Brainstem Cavernous Malformations Research Articles

Radiosurgery versus observation for brainstem cavernous malformations: a 5-year multicentre cohort study.

The role of radiosurgery in preventing haemorrhage in brainstem cavernous malformations remains a subject of debate. This study aims to evaluate whether radiosurgery provides a protective benefit against haemorrhage in these patients. This multicentre, prospective observational study was conducted in 17 centres and enrolled eligible patients with brainstem cavernous malformations consecutively. Data collected included clinical baseline information, radiosurgery planning details, periodic follow-up evaluations, and any adverse radiation effects. The primary outcome of the study was the incidence of first prospective haemorrhage, while the secondary outcome was the development of new or worsening neurological dysfunctions. The impact of radiosurgery was assessed using multivariate Cox regression analysis. From March 2016 to August 2018, the study enrolled 377 patients: 280 in the observation group receiving standard care alone and 97 in the radiosurgery group receiving both radiosurgery and standard care. The overall cohort consisted of 173 females (45.9%) with a mean age of 40.5 years (range, 18-68 years), and there were no significant differences in baseline characteristics between the two groups. After a median follow-up period of 70 months, haemorrhage occurred in 25.0% (n = 70) of patients in the observation group and 10.3% (n = 10) of patients in the radiosurgery group. Multivariate Cox regression analysis identified radiosurgery as an independent protective factor against haemorrhage (hazard ratio 0.379, 95% confidence interval 0.195-0.738, P = 0.004). Following 1:2 propensity score matching, the incidence of prospective haemorrhage were 24.9% (45/181) in the observation group compared to 10.3% (10/97) in the radiosurgery group (hazard ratio 0.379, 95% confidence interval 0.190-0.755, P = 0.006). Adverse radiation effects were observed in 12 patients (12.4%), with none were permanent. Additionally, new or worsening neurological dysfunctions were significantly more common in the observation group (28.9%) compared to the radiosurgery group (16.5%) (P = 0.016). These results suggest that radiosurgery is associated with a low rate of haemorrhage in patients with brainstem cavernous malformations and could provide a benefit in selected patients. However, further research is required to confirm these findings.

Complete removal of a cavernous malformation in the dorsal pons, in contact with the expanded transpontine vein: illustrative case.

Craniotomy is required for the removal of brainstem cavernous malformations (CMs) with repeated hemorrhage, and this condition is often complicated by an accompanying developmental venous anomaly (DVA). However, a DVA of the brainstem or cerebellum with drainage penetrating the pons is an exceptional finding. A 57-year-old man presented with double vision. Computed tomography revealed progressive enlargement of the hemorrhage in the dorsal pons. Contrast-enhanced magnetic resonance angiography revealed an expanded transverse vessel penetrating the center of the pons in contact with the CM. Digital subtraction angiography revealed that the DVA, comprising the expanded transpontine vein and some cerebellar medullary veins acting as normal venous drainage, coexisted with the CM. By utilizing the angioarchitecture and intraoperative neuronavigation system data, electrophysiological mapping, and indocyanine green videoangiography, complete removal of the CM was accomplished while preserving the DVA and brain function. This study presents the intraoperative images of an expanded transpontine vein as a DVA, which has never been depicted in a live patient before, accompanied by a CM in the dorsal portion of the pons. https://thejns.org/doi/10.3171/CASE24314.

Development and Validation of a Supplementary Grading Scale for Outcomes of Brainstem Cavernous Malformations.

Surgical risk assessment is intriguing for clinical decision-making of brainstem cavernous malformation (BSCM) treatment. While the BSCM grading scale, encompassing size, developmental venous anomaly, crossing axial midpoint, age, and timing of intervention, is increasingly utilized, the clinical relevance of neurological fluctuation and recurrent hemorrhage has not been incorporated. This study aimed to propose a supplementary grading scale with enhanced predictive efficacy. Using a retrospective nationwide registry of consecutive patients with BSCMs undergoing surgery in China from March 2011 to May 2023, a new supplementary BSCM grading scale was developed from a derivative cohort of 260 patients and validated in an independent concurrent cohort of 67 patients. The primary outcome was unfavorable neurological function (modified Rankin Scale score >2) at the latest follow-up. The performance of the supplementary grading system was evaluated for discrimination, calibration, and clinical utility and further compared with its original counterpart. Over a follow-up of at least 6 months after surgery, the unfavorable outcomes were 31% in the overall cohort (101/327 patients). A preoperative motor deficit (odds ratio, 3.13; P=0.001), recurrent hemorrhage (odds ratio, 3.05; P<0.001), timing of intervention (odds ratio, 7.08; P<0.001), and crossing the axial midpoint (odds ratio, 2.57; P=0.006) were associated with the unfavorable outcomes and composed the initial Huashan grading variables. A supplementary BSCM grading system was subsequently developed by incorporating the Huashan grading variables into the original BSCM grading scale. The predictive capability of the supplementary scale was consistently superior to the original counterpart in either the derivative cohort (area under the receiver operating characteristic curve, 0.74 [95% CI, 0.68-0.80] for the supplementary versus 0.68 [95% CI, 0.61-0.74] for the original) or the validation cohort (0.75 [95% CI, 0.62-0.87] versus 0.64 [95% CI, 0.48-0.81]). This study highlights the neurological relevance of BSCM hemorrhage in surgical risk assessment. Via compositing preoperative motor function and recurrent hemorrhages, a supplementary grading scale may improve a dynamic risk assessment for clinical decisions in the management of BSCMs.

