Objective To summarize the effects of treatment strategy, surgical access and intraoperative situation management on the outcome of microsurgical treatment of intracranial aneurysms. Methods From July 1996 to June 2004, 47 patients with intracranial aneurysms were treated with microsurgery using different surgical accesses and aneurysm treatments. Results There were 38 cases with good postoperative recovery, 3 cases of death, 2 cases of hemiplegia, 1 case of monocular blindness, 1 case of motor nerve palsy, 1 case of aneurysm re-rupture, and 1 case of aneurysm wrapping without symptomatic improvement. Conclusion Adoption of reasonable surgical treatment strategy and surgical access, correct handling of various situations during the operation and meticulous examination after aneurysm clipping are the basic guarantee to ensure that microsurgical treatment of aneurysm achieves good therapeutic effect. Up to now, microsurgery is still the most reliable treatment for intracranial aneurysm clipping. From March 1996 to June 2004, a total of 52 cases of intracranial aneurysms were admitted to our department, of which 47 cases underwent craniotomy microsurgery, including 43 cases of aneurysm clipping, 2 cases of aneurysm wrapping, and 2 cases of aneurysm-carrying arterial clipping, with craniotomy accounting for 90% of the total number of cases. After the operation, the patients recovered well in 38 cases, died in 3 cases, hemiplegia in 2 cases, monocular blindness in 1 case, motor nerve paralysis in 1 case, aneurysm re-rupture in 1 case, and no improvement of symptoms after aneurysm wrapping in 1 case. 1, Objects and Methods 1.1, General Information There were 47 cases in this group, 29 male and 18 female, aged 21-65 years old, with an average age of 53.3 years old. 1.2, Symptoms and signs 46 patients started with subarachnoid hemorrhage, 2 of which were the second hemorrhage. 1 patient was consulted for headache and dizziness for 3 months, and high density shadow in the saddle region was found on cranial CT. One patient had persistent coma after the onset of the disease, and 14 patients had transient impairment of consciousness. All patients with subarachnoid hemorrhage had headache, neck pain, and cervical ankylosis of varying degrees, and 22 patients had motor nerve palsy on one side. According to the Hunt-Hess classification, 44 cases were graded I-II, and 1 case was graded IV. 1.3 Imaging examination: All 46 patients with subarachnoid hemorrhage were examined by cranial CT within 24 hours after the onset of the disease, and all of them were found to have different degrees of blood accumulation in the cerebral pools, among which 8 cases were combined with intraventricular hemorrhage and 6 cases were combined with intracerebral hematomas; 1 case with no history of subarachnoid hemorrhage, who had consulted the doctor for 3 months because of headache and dizziness, was found to have high-density punctate calcified shadows in the saddle area by cranial CT. All patients underwent femoral artery cannulation, digital subtraction, and whole brain angiography. There were 23 cases of one-sided internal carotid artery-posterior communicating artery aneurysm, 1 case of bilateral internal carotid artery-posterior communicating artery aneurysm, 6 cases of internal carotid artery terminal aneurysm, 1 case of ophthalmic artery aneurysm, 5 cases of anterior communicating artery aneurysm, 4 cases of anterior cerebral artery aneurysm (1 case of segment A1 aneurysm and 3 cases of pericallosal aneurysm), 4 cases of middle cerebral artery bifurcation aneurysm, and 2 cases of posterior cerebral artery segment P2 aneurysm. 1.4 Timing of angiography and surgical treatment 31 cases were admitted to the hospital within 24 hours of the onset of the disease, of which 1 case was angiographed and operated on within 24 hours and 3 cases were angiographed and operated on within 72 hours. There were 27 cases of angiography and surgery within one week. The remaining patients underwent imaging and surgery within 7-14 days of onset. 1.5 Surgical access All posterior communicating artery aneurysms, internal carotid artery aneurysms, middle cerebral artery aneurysms, ophthalmic artery aneurysms, and one anterior communicating artery aneurysm were operated by the wing-point approach; eight anterior communicating artery aneurysms and anterior cerebral artery aneurysms were treated by frontal craniotomy and mediastinal fissure approach; and two cases of posterior cerebral artery aneurysms of the P2 segment were treated by temporal base approach. 1.6 Treatment of aneurysms 37 cases of aneurysms were successfully clamped, 8 cases of aneurysms ruptured during exposure and separation, of which 6 cases of aneurysms were finally clamped, 1 case was wrapped, and 1 case of aneurysm-carrying artery was clamped; the aneurysm couldn’t be safely clamped, and only 1 case of wrapping and 1 case of simple aneurysm-carrying artery was clamped. 