Transsulcal approach supported by navigation-guided neurophysiological monitoring for resection of paracentral cavernomas

Microsurgical removal of supratentorial and cerebellar cavernous malformations: what has changed? A single institution experience

BACKGROUND

Features associated with a safe surgical resection of cerebral cavernous malformations (CMs) are still not clear and what is needed to achieve this target has not been defined yet.

METHODS

Clinical presentation, radiological features and anatomical locations were assessed for patients operated on from January 2008 to January 2018 for supratentorial and cerebellar cavernomas. Supratentorial CMs were divided into 3 subgroups (non-critical vs. superficial critical vs. deep critical). The clinical outcome was assessed through modified Rankin Scale (mRS) and was divided into favorable (mRS 0-1) and unfavorable (mRS ≥ 2). Post-operative epilepsy was classified according to the Maraire Scale.

RESULTS

A total of 144 were considered eligible for the current study. At 6 months follow-up the clinical outcome was excellent for patients with cerebellar or lobar CMs in non-critical areas (mRS ≤ 1: 91.1 %) and for patients with superficial CMs in critical areas (mRS ≤ 1: 92.3 %). Patients with deep-seated suprantentorial CMs showed a favorable outcome in 76.9 %. As for epilepsy 58.5 % of patients presenting with a history of epilepsy were free from seizures and without therapy (Maraire grade I) at last follow-up (mean 3.9 years) and an additional 41.5 % had complete control of seizures with therapy (Maraire grade II).

CONCLUSIONS

Surgery is safe in the management of CMs in non-critical but also in critical supratentorial locations, with a caveat for deep structures such as the insula, the basal ganglia and the thalamus/hypothalamus.

Cortical incisions and transcortical approaches for intra-axial and intraventricular lesions: A scoping review

Background

Transcortical approaches, encompassing various surgical corridors, have been employed to treat an array of intraparenchymal or intraventricular brain pathologies, including tumors, vascular malformations, infections, intracerebral hematomas, and epileptic surgery. Designing cortical incisions relies on the lesion location and characteristics, knowledge of eloquent functional anatomy, and advanced imaging such as tractography. Despite their widespread use in neurosurgery, there is a noticeable lack of systematic studies examining their common lobe access points, associated complications, and prevalent pathologies. This scoping review assesses current evidence to guide the selection of transcortical approaches for treating a variety of intracranial pathologies.

Methods

A scoping review was conducted using the PRISMA-ScR guidelines, searching PubMed, EMBASE, Scopus, and Web of Science. Studies were included if ≥5 patients operated on using transcortical approaches, with reported data on clinical features, treatments, and outcomes. Data analysis and synthesis were performed.

Results

A total of 50 articles encompassing 2604 patients were included in the study. The most common primary pathology was brain tumors (60.6%), particularly gliomas (87.4%). The transcortical-transtemporal approach was the most frequently identified cortical approach (70.48%), and the temporal lobe was the most accessed brain lobe (55.68%). The postoperative course outcomes were reported as good (55.52%), poor (28.38%), and death (14.62%).

Conclusion

Transcortical approaches are crucial techniques for managing a wide range of intracranial lesions, with the transcortical-transtemporal approach being the most common. According to the current literature, the selective choice of cortical incision and surgical corridor based on the lesion's pathology and anatomic-functional location correlates with acceptable functional outcomes.

Anesthetic Management of Awake Craniotomy for Resection of the Language and Motor Cortex Vascular Malformations

BACKGROUND

Although the safety and feasibility of awake craniotomy are well established for epilepsy and brain tumor surgery, its application for resection of vascular lesions, including arteriovenous malformations (AVMs) and cavernomas, is still limited. Apart from the usual challenges of awake craniotomy, vascular lesions pose several additional problems. Our goal is to determine the safety and practicality of awake craniotomy in patients with cerebral vascular malformations located near the eloquent areas, using a refined anesthetic protocol.

METHODS

A retrospective case series was performed on 7 patients who underwent awake craniotomy for resection of AVMs or cavernomas located in the eloquent language and motor areas. Our protocol consisted of achieving deep sedation, without a definitive airway, using a combination of propofol, dexmedetomidine, and remifentanil/fentanyl during scalp block placement and surgical exposure, then transitioning to a wakeful state during the resection.

