Azygos anterior cerebral artery shield masquerading as an aneurysm.

Background: Anterior cerebral artery (ACA) aneurysms are among the rare intracranial aneurysms and accounts for small fraction of all the intra cranial aneurysms. These carry a high risk of rupture. Their deep intra hemispheric location and close relationship with the pericallosal–callosomarginal bifurcation often make their identification and characterization challenging on routine imaging. While DSA (digital subtraction Angiography) remains the gold standard for diagnosis the intra cranial aneurysms, CT angiography (CTA) is a non-invasive and rapid modality for their detection and characterization. Objective: Here we report five cases of ACA aneurysms to describe the CT angiography findings in five cases of ACA aneurysms. Materials and Methods: This observational prospective study includes five patients diagnosed with ACA aneurysms on CT angiography within a span of 3 months. These patient presented with acute severe headache and underwent CT Angiography at Department of Radio diagnosis, BKL Walawalkar Rural Medical College, hospital, Chiplun, Ratnagiri, Maharashtra, India. Three patients presented with incidentally detected unruptured aneurysms, while two presented with subarachnoid hemorrhage secondary to aneurysmal rupture. All patients underwent CT angiography on a 32-slice scanner, with multiplanar and three-dimensional volume-rendered reconstructions for detailed morphologic assessment. Results: Three unruptured aneurysms were indentified, saccular in configuration, arising from the ACA and the ACoM, while the other two cases demonstrated a ruptured aneurysm with subarachnoid hemorrhage along the interhemispheric fissure. Conclusion: ACA aneurysms, although rare, can be confidently diagnosed on CT angiography. Recognizing their characteristic imaging features and anatomical relationships is essential for early detection, differentiation of ruptured from incidental lesions, and guiding therapeutic planning.

Cerebral aneurysms are occasionally associated with anomalies of the cerebral arteries. Most reports on anomalies of the anterior cerebral artery have been concerned with hypoplasia, fenestration and the infra-optic course of the A1, variant A1 perforators or Heubner's artery, multi-channeled anterior communicating artery, and azygos anterior cerebral artery. Distal anterior cerebral artery (ACA) aneurysms are known to have a poor clinical course and prognosis compared to other supratentorial aneurysms. The presence of the unpaired, distal, postcommunicating (A2) segment of the ACA is very rare in adults. We describe a patient with a ruptured aneurysm arising from the proximal end of the azygos ACA, first surgically treated with clipping and then with endovascular coiling. A 37-year-old woman at 34 weeks' gestation was transferred to our emergency room with sudden onset of severe headache and vomiting. Computed tomography (CT) revealed subarachnoid hemorrhage in the basal cisterna and the sylvian and interhemispheric fissures. Cerebral angiography showed an azygos ACA, a saccular aneurysm at the junction of the azygos ACA and the right A1 segment. A right fronto-temporal craniotomy was performed in the day of admission, and the neck of the aneurysm was clipped. One year later, an angiographic control examination revealed a regrowth of the aneurysm. The patient underwent endovascular treatment with coiling. Aneurysms of the azygos ACA are rare and their pathogenesis and course are still a matter of discussion. Developmental abnormalities or dynamic vessel wall stresses can explain the high incidence of aneurysms in these cases. The association of a rare anatomical variant with an aneurysm in the same location may suggest an embryogenesis alteration in the Willis circulation.

Some cases of aneurysms originating from the fenestrated A1 segment of the anterior cerebral artery (ACA) have been reported, but the pitfalls of the surgical procedure have not been well determined. We herein report 2 cases of a saccular aneurysm arising from the fenestrated A1 segment. Case 1 was a 72-year-old man incidentally diagnosed with an unruptured left ACA aneurysm on magnetic resonance imaging (MRI). Cerebral angiography revealed a saccular aneurysm arising from the proximal end of the left A1 segment. He underwent surgical clipping via the left pterional approach. The aneurysm originated from the proximal bifurcation of the fenestrated left A1 segment. A fenestrated ring clip was applied to obliterate the aneurysmal neck and one small fenestrated trunk, preserving the other fenestrated trunk and perforators around the fenestration. Case 2 was a 73-year-old man incidentally diagnosed with an unruptured ACA aneurysm on MRI. Cerebral angiography revealed a saccular aneurysm arising from the proximal end of the fenestrated left A1 segment. He underwent surgical clipping via the interhemispheric approach. The aneurysm originated from the proximal bifurcation of the fenestrated left A1 segment. A fenestrated ring clip was applied to obliterate the aneurysmal neck and one hypoplastic fenestrated trunk, preserving the other fenestrated trunk and perforators around the aneurysm. Detailed intraoperative evaluations of the anatomical structure and hemodynamics around the fenestration are important. The intentional obliteration of a fenestrated trunk and application of fenestrated clips need to be considered in difficult cases in order to expose the aneurysmal neck.

