UNASSIGNED: Transvenous embolization (TVE) has been proven to be safe and feasible as an alternative management of brain arteriovenous malformations (AVMs). We presented four patients with a hemorrhagic brain AVM who underwent TVE and reviewed the relevant literature.
UNASSIGNED: Four patients underwent TVE of a hemorrhagic brain AVM in our center between July 2019 and July 2020. We retrospectively collected and analyzed the clinical and imaging data of these patients and those reported in previously published studies.
UNASSIGNED: Four patients with a hemorrhagic brain AVM were included. Nidus sizes ranged from 0.79 to 2.56 cm. Spetzler-Martin grade ranged from grade II to grade III. The AVM nidus was located in a deep brain region in three patients. One patient underwent TVE alone and three underwent combined transarterial and transvenous approaches. Digital subtraction angiography (DSA) demonstrated complete obliteration of the vascular malformation after embolization in all four patients. Three patients were independent [modified Rankin Scale (mRS) score ≤ 2] at discharge. All four patients were independent at the last follow-up. AVM obliteration was confirmed in all four patients at the last angiographic follow-up.
UNASSIGNED: Transvenous embolization can be used as an alternative treatment for contemporary management of brain AVMs, appropriate patient selection is essential to achieve a good clinical outcome.

OBJECTIVE: To evaluate frontal sinus complications developed after previous external craniotomies requiring frontal sinus reconstruction and their treatment with an endoscopic approach.
METHODS: We retrospectively evaluated 22 patients who referred to Sant\'Orsola-Malpighi University Hospital and Bellaria Hospital (Bologna, Italy) between 2005 and 2017. All patients presented with frontal sinus disease after frontal craniotomy with sinus reconstruction performed to treat various pathological conditions. We reported our experience in the endoscopic management of such complications and we reviewed the current literature concerning the endoscopic treatment of these conditions.
RESULTS: In total, 14 frontal mucoceles, 4 cases of chronic frontal sinusitis, 2 mucopyoceles and 2 fungus ball of the frontal sinus were identified. Endoscopic surgical treatment included 7 DRAF IIa, 1 DRAF IIb, 11 DRAF III and 3 DRAF IIc (modified DRAF III) approaches. The success rate of the surgical procedure was 86% (19/22 patients). Recurrence of the initial pathology occurred in three patients (14%) requiring a conversion of previous frontal sinusotomy into a DRAF III sinusotomy.
CONCLUSIONS: Frontal sinusopathy can be a long-term complication following craniotomies and may lead to potentially severe pathological conditions, such as mucoceles and frontal sinus inflammation. Its management is still debated and requires recovery of the patency of nasal-frontal route. Our study confirms that the endoscopic endonasal approach may offer a valid solution with low morbidity avoiding re-opening of the craniotomic access. For selected cases, endoscopic approach could also be performed simultaneously to craniotomy as a combined surgery to reduce the risk of short- and long-term complications. Long-term follow-up is mandatory in patients with a history of opened and reconstructed frontal sinus and should include imaging and endoscopic outpatient evaluation.

Spontaneous regression of an arteriovenous malformation (AVM) is the phenomenon of partial or complete obliteration of the vascular anomaly without any therapeutic intervention. Complete spontaneous regression is a rare event with limited previously reported cases in the literature. We present a new case of complete spontaneous regression of a right frontal AVM and report findings from the imaging studies. Furthermore, we present the findings of a detailed literature review and discuss hypotheses regarding the pathophysiology of this rare occurrence.

OBJECTIVE: Onyx, an ethylene-vinyl alcohol copolymer mixed in a dimethyl sulfoxide solvent, is currently one of the most widely used liquid materials for embolization of intracranial arteriovenous malformations (AVMs). The goal of this study was to define the risks and benefits of stereotactic radiosurgery (SRS) for patients who have previously undergone partial AVM embolization with Onyx.
METHODS: Among a consecutive series of 199 patients who underwent SRS between January 2007 and December 2012 at the University of Virginia, 25 patients had Onyx embolization prior to SRS (the embolization group). To analyze the obliteration rates and complications, 50 patients who underwent SRS without prior embolization (the no-embolization group) were matched by propensity score method. The matched variables included age, sex, nidus volume before SRS, margin dose, Spetzler-Martin grade, Virginia Radiosurgery AVM Scale score, and median imaging follow-up period.
RESULTS: After Onyx embolization, 18 AVMs were reduced in size. Total obliteration was achieved in 6 cases (24%) at a median of 27.5 months after SRS. In the no-embolization group, total obliteration was achieved in 20 patients (40%) at a median of 22.4 months after SRS. Kaplan-Meier analysis demonstrated obliteration rates of 17.7% and 34.1% in the embolization group at 2 and 4 years, respectively. In the no-embolization group, the corresponding obliteration rates were 27.0% and 55.9%. The between-groups difference in obliteration rates after SRS did not achieve statistical significance. The difference in complications, including adverse radiation effects, hemorrhage episodes, seizure control, and patient mortality also did not reach statistical significance.
CONCLUSIONS: Onyx embolization can effectively reduce the size of many AVMs. This case-control study did not show any statistically significant difference in the rates of embolization or complications after SRS in patients who had previously undergone Onyx embolization and those who had not.