RESULTS

Six patients had intracranial AVMs, and 1 patient had a cavernoma. Six patients had complete resection; however, 1 patient underwent repeat awake craniotomy for residual AVM nidus. The patients tolerated the resection under continuous awake neurologic and neurophysiologic testing without significant perioperative complications or the need to convert to general anesthesia with a definitive airway.

CONCLUSIONS

Awake craniotomy for excision of intracranial vascular malformations located near the eloquent areas, in carefully selected patients, can facilitate resection by allowing close neuromonitoring and direct functional assessment. A balanced combination of sedative and analgesic medications can provide both adequate sedation and rapid wakeup, facilitating the necessary patient interaction and tolerance of the procedure.

Minimally Invasive Parafascicular Surgical Approach for the Management of a Pediatric Third Ventricular Ependymoma: Case Report and Review of Literature

BACKGROUND

Minimally invasive parafascicular surgery (MIPS) has evolved into a safe alternative to access deep-seated subcortical and intraventricular pathologies. We present a case of a port-mediated resection of a pediatric third ventricular tumor.

CASE DESCRIPTION

The patient is a 7-year-old boy who presented with worsening headache, nausea, vomiting, dizziness, unsteady gait, photophobia, and blind spots with positional changes. Magnetic resonance imaging (MRI) scan revealed a large isointense mass, with areas of hyperintensities suggestive of intratumoral hemorrhage, centered in the posterior segment of the third ventricle with extension into the aqueduct of Sylvius. The superior frontal sulcus was used as an access corridor for the port to the frontal horn of the lateral ventricle en route to the third ventricle. Intraoperative visualization was aided with a 3-dimensional exoscopic system. After cannulation, the tumor was seen within the foramen of Monro and tethered to the thalamostriate vein. The tumor was removed completely, with the exception of small residual attached to the thalamostriate vein, which was left intentionally. A flexible endoscope was placed through the port to verify the absence of residual along the superior wall of the third ventricle. Intraoperative MRI scan confirmed presence of residual, along with normal postoperative changes, including pneumocephalus. Postoperative MRI scan revealed cortical recovery along the sulcal path and resolution of ventriculomegaly.

CONCLUSIONS

The patient improved from baseline, with no remaining visual deficits, headaches, or balance issues. Pathology reported a World Health Organization grade II tanycytic ependymoma. To our knowledge, few cases have reported the utilization of port-based MIPS in pediatric patients.

Surgery of Cerebral Cavernous Angiomas With Navigational Support

OBJECTIVE

Accurate localization and removal of deep-seated cavernomas through a less invasive approach is still a challenge. The aim of this study is to compare the efficacy of neuronavigation and ultrasound in guiding surgery for resection of deep-seated cavernomas by transsulcal microsurgical approach.

METHODS

A total of 38 consecutive patients who suffered from deep-seated cavernomas underwent surgery via a transsulcal microsurgical approach in our hospital between September 2016 and March 2018. Patients were randomly divided into 2 groups (20 cases in neuronavigation group and 18 cases in ultrasound group). The clinical features, character of images, and surgical outcome were analyzed.

RESULTS

There was no significant difference between the 2 groups in diameter (16.6 ± 2.7 mm versus 19.6 ± 2.0 mm, P > 0.05) and depth (19.2 ± 2.4 mm versus 22.0 ± 4.6 mm, P > 0.05) of lesions. The ultrasound group had a similar tumor resection rate (100% versus 80%, P = 0.11) and shorter operation time (119.7 ± 4.5 minutes versus 137.3 ± 4.9 minutes, P < 0.05) than that in the neuronavigation group. There was no significant difference between in the symptomatic improvement rate, complication, postoperative hospital stay, and period of follow-up (P > 0.05). No death and recurrence appeared in both groups.

CONCLUSION

Ultrasound showed certain advantages than neuronavigation in guiding resection of deep-seated cavernomas by transsulcal microsurgical approach.

