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Safety and comparative efficacy of initiating low-molecular-weight heparin within 24 hours of injury or surgery for venous thromboembolism prophylaxis in patients with spinal cord injury: a prospective TRACK-SCI registry study

Austin Lui, Christine Park, Timothy Chryssikos, Hannah Radabaugh, Arati Patel, Alexander A. Aabedi, Adam R. Ferguson, Abel Torres Espin, Praveen V. Mummaneni, Sanjay S. Dhall, Xuan Duong-Fernandez, Rajiv Saigal, Austin Chou, Jonathan Pan, Vineeta Singh, Debra D. Hemmerle, Nikos Kyritsis, Jason F. Talbott, Lisa U. Pascual, J. Russell Huie, William D. Whetstone, Jacqueline C. Bresnahan, Michael S. Beattie, Philip R. Weinstein, Geoffrey T. Manley, and Anthony M. DiGiorgio

OBJECTIVE

Venous thromboembolism (VTE) following traumatic spinal cord injury (SCI) is a significant clinical concern. This study sought to determine the incidence of VTE and hemorrhagic complications among patients with SCI who received low-molecular-weight heparin (LMWH) within 24 hours of injury or surgery and identify variables that predict VTE using the prospective Transforming Research and Clinical Knowledge in SCI (TRACK-SCI) database.

METHODS

The TRACK-SCI database was queried for individuals with traumatic SCI from 2015 to 2022. Primary outcomes of interest included rates of VTE (including deep vein thrombosis [DVT] and pulmonary embolism [PE]) and in-hospital hemorrhagic complications that occurred after LWMH administration. Secondary outcomes included intensive care unit and hospital length of stay, discharge location type, and in-hospital mortality.

RESULTS

The study cohort consisted of 162 patients with SCI. Fifteen of the 162 patients withdrew from the study, leading to loss of data for certain variables for these patients. One hundred thirty patients (87.8%) underwent decompression and/or fusion surgery for SCI. DVT occurred in 11 (7.4%) of 148 patients, PE in 9 (6.1%) of 148, and any VTE in 18 (12.2%) of 148 patients. The analysis showed that admission lower-extremity motor score (p = 0.0408), injury at the thoracic level (p = 0.0086), admission American Spinal Injury Association grade (p = 0.0070), and younger age (p = 0.0372) were significantly associated with VTE. There were 3 instances of postoperative spine surgery–related bleeding (2.4%) in the 127 patients who had spine surgery with bleeding complication data available, with one requiring return to surgery (0.8%). Thirteen (8.8%) of 147 patients had a bleeding complication not related to spine surgery. There were 2 gastrointestinal bleeds associated with nasogastric tube placement, 3 cases of postoperative non–spine-related surgery bleeding, and 8 cases of other bleeding complications (5.4%) not related to any surgery.

CONCLUSIONS

Initiation of LMWH within 24 hours was associated with a low rate of spine surgery–related bleeding. Bleeding complications unrelated to SCI surgery still occur with LMWH administration. Because neurosurgical intervention is typically the limiting factor in initializing chemical DVT prophylaxis, many of these bleeding complications would have likely occurred regardless of the protocol.

In Neurosurgical Focus Volume 55 (2023): Issue 4 (Oct 2023): Management and Controversies of Antithrombotic Medication in Neurosurgery

Open access

Paraparesis caused by intradural thoracic spinal granuloma secondary to organizing hematoma: illustrative case

John K. Yue, Young M. Lee, Daniel Quintana, Alexander A. Aabedi, Nishanth Krishnan, Thomas A. Wozny, John P. Andrews, and Michael C. Huang

BACKGROUND

Spinal granulomas form from infectious or noninfectious inflammatory processes and are rarely present intradurally. Intradural granulomas secondary to hematoma are unreported in the literature and present diagnostic and management challenges.

OBSERVATIONS

A 70-year-old man receiving aspirin presented with encephalopathy, subacute malaise, and right lower extremity weakness and was diagnosed with polysubstance withdrawal and refractory hypertension requiring extended treatment. Seven days after admission, he reported increased bilateral lower extremity (BLE) weakness. Magnetic resonance imaging showed T2–3 and T7–8 masses abutting the pia, with spinal cord compression at T2–3. He was transferred to the authors’ institution, and work-up showed no vascular shunting or malignancy. He underwent T2–3 laminectomies for biopsy/resection. A firm, xanthochromic mass was resected en bloc. Pathology showed organizing hematoma without infection, vascular malformation, or malignancy. Subsequent coagulopathy work-up was unremarkable. His BLE strength significantly improved, and he declined resection of the inferior mass. He completed physical therapy and was cleared for placement in a skilled nursing facility.

