Pure arterial malformation with associated aneurysmal subarachnoid hemorrhage: Two case reports and literature review / 中南大学学报(医学版)

In recent years, in the absence of venous component, dilated, overlapping, and tortuous arteries forming a mass of arterial loops with a coil-like appearance have been defined as pure arterial malformation (PAM). It is extremely rare, and its etiology and treatment have not yet been fully elucidated. Here, we reported 2 cases of PAM with associated aneurysmal subarachnoid hemorrhage in this paper. Both patients had severe headache as the first symptom. Subarachnoid hemorrhage was found by CT and computed tomography angiography (CTA) and PAM with associated aneurysm was found by digital subtraction angiography (DSA). In view of the distribution of blood and the location of aneurysms, the aneurysm rupture was the most likely to be considered. Based on the involvement of the lesion in the distal blood supply, only the aneurysm was clamped during the operation. It used to be consider that PAM is safety, because of the presentation and natural history of previously reported cases. Through the cases we reported, we have doubted about "the benign natural history" and discussed its treatment. PAM can promote the formation of aneurysms and should be reviewed regularly. The surgical indications for PAM patients with aneurysm formation need to be further clarified. Management of PAM patients with ruptured aneurysm is the same as that of ruptured aneurysm. Whether there are indications needed to treat simple arterial malformations remains to be further elucidated with the multicenter, randomized controlled studies on this disease.

Variations in the brain circulation: the circle of Willis

Introduction: Despite being quite common, there is little information concerning the Brazilian population on anatomic variations and anomalies in the brain circulation. This study intends to describe the most common variations found during the autopsies for the AMA Study. Material and methods: Fifty cadavers had their circle of Willis dissected and analyzed. Results: 54% presented at least one variation, and they were more common in the posterior circulation (88.5%) and on the right side of the brain (59.7%); non-classical morphology was more common bilaterally and in the posterior circulation of the circle of Willis (37.1%). The most common finding was the absence of the posterior communicating artery (32%), followed by posterior cerebral arteries originated from the internal carotid artery (18%). There were no variations in the middle cerebral arteries. Accessory anterior cerebral arteries were present in 6%, and A1 segment hypoplasia was present in only 2% of the cases. Conclusion: Brazilian population variations are in accordance with the literature and there seems to be no difference between races in the variation of brain circulation.

Variations in the anatomy of the coronary arteries

Even though anatomic variations in the cardiac circulation are quite common, there is littleinformation concerning the Brazilian population. This study intends to describe the most common variationsfound during the autopsies for the AMA Study. Material and methods: fifty human cadavers had theirhearts were dissected and analyzed. Results: variations occurred in 64% of all cases and were more commonin the posterior circulation (40.6%); arterial hypoplasia was present in 14% of the circumflex arteries, 12% ofthe marginal arteries; duplication of the posterior interventricular artery occurred in 2%; muscular bridgesoccurred in 4%; anomalous origin of arteries occurred in 14% in total; right dominant pattern was presentin 88%, left dominant in 8%, and undetermined in 4%. Conclusion: Brazilian population variations are inaccordance with the literature; anatomic variations of the heart arteries are common; and there seems to be nodifference among different populations.