Developmental Venous Anomalies

Developmental venous anomalies (DVAs) are the most common vascular malformation detected on intracranial cross-sectional imaging. They are generally benign lesions thought to drain normal parenchyma. Spontaneous hemorrhages attributed to DVAs are rare and should be ascribed to associated cerebral cavernous malformations, flow-related shunts, or venous outflow obstruction. Contrast-enhanced MRI, susceptibility-weighted imaging, and high-field MRI are ideal tools for visualizing vessel connectivity and associated lesions. DVAs are not generally considered targets for treatment. Preservation of DVAs is an established practice in the microsurgical or radiosurgical treatment of associated lesions.

Giant cavernous malformation of the posterior fossa with lymphangiomatous phenotype, associated with orbital venolymphatic anomaly in an 11-month-old patient: case report and literature review

The synchronous presentation of venolymphatic anomalies of the orbit and noncontiguous intracranial cavernous malformations is uncommon. Herein, we present a case of an 11-month-old female patient diagnosed with orbital venolymphatic anomaly associated with a large cavernous malformation in the posterior fossa, who underwent complete surgical resection of the latter. The immunohistochemical analysis was positive for podoplanin, a marker expressed by lymphatic endothelial cells, but not vascular endothelium. This exceptional finding suggests lymphatic involvement in the etiology of the lesion. In our review of the literature, we did not find similar cases in patients under 1 year of age.

Efficacy and safety of the endoscopic "wet-field" technique for removal of supratentorial cavernous malformations

OBJECTIVE

Cerebral cavernous malformations (CMs) presenting with focal neurological symptoms or mass effects require surgical removal. In recent years, cylindrical retractors have been widely utilized for the removal of deep-seated lesions during both microscopic and endoscopic surgery. In the present study, we evaluated the efficacy and safety of endoscopic transcylinder removal of CMs using a novel wet-field technique.

METHODS

We included 13 patients with supratentorial CMs who had undergone endoscopic transcylinder surgery between April 2013 and March 2022. One patient experienced recurrence of the CM and underwent a second endoscopic transcylinder surgery. Therefore, we retrospectively evaluated 14 procedures. The surgical field was continuously irrigated with artificial cerebrospinal fluid to maintain expansion and visualization of the tumor bed. We termed this method as the "wet-field technique." Patient characteristics, symptoms, and pre- and postoperative magnetic resonance imaging results were obtained from medical records.

RESULTS

The average maximum CM diameter was 35.3 mm (range: 10-65 mm). Cylinder diameters were 6 mm in eight procedures, 10 mm in four procedures, and 17 mm in one procedure. Wet-field technique was applied in all cases. The endoscope provided a bright field of view even under water. Continuous water irrigation made it easier to observe the entire tumor bed which naturally expanded by water pressure. Gross total resection was achieved in 13 procedures, while subtotal resection was achieved in one procedure. No surgical complications were observed.

CONCLUSIONS

The endoscopic transcylinder removal using wet-field technique is safe and effective for the removal of symptomatic intracranial supratentorial CMs.

Clinical application of diffusion tensor imaging and fiber tractography in the management of brainstem cavernous malformations: a systematic review

This study aimed to systematically review the literature to determine the clinical utility and perspectives of diffusion tensor imaging (DTI) in the management of patients with brainstem cavernous malformations (BSCMs). PubMed, Embase, and Cochrane were searched for English-language articles published until May 10, 2021. Clinical studies and case series describing DTI-based evaluation of patients with BSCMs were included. Fourteen articles were included. Preoperative DTI enabled to adjust the surgical approach and choose a brainstem safe entry zone in deep-seated BSCMs. Preoperatively lower fractional anisotropy (FA) of the corticospinal tract (CST) correlated with the severity of CST injury and motor deficits. Postoperatively increased FA and decreased apparent diffusion coefficient (ADC) corresponded with the normalization of the perilesional CST, indicating motor improvement. The positive (PPV) and negative predictive value (NPV) of qualitative DTI ranged from 20 to 75% and from 66.6 to 100%, respectively. The presence of preoperative and postoperative motor deficits was associated with a higher preoperative resting motor threshold (RMT) and lower FA. A higher preoperative CST score was indicative of a lower preoperative and follow-up Medical Research Council (MRC) grade. DTI facilitated the determination of a surgical trajectory with minimized risk of WMTs' damage. Preoperative FA and RMT might indicate the severity of preoperative and postoperative motor deficits. Preoperative CST score can reliably reflect patients' preoperative and follow-up motor status. Due to high NPV, normal CST morphology might predict intact neurological outcomes. Contrarily, sparse and relatively low PPV limits the reliable prediction of neurological deficits.