One-Point Technique in Brainstem Cavernous Malformation Surgery: Evaluation of Approaches and Outcomes From a Different Perspective.

Brainstem cavernous malformations (BCMs) are a distinct clinical entity that carry a high risk of patient morbidity because of location and risk of hemorrhage. Surgical management of these lesions requires intimate knowledge of surgical anatomy and skull base approaches. This article is intended to highlight a modern approach for the treatment of BCMs, with an emphasis on the use of the one-point technique to guide resection. We describe a case series of BCMs treated through a variety of skull base approaches, describing our decision-making strategy. We review the concept of the one-point technique focusing on the safest access to the malformation through 2 representative cases and also perform a retrospective review of 32 consecutive patients who underwent BCM resection to present outcomes and the comparison of two-point vs one-point techniques. Consecutive series of 32 patients in whom the one-point technique was used is presented. In 8 patients (25%), the traditional two-point technique would suggest a different trajectory than the one-point technique. Postoperative MRI confirmed complete resection in 30 patients (95%), and 29 patients (91%) had modified Rankin Scale (0-2) at follow-up. All patients in whom the one-point technique guided a different trajectory had gross total removal of the cavernous malformation, with one patient having long-term new neurological impairment from the surgery. There were no mortalities. Despite surgical advances in recent decades and more widespread understanding of surgical anatomy and safe entry zones, surgical resection of BCMs remains a formidable challenge. While not necessarily the shortest access, the one-point technique offers a safe approach considering all the different modalities in our armamentarium and can be used as part of a strategy to determine the optimal approach to resect BCMs.

Expanding the reach of the trans-middle cerebellar peduncle approach: pontine cavernous malformations, tissue transgression beyond the safe entry zone, and the invisible triangle.

In the authors' microsurgical experience, the trans-middle cerebellar peduncle (MCP) approach to the lateral and central pons has been the most common approach to brainstem cavernous malformations (BSCMs). This approach through a well-tolerated safe entry zone (SEZ) allows a wide vertical or posterior trajectory, reaching pontine lesions extending into the midbrain, medulla, and pontine tegmentum. Better understanding of the relationships among lesion location, surgical trajectory, and long-term clinical outcomes could determine areas of safe passage. A single-surgeon cohort study of all primary trans-MCP BSCM resections was conducted from July 1, 2017, to June 30, 2021. Preoperative and postoperative MR images were independently reviewed by 3 investigators blinded to the intervention, using a standardized rubric to define BSCM regions of interest (ROIs) involved with a lesion or microsurgical tract. Statistical testing, including the chi-square test with the Bonferroni correction, logistic regression, and structural equation modeling, was performed to analyze relationships between ROIs and clinical outcomes. Thirty-one patients underwent primary trans-MCP BSCM resection during the study period. The median age was 50 years (IQR 24-49 years); 19 (61%) patients were female, and 12 (39%) were male. Seven (23%) patients had familial cavernous malformation syndromes. The median follow-up was 9 months (range 6-37 months). At the last follow-up, composite neurological outcomes were favorable: 22 (71%) patients had 0 (n = 12, 39%) or 1 (n = 10, 32%) major persistent deficit, 5 patients (16%) had 2 deficits, 2 (7%) had 3 deficits, and 1 patient each (3%) had 4 or 6 deficits. Unfavorable composite outcomes were significantly associated with lesions (OR 7.14, p = 0.04) or surgical tracts (OR 12.18, p < 0.001) extending from the superior cerebellar peduncle (SCP) into the contralateral medial midbrain. The ipsilateral dorsal pons was the most frequently implicated ROI involving a surgical tract and the development of new postoperative deficits. This region involved the rhomboid pontine territory and transgression of the pontine tegmentum (OR 7.53, p < 0.001). Structural equation modeling supported medial midbrain and pontine tegmentum transgression as the primary drivers of morbidity. Trans-MCP resection is a safe and effective treatment for BSCMs, including lesions with marked superior or inferior ipsilateral extension. Two trajectories are associated with increased neurological risk: first, a superomedial trajectory to lesions extending into the midbrain that transgresses the SCP, its decussation, or both; and second, a posteromedial trajectory to lesions extending into the pontine tegmentum. The corticospinal tract, SCP, and pontine tegmentum form an invisible triangle within the pontine white matter tolerant of transgression. When the surgeon works within this triangle, most deep pontine BSCMs, including large lesions, those with contralateral or posterior extension, and others extending into the midbrain and medulla, can be resected safely with the trans-MCP approach.

