Leiomyogenic Tumor of the Spine: A Systematic Review

The study cohort consisted of 83 patients with a mean age of 49.55 (SD 13.72) with a female preponderance (60 patients). Here, 32.14% of patients had primary LTS; the remaining were metastases. Clinical presentation included nonspecific back pain (57.83%), weakness (21.69%) and radicular pain (18.07%). History of uterine neoplasia was found in 33.73% of patients. LTS preferentially affected the thoracic spine (51.81%), followed by the lumbar (21.67%) spine. MRI alone was the most common imaging modality (33.33%); in other cases, it was used with CT (22.92%) or X-ray (16.67%); 19.23% of patients had Resection/Fixation, 15.38% had Total en bloc spondylectomy, and 10.26% had Corpectomy. A minority of patients had laminectomy and decompression. Among those with resection, 45.83% had a gross total resection, 29.17% had a subtotal resection, and 16.67% had a near total resection. Immunohistochemistry demonstrated positivity for actin (43.37%), desmin (31.33%), and Ki67 (25.30). At a follow-up of 19.3 months, 61.97% of patients were alive; 26.25% of 80 patients received no additional treatment, 23.75% received combination radiotherapy and chemotherapy, only chemotherapy was given to 20%, and radiotherapy was given to 17.5%. Few (2.5%) had further resection. For an average of 12.50 months, 42.31% had no symptoms, while others had residual (19.23%), other metastasis (15.38%), and pain (7.69%). On follow-up of 29 patients, most (68.97%) had resolved symptoms; 61.97% of the 71 patients followed were alive.

Outcomes Following Early Postoperative Adjuvant Radiosurgery for Brain Metastases

Importance

Adjuvant stereotactic radiosurgery (SRS) enhances the local control of resected brain metastases (BrM). However, the risks of local failure (LF) and potential for posttreatment adverse radiation effects (PTRE) after early postoperative adjuvant SRS have not yet been established.

Objective

To evaluate whether adjuvant SRS delivered within a median of 14 days after surgery is associated with improved LF without a concomitant increase in PTRE.

Design, Setting, and Participants

This prospective cohort study examines a clinical workflow (RapidRT) that was implemented from 2019 to 2022 to deliver SRS to surgical patients within a median of 14 days, ensuring all patients were treated within 30 days postoperatively. This prospective cohort was compared with a historical cohort (StanRT) of patients with BrM resected between 2013 and 2019 to assess the association of the RapidRT workflow with LF and PTRE. The 2 cohorts were combined to identify optimal SRS timing, with a median follow-up of 3.3 years for survivors.

Exposure

Timing of adjuvant SRS (14, 21, and 30 days postoperatively).

Main Outcomes and Measures

LF and PTRE, according to modified Response Assessment in Neuro-Oncology Brain Metastases criteria.

Results

There were 438 patients (265 [60.5%] female patients; 23 [5.3%] Asian, 27 [6.2%] Black, and 364 [83.1%] White patients) with a mean (SD) age of 62 (13) years; 377 were in the StanRT cohort and 61 in the RapidRT cohort. LF and PTRE rates at 1 year were not significantly different between RapidRT and StanRT cohorts. Timing of SRS was associated with radiographic PTRE. Patients receiving radiation within 14 days had the highest 1-year PTRE rate (18.08%; 95% CI, 8.31%-30.86%), and patients receiving radiation between 22 and 30 days had the lowest 1-year PTRE rate (4.10%; 95% CI, 1.52%-8.73%; P = .03). LF rates were highest for patients receiving radiation more than 30 days from surgery (10.65%; 95% CI, 6.90%-15.32%) but comparable for patients receiving radiation within 14 days, between 15 and 21 days, and between 22 and 30 days (≤14 days: 5.12%; 95% CI, 0.86%-15.60%; 15 to ≤21 days: 3.21%; 95% CI, 0.59%-9.99%; 22 to ≤30 days: 6.58%; 95% CI, 3.06%-11.94%; P = .20).

Conclusions and Relevance

In this cohort study of adjuvant SRS timing following surgical resection of BrM, the optimal timing for adjuvant SRS appears to be within 22 to 30 days following surgery. The findings of this study suggest that this timing allows for a balanced approach that minimizes the risks associated with LF and PTRE.

Development and Internal Validation of the Postoperative Analgesic Intake Needs Score: A Predictive Model for Post-Operative Narcotic Requirement after Spine Surgery

STUDY DESIGN

Retrospective Cohort.

OBJECTIVE

The aim of this study was to develop a clinical tool to pre-operatively risk-stratify patients undergoing spine surgery based on their likelihood to have high postoperative analgesic requirements.

METHODS

A total of 1199 consecutive patients undergoing elective spine surgery over a 2-year period at a single center were included. Patients not requiring inpatient admission, those who received epidural analgesia, those who had two surgeries at separate sites under one anesthesia event, and those with a length of stay greater than 10 days were excluded. The remaining 860 patients were divided into a derivation and validation cohort. Pre-operative factors were collected by review of the electronic medical record. Total postoperative inpatient opioid intake requirements were converted into morphine milligram equivalents to standardize postoperative analgesic requirements.

RESULTS

The postoperative analgesic intake needs (PAIN) score was developed after the following predictor variables were identified: age, race, history of depression/anxiety, smoking status, active pre-operative benzodiazepine use and pre-operative opioid use, and surgical type. Patients were risk-stratified based on their score with the high-risk group being more likely to have high opioid consumption postoperatively compared to the moderate and low-risk groups in both the derivation and validation cohorts.

CONCLUSION

The PAIN Score is a pre-operative clinical tool for patients undergoing spine surgery to risk stratify them based on their likelihood for high analgesic requirements. The information can be used to individualize a multi-modal analgesic regimen rather than utilizing a "one-size fits all" approach.

Orbital Exenteration for Craniofacial Lesions: A Systematic Review and Meta-Analysis of Patient Characteristics and Survival Outcomes

BACKGROUND

The outcomes of orbital exenteration (OE) in patients with craniofacial lesions (CFLs) remain unclear. The present review summarizes the available literature on the clinical outcomes of OE, including surgical outcomes and overall survival (OS).

METHODS

Relevant articles were retrieved from Medline, Scopus, and Cochrane according to PRISMA guidelines. A systematic review and meta-analysis were conducted on the clinical characteristics, management, and outcomes.

RESULTS

A total of 33 articles containing 957 patients who underwent OE for CFLs were included (weighted mean age: 64.3 years [95% CI: 59.9-68.7]; 58.3% were male). The most common lesion was squamous cell carcinoma (31.8%), and the most common symptom was disturbed vision/reduced visual acuity (22.5%). Of the patients, 302 (31.6%) had total OE, 248 (26.0%) had extended OE, and 87 (9.0%) had subtotal OE. Free flaps (33.3%), endosseous implants (22.8%), and split-thickness skin grafts (17.2%) were the most used reconstructive methods. Sino-orbital or sino-nasal fistula (22.6%), flap or graft failure (16.9%), and hyperostosis (13%) were the most reported complications. Regarding tumor recurrences, 38.6% were local, 32.3% were distant, and 6.7% were regional. The perineural invasion rate was 17.4%, while the lymphovascular invasion rate was 5.0%. Over a weighted mean follow-up period of 23.6 months (95% CI: 13.8-33.4), a weighted overall mortality rate of 39% (95% CI: 28-50%) was observed. The 5-year OS rate was 50% (median: 61 months [95% CI: 46-83]). The OS multivariable analysis did not show any significant findings.

CONCLUSIONS

Although OE is a disfiguring procedure with devastating outcomes, it is a viable option for carefully selected patients with advanced CFLs. A patient-tailored approach based on tumor pathology, extension, and overall patient condition is warranted.

