The transcallosal transchoroidal approach to the diencephalic-mesencephalic junction: how I do it

BACKGROUND

Different approaches have to be considered for lesions of the diencephalic-mesencephalic junction based on the localization, extension of the lesion, and relationship to the ventricular system.

METHOD

We present the case of a young lady who presented with a cavernoma of the junction of midbrain and diencephalon after an episode of hemorrhage. The microsurgical anatomy of the trans-callosal trans-choroidal approach for this lesion is described along with its advantages and limitations.

CONCLUSION

The trans-choroidal approach allows adequate access to lesions of the diencephalic-mesencephalic junction that project into the third ventricle.

Left Interhemispheric Craniotomy for Resection of Cavernous Malformation: 2-Dimensional Operative Video

Thalamic cavernous malformations pose variable surgical challenges given that the location and size of the lesion often determine the approach surgical trajectory. The patient in this case has a large thalamic cavernous malformation that results in a mass effect on the third ventricle and directly abuts the lateral ventricle. A small interhemispheric craniotomy is performed to allow for an anterior interhemispheric transcallosal approach to the lesion. The lateral ventricle is accessed, and the septum is removed to enhance visualization of the surgical field. A small rim of normal parenchyma on the lateral margin of the thalamus is transgressed, and the cavernous malformation is entered. The lesion is removed in a piecemeal manner. Use of counter traction assists with the piecemeal removal. The lighted suction is critical during inspection and manipulation of the lesion within the resection cavity given the limited lighting deep within the cavity. The lesion was removed completely, and postoperative imaging confirms gross total resection. The patient gave informed consent for surgery and video recording. The institutional review board approval was deemed unnecessary. Used with permission from the Barrow Neurological Institute.

Supracerebellar Infratentorial Approach for Complex Thalamic Cavernous Malformation: 2-Dimensional Operative Video

Key points for the approach include the use of a supracerebellar infratentorial craniotomy, dynamic and gravity retraction, lighted bipolar forceps and suction, and stereotactic navigation. This patient has a large cavernous malformation extending from the midbrain to the thalamus in craniocaudal extent. The cavernous malformation extends to the midbrain surface along the interface with the ambient cistern, making it appropriate for the supracerebellar infratentorial approach. By cutting the tentorium access to the superior extension becomes feasible. The cavernous malformation is excised in a piecemeal manner utilizing a CO2 laser. Because removal of the large mass allowed the partial collapse of the cavity, a small segment of the cavernous malformation obscured by the collapse is retained cranially along the foramen of Monro. This situation required a return to the operating room for complete excision. The patient tolerated both procedures well and remained at her neurological baseline postoperatively. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. The surgical video has been used with permission from the Barrow Neurological Institute.

Parietooccipital Transventricular Approach for Thalamic Cavernous Malformation: 2-Dimensional Operative Video

The highly eloquent nature of the thalamus and the depth of the surgical field make thalamic cavernous malformations exceptionally challenging entities for surgical management, necessitating stereotactic navigation and lighted instruments for successful resection. This case demonstrates a patient with a large right dorsal thalamic cavernous malformation that is approached using the well-tolerated transparietooccipital lobule approach for ventricular access and subsequent resection of the lesion along the intraventricular surface. Stereotactic neuronavigation permits this transcortical approach with minimal transgression of normal parenchyma. The trajectory permits approach to the cavernous malformation along its greatest dimension to augment removal. A complete removal of the lesion is achieved. The patient remained at neurological baseline postoperatively. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Giant Cervical Cavernous Malformation: 2-Dimensional Operative Video

