 1-year follow-up, but clinical follow-up was limited. This is the largest series to date to evaluate fusion outcomes in 4-level ACDF.

Direct puncture of the superior ophthalmic vein for carotid cavernous fistulas: a 21-year experience.

BACKGROUND: Direct puncture of the superior ophthalmic vein (SOV) is an alternative approach to traversing the inferior petrosal sinus for embolization of carotid cavernous fistulas (CCFs). OBJECTIVE: To analyze direct SOV puncture for the treatment of CCFs and review the literature. METHODS: All patients at a single center, treated for a CCF with direct SOV cannulation between January 1, 2000, and December 31, 2020, were retrospectively analyzed. An additional review of the literature for all case series for direct puncture of the SOV for treatment of CCF was performed. RESULTS: During the 21-year study period, direct cannulation of the SOV for treatment of a CCF was attempted for 19 patients, with the procedure aborted for one patient because of an inability to navigate the wire into the distal aspect of the cavernous sinus. In 18 patients with direct SOV CCF treatment, 1 experienced a minor complication with an asymptomatic postoperative hemorrhage. Angiographic cure and improvement of symptoms were achieved in 17 patients with a mean (SD) follow-up of 6 (5.2) months. In the review of the literature, an additional 45 patients were reported to have direct cannulation of the SOV for CCF treatment, with angiographic cure in 43 (96%) and decreased objective visual acuity in 1 (2%). CONCLUSION: Direct SOV cannulation to treat CCFs is safe and effective. Although it is typically used after other endovascular approaches have failed, SOV access for CCF treatment may be warranted as a first-line treatment for select patients.

Pyoderma Gangrenosum Masquerading as Wound Infection in the Early Postoperative Period After Lumbar Spine Deformity Correction Surgery.

The development of pyoderma gangrenosum (PG) after surgical site trauma is a rare, poorly understood immunologic phenomenon. PG is an immunologic disorder characterized by lymphocytic infiltration of the dermis that can manifest with skin necrosis and ulceration. This rare phenomenon can mimic surgical site infection (SSI) when it occurs in the perioperative period and in the region of surgical wounds. Within the neurosurgical literature, only two cases of postoperative PG have been reported to our knowledge. We describe the clinical features and treatment of PG in the case of a 65-year-old man who underwent a three-stage surgical approach for intractable mechanical low back pain on hospital days (HDs) 1 and 2, and who subsequently developed PG around all three surgical sites in the immediate postoperative period (HD 8). The physical and laboratory findings and surgical and pharmacologic treatments are detailed. The patient was initially treated for presumed SSI, started on broad-spectrum antibiotics, and underwent surgical wound debridement twice, without resolution of symptoms. The diagnosis of PG was ultimately made by a consulting dermatologist on HD 17. The patient was started on systemic immunosuppression with steroids during his initial hospitalization; symptoms resolved within two weeks of the index surgery. Although PG is a rare entity, we suggest that it be considered in the differential diagnosis of nonhealing surgical wounds. Familiarity with PG may help mitigate unnecessary surgical morbidity and reduce the length of hospital stays and unnecessary use of antibiotics.

Emerging pathogenic mechanisms in human brain arteriovenous malformations: a contemporary review in the multiomics era.

A variety of pathogenic mechanisms have been described in the formation, maturation, and rupture of brain arteriovenous malformations (bAVMs). While the understanding of bAVMs has largely been formulated based on animal models of rare hereditary diseases in which AVMs form, a new era of "omics" has permitted large-scale examinations of contributory genetic variations in human sporadic bAVMs. New findings regarding the pathogenesis of bAVMs implicate changes to endothelial and mural cells that result in increased angiogenesis, proinflammatory recruitment, and breakdown of vascular barrier properties that may result in hemorrhage; a greater diversity of cell populations that compose the bAVM microenvironment may also be implicated and complicate traditional models. Genomic sequencing of human bAVMs has uncovered inherited, de novo, and somatic activating mutations, such as KRAS, which contribute to the pathogenesis of bAVMs. New droplet-based, single-cell sequencing technologies have generated atlases of cell-specific molecular derangements. Herein, the authors review emerging genomic and transcriptomic findings underlying pathologic cell transformations in bAVMs derived from human tissues. The application of multiple sequencing modalities to bAVM tissues is a natural next step for researchers, although the potential therapeutic benefits or clinical applications remain unknown.

