Occult Brain Arteriovenous Malformation Superimposed on a Pial Arteriovenous Fistula: Case Report

<b><i>Introduction:</i></b> Pial arteriovenous fistulas are characterized by an abnormal connection between an intracranial artery and vein without an intervening nidus. Their predominant symptoms largely arise from mass effect, shunting, or hemorrhage. Most conservatively managed cases progress to death, but endovascular and/or surgical intervention is often successful. <b><i>Case Presentation:</i></b> We present the unique case of a 15-year-old girl with spontaneous intracranial hemorrhage from a single-vessel arteriovenous fistula. Although preoperative imaging failed to show a distinct nidus, intraoperative indocyanine green angiography performed after successful clipping of the primary fistulous site revealed residual shunting from a peri-lesional arteriovenous malformation. <b><i>Discussion/Conclusion:</i></b> This case demonstrates the importance of intraoperative imaging and meticulous circumferential inspection of these lesions to detect residual vascular shunting.

Traumatic dissecting pathology of posterior cerebral artery: a report of two cases—aneurysm and pial arteriovenous fistula

We present two cases of 17-year-old man and 10-year-old boy presenting with subarachnoid haemorrhage and a history of road traffic accident. One patient had dissecting aneurysm of the posterior cerebral artery (PCA), and the other patient had partially thrombosed aneurysm on CT angiography. On digital subtraction angiography of the second patient, there was formation of PCA pontomesencephalic vein pial arteriovenous fistula (PAVF). Both the patients underwent endovascular treatment: stent-assisted coiling for aneurysm and coiling with parent vessel occlusion for PAVF. There were no procedural complications. Follow-up angiography showed no residual aneurysm or fistula. Trauma is one of the recognised causes of dissection, and intracranial dissections can present as stenotic lesions, aneurysms or fistulas, depending on the pathology. Traumatic dissecting PCA aneurysm has been reported in only two case reports previously, and post-traumatic PAVF in PCA has not been reported.

De Novo Pial Arteriovenous Fistula Associated With Cerebral Infarction and Venous Hypertension: Report of 2 Cases Suggesting a “Second Hit Theory”

ABSTRACT BACKGROUND AND IMPORTANCE The etiology of de novo pial arteriovenous fistula (AVF) is unknown. We found 2 cases of de novo pial AVF, which appeared after cerebral infarction and which was associated with venous hypertension secondary to venous sinus thrombosis with a dural AVF (dAVF). Additional angiogenic stimuli (second hit) were considered as one of the mechanisms of de novo pial AVF. CLINICAL PRESENTATION A 63-yr-old male was admitted to our hospital due to an intraventricular hemorrhage. He had a history of cerebral infarction 2 yr before. Angiography demonstrated multiple dAVFs with bilateral occlusion of the distal transverse sinus associated with prominent retrograde cortical venous drainage. A pial AVF was found at the border of his previous cerebral infarction. Both lesions were successfully treated using endovascular technique. A second case involved a 47-yr-old female who was admitted to our hospital due to venous infarction also associated with sinus thrombosis. De novo pial AVF at the border of the venous infarction and dAVF at the transverse sigmoid junction were demonstrated on angiography 6 mo later. CONCLUSION We speculate that venous hypertension associated with additional angiogenic stimuli (second hit) due to brain ischemia and/or brain injury related to infarction caused de novo pial AVF in these 2 cases.

Endovascular Treatment of Intracranial Pial Arteriovenous Fistula in Paediatric Patient

Pial arteriovenous fistula (AVFs) are a rare, although clinically significant, vascular anomaly affecting the pediatric population, consisting of a high-flow connection between one or more pial arteries and the venous. In children, the clinical presentation varies according to age, can present with high output cardiac failure, macrocrania, neurodevelopmental delay, seizures, venous infarctions due to venous stenosis or hemorrhage secondary to venous thrombosis. The treatment, is a multimodal approach, most commonly endovascular, is effective in the obliteration of AVF. A case is presented of a previously healthy infant boy with neurological deficit arising from pAVF of the middle and posterior cerebral artery. The pAVF was successfully treated with endovascular occlusion.