Cavernous angiomas: deconstructing a neurosurgical disease

Cavernous angioma (CA) is also known as cavernoma, cavernous hemangioma, and cerebral cavernous malformation (CCM) (National Library of Medicine Medical Subject heading unique ID D006392). In its sporadic form, CA occurs as a solitary hemorrhagic vascular lesion or as clustered lesions associated with a developmental venous anomaly. In its autosomal dominant familial form (Online Mendelian Inheritance in Man #116860), CA is caused by a heterozygous germline loss-of-function mutation in one of three genes-CCM1/KRIT1, CCM2/Malcavernin, and CCM3/PDCD10-causing multifocal lesions throughout the brain and spinal cord.In this paper, the authors review the cardinal features of CA's disease pathology and clinical radiological features. They summarize key aspects of CA's natural history and broad elements of evidence-based management guidelines, including surgery. The authors also discuss evidence of similar genetic defects in sporadic and familial lesions, consequences of CCM gene loss in different tissues at various stages of development, and implications regarding the pathobiology of CAs.The concept of CA with symptomatic hemorrhage (CASH) is presented as well as its relevance to clinical care and research in the field. Pathobiological mechanisms related to CA include inflammation and immune-mediated processes, angiogenesis and vascular permeability, microbiome driven factors, and lesional anticoagulant domains. These mechanisms have motivated the development of imaging and plasma biomarkers of relevant disease behavior and promising therapeutic targets.The spectrum of discoveries about CA and their implications endorse CA as a paradigm for deconstructing a neurosurgical disease.

Predictors of Epileptic Seizures and Ability to Work in Supratentorial Cavernous Angioma Located Within Eloquent Brain Areas

BACKGROUND

The postoperative outcomes and the predictors of seizure control are poorly studied for supratentorial cavernous angiomas (CA) within or close to the eloquent brain area.

OBJECTIVE

To assess the predictors of preoperative seizure control, postoperative seizure control, and postoperative ability to work, and the safety of the surgery.

METHODS

Multicenter international retrospective cohort analysis of adult patients benefitting from a functional-based surgical resection with intraoperative functional brain mapping for a supratentorial CA within or close to eloquent brain areas.

RESULTS

A total of 109 patients (66.1% women; mean age 38.4 ± 12.5 yr), were studied. Age >38 yr (odds ratio [OR], 7.33; 95% confidence interval [CI], 1.53-35.19; P = .013) and time to surgery > 12 mo (OR, 18.21; 95% CI, 1.11-296.55; P = .042) are independent predictors of uncontrolled seizures at the time of surgery. Focal deficit (OR, 10.25; 95% CI, 3.16-33.28; P < .001) is an independent predictor of inability to work at the time of surgery. History of epileptic seizures at the time of surgery (OR, 7.61; 95% CI, 1.67-85.42; P = .003) and partial resection of the CA and/or of the hemosiderin rim (OR, 12.02; 95% CI, 3.01-48.13; P < .001) are independent predictors of uncontrolled seizures postoperatively. Inability to work at the time of surgery (OR, 19.54; 95% CI, 1.90-425.48; P = .050), Karnofsky Performance Status ≤ 70 (OR, 51.20; 95% CI, 1.20-2175.37; P = .039), uncontrolled seizures postoperatively (OR, 105.33; 95% CI, 4.32-2566.27; P = .004), and worsening of cognitive functions postoperatively (OR, 13.71; 95% CI, 1.06-176.66; P = .045) are independent predictors of inability to work postoperatively.

CONCLUSION

The functional-based resection using intraoperative functional brain mapping allows safe resection of CA and the peripheral hemosiderin rim located within or close to eloquent brain areas.

Treatment of cavernous malformations in supratentorial eloquent areas: experience after 10 years of patient-tailored surgical protocol

BACKGROUND

Eloquent area surgery has become safer with the development of intraoperative neurophysiological monitoring and brain mapping techniques. However, the usefulness of intraoperative electric brain stimulation techniques applied to the management and surgical treatment of cavernous malformations in supratentorial eloquent areas is still not proven. With this study, we aim to describe our experience with the use of a tailored functional approach to treat cavernous malformations in supratentorial eloquent areas.

METHODS

Twenty patients harboring cavernous malformations located in supratentorial eloquent areas were surgically treated. Individualized functional approach, using intraoperative brain mapping and/or neurophysiological monitoring, was utilized in each case. Eleven patients underwent surgery under awake conditions; meanwhile, nine patients underwent asleep surgery.