Background: Distal anterior cerebral artery (ACA) aneurysms occur more frequently in the genu portion and much less frequently in the supracallosal portion (A4–A5). This report describes two cases of ruptured cerebral aneurysms occurring at the supracallosal portion successfully treated with coil embolization. Case Description: Case 1 involved a 61-year-old female with sudden-onset headache and vomiting attributed to subarachnoid hemorrhage (SAH). Digital subtraction angiography (DSA) revealed a bihemispheric ACA and aneurysm in the supracallosal portion. Coil embolization was performed, and the patient was discharged without neurological deficit. Case 2 involved a 35-year-old man with severe headache and disturbance of consciousness caused by SAH. DSA showed an aneurysm in A4 of the accessory ACA, and coil embolization was performed. After rehabilitation, he was discharged with a modified Rankin scale score of 2. Conclusion: Coil embolization for a ruptured aneurysm at the supracallosal portion can yield good results if the patient is appropriately selected.

To evaluate the follow-up results of patients who underwent surgical treatment for distal anterior cerebral artery (pericallosal artery) aneurysms and compare our results with the literature. Nineteen patients were operated between 2000 and 2013 with preoperative angiography and computed tomography (CT) studies. Fisher"s classification and World Federation of Neurosurgical Societies (WFNS) subarachnoid hemorrhage (SAH) scale were used to classify the CT findings of the patients. In addition to the clinical and radiological analyses, bibliographical review in indexed databases was also performed. The female/male ratio was 4:1 and the average age was 34 years. The right side was affected in 53% of cases and 42% of the aneurysm was ruptured. Distribution of the ruptured aneurysms based on Fisher"s classification was as follows: Fisher IV in 25% of the cases, Fisher III in 37.5%, Fisher II in 12.5%, and Fisher I in 25% of the cases. The ruptured aneurysms were Grade I in 50% of cases, Grade III in 12.5%, and Grade IV in 37.5% of the cases according to the WFNS grading scale. The average size of the aneurysms was 3.5 mm, and ranged from 3 to 8 mm. One was fusiform and the others were saccular type of aneurysms. The aneurysm was located in fronto-polar artery in 53% of the cases, while in the callosomarginal artery in 47% of the cases. Multiple aneurysms were detected in 6 patients. There was no mortality due to surgery. Pericallosal artery aneurysms should have a better prognosis than the aneurysms located in the other parts of the circle of Willis. Complications are related to the patients" age. If possible, these aneurysms should always be clipped due to potential risk of bleeding and difficulty of embolization.

The Modified Trapping Technique for Pericallosal Artery Fusiform Aneurysm

Despite continuous advances in microsurgical and endovascular techniques, the treatment of complex aneurysms remains challenging. Aneurysms that are dilemmatic for conventional clipping or endovascular coiling often require bypass as part of a strategy to reduce the risk of ischemic complications. In anatomically favorable sites, the intracranial-intracranial in situ bypass may be an appealing choice. This article details the surgical strategies, operative nuances, and clinical outcomes of this technique with a consecutive series in our department. A retrospective review of a prospectively maintained neurosurgical patient database was performed to identify all patients treated with side-to-side in situ bypass from January 2016 to June 2022. In total, 12 consecutive patients, including 12 aneurysms, were identified and included in the series. The medical records, surgical videos, neuroimaging studies, and follow-up clinic notes were reviewed for every patient. Of the 12 aneurysms, there were 5 middle cerebral artery aneurysms, 4 anterior cerebral artery aneurysms, and 3 posterior inferior cerebellar artery aneurysms. The morphology of the aneurysms was fusiform in 8 patients and saccular in the remaining 4 patients. There were 3 patients presented with subarachnoid hemorrhage. The treatment modality was simple in situ bypass in 8 cases and in situ bypass combined with other modalities in 4 cases. Bypass patency was confirmed in all cases by intraoperative micro-doppler probe and (or) infrared indocyanine green (ICG) video angiography intraoperatively and with digital subtraction angiography (DSA) or computed tomography angiography (CTA) postoperatively. None of the patients developed a clinically manifested stroke due to the procedure though a callosomarginal artery was intentionally removed in one patient. The median follow-up period was 16.2 months (6-36). All patients had achieved improved or unchanged modified Rankin scale scores at the final follow-ups. Cerebral revascularization technique remains an essential skill for the treatment of complex aneurysms. The in situ bypass is one of the most effective techniques to revascularize efferent territory when vital artery sacrifice or occlusion is unavoidable. The configuration of in situ bypass should be carefully tailored to each case, with consideration of variations in anatomy and pathology of the complex aneurysms.

