The benefit of neuronavigation for the treatment of patients with intracerebral cavernous malformations

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.

Risk Factors for Poor Postoperative Outcome and Epileptic Symptoms in Patients Diagnosed with Cerebral Cavernous Malformations

BACKGROUND AND STUDY OBJECTIVE

 Roughly 12 to 47% of individuals with cerebral cavernous malformations (CCM) are asymptomatic, while other people may present with symptoms such as epileptic seizures, neurologic deficits, and intracerebral hemorrhages (IH). The aim of this study was to report our experience of postoperative outcomes of patients diagnosed with CCMs.

PATIENTS AND METHODS

 We present a series of consecutive patients who underwent surgical treatment for a diagnosed CCM between January 2003 and March 2014. Data were retrospectively analyzed with respect to preoperative visits, operating reports, patient admission charts, and postoperative follow-up visits. The Engel scale was used to evaluate the outcome of patients with epileptic seizures.

RESULTS

 A total of 91 patients were included with a mean age of 38.8 ± 15 years (range: 2-72 years). Prior to surgery, 57 of these patients had epileptic seizures, while 25 patients recorded at least one episode of IH with a latency time of 6.7 ± 8.5 years (range: 3-240 months) in between hemorrhages. A CCM located within the brainstem was significantly associated with IH prior to surgery (p = 0.000). If the CCM was adjacent to an eloquent brain area, the postoperative outcome in terms of seizure control was significantly worse (p = 0.033). In addition, a trend for worsened outcomes according to the Engel scale was observed in patients with more than one seizure prior to surgery (p = 0.055).

CONCLUSION

 Proximity of CCMs to eloquent brain areas is a risk factor for poor postoperative outcome with respect to a lower rate of medication reduction as well as a lower rate of epileptic seizure omission. This underlines the importance of patient-specific therapeutic approaches.

Application of functional imaging, neuronavigation, and intraoperative MR imaging in the surgical treatment of brain cavernomas

Objective: The aim of this study was to investigate whether preoperative functional imaging and intraoperative magnetic resonance imaging (iMRI) facilitate surgery and improve outcomes in the surgical treatment of cavernous malformations of the brain (CM).Materials and Methods: Retrospective data analysis was performed for consecutive patients diagnosed with a CM who underwent surgical treatment at a single academic institution during a 12 year period. A total of 91 patients was eligible for analysis with a mean age of 38.8 ± 15 years (range 2-72 years). Altogether, 89.0% of CM had supratentorial and 11% infratentorial location.Results: Neuronavigation and iMRI was used in 69 (75.8%) patients with 28 (30.8%) of them together with functional MRI (fMRI) all in the supratentorial location. In 4.3% (3 cases) an intraoperative second-look surgery was performed. Altogether, a complete resection was achieved in 93% of the patients. In supratentorial surgeries, surgical times were significantly shorter in the fMRI group (p = 0.036), but altogether, infratentorial CM surgery took significantly longer (p = 0.014). Moreover, in the fMRI group, reduction of seizure medication was achieved significantly more often (p = 0.026). At an FU of 6.1± 3.1 years, 96% of the patients were assessed modified Rankin Scale 0 or 1.Conclusion: Neuronavigation together with intraoperative and functional MRI had a significant impact on resection amount, surgical time, and neurological and seizure outcome of supratentorial CM. In addition, iMRI was beneficial in few-selected cases.

Outcomes of basal ganglia and thalamic cavernous malformation surgery: A meta-analysis