A taxonomy for deep cerebral cavernous malformations: subtypes of basal ganglia lesions.

Anatomical taxonomy is a practical tool that has successfully guided clinical decision-making for patients with brain arteriovenous malformations and brainstem cavernous malformations (CMs). Deep CMs are similarly complex lesions that are difficult to access and highly variable in size, shape, and position. The authors propose a novel taxonomy for deep CMs in the basal ganglia based on clinical presentation (syndromes) and anatomical location. The taxonomy system was developed and applied to an extensive 2-surgeon experience over 19 years (2001-2019). Lesions involving the basal ganglia were identified and subtyped on the basis of the predominant superficial presentation identified on preoperative MRI. Three subtypes of basal ganglia CMs were defined: caudate (31, 57%), putaminal (16, 30%), and pallidal (7, 13%). Neurological outcomes were assessed using the modified Rankin Scale (mRS). Postoperative mRS scores ≤ 2 were defined as a favorable outcome, and scores > 2 were defined as a poor outcome. Clinical and surgical characteristics and neurological outcomes were compared among subtypes. Fifty-four basal ganglia lesions were identified in 54 patients. Each basal ganglia CM subtype was associated with a recognizable constellation of neurological symptoms. The most common symptoms at presentation were severe or worsening headaches (25, 43%), mild hemiparesis (13, 24%), seizures (7, 13%), and dysmetria or ataxia (6, 11%). Patients with caudate CMs were the most likely to present with headaches and constitutional symptoms. Patients with putaminal CMs were the most likely to present with hemibody sensory deficits and dysmetria or ataxia. Patients with pallidal CMs were the most likely to present with mild hemiparesis and visual field deficits. A single surgical approach was preferred (> 80% of cases) for each basal ganglia subtype: caudate (contralateral transcallosal-transventricular, 28/31, 90%), putaminal (transsylvian-anterior transinsular, 13/16, 81%), and pallidal (transsylvian supracarotid-infrafrontal, 7/7, 100%). Most patients with follow-up had stable or improved mRS scores postoperatively (94%, 44/47); mRS scores of > 2 at final follow-up did not differ among the 3 basal ganglia subtypes. The study confirms the authors' hypothesis that this taxonomy for basal ganglia CMs meaningfully guides the selection of surgical approach and resection strategy. Furthermore, the proposed taxonomy can increase the diagnostic acumen at the patient bedside, help identify optimal surgical approaches, enhance the consistency of clinical communications and publications, and improve patient outcomes.

Fully endoscopic approach for resection of brainstem cavernous malformations: a systematic review of the literature

BackgroundBrainstem cavernous malformations (BCMs) are benign lesions that typically have an acute onset and are associated with a high rate of morbidity. The selection of the optimal surgical approach is crucial for obtaining favorable outcomes, considering the different anatomical locations of various brainstem lesions. Endoscopic surgery is increasingly utilized in treating of BCMs, owing to its depth illumination and panoramic view capabilities. For intra-axial ventral BCMs, the best surgical options are endoscopic endonasal approaches, following the “two-point method. For cavernous hemangiomas on the dorsal side of the brainstem, endoscopy proves valuable by providing enhanced visualization of the operative field and minimizing the need for brain retraction.MethodsIn this review, we gathered data on the fully endoscopic approach for the resection of BCMs, and outlined technical notes and tips. Total of 15 articles were included in this review. The endoscopic endonasal approach was utilized in 19 patients, and the endoscopic transcranial approach was performed in 3 patients.ResultsThe overall resection rate was 81.8% (18/22). Among the 19 cases of endoscopic endonasal surgery, postoperative cerebrospinal fluid (CSF) leakage occurred in 5 cases, with lesions exceeding 2 cm in diameter in 3 patients with postoperative CSF rhinorrhea. Among the 20 patients with follow-up data, 2 showed no significant improvement after surgery, whereas the remaining 18 patients showed significant improvement compared to their admission symptoms.ConclusionsThis systematic literature review demonstrates that a fully endoscopic approach is a safe and effective option for the resection of BCMs. Further, it can be considered an alternative to conventional craniotomy, particularly when managed by a neurosurgical team with extensive experience in endoscopic surgery, addressing these challenging lesions.

