| Background and Objective:Acute Ischemic Stroke (AIS) is the clinical event caused by acute circulatory disturbance of the stem or cortical cerebral artery. This disturbance leads to ischemia-hypoxia of brain tissue, rapid local or diffuse brain function impairment. AIS possesses the characteristics of acute onset, high disability rate and mortality. It greatly threatens the human health and brings heavy economic burdens to families and society. The treatment priority is to start the vascular recanalization of occluded brain vessels in the shortest time, improve the brain ischemia-hypoxia quickly, recover brain function in the ischemic penumbra maximumly, and reduce the disability and mortality of stroke. Time is life, and the thrombolytic therapy in the super-early stage has been sufficiently proved by evidence-based medicine and already been used and popularized in clinical application for more than10years. In spite of this, there is restriction of therapeutic time window in thrombolysis no matter in the vein and artery. The4.5-hour time window for vein thrombolysis is so short that most of the patients delay the "prime time" and hence miss the treatment time. Even in the developed countries like America, only2%to3%patients get the chance to receive intravenous thrombolysis treatment. Although the time window of artery thrombolysis treatment can be lengthened to6hours, the artery intubation itself will delay the time of drug administration and the incidence of symptomatic intracranial hemorrhage will gradually increase. Therefore, the patients who really profit from this treatment are minority. Intravascular mechanical therapy (IMT) is gradually emerging in recent years. Mechanical fragmentation and embolectomy by-stents are the two effective methods to treat AIS nowadays. Partially unorganized thrombus can be comminuted by the mechanical push and pull through micro guidewire and microcatheter and also the cutting action by stent meshes. The function of mechanical fragmentation is to smash the thrombus tissue, accelerate the vascular recanalization of occluded vessels, and enlarge the contact area of thrombolytic drug and the thrombous. The drugs that pumped into the vessels after mechanical fragmentation may act on the crumbling thrombus and prevent the thrombus residue and the incidence of secondary cerebral embolism. Embolectomy by stent may directly take most of the thrombus tissue out of the body, which can not only regain blood flow of the blocking vessel as quickly as possible, shorten the vascular recanalization time, but also greatly reduce the dosage of thrombolytics, decrease the incidence of intracranial hemorrhage caused by those drugs. Roth etc reported the mechanical fragmentation by use of Solitaire AB (ev3Inc,Plymouth,MN) stent.90.9%blocked vessels were effectively reopened and the mean reopen time was (277±118) mins. Their research gained a satisfactory outcome. Castan etc researched the curative effect of AIS patients by use of Solitaire and got a vascular recanalization rate of90%with an average treatment time of50mins while no adverse event related to embolectomy happened. Solitaire AB Stent is a kind of recyclable self-expanding nitinol stent. The Solitaire AB Stent with a diameter of4mm and6mm is commonly used currently in clinical. Therefore, the vessels suitable for treatment by stent are those with diameter from2.0mm to5.5mm. The blocked intracranial vessels with diameter less than2mm can’t be taken out by stent. However, the mechanical fragmentation by microcatheter can be used to the blocked intracranial vessels with diameter less than1mm. So both mechanical fragmentation and embolectomy by stent have their advantages and disadvantages. However, little has been reported about the comparison between the two treatment methods. In this study, we comparatively analyzed the efficacy and safety of AIS treatment through two methods-mechanical fragmentation and embolectomy by stent. The study aimed to offer objective reference in clinical practice for the treatment of AIS patients, which has important value in theoretical significance and clinical value.Methods and materials:82patients with acute cerebral arterial occlusion were retrospectively collected from May2010to December2013. Of the80patients,44were male and33female. Their ages were from33years to85years with a mean age of61years. According to the treatment,58patients were given mechanical fragmentation by microcatheter combining with intra-arterial thrombolysis, while24patients were given embolectomy by Solitaire AB Stent combing with intra-arterial thrombolysis. The onset time of both groups were in3-5hours. Cerebral angiography (DSA) through femoral artery puncture with local anethesia was used in both groups to clear the responsible vessel and blocking area, possible intracranial and extracranial collateral circulation. In mechanical fragmentation group with58patients,35cases were diagnosed with middle cerebral artery main stem occlusion,17cases with cross portion of terminal internal carotid artery occlusion,2cases with anterior cerebral artery occlusion and4cases with main stem of vertebro-basilar artery occlusion. While in embolectomy group with24patients,14cases were diagnosed with middle cerebral artery main stem occlusion,6cases with cross portion of terminal internal carotid artery occlusion,1case with anterior cerebral artery occlusion and3cases with main stem of vertebro-basilar artery occlusion. The guidewire of Progreat Microcatheter System (2.7F) was used in the embolectomy group. The catheter mechanically acted on and fragmented the thrombus, and then catheter-directed thrombolysis was operated by the microcatheter. In embolectomy, the Solitaire AB Stent (Size:4mm×15mm or6mmx20mm) was placed in the blocked artery. In the state of stent naturally open and Y valve bypass, the thrombus was taken out through repeated withdrawals of stent. Finally the residual thrombus would be found by Y valve bypass withdrawal. Urokinase was used for thrombolysis in both groups. It was pumped in a constant speed (10,000unit/min) and