Jeroen R. Coppens

Minimally invasive superficial temporal artery to middle cerebral artery bypass through an enlarged bur hole: the use of computed tomography angiography neuronavigation in surgical planning

The authors describe their minimally invasive technique for performing a superficial temporal artery (STA) to middle cerebral artery (MCA) bypass, which relies on an enlarged bur hole (2-2.5 cm) rather than the standard craniotomy. They perform this procedure in a minimally invasive fashion, using CT angiography for intraoperative neuronavigation as well as for preoperative identification of the donor and recipient vessels and planning of bur hole location. They present 2 cases in which this procedure was used, including one involving a patient with multivessel occlusive disease and significant cerebrovascular hemodynamic compromise in whom they performed the procedure using only local anesthetic and propofol sedation in order to minimize the risk of hypotension associated with the use of general anesthetic agents. A comprehensive literature search revealed no previously published case of an extracranial-intracranial arterial bypass procedure performed in an awake patient. The authors have adopted the described minimally invasive method for all STA-MCA bypass procedures. The awake setting, however, is reserved for specific indications, primarily patients with severe moyamoya disease, in whom ventilator-related hypocarbia can result in intraoperative ischemia, or patients with multivessel occlusive disease and significant cerebral hemodynamic compromise, in whom general anesthesia-related hypotension can lead to intraoperative ischemia.

Management of nonmissile penetrating brain injuries: a description of three cases and review of the literature.

Nonmissile penetrating intracranial injuries are uncommon events in modern times. Most reported cases describe trajectories through the orbit, skull base foramina, or areas of thin bone such as the temporal squama. Patients who survive such injuries and come to medical attention often require foreign body removal. Critical neurovascular structures are often damaged or at risk of additional injury resulting in further neurological deterioration, life-threatening hemorrhage, or death. Delayed complications can also be significant and include traumatic pseudoaneurysms, arteriovenous fistulas, vasospasm, cerebrospinal fluid leak, and infection. Despite this, given the rarity of these lesions, there is a paucity of literature describing the management of neurovascular injury and skull base repair in this setting. The authors describe three cases of nonmissile penetrating brain injury and review the pertinent literature to describe the management strategies from a contemporary cerebrovascular and skull base surgery perspective.

Analysis of Decompressive Craniectomies with Subsequent Cranioplasties in the Presence of Collagen Matrix Dural Substitute and Polytetrafluoroethylene as an Adhesion Preventative Material

OBJECTIVE Decompressive craniectomy is an established treatment for malignant intracranial hypertension. Cranioplasty is performed once cerebral swelling has resolved. Complications include infection, postoperative fluid collections, hematoma, reoperation, and seizures. Our experience using a double layer technique during craniectomy with a collagen matrix onlay dural substitute and expanded polytetrafluoroethylene for antiadhesive properties during cranioplasty was reviewed. METHODS This is a retrospective chart review of 39 consecutive patients who underwent craniectomy with placement of collagen matrix dural onlay and expanded polytetrafluoroethylene and subsequent cranioplasty. Demographic data, size of craniectomy defect, estimated blood loss, operative time, time between operations, presence of dural tackups, and postoperative complications were analyzed. RESULTS Mean operative time was 132 minutes and estimated blood loss was 112 mL. Overall complication rate was 25.6% and no mortality was encountered. Nine patients had postoperative fluid collections measuring ≥ 10 mm in thickness and/or 5 mm of midline shift. Two patients required reoperation for these collections. Two patients developed infections requiring bone flap removal. Three patients developed seizures after cranioplasty. Five patients required shunt placement for hydrocephalus. CONCLUSIONS Our dual layer closure technique at time of decompressive craniectomy carries a similar reduction in operative time and estimated blood loss when compared with cranioplasty series with other antiadhesives present. The technique described enables easy dissection of the musculocutaneous flap from the dural plane during cranioplasty and increases the safety of the operation.

Proposed clinical internal carotid artery classification system.

