Giant Pediatric Dural Arteriovenous Fistula Management Using a Combined Operative Approach in a Hybrid Neuroendovascular Surgery Suite: Technical Nuances and Review of Literature

BACKGROUND

Pediatric intracranial dural arteriovenous fistulas (dAVFs) are rare, complex entities usually presenting with macrocephaly from increased intracranial pressures at a young age. In the setting of a symptomatic intracranial dAVF that has undergone multiple endovascular treatments with subsequent recurrence or failed embolization attempts, the intracranial venous system can become inaccessible by traditional transvenous and transarterial routes. Direct puncture of the venous sinus for endovascular access after surgical exposure is a viable option.

OBJECTIVE

To describe the technical nuances and available literature for direct puncture of the venous sinus for endovascular access in a pediatric patient with dAVF.

METHODS

The clinical characteristics were reviewed and reported for a patient who underwent direct puncture of the venous sinus for endovascular access. In addition, a literature review was conducted for relevant literature pertaining to this technique and its associated indications, outcomes, and complications.

RESULTS

Only 2 other reports of direct puncture of venous sinus for endovascular access after surgical exposure were found in the literature. Our patient achieved a favorable outcome with complete dAVF obliteration.

CONCLUSION

Direct puncture of the venous sinus for endovascular access after surgical exposure for complex dAVFs that are inaccessible by transvenous or transarterial routes is a practical and safe approach to intracranial venous access that should be part of the vascular neurosurgeon's arsenal.

Subdural evacuation port system and middle meningeal artery embolization for chronic subdural hematoma: a multicenter experience

OBJECTIVE

Middle meningeal artery (MMA) embolization and the Subdural Evacuation Port System (SEPS) are minimally invasive treatment paradigms for chronic subdural hematoma (cSDH). Although SEPS offers acute decompression of local mass effect from a cSDH, MMA embolization has been shown to reduce the rate of cSDH recurrence. In combination, these procedures present a potentially safer strategy to a challenging pathology. The authors present a multi-institutional retrospective case series that assessed the safety, efficacy, and complications of SEPS and MMA embolization for cSDH.

METHODS

A retrospective review was performed of patients who underwent SEPS placement and MMA embolization for cSDH between 2018 and 2021 at three institutions.

RESULTS

One hundred patients with 136 cSDHs and a median age of 73 years underwent both SEPS placement and MMA embolization. Initial Glasgow Coma Scale scores were between 14 and 15 in 81% of patients and between 9 and 13 in 14%. The median initial midline shift (MLS) was 7 mm, with subdural hematoma (SDH) in the left hemisphere (lh) in 30% of patients, right hemisphere (rh) in 34%, and bilateral hemispheres in 36%. Follow-up was available for 86 patients: 93.4% demonstrated decreased MLS, and all patients with lhSDH and rhSDH demonstrated progressive decrease in SDH size. The overall complication rate was 4%, including 1 case of facial palsy and 3 cases of iatrogenic acute SDH. Two subjects (2%) required craniotomy for hematoma evacuation. The rate of good functional outcomes, with modified Rankin Scale (mRS) score < 2, was 89% on final follow-up and the overall mortality rate was 2%. A good mRS score on admission was associated with increased odds of functional improvement at follow-up (p < 0.001).

CONCLUSIONS

SEPS placement with MMA embolization for cSDH can be done safely and effectively reduces cSDH size with minimal perioperative morbidity.

Association of Noncontrast Computed Tomography and Perfusion Modalities With Outcomes in Patients Undergoing Late-Window Stroke Thrombectomy

IMPORTANCE

There is substantial controversy with regards to the adequacy and use of noncontrast head computed tomography (NCCT) for late-window acute ischemic stroke in selecting candidates for mechanical thrombectomy.

OBJECTIVE

To assess clinical outcomes of patients with acute ischemic stroke presenting in the late window who underwent mechanical thrombectomy stratified by NCCT admission in comparison with selection by CT perfusion (CTP) and diffusion-weighted imaging (DWI).

DESIGN, SETTING, AND PARTICIPANTS

In this multicenter retrospective cohort study, prospectively maintained Stroke Thrombectomy and Aneurysm (STAR) database was used by selecting patients within the late window of acute ischemic stroke and emergent large vessel occlusion from 2013 to 2021. Patients were selected by NCCT, CTP, and DWI. Admission Alberta Stroke Program Early CT Score (ASPECTS) as well as confounding variables were adjusted. Follow-up duration was 90 days. Data were analyzed from November 2021 to March 2022.

EXPOSURES

Selection by NCCT, CTP, or DWI.

MAIN OUTCOMES AND MEASURES

Primary outcome was functional independence (modified Rankin scale 0-2) at 90 days.