Increasing author counts in neurosurgical journals from 1980 to 2020.

OBJECTIVE: Scientific productivity, as assessed by publication volume, is a common metric by which the academic neurosurgical field assesses its members. The number of authors per peer-reviewed article has been observed to increase over time across a broad range of medical specialties. This study provides an update to this trend in the neurosurgical literature. METHODS: All publications from January 1, 1980, to April 30, 2020, were queried from four neurosurgical journals: Neurosurgery, Journal of Neurosurgery (JNS), JNS: Pediatrics, and JNS: Spine. Publication information was acquired from the National Center for Biotechnology Information Entrez database and reconciled with the Scopus database. Publication type was limited to articles and excluded editorials, letters, and reviews. The number of authors and affiliation counts were determined based on structured abstract fields provided in the two databases. RESULTS: Between January 1, 1980, and April 30, 2020, the overall increase in author count for the four neurosurgical journals was 0.12 to 0.18 authors per year (p < 0.001). For Neurosurgery, the mean (SD) author count increased from 2.81 (1.4) in 1980-1985 to 7.97 (4.92) in 2016-2020 (p < 0.001). For the JNS, the mean (SD) author count increased from 2.82 (1.04) in 1980-1985 to 7.6 (3.65) in 2016-2020 (p < 0.001). The percentage of articles with more than 10 authors increased from 0.2% to 22.3% in Neurosurgery and from 1.9% to 17.5% in JNS. Only 28% of the author count variation was explained by an increasing number of institutional or departmental affiliations. CONCLUSIONS: Author counts for peer-reviewed articles in neurosurgical academic journals have increased significantly during the past 4 decades, with large increases in the numbers of articles with more than 10 authors in the past 5 years. A total of 28% of the variation in this increase can be explained by an increase in multiinstitutional or multidepartmental studies.

Emerging Technologies in Spinal Surgery: Ultra-Low Radiation Imaging Platforms.

BACKGROUND: Spine surgery has seen tremendous growth in the past 2 decades. A variety of safety, practical, and market-driven needs have spurred the development of new imaging technologies as necessary tools for modern-day spine surgery. Although current imaging techniques have proven satisfactory for operative needs, it is well-known that these techniques have negative consequences for operators and patients in terms of radiation risk. Several mitigating techniques have arisen in recent years, ranging from lead protection to radiation-reducing protocols, although each technique has limits. A hitherto-problematic barrier has been the fact that efforts to diminish radiation emission come at the cost of reduced image quality. OBJECTIVE: To describe new ultra-low radiation imaging modalities that have the potential to drastically reduce radiation risk and minimize unacceptable adverse effects. METHODS: A literature review was performed of articles and studies that used either of 2 ultra-low radiation imaging modalities, the EOS system (EOS-Imaging S.A., Paris, France) and LessRay (NuVasive, San Diego, CA). RESULTS: Both ultra-low radiation imaging modalities reduce radiation exposure in the preoperative and perioperative settings. EOS provides 3-dimensional reconstructive capability, and LessRay offers intraoperative tools that facilitate spinal localization and proper visual alignment of the spine. CONCLUSION: These novel radiation-reducing technologies diminish patient and surgeon exposure, aid the surgeon in preoperative planning, and streamline intraoperative workflow.

Perioperative and swallowing outcomes in patients undergoing 4- and 5-level anterior cervical discectomy and fusion.