Introduction: Numerical classification systems for the internal carotid artery (ICA) are available, but modifications have added confusion to the numerical systems. Furthermore, previous classifications may not be applicable uniformly to microsurgical and endoscopic procedures. The purpose of this study was to develop a clinically useful classification system. Materials and Methods: We performed cadaver dissections of the ICA in 5 heads (10 sides) and evaluated 648 internal carotid arteries with computed tomography angiography. We identified specific anatomic landmarks to define the beginning and end of each ICA segment. Results: The ICA was classified into eight segments based on the cadaver and imaging findings: (1) Cervical segment; (2) cochlear segment (ascending segment of the ICA in the temporal bone) (relation of the start of this segment to the base of the styloid process: Above, 425 sides [80%]; below, 2 sides [0.4%]; at same level, 107 sides [20%];P< 0.0001) (relation of cochlea to ICA: Posterior, 501 sides [85%]; posteromedial, 84 sides [14%];P< 0.0001); (3) petrous segment (horizontal segment of ICA in the temporal bone) starting at the crossing of the eustachian tube superolateral to the ICA turn in all 10 samples; (4) Gasserian-Clival segment (ascending segment of ICA in the cavernous sinus) starting at the petrolingual ligament (PLL) (relation to vidian canal on imaging: At same level, 360 sides [63%]; below, 154 sides [27%]; above, 53 sides [9%];P< 0.0001); in this segment, the ICA projected medially toward the clivus in 275 sides (52%) or parallel to the clivus with no deviation in 256 sides (48%;P< 0.0001); (5) sellar segment (medial loop of ICA in the cavernous sinus) starting at the takeoff of the meningeal hypophyseal trunk (ICA was medial into the sella in 271 cases [46%], lateral without touching the sella in 127 cases [23%], and abutting the sella in 182 cases [31%];P< 0.0001); (6) sphenoid segment (lateral loop of ICA within the cavernous sinus) starting at the crossing of the fourth cranial nerve on the lateral aspect of the cavernous ICA and located directly lateral to the sphenoid sinus; (7) ring segment (ICA between the 2 dural rings) starting at the crossing of the third cranial nerve on the lateral aspect of the ICA; (8) cisternal segment starting at the distal dural ring. Conclusions: The classification may be applied uniformly to all skull base surgical approaches including lateral microsurgical and ventral endoscopic approaches, obviating the need for 2 separate classification systems. The classification allows extrapolation of relevant clinical information because each named segment may indicate potential surgical risk to specific structures.

Ruptured pseudoaneurysm of the middle meningeal artery presenting with a temporal lobe hematoma and a contralateral subdural hematoma.

Background: Traumatic pseudoaneurysms of the middle meningeal artery (MMA) are rare, associated with skull fractures, and have a high mortality rate. When they rupture, MMA pseudoaneurysms frequently cause epidural hematomas and occasionally ipsilateral subdural or subarachnoid hemorrhage. Isolated intraparenchymal hemorrhage has also been reported. Case Description: A 54-year-old female who suffered a loss of consciousness resulting in a fall presented with a Glasgow Coma Scale of 7t. Imaging demonstrated a right subdural hematoma (SDH) with midline shift, left skull fracture overlying the left MMA, and left temporal lobe intraparenchymal hematoma extending to the surface. The patient underwent a right craniectomy with evacuation of the SDH, and the preoperative computed tomographic angiography revealed abnormal dilation of the left MMA consistent with a pseudoaneurysm. The pseudoaneurysm was treated with endovascular treatment, and the intraparenchymal hematoma was treated conservatively. Her recovery was uneventful, and she received a cranioplasty 3 months after the decompression. Conclusions: The presence of a fracture over the MMA and intraparenchymal hematoma should prompt suspicion for a traumatic pseudoaneurysm. Pseudoaneurysms of the MMA can cause catastrophic bleeding, and prompt treatment is necessary. Endovascular embolization is an effective method that decreases the hemorrhage risk of MMA pseudoaneurysms.

The Role of Catheter Angiography in the Diagnosis of Central Nervous System Vasculitis

Background: Central nervous system vasculitis (CNSV) is a rare disorder, the pathophysiology of which is not fully understood. It involves a combination of inflammation and thrombosis. CNSV is most commonly associated with headache, gradual changes in mental status, and focal neurological symptoms. Diagnosis requires the effective use of history, laboratory testing, imaging, and biopsy. Catheter angiography can be a powerful tool in the diagnosis when common and low-frequency angiographic manifestations of CNSV are considered. We review these manifestations and their place in the diagnostic algorithm of CNSV. Summary: We reviewed the PubMed database for case series of CNSV that included 5 or more patients. Demographic and angiographic findings were collected. Angiographic findings were dichotomized between common and low-frequency findings. A system for incorporating these findings into clinical decision-making is proposed. Key Message: CNSV is a diagnostic challenge due to the absence of a true gold standard test. In the absence of such a test, catheter angiography remains a central piece of the diagnostic puzzle when appropriately employed and interpreted.

