Endovascular embolization for intracranial aneurysms has the advantages of lower death and disability rates, less trauma, and faster recovery compared with craniotomy, and has gradually become the preferred method for early treatment of intracranial aneurysms. However, serious complications such as intraoperative aneurysm rupture still occur. The incidence of intraoperative rupture of spring coil embolization aneurysm is 2.51% and the morbidity and mortality rate is 0.99% as reported by the statistics of large number of cases abroad. The incidence of aneurysm rupture during craniotomy ranges from 7 to 51%, and the general incidence is 15 to 20%. The relationship between timely detection and treatment of aneurysm rupture during embolization and the prognosis of patients is rarely reported in the domestic and international literature. From February 2008 to December 2008, 127 patients with ruptured intracranial aneurysm were treated with intravascular embolization in our department, among which 5 cases of intraoperative aneurysm rupture occurred, and the author reports the causes, treatment and results of intracranial aneurysm rupture during embolization. General information: There were 5 cases, 3 males and 2 females, aged 44y, 49y, 53y, 67y, 71y. All of them had acute rupture of aneurysm before operation, and the preoperative CT scan showed subarachnoid hemorrhage. There were four cases of subarachnoid hemorrhage (SAH) and one case of two SAHs, all of whom were conscious. Cerebral angiography was performed with Advantx-LCN + double C-arm angiography system from GE, U.S.A. The aneurysm sites shown on cerebral angiography were posterior communicating artery in 2 cases, middle cerebral artery in 1 case, and anterior communicating artery in 2 cases. Aneurysm neck >4mm in 2 cases, 4mm in 3 cases, 1/2, severe tortuosity of the internal carotid artery in 2 cases, and cerebral vasospasm in 2 cases. Endovascular treatment All patients were treated under general anesthesia with endotracheal intubation. A total cerebral angiogram was performed via right femoral artery puncture, and after finding the aneurysm, 3D rotation was performed to select the working angle and measure the size of the aneurysm. Intraoperatively, systemic heparinization was performed and nimodipine was pumped in a micro-pump. The Excel-10 microcatheter was introduced into the lateral ICA of the aneurysm-carrying artery under the guidance of a Transend-10 microguide wire, and the aneurysm was sequentially filled with an appropriate spring coil after the tip entered the aneurysm under “Roadmapping”. Each time the spring coil was removed, a radiograph was taken to confirm that the spring coil was in the aneurysm. The aneurysm rupture occurred in 5 cases during embolization: 1 case when the guidewire pierced the aneurysm during the introduction of the Excel-10 microcatheter, 1 case when the microcatheter entered the aneurysm, 1 case when the first spring coil was inserted and released, 1 case when the second spring coil was inserted, and 1 case when the last spring coil was inserted and released. The aneurysm ruptured when the contrast agent was injected through the introducer, and the contrast agent was seen to cascade into the subarachnoid space. Intraoperative management Ichthyoprotein sedation immediately neutralized heparin, controlled hypotension, close observation of patient signs such as pupillary changes, and adjustment of the microguide wire and microcatheter to continue to deliver the spring coil as planned. Postoperative CT review Intracranial aneurysm is a common vascular disease of the central nervous system, and embolization treatment by transarterial route is a minimally invasive treatment. In recent years, more and more patients choose minimally invasive endovascular embolization for intracranial aneurysms, and the incidence of intracranial aneurysm re-rupture during embolization. The incidence of re-rupture of intracranial aneurysm during embolization is 4.4% as reported by domestic Li Minghua et al. The incidence of this group is 4.17%, and the prognosis is good after proper treatment. The rupture of aneurysm during embolization can still achieve satisfactory clinical results and give satisfactory treatment to patients after proper treatment. Factors present in the re-rupture of intracranial aneurysm during embolization are: (1) blood pressure fluctuation caused by induction of anesthesia; (2) inappropriate heparinization. (3) Rupture of aneurysm due to increase in blood pressure after contrast injection. The pressure of the injected contrast agent is transmitted to a weak point in the aneurysm wall, especially during superselective imaging; (4) microcatheter penetration of the aneurysm wall. (5) Microcatheterization of the microcatheter jumps through the aneurysm wall. In the case of tortuous vessels and obvious sclerosis, the microcatheter has difficulty entering the aneurysm and is repeated several times near the mouth of the aneurysm, and the microcatheter guided by the guidewire suddenly pops into the aneurysm and punctures the aneurysm. (6) The spring coil tops the aneurysm wall, the spring coil is poorly flexible or the size of the spring coil is not selected appropriately. (7) Intraoperative aneurysm rupture is also related to the size and shape of the aneurysm. The probability of rebleeding varies significantly among different