BACKGROUND: Arachnoid cysts are cerebrospinal fluid-filled spaces that are typically congenital and treated conservatively or with fenestration when symptomatic. Chronic subdural hematomas (cSDHs) can arise in the presence of arachnoid cysts due to fragile leptomeningeal vessels or veins within the cyst wall or cyst lumen, leading to bleeding and subsequent hematoma formation. Middle meningeal artery (MMA) embolization is regularly used for the treatment of cSDH as an alternative to craniotomy and evacuation.
METHODS: Here, the authors present the first known report of the simultaneous resolution of an arachnoid cyst and cSDH following MMA embolization in an adult. A 24-year-old male presented to the emergency department with 1 month of worsening headaches. Imaging revealed the presence of a cSDH and ipsilateral arachnoid cyst. The cSDH was treated with MMA embolization using coils exclusively. Follow-up imaging 4 months after embolization demonstrated simultaneous resolution of both the hematoma and the arachnoid cyst.
CONCLUSIONS: MMA embolization has been used for the treatment of cSDH. In cases in which the hematoma is related to an arachnoid cyst, MMA embolization can also lead to the concurrent resolution of both pathologies. https://thejns.org/doi/10.3171/CASE24192.

UNASSIGNED: Direct carotid-cavernous fistulas (CCF) are primarily caused by head trauma. Some cases have also been attributed to iatrogenic injuries during endovascular procedures. However, the reports of functional endoscopic sinus surgery (FESS) associated with direct CCFs are extremely rare.
METHODS: A 52-year-old male worker, who suffered from chronic sinusitis and underwent functional endoscopic sinus surgery (FESS) performed by an otolaryngologist. Intra-operative finding indicated a left sphenoid sinus wall injury without internal carotid artery bleeding, which was repaired using mucosa and tissue glue. One month after discharge, he began experiencing tinnitus, headache and swelling in his left eye. Cerebral angiography revealed a direct carotid-cavernous fistula (CCF) on the left side. The patient underwent transarterial and transvenous stent-assisted coiling using detachable coils and Onyx, which alleviated his symptoms.
UNASSIGNED: A cavernous-carotid fistula following FESS is an exceedingly rare occurrence first reported by Karaman et al. in 2009. The incidence of internal carotid artery injury during FESS or endonasal endoscopic surgery (EES) is estimated to be between 0 and 0.1 %. Currently, there is no definitive explanation for the development of a carotid-cavernous fistula (CCF) post-FESS. Previous studies suggest that procedures like transsphenoidal surgery and EES can induce pseudoaneurysms in the internal carotid artery. If the cavernous pseudoaneurysm ruptures, it could lead to the formation of a CCF.
CONCLUSIONS: A direct cavernous-carotid fistula following functional endoscopic sinus surgery is a very rare. Consequently, when encountering patients with a carotid-cavernous fistula, relevant procedure history should be considered.

BACKGROUND: The fetal-type posterior cerebral artery (PCA) is defined as a variant anatomy in which the posterior communicating artery (PCOM) is larger than the hypoplastic or aplastic P1 segment of the PCA. The authors present the novel case of a patient with a duplicated right PCA in parallel with fetal-type and conventional PCAs supplying adjacent components of the PCA cerebral territory.
METHODS: A 59-year-old woman presented with a modified Fisher Scale score 4 subarachnoid hemorrhage. A right irregular PCOM aneurysm that measured 9.5 mm × 4.5 mm × 4.5 mm arose from the base of a variant branch supplying a portion of the PCA, rather than a conventional PCOM, and was found on digital subtraction angiography. Following endovascular coil embolization, the patient was discharged home.
CONCLUSIONS: The fetal-type variant has implications for thromboembolic events. If an embolism occludes the anterior circulation in a patient with a fetal-type PCA, it may result in an infarct in the PCA territory. Awareness of cerebral arterial anatomy, including an atypical collateral supply, informs a treating team\'s latitude in tolerance of which sites must be preserved and which can be safely sacrificed. https://thejns.org/doi/10.3171/CASE23735.