Maintenance of pig brain function under extracorporeal pulsatile circulatory control (EPCC)

Selective vascular access to the brain is desirable in metabolic tracer, pharmacological and other studies aimed to characterize neural properties in isolation from somatic influences from chest, abdomen or limbs. However, current methods for artificial control of cerebral circulation can abolish pulsatility-dependent vascular signaling or neural network phenomena such as the electrocorticogram even while preserving individual neuronal activity. Thus, we set out to mechanically render cerebral hemodynamics fully regulable to replicate or modify native pig brain perfusion. To this end, blood flow to the head was surgically separated from the systemic circulation and full extracorporeal pulsatile circulatory control (EPCC) was delivered via a modified aorta or brachiocephalic artery. This control relied on a computerized algorithm that maintained, for several hours, blood pressure, flow and pulsatility at near-native values individually measured before EPCC. Continuous electrocorticography and brain depth electrode recordings were used to evaluate brain activity relative to the standard offered by awake human electrocorticography. Under EPCC, this activity remained unaltered or minimally perturbed compared to the native circulation state, as did cerebral oxygenation, pressure, temperature and microscopic structure. Thus, our approach enables the study of neural activity and its circulatory manipulation in independence of most of the rest of the organism.

Single Nucleotide Polymorphisms and Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-Analysis of the Literature

STUDY DESIGN

Meta-analysis.

OBJECTIVE

To determine the single nucleotide polymorphisms (SNPs) that are related to adult idiopathic scoliosis.

SUMMARY AND BACKGROUND DATA

Adolescent idiopathic scoliosis (AIS) is considered one of the most prevalent spinal diseases. Even though the cause of AIS is yet to be determined, family history and sex have shown conclusive associations. Multiple studies have indicated that AIS is more prevalent in families where at least one other first-degree relative is similarly affected, indicating a possible genetic etiology to AIS.

MATERIALS AND METHODS

Articles were collected from 3 different search engines and then processed in 2 stages for final article selection for quantitative analysis. Five different genetic models were represented to show the association between the different SNPs and AIS. The Hardy-Weinberg equilibrium was examined using Fisher exact test, with significance set at P <0.05. The final analysis paper's quality was evaluated using the Newcastle Ottawa Scale. Kappa interrater agreement was calculated to evaluate the agreement between authors.

RESULTS

The final analysis comprised 43 publications, 19412 cases, 22005 controls, and 25 distinct genes. LBX1 rs11190870 T>C and MATN-1 SNPs were associated with an increased risk of AIS in one or all of the 5 genetic models. IGF-1 , estrogen receptor alfa, and MTNR1B , SNPs were not associated with AIS in all 5 genetic models. Newcastle Ottawa Scale showed good quality for the selected articles. Cohen k = 0.741 and Kappa interrater agreement of 84% showed that the writers were in strong agreement.

CONCLUSIONS

There seem to be associations between AIS and genetic SNP. Further larger studies should be conducted to validate the results.

Refining the Anatomy of Percutaneous Trigeminal Rhizotomy: A Cadaveric, Radiological, and Surgical Study

BACKGROUND

Percutaneous trigeminal rhizotomy (PTR) is a widely used procedure for trigeminal neuralgia. However, comprehensive analyses that combine anatomic, radiological, and surgical considerations are rare.

OBJECTIVE

To present high-quality anatomic dissections and radiological studies that highlight the technical nuances of this procedure.

METHODS

Six silicon-injected postmortem heads underwent PTR. The surgical corridors were dissected, and the neurovascular relationships were studied. In addition, 20 dried human skulls and 50 computed tomography angiography and MRI scans were collected to study the anatomic relationships for a customized puncture corridor.

RESULTS

The PTR corridor was divided into 3 segments: the buccal segment (length, 34.76 ± 7.20 mm), the inferior temporal fossa segment (length, 42.06 ± 6.92 mm), and the Meckel cave segment (length, 24.75 ± 3.34 mm). The puncture sagittal (α) and axial (β) angles measured in this study were 38.32° ± 4.62° and 19.13° ± 2.82°, respectively. The precondylar reference line coincided with the foramen ovale in 75% of the computed tomography angiography scans, and the postcondylar line coincided with the carotid canal in 70% of the computed tomography angiography scans; these lines serve as the intraoperative landmarks for PTR. The ovale-carotid-pterygoid triangle, delineated by drawing a line from the foramen ovale to the carotid canal and the lateral pterygoid plate, is a distinguished landmark to use for avoiding neurovascular injury during fluoroscopy.

CONCLUSION

Knowledge of the anatomic and radiological features of PTR is essential for a successful surgery, and a customized technical flow is a safe and effective way to access the foramen ovale.

Postradiosurgery cystic degeneration in brain metastases causing delayed and potentially severe sequelae: systematic review and illustrative cases

BACKGROUND

Cystic postradiation degeneration has previously been described in the literature as a rare but potentially severe complication after central nervous system (CNS) irradiation for vascular malformations. Limited cases have been reported in the setting of brain metastases.

OBSERVATIONS

Thirty-six total cases, including three reported here, of cystic postradiation degeneration are identified. Of 35 cases with complete clinical information, 34 (97.25%) of 35 were symptomatic from cystic changes at diagnosis. The average time between initial radiation dose and cyst development was 7.61 years (range 2-31 years). Although most patients were initially treated conservatively with medication, including steroids, 32 (88.9%) of 36 ultimately required surgical intervention. The most common interventions were craniotomy for cyst fenestration or resection (25 of 36; 69.4%) and Ommaya placement (8 of 36). After intervention, clinical improvement was seen in 10 (67%) of 15 cases, with persistent or worsening deficit or death seen in 5 (33%) of 15. Cysts were decompressed or obliterated on postoperative imaging in 20 (83.3%) of 24 cases, and recurrence was seen in 4 (16.7%) of 24.

LESSONS

Cystic degeneration is a rare and delayed sequela after radiation for brain metastases. This entity has the potential to cause significant and permanent neurological deficit if not properly recognized and addressed. Durable control can be achieved with a variety of surgical treatments, including cyst fenestration and Ommaya placement.

Patient-Reported Outcomes in Endoscopic Endonasal Skull Base Surgery

The functional outcome, quality of life, and patient feedback related to a chosen treatment approach in skull base surgery have become a subject of interest and focused research in recent years. The current advances in endoscopic optical imaging technology and surgical precision have radically lowered the perioperative morbidity associated with skull base surgery. This has pushed toward a higher focus on patient-reported outcomes (PROs). It is now critical to ensure that the offered treatment plan and approach align with the patient's preferences and expectations, in addition to the surgeon's best clinical judgment and experience. PROs represent a view that reflects the patient's own thoughts and perspective on their condition and the management options, without input or interpretations from the surgeon. Having PRO data enables patients the opportunity to learn from the experiences and perspectives of other patients. This input empowers the patient to become an active participant in the decision-making process at different stages of their care. An in-depth PRO evaluation requires specific validated tools and scoring systems, namely the patient-reported outcomes measures (PROM) tools. In this review, we discuss the currently available skull-base-related PROs, the assessment tools used to capture them, and the future trends of this important topic that is in its infancy.

Tumors Involving the Infratemporal Fossa: A Systematic Review of Clinical Characteristics and Treatment Outcomes

BACKGROUND

Infratemporal fossa (ITF) tumors represent various pathologies and are seldom described in the literature, reflecting their rarity. Here we review the literature on tumors invading ITF and describe patient characteristics, treatment strategies, and clinical outcomes.

METHODS

Relevant articles were retrieved from PubMed, Scopus, and Cochrane. A systematic review and meta-analysis were conducted on the clinical presentation, treatment protocols, and clinical outcomes.

RESULT

A total of 27 articles containing 106 patients with ITF tumors (median tumor size: 24.3 cm³ [interquartile range, 15.2-42 cm³]) were included (median age: 46 years [interquartile range, 32-55 years]; 59.4% were males]). Of the confirmed tumor pathology data, schwannomas (n = 24; 26.1%) and meningiomas (n = 13; 14.1%) were the most common tumors. Facial hypoesthesia (n = 22; 18.5%), auricular/preauricular pain (n = 20; 16.8%), and headaches (n = 11; 9.2%) were the most common presenting symptoms. Of patients who had surgical resection (n = 97; 95.1%), 70 (73.7%) had transcranial surgery (TCS) and 25 (26.3%) had endoscopic endonasal surgery (EES). Among available details on the extent of resection (n = 84), gross-total resection (GTR) was achieved in 62 (73.8%), and 5 (6.0%) had biopsy only. Thirty-five (33.0%) patients had postoperative complications. Among cases with available data on reconstruction techniques (n = 8), four (50%) had adipofascial antero-lateral thigh flap, three (37.5%) had latissimus dorsi free flap, and one (12.5%) had antero-lateral thigh flap. Fourteen (13.2%) patients had adjuvant chemotherapy, and sixteen (15.1%) had adjuvant radiotherapy. During a median follow-up time of 28 months (IQR, 12.25-45.75 months), 15 (14.2%) patients had recurrences, and 18 (17.0%) patients died. The median overall survival (OS) time was 36 months (95% confidence interval: 29-41 months), and the 5-year progression-free survival (PFS) rate was 61%.

