Letter to the Editor. Delayed parent vessel occlusion in Pipeline embolization
Visish M. Srinivasan and Peter Kan
Updates on recent landmark thrombectomy trials
Marco Colasurdo and Peter Kan
Minimally invasive thoracoscopic approach for anterior decompression and stabilization of metastatic spine disease
Peter Kan and Meic H. Schmidt
The choices available in the management of metastatic spine disease are complex, and the role of surgical therapy is increasing. Recent studies have indicated that patients treated with direct surgical decompression and stabilization before radiation have better functional outcomes than those treated with radiation alone. The most common anterior surgical approach for direct spinal cord decompression and stabilization in the thoracic spine is open thoracotomy; however, thoracotomy for spinal access is associated with morbidity that can be avoided with minimally invasive techniques like thoracoscopy.
A minimally invasive thoracoscopic approach was used for the surgical treatment of thoracic and thoracolumbar metastatic spinal cord compression. This technique allows ventral decompression via corpectomy, inter-body reconstruction with expandable cages, and stabilization with an anterolateral plating system designed specifically for minimally invasive implantation. This technique was performed in 5 patients with metastatic disease of the thoracic spine, including the thoracolumbar junction.
All patients had improvement in preoperative symptoms and neurological deficits. No complications occurred in this small series.
The minimally invasive thoracoscopic approach can be applied to the treatment of thoracic and thoracolumbar metastatic spine disease in an effort to reduce access morbidity. Preliminary results have indicated that adequate decompression, reconstruction, and stabilization can be achieved with this technique.
Intraarterial delivery of virotherapy for glioblastoma
Visish M. Srinivasan, Frederick F. Lang, and Peter Kan
Oncolytic viruses (OVs) have been used in the treatment of cancer, in a focused manner, since the 1990s. These OVs have become popular in the treatment of several cancers but are only now gaining interest in the treatment of glioblastoma (GBM) in recent clinical trials. In this review, the authors discuss the unique applications of intraarterial (IA) delivery of OVs, starting with concepts of OV, how they apply to IA delivery, and concluding with discussion of the current ongoing trials. Several OVs have been used in the treatment of GBM, including specifically several modified adenoviruses. IA delivery of OVs has been performed in the hepatic circulation and is now being studied in the cerebral circulation to help enhance delivery and specificity. There are some interesting synergies with immunotherapy and IA delivery of OVs. Some of the shortcomings are discussed, specifically the systemic response to OVs and feasibility of treatment. Future studies can be performed in the preclinical setting to identify the ideal candidates for translation into clinical trials, as well as the nuances of this novel delivery method.
Diffuse large B-cell lymphoma presenting as a sacral tumor
Report of two cases
James K. Liu, Peter Kan, and Meic H. Schmidt
Primary lymphomas of the sacrum are rare tumors, reported only in a few cases in the literature. The authors describe two patients with diffuse large B-cell lymphomas presenting as a sacral tumor.
In the first case a 52-year-old man presented with progressive back pain, bilateral radicular pain, and saddle block anesthesia secondary to a lytic, expansile soft-tissue mass. The mass arose from the sacrum and eroded through the right S-1 to S-4 foramina and extended into the epidural space of the spinal canal. On magnetic resonance imaging, the sacral mass enhanced homogeneously with Gd. In the second case a 64-year-old man presented with left-sided radicular pain, paresthesias, and progressive weakness due to a lytic soft-tissue mass in the left sacral ala extending into the left L-5 and S-1 foramina. Metastatic workup in each patient demonstrated unremarkable findings. In both cases, an open biopsy procedure was performed after nondiagnostic examination of needle biopsy samples. Histopathological examination showed evidence consistent with diffuse large B-cell lymphoma in both patients. In the first case the disease was classified as Stage IAE, and the patient subsequently underwent four cycles of cyclophosphamide/doxorubicin/vincristine/prednisone (CHOP)– and rituximab-based chemotherapy followed by consolidation radiotherapy. In the second case the disease was also classified as Stage IAE, and the patient underwent CHOP-based chemotherapy and consolidation radiotherapy. In both cases radiography demonstrated a decrease in size of the sacral lymphomas.
