Stereotactic angiographic localization as an adjunct to surgery of cerebral mycotic aneurysms: case report and review of the literature

Infectious intracranial aneurysms: a systematic review of epidemiology, management, and outcomes

Infectious intracranial aneurysms (IIAs) are a rare cerebrovascular complication of systemic infections induced by microbial infiltration and degradation of the arterial vessel wall. Studies on the epidemiology and management of IIAs are limited to case reports and retrospective single-center studies, and report a large variability in epidemiological features, management, and outcomes due to the limited sample size. We conducted a systematic review of all published papers on IIAs in the English literature using MEDLINE and SCOPUS database from January 1950 to June 2017. A total of 288 publications describing 1191 patients with IIA (1398 aneurysms) were included and reviewed for epidemiological features, disease features, treatment and outcome. All patients were merged into a single cohort and summary data are presented. The majority of reported IIAs are distally located, relatively small (<5 mm), involve the anterior circulation, are associated with a relatively high rate of rupture, and demonstrate a propensity to multiplicity of aneurysms. Sensitive diagnosis of IIAs requires digital subtraction angiography and not CT angiography or MR angiography. Treatment of ruptured, symptomatic, or enlarging IIAs has evolved over the last 50 years. Endovascular therapy is associated with a high success rate and low morbidity compared with microsurgical and medical management. A treatment algorithm for the management of patients with IIA in various contexts is proposed and the need for prospective multicenter studies is emphasized.

Endovascular Treatment for a Unusually Large Mycotic Aneurysm Manifesting as Intracerebral Hemorrhage-Case Report-

A 62-year-old male presented with an unusually large mycotic aneurysm mimicking a saccular aneurysm manifesting as coma and hypotension. Computed tomography showed intracerebral and intraventricular hemorrhage. He was in septic shock due to acute infectious endocarditis. Cerebral angiography disclosed a large distal anterior cerebral artery aneurysm. The diagnosis was mycotic aneurysm based on the morphological features and associated endocarditis. The aneurysm and the parent artery were successfully occluded by endovascular embolization. High-dose antibiotic therapy in the following 6 weeks resulted in resolution of the infectious endocarditis. Early exclusion of ruptured mycotic aneurysm is mandatory because of the high risk of rerupture. Endovascular treatment is an effective alternative for mycotic aneurysms, especially if the patient's general condition is poor. Parent artery occlusion can be safely tolerated if the aneurysm is located distally.

Evaluation of a distal pericallosal aneurysm visualized with 3-dimensional digital subtraction angiography: case report and treatment implications

BACKGROUND

Digital subtraction angiography (DSA) is considered the gold standard in the evaluation of cerebrovascular structures. Recently, 3-dimensional DSA (3D-DSA) has been increasingly used to obtain detailed information about the morphology and dimensions of intracranial aneurysms. We report the case of a patient who presented with a distal pericallosal artery aneurysm, which appeared by 2D imaging to be a fusiform, possible mycotic aneurysm. This was then revealed to be a saccular bifurcation aneurysm by 3D-DSA. This additional information changed the treatment plan for this patient from medical management to a surgical approach.

CASE DESCRIPTION

The patient is a 56-year-old man with a history of hypertension and alcohol abuse with withdrawal seizures, who presented with a large intracranial hemorrhage on initial computed tomography scan. After stabilization with intracranial pressure management, the patient underwent magnetic resonance angiography and 4-vessel DSA. These initial studies showed a distal, fusiform pericallosal aneurysm consistent with a mycotic aneurysm. Rotational DSA was then used to generate 3D images of the structure that revealed a saccular bifurcation aneurysm. This enabled the decision to offer operative treatment rather than conservative medical management.

DISCUSSION

This report highlights the value of 3D-DSA in establishing the appropriate treatment plan for patients with unique cerebral aneurysms. The higher resolution images used in this case provided information that was crucial in shifting the treatment focus from medical management, for what appeared to be a mycotic aneurysm by traditional DSA, to surgical intervention, for a clear hemodynamic aneurysm at a vessel bifurcation seen with 3D-DSA. Accurate pre-interventional evaluation and differential diagnosis are critical to designing the most effective lowest risk treatment plan. The standard method in the diagnosis of cerebral aneurysms has been DSA. Yet, higher resolution images of unclear or high-risk aneurysms are often required to guide clinical decision making. The emergence of new, less invasive endovascular techniques for securing intracranial aneurysms has placed greater emphasis on precisely defining the shape and dimensions of an aneurysm. Three-dimensional DSA is currently the highest resolution imaging modality available for the evaluation of intracranial aneurysms.

CONCLUSION

3D-DSA was used to evaluate a small, distal pericallosal artery aneurysm and revealed a saccular bifurcation aneurysm not visualized with magnetic resonance angiography and conventional DSA. This additional resolution permitted the team to consider a surgical approach for a patient who would otherwise have been treated medically. This high-resolution technique is particularly useful in guiding clinical decision making in the context of aneurysms that carry a relatively broad differential diagnosis, potentially high interventional risk, and unclear morphology.

Endovascular treatment of cerebral mycotic aneurysms

PURPOSE

To evaluate the endovascular treatment (EVT) of mycotic aneurysms (MAs).

MATERIALS AND METHODS

Clinical and radiologic data of 18 MAs treated with EVT were retrospectively reviewed. There were 14 patients (11 men, three women), ranging in age from 28 to 64 (mean age, 44 years). All patients had endocarditis and positive blood culture. The aneurysms were located within the distal cerebral circulation (n = 13) or in the circle of Willis (n = 5). There were 12 ruptured aneurysms and six unruptured aneurysms. Distal or fusiform aneurysms were treated by means of parent vessel occlusion. Proximal saccular aneurysms were selectively treated.

RESULTS

Endovascular treatment was successful for all aneurysms. No aneurysm bled after embolization during clinical follow-up. Follow-up angiograms obtained in 11 of 14 patients 6 months to 2 years after the procedures showed stable occlusions. Transient complications occurred in two cases, with worsening of hemiparesis and quadrantanopia. Five patients underwent surgical cardiac valve replacement within 1 week of EVT without neurologic complications. The late clinical outcome was normal neurologic status (n = 9) or permanent disability that was related to the initial stroke (n = 5).

CONCLUSION

EVT is a reliable and safe technique that should be considered at the time of diagnosis of cerebral mycotic aneurysms.

Distal anterior choroidal artery aneurysm in a patient with moyamoya disease: case report

OBJECTIVE AND IMPORTANCE

Distal anterior choroidal artery (AChA) aneurysms in moyamoya disease are rare, with few surgically verified reported cases.

CLINICAL PRESENTATION

We report a rare case of distal AChA aneurysm associated with moyamoya disease in a 48-year-old man who presented with vomiting and severe headache. Computed tomographic scans revealed an intracerebral hematoma in the right temporoparietal lobe and a diffuse intraventricular hemorrhage.

INTERVENTION

The hematoma was removed via computed tomography-guided stereotactic aspiration and ventricular drainage. Cerebral angiography showed a saccular aneurysm located at the distal branch of the right AChA. By means of magnetic resonance imaging, a small signal void lesion was detected in the periventricular area lateral to the trigone of the right lateral ventricle. The aneurysm was accurately accessed via a parietal cortical incision by use of magnetic resonance imaging-guided stereotactic localization. The aneurysm was successfully resected after undergoing trapping of the parent artery, and when the patient was discharged, he had no evidence of neurological deficit. The aneurysm was histologically verified to be a true aneurysm.

CONCLUSION

Direct surgery should be considered in cases of ruptured distal AChA aneurysms located in the periventricular or intraventricular regions.