Long-Term Outcome of Time-Staged Gamma Knife Radiosurgery for Large Arteriovenous Malformations.

BACKGROUND: Treatment for large (> 10 mL) arteriovenous malformations (AVMs) remains highly challenging. This study evaluated long-term effect of time-staged gamma knife radiosurgery (GKS) for large AVMs. METHODS: For patients with large AVMs treated by time-staged GKS over 10 years, time-staged GKS was repeated every three years targeting the entire nidus if total obliteration was not achieved. Obliteration rate and post-GKS complications were assessed based on 10 mL volume interval of AVMs. Prognostic factors for these outcomes were evaluated using Cox regression analysis. RESULTS: Ninety-six patients were analyzed. For AVMs in the 10-20 mL subgroup, a dose ≥ 13.5Gy yielded higher obliteration rate in the first GKS. In the 20-30 mL subgroup, a second GKS significantly boosted obliteration. AVMs > 30 mL did not achieve any obliteration with the first GKS. Among 35 (36.4%) cases lost to follow-up, 7 (7.2%) were lost due to GKS complications. Kaplan-Meier analysis showed that each subgroup needed different time for achieving 50% favorable obliteration outcome rate: 3.5, 6.5, and 8.2 years for 10-20 mL, 20-30 mL, and > 30 mL subgroup, respectively. Total obliteration rate calculated by intention-to-treat method: 73%, 51.7%, 35.7%, respectively, 61.5% overall. Post-GKS hemorrhage and chronic encapsulated expanding hematoma (CEEH) occurred in 13.5% and 8.3% of cases, respectively. Two patients died. Dose and volume were significant prognostic factors for obliteration. Initial AVM volume was a significant prognostic factor of post-GKS hemorrhage and CEEH. CONCLUSION: Time-staged GKS for large AVMs less than 30 mL has highly favorable long-term outcome and a tolerable complication rate.

Chronic expanding pituitary hematoma with calcification resulting from pituitary adenoma: illustrative case.

BACKGROUND: Pituitary apoplexy (PA) is characterized by sudden headache, vomiting, visual dysfunction, anterior lobe dysfunction, and endocrine disorder due to bleeding or infarction from a pituitary adenoma. PA occurs in approximately 0.6-10% of pituitary adenomas, more commonly in men aged 50-60 years, and more frequently in nonfunctioning and prolactin-producing pituitary adenomas. Further, asymptomatic hemorrhagic infarction is found in approximately 25% of PA. OBSERVATIONS: A pituitary tumor with asymptomatic hemorrhage was detected on head magnetic resonance imaging (MRI). Thereafter, the patient underwent head MRI every 6 months. After 2 years, the tumor was enlarged and visual dysfunction was noticed. The patient underwent endoscopic transnasal pituitary tumor resection and was diagnosed with a chronic expanding pituitary hematoma with calcification. The histopathological findings were very similar to those of chronic encapsulated expanding hematoma (CEEH). LESSONS: CEEH associated with pituitary adenomas gradually increases in size, causing visual dysfunction and pituitary dysfunction. In case of calcification, total removal is difficult due to adhesions. In this case, calcification developed within 2 years. A pituitary CEEH, even when showing calcification, should be operated on, as visual function can be fully recovered.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature / Un hematoma encapsulado crónico expansivo que se desarrolló 15 años después de la intervención quirúrgica con bisturí de rayos gamma para tratar una malformación arteriovenosa cerebral: informe de caso y revisión bibliográfica

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS (AU)

Informamos de un caso de hematoma encapsulado crónico expansivo inducido por una intervención quirúrgica con bisturí de rayos gamma (GKS) con una amplia revisión bibliográfica. Un joven de 17 años se sometió a una GKS después de una embolización por malformación arteriovenosa (MAV) en el lóbulo frontal derecho, y la MAV desapareció por completo. Desarrolló una convulsión generalizada 15 años después de la GKS. La resonancia magnética (RM) mostró un pequeño cambio edematoso en la ubicación de la MAV. Su ataque epiléptico se controló con un anticonvulsivo. Su epilepsia se repitió 3 años después, y la RM reveló un hematoma intracerebral con un edema circundante extenso en la misma lesión. Se sometió a una angiografía cerebral y se evitó la recidiva de la MAV. El hematoma se extirpó quirúrgicamente, y el hallazgo intraoperatorio confirmó un antiguo hematoma con una hiperplasia capsular y capilar, sin desarrollo de angioma cavernoso. El diagnóstico final fue un hematoma encapsulado crónico expansivo secundario después de la GKS. Este es el primer informe que muestra los hallazgos del diagnóstico por imagen en la fase temprana de este efecto tardío después de la GKS (AU)

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature.

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

Chronic Encapsulated Expanding Hematoma After Gamma Knife Thalamotomy for Essential Tremor.