Cervical spinal cord cavernous malformations are rare but can be neurologically devastating lesions and, when symptomatic, are best treated with gross total resection to prevent progressive neurologic decline related to recurrent hemorrhage. This patient had a large high cervical cord cavernous malformation with evidence of recent hemorrhage. A midline myelotomy was utilized to enter the cavernous malformation. The cavernous malformation was then circumferentially separated from the spinal parenchyma and removed in a piecemeal manner. Postoperative imaging confirmed gross total resection of the lesion with preservation of the surrounding spinal cord. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Limited positive predictive value of diffusion tensor tractography in determining clinically relevant white matter damage in brain stem cavernous malformations: A retrospective study in a single center surgical cohort

PURPOSE

Diffusion tensor tractography (DTT) might reflect the postoperative clinical outcome of the patients with brain stem (BS) tumors correlating well with the neurological symptoms, but cavernous malformation (CM) is a hemorrhagic tumor prone to artifacts that may limit DTT. We set out to determine the correlation of DTT findings with the neurological examination before and after surgical resection in patients with BSCMs.

MATERIALS AND METHODS

DTT findings were evaluated bilaterally for fiber tract displacement or deviation, deformation and interruption in every patient before and after the surgery. Neurological examination was performed at admission, discharge and outpatient follow-up visit. The sensitivity, specificity, positive and negative predictive values of DTT were calculated both pre- and post-operatively.

RESULTS

There were 25 patients (9 men 16 women) with a mean age of 39.5±13.9 years. The mean size of the CMs was 6909±8374mm³ (range: 180-38,220mm³) The mean follow-up time was 42.7±23.2 months (range: 8 to 112 months). Preoperatively, the sensitivity, specificity, positive and negative predictive values of DTT for corticospinal tracts (CST) and medial lemnisci (ML) were 100%, 60%, 38.4%, 100% and 87.5%, 11.7%, 31.8%, 66.6%, respectively. Postoperatively, the sensitivity, specificity, positive and negative predictive values of DTT for CSTs and ML were 100%, 64.7%, 40%, 100% and 100%, 0%, 33.3%, 66.6%, respectively.

CONCLUSION

Positive findings on DTT such as fiber tract deviation, deformation, disruption or interruption should be taken cautiously before drawing conclusions of a clinically relevant damage of white matter tracts.

Thalamus Cavernous Malformation Resection of via Contralateral Anterior Interhemispheric Transcallosal Approach: Two-Dimensional Operative Video

Thalamic cavernous malformations (CM) are highly challenging surgically. In this illustrative video (Video 1), we present the case of a 36-year-old man with a CM at the left medial thalamus, which was successfully treated by a contralateral anterior interhemispheric transcallosal approach. Informed consent was obtained from the patient. Preoperative imaging demonstrated that the CM appeared to have reached the pial surface superiorly and medially, and diffusion tensor imaging showed the pyramidal tracts to be traveling laterally to the CM. Based on the "Two-point" principle and to avoid pyramidal tract impingement, an anterior interhemispheric transcallosal approach was chosen. Furthermore, to avoid excessive retraction on the ipsilateral hemisphere, we selected the contralateral trajectory over the ipsilateral trajectory. The head was positioned with the right side down; thus, the space between the right hemisphere and the falx could expand because of gravity autoretraction, which could minimize the need of retraction during the interhemispheric dissection. A small incision on the corpus callosum was performed under the guidance of neuronavigation, and the left ventricle was subsequently entered. After a thin layer of hemosiderin-stained pia was opened on the superior surface of the left thalamus, some sandlike old hemorrhagic component was removed for decompression, and the lesion was carefully dissected away from the normal parenchyma within the surrounding gliosis boundary. The CM was removed en bloc, and the deep venous anomaly was well protected. The patient did not experience any intraoperative changes shown by electrophysiologic monitoring, and he recovered well postoperatively.

A Rare Case of Supratentorial Cavernous Angioma Associated with Arterialized Developmental Venous Anomaly

The association of cavernous malformations and developmental venous anomalies (DVA) is well known, but the presence of arterial fistulous connection with the main venous collector has been reported in the literature only once. We report the unusual case of a hemorrhagic cavernous angioma associated with DVA characterized by a fine arterial supply to the main venous collector. During surgery, after the excision of the cavernous angioma, few small arterial feeders were found entering the main channel of the venous developmental anomaly. The presence of an arterial fistulous connection with the main venous collector of a DVA may be a possible mechanism involved in a higher bleeding potential of cavernous angioma.