RESULTS

Among 3356 patients, 733 underwent late-window mechanical thrombectomy. The median (IQR) age was 69 (58-80) years, 392 (53.5%) were female, and 449 (65.1%) were White. A total of 419 were selected with NCCT, 280 with CTP, and 34 with DWI. Mean (IQR) admission ASPECTS were comparable among groups (NCCT, 8 [7-9]; CTP, 8 [7-9]; DWI 8, [7-9]; P = .37). There was no difference in the 90-day rate of functional independence (aOR, 1.00; 95% CI, 0.59-1.71; P = .99) after adjusting for confounders. Symptomatic intracerebral hemorrhage (NCCT, 34 [8.6%]; CTP, 37 [13.5%]; DWI, 3 [9.1%]; P = .12) and mortality (NCCT, 78 [27.4%]; CTP, 38 [21.1%]; DWI, 7 [29.2%]; P = .29) were similar among groups.

CONCLUSIONS AND RELEVANCE

In this cohort study, comparable outcomes were observed in patients in the late window irrespective of neuroimaging selection criteria. Admission NCCT scan may triage emergent large vessel occlusion in the late window.

Endovascular Management of Distal Anterior Cerebral Artery Aneurysms: A Multicenter Retrospective Review

INTRODUCTION

Distal anterior cerebral artery aneurysms (DACAA) are a rare and difficult entity to manage. Endovascular treatment has evolved for safe and durable treatment of these lesions. The objective of this study is to report the safety, efficacy, and outcomes of endovascular treatment of DACAA.

METHODS

A retrospective review of DACAA endovascularly treated at 5 different institutions was performed. Data included demographics, rupture status, radiographic features, endovascular technique, complication rates, and long-term angiographic and clinical outcomes. A primary endpoint was a good clinical outcome (modified Rankin scale 0-2). Secondary endpoints included complications and radiographic occlusion at follow-up.

RESULTS

A total of 84 patients were reviewed. The mean age was 56, and 64 (71.4%) were female. Fifty-two (61.9%) aneurysms were ruptured. A good functional outcome was achieved in 59 patients (85.5%). Sixty (71.4%) aneurysms were treated with primary coiling, and the remaining 24 were treated with flow diversion. Adequate occlusion was achieved in 41 (95.3%) aneurysms treated with coiling, and 17 (89.5%) with flow diversion. There were total 11 (13%) complications. In the flow diversion category, there were 2, both related to femoral access. In the coiling category, there were 9: 5 thromboembolic, 3 ruptures, and 1 related to femoral access.

CONCLUSION

Endovascular treatment, and in particular, flow diversion for DACAA, is safe, feasible, and associated with good long-term angiographic and clinical outcomes.

Neuroendovascular Management of Acute Ischemic Basilar Strokes: 2-Dimensional Operative Video

Basilar artery occlusions (BAOs) are devastating ischemic strokes that account for 1% of all strokes with high morbidity and mortality; however, neuroendovascular techniques such as ADAPT have recently revolutionized the clinical outcomes of these patients.1-3 Common underlying pathology in patients with BAO include intracranial atherosclerotic disease (ICAD) as well as thromboembolic origin.4 Basilar artery ICAD in a setting of acute stroke portends a poor prognosis and post-thrombectomy residual critical flow limiting stenosis treatment options, including balloon angioplasty with or without stent placement.5-7 We present a video illustration of neuroendovascular technique and challenges encountered when managing this pathology. Image at 5:42 reprinted with permission from Alawieh et al, Lessons learned over more than 500 stroke thrombectomies using ADAPT with increasing aspiration catheter size, Neurosurgery, 86(1), 2020, pp. 61-70, with permission from the Congress of Neurological Surgeons.1.

MGMT-inhibitor in combination with TGF-βRI inhibitor or CDK 4/6 inhibitor increases temozolomide sensitivity in temozolomide-resistant glioblastoma cells

BACKGROUND

Glioblastoma (GB) remains an incurable and deadly brain malignancy that often proves resistant to upfront treatment with temozolomide. Nevertheless, temozolomide remains the most commonly prescribed FDA-approved chemotherapy for GB. The DNA repair protein methylguanine-DNA methyl transferase (MGMT) confers resistance to temozolomide. Unsurprisingly temozolomide-resistant tumors tend to possess elevated MGMT protein levels or lack inhibitory MGMT promotor methylation. In this study, cultured human temozolomide resistance GB (43RG) cells were introduced to the MGMT inhibitor O⁶-benzylguanine combined with temozolomide and either LY2835219 (CDK 4/6 inhibitor) or LY2157299 (TGF-βRI inhibitor) seeking to overcome GB treatment resistance.

METHODS

Treatment effects were assessed using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, western blot, cell viability, and cell cycle progression.

RESULTS

Our in vitro study demonstrated that sequential treatment of O⁶-Benzylguanine with either LY2385219 or LY2157299-enhanced temozolomide enhanced sensitivity in MGMT+ 43RG cells. Importantly, normal human neurons and astrocytes remained impervious to the drug therapies under these conditions. Furthermore, LY2835219 has additional anti-proliferative effects on cell cycling, including induction of an RB-associated G (1) arrest via suppression of cyclin D-CDK4/6-Rb pathway. LY2157299 enhances anti-tumor effect by disrupting TGF-β-dependent HIF-1α signaling and by activating both Smad and PI3K-AKT pathways towards transcription of S/G2 checkpoints.

