Morphological Features Study And Treatment Experience Of 45 Cases Of Peripheral Intracranial Aneurysms

Purpose: To study the morphological characteristics of peripheral intracranial aneurysms,aiming to find their morphological risk factors associated with rupturing,thus providing much-needed reference for the treatment of unruptured distal aneurysms.And to study the safety and effectiveness of surgical treatment for peripheral aneurysms meanwhile.Method: The clinical data of 45 patients with peripheral aneurysms in our department of neurosurgery from October 2015 to January 2018 were retrospectively analyzed.Divided into ruptured group(n=29)and unruptured group(n=16)whether the distal aneurysms were ruptured or not.And according to the different treatments,all patients were divided into conservative treatment(n = 1),craniotomy group(n = 10)and interventional group(n = 34).3D-DSA was used to measure the neck width,diameter,length and height of the distal aneurysms and to obtain the parent artery diamete,the ansus(with or without,numbers,and position)were observed at the same time.After then calculating the aspect ration(AR),the size ration(SR)and the body neck ratio.The procedures about distal aneurysms included 8 were simple performed by clipping,1 was resected,1 was trapped with arteries bypass,coil embolization was performed in 28 patients(23 were completely embolized and 5 were subtotal embolized)and 16 were assisted by stent,the distal aneurysms or parent arteries were occluded in 6 patients.Statistical analysis after sorting out clinical data such as the general data of the patients,the main morphological parameters of the distal aneurysms and the postoperative complications and so on.Results: There was no significant difference(P > 0.05)in general data no matter studied the morphological features or analyzed the operation effect of the distal aneurysms.There were 24 cases accompanied by ansus formation in all patients,the incidence of ansus formation in ruptured group which was 65.52% was higher then that in unruptured group which was 31.25%,with significant difference(P < 0.05).There was a significant difference(P < 0.05)in AR,SR and body neck ratio between the distal aneurysms ruptured group and unruptured group,or between the distal aneurysms ruptured group and the aneurysms unruptured group.The average neck width of distal aneurysms was(2.52±1.44)mm in the rupture group,and that in the unruptured group was(3.89±1.48)mm,with a significant difference(P < 0.05)among them.In addition,we found the average neck width and diameter of distal aneurysms in distal aneurysms unruptured but other aneurysms ruptured group respectively were(2.33±0.42)mm,(2.66±0.80)mm,and they were(3.89±1.48)mm,(4.14±1.47)mm in the aneurysms unruptured group,there was a significant difference(P < 0.05);The average length,height,AR,SR,and the body neck ratio of the distal aneurysms in the distal aneurysms ruptured group were all greater than that in distal aneurysms unruptured but other aneurysms ruptured group(P < 0.05).There were 8 cases with distal aneurysms located in anterior circulation in craniotomy group,and 21 patients with peripheral aneurysms located in posterior circulation among the interventional group,with significant difference(P < 0.05)between them.The success rate of operation was 100%,no aneurysms ruptured and thrombus formation event occurred during the operation.3 patients died(all in interventional group)and 8 patients developed complications after surgery.About complications,2 in craniotomy group(including 1 cases of epilepsy,1 visual field defect)and 6 in interventional group(including 1 cases of ball paralysis,1 tinnitus,1 stent related complication,1 systemic severe complication,2 rebleed).The average follow-up period was 10.3 months(ranged 1-30 months).All the cases had on recurrence except 2 patients in interventional group.Conclusions: The formation of subtumor,the neck width,the AR,the SR and the body neck ration of aneurysms are related to the rupture of the distal aneurysms,which are the main morphological risk factors for its rupture.Rupture and hemorrhage itself can cause the morphological changes in the distal aneurysms.It is suggested that patients with unruptured intracranial distal aneurysms should be treated actively,especially who with the formation of ascus,higher AR or SR.Surgical treatment is safe and effective.The craniotomy is suitable for the anterior circulation distal aneurysms,and the posterior circulation distal aneurysms are mainly treated by endovascular treatment.