CONCLUSION

Various tumor types with different biological characteristics invade the ITF. The present study describes patient demographics, clinical presentation, management, and outcomes. Depending on the tumor type and patient condition, patient-tailored management is recommended to optimize treatment outcomes.

Integrated Multidisciplinary Brain Metastasis Care Reduces Patient Visits and Shortens Time to Adjuvant Irradiation

PURPOSE

Timely surgical cavity stereotactic radiosurgery (SRS) is an important adjuvant to brain metastasis resection, with earlier treatment associated with less frequent recurrence. The logistical complexity of treatment organization, however, has resulted in suboptimal start times postsurgically. We implemented a process improvement approach to reduce the time from surgery to adjuvant irradiation of resected brain metastases.

METHODS

A multidisciplinary working group used process mapping to identify opportunities to reduce visits and shorten treatment times. The care delivery process was modified to streamline perioperative SRS preparation with (1) early patient identification, (2) preoperative intrateam communication, and (3) consolidation of required steps. Plan-Do-Study-Act cycles were used for process improvement. The surgery-to-SRS initiation time interval was the primary outcome. Secondary outcomes included the number of associated patient encounters.

RESULTS

After implementation, the median (interquartile range) interval from surgery to SRS was reduced 48% from 27 (21-34) to 14 days (13-17; P < .001). The rate of surgical cavity SRS within 30 days increased from 64% (n = 63 of 98) to 97% (n = 60 of 62; P < .001). The median (interquartile range) number of CNS-associated encounters between resection and SRS decreased from 5 (4-6) to 4 (3-5; P < .001). The proportion of patients who had > 1 magnetic resonance imaging/computed tomography between surgery and SRS decreased from 45% (44 of 98) to 13% (8 of 62; P < .001). The time from surgery to systemic therapy resumption/initiation among patients treated within 90 days postoperatively decreased from 35 (24-48) to 32 days (23-40; P = .074). There were no wound complications in either group.

CONCLUSION

Adjuvant SRS latency and treatment-associated encounters were significantly reduced after care-coordination implementation. This approach reduces patient and health care system burden and can be applied to other scenarios where early postoperative SRS administration is critical.

Recording of pig neuronal activity in the comparative context of the awake human brain

Gyriform mammals display neurophysiological and neural network activity that other species exhibit only in rudimentary or dissimilar form. However, neural recordings from large mammals such as the pig can be anatomically hindered and pharmacologically suppressed by anesthetics. This curtails comparative inferences. To mitigate these limitations, we set out to modify electrocorticography, intracerebral depth and intracortical recording methods to study the anesthetized pig. In the process, we found that common forms of infused anesthesia such as pentobarbital or midazolam can be neurophysiologic suppressants acting in dose-independent fashion relative to anesthetic dose or brain concentration. Further, we corroborated that standard laboratory conditions may impose electrical interference with specific neural signals. We thus aimed to safeguard neural network integrity and recording fidelity by developing surgical, anesthesia and noise reduction methods and by working inside a newly designed Faraday cage, and evaluated this from the point of view of neurophysiological power spectral density and coherence analyses. We also utilized novel silicon carbide electrodes to minimize mechanical disruption of single-neuron activity. These methods allowed for the preservation of native neurophysiological activity for several hours. Pig electrocorticography recordings were essentially indistinguishable from awake human recordings except for the small segment of electrical activity associated with vision in conscious persons. In addition, single-neuron and paired-pulse stimulation recordings were feasible simultaneously with electrocorticography and depth electrode recordings. The spontaneous and stimulus-elicited neuronal activities thus surveyed can be recorded with a degree of precision similar to that achievable in rodent or any other animal studies and prove as informative as unperturbed human electrocorticography.

Adenoid Cystic Carcinoma (ACC) Infiltrating the Skull Base: A Systematic Review of Clinical Characteristics and Management Strategies

BACKGROUND/AIM

To systematically review the patient characteristics and management approaches of adenoid cystic carcinoma (ACC) infiltrating the skull base.

MATERIALS AND METHODS

According to PRISMA guidelines, PubMed, Scopus, and Cochrane were searched to retrieve studies reporting management protocols and survival outcomes of patients with skull base ACCs. Patient characteristics, management strategies, and outcomes were investigated.

RESULTS

The review encompassed 17 studies involving 171 patients, with a female predominance (57.9%) and a mean age of 49±7.12 years. ACCs mostly infiltrated the paranasal sinus (22.2%), cavernous sinus (8.8%), and nasopharynx (7.1%). Perineural invasion was reported in 6.4% of cases. Facial pain, nasal obstruction, and facial paresthesia were the most common symptoms. Surgical resection (45.6%) was favored over biopsy (12.2%). Employing the free flap technique (4.7%), surgical reconstruction of the bony defect after resection was performed using abdominal and anterior thigh muscle grafts in 1.8% of patients each. As adjuvant management, 22.8% of cases had radiotherapy and 14.6% received chemotherapy. Recurrence of skull base ACCs occurred in 26.9% of cases during a mean follow up-time of 30.8±1.8 months.

CONCLUSION

Skull base ACCs pose a surgical challenge mainly due to their proximity to critical neurovascular structures and aggressive behavior. Surgical resection and radiotherapy are shown to be safe and effective treatment modalities. The dismal prognosis and limited data on non-surgical strategies highlight the need for further evaluation of the current management paradigm and upraising innovative therapies to improve patient mortality and quality of life.

MMAP-06 INTEGRATED TEAM-BASED BRAIN METASTASIS CARE REDUCES PATIENT VISITS AND SHORTENS TIME TO ADJUVANT IRRADIATION

PURPOSE

Timely surgical cavity stereotactic radiosurgery (SRS) is an important adjuvant to brain metastasis resection, with earlier treatment associated with less frequent recurrence. The logistical complexity of treatment organization, however, has resulted in suboptimal start times post-surgically. We implemented a team-based process improvement approach to reduce the time from surgery to adjuvant irradiation of resected brain metastases.

METHODS

A multidisciplinary working group used process-mapping to identify opportunities to reduce visits and shorten treatment times. The care delivery process was modified to streamline perioperative SRS preparation with (1) early patient identification, (2) preoperative intra-team communication, and (3) consolidation of required steps. Plan-Do-Study-Act cycles were used for process improvement. The surgery-to-SRS initiation time interval was the primary outcome. Secondary outcomes included the number of associated patient encounters.

RESULTS

Following implementation, the median (IQR) interval from surgery to SRS was reduced 48% from 27 (21,34) to 14 (13,17) days (p&lt;0.001). The rate of surgical-cavity SRS within 30 days increased from 64% (n=63/98) to 97% (n=60/62; p&lt;0.001). The median (IQR) number of CNS-associated encounters between resection and SRS decreased from 5 (4,6) to 4 (3,5; p&lt;0.001). The proportion of patients who had &gt;1 MRI/CT between surgery and SRS decreased from 45% (44/98) to 13% (8/62; p&lt;0.001). The time from surgery to systemic therapy resumption/initiation among patients treated within 90 days post-operatively decreased from 35 (24,48) to 32 days (23,40; p=0.074). There were no wound complications in either group.

CONCLUSION

Adjuvant SRS latency and treatment-associated encounters were significantly reduced after care-coordination implementation. This approach reduces patient and healthcare system burden and can be applied to other scenarios where early post-operative SRS administration is critical.

Optimizing Door-to-Groin Puncture Time: The Mayo Clinic Experience

OBJECTIVES

To provide a better understanding of methods that can be used to improve patient outcomes by reducing the door-to-groin puncture (DTP) time and present the results of a stroke quality improvement project (QIP) conducted by Mayo Clinic Arizona's stroke center.

