Sorenson, Thomas J.

Abstract Giant intracranial aneurysms still represent a serious threat because of high mortality and morbidity and an absence of a widely accepted treatment. Herein, we illustrate the case of a 54-yr-old woman with progressive neurological decline who was found to have an unruptured, giant, partially thrombosed aneurysm of the left supraclinoid portion of internal carotid artery (ICA) with brainstem compression. In this video, we demonstrate the successful stepwise treatment of this lesion with endovascular embolization of the patent portion of the aneurysm, followed by microsurgical debulking and clipping. At 3-yr follow-up, the patient experienced a neurological improvement and performed all normal activity. For patients in which single-modality therapy does not assure a safe treatment option, multimodal management with endovascular and open techniques should be considered as a therapeutic option for complex giant intracranial aneurysms. Consent was given by the patient prior to the surgical procedure. Consent and approval for this operative video, in light of the retrospective nature and use of anonymized material, were waived.

Abstract This is a case of a 73 yr-old female presenting with low back pain and bilateral sciatic pain, which progressed to bilateral lower extremity weakness about 1 yr after initial presentation. Imaging of her thoraco-lumbar spine revealed a ventriculus terminalis extending from the level of the eleventh thoracic vertebra (T11) to the first lumbar vertebra (L1). Ventriculus terminalis is an embryological ependymal lined cavity that normally regresses with development. In individuals with persistent ventriculus terminalis, it is usually incidentally noted during spine imaging for other purposes. Surgery is seldom indicated except for patients presenting with progressive neurological deficits. Patient was taken to surgery for fenestration of the ventriculus and decompression of the spinal canal. The patient was positioned prone, and after proper localization the vertebral column was exposed through a midline approach and a central laminectomy was performed from T11-L1. Intraoperative monitoring was used throughout the procedure. This video illustrates the gross appearance of a ventriculus terminalis, dissection of surrounding neural elements, and decompression of the ventriculus using a wide fenestration technique. All relevant patient identifiers have been removed from the video. Nevertheless, patient consent was obtained regarding video recording and redistribution of procedure for educational purposes.

Cavernous malformations in the midbrain can be accessed via several safe entry zones. The accepted rule of thumb is to enter at the point where the lesion is visible at the surface of the brainstem to pass through as little normal brain tissue as possible. However, in some cases, in order to avoid critical neural structures, this rule may not apply. A different safe entry zone can be chosen. Our video presents a case of a ruptured cavernous malformation in the midbrain reaching its anterior surface which was successfully resected via a posterolateral route using the supracerebellar infratentorial approach. The video can be found here: https://youtu.be/j7VTqRO7qd4 .

Cavernous malformations (CMs) are low-pressure, focal, vascular lesions that may occur within the brainstem and require treatment, which can be a substantial challenge. Herein, we demonstrate the surgical resection of a hemorrhaged brainstem CM through a posterior petrosectomy approach. After dissection of the overlying vascular and meningeal structures, a safe entry zone into the brainstem is identified based on local anatomy and intraoperative neuronavigation. Small ultrasound probes can also be useful for obtaining real-time intraoperative feedback. The CM is internally debulked and resected in a piecemeal fashion through an opening smaller than the CM itself. As brainstem CMs are challenging lesions, knowledge of several surgical nuances and adoption of careful microsurgical techniques are requisite for success. The video can be found here: https://youtu.be/szB6YpzkuCo .

Abstract Fusiform aneurysms involving the M2 branches of the middle cerebral artery are often dissecting, identified by a characteristic diseased adjacent segment, and location not at a branch point. Herein, we present the case of a 38-yr-old man with a symptomatic, dissecting M2 aneurysm that was previously incompletely treated with stent-assisted coiling. In our experience, symptomatic fusiform aneurysms in this location tend to recur unless the involved segment is completely trapped or reconstructed with flow diversion. We successfully treated this patient with a vessel reconstruction using a Pipeline Flex Embolization Device (Medtronic). Deployment of a flow diverter inside a previously placed stent can pose potential challenges, as the original stent may constrain complete expansion of the flow diverter and prevent perfect apposition against the parent vessel wall. In this operative video, we demonstrate this technique and provide a brief discussion of the potential pitfalls.

Abstract Spinal cord meningiomas are rare, benign lesions typically found at the cervical or thoracic spinal region. They can cause symptoms through compression of the spinal cord and nerve roots. These tumors often have a challenging surgical course due to their location in relation to spinal cord and nerve rootlets. We present a 33-yr-old female who presented with cervical radicular and myelopathy symptoms. MRI of the cervical spinal demonstrated an anterolateral, 3 cm intradural, extrameduallary tumor causing significant cord compression at C6-7 level. The patient was taken to surgery for cervical laminoplasty and microsurgical tumor removal. The current 3-dimensional video demonstrates the steps involved during the microsurgical resection of the tumor. In order to facilitate spinal cord rotation without compromising blood supply the dentate ligaments at 3 levels (C5-C7) were identified and transected, the anterolateral-situated tumor was separated from the exiting right C6 and C7 nerve rootlet followed by circumferential dissection, and subsequent en bloc resection. No complications were encountered during the procedure; somatosensory and motor evoked potential registration remained intact. The patient recovered well from the procedure and was discharged on postoperative day three with improvement in her presenting symptoms.

Abstract Colloid cysts are typically slow-growing lesions that account for approximately 1% of primary intracranial neoplasms and predominantly exist intraventricularly. These benign lesions typically can exist symptom-free for years and do not require surgical intervention. However, if the location of the colloid cyst is symptomatic, surgical debulking may be indicated. In this intraoperative video, we illustrate the case of an 8 cm, intra/extra-ventricular colloid cyst that appeared as a craniopharyngioma on preoperative imaging, but upon resection via a trans-middle temporal gyrus approach, was found to be very atypically filled with a thick, “tarry” substance, which we hypothesize is due to serial, subacute lesional hemorrhages. After debulking and piecemeal resection of the majority of the mass with ultrasonic aspiration and microsurgical tools, a hard, calcified nodule was left tenaciously adherent to the superior cerebellar artery to prevent damage to this vascular structure.

Craniocervical junction dural arteriovenous fistulas (dAVFs) are rare vascular lesions with a potentially dangerous natural history due to the onset of neurological deficit secondary to intracranial hemorrhage or myelopathy due to venous congestion. Despite advances in endovascular techniques, many dAVFs located in this area continue to require surgical treatment as embolization is often not feasible or safe. In this video, the authors illustrate a patient with a symptomatic craniocervical junction dAVF who had undergone attempted Onyx embolization at another institution. Because of persistent filling of the fistula and worsening myelopathy after the previous attempt, the patient was referred to the authors’ clinic for definitive surgical treatment. The video illustrates the typical location of the early draining vein in most craniocervical junction dAVFs immediately below the emergence of the vertebral artery from the dura. The patient underwent successful definitive clip ligation of the fistula, which was exposed through a lateral suboccipital craniotomy. The video can be found here: https://youtu.be/Bvg6VKLgwO0 .