microcatheter would send it to thrombus in targeted vessel. Radiography was used to recheck the blood flow of blocking part. Treatment would be over if forward blood flow had reached TICI2-3grade. Postoperative treatment was the same in both groups:subcutaneous injection of Low Molecular Weight Heparin Calcium for3days, oral administration of Bayaspirin100mg/day, anti-platelet therapy by taking Plavix75mg/day and nerve protection by using Edaravone, and so on. After treatment, all patients would get skull CT scan in three days to know if the range of cerebral infarction enlarged or there was secondary cerebral hemorrhage. Thrombolysis in Cerebral Ischemia Grade (TICI) was chosen to make haemodynamics assessment of forward bloodstream classification. TICI2-3grade proves successful revascularization while TICI0-1grade proves failed. National Institutes of Health Stroke Scale (NIHSS) was used to evaluate the severity of cerebral stroke before and3days after operation. Vascular recanalization and complication rate after operation were calculated. Vascular recanalization rates of the two groups were statistically analyzed by SPSS10.0software. We applied the Paired Sign Rank Sum Test Method to compare NIHSS before and after treatment in each group. P<0.01believes that there is a statistically significant difference. While the Rank Sum Test for Two Independent Samples was used to compare NIHSS before and after treatment between the two groups. P<0.05believes that there is a statistically significant difference. Then Chi Square of Two Independent Sample Rate Test was applied to compare the vascular recanalization rates of two groups. P<0.05believes that there is a statistically significant difference.Result:The vascular recanalization was81.0%in group treated with mechanical fragmentation while83.3%in group treated with embolectomy. Comparing the recanalization rates of the two groups, no statistically significant difference was found (P>0.05). In the group with mechanical fragmentation,39cases got completely recanalization (TICI3class),8cases partially (TICI2class) and11cases failed (TICI0-1class). Recanalization in middle cerebral artery main stem was100%(35/35), cross portion of terminal internal carotid artery35.3%(6/17).2case got totally recanalization in anterior cerebral artery,4cases in stem of vertebro-basilar artery.1patient gave up treatment because the micro guidewire failed to go through blocked cross portion of internal carotid artery.2patients suffered from secondary cerebral hemorrhage (3.45%).1patient suffered from coma during treatment and then was sent to ICU for decompression by drilling and drainage the intracranial hematoma, but finally died after ineffective rescue.2cases (3.45%) got sencondary cerebral embolism due to the fall off of thrombus fragments but the patient suffered no progressive symptom compared with pre-operation. In the embolectomy group,17cases got completely recanalization (TICI3class),3cases partially (TICI2class) and4cases failed (TICI0-1class). Recanalization in middle cerebral artery main stem was100%(14/14), cross portion of terminal internal carotid artery50.0%(3/6).1case got totally recanalization in anterior cerebral artery,2cases in stem of vertebro-basilar artery.1patient with thrombus in cross portion of internal carotid artery suffered from embolism in anterior cerebral artery and middle cerebral artery main stem after embolectomy by stent, which led to secondary cerebral embolism. The radiographic blood flow recheck showed TICI0class, failed recanalization.The comparison between two groups of patients with preoperative NIHSS shows no statistically significant difference (P>0.01). Postoperative NIHSS also shows no statistically significant difference (P>0.01). In the group with58cases got mechanical fragmentation, the NIHSS in3days after treatment was5.0±3.6, which was obviously lower than the scores before treatment(13.8±2.1).In the group with24cases got embolectomy by stent, the NIHSS in3days after interventional therapy was4.0±3.6, which was obviously lower than the scores before intervention (13.1±2.0).The complications of mechanical fragmentation and embolectomy by stent for ischemic stroke include symptomatic intracranial hemorrhage, secondary cerebral embolism, aortic dissection, arterial perforation, cerebral blood flow reperfusion injury, and so on. In this study, a85-year-old patient suffered from secondary cerebral hemorrhage and rapid coma during treatment. Although treated by drilling and drainage the intracranial hematoma, the patient finally died.2cases suffered from secondary cerebral embolism but there was no progressive performance of neural symptoms. In the embolectomy group, there was no asymptomatic intracranial hemorrhage.1patient with thrombus in cross portion of internal carotid artery suffered from secondary cerebral embolism after treatment but there was no progressive performance of neural symptoms. In both groups, there was no severe complications such as aortic dissection, arterial perforation, etc.Conclusion:Compared with the curative effect for AIS, there was no significant differences between the two groups:embolectomy by stent and mechanical fragmentation by microcatheter. There was no severe complication like asymptomatic intracranial hemorrhage in patients receiving embolectomy by stent, which affirms the clinical efficacy and safety of embolectomy. But the operation is relatively complex and it requires higher equipment conditions and technical staff. The recanalization success rate in mechanical fragmentation group was not lower than that of embolectomy group. In clinical operation, the mechanical fragmentation technique is easier for application.In clinical, we should choose a suitable treatment method according to the site of blocking vessel, disease time, the economic situation of patients so that we will make the clinical practice more objective and scientific.The stroke types and clinical experience of the operating physician are key factors to affect success and complications. |
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