Association of hemorrhage-to-treatment time with outcomes in patients with brainstem cavernous malformations: a nationwide cohort study.

Brainstem cavernous malformations (BSCMs) often present with haemorrhage, but the optimal timing for microsurgical intervention remains unclear. This study aims to explore how intervention timing relates to neurological outcomes in haemorrhagic BSCM patients undergoing microsurgery, offering insights for clinical decisions. A total of 293 consecutive patients diagnosed with BSCMs, who underwent microsurgery were identified between March 2011 and January 2023 at two comprehensive centres in China, with a postoperative follow-up duration exceeding 6 months. Utilizing logistic regression models with restricted cubic splines, distinct time groups were identified. Subsequently, matching weight analysis compared these groups in terms of outcomes, new haemorrhage rates, cranial nerve deficits, and perioperative complications. The primary outcome was an unfavourable outcome, which was defined as a mRS score greater than 2 at the latest follow-up. Among the 293 patients, 48.5% were female, median age was (39.9±14.3) years, and median haemorrhage-to-treatment time was 42 days. Patients were categorized into acute (≤21days), subacute (22-42days), and delay (>42days) intervention groups. After matching, 186 patients were analyzed. Adjusted analysis showed lower unfavourable outcome rates for acute [adjusted odds ratio (OR), 0.73; 95% CI, 0.65-0.82; P<0.001] and subacute (adjusted OR, 0.83; 95% CI, 0.72-0.95; P=0.007) groups compared to the delay group. Subacute intervention led to fewer cranial nerve deficits (adjusted OR, 0.76; 95% CI, 0.66-0.88, P<0.001). New haemorrhage incidence didn't significantly differ among groups. For haemorrhagic BSCMs patients, delayed microsurgical intervention that exceeded 42 days after a prior haemorrhage were associated with an increased risk of unfavourable neurological outcomes.

397 Rehemorrhage of Brainstem Cavernous Malformations: A Benchmark Approach to Individualized Risk and Severity Assessment

INTRODUCTION: Brainstem cavernous malformations (BSCMs) represent a unique subgroup of cavernous malformations with more hemorrhagic presentation and technical challenges. METHODS: A total of 123 consecutive BSCM patients with symptomatic hemorrhage were identified between 2015 and 2022, with untreated follow-up &gt; 12 months or subsequent hemorrhage during the untreated follow-up. Nomograms were proposed to individualize the assessment of subsequent hemorrhage risk and neurological status (determined by the modified Rankin Scale [mRS] score) after future hemorrhage. The least absolute shrinkage and selector operation (LASSO) regression was used for feature screening. The calibration curve and concordance index (C-index) were used to assess the internal calibration and discrimination performance of the nomograms. Cross-validation was further performed to validate the accuracy of the nomograms. RESULTS: Prior hemorrhage times (adjusted OR [aOR] 6.78 per ictus increase) and Zabramski type I or V (OR 11.04) were associated with rehemorrhage within 1 year. A lower mRS score after previous hemorrhage (aOR 0.38 for a shift to a higher mRS score), Zabramski type I or V (OR 3.41), medulla or midbrain location (aOR 2.77), and multiple cerebral cavernous malformations (aOR 11.76) were associated with worsened neurological status at subsequent hemorrhage. The nomograms showed good accuracy and discrimination, with a C-index of 0.80 for predicting subsequent hemorrhage within 1 year and 0.71 for predicting neurological status after subsequent hemorrhage, which were maintained in cross-validation. CONCLUSIONS: An individualized approach to risk and severity assessment of BSCM rehemorrhage was feasible with clinical and imaging features.

Microsurgical Resection of Brainstem Cavernous Malformations in Older Adults: A Multicenter, 30-Year Experience.

Microsurgical resection is the only curative intervention for symptomatic brainstem cavernous malformations (BSCMs), but the management of these lesions in older adults (≥65 years) is not well described. This study sought to address this gap by examining the safety and efficacy of BSCM resection in a cohort of older adults. Records of patients who underwent BSCM resection over a 30-year period were reviewed retrospectively. Baseline characteristics and outcomes were compared between older (≥65 years) and younger (<65 years) patients. Of 550 patients with BSCM who met inclusion criteria, 41 (7.5%) were older than 65 years. Midbrain (43.9% vs 26.1%) and medullary lesions (19.5% vs 13.6%) were more common in the older cohort than in the younger cohort ( P = .01). Components of the Lawton BSCM grading system (ie, lesion size, crossing axial midpoint, developmental venous anomaly, and timing of hemorrhage) were not significantly different between cohorts ( P ≥ .11). Mean (SD) Elixhauser comorbidity score was significantly higher in older patients (1.86 [1.06]) than in younger patients (0.66 [0.95]; P < .001). Older patients were significantly more likely than younger patients to have poor outcomes at final follow-up (28.9% vs 13.8%, P = .01; mean follow-up duration, 28.7 [39.1] months). However, regarding relative neurological outcome (preoperative modified Rankin Scale to final modified Rankin Scale), rate of worsening was not significantly different between older and younger patients (23.7% vs 14.9%, P = .15). BSCMs can be safely resected in older patients, and when each patient's unique health status and life expectancy are taken into account, these patients can have outcomes similar to younger patients.

