Predictors of postoperative epileptic seizures after microsurgical treatment in supratentorial single cerebral cavernous malformations: a retrospective study

PURPOSE

Seizures are the most common symptom of supratentorial cerebral cavernous malformations (CCMs). This study aimed to investigate the predictors of seizure freedom in patients with single supratentorial CCMs after microsurgical treatment.

METHODS

Clinical data were retrospectively obtained from 164 patients with CCM (including 98 patients with preoperative seizures, and 66 patients without preoperative seizures) who underwent microsurgical treatment between January 2016 and December 2023 at the First Affiliated Hospital of Sun Yat-sen University.

RESULTS

After microsurgical treatment, early postoperative seizures (≤ 1 week) occurred in 2 of 98 (2.04%) and 2 of 66 (3.03%) CCM patients with and without preoperative seizures, respectively. The mean length of follow-up for all the patients was 44.70 ± 2.04 months (range: 1-98 months). Sixty-four of the 66 (96.97%) patients without preoperative seizures were seizure free during the follow-up period. Among the patients with preoperative seizures, 77 of 98 (78.57%) patients achieved followed-up seizure remission, including 18 of 28 (64.29%) patients with drug-resistant epilepsy and 59 of 70 (84.29%) patients with drug-controlled epilepsy. Univariate analysis indicated that preoperative seizure duration, drug-resistant epilepsy, tailored resection and the application of intraoperative electrocorticography (ECoG) were important risk factors that affected followed-up seizure remission among patients with preoperative seizures. However, according to multivariate regression, only the use of intraoperative ECoG was an independent predictor related to the followed-up seizure remission.

CONCLUSION

For CCM patients with preoperative seizures, intraoperative ECoG was an independent predictor of followed-up seizure remission. The application of intraoperative ECoG is beneficial for improving seizure outcome among CCM patients after microsurgical treatment, especially among patients with preoperative drug-resistant epilepsy.

Large Pontine Cavernoma with Hemorrhage: Case Report on Surgical Approach and Recovery

Background/Objectives: Pontine cavernomas are rare and challenging vascular malformations, representing a critical subset of brainstem lesions due to their deep location and proximity to essential neural structures. When hemorrhagic, these lesions can cause rapid neurological deterioration, posing life-threatening risks. Management requires a delicate balance between aggressive intervention and preserving vital functions. This case report presents the successful surgical treatment of a giant hemorrhagic pontine cavernoma, highlighting the integration of advanced imaging, precision surgical techniques, and multidisciplinary care to achieve an exceptional patient outcome. Methods: A 47-year-old female presented with acute neurological deterioration, including severe right-sided hemiparesis, dysphagia, and obnubilation. High-resolution MRI, including susceptibility-weighted imaging, confirmed a giant hemorrhagic pontine cavernoma causing brainstem compression. An urgent left-sided pterional craniotomy with a transsylvian approach was performed to access the lesion. Subtotal resection and hematoma evacuation were carried out to relieve brainstem compression while preserving critical structures. Postoperative recovery and lesion stability were evaluated through clinical assessments and imaging after three months. Results: Postoperatively, the patient exhibited marked neurological recovery, with near-complete resolution of hemiparesis, restored swallowing function, and significant functional improvement. Follow-up imaging confirmed a stable residual lesion, no recurrence of hemorrhage, and a well-preserved ventricular system. The combination of early intervention and tailored surgical strategies resulted in a highly favorable outcome. Conclusions: This case underscores the complexity of managing giant hemorrhagic pontine cavernomas and demonstrates that carefully planned surgical intervention, combined with advanced imaging and patient-focused care, can yield remarkable outcomes. It highlights the critical importance of early diagnosis, meticulous surgical planning, and future innovations in neurovascular surgery to improve outcomes in these rare but high-stakes cases.

Improving methodology of radiosurgery for posterior fossa cavernomas: higher volume, lower dose

Cavernous malformations (CM) of the brain are vascular abnormalities that carry a risk of bleeding, posing significant neurological and life-threatening challenges, particularly in posterior fossa. The efficacy of radiosurgery for cavernomas still remains a matter of debate, largely due to technical and statistical limitations. In this study, we present a series of posterior fossa cavernomas treated using CyberKnife radiosurgery, employing an innovative approach that integrates both technical and statistical advancements.

PATIENTS AND METHODS

We conducted a prospective series involving 35 posterior fossa cavernomas in 33 patients treated with low-dose radiosurgery protocols (12 Gy in a single fraction or 18 Gy in 3 fractions). Compared to previously published series, our approach targeted a larger treatment volume, encompassing the entire hemosiderin ring surrounding the cavernoma. Radiosurgery was indicated for cases of hemorrhage or progressive neurological deficits in anatomically challenging, nonsurgical areas. The statistical analysis was designed to address the unknown onset time of cavernoma prior to radiosurgery, enabling a more accurate calculation of the hemorrhage incidence rate before treatment. Follow-up evaluations, including clinical assessments and MRI, were conducted at 3-6-9-12-18-24 months and subsequently on an annual basis.

RESULTS

With a mean follow-up duration of 26 months, exceeding the previously described latency period, and a median [IQR] follow-up of 13 months [8.7-30.4] which represents approximately half the latency period, only one patient experienced a recurrence of hemorrhage, occurring 20 months post-treatment and remaining asymptomatic. No patients exhibited radio-induced parenchymal changes or clinical deterioration following radiosurgery.

CONCLUSIONS

These preliminary results support the strategy of increasing the target volume while reducing the radiation dose for cavernous malformations. We further recommend incorporating sensitivity analyses to evaluate the robustness of results, particularly in the context of uncertainties surrounding the time of onset of cavernomas.

Endoscopic excision of an aqueduct of Sylvius cavernoma causing obstructive hydrocephalus: technical note

BACKGROUND AND IMPORTANCE

Acquired lesions within the aqueduct of Sylvius are rare and their surgical management is challenging. Open transcranial approaches require dissection and manipulation of surrounding eloquent structures. Use of an endoscope can avoid potential morbidity from traversing and handling eloquent structures during open approaches whilst providing better visualisation of an intraventricular lesion.

CLINICAL PRESENTATION

A 62-year-old female presented with insidious onset short-term memory loss, unsteady gait, urinary incontinence and left-sided dysaesthesia. Magnetic resonance imaging (MRI) revealed hydrocephalus from an obstructive haemorrhagic lesion consistent with a cavernoma at the central midbrain within the aqueduct of Sylvius. An endoscopic approach was selected to provide optimal visualisation of the lesion. As only a single instrument could be accommodated, rotational movements were employed to tease out the lesion. Gross total resection was achieved. Her symptoms improved immediately postoperatively and she made a complete recovery by 2 months. Post-operative MRI showed resolution of hydrocephalus and no evidence of residual/recurrence of the lesion. Unfortunately, she developed hydrocephalus 3 months post-op and required placement of a ventriculoperitoneal shunt.

CONCLUSIONS

Endoscopic resection is safe and feasible for selected periaqueductal lesions as it provides direct access while minimising disruption of the surrounding anatomical structures. The limitation of only having a single instrument can be overcome by employing rotational movements.

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

BACKGROUND AND OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Diffusion tensor imaging with tractography in surgical resection of brainstem cavernous malformations: a systematic review and meta-analysis

Brainstem cavernous malformations are benign subset of cerebral cavernous malformations, which need a special intervention owing to being vital and complex. The diffusion tensor imaging technique, a well-recognized neuroimaging tool, can visualize the white matter tracts and their surroundings and provide promising surgical outcomes. This systematic review and meta-analysis evaluated the effect of preoperative diffusion tensor imaging in patients undergoing surgical resection of brainstem cavernous malformations. Five databases, including PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar, were searched using a comprehensive search strategy to find any article matching our inclusion criteria. We used Comprehensive Meta-Analysis (CMA) software to analyze the collected data, get the evidence, and report the results as event rate (ER), with their 95% confidence interval (CI). Twenty-eight studies involving 467 patients matched our criteria and 19 studies entered the analysis. Our analysis showed that, in patients undergoing surgical resection of brainstem cavernous malformations assisted by preoperative diffusion tensor imaging, 82.21% achieved total resection. About 12.4% of patients achieved partial resection, 65.65% improved, 8.07% worsened, 25.04% showed no change, 3.59% experienced postoperative re-bleeding, and 0.87% died. The utilization of preoperative diffusion tensor imaging significantly increased the proportion of improved patients and decreased the proportion of worsened patients. However, further controlled research is needed to draw a definite conclusion about the usefulness of its role.

