They suggested that thromboembolism due to coil loop herniation into the PICA origin and occlusion of a perforating artery was possible causes of the PICA territory infarction. Although PICA has rich pial anastomoses, there have been case reports of PICA infarction on follow up images after endovascular procedure. In one case, there was lateral medullary infarction 2 days after internal trapping. Only one case revealed recanalization of the dissecting aneurysm after 1 year, which was retreated with internal trapping ( Fig. In our study, clinical and radiologic results were satisfactory in upruptured patients treated with internal trapping and stent placement with or without coils. This technique, as well as parent artery occlusion, show favorable results in unruptured VADA cases according to several reports. Reconstructive techniques, stent placement with or without coil embolization, aims at the preservation of the vertebral artery flow. For making a decision of parent artery occlusion in cases of unruptured VADA, there are several factors to be considered: risk of bleeding in conservative treatment risk of ischemic complications during procedure blood supply from the anterior and posterior spinal artery, perforating arteries, and patency of contralateral vertebral artery and relationship between aneurysm and PICA. Risk of bleeding from unruptured VADA was higher than previous reports and endovascular treatment should be considered in some cases, such as in cases of increased size of aneurysmal dilatation during follow-up period and when double lumen sign is visible in the acute stage. Administration of antiplatelet or anticoagulant in patients with unruptured VADAs and ischemic presentations may exacerbate aneurysmal dissection and cause rupture of the aneurysm. 1).Īlthough unruptured VADAs usually show benign clinical course, the natural course of the unruptured VADAs is still unknown and treatment guideline remains controversial. In our case, there was one ruptured VADA case which showed antegrade recanalization 6 months after internal trapping ( Fig. Detachable coils were insufficient to cover the entry of the dissecting aneurysm. The mechanism of the antegrade recanalization can be explained as following (1) if microcatheter navigate into the false lumen and occlude the false lumen with detachable coils, true lumen dilates into the normal diameter as false lumen collapses (2). However, there were several case reports of antegrade recanalization after endovascular treatment for ruptured VADAs. Multiple studies regarding direct occlusion of the pathologic segment were reported. First, deconstructive techniques can be performed by balloon or coil embolization. Two main concepts in the endovascular treatment of the VADA are deconstructive and reconstructive techniques for the parent vessels. Endovascular intervention is mandatory to prevent these fatal rebleeding. Ruptured VADA shows high incidence (over 70%) of rebleeding within 24 hours which results in poor clinical outcome. SAH occurs due to rupture of the thin layer of intradural adventitia. After disruption, leukocyte and macrophage infiltration, endothelial coverage, and neointima formation follow subsequently. Primary mechanism of the arterial dissection is disruption of the internal elastic lamina. Favorable outcome (mRS 0 and 1) was achieved in 5 patients and poor outcome in 8 patients. Follow-up mRS was available in 13 patients. There were 6 procedure-related complications: lateral medullary infarction (n=2), embolic infarction (n=2), unintended arterial occlusion (n=1), and parent artery dissection (n=1). In 2 cases treated with stent-assisted coil embolization, follow up imaging studies showed no change in 1 case and complete occlusion with vessel remodeling in 1 case ( Fig.

Follow up imaging study in 7 cases treated with internal trapping revealed complete occlusion in 6 cases and antegrade recanalization in 1 case ( Fig. Immediate angiographic results revealed complete occlusion in 14 cases and incomplete occlusion in 3 cases. In ruptured cases (n=17), endovascular treatment consisted of internal trapping with coil embolization (n=13) and stent-assisted coil embolization using self-expandable stent (n=4). Results of immediate and follow up imaging studies in ruptured VADAs are presented in the table. Of 17 ruptured VADAs, 5 cases initially presented with poor grades (4 or 5), 8 cases with grade 3, 2 cases with grade 2, and 1 patient with grade 1.

Pica artery dissection survival