METHODS

We conducted a systematic literature search of Ovid MEDLINE(R), Ovid EMBASE, Scopus, and Web of Science for studies that evaluated DTP time reduction strategies. Those determined eligible for the purpose of this analysis were assessed for quality. The strategies for DTP time reduction were categorized on the basis of modified Target: Stroke Phase III recommendations and analyzed using a meta-analysis. The Mayo Clinic QIP implemented a single-call activation system to reduce DTP times by decreasing the time from neurosurgery notification to case start.

RESULTS

Fourteen studies were selected for the analysis, consisting of 2277 patients with acute ischemic stroke secondary to large-vessel occlusions. After intervention, all the studies showed a reduction in the DTP time, with the pooled DTP improvement being the standardized mean difference (1.37; 95% confidence interval, 1.20-1.93; τ²=1.09; P<.001). The Mayo Clinic QIP similarly displayed a DTP time reduction, with the DTP time dropping from 125.1 to 82.5 minutes after strategy implementation.

CONCLUSION

Computed tomography flow modifications produced the largest and most consistent reduction in the DTP time. However, the reduction in the DTP time across all the studies suggests that any systematic protocol aimed at reducing the DTP time can produce a beneficial effect. The relative novelty of mechanical thrombectomy and the consequential lack of research call for future investigation into the efficacy of varying DTP time reduction strategies.

Gliomas Infiltrating the Corpus Callosum: A Systematic Review of the Literature

Background: Gliomas infiltrating the corpus callosum (G-I-CC) majorly impact patient quality-of-life, but maximally safe tumor resection is challenging. We systematically reviewed the literature on G-I-CC. Methods: PubMed, EMBASE, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies of patients with G-I-CC. Clinicopathological features, treatments, and outcomes were analyzed. Results: We included 52 studies comprising 683 patients. Most patients experienced headache (33%), cognitive decline (18.7%), and seizures (17.7%). Tumors mostly infiltrated the corpus callosum genu (44.2%) with bilateral extension (85.4%) into frontal (68.3%) or parietal (8.9%) lobes. Most G-I-CC were glioblastomas (84.5%) with IDH-wildtype (84.9%) and unmethylated MGMT promoter (53.5%). Resection (76.7%) was preferred over biopsy (23.3%), mostly gross-total (33.8%) and subtotal (32.5%). The tumor-infiltrated corpus callosum was resected in 57.8% of cases. Radiation was delivered in 65.8% of patients and temozolomide in 68.3%. Median follow-up was 12 months (range, 0.1−116). In total, 142 patients (31.8%) experienced post-surgical complications, including transient supplementary motor area syndrome (5.1%) and persistent motor deficits (4.3%) or abulia (2.5%). Post-treatment symptom improvement was reported in 42.9% of patients. No differences in rates of complications (p = 0.231) and symptom improvement (p = 0.375) were found in cases with resected versus preserved corpus callosum. Recurrences occurred in 40.9% of cases, with median progression-free survival of 9 months (0.1−72). Median overall survival was 10.7 months (range, 0.1−116), significantly longer in low-grade tumors (p = 0.013) and after resection (p < 0.001), especially gross-total (p = 0.041) in patients with high-grade tumors. Conclusions: G-I-CC show clinicopathological patterns comparable to other more frequent gliomas. Maximally safe resection significantly improves survival with low rates of persistent complications.

Percutaneous screw fixation versus open fusion for the treatment of traumatic thoracolumbar fractures: A retrospective case series of 185 Patients with a single-level spinal column injury

STUDY DESIGN

Retrospective Single-Center Review of Data at a Level 1 Trauma Center.

OBJECTIVE

Compare deformity correction and surgical outcomes of percutaneous instrumentation and open fusion in traumatic thoracolumbar fractures.

METHODS

In our retrospective study, all patients undergoing elective spine surgery for TL fractures at a Level 1 trauma center between 2000 and 2017 were reviewed. Patients who underwent percutaneous fixation were given the option of hardware removal after the fracture had healed.

RESULTS

A total of 185 patients were included in the study, with 109 treated with an open fusion, and 76 with percutaneous fixation. Twenty-five patients in the latter group had the instrumentation removed after the fracture had healed. None of them required reoperation. In the open fusion group 54.1% of patients required a decompressive laminectomy. Percutaneous fixation patients had a shorter operative time (98.3 min vs 214 min, p < 0.0001), shorter length of stay (9.8 days vs 13.5 days, p = 0.04), and less blood loss (68.4 cc vs 691 cc, p < 0.001). They also had a better correction of their traumatic kyphosis after surgery (p = 0.005).

CONCLUSION

Percutaneous fixation is a valuable option for the treatment of TL fractures in cases without evidence of neural compression. It is still unclear whether hardware removal helps prevent adjacent segment degeneration. Percutaneous fixation could allow for better reduction of the fracture with improvement of postoperative alignment.

Pancreatic Cancer Metastasis to the Spine: A Systematic Review of Management Strategies and Outcomes with Case Illustration

OBJECTIVE

We aim to provide a thorough review of the literature regarding patient characteristics, treatment options, and outcomes of pancreatic cancer metastasis to the spine. We also provide an illustrative case from our institution of a patients with pancreatic adenocarcinoma presenting initially as cervical radiculopathy with an isolated cervical spine lesion.

METHODS

Using the PRISMA guidelines, the literature in PubMed, Google Scholar, and Web of Science databases was searched. We excluded systematic reviews and meta-analyses that did not provide novel cases, as well as reports of metastatic disease from other nonpancreatic primary cancers.

RESULTS

Thirty-two patients across 21 studies met the inclusion criteria. The patients were predominantly male (58%), with a mean age of 59 years. Of patients, 64% presented with back pain, 39% with motor deficits, and 15% with bladder or bowel dysfunction. For treatment, chemotherapy was used in 55% of cases and radiotherapy in 42%. Surgical treatment was performed in 42% of cases, with complete tumor resection achieved in 24% of cases. The mean patient survival after treatment was 28 weeks (range, 1-83 weeks), with patients undergoing treatment involving surgery having increased survival (44 weeks) compared with noninvasive treatment alone (18 weeks).

CONCLUSIONS

Spinal metastasis of pancreatic cancer is rare and typically portends a poor prognosis. It is vital to recognize the presence of spinal involvement early in the disease course and initiate treatment.

Metastases in the Pineal Region: A Systematic Review of Clinical Features, Management Strategies, and Survival Outcomes

BACKGROUND

Pineal region metastases are rare but often cause severe neurologic deficits. Surgical resection and chemoradiotherapy can provide therapeutic benefit. We investigated the literature to analyze clinical characteristics, management strategies, and survival of adult patients with pineal region metastases.

METHODS

PubMed, Embase, Scopus, and Cochrane were searched following the PRISMA guidelines, including studies reporting clinical outcomes of patients with pineal region metastases. Clinical presentation, management, and survival were reviewed.

RESULTS

We included 31 studies comprising 47 patients. Lung cancer (29.8%) and carcinomas of unknown origin (14.9%) were the most frequent primary tumors. In 48.9% of patients, symptomatic pineal metastases preceded primary tumor diagnosis. Headache (67.4%) and confusion (46.5%) were the most common symptoms. Parinaud syndrome (46.5%) and hydrocephalus (87.2%) were noted. Biopsy (65.9%) was preferred over resection (34.1%), and shunting strategies used were endoscopic third ventriculostomy (43.9%) and ventriculoperitoneal (26.8%). Eleven patients (32.3%) received adjuvant chemotherapy and 32 (68%) received radiotherapy. Posttreatment improvement in symptoms (56.6%) and hydrocephalus (80.5%) were noted. In patients who received adjuvant chemotherapy/radiotherapy, significant improvement in posttreatment performance status occurred with both biopsy (P < 0.001) and resection (P = 0.007). No survival differences were reported between surgery and biopsy (P = 0.912) or between complete and partial resection (P = 0.220). Overall survival was neither influenced by surgical approach (P = 0.157) nor by shunting strategy (P = 0.822). Mean follow-up was 8 months and median overall survival 3 months. Only 2 cases (4.8%) of pineal metastasis showed recurrence.

CONCLUSIONS

Pineal region metastases carry significant morbidity. Biopsy or surgical resection, combined with adjuvant chemotherapy/radiotherapy and/or shunting, may significantly improve performance status.