RESULTS

Total resection was achieved in 19 cases (95%). In one patient, the resection was not possible due to high motor functional parenchyma surrounding the lesion tested by direct cortical stimulation. Ten (50%) patients presented transient neurological worsening. All of them achieved total neurological recovery within the first year of follow-up. Among the patients who presented seizures, 85% achieved seizure-free status during follow-up. No major complications occurred.

CONCLUSIONS

Intraoperative electric brain stimulation techniques applied by a trained multidisciplinary team provide a valuable aid for the treatment of certain cavernous malformations. Our results suggest that tailored functional approach could help surgeons in adapting surgical strategies to prevent patients' permanent neurological damage.

Awad I, Dahlem K, Flemming K, Hart B, Kim H, Jusue-Torres I, Kondziolka D, Lee C, Morrison L, Rigamonti D, Rebeiz T, Tournier-Lasserve E, Waggoner D, Whitehead K. Synopsis of Guidelines for the Clinical Management of Cerebral Cavernous Malformations: Consensus Recommendations Based on Systematic Literature Review by the Angioma Alliance Scientific Advisory Board Clinical Experts Panel

BACKGROUND

Despite many publications about cerebral cavernous malformations (CCMs), controversy remains regarding diagnostic and management strategies.

OBJECTIVE

To develop guidelines for CCM management.

METHODS

The Angioma Alliance ( www.angioma.org ), the patient support group in the United States advocating on behalf of patients and research in CCM, convened a multidisciplinary writing group comprising expert CCM clinicians to help summarize the existing literature related to the clinical care of CCM, focusing on 5 topics: (1) epidemiology and natural history, (2) genetic testing and counseling, (3) diagnostic criteria and radiology standards, (4) neurosurgical considerations, and (5) neurological considerations. The group reviewed literature, rated evidence, developed recommendations, and established consensus, controversies, and knowledge gaps according to a prespecified protocol.

RESULTS

Of 1270 publications published between January 1, 1983 and September 31, 2014, we selected 98 based on methodological criteria, and identified 38 additional recent or relevant publications. Topic authors used these publications to summarize current knowledge and arrive at 23 consensus management recommendations, which we rated by class (size of effect) and level (estimate of certainty) according to the American Heart Association/American Stroke Association criteria. No recommendation was level A (because of the absence of randomized controlled trials), 11 (48%) were level B, and 12 (52%) were level C. Recommendations were class I in 8 (35%), class II in 10 (43%), and class III in 5 (22%).

CONCLUSION

Current evidence supports recommendations for the management of CCM, but their generally low levels and classes mandate further research to better inform clinical practice and update these recommendations. The complete recommendations document, including the criteria for selecting reference citations, a more detailed justification of the respective recommendations, and a summary of controversies and knowledge gaps, was similarly peer reviewed and is available on line www.angioma.org/CCMGuidelines .

Usefulness of Preoperative Surgical Simulation with Three-Dimensional Fusion Images for Resection of Cerebral Cavernous Malformations Near Broca's Area

Treating subcortical brain lesions in or near eloquent areas is challenging not only because lesions must be resected while preserving brain tissue involved in essential functions, but also because lesions often cannot be easily identified from the surface of the brain. Here, we report 2 cases of cerebral cavernous malformations near Broca's area. In both cases, lesions were surgically removed by utilizing three-dimensional fusion images created using preoperative magnetic resonance imaging and computed tomography data. Excisions were completed without any worsening of speech function, and the use of presurgical simulations was found to be useful in the design and execution of the actual operations. The technique described in this report serves as a useful tool in simulating surgical strategies by using brain gyri and sulci as surgical landmarks. Furthermore, in contrast to other intraoperative techniques, this method can aid in shortening the duration of surgery and can help limit damage to eloquent areas of the brain.

May we use communication as an instrument? A simple neuromonitoring method peripheral nerve tumour resection

We performed a procedure called awake simple peripheral nerve monitoring of the distal lower extremity. In this procedure we aimed to protect the patient's peroneal nerve during the successful removal of a tumour arising from this nerve. This is the first report that explores the use of communication with the patient during peripheral nerve tumour resection.