LESSONS

Spinal granulomas can mimic vascular lesions and malignancy. The authors present the first report of paraparesis caused by intradural granuloma secondary to organizing hematoma, preceded by severe refractory hypertension. Tissue diagnosis is critical, and resection is curative. These findings can inform the vigilant clinician for expeditious treatment.

In Journal of Neurosurgery: Case Lessons Volume 4 (2022): Issue 21 (Nov 2022)

Free access

Leveraging machine learning to ascertain the implications of preoperative body mass index on surgical outcomes for 282 patients with preoperative obesity and lumbar spondylolisthesis in the Quality Outcomes Database

Nitin Agarwal, Alexander A. Aabedi, Andrew K. Chan, Vijay Letchuman, Saman Shabani, Erica F. Bisson, Mohamad Bydon, Steven D. Glassman, Kevin T. Foley, Christopher I. Shaffrey, Eric A. Potts, Mark E. Shaffrey, Domagoj Coric, John J. Knightly, Paul Park, Michael Y. Wang, Kai-Ming Fu, Jonathan R. Slotkin, Anthony L. Asher, Michael S. Virk, Regis W. Haid Jr., Dean Chou, and Praveen V. Mummaneni

OBJECTIVE

Prior studies have revealed that a body mass index (BMI) ≥ 30 is associated with worse outcomes following surgical intervention in grade 1 lumbar spondylolisthesis. Using a machine learning approach, this study aimed to leverage the prospective Quality Outcomes Database (QOD) to identify a BMI threshold for patients undergoing surgical intervention for grade 1 lumbar spondylolisthesis and thus reliably identify optimal surgical candidates among obese patients.

METHODS

Patients with grade 1 lumbar spondylolisthesis and preoperative BMI ≥ 30 from the prospectively collected QOD lumbar spondylolisthesis module were included in this study. A 12-month composite outcome was generated by performing principal components analysis and k-means clustering on four validated measures of surgical outcomes in patients with spondylolisthesis. Random forests were generated to determine the most important preoperative patient characteristics in predicting the composite outcome. Recursive partitioning was used to extract a BMI threshold associated with optimal outcomes.

RESULTS

The average BMI was 35.7, with 282 (46.4%) of the 608 patients from the QOD data set having a BMI ≥ 30. Principal components analysis revealed that the first principal component accounted for 99.2% of the variance in the four outcome measures. Two clusters were identified corresponding to patients with suboptimal outcomes (severe back pain, increased disability, impaired quality of life, and low satisfaction) and to those with optimal outcomes. Recursive partitioning established a BMI threshold of 37.5 after pruning via cross-validation.

CONCLUSIONS

In this multicenter study, the authors found that a BMI ≤ 37.5 was associated with improved patient outcomes following surgical intervention. These findings may help augment predictive analytics to deliver precision medicine and improve prehabilitation strategies.

In Journal of Neurosurgery: Spine Volume 38: Issue 2 (Feb 2023)

Free access

Decision tree–based machine learning analysis of intraoperative vasopressor use to optimize neurological improvement in acute spinal cord injury

Nitin Agarwal, Alexander A. Aabedi, Abel Torres-Espin, Austin Chou, Thomas A. Wozny, Praveen V. Mummaneni, John F. Burke, Adam R. Ferguson, Nikos Kyritsis, Sanjay S. Dhall, Philip R. Weinstein, Xuan Duong-Fernandez, Jonathan Pan, Vineeta Singh, Debra D. Hemmerle, Jason F. Talbott, William D. Whetstone, Jacqueline C. Bresnahan, Geoffrey T. Manley, Michael S. Beattie, and Anthony M. DiGiorgio

OBJECTIVE

Previous work has shown that maintaining mean arterial pressures (MAPs) between 76 and 104 mm Hg intraoperatively is associated with improved neurological function at discharge in patients with acute spinal cord injury (SCI). However, whether temporary fluctuations in MAPs outside of this range can be tolerated without impairment of recovery is unknown. This retrospective study builds on previous work by implementing machine learning to derive clinically actionable thresholds for intraoperative MAP management guided by neurological outcomes.

METHODS

Seventy-four surgically treated patients were retrospectively analyzed as part of a longitudinal study assessing outcomes following SCI. Each patient underwent intraoperative hemodynamic monitoring with recordings at 5-minute intervals for a cumulative 28,594 minutes, resulting in 5718 unique data points for each parameter. The type of vasopressor used, dose, drug-related complications, average intraoperative MAP, and time spent in an extreme MAP range (< 76 mm Hg or > 104 mm Hg) were collected. Outcomes were evaluated by measuring the change in American Spinal Injury Association Impairment Scale (AIS) grade over the course of acute hospitalization. Features most predictive of an improvement in AIS grade were determined statistically by generating random forests with 10,000 iterations. Recursive partitioning was used to establish clinically intuitive thresholds for the top features.