Surgical resection of basal ganglia (BG) and thalamic cavernous malformations (CMs) has not yet become standardized in the field of neurosurgery due to the eloquent location of these lesions and the relative paucity of literature on the subject. This review presents a consolidation of the available literature on outcomes and complication rates after surgical resection of these lesions. A systematic literature review was performed via PubMed database for articles published between 1985 and 2019. Studies comprising ≥2 patients receiving surgery for BG or thalamic CMs with available follow-up data were included. Pooled data included patient demographics, CM preoperative characteristics, and surgical outcomes Twenty studies comprising 227 patients were included for analysis. Complete resection was achieved in 94.7% (fixed-effects pooled estimate [FE]: 94.9%[91.0%-97.8%]; random-effects pooled estimate [RE]: 90.0%[79.8%-96.9%]), and hemorrhage of incompletely resected CMs occurred in 50% (FE: 55.9%[25.9%-83.6%]; RE: 55.9%[25.9%-83.6%]) of patients. Early morbidity was observed in 24.0% (FE: 24.9%[17.8%-32.6%]; RE: 24.9%[17.8%-32.6%]). At final follow-up, 67.3% (FE: 67.7%[58.8%-76.0%]; RE: 67.8%[52.2%-81.6%]) and 20.6% (FE: 20.6%[13.6%-28.6%]; RE: 20.9%[9.8%-34.9%]) had improvement and stability of preoperative symptoms, respectively. Mortality rate was 1.3% (FE: 2.3%[0.6%-5.1%]; RE: 2.3%[0.6%-5.1%]). Therefore, high cure rates with low rates of postoperative morbidity can be achieved in BG or thalamic CM surgery. Most patients had improved neurological function at final follow-up. Complete resection should be attempted to reduce rates of repeat hemorrhage.

Giant cavernous malformations: A single center experience and literature review

Intracranial giant cavernous malformations (GCMs) are rarely reported because of their extremely low incidence. Knowledge of GCM is poor. The goals of this study were to analyze the epidemiological characteristics, clinical manifestations, radiological findings, microsurgical treatment, and neurological outcomes of GCMs. From January of 2003 to December 2016, nine GCM patients who underwent neurosurgical treatment at Beijing Tiantan Hospital were chosen for analysis and their records were reviewed. We also performed an exhaustive literature search and identified all previously reported GCMs. The study population consisted of three males and six females (mean age, 25.1 years). The mean diameter of the malformations was 6.7 cm (range, 6.0-8.4 cm). The most common clinical manifestations were the symptoms caused by mass effect. Radiologically, all GCMs showed mixed T1 and T2 signals; five of them exhibited minimal enhancement after contrast administration. Gross total resection was achieved in all patients without surgical mortality. Postoperatively, three patients developed new surgical complications, including left limbs weakness and left side paralysis. The mean follow-up period after diagnosis was 69.3 months (range, 16-149 months); five patients (55.6%) had achieved full recovery and the remaining four cases (44.4%) were improved to some extent. GCM is a rare subgroup of vascular malformations; it is more prone to occur in children and adolescents. Microsurgical resection should be the treatment of choice for GCMs, and despite their giant size, excellent surgical outcomes after total removal could be achieved.

Visual Field Preservation in Surgery of Occipital Arteriovenous Malformations: A Prospective Study

OBJECTIVE

We reviewed our prospective study of patients with occipital arteriovenous malformations (AVMs) to assess whether the display of optic radiation diffusion tensor imaging (DTI) during neuronavigation-guided surgery can reduce the severity of postoperative visual field deficits (VFDs) and to evaluate the factors associated with visual field preservation.

METHODS

Forty-six consecutive patients with occipital AVMs were randomized in our study. DTI of the optic radiation was displayed during neuronavigation surgery in 24 patients. The other 22 patients were treated surgically without neuronavigation. Modified Rankin Scale (mRS) scores and visual fields were evaluated preoperatively, immediately after surgery, and at the last follow-up.

RESULTS

The patients' baseline characteristics and AVM features were statistically similar between the 2 surgical groups. The postoperative obliteration rate was 100%. The postoperative mRS scores did not differ between the 2 groups (P > 0.05). Preexisting VFDs were more common (P = 0.00004) in patients who bled than in those with unruptured AVMs. The application of DTI-incorporated neuronavigation reduced the frequency and severity of postoperative VFDs (P = 0.013 and 0.001, respectively). Visual fields were more likely to be preserved in patients with an AVM >5 mm from the optic radiation (P = 0.025).

