The surgery of cavernomas both supra-tentorial and infra-tentorial

Clinical presentation, natural history, and outcomes for infantile intracranial cavernous malformations: case series and systematic review of the literature

INTRODUCTION

Intracranial cavernous malformations (CMs) are rare vascular malformations of the central nervous system in children. Infantile patients, being a developmentally vulnerable age group, pose a special challenge for management of these lesions. We pooled data from infantile patients diagnosed at our institution and individual cases published in the literature to provide input towards therapeutic decision-making.

METHODS

A systematic search of PubMed, MEDLINE, Embase, and Scopus was performed in accordance with PRISMA guidelines to identify all reported cases of intracranial CMs in the literature for infantile patients aged ≤ 2 years. In addition, cases from our institution diagnosed between 2010 and 2020 were also included. Individual cases were pooled and analyzed for clinical presentation, natural history, and outcomes from conservative and surgical management.

RESULTS

A total of 36 cases were included, of which 32 were identified from the literature. Median age at presentation was 14 months (range: 2 days to 24 months) months; 53% (n = 19) were females. Most cavernomas (64%, 23/36) were supratentorial, while 30% (n = 11) were located in brainstem and 5.5% (n = 2) in the cerebellum. With the exception of one patient, all cases were reported to be symptomatic; seizures (n = 15/31, 48.3%) and motor deficits (n = 13/31, 42%) were the most common symptom modalities. A total of 13 patients were managed conservatively upon initial presentation. No symptomatic hemorrhages were observed during 26 total person-years of follow-up. A total of 77% (28/36) underwent surgery; either upfront (23/28, 82%) at initial presentation or following conservative management. Among 12 patients who had preoperative seizures, 11/12 (91.6%) achieved seizure freedom post-resection. Among 7 patients who presented with hemiparesis preoperatively, 5 (71%) demonstrated some improvement, while 1 remained unchanged, and another patient with a brainstem cavernous malformation had worsening of motor function postoperatively. Postoperative recurrence was noted in 3 cases (3/27, 11%).

CONCLUSION

Annual risk of repeat hemorrhage may be low for infantile patients with intracranial cavernous malformations; however, better follow-up rates and higher number of cases are needed to make a definitive assertion. Surgical resection may be associated with high rates of epilepsy cure and provide improvement in neurological function in a select number of cases.

Thalamic cavernous malformations

Cavernous malformations of the thalamus represent a particularly complex subset of cavernous malformations because of the highly eloquent nature of the involved tissue and their deep location. The decision about whether to operate on any individual lesion depends on the specific location of the lesion within the thalamus, the nature of the patient's symptoms, and the patient's history. When surgery is recommended, the approach must be chosen carefully. Each part of the thalamus is reached by a different surgical approach. These approaches include the orbitozygomatic approach to the anteroinferior thalamus, the anterior interhemispheric transcallosal approach to the medial thalamus, the anterior contralateral interhemispheric transcallosal approach to the lateral thalamus, the posterior interhemispheric transcallosal approach to the posterosuperior thalamus, the parieto-occipital transventricular approach to the lateral posteroinferior thalamus, and the suboccipital supracerebellar infratentorial/transtentorial approach to the medial posteroinferior thalamus. Careful attention to safe entry zones and image guidance can allow safe removal of these lesions when necessary.

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.

Surgical strategy for insular cavernomas

PURPOSE

Surgical treatment of cavernomas arising in the insula (especially in dominant cerebral hemisphere) is challenging in reason of the proximity to the internal capsule and lenticulostriate arteries. The advent of image guidance systems and intraoperative mapping of the subcortical language pathways has broadened the surgical indications for these lesions. In this work, we report four cases of insular cavernomas operated on, and we define a surgical strategy for these lesions.

METHODS

Between July 1997 and May 2007 in our department, four patients harboring an insular cavernoma were operated on by using image guidance system (neuronavigation in three cases, ultrasound in one case). Subcortical stimulations were used to preserve the functional language area in one case.