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

BACKGROUND AND OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Identification of predictive factors for better outcomes in LINAC-based radiation treatment for cerebral cavernous malformation

The effectiveness of radiation therapy in the treatment of cerebral cavernous malformations (CCM) remains debatable. However, numerous studies have shown a reduction in hemorrhage risk following radiotherapy for CCM. Therefore, herein, we share our experiences utilizing linear accelerator (LINAC)-based radiation for treating CCMs, with the aim of identifying the key factors influencing the therapeutic outcomes. We conducted a retrospective review of all patients with non-brainstem CCMs who underwent radiation treatment, as recorded in the NOVALIS registry at our institution. T2-weighted MR images were used for volumetric assessments using the iPlan radiotherapy planning software. To determine the independent predictors of nidus volume reduction and perilesional brain edema (PBE), we performed multivariate Cox regression analysis to calculate hazard ratios. Twenty patients with 31 non-brainstem CCMs were enrolled in this study. Analysis revealed age as an independent predictive factor for both nidus volume reduction and PBE after radiation treatment for CCM. Furthermore, a single fraction dose of 17 Gy or more was identified as an independent predictor of nidus volume decrease, while a single fraction dose of 18 Gy or more was found to be an independent risk factor for PBE in patients with CCM following LINAC-based radiation therapy. LINAC-based radiation therapy for non-brainstem CCMs with a single fraction radiation dose between 16.5 and 17.5 Gy, or a biologically equivalent dose of approximately 120 Gy, may be the most effective at reducing nidus volume and limiting side effects, particularly in patients under the age of 55 years. We further observed that the risk of PBE increased as the maximum radiation dose delivered to a 1 cc volume of the surrounding normal brain exceeded approximately 17.3 Gy. Therefore, we believe that calculating the D1cc of the normal brain may help to predict the occurrence of PBE when radiotherapy is administered to non-brainstem CCMs.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

REGISTRATION

URL: https://www.chictr.org.cn/; Unique identifier: ChiCTR2300070907.

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

BACKGROUND

Brainstem 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.

METHODS

In 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.

RESULTS

The 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.

CONCLUSIONS

This 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.

Infratentorial Cerebral Cavernous Malformation May be a Risk Factor for Symptomatic Bleeding and Precocity of Symptoms: A Multicenter, Propensity Score Matched, Case-Control Study

BACKGROUND

Cerebral Cavernous Malformation (CCM) is one of the most common types of vascular malformation of the central nervous system. Intracerebral hemorrhage, seizures, and lesional growth are the main clinical manifestations. Natural history studies have tried to identify many risk factors; however, the clinical course remains highly unpredictable.

OBJECTIVE

Here, we have analyzed a multicenter CCM cohort looking for the differential clinical data regarding the patients harboring supra and/or infratentorial cavernous malformations in order to better understand risk factors involved in the anatomical location of the unique neurosurgical disease.

METHODS

We have presented a multicenter, Propensity Score Matched (PSM), case-control study including 149 consecutive CCM cases clinically evaluated from May 2017 to December 2022 from three different neurosurgical centers. Epidemiological data were defined at each clinical assessment. Logistic regression was used to identify the independent contribution of each possible risk factor to the bleeding risk. To balance baseline covariates between patients with and without symptoms, and specifically between those with and without symptomatic bleeding, we used a PSM strategy. The Kaplan-Meier curve was drawn to evaluate if patients with infratentorial lesions had a greater chance of bleeding earlier in their life.

RESULTS

The presence of infratentorial lesions was a risk factor in the multivariate analysis comparing the bleeding risk with pure asymptomatic individuals (OR: 3.23, 95% CI 1.43 - 7.26, P = 0.005). Also, having an infratentorial CCM was a risk factor after PSM (OR: 4.56, 95% CI 1.47 - 14.10, P = 0.008). The presence of an infratentorial lesion was related to precocity of symptoms when the time to first bleed was compared to all other clinical presentations in the overall cohort (P = 0.0328) and in the PSM group (P = 0.03).

CONCLUSION

Here, we have provided some evidence that infratentorial cerebral cavernous malformation may have a more aggressive clinical course, being a risk factor for symptomatic haemorrhage and precocity of bleeding.

Peritrigeminal Safe Entry Zone Access to Anterolateral Pons Using the Presigmoid Retrolabyrinthine Suprameatal Approach: A Cadaveric Morphometric Study

BACKGROUND AND OBJECTIVES

Access to the anterolateral pontine lesions can be achieved through the peritrigeminal and supratrigeminal safe entry zones using Kawase, retrosigmoid, or translabyrinthine approaches. However, these approaches entail shallow extensive dissection, tangential access, and compromise vestibulocochlear function. We aimed to investigate infratentorial presigmoid retrolabyrinthine approach to access pontine lesions through the peritrigeminal zone.

METHODS

We performed 10 presigmoid retrolabyrinthine suprameatal approach dissections in 5 cadaveric heads. Anatomic-radiological characteristics and variations were evaluated. Six morphometric parameters were measured and analyzed to predict surgical accessibility.

RESULTS

The pontine infratrigeminal area was accessible in all patients. The mean exposed area of the anterolateral pontine surface was 98.95 cm 2 (±38.11 cm 2 ). The mean length of the exposed trigeminal nerve was 7.9 cm (±2.9 cm). Preoperative anatomic-radiological parameters may allow to select patients with favorable anatomy that offers appropriate surgical accessibility to the anterior pontine cavernoma through a presigmoid retrolabyrinthine corridor.

CONCLUSION

Anterolateral pontine lesions can be accessed through a minimally invasive infratentorial presigmoid retrolabyrinthine approach by targeting the infratrigeminal safe entry zone. Further clinical studies should be conducted to evaluate the viability of this technique for treating these complex pathologies in real clinical settings.

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.

Approach Selection Strategies for Repeat Resection of Brain Cavernous Malformations: Cohort Study

BACKGROUND

Neurosurgical management of cerebral cavernous malformations (CMs) often benefits from using skull base approaches. Although many CMs are cured by resection, residual or recurrent disease may require repeat resection.

OBJECTIVE

To review approach selection strategies for reoperation of CMs to aid decision-making for repeat procedures.

METHODS

In this retrospective cohort study, a prospectively maintained single-surgeon registry was queried for patients with CMs who underwent repeat resection from January 1, 1997, to April 30, 2021.

RESULTS

Of 854 consecutive patients, 68 (8%) underwent 2 operations; 40 had accessible data on both. In most reoperations (33/40 [83%]), the index approach was repeated. In most reoperations using the index approach (29/33 [88%]), that approach was deemed ideal (no equivalent or superior alternative), whereas in some (4/33 [12%]), the alternative approach was deemed unsafe because of conformation of the tract. Among patients with reoperations using an alternative approach (7/40 [18%]), 2 with index transsylvian approaches underwent bifrontal transcallosal approaches, 2 with index presigmoid approaches underwent extended retrosigmoid revisions, and 3 with index supracerebellar-infratentorial approaches underwent alternative supracerebellar-infratentorial trajectory revisions. Among patients with reoperations with an alternative approach considered or selected (11/40 [28%]), 8 of 11 patients had a different surgeon for the index resection than for the repeat resection. The extended retrosigmoid-based approaches were used most often for reoperations.