We report a rare case with a ruptured aneurysm of the bihemispheric anterior cerebral artery(ACA), a rare anomaly of the ACA. A 50-year-old female experienced a sudden onset of severe posterior cervical pain. CT revealed diffuse subarachnoid hemorrhage(SAH)and intra cerebral hemorrhage of the left rectal gyrus. Cerebral angiography showed the left bihemispheric ACA and hypoplasia of the right ACA. A saccular aneurysm was indicated at the A1-A2 junction of the left bihemispheric ACA. A neck clipping was performed completely through the right transsylvian approach. There are several reports of an aneurysm with bihemispheric ACA, but all cases are distal ACA aneurysms. In this case, the aneurysm was proximal to the bihemispheric ACA and such aneurysms have not been reported.

Treatment of a Fusiform Anterior Cerebral Artery Aneurysm by Remodeling the Circle of Willis with Flow Diversion: A Novel Technical Note

The microanatomy features of cerebral arteries may be variable and may be different in different ethnic groups. To study the anterior cerebral artery (ACA) anatomy in North-West Indian cadavers. Microanatomy features of the ACA were studied in 15 formalin fixed human cadaveric brains under microscope. The outer diameter, length, and number of perforating branches with respective anomalies were measured for each of the following vessels: ACA (proximal A1 segment to distal A2 segment), anterior communicating artery (ACoA), Recurrent artery of Heubner (RAH), and callosomarginal artery and photographed for documentation. The mean length and external diameter of right and left A1 segment was 12.09 mm and 12.0 mm and 2.32 mm and 2.36 mm respectively. Narrowing, duplication, and median ACA were seen in 6.6%, 3.3% and 6.6% of the vessels respectively. Complex ACoA type was seen in 40% cadavers. RAH originated at an average point of 0.2 mm distal to ACoA, but in one cadaver it arose 5 mm proximal to ACoA. Double RAH was found in 26.6%. The course of RAH in relation to A1 was superiorly in 60%, in anteriorly 30% and posteriorly in 10% of cadavers. The orbitofrontal artery (OFA) and frontopolar artery (FPA) arose from A2 in 83.3% to 40% respectively. The mean distance of OFA and FPA from ACoA was 4.17 mm and 8.5 mm respectively. After giving rise to central, callosal and cortical branches, pericallosal artery terminated near the splenium of the corpus callosum or on the precuneus as the inferomedial parietal artery. Knowledge of the microvascular anatomy is indispensable and it is mandatory to be aware of the possible variations in the anomalies to minimize morbidity.

The clinical case of simultaneous endovascular bloodstream exclusion of arteriovenous malformation and saccular aneurysm in parturient woman is presented. Onyx liquid adhesive composition and monospiral aneurysm occlusion technique were used. Patient X., 31, was hospitalized to the clinic on the 10th day of the postpartum period. From the anamnesis: twice (at 20th and 27th weeks of pregnancy) patient suffered intraventricular hemorrhage due to the rupture of arteriovenous malformation in the posterior third of the corpus callosum, left lateral ventricle and left parietal lobe of the brain. After the first hemorrhage a conservative treatment tactic was determined, given the high risk of complications associated with the surgical intervention for the mother and fetus. After the second hemorrhage endovascular embolization of malformation was suggested, however, the patient and her husband refused surgery, preferring conservative therapy with subsequent surgical treatment after delivery. In addition to the malformation, according to the data of selective cerebral subtraction angiography multiple cerebral saccular aneurysms of the left Anterior Cerebral – Anterior Communicating Artery and 2 Anterior Cerebral Artery aneurysms (A2-A2, A3-A4-segments) on the right side were diagnosed. Endovascular subtotal embolization of arteriovenous malformation and occlusion of the right Anterior Cerebral Artery (A2-A3-segment) saccular aneurysm were performed during the operation. A control angiographic examination after 3 months showed a complete exclusion of these arteriovenous malformation and saccular aneurysm and disappearance of all aneurysms of the left Anterior Cerebral Artery – Anterior Communicating Artery and right Anterior Cerebral Artery (A3-A4-segment).

IntroductionKeeping microcatheters stable in anterior cerebral artery (ACA) or middle cerebral artery (MCA) aneurysms during coil embolization is crucial in the success of the treatment. We currently use a triple...