Transfusion guidelines in adult spine surgery: a systematic review and critical summary of currently available evidence

BACKGROUND CONTEXT

Red blood cell transfusion can be associated with complications in medical and surgical patients. Acute anemia in ambulatory patients undergoing surgery can also impede wound healing and independent self-care. Current transfusion threshold guidelines are still based on evidence derived from critically-ill intensive care unit medical patients and may not apply to spine surgery candidates.

PURPOSE

We aimed to provide the reader with a synthesis of the best available evidence to recommend transfusion trigger thresholds and guidelines in adult patients undergoing spine surgery.

STUDY DESIGN/SETTING

This is a systematic review.

OUTCOME MEASURES

Physiological measure: Blood transfusion thresholds and associated posttransfusion complications (morbidity, mortality, length of stay, infections, etc) of the published articles.

PATIENT SAMPLE

Adult spine surgery patients.

METHODS

A systematic review of the literature using the PubMed, Google Scholar, and Web of Science electronic databases was made according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Focus was set on papers discussing thresholds for blood transfusion in adult surgical spine patients, as well as complications associated with transfusion after acute surgical blood loss in the operating room or postoperative period. Publications discussing pediatric cases, blood type analyses, blood loss prevention strategies and protocols, systematic reviews and letters to the editor were excluded.

RESULTS

A total of 22 articles fitting our search criteria were reviewed. Patients who received blood transfusion in these studies were older, of female gender, had more severe comorbidities except for smoking, and had prolonged surgical time. Blood transfusion was associated with multiple adverse postoperative complications, including a higher rate of superficial or deep surgical site infections, sepsis, urinary and pulmonary infections, cardiovascular complications, return to the operating room, and increased postoperative length of stay and 30 day readmission. Analysis of transfusion thresholds from these studies showed that a pre-operative hemoglobin (Hb) of > 13 g/dL, and an intraoperative and post-operative Hb nadir above 9 and 8 g/dL, respectively, were associated with better outcomes and fewer wound infections than lower thresholds (Level B Class III). Additionally, it was generally recommended to transfuse autologous blood that was < 28 days old, if possible, with a limit of 2 to 3 units to minimize patient morbidity and mortality.

CONCLUSIONS

Blood transfusion thresholds in surgical patients may be specialty-specific and different than those used for critically-ill medical patients. For adult spine surgery patients, red blood cell transfusion should be avoided if Hb numbers remain > 9 and 8 g/dL in the intraoperative and direct post-operative periods, respectively.

Distant Pituitary Adenoma Spread: A Systematic Review and Report of 2 Cases

BACKGROUND

Distant spread of pituitary adenoma outside the sellar/suprasellar region is classified as pituitary carcinoma. Cerebrospinal fluid (CSF)-born spread of pituitary adenoma can occur after tumor cell spillage into the CSF space after surgery, irradiation, or apoplexy and is not necessarily related to intrinsic tumor biology.

OBJECTIVE

To systematically review the literature and describe the clinical characteristics and treatment strategies of patients with pituitary carcinomas. We further present 2 cases from our institution.

METHODS

A single-center retrospective review of patients with pituitary adenoma spread to distant intracranial locations between 2000 and 2020 was performed. Electronic databases were searched from their inception to May 25, 2021, and studies describing patients with pituitary spread to distant locations were included.

RESULTS

Of 1210 pituitary adenoma cases reviewed, 2 (0.16%) showed tumor spread to distant locations. We found 134 additional cases (from 108 published articles) resulting in a total of 136 cases (61.9% were male). The time to tumor spread ranged between 0 and 516 months (median: 96 months). The follow-up duration ranged between 0 and 240 months (median: 11.5 months). All but 2 patients (98.5%) underwent surgical resection before adenoma spread. The 2 exceptions included a patient with evidence of an apoplectic event on autopsy and another patient with leptomeningeal pituitary spread but an unclear history of apoplexy. Elevated tumor markers were not linked to poor outcomes.

CONCLUSION

Distant spread of pituitary adenoma may occur after surgery, irradiation, or apoplexy. It is not necessarily associated with a malignant clinical course.

Imaging characteristics of 4th ventricle subependymoma

PURPOSE

Subependymomas located within the 4th ventricle are rare, and the literature describing imaging characteristics is sparse. Here, we describe the clinical and radiological characteristics of 29 patients with 4th ventricle subependymoma.

METHODS

This is a retrospective multi-center study performed after Institutional Review Board (IRB) approval. Patients diagnosed with suspected 4th ventricle subependymoma were identified. A review of clinical, radiology, and pathology reports along with magnetic resonance imaging (MRI) images was performed.

RESULTS

Twenty-nine patients, including 6 females, were identified. Eighteen patients underwent surgery with histopathological confirmation of subependymoma. The median age at diagnosis was 52 years. Median tumor volume for the operative cohort was 9.87 cm³, while for the non-operative cohort, it was 0.96 cm³. Thirteen patients in the operative group exhibited symptoms at diagnosis. For the total cohort, the majority of subependymomas (n = 22) were isointense on T1, hyperintense (n = 22) on T2, and enhanced (n = 24). All tumors were located just below the body of the 4th ventricle, terminating near the level of the obex. Fourteen cases demonstrated extension of tumor into foramen of Magendie or Luschka.

CONCLUSION

To the best of our knowledge, this is the largest collection of 4th ventricular subependymomas with imaging findings reported to date. All patients in this cohort had tumors originating between the bottom of the body of the 4th ventricle and the obex. This uniform and specific site of origin aids with imaging diagnosis and may infer possible theories of origin.

Transfusion Guidelines in Traumatic Brain Injury: A Systematic Review and Meta-Analysis of the Currently Available Evidence

Our study aims to provide a synthesis of the best available evidence on the hemoglobin (hgb) red blood cell (RBC) transfusion thresholds in adult traumatic brain injury (TBI) patients, as well as describing the risk factors and outcomes associated with RBC transfusion in this population. A systematic review and meta-analysis was conducted using PubMed, Google Scholar, and Web of Science electronic databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to assess articles discussing RBC transfusion thresholds and describe complications secondary to transfusion in adult TBI patients in the perioperative period. Fifteen articles met search criteria and were reviewed for analysis. Compared to non-transfused, TBI patients who received transfusion tended to be primarily male patients with worse Injury Severity Score (ISS) and Glasgow Coma Scale. Further, the meta-analysis corroborated that transfused TBI patients are older (p = 0.04), have worse ISS scores (p = 0.001), receive more units of RBCs (p = 0.02), and have both higher mortality (p < 0.001) and complication rates (p < 0.0001). There were no differences identified in rates of hypertension, diabetes mellitus, and Abbreviated Injury Scale scores. Additionally, whereas many studies support restrictive (hgb <7 g/dL) transfusion thresholds over liberal (hgb <10 g/dL), our meta-analysis revealed no significant difference in mortality between those thresholds (p = 0.79). Current Class B/C level III evidence predominantly recommends against a liberal transfusion threshold of 10 g/dL for TBI patients (Class B/C level III), but our meta-analysis found no difference in survival between groups. There is evidence suggesting that an intermediate threshold between 7 and 9 g/dL, reflecting the physiological oxygen needs of cerebral tissue, may be worth exploring.

Orbital Metastases: A Systematic Review of Clinical Characteristics, Management Strategies, and Treatment Outcomes

BACKGROUND

Orbital metastases often lead to severe functional impairment. The role of resection, orbital exenteration, and complementary treatments is still debated. We systematically reviewed the literature on orbital metastases.

METHODS

PubMed, Scopus, Web-of-Science, and Cochrane were searched upon PRISMA guidelines to identify studies on orbital metastases. Clinical characteristics, management strategies, and survival were analyzed.