Asymptomatic Familial Multiple Cerebral Cavernous Malformation in a 73-Year-Old Woman

Cerebral cavernous malformations (CCMs) are dilated blood vessels which can develop sporadically or in familial form and are the commonest malformations of blood vessels in the spinal cord and brain. The familial form is an autosomal dominant gene mutation disorder. This condition can be diagnosed with magnetic resonance imaging (MRI) and computed tomography (CT) scan, but the modality of choice is MRI because of its high sensitivity. We report a case of a 73-year-old woman with an asymptomatic multiple familial cerebral cavernous malformation (FCCM) which was previously misdiagnosed as multiple cerebral metastases on CT scan. A brain MRI performed correctly diagnosed her condition as FCCM based on the typical MRI appearances. In order not to misdiagnose brain lesions like CCM on CT scan, for cerebral metastases in resource-poor settings, radiologists must recommend advanced imaging modalities like MRI for further evaluation, thereby avoiding unnecessary invasive surgical biopsies.

Utility of a Quantitative Approach Using Diffusion Tensor Imaging for Prognostication Regarding Motor and Functional Outcomes in Patients With Surgically Resected Deep Intracranial Cavernous Malformations

BACKGROUND

Resection of deep intracranial cavernous malformations (CMs) is associated with a higher risk of neurological deterioration and uncertainty regarding clinical outcomes.

OBJECTIVE

To examine diffusion tractography imaging (DTI) data evaluating the corticospinal tract (CST) in relation to motor and functional outcomes in patients with surgically resected deep CMs.

METHODS

Perilesional CST was characterized as disrupted, displaced, or normal. Mean fractional anisotropy (FA) values were obtained for whole ipsilateral CST and in 3 regions: subcortical (proximal), perilesional, and distally. Mean FA values in anatomically equivalent regions in the contralateral CST were obtained. Clinical and radiological data were collected independently. Multivariable regression analysis was used for statistical analysis.

RESULTS

A total of 18 patients [brainstem (15) and thalamus/basal ganglia (3); median follow-up: 270 d] were identified over 2 yr. The CST was identified preoperatively as disrupted (6), displaced (8), and normal (4). Five of 6 patients with disruption had weakness. Higher preoperative mean FA values for distal ipsilateral CST segment were associated with better preoperative lower (P < .001), upper limb (P = .004), postoperative lower (P = .005), and upper limb (P < .001) motor examination. Preoperative mean FA values for distal ipsilateral CST segment (P = .001) and contralateral perilesional CST segment (P < .001) were negatively associated with postoperative modified Rankin scale scores.

CONCLUSION

Lower preoperative mean FA values for overall and defined CST segments corresponded to worse patient pre- and postoperative motor examination and/or functional status. FA value for the distal ipsilateral CST segment has prognostic potential with respect to clinical outcomes.

Endoscopic management of a cavernous malformation on the floor of third ventricle and aqueduct of Sylvius: Technical case report and review of the literature

Background:

Intraventricular cavernous malformations are unusual intracranial vascular malformations; their deep anatomical location complicates their surgical management. Microsurgical approaches are the gold standard approaches for the resection of ventricular lesions, however, they imply considerable neurovascular risks.

Case Description:

A 51-year-old patient presented with acute headache, diplopia, vertigo, blurred vision, and a depressed level of consciousness. A ventricular hemorrhage was treated with a ventriculostomy and the patient was discharged without hydrocephalus. After 11 days, he developed ataxia, diplopia, and a depressed level of consciousness. The patient was diagnosed with hydrocephalus secondary to the previous third ventricle hemorrhage. An endoscopic exploration using a 30° rigid ventricular endoscope was performed; after the third ventriculostomy, an intraventricular cavernous malformation located on the floor of the third ventricle and the aqueduct of Sylvius was resected.

Conclusions:

Three days after the surgery, magnetic resonance imaging demonstrated a gross total resection and adequate third ventriculostomy flow. One year after the surgery, the patient was asymptomatic. Neuroendoscopy has evolved towards minimally invasiveness, and in selected cases is an equally effective surgical approach to ventricular lesions. It provides minimal cerebral cortex disruption and vascular manipulation.

