Embolization of cerebral aneurysms has been unanimously recognized as superior to surgical intervention because of its minimally invasive nature and equivalence to surgical clamping, especially in the early treatment of ruptured aneurysms and in the treatment of posterior circulation aneurysms. Many neurosurgical centers around the world have standardized intervention as the treatment of choice for cerebral aneurysms. However, we should not ignore the complications associated with the operation due to its minimally invasive nature; on the contrary, we should pay great attention to the non-directive nature of interventional procedures and the suddenness of complications, and actively make preparations to cope with and prevent possible complications. This article retrospectively analyzes the occurrence of complications during electrolytic platinum ring embolization in 108 patients with cerebral aneurysms, and discusses the causes, preventive and therapeutic measures in the light of the literature. From February 1992 to December 2007, there were 108 cases (112) of cerebral aneurysms treated with electro-detachable platinum coils (EDPC) embolization, of which 106 cases were subarachnoid hemorrhage (SAH) cases. The preoperative Hunt & Hess grading was 0 in 2 cases, I in 55 cases, II-III in 36 cases, and IV-V in 15 cases.The EDPCs were made by Target Corporation, a subsidiary of Boston-Science International, Inc. in the United States, and EDCs made by Dendron Corporation in Germany. Complications occurred in 11 cases (11 aneurysms): including intraoperative rupture of the aneurysm, thrombosis of the aneurysm-carrying artery or cerebral arterial embolism, herniation of the electrolytic platinum ring resulting in occlusion of the aneurysm-carrying artery or escape from the aneurysm, and failure of the platinum ring to be dislodged, unspiralized, or retained in the body. Results Complications occurred in 11 of 108 cases (10.2%). Among them, there were 3 cases of ruptured aneurysm bleeding, 2 cases of intraoperative vasospasm and thrombosis, and 1 case of thromboembolism. The platinum ring herniated into the aneurysm-carrying artery in 3 cases and dislodged from the aneurysm in 1 case. There was 1 case of platinum ring not dislodged, and 1 case of platinum ring dislodged from the spiral and retained in the body; 9 cases of 106 cases of SAH in this group were combined with hydrocephalus, and all of them were firstly embolized and then shunted, and all of them showed significant improvement of hydrocephalus after shunt operation. Aneurysm rupture and hemorrhage occurred in 3 patients during embolization, and 2 patients were continued embolization by EDPC to stop bleeding. After a follow-up of 6 to 24 months, CT showed absorption of the original hemorrhage without rebleeding. 1 case was referred to surgical emergency surgery because general anesthesia was not administered preoperatively. One patient with platinum coil unspiralized and retained in vivo had no clinical symptoms with long-term warfarin anticoagulation. The three patients who had embolic events were treated with antispasmodic, thrombolytic and symptomatic treatments, and no neurological deficits remained after the operation. Herniation of the platinum ring into the aneurysm-carrying artery occurred in 3 cases: all of them were posterior traffic wide carotid artery aneurysms (2 right, 1 left), and all of them resulted in occlusion of the ipsilateral internal carotid artery after herniation. 1 patient had no clinical symptoms due to good collateral circulation, 1 had left hemiplegia, and the other 1 had right hemiplegia with aphasia. Therefore, there were 2 cases (2%) of permanent neurologic dysfunction and 4 cases (4%) of transient neurologic dysfunction due to the above complications. There were no fatal cases in this group. Discussion 1, intraoperative aneurysm rupture Rupture and bleeding occurred during aneurysm embolization, the reasons may be: repeated rupture and bleeding of the aneurysm to form an incomplete pseudoaneurysm, the aneurysm wall is incomplete, rupture on its own in the fluctuation of blood pressure or arteriography; microcatheter and spring coil placed in the process of damage to the aneurysm or through the aneurysm. In this group, three cases of intraoperative rupture of aneurysm occurred when the first spring coil was placed. In one case, due to the small amount of bleeding, the patient had a transient aggravation of headache in the postoperative period, and no special treatment was made. In the other two cases, the bleeding was large and the patients underwent immediate emergency craniotomy. The operator’s experience is that according to the location of the aneurysm, choosing the appropriate shape, size and softness of the spring coil is an important preventive measure. And once an aneurysm rupture occurs intraoperatively, the operator should maintain sedation and rapidly neutralize heparin while lowering blood pressure. If the spring coil crosses the aneurysm and is placed externally, do not pull back, try to place the posterior portion of the spring coil inside the aneurysm sac, and then continue to do intratumoral aneurysm embolization to reduce bleeding, and minimize contrast injection during embolization. Postoperatively, according to the clinical manifestations and CT examination results, the degree of hemorrhage can be understood, and a small amount of hemorrhage can be replaced by lumbar puncture of cerebrospinal fluid. If the microcatheter intubation is not yet in place, or embolization is difficult or rupture is large and bleeding is more of these three cases, immediate surgery should be de-bone flap decompression, removal of intracranial hematoma. 