RESULTS

We included 262 studies comprising 873 patients. Median age was 59 years. The most frequent primary tumors were breast (36.3%), melanoma (10.1%), and prostate (8.5%) cancers, with median time interval of 12 months (range, 0-420). The most common symptoms were proptosis (52.3%) and relative-afferent-pupillary-defect (38.7%). Most metastases showed a diffuse location within the orbit (19%), with preferential infiltration of orbital soft tissues (40.2%). In 47 cases (5.4%), tumors extended intracranially. Incisional biopsy (63.7%) was preferred over fine-needle aspiration (10.2%), with partial resection (16.6%) preferred over complete (9.5%). Orbital exenteration was pursued in 26 patients (3%). A total of 305 patients (39.4%) received chemotherapy, and 506 (58%) received orbital radiotherapy. Post-treatment symptom improvement was significantly superior after resection (p = 0.005) and orbital radiotherapy (p = 0.032). Mean follow-up was 14.3 months, and median overall survival was 6 months. Fifteen cases (1.7%) demonstrated recurrence with median local control of six months. Overall survival was statistically increased in patients with breast cancer (p < 0.001) and in patients undergoing resection (p = 0.024) but was not correlated with orbital location (p = 0.174), intracranial extension (p = 0.073), biopsy approach (p = 0.344), extent-of-resection (p = 0.429), or orbital exenteration (p = 0.153).

CONCLUSIONS

Orbital metastases severely impair patient quality of life. Surgical resection safely provides symptom and survival benefit compared to biopsy, while orbital radiotherapy significantly improves symptoms compared to not receiving radiotherapy.

Hydrocephalus in achondroplasia: efficacy of endoscopic third ventriculostomy

OBJECTIVE

Ventriculoperitoneal shunts (VPSs) for hydrocephalus in patients with achondroplasia are known to have a higher failure rate than in other hydrocephalus populations. However, the etiology of hydrocephalus in this group is considered "communicating," and, therefore, potentially not amenable to endoscopic third ventriculostomy (ETV). ETV has, nonetheless, been reported to be successful in a small number of patients with achondroplasia. The authors aimed to investigate the long-term results of ETV in this population.

METHODS

Patients with achondroplasia who had undergone surgical treatment for hydrocephalus (ETV or VPS placement) were identified. In patients who had undergone ETV, medical records and neuroimages were reviewed to determine ventricular volumes and frontal and occipital horn ratios (FOHRs) pre- and postoperatively, as well as the incidence of surgical complications and reoperation. Patients who underwent VPS placement were included for historical comparison, and their medical records were reviewed for basic demographic information as well as the incidence of surgical complications and reoperation.

RESULTS

Of 114 pediatric patients with achondroplasia referred for neurosurgical consultation, 19 (17%) were treated for hydrocephalus; 10 patients underwent ETV only, 7 patients underwent VPS placement only, and 2 patients had a VPS placed followed by ETV. In patients treated with ETV, ventricular volume and FOHRs were normal, if measured at birth, and increased significantly until the time of the ETV. After ETV, all patients demonstrated significant and sustained decreases in ventricular measurements with surveillance up to 15 years. There was a statistically significant difference in rates of repeat CSF surgery between the ETV and VPS cohorts (0/12 vs 7/9, p < 0.001).

CONCLUSIONS

ETV was efficacious, safe, and durable in the treatment of hydrocephalus in patients with achondroplasia. Although many studies have indicated that hydrocephalus in these patients is "communicating," a subset may develop an "obstructive" component that is progressive and responsive to ETV.

Postoperative Transfusion Guidelines in Aneurysmal Cerebral Subarachnoid Hemorrhage: A Systematic Review and Critical Summary of Available Evidence

OBJECTIVE

Surgical management of aneurysmal subarachnoid hemorrhage (SAH) often involves red blood cell (RBC) transfusion, which increases the risk of postoperative complications. RBC transfusion guidelines report on chronically critically ill patients and may not apply to patients with SAH. Our study aims to synthesize the evidence to recommend RBC transfusion thresholds among adult patients with SAH undergoing surgery.

METHODS

A systematic review was conducted using PubMed, Google Scholar, and Web of Science electronic databases according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to critically assess primary articles discussing RBC transfusion thresholds and describe complications secondary to RBC transfusion in adult patients with SAH in the perioperative period.

RESULTS

Sixteen articles meeting our search strategy were reviewed. Patients with SAH who received blood transfusion were older, female, had World Federation of Neurosurgical Societies grade IV-V and modified Fisher grade 3-4 scores, and presented with more comorbidities such as hypertension, diabetes, and cardiovascular and pulmonary diseases. In addition, transfusion was associated with multiple postoperative complications, including higher rates of vasospasms, surgical site infections, cardiovascular and respiratory complications, increased postoperative length of stay, and 30-day mortality. Analysis of transfused patients showed that a higher hemoglobin (>10 g/dL) goal after SAH was safe and that patients may benefit from a higher whole hospital stay hemoglobin nadir, as shown by a reduction in risk of cerebral vasospasm and improvement in clinical outcomes (level B class II).

CONCLUSIONS

Among patients with SAH, the benefits of reducing cerebral ischemia and anemia are shown to outweigh the risks of transfusion-related complications.

Thalamic gliomas in adults: a systematic review of clinical characteristics, treatment strategies, and survival outcomes

PURPOSE

Thalamic gliomas are rare neoplasms that pose significant surgical challenges. The literature is limited to single-institution retrospective case series. We systematically review the literature and describe the clinical characteristics, treatment strategies, and survival outcomes of adult thalamic gliomas.

METHODS

Relevant articles were identified on PubMed, Scopus, and Cochrane databases. Papers containing cases of adult thalamic gliomas with clinical outcome data were included. A comprehensive review of clinical characteristics and survival analysis was conducted.

RESULTS

We included 25 studies comprising 617 patients. The median age was 45 years (male = 58.6%). Glioblastoma was the most frequent histological type (47.2%), and 82 tumors were H3 K27M-mutant. Motor deficit was the most common presenting symptom (51.8%). Surgical resection was performed in 69.1% of cases while adjuvant chemotherapy and radiotherapy were administered in 56.3% and 72.6%, respectively. Other treatments included laser interstitial thermal therapy, which was performed in 15 patients (2.4%). The lesion laterality (P = 0.754) and the surgical approach (P = 0.111) did not correlate with overall survival. The median progression-free survival was 9 months, and the overall two-year survival rate was 19.7%. The two-year survival rates of low-grade and high-grade thalamic gliomas were 31.0% and 16.5%, respectively. H3 K27M-mutant gliomas showed worse overall survival (P = 0.017).

CONCLUSION

Adult thalamic gliomas are associated with poor survival. Complete surgical resection is associated with improved survival rates but is not always feasible. H3 K27M mutation is associated with worse survival and a more aggressive approach should be considered for mutant neoplasms.

Blood preservation techniques in complex spine surgery: Illustrative case and review of therapeutic options

Background:

Complex spine surgery predisposes patients to substantial levels of blood loss, which can increase the risk of surgical morbidity and mortality.

Case Description:

A 29-year-old achondroplastic male required thoracolumbar deformity correction. However, he refused potential allogeneic blood transfusions for religious reasons. He, therefore, underwent pre-operative autologous blood donation and consented to the use of the intraoperative cell salvage device. Immediately prior to the incision, he underwent acute normovolemic hemodilution. Throughout the case, we additionally utilized meticulous hemostasis. Postoperatively, he was supplemented with iron and erythropoietin and recovered well. When he required a revision procedure 3 months later, similar strategies were successfully employed.

Conclusion:

Numerous strategies exist pre-operatively, intraoperatively, and post-operatively to optimize blood loss management for patients who refuse blood transfusions but warrant major spinal deformity surgery.

The Role of Immune Checkpoint Inhibitors in Leptomeningeal Disease: A Systematic Review

BACKGROUND/AIM

Leptomeningeal disease (LMD) is a debilitating complication of advanced malignancies. Immune-checkpoint inhibitors (ICIs) may alter disease course. We analyzed the role and toxicity of ICIs in LMD.

MATERIALS AND METHODS

We systematically reviewed the literature reporting on outcome data of patients with LMD treated with ICIs.

RESULTS

We included 14 studies encompassing 61 patients. Lung-cancer (44.3%), breast-cancer (27.9%), and melanoma (23.0%) were the most frequent primary tumors. Median duration of ICI-treatment was 7-months (range=0.5-58.0): pembrolizumab (49.2%), nivolumab (32.8%), ipilimumab (18.0%). Radiological responses included complete response (33.3%), partial response (12.5%), stable disease (33.3%), progressive disease (20.8%). Twenty-two patients developed ICI-related adverse-events, mild (100%) and/or severe (15.6%). Median progression-free and overall survival were 5.1 and 6.3 months, and 12-month survival was 32.1%. Survival correlated with ICI agents (p=0.042), but not with primary tumors (p=0.144). Patients receiving concurrent steroids showed worse survival (p=0.040).