CONCLUSION

Repeat resection of recurrent or residual CMs is a challenging neurosurgical niche at the intersection of cerebrovascular and skull base disciplines. Suboptimal index approaches may limit surgical options for repeat resection.

Cerebral cavernous malformation: Management, outcomes, and surveillance strategies - A single centre retrospective cohort study

BACKGROUND

Cerebral cavernous malformations (CCM) may undergo a period of clinical and/or radiographical surveillance that precedes or follows definitive treatment. There are no international guidelines on the optimal surveillance strategy. This study describes the surveillance strategies at our centre and explore the related clinical outcomes.

METHODS

We performed a retrospective study of adult patients with CCMs referred to a neurovascular service over an 8-year period, to determine the frequency and type of surveillance, intervention, and explore the associated outcomes. We report our findings adhering to STROBE guidelines.

RESULTS

133 patients (Male:Female 73:60; men age 42 years; range 12-82) were included. CCMs were identified in patients first presenting with symptomatic intracerebral haemorrhage (42.11%); headache, focal neurological deficit, or seizure without haemorrhage (41.35%); or, as an incidental finding (16.54%). The most common CCM location was supratentorial (59.40%), followed by brain stem (21.80%), cerebellum (10.53%) and basal ganglia (6.02%). Of the 133 patients, 77 patients (57.89%) were managed conservatively, 49 patients (36.84%) were managed by surgical resection alone, and seven patients (5.26%) were managed with stereotactic radiosurgery (SRS). Patients follow-up had a mean duration of 65.94 months, and varied widely (SD = 52.59; range 0-265), for a total of 730.83 person-years of follow up. During surveillance, 16 patients suffered an ICH equating to a bleeding rate of 2.19 per 100 patient years. CCMs that increased in size had a higher bleeding rate (p = 8.58 ×10^-4). There were 8 (6.02%) cases where routine clinic review or MRI resulted in a change in management.

CONCLUSIONS

Our single centre retrospective study supports existing literature relating to presentation and sequalae of CCM, with an increase in CCM size being associated with higher rates of detected bleeding. There remains heterogeneity, even within a single centre, on the frequency and modality of surveillance. Further, there are no international guidelines or high-quality data that recommends the optimal duration and frequency of surveillance, and its effect on clinical outcomes. This is a future research direction.

Radiosurgery effects and adverse effects in symptomatic eloquent brain-located Cavernomas

In this study, the dose schedule efficacy, safety and late adverse effects of stereotactic radiosurgery (SRS) were evaluated for patients with symptomatic cavernomas who were not eligible for surgery and treated with SRS. Between January 2013 and December 2018, 53 patients with cavernomas were treated using SRS with the CyberKnife® system. Patients' diseases were deeply located or were in subcortical functional brain regions. In addition to bleeding, 23 (43.4%) patients had epilepsy, 12 (22.6%) had neurologic symptoms and 16 patients (30.2%) had severe headaches. The median volume was 741 (range, 421-1351) mm3, and the median dose was 15 (range, 14-16) Gy in one fraction. After treatment, six (50%) of 12 patients with neurologic deficits still had deficits. Rebleeding after treatment developed in only two (3.8%) patients. The drug was completely stopped in 14 (60.9%) out of 23 patients who received epilepsy treatment, and the dose of levetiracetam decreased from 2000 mg to 1000 mg in four (17.3%) of nine patients. Radiologically, complete response (CR) was observed in 13 (24.5%) patients, and partial responses (PR) were observed in 32 (60.2%) patients. Clinical response of CR was observed in 30 (56.6%) patients, PR was observed in 16 (30.2%), stable disease (SD) was observed in three (5.7%) and four (7.5%) patients progressed. In conclusion, SRS applied in the appropriate dose schedule may be an effective and reliable method in terms of symptom control and prevention of rebleeding, especially in patients with inoperable cavernomas.

Residual and Recurrent Spinal Cord Cavernous Malformations: Outcomes and Techniques to Optimize Resection and a Systematic Review of the Literature

BACKGROUND

Intramedullary spinal cord cavernous malformations (SCCMs) account for only 5% of overall cavernous malformations (CMs). The occurrence of recurrent or residual SCCMs has not been well discussed, nor have the technical nuances of resection.

OBJECTIVE

To assess the characteristics of residual SCCMs and surgical outcomes and describe the techniques to avoid leaving lesion remnants during primary resection.

METHODS

Demographic, radiologic, intraoperative findings and surgical outcomes data for a cohort of surgically managed intramedullary SCCMs were obtained from an institutional database and retrospectively analyzed. A systematic literature review was performed using PRISMA guidelines.

RESULTS

Of 146 SCCM resections identified, 17 were for residual lesions (12%). Patients with residuals included 13 men and 4 women, with a mean age of 43 years (range 16-70). All patients with residual SCCMs had symptomatic presentations: sensory deficits, paraparesis, spasticity, and pain. Residuals occurred between 3 and 264 months after initial resection. Approaches for 136 cases included posterior midline myelotomy (28.7%, n = 39), pial surface entry (37.5%, n = 51), dorsal root entry zone (27.9%, n = 38), and lateral entry (5.9%, n = 8). Follow-up outcomes were similar for patients with primary and residual lesions, with the majority having no change in modified Rankin Scale score (63% [59/93] vs 75% [9/12], respectively, P = .98).

CONCLUSION

SCCMs may cause significant symptoms. During primary resection, care should be taken to avoid leaving residual lesion remnants, which can lead to future hemorrhagic events and neurological morbidity. However, satisfactory results are achievable even with secondary or tertiary resections.

Overview of the microanatomy of the human brainstem in relation to the safe entry zones

OBJECTIVE

The primary objective of this anatomical study was to apply innovative imaging techniques to increase understanding of the microanatomical structures of the brainstem related to safe entry zones. The authors hypothesized that such a high-detail overview would enhance neurosurgeons' abilities to approach and define anatomical safe entry zones for use with microsurgical resection techniques for intrinsic brainstem lesions.

METHODS

The brainstems of 13 cadavers were studied with polarized light imaging (PLI) and 11.7-T MRI. The brainstem was divided into 3 compartments-mesencephalon, pons, and medulla-for evaluation with MRI. Tissue was further sectioned to 100 μm with a microtome. MATLAB was used for further data processing. Segmentation of the internal structures of the brainstem was performed with the BigBrain database.

RESULTS

Thirteen entry zones were reported and assessed for their safety, including the anterior mesencephalic zone, lateral mesencephalic sulcus, interpeduncular zone, intercollicular region, supratrigeminal zone, peritrigeminal zone, lateral pontine zone, median sulcus, infracollicular zone, supracollicular zone, olivary zone, lateral medullary zone, and anterolateral sulcus. The microanatomy, safety, and approaches are discussed.

CONCLUSIONS

PLI and 11.7-T MRI data show that a neurosurgeon possibly does not need to consider the microanatomical structures that would not be visible on conventional MRI and tractography when entering the mentioned safe entry zones. However, the detailed anatomical images may help neurosurgeons increase their understanding of the internal architecture of the human brainstem, which in turn could lead to safer neurosurgical intervention.

Long-term outcomes after surgery for brainstem cavernous malformations: analysis of 46 consecutive cases

OBJECTIVE

The objective of this study was to evaluate the long-term outcomes after resection of brainstem cavernous malformations (BSCMs) and to assess the usefulness of the Lawton grading system in these cases.

METHODS

This retrospective study analyzed 46 consecutive patients with BSCMs operated on between July 1990 and December 2020. Outcomes at the last follow-up were defined as favorable (modified Rankin Scale [mRS] score 0-2) or unfavorable (mRS score > 2).