Transsylvian, Carotid-Oculomotor Triangle Approach for Resection of a Rapidly Enlarging Midbrain-Pontine Cavernous Malformation: 3-Dimensional Operative Video

Cavernous malformations (CM) of the anterior midbrain are best reached through an orbitozygomatic (OZ) approach with removal of the orbital rim and wide Sylvian fissure dissection. Our surgical video demonstrates this approach to resect a ruptured CM in a 36-yr-old woman who presented with headaches, left face and left arm paresthesias/weakness, and right-sided partial oculomotor nerve (CN III) palsy. Initial magnetic resonance imaging (MRI) showed a midbrain CM, and the patient was managed conservatively. However, 1 wk later, she presented again with worsened left arm and leg weakness and complete CN III palsy. Seven Tesla MRI demonstrated a larger hematoma, and the CM with new mass effect and upper pons extension. The patient underwent a right modified OZ craniotomy and Sylvian fissure split under guidance of intraoperative neuronavigation and with neuromonitoring. The carotid-oculomotor triangle and the Liliequist membrane were dissected to access the midbrain, and CN III was identified and followed posteriorly to the midbrain. Confirmed with neuronavigation, a longitudinal incision of the midbrain was performed, and the CM was encountered. The hematoma and CM were debulked and removed in a piece-meal fashion, leaving hemosiderin-stained brain intact to prevent unnecessary additional damage to the midbrain. Postoperative MRI confirmed gross-total resection, and the patient's weakness recovered substantially. In this video, we demonstrate that the brainstem is no longer forbidden surgical territory, and show how the use of neuronavigation for surgical planning, positioning, and approach, in addition to the understanding of safe entry zones and meticulous microsurgical technique have made safe and effective surgery on the brainstem possible.

Large Cystic Cavernous Malformation in Infant with Novel KRIT1 Gene Abnormality

Intracranial cavernous malformation are vascular lesions that can present for urgent surgical intervention. Occurrence in the infant demographic is extremely rare, and presentation can vary greatly. We present a striking clinical image of a large cavernous malformation with a larger cystic component in an infant that was successfully treated with surgical intervention and found to harbor a de novo novel KRIT1 gene abnormality, which affected the nature of surveillance.

Stereotactic Radiosurgery for Brainstem Cavernous Malformations: An Updated Systematic Review and Meta-Analysis

OBJECTIVE

This study was conducted to achieve more conclusive evidence for the efficacy of stereotactic radiosurgery (SRS) for brainstem cavernous malformations (BSCMs).

METHODS

A literature search of PubMed, EMBASE, and Web of Science was performed and studies reporting the outcomes of SRS for BSCMs were included. The primary outcome was the pre-SRS and post-SRS hemorrhage rates; the pooled incidence rate ratio (IRR) with 95% confidence interval was chosen as effect size. Lesion control, symptom change, and radiation-related complications were evaluated.

RESULTS

A total of 576 patients across 14 studies were included in this meta-analysis. The post-SRS hemorrhage rate was significantly decreased compared with the pre-SRS rate (IRR, 0.123; P < 0.001), and the hemorrhage rate 2 years after SRS was significantly lower than that within 2 years after SRS (IRR, 0.317; P < 0.001). Ten among 14 studies have shown that the symptoms were improved or stationary after SRS. Lesion volume was reduced in 47.3% of the patients and was stationary in 49.4% on the last follow-up images. Symptomatic adverse radiation effects (AREs) developed in 7.3% and permanent AREs were observed in 2.2%. In subgroup analysis, studies having mean marginal dose of ≤13 Gy showed statistically significantly lower development of symptomatic AREs than those having mean marginal dose of >13Gy (2.0% vs. 10.8%; P = 0.008).