Treatment Modalities and Outcomes in Brainstem Cavernous Malformations: A Large Multicenter Observational Cohort Study.

Symptomatic brainstem cavernous malformations (BSCMs) pose a high risk of morbidity and mortality due to recurrent hemorrhage, warranting aggressive management. However, few studies have compared the effectiveness of different treatment modalities for BSCMs. We aimed to assess the association of treatment modalities with recurrent hemorrhage and neurological outcomes in patients with BSCM. We conducted a retrospective cohort study using an observational registry database covering population of southwest and southeast China. Adult patients with BSCM were included and followed up between March 1, 2011, to March 31, 2023. We compared outcomes between microsurgery and stereotactic radiosurgery (SRS) in propensity score-matched case pairs, incorporating demographic, medical history, and lesion characteristics. The outcomes studied included recurrent hemorrhage and poor prognosis (defined as a Glasgow Outcome Scale score, <4). Absolute rate differences and hazard ratios (HRs) with 95% CIs were calculated using Cox models. Among 736 diagnosed patients with BSCM, 96 (48 matched pairs) were included after exclusions and propensity score matching (mean age, 43.1 [SD, 12.1] years; 50% women). During the median 5-year follow-up, no significant differences in recurrent hemorrhage (4.2% [microsurgery] versus 14.6% [SRS], HR, 3.90 [95% CI, 0.46-32.65]; P=0.21) and poor prognosis (12.5% [microsurgery] versus 8.3% [SRS], HR, 0.29 [95% CI, 0.08-1.08]; P=0.07) were observed between microsurgery and SRS recipients. Furthermore, either microsurgery or SRS correlated with fewer recurrent hemorrhage (HR, 0.09 [95% CI, 0.02-0.39]; P=0.001; HR, 0.21 [95% CI, 0.07-0.69]; P=0.01) compared with conservative treatment. In this study, both microsurgery and SRS were safe and effective for BSCM, demonstrated comparable outcomes in recurrent hemorrhage and poor prognosis. However, interpretation should be cautious due to the potential for residual confounding. URL: https://www.chictr.org.cn/; Unique identifier: ChiCTR2300070907.

Infragalenic triangle as a gateway to dorsal midbrain and posteromedial thalamic lesions: descriptive and quantitative analysis of microsurgical anatomy.

Anatomical triangles provide neurosurgeons with the specificity required to access deep targets, supplementing more general instructions, such as craniotomy and approach. The infragalenic triangle (IGT), bordered by the basal vein of Rosenthal (BVR), precentral cerebellar vein (PCV), and the quadrangular lobule of the cerebellum, is one of a system of anatomical triangles recently introduced to guide dissection to brainstem cavernous malformations and has not been described in detail. This study aimed to quantitatively analyze the anatomical parameters of the IGT and present key nuances for its microsurgical use. A midline supracerebellar infratentorial (SCIT) approach through a torcular craniotomy was performed on 5 cadaveric heads, and the IGT was identified in each specimen bilaterally. Anatomical measurements were obtained with point coordinates collected using neuronavigation. Three cadaveric brains were used to illustrate relevant brainstem anatomy, and 3D virtual modeling was used to simulate various perspectives of the IGT through different approach angles. In addition, 2 illustrative surgical cases are presented. The longest edge of the IGT was the lateral edge formed by the BVR (mean ± SD length 19.1 ± 2.3 mm), and the shortest edge was the medial edge formed by the PCV (13.9 ± 3.6 mm). The mean surface area of the IGT was 110 ± 34.2 mm2 in the standard exposure. Full expansion of all 3 edges (arachnoid dissection, mobilization, and retraction) resulted in a mean area of 226.0 ± 48.8 mm2 and a 2.5-times increase in surface area exposure of deep structures (e.g., brainstem and thalamus). Thus, almost the entire tectal plate and its relevant safe entry zones can be exposed through an expanded unilateral IGT except for the contralateral inferior colliculus, access to which is usually hindered by PCV tributaries. Exposure of bilateral IGTs may be required to resect larger midline lesions to increase surgical maneuverability or to access the contralateral pulvinar. The IGT provides a safe access route to the dorsal midbrain and reliable intraoperative guidance in the deep and complex anatomy of the posterior tentorial incisura. Its potential for expansion makes it a versatile anatomical corridor not only for intrinsic brainstem lesions but also for tumors and vascular malformations of the pineal region, dorsal midbrain, and posteromedial thalamus.