CONCLUSIONS

A history of hemorrhage is an independent risk factor for VFDs associated with occipital AVMs. Although not showing superiority in postoperative mRS, functional MRI navigation-guided surgery may help to radically resect occipital AVMs and preserve patient visual fields. A 5-mm distance from the optic radiation may be a suitable safety margin for visual field preservation.

Electrocorticography-guided surgical treatment of solitary supratentorial cavernous malformations with secondary epilepsy

OBJECTIVE

To evaluate the efficacy of electrocorticographic (ECoG) monitoring and the application of different surgical approaches in the surgical treatment of solitary supretentorial cavernous malformations with secondary epilepsy.

METHODS

This study enrolled a consecutive series of 36 patients with solitary supratentorial cavernous malformations and secondary epilepsy who underwent surgery with intraoperative ECoG monitoring in the Department of Neurosurgery between January 2004 and January 2008. The patients were composed of 15 males and 21 females, aged between 8 and 52 years (mean age 27.3±2.8 years) at the time of surgery. Epilepsy history, the type of epilepsy at the presentation, lesion location, the incidence of residual epileptiform discharges, and postoperative outcomes were evaluated.

RESULTS

Histopathological examination indicated cavernous malformations and hippocampal sclerosis in 36 and 5 cases, respectively. Neuronal degeneration, glial cell proliferation, and neurofibrillary tangles were found in all the resected cerebral tissues of extended lesionectomy of residual epileptic foci. Lesionectomy, anterior temporal lobectomy, anterior temporal lobectomy plus cortical thermocoagulation, extended lesionectomy, extended lesionectomy plus cortical thermocoagulation were performed in 4, 4, 1, 14, and 13 cases, respectively. Residual epileptiform discharges were captured in 9 out of the 14 patients who had additional cortical thermocoagulation. According to Engle class for postoperative outcomes, 27 cases were class I (75.00%), 5 were class II (13.89%), 2 were class III (5.56%), and 2 were class IV (5.56%), thus the total effective rate (class I+class II) was 88.89%. Neither of epilepsy history, the type of epilepsy, and the location of cavernous malformation was significantly related to outcomes (P>0.05). A significant relationship was found between the incidence of residual epileptiform discharges and outcomes (P=0.041).

CONCLUSIONS

Intraoperative ECoG monitoring, the application of different surgical approaches, and the resection of residual epileptic foci could produce good result in the surgical treatment of supratentorial cavernous malformation with secondary epilepsy. Postoperative residual epileptiform discharges could be a useful predictor for evaluating the outcomes.

Cavernous malformation of brainstem, thalamus, and basal ganglia: a series of 176 patients

BACKGROUND

Cavernous malformations (CMs) in deep locations account for 9% to 35% of brain malformations and are surgically challenging.

OBJECTIVE

To study the clinical features and outcomes following surgery for deep CMs and the complication of hypertrophic olivary degeneration (HOD).

METHODS

Clinical records, radiological findings, operative details, and complications of 176 patients with deep CMs were reviewed retrospectively.

RESULTS

Of 176 patients with 179 CMs, 136 CMs were in the brainstem, 27 in the basal ganglia, and 16 in the thalamus. Cranial nerve deficits (51.1%), hemiparesis (40.9%), numbness (34.7%), and cerebellar symptoms (38.6%) presented most commonly. Hemorrhage presented in 172 patients (70 single, 102 multiple). The annual retrospective hemorrhage rate was 5.1% (assuming CMs are congenital with uniform hemorrhage risk throughout life); the rebleed rate was 31.5%/patient per year. Surgical approach depended on the proximity of the CM to the pial or ependymal surface. Postoperatively, 121 patients (68.8%) had no new neurological deficits. Follow-up occurred in 170 patients. Delayed postoperative HOD developed in 9/134 (6.7%) patients with brainstem CMs. HOD occurred predominantly following surgery for pontine CMs (9/10 patients). Three patients with HOD had palatal myoclonus, nystagmus, and oscillopsia, whereas 1 patient each had limb tremor and hemiballismus. At follow-up, 105 patients (61.8%) improved, 44 (25.9%) were unchanged, and 19 (11.2%) worsened neurologically. Good preoperative modified Rankin Score (98.2% vs 54.5%, P = .001) and single hemorrhage (89% vs 77.3%, P < .05) were predictive of good long-term outcome.

