Subacute and chronic cerebrovascular occlusion is an uncommon but an important cause for ischemic stroke.The main pathogenic mechanism is local hemodynamic disorder.Theoretically,the improvement of hemodynamic disorder can reduce the incidence of stroke as well as improve the prognosis.At present,there is still controversy over the optimal therapeutic plan.With the rapid development of interventional techniques,considerable progresses have been made in the endovascular treatment for subacute and chronic cerebrovascular occlusion,although some shortcomings still exist.This article aims to make a comprehensive review about the subacute and chronic cerebrovascular occlusion,focusing on its definition,damage,clinical status of its treatment,imaging evaluation,technical points of endovascular therapy,and procedure-related complications.

Objective To evaluate the mid-and long-term follow-up outcome of revascularization and stenting of nonacute intracranial vertebrobasilar artery occlusion. Methods Consecutive data of 27 patients who suffered from nonacute intracranial vertebrobasilar artery occlusion beyond 24 hours and underwent endovascular revascularization, were retrospectively collected and analyzed. Complications and recurrent ischemic events during the follow-up period were recorded. The modified Rankin scale(mRS) scores were used and compared between pre-and postoperation. Results All 27 patients except one(96.3%) obtained successful recanalization. After the procedure, 13 patients showed improvement, 11 were stable, and 3 worse. The decline of median mRS scores, which was 4(interquarter range-IR, 2-5) preoperatively and 3(IR, 1-5) on discharge. Five patients suffered from procedural complications and three of them resulted in aggravation. Nineteen patients received imaging follow-up during the median 10 months, 6 restenosis occurred and 3 of them were symptomatic. During median 55 months clinical follow-up after operation, 2 ipsilateral stroke and 2 ipsilateral transient ischemic attack occurred. The mRS scores decreased significantly in the first one year after procedure. Conclusions Revascularization and stenting of nonacute intracranial vertebrobasilar artery occlusion can prevent recurrent ipsilateral ischemic event and improve disability recovery in the first one year.

Objective:To explore the application value of three dimensional T 1 weighted sampling perfection with application-optimized contrasts by using different flip angle evolutions (3D T 1-SPACE) combined with three dimensional time of flight MR angiography (3D-TOF MRA) in the follow-up of stent-assisted coil embolization for intracranial aneurysm. Methods:From December 2017 to October 2018, 25 patients with intracranial aneurysm who underwent stent-assisted coil embolization in Henan Provincial People′s Hospital were enrolled. All of them had wide neck intracranial aneurysms and were followed up for 6 to 10 months after endovascular treatment using 3D-TOF MRA, 3D T 1-SPACE sequence and DSA. The DSA and 3D-TOF MRA were performed to evaluate aneurysm remnants using Raymond grade scale. Meanwhile, 3D-TOF MRA and 3D T 1-SPACE sequence were performed to evaluate in-stent lumen visibility using the 4-point scale. The paired sample Wilcoxon test was used to evaluate the aneurysm remnants and the parent artery patency. DSA was used as the gold standard to calculate the specificity and accuracy of the aneurysm remnants evaluated by 3D-TOF MRA. Results:Six to ten months′ follow up after the procedure, for aneurysm occlusion, the Raymond grade scale of the 25 patients evaluated by DSA indicated grade 1 in 23 patients, 2 in 1 and 3 in 1. For patients evaluated by 3D-TOF MRA, the results demonstrated grade 1 in 21 patients, 2 in 3 and 3 in 1. There was no difference between the 2 methods ( Z=-0.557, P=0.577). The in-stent lumens of parent vessel evaluated by 3D-TOF MRA showed that there were 14 patients with grade 3, 8 patients with grade 2 and 3 patients with grade 1. However, 3D T 1-SPACE demonstrated that all 25 patients were grade 4. The 3D T 1-SPACE was superior to evaluate the in-stent lumens than 3D-TOF MRA ( Z=-4.484, P<0.001). Taking DSA as standard, the specificity and accuracy of the aneurysm remnants evaluated by 3D-TOF MRA were 86.9% (20/23) and 84.0% (21/25), respectively. Conclusion:3.0 T 3D T 1-SPACE MR sequence can be used to assess parent artery patency, with in-stent lumen being clearly visible. 3D-TOF MRA can evaluate intracranial aneurysm remnants. The combination of these two MRI imaging techniques can be used as an optional follow-up evaluation after the endovascular treatment of intracranial aneurysms.

Objective:To compare procedural parameters and perioperative complications between the first-generation Pipeline embolization device (PED Classic) and the second-generation Pipeline embolization device (PED Flex).Methods:A total of 53 patients who underwent intracranial aneurysm treatment with the PED Classic from February 2015 to August 2016 and 118 patients who underwent treatment with the PED Flex from January 2018 to July 2019 at Zhengzhou University People's Hospital were enrolled in this retrospective study. Procedure time, contrast dosage, fluoroscopy time and perioperative complications in the two groups were recorded. Independent sample t-test was performed to analyze the difference of procedure time, contrast dosage and fluoroscopy time between the two groups, and Chi-square test was performed to analyze the perioperative complications. Results:There were 53 cases with 73 aneurysms in the PED Classic group and 118 cases with 146 aneurysms in the PED Flex group. The procedure time was (159.0±42.0) min in the PED Classic group, and (121.9±46.0) min in the PED Flex group. The difference was statistically significant ( t=5.012, P<0.001). The contrast dosage was (156.4±39.4) ml in the PED Classic group and (110.1±38.5) ml in the PED Flex group. The difference was statistically significant ( t=7.229, P<0.001). The difference of fluoroscopy time between PED Classic group and PED Flex group was also statistically significant ( t=10.196, P<0.001), with the average of (34.7±5.7) min and (22.8±7.6) min, respectively. The perioperative complications rate in the PED Classic group (9.4%, 5/53) was higher than that of the PED Flex group (2.5%, 3/118), but there was no statistical significance between the two groups (χ 2=2.503, P=0.114). Conclusion:The use of PED Flex seems safe in treating intracranial aneurysms, and the device deployment is easier compared with the use of PED Classic. However, serious complications remain to be noted.

Objective To evaluate the feasibility of transvenous embolization treatment for cerebral arteriovenous malformations(bAVM). Methods From November 2016 to April 2017, the information of 6 patients with brain arteriovenous malformation in our center accepting the intravenous radical embolization were collected, who were ruptured bAVM, bAVM with a single drainage vein, not suitable for surgery confirmed by neurosurgeon consultation or explicitly refused craniotomy. The modified Rankin Scale score of five patients were smaller than three before treatment.The location of draining vein flowing venous sinus was shown by rotational DSA and 3D reconstructed images.A liquid embolic agent was injected via Sonic catheter to completely embolism the brain arteriovenous malformation under controlling blood pressure and blocking the blood provisionally.The perioperative complications and modified Rankin Scale score were observed and recorded 30 days after treatment. Results The transvenous embolization treatment was successfully performed in six patients with 7 embolization procedures.There were no definite operation-related complications. the mRS of all cases were ≤1 within 30 days after operation. Conclusion The embolization technique via the internal jugular vein is feasible for bAVM patients with a single drainage vein,while the long-term outcome need more evaluations.