RESULTS

At discharge, a significant improvement in AIS grade was noted by an average of 0.71 levels (p = 0.002). The hemodynamic parameters most important in predicting improvement were the amount of time intraoperative MAPs were in extreme ranges and the average intraoperative MAP. Patients with average intraoperative MAPs between 80 and 96 mm Hg throughout surgery had improved AIS grades at discharge. All patients with average intraoperative MAP > 96.3 mm Hg had no improvement. A threshold of 93 minutes spent in an extreme MAP range was identified after which the chance of neurological improvement significantly declined. Finally, the use of dopamine as compared to norepinephrine was associated with higher rates of significant cardiovascular complications (50% vs 25%, p < 0.001).

CONCLUSIONS

An average intraoperative MAP value between 80 and 96 mm Hg was associated with improved outcome, corroborating previous results and supporting the clinical verifiability of the model. Additionally, an accumulated time of 93 minutes or longer outside of the MAP range of 76–104 mm Hg is associated with worse neurological function at discharge among patients undergoing emergency surgical intervention for acute SCI.

In Neurosurgical Focus Volume 52 (2022): Issue 4 (Apr 2022): Big Data and New Technologies in Neurosurgical Decision-Making

Free access

Resection of supplementary motor area gliomas: revisiting supplementary motor syndrome and the role of the frontal aslant tract

Jacob S. Young, Andrew J. Gogos, Alexander A. Aabedi, Ramin A. Morshed, Matheus P. Pereira, Samuel Lashof-Regas, Ziba Mansoori, Tracy Luks, Shawn L. Hervey-Jumper, Javier E. Villanueva-Meyer, and Mitchel S. Berger

OBJECTIVE

The supplementary motor area (SMA) is an eloquent region that is frequently a site for glioma, or the region is included in the resection trajectory to deeper lesions. Although the clinical relevance of SMA syndrome has been well described, it is still difficult to predict who will become symptomatic. The object of this study was to define which patients with SMA gliomas would go on to develop a postoperative SMA syndrome.

METHODS

The University of California, San Francisco, tumor registry was searched for patients who, between 2010 and 2019, had undergone resection for newly diagnosed supratentorial diffuse glioma (WHO grades II–IV) performed by the senior author and who had at least 3 months of follow-up. Pre- and postoperative MRI studies were reviewed to confirm the tumor was located in the SMA region, and the extent of SMA resection was determined by volumetric assessment. Patient, tumor, and outcome data were collected retrospectively from documents available in the electronic medical record. Tumors were registered to a standard brain atlas to create a frequency heatmap of tumor volumes and resection cavities.

RESULTS

During the study period, 56 patients (64.3% male, 35.7% female) underwent resection of a newly diagnosed glioma in the SMA region. Postoperatively, 60.7% developed an SMA syndrome. Although the volume of tumor within the SMA region did not correlate with the development of SMA syndrome, patients with the syndrome had larger resection cavities in the SMA region (25.4% vs 14.2% SMA resection, p = 0.039). The size of the resection cavity in the SMA region did not correlate with the severity of the SMA syndrome. Patients who developed the syndrome had cavities that were located more posteriorly in the SMA region and in the cingulate gyrus. When the frontal aslant tract (FAT) was preserved, 50% of patients developed the SMA syndrome postoperatively, whereas 100% of the patients with disruption of the FAT during surgery developed the SMA syndrome (p = 0.06). Patients with SMA syndrome had longer lengths of stay (5.6 vs 4.1 days, p = 0.027) and were more likely to be discharged to a rehabilitation facility (41.9% vs 0%, p < 0.001). There was no difference in overall survival for newly diagnosed glioblastoma patients with SMA syndrome compared to those without SMA syndrome (1.6 vs 3.0 years, p = 0.33).

CONCLUSIONS

For patients with SMA glioma, more extensive resections and resections involving the posterior SMA region and posterior cingulate gyrus increased the likelihood of a postoperative SMA syndrome. Although SMA syndrome occurred in all cases in which the FAT was resected, FAT preservation does not reliably avoid SMA syndrome postoperatively.