UNASSIGNED: Cerebral aneurysms located along the internal carotid artery at the origin of the ophthalmic artery can be treated through open surgery or endovascular technique. The former affords more certainty of aneurysm obliteration, while the latter poses less risk to vision. Flow diversion is an increasingly accepted treatment for side-wall carotid aneurysms, although location at the branch point of the ophthalmic artery is known to moderate occlusion outcomes.
UNASSIGNED: We present a case of a middle-aged female patient with a morphologically irregular 4-mm ophthalmic artery aneurysm (OphA) and a smaller superior hypophyseal artery (SHA) aneurysm whose successful and uncomplicated obliteration by flow diversion with adjunctive coiling was predicted via a balloon test occlusion (BTO). BTO was employed prior to stent placement to confirm a) ophthalmic artery distal collateralization with external carotid artery (ECA) branches and b) preserved arterial flow in the retina visualized via fundoscopy. At 1 year following angiography, the patient had no postoperative deficits and benefitted from complete occlusion of the OphA and SHA.
UNASSIGNED: OphAs constitute a complex surgical disease that is historically associated with high visual morbidity. We present a novel advanced endovascular technique of BTO followed by flow diversion with adjunctive coiling that successfully obliterated an OphA while preserving vision.

Intracranial \"kissing\" aneurysms are rare vascular conditions described as two anatomically adjacent aneurysms originating from either the same or different arteries, with their walls pressed together. Two-dimensional angiography was formerly considered the gold standard for diagnosis, with the three-dimensional rotational type now offering more insightful details about vascular discrepancies. The treatment of anterior communicating artery (AcoA) \"kissing\" aneurysms poses significant challenges, with surgical clipping proving difficult due to their deep midline location or the bilateral anterograde arterial supply. However, advancements in endovascular coil embolization, such as dual-volume reconstruction, can assist in diagnosis. This study presents the case of a 50-year-old patient who was diagnosed with \"kissing\" aneurysms of the AcoA. The patient underwent surgical clipping and showed no pathological follow-up findings. The surgical intervention often provides a more direct and effective approach. This case contributes to the body of knowledge surrounding the management of this complex disease.

UNASSIGNED: The twig-like middle cerebral artery (MCA) is rare and has a plexiform network of small vessels that replaces the MCA trunk, with a prevalence ranging from 0.11 %-1.17 %. It can be associated with an aneurysm. A Marathon microcatheter may be an alternative for coiling procedures. However, this technique has rarely been reported.
METHODS: A 63-year-old man suffered from headaches. The neurological examination results were unremarkable. Angiography revealed a twig-like MCA with an unruptured aneurysm. Due to stenosis of the aneurysm neck, a Marathon microcatheter was used to successfully reach the aneurysm, and coiling was completed with Chinese Visee coils. Postoperatively, the patient recovered uneventfully. Due to the lack of ischemic changes in the right hemisphere, the patient was kept under follow-up observation. At the 8-month follow-up by telephone, the patient was healthy.
UNASSIGNED: Aneurysms in the twig-like MCA may have stenosis of the aneurysm neck, and routine microcatheters used to deliver coils are often too thick to catheterize the aneurysm neck. The Marathon microcatheter has a distal inner diameter (ID) of 0.013, and as an alternative for coiling procedures, it may be soft enough to thin enough to go into the aneurysm. However, it can be used in the delivery of certain coils.
CONCLUSIONS: Aneurysms in the twig-like MCA are difficult to catheterize with the routine microcatheters used to deliver coils. A Marathon microcatheter may be used to perform the coiling procedure. However, only certain coils that match the Marathon microcatheter can be chosen.