Navigated transcranial magnetic stimulation in preoperative planning for the treatment of motor area cavernous angiomas

Since the introduction of microscopic techniques, radical surgery for cavernous angiomas has become a recommended treatment option. However, the treatment of motor area cavernous angioma represents a great challenge for the surgical team. Here, we describe an approach guided by frameless neuronavigation and preoperative functional mapping with transcranial magnetic stimulation (TMS), for surgical planning. We used TMS to map the motor cortex and its relationship with the angioma. We achieved complete resection of the lesions in the surgeries, while avoiding areas of motor response identified during the preoperative mapping. We verified the complete control of seizures (Engel class 1A) in the patients with previous refractory epilepsy. Postsurgery, one patient was seizure-free without medication, and two patients required only one medication for seizure control. Thus, navigated TMS appears to be a useful tool, in preoperative planning for cavernous angiomas of the motor area.

Localization techniques in resection of deep seated cavernous angiomas - review and reevaluation of frame based stereotactic approaches

BACKGROUND

Providing high accuracy is crucial in neurosurgery especially for resection of deep seated small cerebral pathologies such as cavernous angiomas. The goal of the present series was to reevaluate the feasibility, accuracy, efficacy and safety of frame-based, stereotactically guided resection for patients suffering from small deep-seated cavernous angiomas. Additionally a review of the literature on navigational tools in cavernoma surgery is provided comparing different navigation strategies.

METHODS

Ten patients with deep-seated, small intracranial, cavernous angiomas being subject to frame-based, stereotactically aided resection are included in this survey. Based on the stereotactic-fused image, set entry and target point aimed at the rim of the cavernoma were calculated. A minicraniotomy (< 3 cm in diameter) was performed followed by positioning of the stereotactic needle. Following the needle in situ the cavernous angioma was localized and resected. Assets and drawbacks of the stereotactic-aided approach were evaluated, patients were analyzed for surgery-related neurological deficits and completeness of resection.

RESULTS

Complete resection was achieved in all ten patients verified by post-surgery MRI imaging. The surgical procedure itself was only slightly aggravated by the stereotactic equipment. No adverse events such as bleedings or infections were observed in our series.

CONCLUSIONS

Stereotactically guided, minimally invasive resection of deep seated and small cavernous angiomas is accurate and effective. The frame-based stereotactic guidance requires some additional time and effort which seems justified only for deep seated and small cavernous angiomas. Frameless neuronavigation is a common tool in cavernoma surgery and its spatial resolution is sufficient for the majority of cases.

Awake mapping for resection of cavernous angioma and surrounding gliosis in the left dominant hemisphere: surgical technique and functional results: clinical article

OBJECT

Maximal resection of symptomatic cavernous angioma (CA), including its surrounding gliosis if possible, has been recommended to minimize the risk of seizures or (re)bleeding. However, despite recent neurosurgical advances, such extensive CA removal is still a challenge in eloquent areas. The authors report a consecutive series of patients who underwent awake surgery for CA within the left dominant hemisphere in which intraoperative cortical-subcortical electrical stimulation was used.

METHODS

Nine patients harboring a CA that was revealed by seizures in 6 cases and bleeding in 3 cases underwent resection. All CAs were located in the left dominant hemisphere: 3 temporal, 2 insular, 2 parietal, and 2 in the parietotemporal region. Awake mapping was performed in all cases by using intraoperative cortical-subcortical electrical stimulation and ultrasonography (except in 1 insular CA in which a neuronavigation system was used).

RESULTS

Total removal of the CA was achieved in all patients, with identification and preservation of language and sensory-motor structures. In addition, the pericavernomatous gliosis was removed in 7 cases, according to the functional boundaries provided by intraoperative subcortical stimulation. In 2 cases, subcortical mapping revealed eloquent areas within the surrounding gliosis, which was voluntarily avoided. There was no postsurgical permanent deficit, no rebleeding, and no epilepsy in 7 cases (2 patients had rare seizures in the 1st year or two after surgery, and then complete arrest), with a mean follow-up of 28.5 months (range 3-64 months).

CONCLUSIONS

These results suggest that intraoperative cortical-subcortical stimulation in awake patients represents a valuable adjunct to image-guided surgery with the aim of selecting the safer surgical approach for CAs involving eloquent areas. Moreover, such online mapping can be helpful when removing the pericavernomatous gliosis while preserving functional structures, which can persist within the hemosiderin rim. Thus, the authors propose that awake surgery be routinely considered, both to optimize the resection and to improve the quality of life through seizure control and avoidance of (re)bleeding for CAs located in the left dominant hemisphere.