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is a common and robust procedure performed on the cervical spine. Literature on ACDF for 4 or more segments is sparse. Increasing the number of operative levels increases surgical complexity, tissue retraction, and risks of complications, particularly dysphagia. The overall risks of these complications and rates of dysphagia are not well studied for surgery on 4 or more segments. In this study, the authors evaluated their institution's perioperative experience with 4- and 5-level ACDFs. METHODS: The authors retrospectively reviewed patients who underwent 4- or 5-level ACDF at their institution over a 6-year period (May 2013-May 2019). Patient demographics, perioperative complications, readmission rates, and swallowing outcomes were recorded. Outcomes were analyzed with a multivariate linear regression. RESULTS: A total of 174 patients were included (167 had 4-level and 7 had 5-level ACDFs). The average age was 60.6 years, and 54.0% of patients (n = 94) were men. A corpectomy was performed in 12.6% of patients (n = 22). After surgery, 56.9% of patients (n = 99) experienced dysphagia. The percentage of patients with dysphagia decreased to 22.8% (37/162) at 30 days, 12.9% (17/132) at 90 days, and 6.3% (5/79) and 2.8% (1/36) at 1 and 2 years, respectively. Dysphagia was more likely at 90 days postoperatively in patients with gastroesophageal reflux (OR 4.4 [95% CI 1.5-12.8], p = 0.008), and the mean (± SD) lordosis change was greater in patients with dysphagia than those without at 90 days (19.8° ± 13.3° vs 9.1° ± 10.2°, p = 0.003). Dysphagia occurrence did not differ with operative implants, including graft and interbody type. The mean length of time to solid food intake was 2.4 ± 2.1 days. Patients treated with dexamethasone were more likely to achieve solid food intake prior to discharge (OR 4.0 [95% CI 1.5-10.6], p = 0.004). Postsurgery, 5.2% of patients (n = 9) required a feeding tube due to severe approach-related dysphagia. Other perioperative complication rates were uniformly low. Overall, 8.6% of patients (n = 15) returned to the emergency department within 30 days and 2.9% (n = 5) required readmission, whereas 1.1% (n = 2) required unplanned return to surgery within 30 days. CONCLUSIONS: This is the largest series of patients undergoing 4- and 5-level ACDFs reported to date. This procedure was performed safely with minimal intraoperative complications. More than half of the patients experienced in-hospital dysphagia, which increased their overall length of stay, but dysphagia decreased over time.

Robotics in Spine Surgery: A Technical Overview and Review of Key Concepts.

The use of robotic systems to aid in surgical procedures has greatly increased over the past decade. Fields such as general surgery, urology, and gynecology have widely adopted robotic surgery as part of everyday practice. The use of robotic systems in the field of spine surgery has recently begun to be explored. Surgical procedures involving the spine often require fixation via pedicle screw placement, which is a task that may be augmented by the use of robotic technology. There is little margin for error with pedicle screw placement, because screw malposition may lead to serious complications, such as neurologic or vascular injury. Robotic systems must provide a degree of accuracy comparable to that of already-established methods of screw placement, including free-hand, fluoroscopically assisted, and computed tomography-assisted screw placement. In the past several years, reports have cataloged early results that show the robotic systems are associated with equivalent accuracy and decreased radiation exposure compared with other methods of screw placement. However, the literature is still lacking with regard to long-term outcomes with these systems. This report provides a technical overview of robotics in spine surgery based on experience at a single institution using the ExcelsiusGPS (Globus Medical; Audobon, PA, USA) robotic system for pedicle screw fixation. The current state of the field with regard to salient issues in robotics and future directions for robotics in spinal surgery are also discussed.

Hemiepiphyseodesis for Juvenile and Adolescent Tibia Vara Utilizing Percutaneous Transphyseal Screws.

