Treatment of Endovascular Coil and Stent Migration Using the Merci Retriever: Report of Three Cases

Background. Coil and stent migration is a potentially catastrophic complication in endovascular neurosurgery, which may lead to cerebral thromboembolism. Techniques for removing migrated coil and stent are not well established. Methods and Results. We present three cases in which coil or stent migration occurred during endovascular embolization of a cerebral aneurysm. The Merci Retrievers were used successfully in all cases to remove the displaced foreign bodies. Technical details are described. Conclusion. The Merci Retriever device can be utilized successfully for removal of migrated coils and stents in endovascular neurosurgery

Federated learning enables big data for rare cancer boundary detection.

Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing

Author Correction: Federated learning enables big data for rare cancer boundary detection.

10.1038/s41467-023-36188-7NATURE COMMUNICATIONS14

Federated Learning Enables Big Data for Rare Cancer Boundary Detection

Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing

Predictors of Long-Term Survival in Patients With Glioblastoma Multiforme: Advancements From the Last Quarter Century

Over the last quarter century there has been significant progress toward identifying certain characteristics and patterns in GBM patients to predict survival times and outcomes. We sought to identify clinical predictors of survival in GBM patients from the past 24 years. We examined patient survival related to tumor locations, surgical treatment, postoperative course, radiotherapy, chemotherapy, patient age, GBM recurrence, imaging characteristics, serum, and molecular markers. We present predictors that may increase, decrease, or play no significant role in determining a GBM patient's long-term survival or affect the quality of life

The management of incidental low-grade gliomas using magnetic resonance imaging: systematic review and optimal treatment paradigm

Object The discovery of incidental low-grade gliomas (LGGs) on MR imaging is rare, and currently there is no existing protocol for management of these lesions. Various studies have approached the dilemma of managing patients with incidental LGGs. While some advocate surgery and radiotherapy, others reserve surgery until there is radiological evidence of growth. For neurosurgeons and radiologists, determining the course of action after routine brain imaging poses not only a medical but also an ethical dilemma. The authors conducted a systematic review of case reports and case series in hopes of enhancing the current understanding of the management options for these rare lesions. Methods A PubMed search was performed to include all relevant MR imaging studies in which management of suspected incidental LGG was reported. Comparisons were made between the surgical treatment arm and the active surveillance arm in terms of outcome, mode of discovery, reasons for treatment, and histology. Results Nine studies with 72 patients were included in this study (56 in the surgical arm and 16 in the active surveillance arm). Within the surgical arm, 49% remained deficit free after treatment, 25% showed evidence of tumor progression, 13% underwent a second treatment, and 7% died. The active surveillance group resulted in no unanticipated adverse events, with serial imaging revealing no tumor growth in all cases. Lesion regression was reported in 31% of this group. The surgical arm's mortality rate was 7% compared with 0% in the active surveillance arm. Conclusions Treatment decisions for incidental LGG should be individualized based on presenting symptoms and radiological evidence of growth. The asymptomatic patient may be monitored safely with serial MR imaging and occasionally PET scanning before treatment is initiated. In patients presenting with nonspecific symptoms or concurrent symptomatic lesions, treatment may be initiated earlier to reduce potential morbidity. All treatment decisions must be tempered by patient factors and expectations of anticipated benefit

A novel technique for stabilization of high-grade spondylolisthesis with transvertebral fusion without reduction

•One-stage technique manages local malalignment with a technique that minimizes risk.•Bilateral threaded pedicle screws of large diameter and length instead of a single fibula allograft.•Placing pedicle screws with a transvertebral trajectory through the two end plates.•Report on 3 patients- no CSF leaks, intragenic insults, implant failures, or revisions.•The minimal complications and favorable outcomes make this technique an effective, efficient and safe procedure. Surgical treatment of high-grade spondylolisthesis and spondyloptosis is recommended in symptomatic patients, yet there exists much debate regarding the optimal surgical approach and the need for reduction. Similar to the Bohlman technique in that fixation is achieved across two vertebral endplates, we discuss a novel technique with the advantage of using bilateral threaded pedicle screws of large diameter and length instead of a single fibula allograft. Patients underwent posterior instrumented fusion without spondylolisthesis reduction using a novel technique placing pedicle screws with a transvertebral trajectory through the two end plates involved in the spondylolisthesis. Following screw placement, patients underwent decompression ± discectomy. Screws were connected to adjacent pedicle screws either in the upper adjacent vertebrae (i.e. L5) or the more rostral adjacent vertebrae (i.e. L4) if spinal alignment or instability necessitate including additional levels of fixation. Three patients were reviewed with ages of 67, 62, 58 years, operative times of 377–790 min, estimated blood loss 400–1050 cc, and follow-up times of 478–1082 days. There were no CSF leaks, intragenic neurologic deficits post-operatively, implant failures, revisions, or other systemic events. Two patients achieve radiographic fusion assessed by CT. At the time of final follow up, all patients were satisfied and essentially pain free. This one-stage technique offers the ability to manage local malalignment with a technique that inherently minimizes risk. The minimal complications and favorable outcomes make this technique an effective, efficient and safe procedure. Additional studies will focus on long term outcomes and should include larger patient samples