CONCLUSIONS

SRS using a relatively low marginal dose can be a safe and effective treatment for BSCM. Further prospective studies are necessary to confirm the optimal radiation dose and efficacy of SRS for BSCMs.

Suboccipital Craniotomy for Resection of a Dorsal Medullary Cerebral Cavernous Malformation: 2-Dimensional Operative Video

This video illustrates the case of a patient with familial cerebral cavernous malformation syndrome with a history of multiple symptomatic hemorrhages attributable to a medullary malformation. The patient had swallowing difficulties and gait instability that was progressively worsening. Informed consent was obtained for surgical exploration. The lesion was noted to abut the floor of the fourth ventricle and was approached using a suboccipital craniotomy. Several safe-entry zones on the floor of the fourth ventricle have been described. For lesions that abut the floor, or those that are exophytic, a direct point of entry into the lesion is selected. When possible, the opening into the floor of the fourth ventricle should be placed off midline. The technique of piecemeal resection of the lesion from the brainstem and preservation of normal, hemosiderin-stained brain is presented. Careful patient selection and respect for normal anatomy are of paramount importance in obtaining excellent outcomes in operations within or adjacent to the brainstem. This medullary lesion was resected completely.

Right Pretemporal-Transsylvian Approach for Resection of a Midbrain Cavernous Malformation: 3-Dimensional Operative Video

Brainstem cavernous malformations (CMs) account for 15% to 18% of all intracranial CMs1 and 13% of all cerebrovascular pathology in the posterior fossa.1,2 This video demonstrates the resection of a pontomesencephalic CM through a pretemporal approach through the oculomotor-tentorial triangle (OTT).3 A 49-yr-old woman presented with an acute onset of left hemiparesis, diplopia, vertigo, partial oculomotor, and facial palsy. Neuroimaging revealed a 25-mm diameter right pontomesencephalic CM with evidence of prior hemorrhage. Institutional Review Board approval and patient consent were obtained for surgery. A right orbitozygomatic craniotomy was performed, and the lesion was exposed through a pretemporal-transsylvian approach. After a wide Sylvian fissure split, the oculomotor nerve (CN III) was dissected away from the temporal lobe, and the temporal lobe was mobilized posteriorly to access the OTT. The posterior cerebral and superior cerebellar arteries were visualized in this triangle, and the cerebral peduncle and the CM were accessed deep to these arteries. After hematoma evacuation, the CM was resected in a piece-meal fashion using an intracapsular technique. Postoperative imaging confirmed the gross total resection of the lesion. The patient had persistent right CN III palsy and a slight worsening of left hemiparesis, which had resolved completely at the 6-mo follow-up. The OTT provides access to the upper ventrolateral pontomesencephalic area.3 This triangular surgical workspace is entered through a pretemporal-transsylvian corridor and widened with posterior temporal lobe retraction. The OTT is an important working space for accessing midbrain and upper pontine CMs posterolateral to CN III.

Infratentorial Developmental Venous Abnormalities and Inflammation Increase Odds of Sporadic Cavernous Malformation

GOAL

Sporadic brain cavernous malformations commonly correlate with developmental venous anomalies; however, developmental venous anomalies may exist without cavernous malformations. Infratentorial location and specific angioarchitectural features of the developmental venous anomaly increase the odds of a concomitant malformation. Animal data also suggest chronic inflammatory disease, oxidative stress, and angiogenesis promote cavernous malformation development. We sought to determine potential clinical and radiologic factors promoting development of sporadic cavernous malformations.

