Single-center experience of endovascular treatment for patients with progressive posterior circulation cerebral infarction exceeding 24 h

Patients with progressive cerebral infarction caused by large vessel occlusion or extremely severe stenosis of the posterior circulation who were treated in the Department of Neurology at the Shenzhen Hospital of Southern Medical University from July 2017 to November 2018 were enrolled in the study. The patients whose NIHSS score increased >2 points after hospitalization were defined as progressive cerebral infarction. The study protocol was approved by the Ethics Committee of the Shenzhen Hospital of Southern Medical University (certificate of approval no. KY2017-048-01). The written informed consent was obtained from the patients. We have used the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines and The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) Statement [10, 11].

Magnetic resonance imaging (MRI) of the skull confirmed an acute cerebral infarction in the posterior circulation in all patients. Head and neck magnetic resonance angiography (MRA) or computed tomography angiography (CTA) identified large-vessel occlusion or extremely severe stenosis of the posterior circulation. Intraoperative angiography was performed to further determine and evaluate collateral circulation.

The treatment regimen followed the protocol of our previous study [12]. Briefly, large vessel occlusion of the posterior circulation was confirmed after angiography, and microguide wires and microcatheters were used to pass the lesion carefully to the distal vascular lumen. After the microcatheter was retracted, the vascular occlusion length was determined using micro-catheter angiography. A 1.5 mm gateway balloon was used to dilate the vascular lesion site, and then the reason of occlusion was analyzed by vascular morphology on microcatheter angiography. The vascular resistance during balloon dilatation, blood flow velocity, and blood flow volume with or without filling defect after balloon dilatation were measured. The operation was planned based on the medical history, risk factors, results of angiography, and resistance of microguide wires passing through the occlusion segment. If vascular stenosis was observed, a balloon of larger diameter was selected for expansion, and emergency stent implantation was performed when blood vessel dissection was found or the artery could not be recanalized after dilatation. Thrombectomy with retrievable stent placement was performed if thrombosis was suspected.

The preoperative NIHSS and modified Rankin Scale (mRS), postoperative complications, NIHSS and mRS at 3 months postoperatively. The patients were divided in to mRS score ≤2 and patients with mRS score >2, the related risk factors including age, gender, clinical characteristics, stroke subtype and occlusion site.

SPSS 17.0 statistical software was used for data analysis. The measurement data were subjected to the normality tests (Kolmogorov–Smirnov test), and data with a normal distribution are expressed as the means ± standard deviation (SD); non-normally distributed measurement data are represented by the median and quartile values (M [P25, P75]). Count data are represented by the number of cases. Measurement data with uniform variance were analyzed using t tests, and those with nonuniform variance were analyzed using t tests. A Chi-square test was used to analyze count data. P < 0.05 was considered statistically significant.

A total of 18 patients with progressive cerebral infarction caused by large vessel occlusion or extremely severe stenosis of the posterior circulation who were treated in the Department of Neurology at the Shenzhen Hospital of Southern Medical University from July 2017 to November 2018 were enrolled in the study.

The time from symptom onset to puncture ranged from 24.5 h to 3 weeks (average 163.5 h). The conditions of these patients were aggravated or relapsed repetitively after active drug treatment. The symptoms of 2 patients worsened after recombinant tissue plasminogen activator (rtPA) thrombolysis in other hospitals. The primary nervous symptoms and signs of the cerebral infarction progressively worsened, and NIHSS score increased to no less than 2 points [13].

Patients were classified according to the classification of the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) etiology as follows: 15 cases of major atherosclerosis, 1 case of cardiac embolism, and 2 cases of arterial dissection. Among them, 14 cases involved brain stem infarction lesions, 5 cases involved cerebellum infarction lesions, 4 cases involved occipital infarction lesions, and 2 cases involved thalamic infarction lesions. Twelve patients were male and 6 patients were female, their ages ranged from 39 years to 78 years (average age of 60.3 years). In addition, 14 patients (77.8%) had hypertension, 4 patients (22.2%) had diabetes, 2 patients (11.1%) had coronary heart disease, 2 patients (11.1%) had atrial fibrillation, 5 patients (27.8%) had dyslipidemia, and 5 patients (27.8%) had a history of smoking (Table 1).