CONCLUSION

Symptomatic deep CMs can be resected with acceptable morbidity and outcomes. Good preoperative modified Rankin Score and single hemorrhage are predictors of good long-term outcome.

Cavernous malformations of the basal ganglia in children

OBJECT

Cavernous malformations (CMs) of the basal ganglia are relatively rare lesions that can lead to considerable neurological impairment because of their eloquent location. The authors reviewed the clinical course and surgical outcome of a series of children with basal ganglia CMs.

METHODS

The authors retrospectively reviewed the operative experience of the senior author (R.M.S.) and the 1997-2011 database of Boston Children's Hospital for children with CM of the basal ganglia (which includes CM of the caudate and/or lentiform nucleus and excludes CM of the thalamus). They evaluated baseline demographics, presenting signs, operative outcomes, and condition at long-term follow-up visits and compared these characteristics among patients who underwent surgery and those who were observed.

RESULTS

Of 180 children with a diagnosis of CM, 11 (6%) had CM of the basal ganglia. The mean age at diagnosis was 9.3 years, and the male/female ratio was 1.8:1. Presenting signs were as follows: hemorrhage (8 children), incidental lesions (2), and seizures (1); 2 children had choreiform movement disorders. Treatment was observation or surgery. Observation was chosen for 5 children either because the lesions were asymptomatic (2 children) or because the risk for neurological dysfunction after attempted excision was believed to be high (3 children). These 5 children were observed over a combined total of 30.4 patient-years; none experienced neurological deterioration or symptomatic hemorrhage from their lesions. The other 6 children underwent microsurgical resection of the lesion because they were symptomatic from hemorrhage or increasing mass effect. All 6 of these children had hemorrhagic lesions, of which the smallest dimension was at least 1.5 cm. Of these 6 lesions, 5 were excised completely, and over a combined total of 46 patient-years of follow-up, no rebleeding or late neurological deterioration after surgery was reported.

CONCLUSIONS

In this patient population, the natural history of small and asymptomatic CMs of the basal ganglia was benign. The children with large (> 1.5 cm) symptomatic lesions underwent excision; neurological impairment was apparently minimal, and no hemorrhage or neurological deterioration occurred later.

Intraoperative high-field magnetic resonance imaging combined with fiber tract neuronavigation-guided resection of cerebral lesions involving optic radiation

BACKGROUND

Intraoperative magnetic resonance imaging (iMRI) combined with optic radiation neuronavigation may be safer for resection of cerebral lesions involving the optic radiation.

OBJECTIVE

To investigate whether iMRI combined with optic radiation neuronavigation can help maximize tumor resection while protecting the patient's visual field.

METHODS

Forty-four patients with cerebral tumors adjacent to the optic radiation were enrolled in the study. The reconstructed optic radiations were observed so that a reasonable surgical plan could be developed. During the surgery, microscope-based fiber tract neuronavigation was routinely implemented. The lesion location (lateral or not to the optic radiation) and course of the optic radiation (stretched or not) were categorized, and their relationships to the visual field defect were determined.

RESULTS

Analysis of the visible relationship between the optic radiation and the lesion led to a change in surgical approach in 6 patients (14%). The mean tumor residual rate for glioma patients was 5.3% (n = 36) and 0% for patients with nonglioma lesions (n = 8). Intraoperative MRI and fiber tract neuronavigation increased the average size of resection (first and last iMRI scanning, 88.3% vs 95.7%; P < .01). Visual fields after surgery improved in 5 cases (11.4%), exhibited no change in 36 cases (81.8%), and were aggravated in 3 cases (6.8%).

CONCLUSION

Diffusion tensor imaging information was helpful in surgical planning. When iMRI was combined with fiber tract neuronavigation, the resection rate of brain lesions involving the optic radiation was increased in most patients without harming the patients' visual fields.

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.

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.

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.