2. Results Among the 47 cases of aneurysm surgery in the whole group, there were 38 cases with good postoperative recovery, 3 cases of death, 2 cases of hemiplegia, 1 case of monocular blindness, 1 case of motor nerve paralysis, 1 case of re-rupture of aneurysm, and 1 case of no improvement of symptoms after aneurysm parcel surgery. There were 37 cases of successful closure of aneurysm during operation, and 35 cases had good postoperative recovery. 1 case of giant internal carotid artery terminal aneurysm was safely closed during operation, but due to the fear of insufficient force of aneurysm clamp, the aneurysm was wrapped with muscle and EC cerumen, and more than two months after operation, the patient experienced gradual loss of vision on the same side, and eventually became blind in one eye. On follow-up angiography 3 months after surgery, the aneurysm disappeared, the internal carotid artery system was smooth, and the ipsilateral ophthalmic artery was visualized; 1 case of Hunt-Hess IV grade, aneurysm of the A1 segment of the anterior cerebral artery was successfully clipped in emergency surgery, but there was obvious cerebral swelling during the operation and the intracranial pressure was increased, and severe arterial spasms and cerebral infarctions occurred, resulting in hemiplegia, even after decompression by the debridement flap and postoperative treatments; 1 case of arachnoiditis of the same part of the brain occurred again in the 9th day after the operation. On the 9th postoperative day, a subarachnoid hemorrhage from the same site occurred again, and the presence of incomplete aneurysm clamping was considered, but the family refused to operate again and was automatically discharged from the hospital. There were 6 cases of aneurysm rupture during exposure or separation of aneurysm, but the aneurysm was finally clamped, of which 2 cases suffered from cerebral ischemia and swelling, brain swelling, and the other case suffered from respiratory and cardiac arrest, and all 3 cases died of brainstem failure within 10 days after surgery, and the remaining 3 cases recovered well after postoperative treatment. One case of aneurysm wall wrapping and reinforcement due to intraoperative aneurysm rupture was a patient with posterior cerebral artery aneurysm, who suffered from ipsilateral motor nerve paralysis after the operation. Another case of middle cerebral artery aneurysm was forced to undergo middle cerebral artery trunk clamping due to the replacement of aneurysm clamps, which resulted in the complete dissections of the aneurysm, and the contralateral side of the limbs were left incompletely paralyzed after the operation. In 1 case of anterior communicating artery aneurysm, the wall of the aneurysm was completely calcified, and the clamping of the neck of the aneurysm led to obvious shortening, narrowing and deformation of the anterior communicating artery, forcing it to be wrapped with muscle plus EC ear cerebrospinal gel, and there was still a headache after the operation. 1 case of pericallosal aneurysm was only carried out by aneurysm-carrying artery clamping (early stage case). 3, Discussion 3.1, preoperative determination of the number, location, morphology and pointing of aneurysms For patients with aneurysms combined with subarachnoid hemorrhage, we should be alert to the possibility of multiple intracranial aneurysms, which has been reported in the literature to be as high as 33% [1, 2, 14]. Therefore, preoperative cerebral angiography should include at least bilateral internal carotid arteries and one side of the vertebral artery system, and it is best to complete the standard “four-artery angiography (bilateral carotid arteries, bilateral vertebral arteries)”, so as to avoid the omission of aneurysms, especially the presence of unbleeding aneurysms. In our case, a patient with subarachnoid hemorrhage was found to have an aneurysm of the right internal carotid artery and posterior communicating artery on the first imaging, which was not performed because of the difficulty of cannulation of the left internal carotid artery. One year after aneurysm clipping at our hospital, a left-sided predominant subarachnoid hemorrhage occurred, and the presence of a left internal carotid artery-posterior communicating artery aneurysm was confirmed by re-imaging, and the aneurysm ruptured early during the operation, resulting in clinical death, which should be taken as a warning. Aneurysm site and morphology directly determines the choice of treatment [3, 4, 5], with the three cases of internal carotid artery cavernous sinus segment giant aneurysm admitted at the same time in this group, two cases of endovascular intervention, balloon occlusion of the tumor-carrying arteries, one case of Silver-Stone clip slowly clamped off the same side of the internal carotid artery, have received a good effect; one case of bilateral internal carotid artery giant serpentine aneurysm, a case of basilar artery Giant aneurysms are only treated conservatively due to the limitation of conditions. For an aneurysm that is decided to be operated, the choice of surgical access and aneurysm clips should be decided according to its size, morphology, and relationship with the aneurysm-carrying artery. For aneurysms that are acutely angular and have a small caruncle on contrast, it is predicted that the wall of the aneurysm is weak at the site and is prone to intraoperative rupture, and adequate preoperative preparations should be made. The preoperative determination of aneurysm pointing should follow the method of Yasargil [2], in which the aneurysm pointing is altered by a 90-degree rotation in the median sagittal plane with respect to the standard lateral angiogram when the patient is in the supine position intraoperatively. Knowledge and mastery of this principle can be of great help in quickly determining the specific site of the aneurysm and the anatomical relationship of the ratio intraoperatively. 