CONCLUSION

This study establishes the groundwork for the development of a combinatorial pharmacologic approach by using either LY2385219 or LY2157299 inhibitor plus O⁶-Benzylguanine to augment temozolomide response in temozolomide-resistant GB cells.

Cystic angiomatosis skull lesion obliteration with neuroendovascular sclerotherapy as a unique treatment: case report

Cystic angiomatosis is a rare bone condition with complex presentation and difficult treatment. Current management strategies have poorly tolerated side effects and a low likelihood of disease eradication. The control of calvarial lesions that are symptomatic usually involves surgical excision and subsequent cranioplasty. This paradigm can present with a risk of morbidity and mortality depending on the anatomy of the lesion. Here, the authors present a novel approach to a difficult-to-treat occipital calvarial lesion directly overlying the transverse sinus, performing a small, partial-thickness craniectomy and alcohol sclerotherapy in a combined neurosurgery-neuroendovascular approach. At 3 years after treatment, the authors noted a complete, encouraging radiographic and clinical outcome.

Evaluating anti-tumor activity of palbociclib plus radiation in anaplastic and radiation-induced meningiomas: pre-clinical investigations

PURPOSE

Meningiomas are common brain tumors, the majority of which are considered benign. Despite surgery and/or radiation therapy, recurrence rates are approximately 8-10%. One likely cause is the dysregulation of cyclin D-cyclin-dependent kinases 4 and 6 (CDK4/6)-retinoblastoma (Rb) pathway, which controls the cell cycle restriction point. This pathway is commonly dysregulated in anaplastic meningioma cell lines (AM) and radiation-induced meningioma cells (RIM), making it a rational target for anti-meningioma therapy. In this study, we investigate the effect of a CDK4/6 inhibitor, palbociclib, with radiation in relevant pre-clinical models.

METHODS

In vitro cell culture, ex vivo slice culture and in vivo cell line-derived orthotopic xenograft animal models of AM/RIM were utilized to assess treatment efficacy with palbociclib plus radiation. Treatment effects were examined by immunoblot, cell viability, apoptosis, and cell cycle progression.

RESULTS

The in vitro and ex vivo studies demonstrate that palbociclib plus radiation treatment reduced proliferation and has additional effects on cell cycling, including induction of an RB-associated G (1) arrest in Rb+ AM and RIM cells, but not in Rb- cells. Our results also demonstrated reduced CDK4 and CDK6 expression as well as reduced E2F target gene expression (CCNA2 and CCNE2) with the combination therapy. MRI results in vivo demonstrated reduced tumor size at 5 weeks when treated with 14 days palbociclib (10 mg/kg) plus 6 Gy radiation compared to saline-treated tumors. Finally, no hepatic toxicity was found after treatments.

CONCLUSION

A pre-clinical murine model provides preclinical evidence for use of palbociclib plus radiation as a therapeutic agent for Rb+ meningiomas.

Venous Thromboprophylaxis in Spine Surgery

STUDY DESIGN

Review article.

OBJECTIVE

A review of the literature on postoperative initiation of thrombophylactic agents following spine surgery.

METHODS

A review of the literature and synthesis of the data to provide an update on venous thromboprophylaxis following spine surgery.

RESULTS

Postoperative regimens of venous thromboprophylaxis measures following spine surgery remain a controversial issue. Recommendations regarding mechanical versus chemical prophylaxis vary greatly among institutions.

CONCLUSION

Postoperative spine surgery initiation of thromboprophylaxis remains controversial regarding optimal timing and agent selection. The benefits of deep vein thrombosis/pulmonary embolism prophylaxis must be weighed against the possible postoperative complications associated with spine surgery.

Anticoagulation and Spine Surgery

STUDY DESIGN

Literature review.

OBJECTIVE

Preoperative management of therapeutic anticoagulation in spine surgery is critical to minimize risk of thromboembolic events yet prevent postsurgical complications. Limited research is available, and most guidelines are based on drug half-lives. We aim to clarify current guidelines and available evidence for safe practice of spine surgery in this patient population.

METHODS

A literature search in PubMed was done encompassing comprehensive search terms to locate published literature on anticoagulation and spine surgery. Predefined inclusion and exclusion criteria were applied and data extraction was performed.

RESULTS

A total of 17 articles met the final inclusion criteria. Of these, 12 articles were retrospective chart reviews, 3 were prospective observational studies, and 2 were systematic reviews. Current practice suggests holding warfarin until international normalized ratio <1.4, anti-Xa drugs for 48 to 72 hours, 12 to 24 hours for low-molecular-weight heparin, and 4 to 24 hours for heparin, before surgery. Antiplatelet agents can be stopped for 1 to 3 days prior to operation (81-500 mg) but must be stopped for 1 week for doses >1 g/d. For Plavix, 5 to 7 days of discontinuation advised to prevent complications.

CONCLUSIONS

This review provides an overview of main anticoagulation agents seen in preoperative setting for spine patients. Although data is mixed and no true randomized control trials are available, there is growing evidence suggesting the aforementioned guidelines are needed to optimize anticoagulation in setting of spine surgery. Further studies are needed to elucidate risk of complications while operating under therapeutic levels of anticoagulation for a variety of comorbid conditions.