CONCLUSION

ICI therapy is well-tolerated in patients with LMD, but concurrent steroids may worsen survival.

Large Animal Models of Glioma: Current Status and Future Prospects

Enhanced understanding of the molecular features of glioma has led to an expansion of murine glioma models and successful preclinical studies. However, clinical trials continue to have a high cost, extended production time, and low proportion of success. Studies in large-animal models of various cancer types have emerged to bridge the translational gap between in vitro and in vivo animal studies and human clinical trials. The anatomy and physiology of large animals are of more direct relevance to human disease, allowing for more rigorous testing of treatments such as surgical resection and adjuvant therapy in glioma. The recent generation of multiple porcine glioma models supports their use in high-throughput preclinical studies. The demonstration of spontaneous glioblastoma formation in canines further provides a unique avenue for the study of de novo glioma. The aim of this review was to outline the current status of large animal models of glioma and their value as a transitional step between rodent models and human clinical trials.

The Far-Lateral Suboccipital Approach to the Lesions of the Craniovertebral Junction

The far-lateral suboccipital approach and its variants, including the transcondylar, supracondylar, and paracondylar approaches, are essential skull base techniques for the neurosurgeon to expose and treat pathologies located at the ventral and ventrolateral craniovertebral junction. An understanding of the surgical anatomy and technical nuances of these approaches is vital for preventing catastrophic brainstem or spinal cord injury, neurovascular injury, and/or cranial nerve injury. This is achieved by carefully studying the location, the rostral-caudal and lateral extents of the lesion itself, and the anatomy of the surrounding structures on preoperative imaging. The amount of bony exposure should be tailored to each specific lesion to avoid unnecessary bone drilling and therefore decrease the risk of potential craniocervical instability. Minimizing retraction of the cerebellum, brainstem, and spinal cord is important for preventing neurologic injury; therefore, appropriate intraoperative head positioning and adequate bony exposure should be ensured, especially for more ventrally located lesions. A thorough knowledge of the anatomy of the extradural and intradural segments of the vertebral artery, and the lower cranial nerves, in relation to the lesion is also critical. For almost all lesions, the far-lateral suboccipital route with no or minimal condylar drilling is more than adequate for removing the most ventral lesions. Herein, we discuss the indications, general and preoperative considerations, and surgical anatomy and technical nuances of this approach.

Impact of Insurance Provider on Postoperative Hospital Length of Stay After Spine Surgery

OBJECTIVE

Differences in insurer and payer status have been shown to increase patient hospital length of stay (LOS) by delaying the approval of transfer to a rehabilitation facility. The aim of the current study is to determine the impact of the type of insurance provider on postoperative hospital LOS after spine surgery.

METHODS

In our single-institution retrospective study, all patients undergoing elective spine surgery between August 2018 and August 2019 as part of an enhanced recovery after surgery (ERAS) protocol were enrolled in a prospectively collected registry. Insurance payer type was analyzed to determine its effect on total patient LOS after surgery.

RESULTS

A total of 106 patients were included in the study. Insurance payers studied were Medicare, private insurers (preferred provider organization and health maintenance organization), and the Veterans Affairs payer TriWest. Patients in all groups had comparable demographic characteristics and procedural variables. There was a statistically significant difference in days stayed beyond medical clearance among the 3 insurance provider groups (P < 0.001); TriWest patients stayed an average of 3.2 days beyond clearance, compared with private insurance (1.2 days) and Medicare (0.3 days). Individual subanalysis of the ERAS complex pathway population mirrored these findings.

CONCLUSIONS

Hospitalization beyond medical clearance after spine surgery follows a predictable pattern regardless of ERAS pathway complexity, with Medicare having a shorter delay in approving patient progression than private insurance, which has less of a delay than Triwest.

RADI-14. Bevacizumab vs Laser Interstitial Thermal Therapy in radiation necrosis from brain metastases: a systematic review and meta-analysis

Objective

Radiation necrosis (RN) represents a serious post-radiotherapy complication in patients with brain metastases. Bevacizumab and laser interstitial thermal therapy (LITT) are viable treatment options, but direct comparative data is scarce. We reviewed the literature to compare the two treatment strategies.

Methods

PubMed, EMBASE, Scopus, and Cochrane databases were searched. All studies of patients with RN from brain metastases treated with bevacizumab or LITT were included. Treatment outcomes were analyzed using indirect meta-analysis with random-effect modeling.

Results

Among the 18 studies included, 143 patients received bevacizumab and 148 underwent LITT. Both strategies were equally effective in providing post-treatment symptomatic improvement (P=0.187, I2=54.8%), weaning off steroids (P=0.614, I2=25.5%), and local lesion control (P=0.5, I2=0%). The mean number of lesions per patient was not statistically significant among groups (P=0.624). Similarly, mean T1-contrast-enhancing pre-treatment volumes were not statistically different (P=0.582). Patterns of radiological responses differed at 6-month follow-ups, with rates of partial regression significantly higher in the bevacizumab group (P=0.001, I2=88.9%), and stable disease significantly higher in the LITT group (P=0.002, I2=81.9%). Survival rates were superior in the LITT cohort, and statistical significance was reached at 18 months (P=0.038, I2=73.7%). Low rates of adverse events were reported in both groups (14.7% for bevacizumab and 12.2% for LITT).

Conclusion

Bevacizumab and LITT can be safe and effective treatments for RN from brain metastases. Clinical and radiological outcomes are mostly comparable, but LITT may relate to superior survival benefits in select patients. Further studies are required to identify the best patient candidates for each treatment group.

LMD-10. The role of immune checkpoint inhibitors in leptomeningeal disease: a systematic review

Background

Leptomeningeal disease (LMD) is a devastating complication of advanced malignancy with a poor prognosis and limited therapeutic options. Whether immune checkpoint inhibitors (ICIs) alter disease course is unknown.

Methods

We searched PubMed, EMBASE, Scopus, Cochrane, and clinicaltrials.gov according to PRISMA guidelines to analyze the therapeutic role and toxicity profiles of ICIs in the management of LMD. Studies reporting clinical outcome data of patients with LMD treated with ICIs were included. A comprehensive review of clinical characteristics and survival analysis was conducted.

Results

We included 14 studies encompassing 61 patients. The median age at LMD diagnosis was 57 years (female=63.9%). Lung cancer (44.3%), breast cancer (27.9%), and melanoma (23.0%) were the most frequent primary tumors. Parenchymal brain metastases occurred in 37 patients, mostly treated with radiotherapy (83.3%). LMD most frequently presented with headache (42.1%) and was diagnosed by MRI findings (leptomeningeal T1-contrast enhancement: 96.7%) and/or positive cerebrospinal fluid cytology (86.5%). Patients received ICIs for a median duration of 7 months (range, 0.5–58.0): pembrolizumab (49.2%), nivolumab (32.8%), and/or ipilimumab (18.0%). The most common concurrent LMD treatments were radiotherapy (54.7%) and steroids (35.7%). Radiological responses at 6-months were complete (33.3%) and partial response (12.5%), stable disease (33.3%), and progression (20.8%). 22 patients developed ICI-related adverse events, mostly mild (100%) and uncommonly severe (15.6%). Median progression-free survival was 5.1 months, median overall survival was 6.3 months, and 12-month survival was 32.1%. Survival was correlated with ICIs (P=0.042), but not with primary tumors (P=0.144). Patients concurrently receiving steroids showed worse survival (P=0.040), with a median overall survival of 1.9 months.

Conclusion

ICI therapy shows promise and appears to be well-tolerated in patients with LMD. Concurrent use of steroids is associated with worse survival. The role of ICIs in the multimodal management of LMD and their combination with steroids requires further analysis.

SURG-06. Metastases in the pineal region: a systematic review of clinical features, treatment strategies and survival outcomes

Background

Pineal region metastases are rare but often lead to severe neurological deficits. Surgical resection may play a therapeutic role.

Methods

We searched PubMed, EMBASE, Scopus, and Cochrane according to PRISMA guidelines. Studies reporting clinical outcomes data of patients with pineal region metastases were included. Clinical characteristics, management strategies, and survival data were reviewed.