RESULTS

The study cohort comprised 24 men (52%) and 22 women (48%), ranging in age from 8 to 78 years old (median 37 years). In 19 patients (41%), the preoperative mRS score was > 2. All patients had hemorrhagic BSCM. There were 12 (26%) mesencephalic, 19 (41%) pontine, 7 (15%) medullary, and 8 (17%) cerebellar peduncle lesions, with a maximal diameter ranging from 5 to 40 mm (median 15 mm). In total, 24 BSCMs (52%) had bilateral extension crossing the brainstem midline. Lawton grades of 0, I, II, III, IV, V, and VI were defined in 3 (7%), 2 (4%), 10 (22%), 11 (24%), 8 (17%), 7 (15%), and 5 (11%) cases, respectively. Total resection of BSCMs was attained in 43 patients (93%). There were no perioperative deaths. Excluding the 3 most recent cases, the length of follow-up ranged from 56 to 365 months. The majority of patients demonstrated good functional recovery, but regress of the preexisting oculomotor nerve deficit was usually incomplete. No new hemorrhagic events were noted after total resection of BSCMs. In 42 patients (91%), the mRS score at the time of last follow-up was ≤ 2 (favorable outcome), and in 18 (39%), it was 0 (absence of neurological symptoms). Forty-four patients (96%) demonstrated clinical improvement and 2 (4%) had no changes compared with the preoperative period. Multivariate analysis revealed that only lower Lawton grade had a statistically significant independent association (p = 0.0280) with favorable long-term outcome. The area under the receiver operating characteristic curve for prediction of favorable outcome with 7 available Lawton grades of BSCM was 0.93.

CONCLUSIONS

Resection of hemorrhagic BSCMs by an experienced neurosurgeon may be performed safely and effectively, even in severely disabled patients. In the authors' experience, preexisting oculomotor nerve palsy represents the main cause of permanent postoperative neurological morbidity. The Lawton grading system effectively predicts long-term outcome after surgery.

Pediatric brainstem cavernous malformations: 2-center experience in 40 children

OBJECTIVE

Brainstem cavernous malformations (BSCMs) are relatively uncommon, low-flow vascular lesions in children. Given the paucity of data, guidelines regarding the clinical management of BSCMs in children are lacking and the surgical indication is most commonly based on an individual surgeon's judgment and experience. The goal in this study was to evaluate the clinical behavior of BSCMs in childhood and the long-term outcome in children managed conservatively and surgically.

METHODS

This was an observational, retrospective study including all children with BSCMs who were followed at 2 institutions between 2008 and 2020.

RESULTS

The study population consisted of 40 children (27 boys, 67.5%) with a mean age of 11.4 years. Twenty-three children (57.5%) were managed conservatively, whereas 17 children (42.5%) underwent resection of BSCMs. An aggressive clinical course was observed in 13 children (32.5%), who experienced multiple hemorrhages with a progressive pattern of neurological decline. Multiple BSCMs were observed in 8 patients, of whom 3 patients presented with a complex of multiple tightly attached BSCMs and posed a significant therapeutic challenge. The overall long-term outcome was favorable (modified Rankin Scale [mRS] scores 0-2) in 36 patients (90%), whereas an unfavorable outcome (mRS scores 3 and 4) was seen in 4 children (10%). An mRS score of 5 or 6 was not observed. The mean (± SD) follow-up was 88.0 (± 92.6) months.

CONCLUSIONS

The clinical course of BSCMs in children is highly variable, with benign lesions on the one hand and highly aggressive lesions with repetitive hemorrhages on the other. Given the greater life expectancy and the known higher functional recovery in children, surgical treatment should be considered early in young patients presenting with surgically accessible lesions and an aggressive clinical course, and it should be performed in a high-volume center.

Five-year symptomatic hemorrhage risk of untreated brainstem cavernous malformations in a prospective cohort

Hemorrhage of brainstem cavernous malformation (CM) would cause various symptoms and severe disability. The study aimed to elaborate on the 5-year actuarial cumulative hazard of symptomatic hemorrhage. Patients diagnosed in our institute between 2009 and 2013 were prospectively registered. All clinical data were obtained, follow-up was performed, and risk factors were evaluated. Four hundred sixty-eight patients (217 female, 46.4%) were included in the study with a median follow-up duration of 79.0 months. A total of 137 prospective hemorrhages occurred in 107 patients (22.9%) during 1854.0 patient-years. Multivariate Cox analysis found age ≥ 55 years (hazard ratio (HR) 2.166, p = 0.002), DVA (HR 1.576, p = 0.026), superficial-seated location (HR 1.530, p = 0.047), and hemorrhage on admission (HR 2.419, p = 0.026) as independent risk factors for hemorrhage. The 5-year cumulative hazard of hemorrhage was 30.8% for the overall cohort, 47.8% for 60 patients with age ≥ 55 years, 43.7% for 146 patients with DVA, 37.9% for 272 patients with superficial-seated lesions, and 37.2% for 341 patients with hemorrhage on admission. As a stratified analysis, within subcohort of 341 patients with a hemorrhagic presentation, age ≥ 55 years (HR 3.005, p < 0.001), DVA (HR 1.801, p = 0.010), and superficial-seated location (HR 2.276, p = 0.001) remained independently significant. The 5-year cumulative hazard of hemorrhage was 52.0% for 119 patients with both DVA and hemorrhagic presentation. The 5-year cumulative hemorrhagic risk was 30.8% and was higher in subgroups if harboring risk factors that helped to predict potential hemorrhagic candidates and were useful for treatment decision-making.Clinical Trial Registration-URL: http://www.chictr.org.cn Unique identifier: ChiCTR-POC-17011575.

Tailored Treatment Options for Cerebral Cavernous Malformations

The diagnosis and treatment of cerebral cavernous malformations (CCMs), or cavernomas, continues to evolve as more data and treatment modalities become available. Intervention is necessary when a lesion causes symptomatic neurologic deficits, seizures, or has high risk of continued hemorrhage. Future medical treatment directions may specifically target the pathogenesis of these lesions. This review highlights the importance of individualized treatment plans based on specific CCM characteristics.

Endoscope-assisted resection of brainstem cavernous malformations

Targeted surgical precision and minimally invasive techniques are of utmost importance for resectioning cavernous malformations involving the brainstem region. Minimisation of the surgical corridor is desirable but should not compromise the extent of resection. This study provides detailed information on the role of endoscopy in this challenging surgical task. A retrospective analysis of medical documentation, radiologic studies and detailed intraoperative video documentation was performed for all consecutive patients who underwent surgical resection of brainstem cavernous malformations between 2010 and 2020 at the authors’ institution. A case-based volumetry of the corticotomy was performed and compared to cavernoma dimensions. A total of 20 procedures have been performed in 19 patients. Neuroendoscopy was implemented in all cases. The mean size of the lesion was 5.4 (± 5) mm3. The average size of the brainstem corticotomy was 4.5 × 3.7 (± 1.0 × 1.1) mm, with a median relation to the cavernoma’s dimension of 9.99% (1.2–31.39%). Endoscopic 360° inspection of the resection cavity was feasible in all cases. There were no endoscopy-related complications. Mean follow-up was 27.8 (12–89) months. Gross-total resection was achieved in all but one case (95%). Sixteen procedures (80%) resulted in an improved or stable medical condition. Eleven patients (61.1%) showed further improvement 12 months after the initial surgery. With the experience provided, endoscopic techniques can be safely implemented in surgery for BSCM. A combination of neuroendoscopic visualisation and neuronavigation might enable a targeted size of brainstem corticotomy. Endoscopy can currently be considered a valuable additive tool to facilitate the preparation and resection of BSCM.

Surgical treatment of brainstem cavernous malformations: an international Delphi consensus

OBJECTIVE

Indication for surgery in brainstem cavernous malformations (BSCMs) is based on many case series, few comparative studies, and no randomized controlled trials. The objective of this study was to seek consensus about surgical management aspects of BSCM.

