Predictive Factors Of Rehemorrhage After Endovascular Treatment Of Ruptured Intracranial Aneurysms

BackgroundIntracranial aneurysm is a vascular disease characterized by local ballooning of an intracranial artery, mainly occurred in the cerebral arterial circle and its major branches. The rupture of a intracranial aneurysm usually results in internal bleeding such as a subarachnoid hemorrhage and intracranial hematoma, which often leads to death. In the etiology of cerebral vascular disease, the incidence of intracranial aneurysms is very high, immediately after intracranial thrombosis, hypertensive intracerebral hemorrhage. Intracranial aneurysms mainly occurred in the population aged40-60, the peak onset is around50years old which account for about2/3or more, while the youth is relatively rare. Mayo Clinic reported that the morbidity of aneurysm is about3.6%-6%, while the rupture rate is about1%-2%. Eighty-five percent of SAH is caused by the rupture of intracranial aneurysms. According to statistics data, the prognosis of aneurysm is very poor. In patients who suffered the first rupture, about15%-20%of patients could not receive timely treatment and died outside the hospital. Moreover,50%patients left with severe neurological dysfunction, such as aphasia, blindness, disability, etc. Awareness of aneurysm has been further improved with the development of science as well as in-depth understanding of the aneurysm. However, its specific pathogenesis is remaining inconclusive. The aneurysm was coursed by the following reasons:vascular factors, including atherosclerosis, Willis ring variation caused by congenital or acquired; hemodynamic factors, the changes of blood flow can lead to vascular degeneration, and change the status of the blood flow, finally, leads to the vascular lesions; exogenous factors, including trauma (traumatic pseudoaneurysm), infections (infectious aneurysm), tumors, drug-induced factors. Studies have shown that about90%of aneurysms occurred in the brain other than the bottom Willis artery cycle and its major branches. Large-scale clinical studies showed that the anterior communicating (AcomA) and posterior communicating artery (PcomA) aneurysm accounted for30%-35%, the middle cerebral artery aneurysms account for about20%. According to the clinical study of Zhujiang Hospital, Southern Medical University, the posterior communicating artery aneurysms account for40.75%, anterior cerebral artery aneurysms account for22.09%, anterior communicating artery aneurysm accounting for10.17%, middle cerebral artery aneurysms accounted for5.05%, and the remaining21.94%located in the basilar artery and other locations, such as primitive trigeminal artery, cervical internal carotid artery. Therefore, it is very important to choose the right therapeutic strategy for different aneurysms. The treatment of intracranial aneurysms has two treatment strategy, traditional craniotomy and endovascular treatment. The former includes aneurysm neck clipping surgery and aneurysm isolated parcels surgery and so on. However, due to the higher risk and higher skill requirements of traditional craniotomy surgery, it is carried out only in the domestic clinical neurosurgery skilled hospitals. Most recently, the results of the International Subarachnoid Hemorrhage Trial (ISAT) demonstrated the clinical superiority of endovascular treatment to standard surgical management of ruptured intracranial aneurysms. However, it is more likely that aneurysm remnants and recurrences are more frequent after coil placement than after surgical clipping, although reports of surgical series with follow-up angiography are scarce. A main concern with EVT is the possibility that the aneurysm will reopen after coil placement, which exposes patients to the risk of hemorrhage. There are three kinds of endovascular technique for the treatment of intracranial aneurysm coil embolization: simple coil embolization, balloon-assisted embolization and stent-assisted coil embolization. However, none of them could guarantee to completely prevent embolised aneurysm from recurrence or rebleeding. In endovascular coil embolization of intracranial aneurysms, it is known to be important to pack coils as tightly as possible to avoid recanalization, and incomplete embolization is one of the major risk factors for recanalization. Although it could not guarantee to completely prevent embolised aneurysm from recurrence or rebleeding. However, compared to simple coil embolization alone, it has been a marked improvement, which has become a very important and effective method for the treatment of aneurysms. The mechanism of the low recurrent rate after stent-assisted endovascular treatment may be due to the following reasons. First, the stent could narrow the neck of the aneurysm, consequently prevent coil from protruding into the parent artery and reduce the impact zone, thus weaken the impinging force exerted on the coil mass and thereby reduce coil compaction. Second, the stent produces flow redirection by reducing the curvature of the parent vessel. Subsequently, the flow within the aneurysm and the parent vessel becomes disordered, which should promote aneurysm thrombosis, decrease the wall shear stress on and subsequent growth of any portions of the aneurysm that remain untreated. This may further discourage aneurysm regrowth. Finally, the stent provides a physical matrix for endothelial growth, facilitating the remodeling of the aneurysm neck as well as the parent vessel in the region of the aneurysm neck. However, the specific mechanism is inconclusive. Despite all the advantages of endovascular treatment, the frequency of aneurysm recurrence after coil embolization is higher than that after clipping. Aneurysm recurrence is the main factor influencing the efficacy of endovascular coil embolization, which was reported at a rate of17.4%. The development or enlargement of an aneurysm neck/sac remnant after coiling is the main imaging manifestation of aneurysm recurrence. Overall, although the recanalization rate of endovascular treatment was higher, the rate of rebleeding after embolization is low. Early rehemorrhage was associated with high mortality and morbidity, was the most dangerous complication of embolization. For ruptured intracranial