shapes of aneurysms. It is generally believed that irregularly shaped aneurysms, especially cucurbit-shaped aneurysms, are more likely to rupture than saccular aneurysms. After an aneurysm ruptures and bleeds, a localized hematoma forms, and the rupture opening of the aneurysm may be connected to the hematoma for a long time to form a pseudoaneurysm. The distal sac of a cucullar aneurysm is mostly a pseudoaneurysm, which has no vessel wall and can withstand less maximum arterial pressure than a saccular aneurysm, and thus is more likely to rupture and bleed again than a saccular aneurysm. In addition, narrow aneurysms [5] and aneurysms with very thin necks are also more prone to rupture. Aneurysms are the result of the outward expansion of the arterial wall. In the case of particularly long aneurysms and aneurysms with a particularly thin neck, the arterial wall at the top of the aneurysm is particularly dilated, and the extremely weak aneurysm wall is less able to withstand pressure and is more likely to rupture. Intraoperative rupture of aneurysm: The following signs can indicate aneurysm rupture during embolization: Firstly, spillage of the contrast medium. The contrast agent is retained in the subarachnoid space or brain parenchyma beyond the contours of the aneurysm and artery. This is the most favorable basis for aneurysm rupture. Second clinical signs of acute intracranial hypertension appear, such as elevated blood pressure, slowed heart rate, and enlarged pupils. Third microguidelines, microcatheters, and spring coils penetrate the aneurysm’s choroid or the basket-frame choroid woven by the spring coils. Fourth, the patient has a grand mal seizure during embolization, suggesting aneurysm hemorrhage. Fifth, changes in the morphology of the aneurysm and the aggregation and coiling of the spring coils that have been placed are all indicative of aneurysm rupture. Not all aneurysm ruptures are associated with spillage of contrast medium, therefore, unexplained increase in blood pressure and slow pulse rate should be highly alerted to aneurysm rupture. We use the following methods: (1) controlled hypotension and immediate neutralization of heparin. (2) Use contrast as little as possible until the aneurysm is satisfactorily occluded. Because its entry into the subarachnoid space can cause severe vasospasm. (3) If the microcatheter is in place, proceed with embolization. If the spring coil has penetrated the aneurysm, it should not be withdrawn, but a posterior portion of the spring should be attempted to be placed in the aneurysm and embolization should be continued. (4) CT examination should be performed immediately after embolization. When the microcatheter penetrates the aneurysm, choose a suitable spring coil, place a portion of the spring coil beyond the head end of the microcatheter, then retract the microcatheter into the aneurysm and continue to place the spring coil until the aneurysm lumen is completely filled. According to the report of W illinskyR et al, another treatment method for microcatheter penetration of aneurysm is to deliver the second microcatheter into the aneurysm for spring-ring embolization, while the first microcatheter is located in place, and both microcatheters can be withdrawn after the end of filling, and this method can prevent bleeding. In this group, one case of microcatheter penetration of aneurysm, one of the previous methods was used, and the effect was satisfactory. When the spring coil tops through the aneurysm, as long as the microcatheter is confirmed to be located in the aneurysm lumen, do not back off the spring coil, but continue to feed the spring coil to make it coiled in the aneurysm lumen, then uncoil it and continue to fill the spring coil until the aneurysm lumen is completely filled. In three cases of this group, the spring coil broke through the aneurysm wall, and the results of using this method were satisfactory. When the micro-guide wire penetrated the aneurysm wall, the micro-guide wire was withdrawn into the aneurysm, and the micro-catheter continued to be sent into the aneurysm, and the spring coil was used to fill the aneurysm lumen until it was completely occluded. A total of 1 case of microguide wire penetrating the aneurysm in this group had good results using this method. In this group, there were 5 cases with clear causes, which were puncture of the aneurysm by the microguide wire and catheter, and jacking of the aneurysm when placing the first, second and last spring coils. At this point, it is not necessary to perform imaging, but to take prompt measures to continue delivering the spring coil to achieve hemostasis and then continue dense filling. Embolization of the aneurysm is performed as soon as possible, and bleeding can be controlled only after complete embolization of the aneurysm. Prevention of intraoperative rupture of aneurysm: During endovascular intervention for intracranial aneurysm, careful consideration of each step of the operation will help to reduce the occurrence of intraoperative accidents, even including careful reading of the film before the operation will improve the chance of successful intraoperative operation. General anesthesia allows the patient to remain quiet, reduce agitation, and maintain the same position, and is performed by an experienced anesthesiologist to avoid excessive changes in blood pressure during