FINDINGS

The image guidance system determined the exact planning of the approach and determination of the ideal trajectory of insular cortex dissection. In a case of a deep left insular cavernoma, the shortest approach to remove the cavernoma was stopped in per-operative time because subcortical stimulation produced a speech inhibition, justifying another insular corticotomy. No surgical complications occurred, and the postoperative course was uneventful in all patients.

CONCLUSION

As it has been proposed by many authors, image guidance system is recommended in surgery of insular cavernomas. When the lesion is located in the dominant hemisphere, intraoperative mapping of the subcortical language pathways is also indicated to preserve the language functional areas.

CAVERNOUS MALFORMATIONS OF THE BASAL GANGLIA AND THALAMUS

CAVERNOUS MALFORMATIONS OF the basal ganglia and thalamus present a unique therapeutic challenge to the neurosurgeon given their unclear natural history, the risk of surgical treatment, and the unproven efficacy of radiosurgical therapy. Via a PubMed search of the English and French literature, we have systematically reviewed the natural history and surgical and radiosurgical management of these lesions reported through April 2008. Including rates cited for “deep” cavernous malformations, annual bleeding rates for these lesions varied from 2.8% to 4.1% in the natural history studies. Across surgical series providing postoperative or long-term outcome data on 103 patients, we found an 89% resection rate, a 10% risk of long-term surgical morbidity, and a 1.9% risk of surgical mortality. The decrease in hemorrhage risk reported 2 years after radiosurgery might be a result of natural hemorrhage clustering, underscoring the unproven efficacy of this therapeutic modality. Given the compounded risks of radiation-induced injury and post-radiosurgical rebleeding, radiosurgery at modest dosimetry (12–14 Gy marginal doses) is only an option for patients with surgically inaccessible, aggressive lesions.

[Primary brain stem hemorrhage: retrospective study of 25 cases]

INTRODUCTION

We report a retrospective series of 25 cases of brain stem hemorrhage.

METHODS

Cases of spontaneous hemorrhage of the brain stem which were observed from 1990 to 2000 in a department of neurology were reviewed. Etiological factors, CT scan at admission, clinical signs and the course of the disease were analyzed retrospectively.

RESULTS

There were 25 patients, 14 male and 11 female aged from 24 to 91. Fifteen hematomas were related to hypertension, four to coagulation disorders and two to a vascular malformation. The hemorrhage was located in the pons in 22 cases and in the midbrain in three cases. The death rate directly related to the hemorrhage was 14/25 (12 early and two delayed deaths). Prognosis factors were the size of the hemorrhage, a ventricular bleeding, disorders of consciousness and pupillary abnormalities on admission, the need for mechanical ventilation.

CONCLUSION

In brain stem hemorrhage, the size of the hematoma is a more important prognosis factor than age or etiological factors.

Cavernomes du tronc cérébral: l'expérience chirurgicale du centre hospitalier Sainte-Anne

BACKGROUND AND PURPOSE

No standard treatment for brainstem cavernoma has been established because of the lack of sufficient data about the natural history of these lesions in a highly functional location with potential difficult surgical accessibility.

METHODS

We present a series of 82 brainstem cavernomas managed at the Sainte-Anne Hospital. Surgery was undertaken for 25 with stereotactic biopsy for 9 and direct surgery for 19 (3 after biopsy).

RESULTS

Surgical outcome was good or fair for 17 patients. Two patients worsened and one died. Biopsy results were disappointing with high morbidity (4 patients with 2 permanent deficits). Histological diagnostic was possible for all biopsies.

CONCLUSION

In light of these results, an active surgical attitude could be proposed for cavernomas in an accessible locations which have produced at least one previous hemorrhage. Stereotactic biopsies for suspect brainstem cavernoma must be avoided.