aneurysms, the purpose of craniotomy clipping surgery and interventional endovascular treatment is to try to prevent rebleeding and other complications. Most of the literature defined early rebleeding as a month, and also1week,3months or1year. In this study, we set1month as the time limits between the early and delayed rebleeding. According to the latest findings, the rate of early rehemorrhage for ruptured intracranial aneurysm after endovascular treatment is0.9～3.6%. And the rate of late rehemorrhage was less than1.0%, far less than the recanalization rate, however, it will endanger the lives of patients.ObjectiveThe paper mainly investigated the incidence, risk factors of early and late rehemorrhage of ruptured intracranial aneurysms after endovascular treatment and illustration of our empirical prevention and management on this event.MethodsBetween January2002and January2014, consecutive endovascular embolizations with platinum coils for1455patients with ruptured intracranial aneurysms were performed in Interventional Therapy Centre, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University. We retrospectively reviewed their clinical records and images, and analysis risk factors of rehemorrhage by using multivariate logistic regression. The following characteristics were recorded:age, sex, hypertension, location and size, wide-neck or not, aneurysm shape, ruptured times of aneurysms before endovascular treatment, patient’s initial clinical condition, ICH adjacent to the ruptured aneurysm, obvious intracranial vasospasm, aneurysm occlusion grade, anticoagulant therapy, obviouse fluctuation of blood pressure after treatment, time cell between first endovascular treatment and rehemorrhage, clinical outcome(mRS grade), therapeutic strategy after rehemorrhage. Rehemorrhage was diagnosed if the CT scan revealed an increased amount of hemorrhage when compared with the immediate post-procedural CT scan. We divided rehemorrhage into early and late groups depending on the timing of rehemorrhage after endovascular treatment. Early rehemorrhage was defined as occurrence of further bleeding within30days after coiling. Late rehemorrhage was defined as recurrent hemorrhage from a coiled aneurysm>1month after coiling. All patients treated with coil embolization underwent a CT scan immediately following the procedures and again whenever clinical deterioration was observed. Rehemorrhage was diagnosed if the CT scan revealed an increased amount of hemorrhage when compared with the immediate post-procedural CT scan. Those who showed delayed deterioration after recovery from anesthesia were also included if the bleeding amount increased on follow-up brain CT compared to initial brain CT. Data were analyzed with the SPSS statistical package (SPSS13.0). Data are presented as mean and range for continuous variables, and as frequency for categorical variables. A p value<0.05was considered statistical significant. Identifying risk factors with respect to early and late rehemorrhage after treatment of intracranial aneurysms, and illustrated our empirical prevention and management on rehemorrhage. ResultsEarly rehemorrhage occurred in18cases. The incidence and mortality of early rehemorrhage was1.24%(18/1455) and55.6%(10/18), respectively. Mean time to early group rehemorrhage was4.3±3,3days, respectively. Out of18patients in early group,10patients (55.6%) had an intracerebral hematoma (ICH) on initial computed tomography (CT),9(50%) had incomplete occlusion result. No further measures were taken in2patients; Cerebral angiography was given in3patients; Two patients underwent aneurysm clipping surgery; Two patients underwent bilateral lateral external drainage; One patients underwent hematoma and ventricular drainage; Six patients underwent hematoma and decompressive craniectomy; Two patients underwent craniectomy decompression and ventricular drainage. At the time of the discharge, ten patients died, another5sustained severe disabilities, and3had good recovery. Multiple univariate logistic regression analysis identified hypertension, vasospasm, initial incomplete occlusion, Hunt-Hess grade III-V, located in the AcomA, and presence of ICH on initial CT as risk factors for early rehemorrhage. Late rehemorrhage occurred in6cases. The incidence and mortality of late rehemorrhage was0.63%(6/952) and0%(0/6), respectively. Mean time to early group rehemorrhage was39.8±16.9months, respectively. All6patients in late group showed recanalization on post-rehemorrhage angiography and made an excellent recovery. According to the results of the univariate statistical analysis and the multivariate logistic regression analysis, the results showed that hypertension, initial incomplete occlusion, and aneurysmal recanalization could induce late rehemorrhage.ConclusionsRehemorrhage is the most serious complications after the endovascular treatment. In our series, we found that rehemorrhage is still a rare but significant threat after endovascular treatment of ruptured intracranial aneurysms. Hypertension, vasospasm, initial incomplete occlusion, Hunt-Hess grade III-V, located in the AcomA, and presence of ICH on initial CT seemed to be related to early rehemorrhage after coiling. Hypertension, initial incomplete occlusion, and aneurysmal recanalization could induce late rehemorrhage. Importantly, patients should be defecation and sedative treatments after embolization for the purpose of prevent intracranial rehemorrhage due to defecation difficulties and agitation with high blood pressure. Intraventricular hemorrhage and subarachnoid hemorrhage generally recommended early lumbar puncture or lumbar catheter drainage, drainage BCSF prevent vasospasm caused by cerebral ischemia,cerebral infarction and other complications. It is preferable to embolizing aneurysms completely as far as possible in the surgery, together with the timely reembolization, hematoma dissection and decompressive craniectomy after the rehemorrhage. Patients with parenchymal hemorrhage should have conservative treatment if small amount of bleeding and not brain herniation signs. If not, hematoma dissection should be done immediate to avoid rebleeding, preferably together with the aneurysm clipping. Decompressive craniectomy is recommended according to the situation.