2.Vasospasm and thrombosis Vasospasm and thrombosis are the most important disabling and fatal factors for patients with ruptured and bleeding aneurysm.During the process of GDC electrolysis, it is easy to adsorb erythrocytes and platelets to aggregate into thrombus, and also due to the protruding of spring coils into the aneurysmal arteries leading to thrombosis, which can result in cerebral embolism and cerebral infarction once the blood clots are dislodged. Therefore, heparinization is crucial in embolization, and some scholars have reported that as long as no bleeding occurs within 2h, regular systemic heparinization should be given intraoperatively. The occurrence of vasospasm is important to prevent, early use of calcium channel blockers can reduce the incidence of vasospasm, but for the occurrence of vasospasm Nimoton therapy is generally difficult to be effective. In this group of cases, micropump injection of Nimotone was used before, during and after surgery. Nonetheless, spasm and thromboembolic events occurred intraoperatively in three patients in this group, and 150 mg/500 ml of poppy saline was immediately given to dilate the blood vessels, while 50,000~100,000 u/dose of urokinase was given for thrombolysis. After active treatment, the symptoms were relieved and the thrombus was dissolved after 20-40 minutes, and it was possible to continue to complete the aneurysm embolization treatment, and no sequelae occurred in all three patients. Spring coil partially dislodged The tail end of the spring coil was dislodged to the aneurysm-carrying artery in most of the cases of wide-necked aneurysm embolization, and wide-necked aneurysm can be embolized by aneurysm neck molding technique. In addition, breakage of the spring coil push guide wire and inappropriate selection of the spring coil are also possible causes of dislodgement. Therefore, the operation technique is very important to minimize this complication, the last spring coil should not be too long, and the demand for excessively dense embolization is often one of the factors contributing to this complication. In this group, a case of right internal carotid – posterior communicating artery aneurysm 1 spring coil was dislodged from the aneurysm-carrying artery through the wide neck, and blocked to the distal angular gyrus artery with the blood flow, and a transient epilepsy had occurred in the process of spring coil dislodgement and migration, but it did not cause any symptom or dysfunction after the operation. Excessive embolization refers to the embolization of the aneurysm of the spring coil part of the convex into the aneurysm-carrying artery, resulting in the latter’s stenosis or occlusion, rather than referring to the individual part of the spring coil or the end of the head and tail end of the dislodgement of the aneurysm-carrying artery, symptomatic excessive embolization is common in the wide-necked or relatively wide-necked aneurysm,. In two cases in our group, the blood flow became significantly less and slower due to incomplete occlusion of the internal carotid artery, and the patients suffered from aphasia and hemiparesis due to cerebral infarction. The other case was spared from good compensation of collateral circulation in the anterior and posterior cerebral transportation arteries, with no dysfunction or sequelae. Because regrowth may occur after aneurysm embolization, it is generally accepted that dense embolization of aneurysms should be achieved as much as possible. It is important to embolize the aneurysm as densely as possible, but at the same time, it is important to guard against over-embolization. The correct preventive measures are: ① before embolization, we should pay attention to the observation of the aneurysm / aneurysm-carrying artery and anterior and posterior transport arteries of the compensation; ② each time before the release of imaging, observation of the aneurysm of the embolism and the aneurysm-carrying artery of the circulatory situation; ③ for the wide-necked or relatively wide-necked aneurysm should be used for aneurysm remodeling techniques. 5, the platinum ring does not unravel, unspiral and retained in vivo This group occurs platinum ring does not unravel, unspiral and retained in vivo in 1 case, these two cases are rare. The former is a serious product quality problem, which has not been reported in the literature. The latter complication has been rare since the introduction of anti-decompression spring coils. Platinum coils do not uncoil this complication is more difficult, especially after the second spring coil, because the spring coil can be retracted with the aneurysm already in the spring coil or its own twisted kink, so that the pullback, retraction can not be; pull back can also cause the proximal end of the spring coil deconvoluted, so that the re-push into the spring coil difficulties or can not be. Or, when pulling back a spring coil to adjust its position or to replace it with a suitable one, the existing spring coil is taken out. It is important to realize that although electrolytically controllable coils can be freely pushed and pulled and moderately repositioned, this is often seen with the first coil, and subsequent coils should be pulled back and repositioned with great care, stabilizing the coil before electrolysis. In the event that the spring coil becomes dislodged from the aneurysm, an attempt should be made to remove it. If it cannot be removed, the aneurysm-carrying artery should be kept open as much as possible, and thrombolysis and anticoagulation should be carried out at the same time. Postoperative anticoagulation was continued for 6 months.