In total, 11 cases demonstrated basilar artery stenosis or occlusion, including 4 cases complicated with unilateral vertebral artery stenosis or occlusion. Among the 11 cases, compensation of the basilar artery from the posterior communicating artery was found in 5 cases, that from the meningeal artery was found in 4 cases, and 2 cases had no collateral circulation compensation. Moreover, 3 cases demonstrated unilateral vertebral artery stenosis or occlusion without collateral circulation, and 4 cases demonstrated bilateral vertebral artery stenosis or occlusion, including 2 cases compensated by meningeal artery and 2 cases compensated by anterior spinal artery.

Three patients received balloon dilation due to large infarction areas in the brainstem (infarction lesions >1/3 of the same section level). A total of 9 patients underwent thrombectomy using a Solitaire AB/Trevo/Aperio thrombectomy stent. Among them, a Solitaire AB stent was released during operation in 5 patients, and 3 patients underwent balloon dilatation due to restenosis within stents because of thrombus. An intracranial balloon-expandable stent (Apollo) and a self-expanding stent (Winspan) were used in 1 patient due to a long segmental arterial lesion. Two peripheral SD stents were implanted in 1 patient due to long segmental vertebral artery dissection. Winspan stents were implanted in 7 patients, Apollo stents were implanted in 2 patients, and SD stents were implanted in 2 patients. The lesion arteries of all patients were recanalized after operation, and the modified thrombolysis in cerebral infarction (mTICI) [14] scale recovered to grade 3 in 14 patients and to grade 2b in 4 patients. Moderate to severe residual stenosis was found in 2 patients. Among these 2 patients, postoperative severe residual stenosis was found after stent implantation, and 50% residual stenosis was found even after expansion with a 2.5 mm balloon in 1 patient. The other patient underwent balloon dilatation due to a relatively large infarction area, and the residual stenosis was approximately 60%. Two patients underwent intra-arterial infusion of 10 mL of tirofiban solution during the operation, with intravenous pump infusion at 5 mL/h for 24 h after the operation. Residual stenosis of all the other patients was below 50% (Table 2).

In all, one patient died of basilar artery re-occlusion and pulmonary infection after the operation. One patient died of hemorrhage related to postoperative hyperperfusion. Furthermore, four patients had pulmonary infections, 2 of whom had preoperative NIHSS scores of 12 and 14, and their 3-month postoperative mRS scores were 3 and 5, respectively. The other 12 patients had no complications. The 16 patients who survived regularly took secondary preventive drugs (clopidogrel 75 mg/d, aspirin 100 mg/d, and Lipitor 20–60 mg/d). No recurrent cerebral ischemia events were observed in any of the 16 patients during the 3-month follow-up period. The mean mRS score was 1.3 (IQR: 2.3), and 75% patients (12/16) had an mRS score of 0–2. No aggravation of residual stenosis was identified.

Patients with posterior circulation progressive infarction had an average time from symptom onset to puncture of 163.5 h (25–528 h). The postoperative blood flow of all patients restored to mTICI grade 2b or above, and the 90-d mRS scores of 75% of the 16 survivors (12/16) were 0–2. A total of four patients with a 90-d mRS score of >2 had basilar artery occlusion (BAO) or severe stenosis (P = 0.0417; Table 3), including 3 patients with vascular lesions in the middle segment of the basilar artery and 1 patient with a vascular lesion at the tip of the basilar artery. The postoperative mTICI scores were all grade 3, the preoperative NIHSS scores ranged from 12 to 17, and skull MRI showed multiple infarction lesions in all 4 patients, including 1 case of bilateral cerebral peduncle and pons infarction, 1 case of bilateral thalamic infarction, and 2 cases of bilateral pons infarction. There were no significant differences in age, gender, clinical characteristics, and stroke subtype between patients with mRS scores ≤2 and patients with mRS scores >2 (P > 0.05).

In this article, we present a typical case who underwent emergency stent implantation after thrombectomy. The case was a 39-year-old woman admitted to the hospital due to “dizziness for 3 d.” Her physical examination showed a positive Romberg sign, and the skull MRI confirmed posterior circulation infarction attributed to occlusion of the V2 segment of the right vertebral artery. Thrombus was removed after thrombectomy with retrievable stent placement performed twice. Then, stents were implanted in the V2 segment because of dissection and the V3 segment because of severe stenosis. There was no residual stenosis after operation and no stenosis in stents after 3 months (Figure 1).

Figure 1.