METHODS

One hundred and forty-five patients with sporadic, nonradiation-induced brain cavernous malformations (63 with radiologic-apparent and 82 with radiologic-occult developmental venous anomalies) were compared to developmental venous anomaly controls without associated malformation. Data collection included demographic information, comorbidities, medications at diagnosis, and location of the developmental venous anomaly and/or malformation. Logistic regression with likelihood ratios, odds ratios and 95% confidence intervals were calculated comparing malformation cases with controls. A similar analysis compared malformations with radiologic-apparent anomalies to controls.

RESULTS

Compared to controls, cases were more likely to have had a major infectious illness (10.3% versus 2.3%; P = .0003 and/or chronic inflammatory disease (31.7% versus 21.3%; P = .0184) prior to diagnostic magnetic resonance imaging. Infratentorial location was more common in cavernous malformation cases (31.7% versus 15.7% controls; P ≤ .0001) with similar findings in cavernous malformation with radiologic-apparent developmental venous anomalies versus controls.

CONCLUSIONS

Infratentorial developmental venous anomalies location, major infectious illness, and chronic inflammatory disorders increase the odds of sporadic cavernous malformation formation. Inflammation may promote local thrombosis of developmental venous anomalies, trigger angiogenic response through increased vascular permeability, or promote cavernous malformation through Toll-like receptor 4.

Hemorrhage, Seizures, and Dynamic Changes of Familial versus Nonfamilial Cavernous Malformation: Systematic Review and Meta-analysis

BACKGROUND

Cerebral cavernous malformations (CCMs) may be familial or nonfamilial. This systematic review compared the natural history of CCMs in familial compared with nonfamilial cases.

METHODS

We searched MEDLINE, Web of Science, and EMBASE for natural history studies on CCMs up to September 2018. We included studies that followed at least 20 untreated patients. Primary outcomes were hemorrhage, seizures, and neuroimaging changes in familial and nonfamilial cases. Incidence rate per person-year (PY) or lesion-year (LY) of follow-up were used to pool the data using fixed-effects or random-effects models. We used the incidence rate ratio for comparison.

RESULTS

We could not compare hemorrhage rates between familial and nonfamilial cases mainly owing to mixtures of subgroups of patients. The seizure rate was similar in familial and nonfamilial cases with pooled incidence rate of 1.5%/PY (95% confidence interval 1.1%-2.2%). The reseizure rate was higher than the seizure rate (P < 0.001). New lesion development was higher in familial cases (32.1%/PY vs. 0.7%/PY, P < 0.001). Signal change on neuroimaging ranged from 0.2%/LY to 2.4%/LY in familial cases. In familial cases, incidence rate of size change was 8%/PY (95% confidence interval 5.2%-12.2%) and 1.1%/LY (95% confidence interval 0.6%-1.6%).

CONCLUSIONS

Familial CCMs show higher dynamic changes than nonfamilial cases. However, the presence of actual dynamic changes needs further assessment in nonfamilial cases. CCMs demonstrate a low incidence of seizure. First-time seizure increases the chance of recurrent seizure. Seizure rate based on the location and type of the lesion should be investigated further.

Continuous ictal discharges with high frequency oscillations confined to the non-sclerotic hippocampus in an epileptic patient with radiation-induced cavernoma in the lateral temporal lobe

Background

Intraoperative electrocorticography (iECoG) recording is recommended for treating cavernoma related epilepsy. However, "interictal" paroxysmal activities are generally recordable but are not always identical to the epileptogenic zone.

Case description

We surgically treated a 15-year-old girl with drug-resistant epilepsy associated with radiation-induced cavernoma in the right lateral temporal lobe. iECoG revealed paroxysmal activities in the cortex around the cavernoma. Additionally, continuous subclinical "ictal" discharges with high-frequency oscillations (HFO), confined to the histologically non-sclerotic hippocampus, were recorded. Following additional hippocampectomy, a good seizure outcome was obtained.

Conclusion

iECoG and HFO analysis revealed high epileptogenicity in the non-sclerotic hippocampus of this patient.