METHODS

A total of 29 experts were invited to participate in a multistep Delphi consensus process on the surgical treatment of BSCM.

RESULTS

Twenty-two (76%) of 29 experts participated in the consensus. Qualitative analysis (content analysis) of an initial open-ended question survey resulted in 99 statements regarding surgical treatment of BSCM. By using a multistep survey with 100% participation in each round, consensus was reached on 52 (53%) of 99 statements. These were grouped into 4 categories: 1) definitions and reporting standards (7/14, 50%); 2) general and patient-related aspects (11/16, 69%); 3) anatomical-, timing of surgery-, and BSCM-related aspects (22/37, 59%); and 4) clinical situation-based decision-making (12/32, 38%). Among other things, a consensus was reached for surgical timing, handling of associated developmental venous anomalies, handling of postoperative BSCM remnants, assessment of specific anatomical BSCM localizations, and treatment decisions in typical clinical BSCM scenarios.

CONCLUSIONS

A summary of typical clinical scenarios and a catalog of various BSCM- and patient-related aspects that influence the surgical treatment decision have been defined, rated, and interpreted.

Resection of Brainstem Cavernous Malformations: Pearls and Pitfalls for Minimizing Complications

BACKGROUND

Surgical management of brainstem cavernous malformations (CMs) is a controversial topic in the field of neurosurgery. These lesions have a propensity to hemorrhage, thereby disrupting surrounding brainstem eloquence.

METHODS

This article provides the personal reflections of the senior author and a narrative literature review on resection of brainstem CMs.

RESULTS

Here we discuss the indications for microsurgery, microsurgical techniques and nuances, and perioperative management considerations necessary to minimize complications during resection of brainstem CMs, which are lesions of venous origin.

CONCLUSIONS

The natural history of the lesion, risk of future hemorrhage, and potential for symptom resolution should be carefully considered when planning to resect brainstem CMs. Nuanced microsurgical techniques with minimal disruption of normal tissues provide the best chance of satisfactory outcomes.

How I do it: horizontal fissure approach to the middle cerebellar peduncle

BACKGROUND

The horizontal fissure approach is a workhorse for brainstem lesions in the central and dorsolateral pons and middle cerebellar peduncle (MCP). The cerebellopontine fissure is a V-shaped fissure with a superior and inferior limb between the cerebellum, pons, and MCP. The horizontal or petrosal fissure is at the apex of the cerebellopontine fissure and extends laterally to divide the petrosal surface of the cerebellum into superior and inferior parts. Splitting this fissure exposes the posterolateral aspect of the MCP without excessive retraction or transgression of the cerebellum.

METHOD

We demonstrate and describe the horizontal fissure operative approach to the middle cerebellar peduncle for resection of a pontine cavernoma with illustrative figures and operative video.

CONCLUSION

Splitting the horizontal (petrosal) fissure of the cerebellum brings the middle cerebellar peduncle into view behind the root entry zone of the trigeminal nerve, providing an expanded, safe corridor to the central and dorsolateral pons.

Brainstem Cavernous Malformations Management: Microsurgery vs. Radiosurgery, a Meta-Analysis

Given the rareness of available data, we performed a systematic review and meta-analysis on therapeutic strategy microsurgical resection and stereotactic radiosurgery (SRS) for brainstem cavernous malformations (BSCMs) and assessed mortality, permanent neurological deficits (PNDs), rebleeding rate, and patients who require reintervention to elucidate the benefits of each treatment modality. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) were used for protocol development and manuscript preparation. After applying all inclusion and exclusion criteria, six remaining articles were included in the final manuscript pool. In total, this meta-analysis included 396 patients, among them 168 patients underwent microsurgical treatment and 228 underwent SRS. Findings of the present meta-analysis suggest that regarding the total group of patients, in terms of mortality, late rebleeding rate, and PNDs, there was no superiority of the one method over the other. Applying the leave-one-out method to our study suggests that with low robust of the results for the bleeding rate and patients who require reintervention outcome factor, there was no statistical difference among the surgical and SRS treatment. Microsurgical treatment of BSCMs immediately eliminates the risk of rehemorrhage; however, it requires complete excision of the lesion and it is associated with a similar rate of PNDs compared with SRS management. Apparently, SRS of BSCMs causes a marked reduction in the risk of rebleeding 2 years after treatment, but when compared with the surgical treatment, there was not any remarkable difference.

The occurrence of neuropathic pain following surgery of brainstem cavernous malformations

BACKGROUND AND PURPOSE

This study aimed to assess the occurrence and significance of postoperative neuropathic pain (NP) in patients with surgically treated brainstem cavernous malformations (BSCMs).

METHODS

Seventy-four BSCM patients surgically treated between 2003 and 2019 were reviewed for the occurrence of postoperative NP and related treatment. The relevance of BSCM location, preoperative characteristics, influence on functional outcome, postoperative health-related quality of life (HRQOL) and life satisfaction was evaluated.

RESULTS

Six out of 74 patients (8%) suffered from NP. The Leeds Assessment of Neuropathic Symptoms and Signs scores ranged from 12 to 16 (mean 14.28 ± 1.6). Visual analog scale pain was 5.2 ± 2.0. NP had no effect on preoperative characteristics or functional outcome. Bodily pain (HRQOL) and vocational time (life satisfaction) were significantly decreased in NP compared to non-NP patients. Specific BSCM location (regarding brainstem nuclei involved in pain processing) and other preoperative patient- and BSCM-related parameters were not associated with the occurrence of postoperative NP. Three out of six patients were currently under NP-specific treatment. The proportion of patients suffering from postoperative NP (8%) was substantially higher compared to previously published studies. The pain affected the HRQOL of patients, most of whom were insufficiently treated and not satisfied with treatment results.

CONCLUSION

Our findings may help to raise awareness for postoperative NP in BSCM, which is essential to improve diagnosis and initiation of proper treatment, as well as preoperative informed consent of patients.

The BSCM score: a guideline for surgical decision-making for brainstem cavernous malformations

Microsurgical resection of brainstem cavernous malformations (BSCMs) can be performed today with acceptable morbidity and mortality. However, in this highly eloquent location, the indication for surgery remains challenging. We aimed to elaborate a score system that may help clinicians with their choice of treatment in patients with BSCMs in this study. A single-center series of 88 consecutive BSCMs patients with 272 follow-up visits were included in this study. Univariable and multivariable generalized estimating equations (GEE) were constructed to identify the association of variables with treatment decisions. A score scale assigned points for variables that significantly contributed to surgical decision-making. Surgical treatment was recommended in 37 instances, while conservative treatment was proposed in 235 instances. The mean follow-up duration was 50.4 months, and the mean age at decision-making was 45.9 years. The mean BSCMs size was 14.3 ml. In the multivariable GEE model, patient age, lesion size, hemorrhagic event(s), mRS, and axial location were identified as significant factors for determining treatment options. With this proposed score scale (grades 0–XII), non-surgery was the first option at grades 0–III. The crossover point between surgery and non-surgery recommendations lay between grades V and VI while surgical treatment was found in favor at grades VII–X. In conclusion, the proposed BSCM operating score is a clinician-friendly tool, which may help neurosurgeons decide on the treatment for patients with BSCMs.

Novel Approach to Medullary Oblongata Cavernous Hemangioma

We report the case of a 31-year-old male patient who presented with complaints of left upper and lower limb weakness with giddiness, imbalance while walking, hiccups, nasal regurgitation, and history of difficulty in swallowing. He was evaluated and diagnosed to have a space-occupying lesion in the left medulla oblongata-cavernous hemangioma. He underwent suboccipital craniotomy and excision of the lesion. Postoperatively, he regained strength and balance. He is asymptomatic during follow-up.

Natural History of Brainstem Cavernous Malformations: On the Variation in Hemorrhage Rates

BACKGROUND

Hemorrhage rates of conservatively managed brainstem cavernous malformations (BSCMs) vary widely in the literature. We aimed to elucidate the reason for the variation and to add the results of our experience of BSCMs management over the past decade.