In Journal of Neurosurgery Volume 136: Issue 5 (May 2022)

Free access

Balancing task sensitivity with reliability for multimodal language assessments

Alexander A. Aabedi, Sofia Kakaizada, Jacob S. Young, EunSeon Ahn, Daniel H. Weissman, Mitchel S. Berger, David Brang, and Shawn L. Hervey-Jumper

OBJECTIVE

Intraoperative tasks for awake language mapping are typically selected based on the language tracts that will likely be encountered during tumor resection. However, diminished attention and arousal secondary to perioperative sedatives may reduce a task’s usefulness for identifying eloquent cortex. For instance, accuracy in performing select language tasks may be high preoperatively but decline in the operating room. In the present study, the authors sought to identify language tasks that can be performed with high accuracy in both situational contexts so the neurosurgical team can be confident that speech errors committed during awake language mapping result from direct cortical stimulation to eloquent cortex, rather than from poor performance in general.

METHODS

We administered five language tasks to 44 patients: picture naming (PN), text reading (TR), auditory object naming (AN), repetition of 4-syllable words (4SYL), and production of syntactically intact sentences (SYNTAX). Performance was assessed using the 4-point scale of the quick aphasia battery 24 hours preoperatively and intraoperatively. We next determined whether or not accuracy on each task was higher preoperatively than intraoperatively. We also determined whether 1) intraoperative accuracy on a given task predicted intraoperative performance on the other tasks and 2) low preoperative accuracy on a task predicted a decrease in accuracy intraoperatively.

RESULTS

Relative to preoperative accuracy, intraoperative accuracy declined on PN (3.90 vs 3.82, p = 0.0001), 4SYL (3.96 vs 3.91, p = 0.0006), and SYNTAX (3.85 vs 3.67, p = 0.0001) but not on TR (3.96 vs 3.94, p = 0.13) or AN (3.70 vs 3.58, p = 0.058). Intraoperative accuracy on PN and AN independently predicted intraoperative accuracy on the remaining language tasks (p < 0.001 and p < 0.01, respectively). Finally, low preoperative accuracy on SYNTAX predicted a decrease in accuracy on this task intraoperatively (R = 0.36, p = 0.00002).

CONCLUSIONS

While TR lacks sensitivity in identifying language deficits at baseline, accuracy on TR is stable across testing settings. Baseline accuracy on the other four of our five language tasks was not predictive of intraoperative performance, signifying the need to repeat language tests prior to stimulation mapping to confirm reliability.

In Journal of Neurosurgery Volume 135: Issue 6 (Dec 2021)

Restricted access

Assessment of wakefulness during awake craniotomy to predict intraoperative language performance

Alexander A. Aabedi, EunSeon Ahn, Sofia Kakaizada, Claudia Valdivia, Jacob S. Young, Heather Hervey-Jumper, Eric Zhang, Oren Sagher, Daniel H. Weissman, David Brang, and Shawn L. Hervey-Jumper

OBJECTIVE

Maximal safe tumor resection in language areas of the brain relies on a patient’s ability to perform intraoperative language tasks. Assessing the performance of these tasks during awake craniotomies allows the neurosurgeon to identify and preserve brain regions that are critical for language processing. However, receiving sedation and analgesia just prior to experiencing an awake craniotomy may reduce a patient’s wakefulness, leading to transient language and/or cognitive impairments that do not completely subside before language testing begins. At present, the degree to which wakefulness influences intraoperative language task performance is unclear. Therefore, the authors sought to determine whether any of 5 brief measures of wakefulness predicts such performance during awake craniotomies for glioma resection.

METHODS

The authors recruited 21 patients with dominant hemisphere low- and high-grade gliomas. Each patient performed baseline wakefulness measures in addition to picture-naming and text-reading language tasks 24 hours before undergoing an awake craniotomy. The patients performed these same tasks again in the operating room following the cessation of anesthesia medications. The authors then conducted statistical analyses to investigate potential relationships between wakefulness measures and language task performance.

RESULTS

Relative to baseline, performance on 3 of the 4 objective wakefulness measures (rapid counting, button pressing, and vigilance) declined in the operating room. Moreover, these declines appeared in the complete absence of self-reported changes in arousal. Performance on language tasks similarly declined in the intraoperative setting, with patients experiencing greater declines in picture naming than in text reading. Finally, performance declines on rapid counting and vigilance wakefulness tasks predicted performance declines on the picture-naming task.

CONCLUSIONS

Current subjective methods for assessing wakefulness during awake craniotomies may be insufficient. The administration of objective measures of wakefulness just prior to language task administration may help to ensure that patients are ready for testing. It may also allow neurosurgeons to identify patients who are at risk for poor intraoperative performance.

In Journal of Neurosurgery Volume 132: Issue 6 (Jun 2020)