Gamma Knife Radiosurgery for Trigeminal Neuralgia Caused by a Cavernous Malformation: Case Report and Literature Review

OBJECTIVE

Trigeminal neuralgia (TN) related to a brainstem cavernous malformation (CM) is a rare entity. We present the first radiosurgical management of a patient with TN secondary to a CM.

CLINICAL PRESENTATION

An 80-year-old female presented with a 33-year history of progressively severe TN refractory to medications. Imaging confirmed a solitary CM located at the pontine dorsal root entry zone of cranial nerve 5.

TREATMENT

Stereotactic radiosurgery of the trigeminal nerve was performed using the Leksell gamma knife. A single 4-mm isocenter of radiation was focused on the trigeminal nerve and a maximum dose of 80 Gy (40 Gy at the 50% isodose line) was delivered to the nerve.

RESULTS

At 1 year, the patient noted that the severe pain attacks had been reduced by 75%, although a background lingering discomfort persisted. Pain suppression medications had been significantly reduced to lamotrigine 100 mg twice daily. Her preoperative distribution of sensory dysfunction mildly increased.

CONCLUSION

For medically refractory TN related to a CM, radiosurgery of the afferent nerve may ameliorate pain without a major decrease in sensation. The more than 30-year history of pain in our patient may have reduced the chance of more significant pain relief.

Surgical treatment of an asymptomatic giant supratentorial cavernous hemangioma. Case report

A case is reported of a 19-year old patient with a supratentorial giant cavernous malformation (GCM). This was an incidental finding in the context of acute head trauma. Brain computed tomography (CT) scan and magnetic resonance imaging (MRI) revealed a giant supratentorial right mass. Surgical excision was performed, and histopathology findings were consistent with a cavernous malformation (CM). The patient had a complete neurological recovery. To our knowledge, this is the first case of a GCM in an asymptomatic patient with total surgical excision.

Recovery of consciousness after a brainstem cavernous malformation hemorrhage: A descriptive study of preserved reticular activating system with tractography

The aim of this study is to describe the imaging features, the relevant anatomy, and the fractional anisotropy (FA) values in diffusion tensor tractography (DTT) of the ascending reticular activating system (ARAS) fiber tracts in 2 patients who recovered from initial altered consciousness after presenting with a brainstem cavernous malformation (BSCM) hemorrhage. A DTT was performed in 2 patients with impaired consciousness after a brainstem cavernous malformation hemorrhage. A 1.5 T scanner was used to obtain the axial tensors. Post-processing was performed and the mean FA values were recorded. The FA maps were used to seed the following regions of interest: the ventromedial midbrain, the anterior thalamus bilaterally, and the hypothalamus bilaterally. The first case presented with posterior displacement of the dorsal raphè fiber tracts, with preservation of all the ascending reticular activating fiber tracts and spontaneous recovery of consciousness after 20 days. The second case presented with no destruction but also had posterior displacement of the inferior dorsal raphè fiber tracts, with recovery of consciousness 1 month after resection surgery. Described in this study are affected fibers of the ARAS, as well as the FA value abnormalities in 2 patients, with recovery of a transient disorder of consciousness after a BSCM hemorrhage.

Cavernous malformations are rare sequelae of stereotactic radiosurgery for brain metastases

The development of cavernous malformations many years following conventionally fractionated brain irradiation is well recognized and commonly reported. However, cavernous malformation induction following stereotactic radiosurgery (SRS) is largely unreported. Herein, we describe two cases of cavernous malformation formation years following SRS for brain metastases. A 20-year-old woman with breast cancer brain metastases received treatment with whole brain radiotherapy (WBRT), then salvage SRS 1.4 years later for progression of a previously treated metastasis. This lesion treated with SRS had hemorrhagic enlargement 3.0 years after SRS. Resection revealed a cavernous malformation. A 25-year-old woman had SRS for a brain metastasis from papillary thyroid carcinoma. Resection of a progressive, hemorrhagic lesion within the SRS field 2 years later revealed both recurrent carcinoma as well as cavernous malformation. As patients with brain metastases live longer following SRS, our cases highlight that the differential diagnosis of an enlarging enhancing lesion within a previous SRS field includes not only cerebral necrosis and tumor progression but also cavernous malformation induction.