induction of anesthesia, which is first controlled between 13.33/8 kPa before induction [11]. Embolization was performed by a skilled and experienced physician. A high-performance three-dimensional digital subtraction angiography machine is used, which facilitates the physician to observe more clearly the location, size, neck of the aneurysm and the relationship with the aneurysm-carrying artery to improve the accuracy and safety of treatment; reasonable heparinization and close monitoring under the guidance of the road map are performed as carefully and accurately as possible; the shaping of the anterior end of the microcatheter must be suitable for the relationship between the aneurysm and the aneurysm-carrying artery to improve its stability. Double-bending plasticity of the head end of the microcatheter before embolization according to the location, morphology, size of the aneurysm and the relationship of the aneurysm-carrying artery can keep the microcatheter stable during the delivery of the spring coil. The operation of the microcatheter should be advanced slowly under the path diagram, and the vessels are too tortuous, and the accumulated tension in the catheter pushing is suddenly released and punctures the aneurysm. Jumping forward of the microcatheter should be avoided as much as possible. The advance of the microcatheter can be controlled as follows: Place the guiding catheter as high as possible to minimize bending. Or place the microguide wire over the aneurysm and then the microcatheter also over the aneurysm, and then retract the microcatheter into the aneurysm. As the microcatheter approaches the aneurysm, the microguide wire must not protrude too far from the microcatheter. During the process of microcatheter entry into the aneurysm, retreat the microguide wire while entering the microcatheter, and retreat the microguide wire into the microcatheter when the microcatheter enters the aneurysm to avoid the microguide wire damaging the aneurysm wall. The microcatheter should not be placed directly against the aneurysm wall to prevent the spring coil from being pushed out and not being able to coil and pierce the aneurysm. Adjust the position of the head end of the microcatheter after it enters the aneurysm lumen. The head end should not be placed against the aneurysm wall to avoid puncturing the aneurysm when the microguiding wire is withdrawn. In the absence of certainty, transcatheter aneurysm angiography is not recommended in principle after the microcatheter reaches the aneurysm lumen. In patients with acute ruptured aneurysms, transcatheter angiography should not be performed at too high a pressure when injecting contrast because of the high position of its guiding catheter. This is especially true when doing a hand-pushed contrast in the pathogram to avoid rupture of the aneurysm due to contrast injection. Some aneurysms are difficult to introduce the microcatheter into the aneurysm lumen along the microguide wire because of the small angle and many turns of the aneurysm-carrying artery. It is recommended that the head end of the microcatheter be shaped so that it is in the shape of a small spring coil, so that it can be naturally coiled when it enters the aneurysm cavity and does not push against the aneurysm wall and cause the possibility of breaking the aneurysm wall. Tension should be reduced after the microcatheter is in place so as not to cause the microcatheter to move forward after the microguide retreats or during placement of the spring coil. In cases where the aneurysm is located at a site that requires several bends, especially sharp bends, to reach the catheter, stiffer guidewires are often selected to enhance the catheter pushing force and assist in catheter placement. However, stiffer guidewires are less compliant, and twisting of the guidewire may result in a sudden rotation of the guidewire several turns with sudden advancement or retraction of the tip of the guidewire. The sudden advancement of the guidewire may puncture the aneurysm wall, and if the tip of the guidewire is located just inside the small sac or at the sharp corner of an irregular aneurysm, aneurysm rupture is highly likely. The accompanying rotation may tear a large fissure in the aneurysm wall. When a softer guidewire is used with a stiffer catheter, the catheter may become embedded in the neck of the aneurysm, and increased thrust may also cause the catheter to bounce forward. When the spring coil is just pushed out of the catheter before it is coiled into a loop, if it is obstructed by the aneurysm wall, the tremendous pressure generated by the head end of the coil against the aneurysm wall can puncture the aneurysm wall and rupture the aneurysm. For irregular-shaped aneurysms, i.e., aneurysms with “vesicles”, it is appropriate to choose soft spring coils for embolization. The diameter of the first spring coil should be larger than the aneurysm neck and equal to the aneurysm body, and as long as possible, so that it can be coiled into a basket shape in the aneurysm cavity. The diameter and volume of the aneurysm must be precisely calculated when filling the residual neck of the aneurysm to avoid tearing the neck of the aneurysm by oversizing the spring coil or overfilling it. The guidewire is withdrawn after imaging before the spring coil is released to ensure that the spring coil has been released.