Histoire naturelle des cavernomes du système nerveux central

We present a critical review of the literature on the central nervous system cavernomas in order to highlight their natural history and to define the most appropriate management of these rare lesions. The prevalence is now estimated from 0.3 to 0.7% in the general population without any significant difference by gender; 25% of cases are pediatric. Two forms of the disease can be described: sporadic forms in 80% of cases, characterized by isolated or rare lesions and familial dominant autosomic forms characterized by multiple and evolutive lesions. The incidence is not well known, the consultation of the French PMSI database suggests that 50 to 100 cases are operated on each year (1 to 2 per million). Cavernomas are dynamic lesions: growing in many cases, seldom remaining quiescent and disappearing in rare cases. The anatomical evolution is more pejorative in familial forms. "De novo" cases are now well known, either in familial or sporadic forms and after radiotherapy. Many lesions are totally asymptomatic, but the frequency of symptomatic forms is debated in the literature from 3 to 90%... The hemorrhagic risk is evaluated from 0,5 to 3% each year, depending on the localization, and the risk of rebleeding is more important but not well known. The epileptic risk is correlated to the localization, more frequent for temporal and frontal lesions from 4,5 to 11% each year, but these data are controversial. The natural history depends on the topography: hemispheric, deep-seated, brain stem, cerebellum or intramedullary and in pediatric situations. Each situation will be treated in this report.

Indications thérapeutiques des cavernomes du système nerveux central

We describe the therapeutic indications for central nervous system cavernomas based on three criteria: 1) Single and multiple lesions: indications are the same, considering that in multiple lesions, one location can be symptomatic; 2) locations: indications are easy to define for exophytic cavernomas close to the hemisphere, brain stem or cerebellum pial surface, or to the ventricular ependyma; 3) symptomatic and non symptomatic presentations: usually, symptomatic forms require surgery except deep lesions located in functional zones distant from the ependyma or the pia matter, unless life prognosis is compromised. Treatment of a symptomatic forms remains debatable, opinion being divided between therapeutic abstention and surgery (in case of cavernomas close to the pia matter or the ependyma). Scientific data strongly support surgical indication for lesions presenting with epilepsy specially when drug-resistant; 4) natural history: prevention against hemorrhage is an argument in favor of surgery for the lesions located in non functional zones or where the risk of bleeding is higher, especially in the brain stem. Discrepancy in the risk of bleeding reported in the literature tends to temper this attitude. Radiosurgery is exceptionally reserved for technically inoperable cavernomas. Partial protection for two years can be expected. Epileptic seizures decrease but few prospective randomised studies are available. The rate of complication appears to be higher than in other affections.

Cavernomes profonds (corps calleux, intraventriculaires, ganglions de la base, insulaires) et du tronc cérébral. Expérience d'une série brésilienne

With a review of the literature, we report our experience with surgical treatment of deep-seated cavernomas (intraventricular, of the corpus callosum, the capsula interna, the insula and the brain stem). Outcome was good in all nine patients after surgery for deep-seated brain cavernomas. There we also 13 cases of the brain stem cavernomas treated surgically. Of them, nine patients were stabilized or improved, one patient worsened, one patient died and two were lost to follow-up. Whatever the location, surgery should only concern symptomatic or hemorrhagic lesions close to the pia-matter or the ependyma as well as those covered by a thin layer of parenchyma. Neuronavigation and microsurgical procedures are essential in the treatment of deep-seated cavernomas.

Biological activity of paediatric cerebral cavernomas: an immunohistochemical study of 28 patients

OBJECTIVE

According to the hypothesis that paediatric cerebral cavernomas may have different biological activity compared to adult cavernomas, immunohistochemical analysis was used to elucidate the biological nature of paediatric cavernomas.

PATIENTS AND METHODS

We examined the histological features and the proliferative and angiogenic capacity of the tissue specimens acquired from 28 paediatric patients. Normal paediatric brain tissues obtained from paediatric autopsy cases were used as a control group. The proliferative activity of the endothelium and the neoangiogenetic capacity were investigated by immunohistochemistry for proliferating cell nuclear antigen (PCNA), Ki-67 epitope (MIB-1), Flk-1 receptor, vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF)-1 alpha, and endoglin antibody, respectively. Afterwards, the results of the paediatric lesions were analysed and compared with the correspondent values of previously reported immunohistochemical analysis in adult cavernomas.