METHODS

We performed a review of consecutive patients with BSCMs referred to our department in the period 2006-2018. A hemorrhagic event was defined as a radiographically verified intralesional and extralesional hemorrhage. Both retrospective and prospective hemorrhage rates were calculated based on the patient age in years, counted either from birth or from the time of initial presentation until the last contact (or until surgical resection). In addition, we retrieved and reviewed publications with a clear definition of hemorrhagic event and a detailed description of BSCM hemorrhage rate.

RESULTS

In total, 118 patients with BSCMs were reviewed, and 78 patients (mean age on admission 45.9 years) were included in the final analysis. The retrospective and prospective hemorrhage rates were 1.9% (95% confidence interval 1.6%-2.3%) per year and 11.9% (95% confidence interval 7.5%-17.8%), respectively. The retrospective hemorrhage rate in the literature review ranged from 1.9% to 6.8% per year with a median value of 3.8%, whereas the prospective hemorrhage rate ranged between 4.1% and 21.5%, with a median value of 10.2%.

CONCLUSIONS

The reported hemorrhage rates are calculated in 2 different ways. In our patient cohort, both the retrospective and prospective hemorrhage rates were in accordance with those in the literature. The long-term hemorrhage rate lies between the prospective and retrospective rate.

The benefit and outcome prediction of acute surgery for hemorrhagic brainstem cavernous malformation with impending respiratory failure

OBJECTIVES

Impending respiratory failure is catastrophic neurological deterioration caused by repeated c of a brainstem cavernous malformation (BSCM). The benefit and outcome prediction of acute surgery for this fatal condition is rarely reported. In this study, the authors reported a case series of acute surgical treatment (≤3 weeks after the last hemorrhagic episode) for the BSCM with impending respiratory failure and reviewed literature over the past 20 years.

MATERIALS AND METHODS

Clinical and outcome data from 6 consecutive acute surgically-treated BSCM patients were analyzed. Intracerebral hemorrhage (ICH) scores, primary pontine hemorrhage (PPH) scores, and Lawton's BSCM grading were applied for surgical outcome prediction. Ten related articles were included for the literature review.

RESULTS

There were three men and three women, with a mean age of 32.2 ± 9.3 years (range 15-45 years). The BSCMs were located at the pons in 5 cases and the medulla in 1 case. The ICH score was 1-2 in all cases, while the PPH score was 0 in all pontine BSCMs. For Lawton's BSCM grading, 3 cases were grade 2, 2 cases were grade 3, and 1 case was grade 1. All patients achieved spontaneous respiratory dysfunction relief postoperatively and significantly improved at follow-up (mean 4.47 ± 0.24 years;range4.0-5.6 years).

CONCLUSIONS

Repeated hemorrhagic BSCM with impending respiratory failure can benefit from acute surgical treatment. The ICH score, PPH score, and Lawton's BSCM grading are promisingly useful tools for fast and efficient surgical outcome prediction.

Microsurgical management of midbrain cavernous malformations: does lesion depth influence the outcome?

Background

The purpose of this study was to clarify whether the intrinsic depth of midbrain cavernous malformations (MCMs) influenced the surgical outcome.

Methods

The authors conducted a retrospective study of 76 consecutive patients who underwent microsurgical resection of a MCM. The vascular lesions were categorized into 4 distinct groups based on how these lesions had altered the brainstem surface. Additionally, it was verified whether the actual aspect of the brainstem surface could be predicted only by evaluating the pertinent preoperative MRI slices. Clinical outcome was assessed by determining the modified Rankin Scale Score (mRS) before and after surgery.

Results

Twenty-three MCMs (30.3%) were located deeply within the midbrain. The overlying midbrain surface appeared to be normal (group nl). In 33 patients (43.4%), the midbrain surface showed only a yellowish discoloration (group yw). In another 14 individuals (18.4%), the midbrain surface was distorted by the underlying MCM and bulging out while the vascular lesion still remained covered by a thin parenchymal layer (group bg). In the smallest group comprising 6 patients (7.9%), the exophytic MCM had disrupted the midbrain surface and was clearly visible at microsurgical exposure (group ex). The mean mRS decreased in the group nl from 1.43 preoperatively to 0.61 at follow-up.

Conclusion

This study demonstrates in a large patient population that a deep intrinsic MCM location is not necessarily associated with an unfavorable clinical outcome after microsurgical lesionectomy. Predicting the aspect of the midbrain surface by evaluating preoperative MR images alone was not sufficiently reliable.

Recurrent brainstem cavernous malformations following primary resection: blind spots, fine lines, and the right-angle method

OBJECTIVE

Proximity of brainstem cavernous malformations (BSCMs) to tracts and cranial nerve nuclei make it costly to transgress normal tissue in accessing the lesion or disrupting normal tissue adjacent to the lesion in the separation plane. This interplay between tissue sensitivity and extreme eloquence makes it difficult to avoid leaving a remnant on occasion. Recurrences require operative intervention, which may increase morbidity, lengthen recovery, and add to overall costs. An approximately 20-year experience with patients with recurrent BSCM lesions following primary microsurgical resection was reviewed.

METHODS

A prospectively maintained database of 802 patients who underwent microsurgical resection of cerebral cavernous malformations during 1997-2018 was queried to identify 213 patients with BSCMs. A retrospective chart review was conducted for patients with recurrent BSCM after primary resection who required a second surgery.

RESULTS

Fourteen of 213 patients (6.6%) underwent repeat resection for recurrent BSCM. Thirty-four hemorrhagic events were observed among these 14 patients over 576 patient-years (recurrent hemorrhage rate, 5.9% per year; median discrete hemorrhagic events, 2; median time to rehemorrhage, 897 days). BSCM occurred in the pons in 10 cases, midbrain in 2 cases, and medulla in 2 cases. A blind spot in the operative corridor was the most common cause of residual BSCM (9 patients). All recurrent BSCMs were removed completely, although 2 patients each required 2 operations to treat recurrence. Twelve patients had unchanged or improved modified Rankin Scale scores at last clinical evaluation compared with admission, and 2 patients had worse scores. Recurrence was more common among patients who were operated on in the first versus the second half of the series (8.5% vs 4.7%).

CONCLUSIONS

The 6.6% rate of BSCM recurrence requiring reoperation reflects the fine lines between complete resection and recurrence and between safe and harmful surgery. The detection of remnants is difficult postoperatively and remains so even at 6 months when the resection bed has healed. The 5.9% annual hemorrhage risk associated with recurrent BSCM in this experience is consistent with that reported for unoperated BSCMs. The right-angle method helps to anticipate blind spots and meticulously inspect the resection cavity for residual BSCM during surgery. A low percentage of recurrent BSCM (5%-10%) ensures ongoing effort toward an acceptable balance of safety and completeness.

Holmes tremor: a delayed complication after resection of brainstem cavernomas

OBJECTIVE

In this paper, the authors aimed to illustrate how Holmes tremor (HT) can occur as a delayed complication after brainstem cavernoma resection despite strict adherence to the safe entry zones (SEZs).

METHODS

After operating on 2 patients with brainstem cavernoma at the Great Metropolitan Hospital Niguarda in Milan and noticing a similar pathological pattern postoperatively, the authors asked 10 different neurosurgery centers around the world to identify similar cases, and a total of 20 were gathered from among 1274 cases of brainstem cavernomas. They evaluated the tremor, cavernoma location, surgical approach, and SEZ for every case. For the 2 cases at their center, they also performed electromyographic and accelerometric recordings of the tremor and evaluated the post-operative tractographic representation of the neuronal pathways involved in the tremorigenesis. After gathering data on all 1274 brainstem cavernomas, they performed a statistical analysis to determine if the location of the cavernoma is a potential predicting factor for the onset of HT.