Stand-alone 3D-ultrasound navigation after failure of conventional image guidance for deep-seated lesions

Image guidance has proven to be an important tool in surgery for deep-seated or eloquently located cavernomas. However, neuronavigation depending on preoperative images can fail. Thus, the displayed anatomy might be distorted already during the approach. This report demonstrates the use of three-dimensional intraoperative ultrasound (3D-US) as a rescue tool, when conventional navigation is erroneous. Two patients with symptomatic cavernomas, the one located subcortically in the right peritrigonum, the other in the left thalamus, were operated in our clinic via an image-guided approach. An integrated ultrasound-navigation system was used for neuronavigation. In both cases, navigation based on preoperative MRI failed after the craniotomy because patient-to-image registration was lost. In both cases, a simple registration of the patient's orientation was performed. Then a 3D-US volume was acquired and navigation was performed using the 3D-US data set. This is accurate as image acquisition and navigation are done in the same system. The cavernoma was visualized without difficulties in both cases. It could be reached directly via the ultrasound-guided approach. Patients' symptoms improved postoperatively and a complete resection could be documented. Two cavernomas were successfully resected using 3D-US guidance. In our experience, stand-alone 3D-US navigation is an effective option if conventional MRI-based navigation fails.

Emerging clinical imaging techniques for cerebral cavernous malformations: a systematic review

Cerebral cavernous malformations (CCMs) are divided into sporadic and familial forms. For clinical imaging, T2-weighted gradient-echo sequences have been shown to be more sensitive than conventional sequences. Recently more advanced imaging techniques such as high-field and susceptibility-weighted MR imaging have been employed for the evaluation of CCMs. Furthermore, diffusion tensor imaging and functional MR imaging have been applied to the preoperative and intraoperative management of these lesions. In this paper, the authors attempt to provide a concise review of the emerging imaging methods used in the clinical diagnosis and treatment of CCMs.

Supratentorial cavernous malformations in eloquent and deep locations: surgical approaches and outcomes. Clinical article

OBJECT

Resection of cavernous malformations (CMs) located in functionally eloquent areas of the supratentorial compartment is controversial. Hemorrhage from untreated lesions can result in devastating neurological injury, but surgery has potentially serious risks. We hypothesized that an organized system of approaches can guide operative planning and lead to acceptable neurological outcomes in surgical patients.

METHODS

The authors reviewed the presentation, surgery, and outcomes of 79 consecutive patients who underwent microresection of supratentorial CMs in eloquent and deep brain regions (basal ganglia [in 27 patients], sensorimotor cortex [in 23], language cortex [in 3], thalamus [in 6], visual cortex [in 10], and corpus callosum [in 10]). A total of 13 different microsurgical approaches were organized into 4 groups: superficial, lateral transsylvian, medial interhemispheric, and posterior approaches.

RESULTS

The majority of patients (93.7%) were symptomatic. Hemorrhage with resulting focal neurological deficit was the most common presentation in 53 patients (67%). Complete resection, as determined by postoperative MR imaging, was achieved in 76 patients (96.2%). Overall, the functional neurological status of patients improved after microsurgical dissection at the time of discharge from the hospital and at follow-up. At 6 months, 64 patients (81.0%) were improved relative to their preoperative condition and 14 patients (17.7%) were unchanged. Good outcomes (modified Rankin Scale score ≤ 2, living independently) were achieved in 77 patients (97.4%). Multivariate analysis of demographic and surgical factors revealed that preoperative functional status was the only predictor of postoperative modified Rankin Scale score (OR 4.6, p = 0.001). Six patients (7.6%) had transient worsening of neurological examination after surgery, and 1 patient (1.3%) was permanently worse. There was no surgical mortality.

CONCLUSIONS

The authors present a system of 13 microsurgical approaches to 6 location targets with 4 general trajectories to facilitate safe access to supratentorial CMs in eloquent brain regions. Favorable neurological outcomes following microsurgical resection justify an aggressive surgical attitude toward these lesions.