3.2, the choice of surgical access In this group of cases, all internal carotid artery – posterior communicating artery aneurysms, internal carotid artery terminal aneurysms, middle cerebral artery aneurysms, ophthalmic artery aneurysms and one anterior communicating artery aneurysm were used in the pterygoid point approach. The range of skin incision and bone flap can be appropriately extended to the frontal or temporal region according to the site of the aneurysm and pointing, as well as the site of the intracranial hematoma, and a satisfactory exposure requirement can be obtained [6, 7]. For anterior traffic aneurysms then the pointing of the aneurysm influences the choice of surgical access to a greater extent [8, 9. 10, 11]. If the aneurysm points anteriorly or inferiorly (optic nerve and optic crossings), the aneurysm body usually has no serious adhesion to the frontal lobe surface, but is closely related to the optic nerve, optic crossings and optic bundles; the A1 segment of the bilateral anterior cerebral arteries can be well exposed from the anterior-lateral direction, and at the same time the anterior communicating artery perforating branch is located on the opposite side of the aneurysm, in which case both the wing-point and mediastinal fissure approaches can be used to obtain a satisfactory and safe disclosure. If the aneurysm is pointing upward (located in the longitudinal fissure, between the A2 segments of the anterior cerebral arteries on both sides) or posteriorly (pointing to the intercerebral peduncle fossa), the aneurysm is adherent to the frontal lobe base or even buried in the frontal lobe straight gyrus or longitudinal fissure, and the contralateral anterior cerebral arteries are obscured laterally by A1 segments of the anterior cerebral arteries. Early rupture of the aneurysm can be avoided by lifting the frontal lobe, and at the same time, the anterior communicating artery and the A1 and A2 segments of the anterior cerebral arteries can be satisfactorily exposed when the neck of the aneurysm is revealed, which is convenient for further separation and control. Anterior communicating artery segment A2 and pericallosal artery aneurysms are routinely operated by transmedial approach. Posterior cerebral artery P2 segment aneurysm is operated by infratemporal approach, which is more adequate for intraoperative visualization. However, for the left P2 segment aneurysm, preoperative imaging should be used to assess the location and course of Labbe’s vein adequately, so as to avoid forced dissection resulting in the occurrence of postoperative aphasia. If it is impossible to preserve the left Labbe vein in the preoperative assessment, or for huge aneurysms pointing to the temporal side, it is more reasonable to choose the wing point approach or frontotemporal orbital zygomatic approach, which can avoid the damage of the Labbe vein, and expose the proximal part of the aneurysmal artery in advance, which is convenient for intraoperative control [12, 13]. 3.3 Treatment of intraoperative rupture of aneurysm Intraoperative rupture of aneurysm is related to the timing of surgery, the characteristics of the aneurysm itself, the technique of isolation and the experience of the operator, and can be divided into two cases: early rupture and rupture during the dissection of the aneurysm. In this group, there were 8 cases of intraoperative rupture of aneurysm, 2 cases of early rupture of aneurysm, i.e., rupture of aneurysm before and after incision of dura mater; 5 cases of rupture during dissection of neck of aneurysm, and 1 case of rupture during adjustment of aneurysm clamp. In the case of intraoperative aneurysm rupture, the calmness and correct command of the operator and the effective cooperation of the entire surgical team are crucial. In this group, three cases of intraoperative aneurysm rupture failed to expose the aneurysm in a timely and rapid manner at the initial stage, resulting in excessive blood loss and severe cerebral swelling. Although the aneurysm was finally clamped and internal and external decompression and postoperative treatments were performed, the patients were all in deep coma after the operation, and they died immediately after the operation. In another case, the aneurysm neck was torn when replacing the aneurysm clip, which ultimately led to the dissection of the aneurysm from the bifurcation of the middle cerebral artery and failed to anastomose the severed end of the artery, and the contralateral limb paralysis due to the middle cerebral artery infarction appeared in the postoperative period. The patient had no serious postoperative complications. At the same time, it should be emphasized that 2-3 suitable temporary blocking clips are as important and essential for any case of aneurysm surgery as suitable permanent blocking clips. 