Risk factors of unruptured intracranial aneurysms instability in the elderly.

BACKGROUND: Presently, a consistent strategy for determining the stability of unruptured intracranial aneurysms (UIAs) in elderly patients is lacking, primarily due to the unique characteristics of this demographic. Our objective was to assess the risk factors contributing to aneurysm instability (growth or rupture) within the elderly population. METHODS: In this study, we compiled data from follow-up patients with UIAs spanning from November 2016 to August 2021. We specifically focused on patients aged ≥ 60 years. Clinical histories were gathered, and morphological parameters of aneurysms were measured. The growth of aneurysms was determined using the computer-assisted semi-automated measurement (CASAM). Growth and rupture rates of UIAs were calculated, and both univariate and multivariate Cox regression analyses were conducted. Additionally, Kaplan-Meier survival curves were plotted. RESULTS: A total of 184 patients with 210 aneurysms were enrolled in the study. The follow-up period encompasses 506.6 aneurysm-years and 401.4 patient-years. Among all the aneurysms, 23 aneurysms exhibited growth, with an annual aneurysm growth rate of 11.0%, and 1 (4.5%) experienced rupture, resulting in an annual aneurysm rupture rate of 0.21%. Multivariate Cox analysis identified poorly controlled hypertension (P = 0.011) and high-risk aneurysms (including anterior cerebral artery (ACA), anterior communicating artery (AcoA), posterior communicating artery aneurysm (PcoA), posterior circulation (PC) > 4 mm or distal internal carotid artery (ICAd), middle cerebral artery (MCA), and PC > 7 mm) (P = 0.006) as independent risk factors for the development of unstable aneurysms. CONCLUSIONS: In the elderly, poorly controlled hypertension and high-risk aneurysms emerge as significant risk factors for aneurysm instability. This underscores the importance of rigorous surveillance or timely intervention in patients presenting with these risk factors.

Advantages of 3D registration technology (3DRT) in clinical application of unruptured intracranial aneurysm follow-up: A novel method to judge aneurysm growth.

BACKGROUND AND PURPOSE: Currently available methods for determining aneurysm growth are not accurate enough. Therefore, we introduced a more intuitive and accurate 3D registration technology (3DRT) to judge the growth of aneurysms. MATERIALS AND METHODS: We developed an in-house technique for 3DRT and calculated its derivative parameters, voxel change rate (VCR), maximum growth vector (MGV), and parent artery coincidence (PAC). To verify the accuracy, growing aneurysms and stable aneurysms matching 1:3 were selected, and a 3DRT measurement was performed. We calculated the sensitivity, specificity, and accuracy of cases with VCR > 20%, MGV > 1 mm, and combined indicator of VCR > 20% + MGV >1 mm. In addition, we analyzed the cause of the poor registration effect, where the registration effect of PAC > 0.7 was considered acceptable. We also collected 24 consecutive aneurysms for agreement analysis of 2D manual measurement and 3DRT. RESULTS: Twenty-seven growing aneurysms and 81 stable aneurysms were included in the normal model group, and 88 aneurysms with good registration effect in the adjusted model group. For aneurysms with VCR > 20%, the sensitivity and the specificity were the highest at 81.48% and 91.35%, respectively, while in the adjusted model group, the sensitivity and the specificity increased to 94.44% and 94.29%, respectively. When using VCR > 20% as the growth metric, the AUC value in the normal and the adjusted model group was 0.856 and 0.947, respectively. The ICC between 2D manual measurements and the 3DRT was 0.95 (95%CI: 0.88-0.98), and the time spent between the two groups had a significant difference (10.96 min vs. 3.44 min, p<0.01, 95% CI, 6.49-8.53). CONCLUSIONS: A 3DRT can be used to determine the growth of the aneurysm more efficiently, intuitively, and accurately.

Health-related quality of life outcomes and influencing factors in patients with unruptured intracranial aneurysms after endovascular treatment.

BACKGROUND: Health-related quality of life (HRQoL) is an important indicator when evaluating prognosis and disease-related treatments. Our current knowledge of the HRQoL outcomes of unruptured intracranial aneurysm (UIA) patients treated by the endovascular intervention appeared to be very limited. To fill this gap, the present study investigated the HRQoL outcomes and identified the influencing factors in UIA patients treated by endovascular intervention. METHODS: We conducted a single-center cross-sectional study on patients who underwent endovascular treatment for UIAs. HRQoL outcomes were assessed by the 36-item Short Form Health Survey (SF-36). The SF-36 results of the Chinese reference population were used as the reference data. The independent variables with a univariate analysis result of P < 0.05 were included in the multivariate analysis. Finally, multivariable linear regression analysis was performed to identify the factors influencing HRQoL. Bonferroni correction was utilized for multiple testing correction. RESULTS: A total of 200 patients (83 males and 117 females, mean age of 55.2 ± 9.48 years) with UIAs treated by endovascular intervention were enrolled. The scores of SF-36 in 8 domains for UIA patients treated by endovascular intervention did not all reach the average level of the Chinese reference population after an average recovery period of 30.67 ± 8.6 months. Ischemic cerebrovascular disease history, advanced age, and mRS progression at discharge were independent risk factors of HRQoL for UIA patients treated by endovascular intervention, but physical exercise at least once a week and daily sleep time no < 6 h were independent protective factors. CONCLUSION: The HRQoL of UIA patients treated by the endovascular intervention was decreased to varying degrees compared with those of the Chinese reference population. The influencing factors of HRQoL explored by this study provide insights for improving the clinical management and daily lives of these patients. HRQoL assessment should be included in future aneurysm prognostic studies to provide better evidence.