There have been no previous reports of chronic encapsulated expanding hematoma after Gamma Knife thalamotomy. The present case underwent Gamma Knife thalamotomy for essential tremor at the age of 78 years. Three- and 12-month posttreatment magnetic resonance imaging (MRI) showed small T2 high-intensity lesions on the target and along with the internal capsule. Hemiparesis developed 17 months after the treatment. Twenty months post treatment, T2-MRI showed a hypointense mass across the target and internal capsule. Gradual expansion of the mass was confirmed on MRI at 26-38 months. A 54-month posttreatment MRI showed marked expansion of the mass with multiple cysts surrounded by a T2-hypointense rim. Gadolinium-enhanced T1-MRI showed partial enhancement of the mass. MRI findings suggested a radiation-induced cavernoma. Hemiparesis, dysesthesia, and pain on the right side of the body persisted even after steroid therapy for several months. Long-term careful observation is necessary after Gamma Knife thalamotomy.

Chronic encapsulated expanding hematomas after stereotactic radiosurgery for intracranial arteriovenous malformations.

OBJECTIVE: Cerebral arteriovenous malformations (AVMs) are rare cerebral vascular lesions that are associated with high morbidity and mortality from hemorrhage; however, stereotactic radiosurgery (SRS) is a well-validated treatment modality. Few reports have delineated a subgroup of patients who develop delayed chronic encapsulated expanding hematomas (CEEHs) despite angiographic evidence of AVM obliteration following radiosurgery. In this report, the authors performed a retrospective review of more than 1000 radiosurgically treated intracranial AVM cases to delineate the incidence and management of this rare entity. METHODS: Between 1988 and 2019, 1010 patients with intracranial AVM underwent Gamma Knife SRS at the University of Pittsburgh Medical Center. In addition to a review of a prospective institutional database, the authors performed a retrospective chart review of the departmental AVM database to specifically identify patients with CEEH. Pertinent clinical and radiological characteristics as well as patient outcomes were recorded and analyzed. RESULTS: Nine hundred fifty patients with intracranial AVM (94%) had sufficient clinical follow-up for analysis. Of these, 6 patients with CEEH underwent delayed resection (incidence rate of 0.0045 event per person-year). These patients included 4 males and 2 females with a mean age of 45.3 ± 13.8 years at the time of initial SRS. Four patients had smaller AVM volumes (4.9-10 cm3), and 3 of them were treated with a single SRS procedure. Two patients had larger-volume AVMs (55 and 56 cm3), and both underwent multimodal management that included staged SRS and embolization. Time to initial recognition of the CEEH after initial SRS ranged between 66 and 243 months. The time between CEEH recognition and resection ranged from 2 to 9 months. Resection was required because of progressive neurological symptoms that correlated with imaging evidence of gradual hematoma expansion. All 6 patients had angiographically confirmed obliteration of their AVM. Pathology revealed a mixed chronicity hematoma with areas of fibrosed blood vessels and rare areas of neovascularization with immature blood vessels but no evidence of a persistent AVM. All 6 patients reported persistent clinical improvement after hematoma resection. CONCLUSIONS: CEEH after SRS for AVM is a rare complication with an incidence rate of 0.0045 event per person-year over the authors' 30-year experience. When clinical symptoms progress and imaging reveals progressive enlargement over time, complete resection of a CEEH results in significant clinical recovery. Knowledge of this rare entity facilitates timely detection and eventual surgical intervention to achieve optimal outcomes.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature.

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

Chronic encapsulated expanding hematoma after stereotactic radiosurgery of cerebral arteriovenous malformation.

Stereotactic radiosurgery has become excellent alternative treatment for cerebral arteriovenous malformations (AVM). This technique has expanded to treatment of larger AVM which is not amenable to surgical management. However, its variable adverse effects should be also taken into considerations sincerely because of radiobiological characteristics such as delayed onset and progressive neurological deteriorations. Herein, we report a case in which progressively expanding hemorrhagic cyst with repeated bleedings so called chronic encapsulated expanding hematoma was developed on several years after radiosurgery treatment. Neurological and radiological findings were improved by surgical removal.

Chronic encapsulated expanding hematoma after stereotactic radiosurgery of cerebral arteriovenous malformation

Stereotactic radiosurgery has become excellent alternative treatment for cerebral arteriovenous malformations (AVM). This technique has expanded to treatment of larger AVM which is not amenable to surgical management. However, its variable adverse effects should be also taken into considerations sincerely because of radiobiological characteristics such as delayed onset and progressive neurological deteriorations. Herein, we report a case in which progressively expanding hemorrhagic cyst with repeated bleedings so called chronic encapsulated expanding hematoma was developed on several years after radiosurgery treatment. Neurological and radiological findings were improved by surgical removal.