Cavernous Malformation of a Thoracic Spinal Nerve Root: Case Report and Review of Literature

Intradural extramedullary spinal cavernous malformations (CMs) remain the least common variant of these lesions and can originate from the inner surface of the dura mater, the pial surface of the spinal cord, and the blood vessels in the spinal nerves. Root-based-only extramedullary CMs are very rare in the thoracic region with only four cases reported. We present a case of 56-year-old male with 1-year progression of lower extremities weakness. Magnetic resonance imaging demonstrated a hyperintense lesion in the upper thoracic region. Surgical exploration revealed a CM with origin in the second thoracic nerve root with gross total resection. Histopathological examination confirmed a CM. The patient had complete recovery of neurological function at 3 months interval. Intradural extramedullary CM is extremely rare entity that must be considered in the differential diagnosis of intradural extramedullary lesions. Surgical resection is the treatment of choice to prevent further neurological damage.

De novo cavernous malformation arising in the wall of vestibular schwannoma following stereotactic radiosurgery: case report and review of the literature

We report a novel case of a radiation-induced cavernous malformation developing in a vestibular schwannoma previously treated with stereotactic radiosurgery. Eleven years after treatment, the patient presented with a large predominantly cystic lesion in the cerebellopontine angle. We performed surgery, and a solid vascular lesion was identified within the schwannoma, which was determined to be a cavernous malformation after histopathological analysis. We review the literature of radiation-induced cavernous lesions, illustrating that while rare, these lesions do pose concern as a long-term complication of brain radiation therapy. We also discuss the possibility that radiation-induced cavernous malformation-like lesions are pathologically distinct from cavernous malformations.

Unedited microneurosurgery of a cavernous malformation of the pineal region

Background

Cavernous malformations are low-flow vascular malformations comprised of clusters of dilated sinusoidal channels lined with endothelial cells. The tortuous blood vessels also called vascular caverns lack muscular and elastic layers, and are filled by blood at different stages of thrombosis. Hemosiderin and gliosis often surround cavernomas. However, no neural tissue is present inside the lesion. Magnetic resonance images of cavernomas reveal a pathognomonic popcorn appearance produced by multiple small hemorrhages. Developmental venous anomalies are associated in around 30% of the cases. Cavernomas are very prevalent lesions ranging from 0.4 to 0.8% of the population. However, those located in the pineal region are very rare. Herein, we present the microsurgical treatment of a histologically confirmed cavernous malformation of the pineal region.

Case Description

A 33-year-old patient with a pineal region cavernoma and progressive hydrocephalus underwent right supracerebellar infratentorial paramedian approach in a sitting praying position. The surgical planning did not require neuronavigation, but anatomical landmarks for the proper approach. Under high magnification, the pineal region was accessed over the superior cerebellar surface. After a focused lateral opening of the dorsal membrane of the quadrigeminal cistern, small vessels running in the posterior wall of the third ventricle were carefully dissected. A yellowish hemosiderin staining tissue allowed us to recognize the vicinity of the lesion. A small cottonoid delimitated the posterior border of the malformation, nonetheless, the superior limits underwent microdissection to release some cerebrospinal fluid from the third ventricle. A precise marginal dissection with bipolar forceps, microdissectors, and a thumb-regulated suction tube encircled the lesion. Gently traction of the lesion with ring microforceps associated further detachment of the cavernoma with the suction tube. Cotton dissection and water dissection technique were useful as well. A piecemeal resection, which is indicated in lesions with a deep and eloquent location, allowed us a complete removal of the cavernoma. Accurate hemostasis and continuous saline irrigation maintained a clean surgical field along the procedure. The gliotic tissue was left behind to prevent damage of the surrounding structures. Under endoscopic vision, remnants in the lower margins of the operative field were carefully evaluated. Finally, the surgical area was flushed with saline irrigation to detect any bleeding, and a small piece of tachosil was placed over the cavity. The postoperative course was uneventful. The hydrocephalus resolved after surgery and it did not require any further procedure.