BACKGROUND: In juvenile and adolescent tibia vara patients with sufficient growth remaining, implant-controlled hemiepiphyseodesis, or guided growth, can be used to correct deformity. Recent reports have described hardware failure of certain hemiepiphyseodesis implants in overweight patients with tibia vara. We describe our experience using transphyseal screws to correct deformity in this patient population. METHODS: A retrospective chart and radiograph review was conducted on all juvenile and adolescent tibia vara patients who underwent lateral proximal tibial hemiepiphyseodesis using a single transphyseal screw. Charts were queried for preoperative and postoperative mechanical axis deviation, medial proximal tibial angle, lateral distal femoral angle, and postoperative complications or need for further surgery. RESULTS: In total, 14 affected limbs in 9 patients (6 males) who underwent lateral proximal tibial transphyseal screw hemiepiphyseodesis were considered. Average chronologic age at implantation was 10.4 years and average body mass index was 31.7 kg/m. At average 23-month follow-up, the average mechanical axis deviation improved from 46 to 0 mm (P<0.001), and the average medial proximal tibial angle improved from 81 to 92 degrees (P<0.001). No limbs underwent further surgery to correct residual deformity. There were no complications or instances of implant failure associated with the transphyseal screws. CONCLUSIONS: Hemiepiphyseodesis using transphyseal screws is an effective technique to correct deformity in juvenile and adolescent tibia vara patients with sufficient growth remaining. This method can be used safely with few complications and with minimal risk of mechanical failure, even in overweight patients. LEVEL OF EVIDENCE: Level IV-therapeutic.

Single position spinal surgery for the treatment of grade II spondylolisthesis: A technical note.

BACKGROUND AND IMPORTANCE: Minimally invasive transpsoas approach to treat lumbar spondylolisthesis is associated with increased clinical benefits. CLINICAL PRESENTATION: Robotic and navigation aided deformity correction for grade II spondylolisthesis was performed using transpsoas approach with pedicle screw placement in lateral decubitus position. CONCLUSION: Keeping the patient in the lateral decubitus position, we supplemented interbody cage placement with screws. Single position lateral transpsoas approach provides grade II spondylolisthesis improvement.

Experience with definitive instrumented final fusion after posterior-based distraction lengthening in patients with early-onset spinal deformity: single center results.

Limited reports exist with regard to clinical and radiographic details of patients with early-onset spinal deformity (EOSD) undergoing definitive instrumented final fusion (FF) following implantation of a growing construct. Charts and radiographs were queried for all patients who underwent FF after management of EOSD with a distraction-based posterior construct at a single institution from 2006 to 2017. Patients managed during the growth modulation period with either proximal rib or spinal fixation were included. Thirteen patients qualified for inclusion. Spinal deformity etiologies were varied (neuromuscular: 5, idiopathic: 4, congenital: 4). Average age at implantation was 6.5 years, and patients underwent an average of 8.15 lengthening procedures over an average of 69 months. After the growing program, modest correction in main coronal Cobb was obtained at FF (average 52.4° before FF, 37.6° following FF, P<0.001; average percent improvement of 27%). Five patients required posterior column osteotomies. Using criteria proposed by Flynn and colleagues, 'minimal' coronal correction was achieved in 23% of patients and 'moderate' in 77%. No patient achieved 'substantial' (>50%) correction. Subjective poor bone quality was appreciated in 67% of patients, and 85% were noted to have areas of autofusion over previously spanned levels. Two (15%) patients sustained a total of four complications. After growth modulation procedures, EOSD deformities are generally stiff, bone quality is often subjectively poor, and autofusion is common, even after use of proximally rib-based systems. Modestly improved coronal Cobb correction can be obtained at FF but may require single or multiple posterior osteotomies. Intraoperative difficulties can be expected, and clinicians should be alert for intraoperative and postoperative complications.

Sciatica Caused by Venous Varix Compression of the Sciatic Nerve.

BACKGROUND: The authors report the case of a 76-year-old woman presenting with leg pain, numbness, and weakness mimicking a lumbosacral radiculopathy. CASE DESCRIPTION: Initial lumbar spine magnetic resonance imaging demonstrated mild root compression, but lumbar decompression afforded only transient symptomatic relief. Postoperative magnetic resonance imaging of the lumbosacral plexus and sciatic nerve revealed a gluteal venous varix compressing the sciatic nerve just distal to the piriformis muscle. Neurolysis and surgical resection of the offending varix resulted in resolution of her symptoms. CONCLUSIONS: Variceal compression is a rare cause of extraspinal origin of lower extremity radicular pain. It should be considered if there is lack of correlation between radiologic findings and the clinical picture or if there is a failure of response to treatment of the assumed spinal cause.