Supratentorial cavernous malformations

Supratentorial cavernous malformations are uncommon cerebral vascular lesions that may present many unique challenges for treating physicians. The vast majority will be discovered during workup for seizures or after symptomatic intracerebral hemorrhage. Supratentorial cavernous malformations are increasingly being discovered incidentally in patients who obtain brain imaging for unrelated reasons. Management strategies including watchful waiting, antiepileptic drug therapy, microsurgery, or an expanding array of "minimally invasive" therapies. Thus, clinical decision making is not always straightforward and a nuanced approach tempered by experience and good judgment is critical to achieving excellent clinical results.

Longitudinal evaluation of corticospinal tract in patients with resected brainstem cavernous malformations using high-definition fiber tractography and diffusion connectometry analysis: preliminary experience

OBJECT

Brainstem cavernous malformations (CMs) are challenging due to a higher symptomatic hemorrhage rate and potential morbidity associated with their resection. The authors aimed to preoperatively define the relationship of CMs to the perilesional corticospinal tracts (CSTs) by obtaining qualitative and quantitative data using high-definition fiber tractography. These data were examined postoperatively by using longitudinal scans and in relation to patients' symptomatology. The extent of involvement of the CST was further evaluated longitudinally using the automated "diffusion connectometry" analysis.

METHODS

Fiber tractography was performed with DSI Studio using a quantitative anisotropy (QA)-based generalized deterministic tracking algorithm. Qualitatively, CST was classified as being "disrupted" and/or "displaced." Quantitative analysis involved obtaining mean QA values for the CST and its perilesional and nonperilesional segments. The contralateral CST was used for comparison. Diffusion connectometry analysis included comparison of patients' data with a template from 90 normal subjects.

RESULTS

Three patients (mean age 22 years) with symptomatic pontomesencephalic hemorrhagic CMs and varying degrees of hemiparesis were identified. The mean follow-up period was 37.3 months. Qualitatively, CST was partially disrupted and displaced in all. Direction of the displacement was different in each case and progressively improved corresponding with the patient's neurological status. No patient experienced neurological decline related to the resection. The perilesional mean QA percentage decreases supported tract disruption and decreased further over the follow-up period (Case 1, 26%-49%; Case 2, 35%-66%; and Case 3, 63%-78%). Diffusion connectometry demonstrated rostrocaudal involvement of the CST consistent with the quantitative data.

CONCLUSIONS

Hemorrhagic brainstem CMs can disrupt and displace perilesional white matter tracts with the latter occurring in unpredictable directions. This requires the use of tractography to accurately define their orientation to optimize surgical entry point, minimize morbidity, and enhance neurological outcomes. Observed anisotropy decreases in the perilesional segments are consistent with neural injury following hemorrhagic insults. A model using these values in different CST segments can be used to longitudinally monitor its craniocaudal integrity. Diffusion connectometry is a complementary approach providing longitudinal information on the rostrocaudal involvement of the CST.

Resection of a pontine cavernous malformation via an endoscopic endonasal approach: a case report

BACKGROUND AND IMPORTANCE

Cavernous malformations of the brainstem are a dilemma in terms of deciding when to operate, and they remain difficult to access surgically. We present a novel approach for the resection of a brainstem cavernous malformation.

CLINICAL PRESENTATION

A 59-year-old woman presented with a 1-month history of intermittent dysarthria, right facial weakness, and left arm and leg weakness. A magnetic resonance image revealed a 2-cm mass in the pons with blood products of differing ages, consistent with a cavernous malformation. We discussed with her the risks of surgical resection and conservative management. She decided to pursue conservative management. Two weeks later, she returned to the emergency room with diplopia and left-sided hemiplegia. Acute hemorrhage within the right pons was seen. She then chose to undergo surgical resection.

CONCLUSION

The patient underwent an endoscopic transnasal approach for resection of a pontine cavernous malformation. Image guidance was used to identify key anatomic landmarks. A gross total resection was achieved without new neurological deficits. With physical and occupational therapy, the patient developed antigravity strength in her left upper and lower extremities before discharge. At her 4-week follow-up, she was ambulating independently with the assistance of a cane. We report the successful gross total resection of a pontine cavernous malformation via an endoscopic transnasal approach. This patient had improvement in neurological symptoms after surgical resection with minimal surgical morbidity. Technologic advances in endoscopic skull base approaches have provided access to lesions of the skull base previously requiring more invasive approaches.