RESULTS

From the analysis of all 20 cases with HT, it emerged that this highly debilitating tremor can occur as a delayed complication in patients whose postoperative clinical course has been excellent and in whom surgical access has strictly adhered to the SEZs. Three of the patients were subsequently effectively treated with deep brain stimulation (DBS), which resulted in complete or almost complete tremor regression. From the statistical analysis of all 1274 brainstem cavernomas, it was determined that a cavernoma location in the midbrain was significantly associated with the onset of HT (p < 0.0005).

CONCLUSIONS

Despite strict adherence to SEZs, the use of intraoperative neurophysiological monitoring, and the immediate success of a resective surgery, HT, a severe neurological disorder, can occur as a delayed complication after resection of brainstem cavernomas. A cavernoma location in the midbrain is a significant predictive factor for the onset of HT. Further anatomical and neurophysiological studies will be necessary to find clues to prevent this complication.

Outcome of intracerebral cavernoma treated by Gamma Knife radiosurgery based on a double-blind assessment of treatment indication

BACKGROUND

The benefit and the risk profile of Gamma Knife radiosurgery (GKRS) for intracerebral cavernoma remains incompletely defined in part due to the natural history of low incidence of bleeding and spontaneous regression of this vascular malformation. In this study, we retrieved cases from a prospectively collected database to assess the outcome of intracerebral cavernoma treated with GKRS using a double blinded review process for treatment.

METHODS

From 2003 to 2018, there were 94 cases of cavernoma treated by GKRS in the doubly blinded assessments by two experienced neurological and approved for GKRS treatment. All the patients received GKRS with margin dose of 11-12 (Gray) Gy and afterwards were assessed for neurological outcome, radiologic response, and quality of life.

RESULTS

The median age of the patients was 48 (15-85) years with median follow up of 77 (26-180) months post SRS. The mean target volume was 1.93 ± 3.45 cc. In those who has pre-SRS epilepsy, 7 of 16 (43.7%) achieved seizure freedom (Engel I/II) and 9 of 16 (56.3%) achieved decreased seizures (Engel III) after SRS. Rebleeding occurred in 2 cases (2.1%) at 13 and 52 months post SRS. The radiologic assessment demonstrated 20 (21.3%) cases of decreased cavernoma volume, 69 (73.4%) were stable, and 5 (7.3%) increased size. Eighty-seven of 94 (92.5%) cases at the last follow up achieve improvement in their quality of life, but 7 cases (7.4%) showed a deterioration. In statistical analysis, the effective seizure control class (Engel I/II) was highly correlated with patient harboring a single lesion (p < 0.05) and deep seated location of the cavernoma (p < 0.01). New neurological deficits were highly correlated with decreased mental (p < 0.001) and physical (p < 0.05) components of quality of life testing, KPS (p < 0.001), deep seated location (p < 0.01), and increased nidus volume (p < 0.05). Quality of life deterioration either in physical component (p < 0.01), mental component (p < 0.01), and KPS (p < 0.05) was highly correlated with increased cavernoma volume.

CONCLUSION

Low margin dose GKRS for intracerebral cavernoma offers reasonable seizure control and improved quality of life while conferring a low risk of treatment complications including adverse radiation effect.

Multimodal outcome assessment after surgery for brainstem cavernous malformations

OBJECTIVE

The object of this study was to assess outcome after surgery for brainstem cavernous malformations (BSCMs) using functional, health-related quality of life (HRQOL), and psychological surveys to analyze the interrelation of these measurements, and to compare HRQOL and anxiety and depression scores with those in a healthy population.

METHODS

The authors performed a cross-sectional outcome study of all patients surgically treated for BSCM in their department between January 1, 2003, and December 31, 2019. They assessed functional outcome via the modified Rankin Scale (mRS), health-related quality of life (HRQOL) via the SF-36 and 9-item Life Satisfaction Questionnaire (LISAT-9), cranial nerve and brainstem function using a questionnaire, symptom-based psychological outcome via the Hospital Anxiety and Depression Scale (HADS), and timepoint of a return to previous employment. They analyzed the correlation between absolute (mRS score ≤ 2) and relative (postoperative deterioration in initial mRS score) outcome endpoints and the interrelation of the outcome measures and performed a comparison of HRQOL and HADS scores with findings in a healthy population.

RESULTS

Seventy-four patients were eligible for inclusion in the study. HRQOL was impaired after surgery for BSCM compared to that in a healthy population. This impairment was substantial in patients with an unfavorable functional outcome (mRS > 2) but was also present in those with a favorable outcome (mRS ≤ 2) in selected domains. Psychological impairment was negligible in patients with a favorable outcome and grave in those with an unfavorable outcome. LISAT-9 results revealed that brainstem and cranial nerve symptoms reduce satisfaction mainly in self-care abilities for both unfavorable and favorable outcome patients. Among the brainstem and cranial nerve symptoms, balance impairment showed the most significant impact on HRQOL. Absolute outcome endpoints were superior to relative outcome endpoints in reflecting impairment in HRQOL after surgery.

CONCLUSIONS

The study data can improve patient counseling and decision-making in BSCM treatment and may function as a benchmark. The authors report outcomes after BSCM surgery in high detail, emphasizing the specific impact of cranial nerve and brainstem symptoms on HRQOL. When reporting BSCM surgery outcome, absolute outcome endpoints should be applied.

Follow the Venous Path to the Hidden Lesion: A Technical Trick in Brainstem Cavernous Malformation Surgery

OBJECTIVE

Deep-seated brainstem cavernous malformations (BSCMs) pose a particular challenge for brainstem entry intraoperatively and their treatment can require comprehensive application of neuronavigation, electrophysiological brainstem mapping and monitoring, and full knowledge of safe brainstem entry zones. In the present report, we have introduced a supplementary technical trick for localizing a hidden tiny lesion inside the brainstem when a developmental venous anomaly (DVA) is present on the brainstem surface.

METHODS

A retrospective analysis of a 74-case cohort treated surgically from January 2011 to December 2019 was conducted. We identified 11 patients (14.9%) whose deep-seated BSCMs were exposed and removed following a brainstem surface DVA path as a supplementary technical trick. We have presented 2 typical cases to illustrate the operative nuances.

RESULTS

Of the 11 patients, 5 were male and 6 were female. Their average age was 38.0 ± 14.0 years (range, 15-62 years). Most BSCMs were located in the pons (n = 5; 45.5%), followed by the pontomesencephalic area (n = 3; 27.3%), midbrain (n = 2; 18.2%), and medulla oblongata (n = 1; 9.1%). All BSCMs were successfully located and completely removed. In 5 cases, the DVA was impaired after lesion removal (45.5%). However, no aggravated postoperative brainstem edema occurred in any of the 11 patients. After 3.6 ± 2.0 years of follow-up (2 patients were lost to follow-up; follow-up rate, 81.8%), no rebleeding was found, and the modified Rankin scale score of the patients had improved from 2.7 ± 1.1 preoperatively to 1.7 ± 0.9 at follow-up (P = 0.031).

CONCLUSIONS

The presented method could help surgeons trace deep-seated BSCMs with minimal brainstem parenchyma impairment, avoiding unnecessary aggressive exploration.