The authors review the clinical, radiological, and histological features of sacral lymphomas. Lymphoma should be considered in the differential diagnosis of sacral tumors.
Woven EndoBridge embolization in the retreatment of basilar apex aneurysm
Jae Eun Lee, Visish M. Srinivasan, and Peter Kan
The Woven EndoBridge (WEB) device was approved by the U.S. FDA for its excellent angiographic occlusion of intracranial aneurysms and high safety profile, based on the landmark WEB-IT (WEB Intrasaccular Therapy) trial. There remains, however, a few cases of aneurysm recurrence that necessitate retreatment after the initial WEB procedure. In this technical video, the authors present the case of a middle-aged patient who showed significant basilar apex aneurysm recurrence and growth along with device compaction that required retreatment. Various aspects of treating aneurysms with a prior WEB device, including procedural technique, are discussed.
The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID21152
PulseRider treatment of an anterior communicating artery aneurysm
Visish M. Srinivasan, Aditya Vedantam, and Peter Kan
We present a case of a patient with an anterior communicating artery aneurysm treated by PulseRider-assisted coil embolization. PulseRider is a new device, FDA approved for treatment of broad-necked aneurysms of the basilar apex or internal carotid artery terminus. The aneurysm was broad-necked and involved the anterior communicating artery and was considered for traditional stent-assisted coiling as well as PulseRider-assisted coiling. The authors present the treatment plan and strategy and then fluoroscopic recording of the PulseRider delivery and subsequent coiling phase. Nuances of technique for this new device used in a challenging setting are discussed.
The video can be found here: https://youtu.be/ont7ggqgLH8.
Trans-superior ophthalmic vein approach for treatment of carotid-cavernous fistula
Visish M. Srinivasan, Anish N. Sen, and Peter Kan
The authors present a case of a patient with a Barrow Type B carotid-cavernous fistula (CCF) who presented with severe symptoms of eye redness, diplopia, and proptosis. Due to the tortuosity and size of her angular vein and the lack of good flow/access via the inferior petrosal sinus, she was treated with a transvenous approach via a large, dilated superior ophthalmic vein for coil embolization of the CCF. The patient had a full angiographic and symptomatic cure. The authors present the treatment plan and strategy and the fluoroscopic recording of the treatment. Nuances of the technique are discussed.
The video can be found here: https://youtu.be/ABkGm17-cBU.
Middle meningeal artery embolization as standalone treatment versus combined with surgical evacuation for chronic subdural hematomas: systematic review and meta-analysis
Huanwen Chen, Marco Colasurdo, and Peter T. Kan
Middle meningeal artery embolization (MMAE) is a novel treatment for chronic subdural hematomas (cSDHs) with high variability of use across practitioners and institutions. This study sought to investigate whether standalone MMAE may be an effective alternative to combined MMAE and surgery for select patients with cSDH.
The authors searched the Medline and Embase databases for studies reporting outcomes specific to standalone MMAE and combined MMAE and surgery. The Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool was used to assess risk of bias in each included study. Patient characteristics were compared between cohorts, and rates of surgical recurrence of standalone MMAE and combined MMAE and surgery were pooled using random-effects models.
Four hundred two unique patients (156 with standalone MMAE and 246 with combined MMAE and surgery) were identified across 8 studies. Overall, the subdural thickness for the standalone MMAE group was modestly but statistically significantly smaller (16.8 vs 18.8 mm, estimated p value 0.002), and the mean follow-up time was significantly longer for the standalone MMAE group (5.4 vs 2.3 months, estimated p value < 0.001); there were no significant differences between age, sex, and anticoagulant use. The surgical recurrence rates were not significantly different between the two groups (estimated p value 0.63). Using random-effects models, the surgical recurrence rates were estimated at 6.8% (95% CI 3.5%–11.2%) and 4.6% (95% CI 2.3%–7.7%) for standalone MMAE and combined MMAE and surgery, respectively.
Standalone MMAE for cSDH may yield a low rate of surgical recurrence, which may be comparable to that of combined MMAE and surgery. However, studies in this systematic review and meta-analysis were primarily single-arm studies prone to treatment bias. Future studies are needed to further investigate whether standalone MMAE may be an effective alternative to combined MMAE and surgical treatment for cSDH in select patients.