Endovascular Management of Multiple Dysplastic Aneurysms in a Young Man with an Unknown Underlying Cause: A Case Report and Review of the Literature.

To explore the feasibility and effect of microsurgical treatment of complex intracranial aneurysms via keyhole approaches. Operation via keyhole approach was performed on thirty-one patients with 42 complex intracranial aneurysms were operated on, including 2 internal carotid artery bifurcation aneurysms, 1 anterior cerebral artery aneurysm, 12 posterior communicating artery aneurysms, 2 anterior choroids artery aneurysms, 7 middle cerebral artery aneurysms, 6 anterior communicating artery aneurysms, 2 basilar artery aneurysms, 2 vertebral artery aneurysms, 4 posterior cerebral artery aneurysms and 4 ophthalmic artery aneurysms, among which were 10 cases with multiple intracranial aneurysms, 14 with giant aneurysms, and 7 with posterior circulation aneurysms, and 4 aneurysms clipped by drilling off anterior clinoid process. Six of the 31 patients who had giant aneurysms came to hospital because of the symptoms, such as dizziness, headache, oculomotor paralysis, loss of vision, etc, and the other 25 patients were grouped according to the subarachnoid hemorrhage (SAH) Grade: 5 in grade I, 12 in grade II, 7 in grade III and 1 in grade IV. Eight patients were operated on after SAH in the early-phase, while 8 in the middle-phase and 9 in the late-phase. The supraorbital subfrontal keyhole approach was used 25 times, the pterional approach 5 times, the subtemporal approach 3 times, and both the suboccipital lateral approach and the retromastoid approach once. 31 of the 42 aneurysms were clipped, 2 mini-aneurysms wrapped, 5 giant aneurysms clipped and resected, 2 aneurysms trapped with thrombotic aneurysm partially resected, 1 aneurysm trapped, while 1 ruptured before operation and untreated. Short-term Glasgow outcome scoring showed good recovery in 27 patients, moderate disability in 2, and death in 2. Operation via keyhole approaches effectively controls the immature rupture of intracranial aneurysm, removes anterior clinoid process, respects giant aneurysm, and reconstructs the parent artery of wide-neck aneurysm. Based on individualized surgical approaches and excellent microsurgical skills, the complex intracranial aneurysms can be treated safely, directly and effectively via minimally invasive keyhole approaches.

It is important to prevent intraoperative aneurysm rupture in patients with ruptured cerebral aneurysms, because intraoperative bleeding can have catastrophic consequences. It is very useful for aneurysm surgeons trying to prevent this complication to know the incidence of intraoperative ruptures, the clinical grades and the location of aneurysms in which they occur and, when during operations intraoperative ruptures occur most frequently. We evaluated 905 of our patients with ruptured cerebral aneurysms and discussed the prevention of intraoperative rupture.Intraoperative aneurysm rupture was noted in 117 cases (13%). That rate was significantly higher in cases with middel cerebral artery aneurysms, anterior communicating artery aneurysms and anterior cerebral artery aneurysms than in those with internal cerebral artery aneurysms and vertebrobasilar artery aneurysms. The incidence was significantly higher in cases undergoing surgery on Day 0 to 3 and 8 to 14 than on Day 4 to 7 and after Day 15. The intraoperative bleeding rate was also significantly higher in cases with Hunt and Kosnik Grade III to V than in those with I to II. The rate of intraoperative hemorrhage was significantly lower in cases enduring temporary occlusion to prevent intraoperative bleeding than in those without temporary clipping. Over 90%of the intraoperative rupture occurred at the timing of aneurysm dissection and application of clips.Temporary clipping effectively prevents intraoperative bleeding. That should be followed by aneurysmal dissection with sharp microsurgical technique, when the intraoperative rupture may most likely occur due to the aneurysm tightly adhering to the surrounding tissues and its thinned and reddened wall. Especially, temporary clips should be used in clinical grade III to V patients with aneurysms in the anterior communicating artery, the distal anterior cerebral artery or the middle cerebral artery, who undergo surgery on Day 0 to 3 or Day 8 to 14.To avoid aneurysm rupture when retracting the frontal lobe, methods to decrease the retractor pressure should be devised. And the brain spatula should be pulled in the proper direction according to the position of aneurysms, involving the direction of aneurysmal domes, the location of blebs, and these possible adherence to the surrounding tissue. As insufficient dissection of the neck causes bleeding in clip application, it should be remembered that the aneurysmal neck must be sufficiently dissected from the surrounding tissue with temporary clipping. A wrapping aneurysm clip should be applied for a blister-like aneurysm in the anterior wall of the internal cerebral artery.