Safety and efficacy of the endoscopic transsphenoidal transclival approach performed using direct cortical stimulation for pontine cavernous malformations.

Surgical treatment of brainstem cavernous malformations (CMs) is challenging. Surgery using the endoscopic transsphenoidal transclival approach (eTSTCA) is reported as a useful alternative for ventral brainstem CMs. However, CMs located in the ventral midline of the brainstem are rare, and only a small number of case reports on these CMs treated with the eTSTCA exist. The efficacy and safety of the eTSTCA have not yet been fully examined. A retrospective analysis was performed for 5 consecutive patients who underwent surgery via the eTSTCA for treating ventral pontine CMs. The average maximum CM diameter was 26.0 mm (18-38 mm). All patients underwent MR-diffusion tensor imaging, which confirmed that the corticospinal tract (CST) deviated posteriorly or laterally to the CM. Direct brainstem cortical stimulation was performed to localize the CST before making the cortical incision. After the excision of the CM, the cavity was filled with artificial CSF to make an aqueous surgical field (wet-field technique) for observing the tumor cavity and confirming complete hemostasis and resection. Total removal was achieved in all patients. The preoperative modified Rankin Scale score was 3 in 3 patients and 4 in 2 patients, whereas it was 1 in 2 patients and 0 in 3 patients 3 months after surgery. Postoperative CSF leakage was observed in 1 patient, and transient abducens nerve palsy was observed in 1 patient. No other intra- or postoperative complications were observed. MR-diffusion tensor imaging and direct brainstem cortical stimulation were useful to ascertain the proximity of the CST to the CM. The endoscope provides a clear view even underwater, and it was safe and effective to observe the entire CM cavity and confirm complete hemostasis without additional retraction of the brainstem parenchyma, including the CST. The eTSTCA provides a direct access point to the lesion and may be a safer alternative treatment for patients whose CST deviates laterally or posteriorly to the CM.

Functional Outcome after Initial and Multiple Intracerebral Hemorrhage in Patients with a Brainstem Cavernous Malformation: a Multicenter Study

Functional Outcome after Initial and Multiple Intracerebral Hemorrhage in Patients with a Brainstem Cavernous Malformation: a Multicenter Study

Long-Term Outcomes of Gamma Knife Radiosurgery for Cerebral Cavernous Malformations: 10 Years and Beyond.

We aimed to evaluate long-term outcomes of gamma knife radiosurgery (GKS) for cerebral cavernous malformations (CCMs). Among the 233 CCM patients who underwent GKS, 79 adult patients (96 lesions) followed for over 10 years were included and analyzed retrospectively. Annual hemorrhage rate (AHR) was analyzed the entire cohort of 233 patients and the subset of 79 enrolled patients by dividing lesions into overall CCM lesions and brainstem lesions. AHR, neurologic outcome, adverse radiation effect (ARE), and changes of lesions in magnetic resonance imaging (MRI) were compared before and after GKS. Cox-regression analysis was performed to identify risk factors for hemorrhage following GKS. Mean follow-up duration of 79 enrolled patients was 14 years (range, 10-23 years). The AHR of all CCMs for entire cohort at each time point was 17.8% (pre-GKS), 5.9% (≤ 2 years post-GKS), 1.8% (≤ 10 years post-GKS). The AHR of all CCM for 79 enrolled patients was 21.4% (pre-GKS), 3.8% (2 years post-GKS), 1.4% (10 years post-GKS), and 2.3% (> 10 years post-GKS). The AHR of brainstem cavernous malformation (CM) for entire cohort at each time point was 22.4% (pre-GKS), 10.1% (≤ 2 years post-GKS), 3.2% (≤ 10 years post-GKS). The AHR of brainstem CM for 79 enrolled patients was 27.2% (pre-GKS), 5.8% (2 years post-GKS), 3.4% (10 years post-GKS), and 3.5% (> 10 years post-GKS). Out of the 79 enrolled patients, 35 presented with focal neurologic deficits at the initial clinical visit. Among these patients, 74.3% showed recovery at the last follow-up. Symptomatic ARE occurred in five (6.4%) patients. No mortality occurred. Most lesions were decreased in size at the last follow-up MRI. Previous hemorrhage history (hazard ratio [HR], 8.38; 95% confidence interval [CI], 1.07-65.88; P = 0.043), and brainstem location (HR, 3.10; 95% CI, 1.26-7.64; P = 0.014) were significant risk factors for hemorrhage event. GKS for CCM showed favorable long-term outcomes. GKS should be considered for CCM, especially when it has a previous hemorrhage history and brainstem location.