Conclusion

This unedited video offers all detailed aspects that a neurosurgeon as the senior author Juha Hernesniemi considers essential when performing an efficient and safe surgery for cavernous malformation of the pineal region.

Videolink

http://surgicalneurologyint.com/videogallery/iii-ventricle-cavernoma/.

Defining Long-Term Clinical Outcomes and Risks of Stereotactic Radiosurgery for Brainstem Cavernous Malformations

BACKGROUND

We evaluated clinical outcomes in patients with symptomatic brainstem cavernous malformations (CMs) treated by stereotactic radiosurgery (SRS).

METHODS

Between 1988 and 2016, Gamma Knife SRS was performed in 76 evaluable patients with solitary symptomatic brainstem CMs. Forty-nine (66%) were intrinsic (not reaching a pial or ependymal surface). Most patients (91%) had experienced 2 or more hemorrhages associated with new neurologic deficits. Fourteen patients (18%) underwent resection before radiosurgery. The median CM volume was 0.66 cm3 (range, 0.05-6.8), and the median margin dose was 15.0 Gy.

RESULTS

After SRS, 15 patients (20%) had an imaging confirmed new hemorrhage at a median follow-up of 48 months. The hemorrhage-free survival after SRS for brainstem CMs was 92% at 1 year, 87% at 3 years, and 85% at 5 years. The annual hemorrhage rate was 31% before and 4% after SRS. In univariate analysis, CM volume, previous surgical resection, and increased number of hemorrhages before SRS were significantly associated with a higher rate of hemorrhage after SRS. In multivariate analysis, only number of previous hemorrhages was significant (P < 0.0005; hazard ratio, 1.51, 95% confidence interval, 1.23-1.85). Symptomatic adverse radiation effects developed in 7 patients (9%). The rate of symptom deterioration related to hemorrhage or symptomatic adverse radiation effects was 10% at 1 year, 18% at 3 years, and 20% at 5 years.

CONCLUSIONS

Patients with an increased rate of hemorrhage before SRS had an increased risk of repeat hemorrhage and symptom deterioration rate after SRS. Intrinsic CM location did not significantly affect rates of symptom deterioration or rebleeding.

Awake Craniotomy for Removal of Left Insular Cavernous Malformation

The insula plays a crucial role in speech planning due to its connections with cortical and subcortical areas. Surgical management of cavernous malformation (CM) of the insula consists of total resection of the lesion and the surrounding gliosis to avoid or reduce seizures. When located in the dominant hemisphere, an awake craniotomy with intraoperative mapping reduces the risk of functional damage. The insula is covered by the operculum and has a relationship with the middle cerebral artery and its branches that run along its lateral surface. Therefore high expertise is required to manage the exposure of the insula and its complex anatomy. This video demonstrates the surgical management of a large left insular CM. A 29-year-old female with multiple CM and 7 years of partial seizures and recent onset of short memory loss. Neuroimaging showed a large left insular and planum polare CM with important mass effect and hemorrhage signs. The patient consented to surgery, and an awake pretemporal craniotomy was carried out with continuous motor evoked potential monitoring. No language function was localized in the superior temporal gyrus; therefore corticectomy of the middle portion was performed to expand the operative corridor. The vessel manipulation during wide opening of the sylvian fissure increased the risk of postoperative vasospasm and blood drain into the surgical field. The CM was exposed and completely removed without functional damage. The patient recovered from surgery without complications, and no seizures occurred at 2 months' follow-up. Postoperative imaging showed complete removal of the CM.