3.4. Management of giant aneurysms Surgery for giant aneurysms is more complicated. In this group, there was only one case of giant aneurysm of the terminal segment of internal carotid artery, in which there was still arterial hemorrhage after the puncture of the aneurysm capsule due to insufficient force of the aneurysm clamp during the operation, forcing to perform aneurysm capsule wrapping, but there was a gradual decrease of vision in the ipsilateral eye in the first two months after the operation, and finally, there was blindness. After 3 months of postoperative follow-up imaging, the aneurysm disappeared, the internal carotid artery system was patent, and the ipsilateral ophthalmic artery was visualized. It was considered that the blindness was related to the compression of the ipsilateral optic nerve by the huge aneurysm and the extremely outer wall wrapping material. If the aneurysm can be clamped or ligated and resected intraoperatively, the above complications can be avoided [14, 15]. 3.5. Examination after aneurysm clamping Completion of aneurysm neck clamping does not mean that the surgical operation of the aneurysm is successfully completed, and the following operations should be carefully completed: ① Expose the aneurysm and peri-aneurysm structure as completely as possible under the microscope, and observe whether the neck of the aneurysm is completely clamped in all directions, and whether the wall of the aneurysm-carrying artery, its branches, or cranial nerves have been clamped together, and whether there is any aneurysm residue between the aneurysm-carrying artery and the aneurysm clamp. Whether the aneurysm-carrying artery and its adjacent branches are twisted or occluded due to the placement of aneurysm clips, and whether the aneurysm-carrying artery and its adjacent branches are twisted or occluded due to the placement of aneurysm clips. In recent years, it has become more convenient to use brain endoscopy to perform these operations [16]. In this group, one case of anterior communicating artery aneurysm clipping surgery on the 9th day after the same site again appeared subarachnoid hemorrhage, considering the existence of aneurysm clipping incomplete, residual aneurysm re-rupture, because the patient’s family refused to reopen the surgery and could not be confirmed; another case of anterior communicating artery aneurysm wall is completely calcified, the neck of the aneurysm that led to the closure of the anterior communicating artery is obviously shortened, stenosis and deformation, forced to switch to the muscle plus EC ear cerebral gel wrapped aneurysm; ② fine needle Fine needle puncture and aspiration of blood inside the aneurysm to observe the filling of the aneurysm, such as refilling, it indicates that the neck of the aneurysm is incompletely clamped or the aneurysm has other vascular traffic, the former should be replaced, increased or strengthened clamps, and the latter should be based on the nature of the artery into the wall of the aneurysm treatment, the vagus artery can be dissected, and the normal perforating branch is considered to be aneurysm molding treatment or an arterial graft anastomosis, but the latter step is more difficult to operate [17]; ③. Whether there is occlusion or spasm of the aneurysm-carrying artery can be preliminarily determined according to the change of arterial caliber, but a more accurate assessment depends on ultrasound multispectral detection; ④ Further remove the cerebral pool, the subarachnoid space, and the intracerebral accumulation of blood in the brain adjacent to the aneurysm, and flush with poppy alkaline saline, to prevent the occurrence of postoperative arterial spasm and hydrocephalus, and place a cerebral pool drainage tube if necessary; ⑤ Remove the cerebral compression plate, and reposition the brain tissues that are pulled apart during the operation, and reconfirm the aneurysm clamping and the aneurysm graft. (5) Remove the cerebral pressure plate, reposition the brain tissue that was pulled apart during the operation, and reconfirm that the aneurysm clip has not been displaced or twisted and the aneurysm-carrying artery has not been deformed or stenosed after the brain tissue is repositioned. Patiently completing the above operations can maximize the success of the operation and minimize postoperative complications. Reasonable therapeutic strategy and surgical access, correct handling of various situations during the operation and careful examination after aneurysm clipping are the basic guarantee for good efficacy of microsurgical treatment of aneurysms.