A taxonomy for deep cerebral cavernous malformations: subtypes of thalamic lesions.

Anatomical taxonomy is a practical tool to successfully guide clinical decision-making for patients with brain arteriovenous malformations and brainstem cavernous malformations (CMs). Deep cerebral CMs are complex, difficult to access, and highly variable in size, shape, and position. The authors propose a novel taxonomic system for deep CMs in the thalamus based on clinical presentation (syndromes) and anatomical location (identified on MRI). The taxonomic system was developed and applied to an extensive 2-surgeon experience from 2001 through 2019. Deep CMs involving the thalamus were identified. These CMs were subtyped on the basis of the predominant surface presentation identified on preoperative MRI. Six subtypes among 75 thalamic CMs were defined: anterior (7/75, 9%), medial (22/75, 29%), lateral (10/75, 13%), choroidal (9/75, 12%), pulvinar (19/75, 25%), and geniculate (8/75, 11%). Neurological outcomes were assessed using modified Rankin Scale (mRS) scores. A postoperative score ≤ 2 was defined as a favorable outcome and > 2 as a poor outcome. Clinical and surgical characteristics and neurological outcomes were compared among subtypes. Seventy-five patients underwent resection of thalamic CMs and had clinical and radiological data available. Their mean age was 40.9 (SD 15.2) years. Each thalamic CM subtype was associated with a recognizable constellation of neurological symptoms. The common symptoms were severe or worsening headaches (30/75, 40%), hemiparesis (27/75, 36%), hemianesthesia (21/75, 28%), blurred vision (14/75, 19%), and hydrocephalus (9/75, 12%). The thalamic CM subtype determined the selection of surgical approach. A single approach was associated with each subtype for most patients. The main exception to this paradigm was that in the surgeons' early experience, pulvinar CMs were resected through a superior parietal lobule-transatrial approach (4/19, 21%), which later evolved to the paramedian supracerebellar-infratentorial approach (12/19, 63%). Relative outcomes implied by mRS scores were unchanged or improved in most patients (61/66, 92%) postoperatively. This study confirms the authors' hypothesis that this taxonomy for thalamic CMs can meaningfully guide the selection of surgical approach and resection strategy. The proposed taxonomy can increase diagnostic acumen at the patient bedside, help identify optimal surgical approaches, enhance the clarity of clinical communications and publications, and improve patient outcomes.

Hemorrhagic Outcome of Brainstem Cavernous Malformations following Radiosurgery: Dose-Response Relationship

Introduction: This study aimed to assess the impact of gamma knife radiosurgery on brainstem cavernous malformations (CMs). Methods: A total of 85 patients (35 females; median age 41.0 years) who underwent gamma knife radiosurgery for brainstem CMs at our institute between 2006 and 2015 were enrolled in a prospective clinical observation trial. Risk factors for hemorrhagic outcomes were evaluated, and outcomes were compared across different margin doses. Results: The pre-radiosurgery annual hemorrhage rate (AHR) was 32.3% (44 hemorrhages during 136.2 patient-years). The median planning target volume was 1.292 cc. The median margin and maximum doses were 15.0 and 29.2 Gy, respectively, with a median isodose line of 50.0%. The post-radiosurgery AHR was 2.7% (21 hemorrhages during 769.9 patient-years), with a rate of 5.5% within the first 2 years and 2.0% thereafter. The post-radiosurgery AHR for patients with margin doses of ≤13.0 Gy (n = 15), 14.0–15.0 Gy (n = 50), and ≥16.0 Gy (n = 20) was 5.4, 2.7, and 0.6%, respectively. Correspondingly, transient adverse radiation effects were observed in 6.7 (1/15), 10.0 (5/50), and 30.0% (6/20) of cases, respectively. An increased margin dose per 1 Gy (hazard ratio: 0.530, 95% CI: 0.341–0.826, p = 0.005) was identified as an independent protective factor against post-radiosurgery hemorrhage. Margin doses of ≥16.0 Gy were associated with improved hemorrhagic outcomes (hazard ratio: 0.343, 95% confidence interval [CI]: 0.157–0.749, p = 0.007), but an increased risk of adverse radiation effects (odds ratio: 3.006, 95% CI: 1.041–8.677, p = 0.042). Conclusion: The AHR of brainstem CMs decreased following radiosurgery, and our study revealed a significant dose-response relationship. Margin doses of 14–15 Gy were recommended. Further studies are required to validate our findings.