BACKGROUND: Pediatric intracranial aneurysms (IAs) are rare and have distinct clinical profiles compared to adult IAs. They differ in location, size, morphology, presentation, and treatment strategies. We present our experience with pediatric IAs over an 18-year period using surgical and endovascular treatments and review the literature to identify commonalities in epidemiology, treatment, and outcomes.
METHODS: We identified all patients < 20 years old who underwent treatment for IAs at our institution between 2005 and 2020. Medical records and imaging were examined for demographic, clinical, and operative data. A systematic review was performed to identify studies reporting primary outcomes of surgical and endovascular treatment of pediatric IAs. Demographic information, aneurysm characteristics, treatment strategies, and outcomes were collected.
RESULTS: Thirty-three patients underwent treatment for 37 aneurysms over 18 years. The mean age was 11.4 years, ranging from one month to 19 years. There were 21 males (63.6%) and 12 females (36.4%), yielding a male: female ratio of 1.75:1. Twenty-six (70.3%) aneurysms arose from the anterior circulation and 11 (29.7%) arose from the posterior circulation. Aneurysmal rupture occurred in 19 (57.5%) patients, of which 8 (24.2%) were categorized as Hunt-Hess grades IV or V. Aneurysm recurrence or rerupture occurred in five (15.2%) patients, and 5 patients (15.2%) died due to sequelae of their aneurysms. Twenty-one patients (63.6%) had a good outcome (modified Rankin Scale score 0-2) on last follow up. The systematic literature review yielded 48 studies which included 1,482 total aneurysms (611 with endovascular treatment; 656 treated surgically; 215 treated conservatively). Mean aneurysm recurrence rates in the literature were 12.7% and 3.9% for endovascular and surgical treatment, respectively.
CONCLUSIONS: Our study provides data on the natural history and longitudinal outcomes for children treated for IAs at a single institution, in addition to our treatment strategies for various aneurysmal morphologies. Despite the high proportion of patients presenting with rupture, good functional outcomes can be achieved for most patients.

There is one reported case of a pancreatoduodenal fistula that was managed using combined coil embolization and fibrin glue after the failure of other methods. Herein, we document this case to highlight the value of coil embolization and fibrin glue as surgical alternatives for fistula treatment. We present a case of a 39-year-old female patient who has a known case of Crohn\'s disease (CD) and presented with an enterocutaneous fistula (ECF) after her most recent surgery. With the failure of conservative approaches and as she refused any surgical interventions, fibrin glue injection and coiling were used. As a conclusion, embolization may work well as a surgical management alternative due to its simplicity.

Developmental anomalies of internal carotid artery (ICA), being rare entities, are mostly asymptomatic by themselves because of good collateral supply. However, when present with other associated intracranial anomalies requiring treatment, there can be catastrophic consequences, if special attention is not paid to this condition. We present a case of 36 years old male, who reported to our emergency department with complaints of headache and loss of consciousness. He was diagnosed as a case of ruptured anterior communicating aneurysm with subarachnoid hemorrhage and agenesis of left ICA with trans-cavernous anastomosis. He underwent clipping of aneurysm and was discharged uneventfully. This report highlights the importance of skillful microsurgical clipping in extremely high-risk conditions, in contemporary era of hybrid neurosurgeons.

Bilateral distal anterior cerebral artery (DACA) aneurysms also called \"kissing aneurysms\" or \"mirror aneurysm\" are extremely rare, accounting for only 0.2% of all intracranial aneurysms. There have only been a few examples of mirror DACA aneurysms reported in the literature. Here, we report a rare case of mirror DACA aneurysm in a middle aged female with its successful clipping. Patient was admitted with severe headache and altered sensorium. Computed tomography (CT) head was suggestive of anterior inter-hemispheric hematoma. Digital subtraction angiography (DSA) was done which was suggestive of two distal anterior cerebral artery aneurysms located at same anatomical position. It was treated through microsurgical clipping. Mirror image DACA aneurysms are rare occurrence. All patients with ruptured DACA aneurysms should have angiography with 3D reconstruction studies. This aids in determining the aneurysm\'s morphology and planning treatment accordingly.