A giant unruptured middle cerebral artery aneurysm is a large, bulging area in the wall of one of the arteries in the brain, specifically in the middle cerebral artery, which has not yet burst or ruptured. Here's a breakdown of the key terms and concepts:
### Key Definitions
1. Giant Aneurysm: Aneurysms are classified based on their size:
2. Unruptured Aneurysm: An aneurysm that has not yet burst or leaked blood into the brain. Unruptured aneurysms may still pose significant risks, including growth leading to compression of adjacent structures or rupture resulting in a subarachnoid hemorrhage, which can be life-threatening.
3. Middle Cerebral Artery (MCA): The MCA is one of the major arteries that supply blood to the brain. It branches off the internal carotid artery and travels laterally into the lateral sulcus, providing blood flow to large portions of the lateral cerebral cortex, including areas that control movement, sensation, and speech.
### Characteristics and Implications of a Giant Unruptured MCA Aneurysm
- Location: Giant aneurysms in the MCA can occur at any segment of the artery but are most commonly found at bifurcations where the artery branches. The MCA is a critical artery as it supplies many functional areas of the brain.
- Symptoms:
- Risk of Rupture: Giant aneurysms have a higher risk of rupture compared to smaller ones, particularly if they are located in the posterior circulation or have certain characteristics such as irregular shape or presence of daughter sacs. Rupture of a cerebral aneurysm typically results in a subarachnoid hemorrhage, which can cause sudden, severe headache, loss of consciousness, and potentially death.
### Diagnosis
Diagnosis of a giant unruptured MCA aneurysm typically involves imaging studies such as:
- CT Angiography (CTA): A type of computed tomography scan that provides detailed images of blood vessels in the brain. - Magnetic Resonance Angiography (MRA): A type of MRI that focuses on blood vessels, giving a clear image of the aneurysm's size, shape, and relationship to nearby structures. - Digital Subtraction Angiography (DSA): An invasive procedure considered the gold standard for aneurysm diagnosis and evaluation, providing highly detailed images of the cerebral vasculature.
### Treatment Options
Treatment for a giant unruptured MCA aneurysm depends on several factors, including the aneurysm's size, shape, location, patient's age, overall health, and risk factors for surgery:
1. Observation: Small, asymptomatic aneurysms or those in patients with high surgical risk might be monitored with regular imaging to assess for growth or changes.
2. Surgical Clipping: Involves a craniotomy (surgical opening of the skull) to place a metal clip at the neck of the aneurysm, preventing blood from entering it and thus reducing the risk of rupture.
3. Endovascular Treatment: Less invasive than surgical clipping, this method involves threading a catheter through the blood vessels to the aneurysm site and placing coils (coil embolization), flow diverters, or stents to promote clotting within the aneurysm or divert blood flow away from the aneurysm sac.
4. Flow Diversion: Specifically for large or giant aneurysms, this involves placing a device within the parent artery that diverts blood flow away from the aneurysm, leading to thrombosis of the aneurysm while maintaining blood flow in the normal arteries.
### Conclusion
A giant unruptured MCA aneurysm is a serious medical condition that requires careful evaluation and management by a multidisciplinary team of specialists, including neurologists, neurosurgeons, and interventional neuroradiologists. The choice of treatment is highly individualized, aiming to prevent rupture and minimize neurological risks to the patient.
A study aimed to evaluate the postoperative outcome of patients with unruptured giant middle cerebral artery (MCA) aneurysm revealed by intracranial hypertension associated to midline brain shift. From 2012 to 2022, among the 954 patients treated by a microsurgical procedure for an intracranial aneurysm, our study included 9 consecutive patients with giant MCA aneurysm associated to intracranial hypertension with a midline brain shift. Deep hypothermic circulatory flow reduction (DHCFR) with vascular reconstruction was performed in 4 patients and cerebral revascularization with aneurysm trapping was the therapeutic strategy in 5 patients. Early (< 7 days) and long-term clinical and radiological monitoring was done. Good functional outcome was considered as mRS score ≤ 2 at 3 months. The mean age at treatment was 44 yo (ranging from 17 to 70 yo). The mean maximal diameter of the aneurysm was 49 mm (ranging from 33 to 70 mm). The mean midline brain shift was 8.6 mm (ranging from 5 to 13 mm). Distal MCA territory hypoperfusion was noted in 6 patients. Diffuse postoperative cerebral edema occurred in the 9 patients with a mean delay of 59 h and conducted to a postoperative neurological deterioration in 7 of them. Postoperative death was noted in 3 patients. Among the 6 survivors, early postoperative decompressive hemicraniotomy was required in 4 patients. Good functional outcome was noted in 4 patients. Complete aneurysm occlusion was noted in each patient at the last follow-up. We suggest discussing a systematic decompressive hemicraniotomy at the end of the surgical procedure and/or a partial temporal lobe resection at its beginning to reduce the consequences of the edema reaction and to improve the postoperative outcome of this specific subgroup of patients. A better intraoperative assessment of the blood flow might also reduce the occurrence of the reperfusion syndrome 1)