RESULTS

Positive immunostaining of VEGF was detected significantly less in paediatric cavernomas compared to adult cases (p<0.05). In contrast, endoglin, a protein that is upregulated during an increased vascular shear stress, was expressed more often in paediatric cavernomas (p<0.05). Neither the expression of the PCNA nor the expression of the HIF-1alpha was found significantly different between paediatric and adult cavernomas. However, the positive immunoreaction for MIB-1 occurred more often in the paediatric cases (p<0.05).

CONCLUSIONS

The immunohistochemical study indicates that paediatric cavernomas are dynamic lesions. The VEGF/Flk-1 associated neoangiogenesis may play a minor role for the biology of paediatric cavernomas, while endoglin seems to act more prominently than previously thought, particularly for the biology of paediatric cavernomas.

Neurosurgical management of cerebellar cavernous malformations

Object

The aim of this study was to analyze cerebellar cavernous malformations (CMs) with respect to epide-miological, clinical, radiological, and therapeutic aspects.

Methods

Between 1984 and 2004, 100 patients were surgically treated for intracranial CMs at the Division of Neurosurgery of Federal University of São Paulo. The authors reviewed the records of 10 patients whose lesions were located in the cerebellum.

There were four male and six female patients (ratio 1:1.5) whose ages ranged from 14 to 45 years (mean age 33 years). Clinical presentation was sudden or acute in all cases, and neuroimaging examinations performed in all patients demonstrated signs of bleeding. The mean size of the malformations was 4.6 cm, and in all but one patient the lesions were totally removed without complications. After a mean follow-up period of 70 months, all patients were considered to be in good or excellent clinical condition.

Conclusions

Cerebellar CMs should be analyzed separately from other posterior fossa CMs. These lesions can reach large sizes and cause massive hemorrhages, resulting in acute or sudden presentation. Surgery is a safe and effective option that provides a curative treatment when a complete removal is achieved.

Image-guided Transsylvian, Transinsular Approach for Insular Cavernous Angiomas

OBJECTIVE

Surgical treatment of cavernomas arising in the insula is especially challenging because of the proximity to the internal capsule and lenticulostriate arteries. We present our technique of image guidance for operations on insular cavernomas and assess its clinical usefulness.

METHODS

Between 1997 and 2003, with the guidance of a frameless stereotactic system (BrainLab AG, Munich, Germany), we operated on eight patients who harbored an insular cavernoma. Neuronavigation was used for 1) accurate planning of the craniotomy, 2) identification of the distal sylvian fissure, and, finally, 3) finding the exact site for insular corticotomy. Postoperative clinical and neuroradiological evaluations were performed in each patient.

RESULTS

The navigation system worked properly in all eight neurosurgical patients. Exact planning of the approach and determination of the ideal trajectory of dissection toward the cavernoma was possible in every patient. All cavernomas were readily identified and completely removed by use of microsurgical techniques. No surgical complications occurred, and the postoperative course was uneventful in all patients.

CONCLUSION

Image guidance during surgery for insular cavernomas provides high accuracy for lesion targeting and permits excellent anatomic orientation. Accordingly, safe exposure can be obtained because of a tailored dissection of the sylvian fissure and minimal insular corticotomy.

Pericollicular approaches to the rhomboid fossa. Part II. Neurophysiological basis

OBJECT

The authors describe their technique of electrophysiological mapping to assist pericollicular approaches into the rhomboid fossa.