Resection of Pontine Cavernoma Through the Anterior Transpetrosal Approach: 2-Dimensional Operative Video

The pons is the most frequent local for brain stem cavernoma.1 Repeated hemorrhage of brainstem cavernoma is associated with significant and accumulative neurological deficits and thus requires treatment. According to the Swedish Karolinska's group of radiosurgery, "it could not be concluded whether GKRS affects the natural course of a CM. The incidence of radiation-induced complications was approximately seven times higher than that expected."2 Thus, microsurgical removal has become the mainstay of treatment. In our experience, the following details assist in obtaining favorable outcomes and avoiding postoperative complications3,4: (a) the entry into the cavernoma based on thorough knowledge of the microanatomy; (b) the detailed study of the images and the presentation of the cavernoma on or near the brain stem surface; (c) the resection of the live cavernous hemangioma and not the mere removal of the multiple aged organized hematomas; (d) the preservation of the associated venous angioma; (e) the direct and shortest access to the lesion provided by a skull base approach; and (f) the use of the available technology, such as intraoperative neuromonitoring and neuroimaging. We present the case of a 54-yr-old male with recent deterioration in year 2001, past repetitive episodes of gait imbalance, and speech difficulty over a 7-yr period from known pontine cavernoma. The anterior petrosal approach provided superb and direct exposure to the entry at the lateral pons and the cavernoma was totally removed with preservation of the venous angioma. His preoperative neurological deficit rapidly recovered. Patient consented to the procedure and photography. Images at 3:15 from Kadri et al, The anatomical basis for surgical presercation of temporal muscle. J Neurosurg. 2004;100:517-522, used with permission from JNSPG. Image at 3:27 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997, with permission.

Anterior transpetrosal resection of the lower ventral pontine cavernous malformation: A technical case report with operative video

Background

Surgical treatment of pontine cavernous malformations (CMs) is challenging due to the anatomical difficulties and potential risks involved. We successfully applied an anterior transpetrosal approach (ATPA) to remove a lower ventral pontine CM, and herein we discuss the outline of our procedure accompanied by a surgical video.

Case Description

A 50-year-old woman presenting with progressively worsening diplopia was urgently admitted to our hospital. Preoperative images showed a lower ventral pontine CM compressing the corticospinal tract posteriorly. Considering the location of the CM, we determined that an ATPA was the appropriate approach to achieve a more anterolateral trajectory. We performed extradural anteromedial petrosectomy and penetrated the brainstem from the point just below the anterior inferior cerebellar artery and above the root exit zone of the abducens nerve, which might be located in the somewhat lowest border of actual maneuverability in the ATPA. Maneuverability through this corridor was sufficient without hindering and darkening the high magnification microscopic view, as demonstrated in our surgical video.

Conclusion

This report demonstrates surgical treatment of a lower ventral pontine CM using the ATPA. The surgical video we present provides information that is useful for understanding this technique's maneuverability and working window.

Transcondylar Approach for Resection of Medullary Cavernous Malformation: 2-Dimensional Operative Video

Cavernous malformations located within the brainstem present with a high rate of neurological symptoms and carry a more aggressive course in both pediatric and adult populations.1,2 Cavernomas within the medulla are the rarest form, representing only 5% of all brainstem lesions.3 Repeated hemorrhage of brainstem cavernomas is associated with significant and cumulative neurological deficits and thus requires treatment.4 Microsurgical resection has become the optimal mode of treatment with the aim of resecting the live malformation and not merely the multiaged, organized hematoma.4 This is best achieved by approaching the cavernoma at the location where it projects to the surface and entering the lesion through a safe brainstem anatomic zone. For ventrally located lesions in the medulla, a transcondylar skull base approach provides a direct trajectory to the entry zone through a short surgical distance without the need to manipulate or retract neurovascular structures.5-8 Neuronavigation and intraoperative neurophysiological monitoring of somatosensory evoked potential, motor, and lower cranial nerves are adjuncts to increase patient safety. Radiosurgery for the treatment of brainstem cavernous malformations has been proposed; however, it demonstrates high risk and variable and often poor response rates.9 We present a surgical video demonstrating the transcondylar approach and resection of a medullary cavernoma in a 54-yr-old woman who has had multiple known prior hemorrhages and presented with a new onset of facial numbness and weakness, ataxia, and left body sensory loss. The patient consented to surgery and to photograph publication.  Images at 1:28, 1:43 (left), 2:02 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997,5 with permission.  Images at 1:43 (right) from Arnautovic et al,8 with permission from JNSPG.

Long-term outcome and quality of life after CNS cavernoma resection: eloquent vs. non-eloquent areas

The aim of this study is to analyze the long-term quality of life after surgery of cavernoma. A monocentric retrospective study was conducted on 69 patients with cavernoma treated microsurgically between 2000 and 2016. The eloquence was adopted from Spetzler-Martin definition. A most recent follow-up was elicited between 2017 and 2019, in which the quality of life (QoL) was evaluated with the Short Form-12 questionnaire (SF12). Forty-one lesions were in eloquent group (EG), 22 in non-eloquent group (NEG), 3 in orbit, and 3 in the spinal cord. Postoperative worsening of the modified Rankin scale (mRS) occurred in 19.5% of cases in EG versus 4.5% in NEG. After a mean follow-up of 6.5 years (SD 4.6), the neurological status was better or unchanged compared to baseline in 85.4% of EG and 100% of NEG. Regarding QoL assessment of 44 patients (EG n = 27, NEG n = 14) attended the last follow-up. Patients after eloquent cavernoma resection reported a non-inferior QoL in most SF12 domains (except for physical role) compared to NEG. However, they reported general health perception inferior to norms, which was affected by the limited physical and emotional roles. At a late follow-up, the surgical morbidity was transient in the NEG and mostly recovered in the EG. The QoL comparison between eloquent and non-eloquent cavernomas created interesting and new data after prolonged follow-up. These results add value for decision-making as well as patient counseling for future encountered cases. Preoperative evaluation of QoL is recommended for future studies to assess QoL dynamics.

Supracerebellar Infratentorial Infratrochlear Trans-Quadrangular Lobule Approach to Pontine Cavernous Malformations

BACKGROUND

Brainstem cavernous malformations with symptomatic hemorrhage have a poor natural history. Those without a pial or ependymal presentation are often observed given the morbidity of resection. Surgical removal is considered only in patients with accessible lesions that have repeated symptomatic hemorrhagic.

OBJECTIVE

To describe a novel supracerebellar infratentorial infratrochlear trans-quadrangular lobule approach to safely resect lesions in the upper pons.

METHODS

We use a hybrid paramedian/lateral suboccipital craniotomy in the gravity-dependent supine position. Opening the cerebellomesencephalic fissure over the tentorial surface of the cerebellum brings the trochlear nerve, branches of the superior cerebellar artery, and the quadrangular lobule of the cerebellum into view. Removal of small a portion of the quadrangular lobule defines an entry point on the superomedial aspect of the middle cerebellar peduncle, and a surgical trajectory aimed superior to inferior.

RESULTS

A total of 6 patients underwent this approach. All presented with symptomatic hemorrhage and all cavernous malformations were completely resected. Five patients were improved or unchanged with modified Rankin scale scores of 1 or 2.

CONCLUSION

The trans-quadrangular lobule approach allows safe resection of upper pontine cavernous malformations along a superior to inferior trajectory.

Endoscopic Endonasal Transclival Resection of a Pontine Metastasis: Case Report and Operative Video

BACKGROUND AND IMPORTANCE

Brainstem lesions are challenging to manage, and surgical options have been controversial. Stereotactic radiosurgery (SRS) has been used for local control, but life-threatening toxicities from 0% to 9.5% have been reported. Several microsurgical approaches involving safe entry zones have been developed to optimize the exposure and minimize complications in different portions of the brainstem, but require extensive drilling and manipulation of neurovascular structures. With recent advancements, the endoscopic endonasal approach (EEA) can provide direct visualization of ventral brainstem. No case has been reported of EEA to remove a brainstem metastasis.

CLINICAL PRESENTATION

We present an illustrative case of a 68-yr-old female with metastatic colon cancer who presented with 2.8 × 2.7 × 2.1 cm (7.9 cm3) heterogeneously enhancing, right ventral pontine lesion with extensive edema. She underwent endoscopic endonasal transclival approach, and gross total resection of the lesion was achieved.

CONCLUSION

The endoscopic approach may offer certain advantages for removal of ventral brainstem lesions, as it can provide direct visualization of important neurovascular structures, especially, if the lesion displaces the tracts and comes superficial to the pial surface.