Trans-Sulcal Endoport-Assisted Evacuation of Supratentorial Intracerebral Hemorrhage: Initial Single-Institution Experience Compared to Matched Medically Managed Patients and Effect on 30-Day Mortality

BACKGROUND The surgical management of supratentorial intracerebral hemorrhages (ICH) remains controversial due to large trials failing to show clear benefits. Several minimally invasive techniques have emerged as an alternative to a conventional craniotomy with promising results. OBJECTIVE To report our experience with endoport-assisted surgery in the evacuation of supratentorial ICH and its effects on outcome compared to matched medical controls. METHODS Retrospective data were gathered of patients who underwent endoport-assisted evacuation between January 2014 and October 2016 by a single surgeon. Patients who were managed medically during the same period were matched to the surgical cohort. Previously published cohorts investigating the same technique were analyzed against the present cohort. RESULTS Sixteen patients were identified and matched to 16 patients treated medically. Location, hemorrhage volume, and initial Glasgow Coma Scale (GCS) score did not differ significantly between the 2 cohorts. The mean volume reduction in the surgical cohort was 92.05% ± 7.05%. The improvement in GCS in the surgical cohort was statistically significant (7-13, P = .006). Compared to the medical cohort, endoport-assisted surgery resulted in a statistically significant difference in in-hospital mortality (6.25% vs 75.0%, P < .001) and 30-d mortality (6.25% vs 81.25%, P < .001). Compared to previously published cohorts, the present cohort had lower median preoperative GCS (7 vs 10, P = .02), but postoperative GCS did not differ significantly (13 vs 14, P = .28). CONCLUSION Endoport-assisted surgery is associated with high clot evacuation and decreases 30-d mortality compared to a similar medical group.

Melanoma Mimicking Malignant Peripheral Nerve Sheath Tumor with Spread to the Cerebellopontine Angle: Utility of Next-Generation Sequencing in Diagnosis

Cutaneous spindle cell malignancy is associated with a broad differential diagnosis, particularly in the absence of a known primary melanocytic lesion. We present an unusually challenging patient who presented with clinical symptoms involving cranial nerves VII and VIII and a parotid-region mass, which was S100-positive while lacking in melanocytic pigment and markers. Over a year after resection of the parotid mass, both a cutaneous primary lentigo maligna melanoma and a metastatic CP angle melanoma were diagnosed in the same patient, prompting reconsideration of the diagnosis in the original parotid-region mass. Next-generation sequencing of a panel of cancer-associated genes demonstrated 19 identical, clinically significant mutations as well as a high tumor mutation burden in both the parotid-region and CP angle tumors, indicating a metastatic relationship between the two and a melanocytic identity of the parotid-region tumor.

Subcutaneous melanocytoma mimicking a lipoma: A rare presentation of a rare neoplasm with histological, immunohistochemical, cytogenetic and molecular characterization

Melanocytoma are the melanocytic tumors originating from leptomeningeal melanocytes. Melanocytomas are commonly seen in the central nervous system (CNS) and are often associated with neurocutaneous melanosis (NCM). However, simultaneous presentation of intra‐axial and extracranial melanocytoma is a very rare event. Here, we report a unique case of 21‐year‐old male with intermediate‐grade subcutaneous (SC) melanocytoma, mimicking lipoma, occurred synchronously with an intracranial melanocytoma, not associated with NCM. A 21‐year‐old Caucasian male presented to the emergency department (ED) with severe vertigo and vomiting. A magnetic resonance imaging (MRI) of the brain was performed at the ED, which revealed an SC mass in the right occipital scalp and a right cerebellopontine angle (CPA) mass. Excision of the SC mass revealed a well‐circumscribed highly pigmented melanocytic tumor. The SC mass tumor cells were positive for melanocytic lineage markers. The histopathological features were between benign melanocytomas and malignant melanomas. The Ki67 and PHH3 IHCs confirm the intermediate grade of the tumors. An array‐CGH (comparative genome hybridization) and next‐generation sequencing analysis of the tumor DNA extracted from the formalin‐fixed paraffin‐embedded tissue reveals chromosome 6p gain and p.Q209P mutation in the GNAQ gene, respectively, consistent with the diagnosis of intermediate‐grade melanocytoma.

Arteriovenous Malformations of the Brain

Arteriovenous malformations (AVM) of the brain (also known as pial or parenchymal AVMs) are defined as intracranial space-occupying lesions composed of feeding arteries, draining veins, and a nidus of tangled vessels without an intervening capillary bed. There is no normal interposed brain tissue, but there can be surrounding gliosis. Morphology can vary, but AVMs are typically triangular in shape with the base towards the cortex and the apex towards the ventricular system [Brown et al. Mayo Clin Proc 80(2):269–81, 2005; Winn. Youmans neurological surgery. 6th edn. Elsevier, Philadelphia, PA, 2011; Moftakhar et al. Neurosurg Focus 26(5):E10, 2009]. While much of the pathophysiology, epidemiology, and natural history remain unclear, there has been successful advancement in the understanding and management of these complex lesions, especially with regard to the application of microsurgical, radiosurgical, and endovascular therapies.