METHODS

Surgical approaches to the rhomboid fossa can be optimized by direct electrical stimulation of superficially located nuclei and fibers. Electrophysiological mapping allows identification of facial nerve fibers, nuclei of the abducent and hypoglossal nerves, motor nucleus of the trigeminal nerve, and the ambiguous nucleus. Stimulation at the surface of the rhomboid fossa performed using the threshold technique allows localization above the area that is located closest to the surface. Simultaneous bilateral electromyographic (EMG) recordings from cranial motor nerves obtained during stimulation document the selectivity of evoked EMG responses. With respect to stimulation parameters and based on morphometric measurements, the site of stimulation can be assumed to be the postsynaptic fibers at the axonal cone. Strict limitation to 10 Hz with a maximum stimulation intensity not exceeding 2 mA can be considered safe. Direct side effects of electrical stimulation were not observed.

CONCLUSIONS

Electrical stimulation based on morphometric data obtained on superficial brainstem anatomy defines two safe paramedian supra- and infracollicular approaches to the rhomboid fossa and is particularly helpful in treating intrinsic brainstem lesions that displace normal anatomical structures.

Brain cavernoma: a dynamic lesion

BACKGROUND

Although the prevalence of brain cavernomas is high (0.50%), for unknown reasons, only a few of them display aggressive clinical behavior.

METHODS

From a personal series of 65 operated and histopathologically verified cavernomas, we have conducted a long-term study, both retrospectively and prospectively, of the main features that cause some cavernomas to be dynamic lesions.

RESULTS

Hemorrhage is the most common phenomenon. Extralesional bleeding due to the rupture of peripheral caverns is most often observed. These are never as immediately devastating as hemorrhages originating from a high-flow, high-pressure AVM. Extralesional hemorrhages tend toward spontaneous resorption, but the risk of recurrence exists and may lead to permanent disability or death (especially when the lesion is located in the brain stem). Intralesional bleeding caused by rupture of contiguous caverns is less frequently observed. This may lead to the formation of large cysts. Calcifications are mostly observed in patients presenting with chronic epilepsy. The bleeding risk of calcified cavernomas is low, but it can exist and should be taken into account in the surgical decision making. The growth of the cavernomatous matrix was obvious in three large cavernomas (two with calcification). No bleeding was found inside the lesions, suggesting a pure "intrinsic" growth. The role of pathologic angiogenic factors is highly probable in these cases. "De novo" appearing lesions were observed in five cases (four belonging to familial forms) on the magnetic resonance imaging survey of operated patients. Perilesional atrophy was observed in three cases (two operated) in patients with a long-lasting evolution. It suggests that the brain metabolism can be disturbed by slow, chronic effusion of blood around the cavernoma.

CONCLUSIONS

The dynamism of cavernomas is determined by extrinsic factors, mainly hemorrhage (with its own consequences); and by intrinsic factors: the pseudotumoral growth of the cavernous matrix. Therefore, when they are symptomatic, cavernomas should be totally removed.

Familial cavernous malformations in a large French kindred: mapping of the gene to the CCM1 locus on chromosome 7q

OBJECTIVES

To characterise clinically a large French family affected with cerebral cavernomas and to check for linkage of this condition to chromosome 7.

METHODS

A family, originating from Normandy and in which five members had undergone surgery for cavernomas, was extended. All members older than 18 were studied clinically and by neuroimaging. Genetic linkage analysis was conducted using 11 polymorphic microsatellite markers located between D7S502 and D7S479.

RESULTS

The family included three generations. Among the 25 members investigated, 11 had an abnormal cerebral MRI, eight of them being symptomatic, and 12 were asymptomatic with a normal MRI. The status of the two remaining members could not be established on the basis of clinical and MRI data. The family reported shares some striking features with other previously linked families--namely, a high clinical penetrance and the presence of multiple lesions within most of the affected members. A lod score of 4.04 was obtained with marker D7S657 with no recombinant. Significant lod scores were also obtained with D7S524 (Zmax=3.32 at 0=0.00) and D7S630 (Zmax=3.44 at 0=0.00). These results establish linkage of the condition found in this family to chromosome 7. Haplotype analysis strongly suggests that the gene is telomeric to D7S802 and centromeric to D7S479.

CONCLUSIONS

These data confirm linkage of cerebral cavernous malformations to chromosome 7 in a non-Hispanic family.