뇌교 및 연수 해면상혈관종에 대한 telovelar 접근법의 수술 결과 및 뉘앙스

Background: Brainstem cavernous malformations (CMs) are characterized by dilated sinusoidal channels related to capillary telangiectasia and developmental venous anomalies. Brainstem CM hemorrhages present with focal neurological symptoms, according to their invasive lesions. Surgical removal should be considered for symptomatic and recurrent bleeding of brainstem CMs. Despite the risk of surgery with highly eloquent tissue, surgical removal should be performed to protect patients from stepwise decline due to recurrent hemorrhage. The approaches for treating brainstem CMs are retrosigmoid, far lateral, midline suboccipital with or without telovelar, orbitozygomatic, and supracerebellar-infratentorial. Pontine and medullary CMs are approached via retrosigmoid, far lateral, and suboccipital craniotomies, with or without the telovelar approach. &#x0D; Materials and Methods: The telovelar approach is the standard approach used for pontine brain-stem CMs. Patients with brainstem CMs treated using the telovelar approach were enrolled from three institutions. &#x0D; Results: All three patients had no further neurological deficits after surgery. &#x0D; Conclusions: The surgical results suggest that the telovelar approach for pons and pontomedul-lary junction brainstem CMs is safe and effective.

Long-term functional outcomes and complications of microsurgical resection of brainstem cavernous malformations: a systematic review and meta-analysis.

Brainstem cavernous malformations (CMs) encompass up to 20% of all intracranial CMs and are considered more aggressive than cerebral CMs because of their high annual bleeding rates. Microsurgical resection remains the primary treatment modality for CMs, but long-term functional outcomes and complications are heterogenous in the literature. The authors performed a systematic review on brainstem CMs in 4 databases: PubMed, EMBASE, Cochrane library, and Google Scholar. We included studies that reported on the long-term functional outcomes and complications of brainstem CMs microsurgical resection. A meta-analysis was performed and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The search yielded 4781 results, of which 19 studies met our inclusion criteria. Microsurgery was performed on 940 patients (mean age 35years, 46.9% females). Most of the brainstem CMs were located in the pons (n = 475). The pooled proportions of improved, stable, and worsened functional outcomes after microsurgical resection of brainstem CMs were 56.7% (95% CI 48.4-64.6), 28.6% (95% CI 22.4-35.7), and 12.6% (95% CI 9.6-16.2), respectively. CMs located in the medulla were significantly (p = 0.003) associated with a higher proportion of improved outcome compared with those in the pons and midbrain. Complete resection was achieved in 93.3% (95% CI 89.8-95.7). The immediate postoperative complication rate was 37.2% (95% CI 29.3-45.9), with new-onset cranial nerve deficit being the most common complication. The permanent morbidity rate was 17.3% (95% CI 10.5-27.1), with a low mortality rate of 1% from the compiled study population during a mean follow-up of 58months. Our analysis indicates that microsurgical resection of brainstem CMs can result in favorable long-term functional outcomes with transient complications in the majority of patients. Complete microsurgical resection of the CM is associated with a lower incidence of CM hemorrhage and the morbidity related to it.

The Brainstem Cavernoma Case Series: A Formula for Surgery and Surgical Technique.

Background and Objectives: Cavernous malformations (CM) are vascular malformations with low blood flow. The removal of brainstem CMs (BS) is associated with high surgical morbidity, and there is no general consensus on when to treat deep-seated BS CMs. The aim of this study is to compare the surgical outcomes of a series of deep-seated BS CMs with the surgical outcomes of a series of superficially located BS CMs operated on at the Department of Neurosurgery, College of Tuebingen, Germany. Materials and Methods: A retrospective evaluation was performed using patient charts, surgical video recordings, and outpatient examinations. Factors were identified in which surgical intervention was performed in cases of BS CMs. Preoperative radiological examinations included MRI and diffusion tensor imaging (DTI). For deep-seated BS CMs, a voxel-based 3D neuronavigation system and electrophysiological mapping of the brainstem surface were used. Results: A total of 34 consecutive patients with primary superficial (n = 20/58.8%) and deep-seated (n = 14/41.2%) brainstem cavernomas (BS CM) were enrolled in this comparative study. Complete removal was achieved in 31 patients (91.2%). Deep-seated BS CMs: The mean diameter was 14.7 mm (range: 8.3 to 27.7 mm). All but one of these lesions were completely removed. The median follow-up time was 5.8 years. Two patients (5.9%) developed new neurologic deficits after surgery. Superficial BS CMs: The median diameter was 14.9 mm (range: 7.2 to 27.3 mm). All but two of the superficial BS CMs could be completely removed. New permanent neurologic deficits were observed in two patients (5.9%) after surgery. The median follow-up time in this group was 3.6 years. Conclusions: The treatment of BS CMs remains complex. However, the results of this study demonstrate that with less invasive posterior fossa approaches, brainstem mapping, and neuronavigation combined with the use of a blunt "spinal cord" dissection technique, deep-seated BS CMs can be completely removed in selected cases, with good functional outcomes comparable to those of superficial BS CM.