Prophylactic vertebral cement augmentation at the uppermost instrumented vertebra and rostral adjacent vertebra for the prevention of proximal junctional kyphosis and failure following long-segment fusion for adult spinal deformity

Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are common problems after long-segment (>5 levels) thoracolumbar instrumented fusions in the treatment of adult spinal deformity (ASD). No specific surgical strategy has definitively been shown to lower the risk of PJK as the result of a multifactorial etiology. The study aimed to assess the incidence of PJK and PJF in patients treated with prophylactic polymethylmethacrylate (PMMA) cement augmentation at the uppermost instrumented vertebrae (UIV) and rostral adjacent vertebrae (UIV+1). This is a retrospective cohort-matched surgical case series at an academic institutional setting. Eighty-five adult patients over a 16-year enrollment period were identified with long-segment (>5 levels) posterior thoracolumbar instrumented fusions for ASD. Primary outcomes measures were PJK magnitude and PJF formation. Secondary outcomes measures were spinopelvic parameters, as well as global and regional sagittal alignment. The impact of adjunctive PMMA use in long-segment (≥5 levels) fusion for ASD was assessed in adult patients aged 18 and older. Patients were included with at least one of the following: lumbar scoliosis >20°, pelvic tilt >25°, sagittal vertical axis >5 cm, central sacral vertical line >2 cm, and thoracic kyphosis >60°. The frequency of PJF and the magnitude of PJK were measured radiographically preoperatively, postoperatively, and at maximum follow-up in controls (Group A) and PMMA at the UIV and UIV+1 (Group B). Eighty-five patients (64±11.1 years) with ASD were identified: 47 control patients (58±10.6) and 38 patients (71±6.8) treated with PMMA at the UIV and UIV+1. The mean follow-up was 27.9 and 24.2 months in Groups A and B, respectively (p=.10). Preoperative radiographic parameters were not significantly different, except the pelvic tilt which was greater in Group A (26.6° vs. 31.4°, p=.03). Postoperatively, the lumbopelvic mismatch was greater in Group B (14.6° vs. 7.9°, p=.037), whereas the magnitude of PJK was greater in controls (9.36° vs. 5.65°, p=.023). The incidence of PJK was 36% (n=17) and 23.7% (n=9) in Groups A and B, respectively (p=.020). The odds ratio of PJK with vertebroplasty was 0.548 (95% confidence interval=0.211 to 1.424). Proximal junctional kyphosis was observed in 6 (12.8%) controls only (p=.031). The UIV+1 angle, a measure of PJK, was significantly greater in controls (10.0° vs. 6.8°, p=.02). No difference in blood loss was observed. No complications were attributed to PMMA use. The use of prophylactic vertebral cement augmentation at the UIV and rostral adjacent vertebral segment at the time of deformity correction appears to be preventative in the development of proximal junctional kyphosis and failure

Effects of menopausal state on lumbar decompression and fusion surgery

•Menopausal metabolic changes may predispose to fusion related complications.•Postmenopausal patients have higher rates of pseudarthrosis and PJK.•The need for revision surgery is not higher in postmenopausal patients. Menopause leads to fluctuations in androgenic hormones which directly affect bone metabolism. Bone resorption, mineralization, and remodeling at fusion sites are essential in order to obtain a solid and biomechanically stable fusion mass. Bone metabolic imbalance seen in the postmenopausal state may predispose to fusion related complications. The aim of this study was to investigate fusion outcomes in lumbar spinal fusion surgery in women based on menopausal status. A retrospective analysis of all female patients who underwent posterior lumbar decompression and fusion at a single institution from 2013 to 2017 was performed. A total of 112 patients were identified and stratified into premenopausal (n = 25) and postmenopausal (n = 87) groups. Clinical and radiographic data was assessed at 1 year follow up. Postmenopausal patients had a higher rates of pseudarthrosis (11.63% vs 0%, p = 0.08), PJK (15.1% vs 4%, p = 0.14), and revision surgery (3.5% vs 0%, p = 0.35). The number of levels fused was associated with increased risk of pseudarthrosis (OR 1.4, p = 0.02); however, there was no association between age, hormonal use, prior tobacco use, or T-score. Age was associated with increased risk of developing PJK (OR = 1.11, p = 0.01); however, PJK was not associated with menopause, hormonal use, prior tobacco use, or T-score. Revision surgery was not associated with age, hormonal use, prior tobacco use, or T-score. This study suggests that postmenopausal women may be prone to have higher rates of pseudarthrosis, PJK and revision surgery, although our results were not statistically significant. Larger studies with longer follow up will help elucidate the true effects of menopause in spine surgery

A review of stereotactic radiosurgery practice in the management of skull base meningiomas

Gross total resection of skull base meningiomas poses a surgical challenge due to their proximity to neurovascular structures. Once the gold standard therapy for skull base meningiomas, microsurgery has been gradually replaced by or used in combination with stereotactic radiosurgery (SRS). This review surveys the safety and efficacy of SRS in the treatment of cranial base meningiomas including 36 articles from 1991 to 2010. SRS produces excellent tumor control with low morbidity rates compared with surgery alone for asymptomatic small skull base meningiomas, patients with risk factors precluding conventional surgery, and as adjuvant therapy for recurrent or residual lesions