Results

We included 30 studies comprising 46 patients. The median age at diagnosis was 58 years (range 27–82). Lung cancer (30.4%) and carcinomas of unknown origin (15.2%) were the most frequent primary tumors. In 50% of patients, symptomatic pineal metastases preceded primary tumor diagnosis. Headache (66.7%) and confusion (45.2%) were the most common presenting symptoms. Parinaud’s syndrome (47.6%) and hydrocephalus (87%) were commonly noted. Biopsy (67.4%) was preferred over surgical resection (32.6%). The most common CSF diversion protocols were endoscopic third ventriculostomy (45%) and ventriculoperitoneal shunting (27.5%). Eleven patients received adjuvant chemotherapy and 31 underwent radiotherapy. At post-treatment follow-up, symptomatic improvement (55.2%) and hydrocephalus reduction (80%) were described. Post-treatment performance status scores were statistically superior that pre-treatment scores for patients undergoing biopsy (P<0.001) and tumor resection (P=0.007) coupled with adjuvant chemo/radiotherapy. Mean follow-up was 8 months, and median overall survival was 3 months. Only two cases (4.8%) of pineal metastases recurrence were reported, and median progression-free survival was 3 months. In patients receiving adjuvant chemo/radiotherapy, no survival differences were reported between surgery and biopsy (P=0.912), nor between gross-total and subtotal resection (P=0.220). Overall survival was neither correlated with surgical approach (P=0.157), nor with CSF diversion protocol (P=0.822).

Conclusion

Pineal region metastases can severely impair clinical status. Biopsy or surgical resection may significantly improve symptoms and baseline performance status when combined with adjuvant chemo/radiotherapy and CSF diversion.

Bevacizumab vs laser interstitial thermal therapy in cerebral radiation necrosis from brain metastases: a systematic review and meta-analysis

PURPOSE

Radiation necrosis (RN) represents a serious post-radiotherapy complication in patients with brain metastases. Bevacizumab and laser interstitial thermal therapy (LITT) are viable treatment options, but direct comparative data is scarce. We reviewed the literature to compare the two treatment strategies.

METHODS

PubMed, EMBASE, Scopus, and Cochrane databases were searched. All studies of patients with RN from brain metastases treated with bevacizumab or LITT were included. Treatment outcomes were analyzed using indirect meta-analysis with random-effect modeling.

RESULTS

Among the 18 studies included, 143 patients received bevacizumab and 148 underwent LITT. Both strategies were equally effective in providing post-treatment symptomatic improvement (P = 0.187, I² = 54.8%), weaning off steroids (P = 0.614, I² = 25.5%), and local lesion control (P = 0.5, I² = 0%). Mean number of lesions per patient was not statistically significant among groups (P = 0.624). Similarly, mean T1-contrast-enhancing pre-treatment volumes were not statistically different (P = 0.582). Patterns of radiological responses differed at 6-month follow-ups, with rates of partial regression significantly higher in the bevacizumab group (P = 0.001, I² = 88.9%), and stable disease significantly higher in the LITT group (P = 0.002, I² = 81.9%). Survival rates were superior in the LITT cohort, and statistical significance was reached at 18 months (P = 0.038, I² = 73.7%). Low rates of adverse events were reported in both groups (14.7% for bevacizumab and 12.2% for LITT).

CONCLUSION

Bevacizumab and LITT can be safe and effective treatments for RN from brain metastases. Clinical and radiological outcomes are mostly comparable, but LITT may relate with superior survival benefits in select patients. Further studies are required to identify the best patient candidates for each treatment group.

Comparison of Blister Aneurysm Treatment Techniques: A Systematic Review and Meta-Analysis

OBJECTIVE

Blood blister aneurysms are small, thin-walled, rapidly growing side-wall aneurysms that have proved particularly difficult to treat, and evidence-based guidance for treatment strategies is lacking. A systematic review and meta-analysis was performed to aggregate the available data and compare the 3 primary treatment modalities.

METHODS

We performed a comprehensive literature search according to PRISMA guidelines followed by an indirect meta-analysis that compares the safety and efficacy of surgical, flow-diverting stents (FDS), and other endovascular approaches for the treatment of ruptured blood blister aneurysms.

RESULTS

A total of 102 studies were included for quantitative synthesis, with sample sizes of 687 treated surgically, 704 treated endovascularly without FDS, and 125 treated via flow diversion. Comparatively, FDS achieved significantly reduced rates of perioperative retreatment compared with both surgical (P = 0.025) and non-FDS endovascular (P < 0.001). The FDS subgroup also achieved a significantly lower incidence of perioperative rebleed (P < 0.001), perioperative hydrocephalus (P = 0.012), postoperative infarction (P = 0.002), postoperative hydrocephalus (P < 0.001), and postoperative vasospasm (P = 0.002) compared with those patients in the open surgical subgroup. Although no significant differences were found among groups on the basis of functional outcomes, angiographic outcomes detailed by rates of radiographic complete occlusion were highest for surgical (90.7%, 262/289) and FDS (89.1%, 98/110) subgroups versus the non-FDS endovascular subgroup (82.7%, 268/324).

CONCLUSIONS

Flow diversion seems to be an effective treatment strategy for ruptured blood blister aneurysms, with lower rates of perioperative complications compared with surgical and other endovascular techniques, but studies investigating long-term outcomes after flow diversion warrant further study.

Quantitative pupillometry in patients with traumatic brain injury and loss of consciousness: A prospective pilot study

OBJECTIVE

Loss of consciousness (LOC) is a hallmark feature in Traumatic Brain Injury (TBI), and a strong predictor of outcomes after TBI. The aim of this study was to describe associations between quantitative infrared pupillometry values and LOC, intracranial hypertension, and functional outcomes in patients with TBI.

METHODS

We conducted a prospective study of patients evaluated at a Level 1 trauma center between November 2019 and February 2020. Pupillometry values including the Neurological Pupil Index (NPi), constriction velocity (CV), and dilation velocity (DV) were obtained.

RESULTS

Thirty-six consecutive TBI patients were enrolled. The median (range) age was 48 (range 21-86) years. The mean Glasgow Coma Scale score on arrival was 11.8 (SD = 4.0). DV trichotomized as low (<0.5 mm/s), moderate (0.5-1.0 mm/s), or high (>1.0 mm/s) was significantly associated with LOC (P = .02), and the need for emergent intervention (P < .01). No significant association was observed between LOC and NPi (P = .16); nor between LOC and CV (P = .07).

CONCLUSIONS

Our data suggests that DV, as a discrete variable, is associated with LOC in TBI. Further investigation of the relationship between discrete pupillometric variables and NPi may be valuable to understand the clinical significance of the pupillary light reflex findings in acute TBI.

Bertolotti Syndrome With Articulated L5 Transverse Process Causing Intractable Back Pain: Surgical Video Showcasing a Minimally Invasive Approach for Disconnection: 2-Dimensional Operative Video

Bertolotti syndrome is a commonly missed cause of intractable back pain that affects 4% to 8% of the general population. It involves the congenital malformation of a transitional lumbosacral vertebra, with total or partial and unilateral or bilateral transverse process (TP) fusion or articulation to the sacrum. The pain can be debilitating, and the tethering of the spine to the sacrum can encourage deformity formation in the coronal plane and lead to early degenerative changes, especially if present only unilaterally. We present the case of a 24-yr-old woman with no notable prior medical history who presented with years of lower axial back pain radiating to her thighs, which limited her activities of daily living and was resistant to conservative management. Her imaging showed an abnormally large left L5 TP, which was articulated to the sacrum, and signs of early coronal deformity. She had responded almost completely to repeated steroid injections into the TP-sacral joint, but that effect was very transient. Informed patient consent was obtained prior to her surgery. She underwent a minimally invasive tube disconnection of the abnormal joint with partial distal resection of the TP, and her symptoms completely resolved. This case highlights the importance of correlating clinical symptoms with aberrant anatomy, and the role of selective surgery in providing symptomatic relief. This case report was written in compliance with our institutional ethical review board approval, and patient consent was waived in light of the retrospective and deidentified nature of the data presented in accordance with the University of Texas Southwestern institutional review board.