Safety and Efficacy of Low-Profile Braided Stents versus Flow Diverters in the Reconstructive Technique in the Treatment of Patients with Vertebrobasilar Dolichoectasia Aneurysms: A Cohort of 47 Patients with Long-Term Follow-Up.

BACKGROUND AND PURPOSE: Vertebrobasilar dolichoectasia aneurysm is a rare type of cerebrovascular disorder with a poor natural history, and endovascular treatment is widely accepted. Whether a high-profile braided stent (flow diverter) could promote occlusion of vertebrobasilar dolichoectasia aneurysm without increasing the complications rather than a low-profile braided stent remains uncertain. The aim of the study was to present a single-center experience of the safety and efficacy of a low-profile braided stent versus a flow diverter in treating patients with vertebrobasilar dolichoectasia aneurysms. MATERIALS AND METHODS: The retrospective review was conducted on a total of 432 consecutive patients diagnosed with posterior circulation aneurysms who underwent endovascular treatment in our center from August 2013 to December 2021. Among these patients, 47 individuals with vertebrobasilar dolichoectasia aneurysms who were treated with low-profile braided stents or flow diverters were included. Vertebrobasilar dolichoectasia aneurysms involving only the vertebral artery were excluded. Patients were divided into 2 groups: the low-profile braided stent group and the flow diverter group based on the device used. Safety and efficacy outcomes were subsequently analyzed. RESULTS: There were 25 total patients enrolled in low-profile braided stent group and 22 patients in flow diverter group. The safety of low-profile braided stents and flow diverters in the treatment of vertebrobasilar dolichoectasia aneurysms was evaluated by clinical outcome, a new neurologic deficit due to procedural complications, and neurologic death. The rates of good clinical outcome were similar between the 2 groups (low-profile braided stent, 56%, versus flow diverter, 59.1%; P = .831), and the rates of neurologic death were also similar (low-profile braided stent, 12%, versus flow diverter, 9.1%; P = .747). Higher rates of new neurologic deficits due to procedural complications were observed in the flow diverter group, but the difference was not significant (low-profile braided stent, 24%, versus flow diverter, 40.9%; P = .215). The efficacy was evaluated by angiographic occlusion of vertebrobasilar dolichoectasia aneurysms and progression of mass effect resulting from these aneurysms. Significantly higher rates of complete occlusion of vertebrobasilar dolichoectasia aneurysms were shown in the flow diverter group (41.2%; P = .028) than in the low-profile braided stent group (10%). CONCLUSIONS: Both low-profile braided stents and flow diverters have similar high risks in reconstructive techniques in the treatment of vertebrobasilar dolichoectasia aneurysms, while a flow diverter is more effective in promoting complete occlusion of vertebrobasilar dolichoectasia aneurysm than a low-profile braided stent. A flow diverter may be a better alternative for carefully selected patients with vertebrobasilar dolichoectasia aneurysms.

Computer-assisted microcatheter shaping for intracranial aneurysm embolization: evaluation of safety and efficacy in a multicenter randomized controlled trial.

BACKGROUND: This study aimed to evaluate the efficacy, stability, and safety of computer-assisted microcatheter shaping (CAMS) in patients with intracranial aneurysms. METHODS: A total of 201 patients with intracranial aneurysms receiving endovascular coiling therapy were continuously recruited and randomly assigned to the CAMS and manual microcatheter shaping (MMS) groups. The investigated outcomes included the first-trial success rate, time to position the microcatheter in aneurysms, rate of successful microcatheter placement within 5 min, delivery times, microcatheter stability, and delivery performance. RESULTS: The rates of first-trial success (96.0% vs 66.0%, P<0.001), successful microcatheter placement within 5 min (96.04% vs 72.00%, P<0.001), microcatheter stability (97.03% vs 84.00%, P=0.002), and 'excellent' delivery performance (45.54% vs 24.00%, P<0.001) in the CAMS group were significantly higher than those in the MMS group. Additionally, the total microcatheter delivery and positioning time (1.05 minutes (0.26) vs 1.53 minutes (1.00)) was significantly shorter in the CAMS group than in the MMS group (P<0.001). Computer assistance (OR 14.464; 95% CI 4.733 to 44.207; P<0.001) and inflow angle (OR 1.014; 95% CI 1.002 to 1.025; P=0.021) were independent predictors of the first-trial success rate. CAMS could decrease the time of microcatheter position compared with MMS, whether for junior or senior surgeons (P<0.001). Moreover, computer assistance technology may be more helpful in treating aneurysms with acute angles (p<0.001). CONCLUSIONS: The use of computer-assisted procedures can enhance the efficacy, stability, and safety of surgical plans for coiling intracranial aneurysms.

Clinical, 3D Morphological, and Hemodynamic Risk Factors for Instability of Unruptured Intracranial Aneurysms.

PURPOSE: Neurosurgeons can manage unruptured intracranial aneurysms (UIAs). However, the stability of UIAs under follow-up remains uncertain. This study aimed to examine the risk factors associated with the instability (rupture or growth) of UIAs during follow-up. METHODS: We obtained information on patients with UIA who underwent ≥ 6 months of the time of flight-magnetic resonance angiography (TOF-MRA) imaging follow-up in two centers. Computer-assisted semi-automated measurement (CASAM) techniques were used for recording morphological parameters and determining the growth of these aneurysms. We also recorded hemodynamic parameters at the beginning of the follow-up. The univariate and multivariate Cox regression analyses were performed to calculate hazard ratios with corresponding 95% confidence intervals for the clinical, morphological, and hemodynamic risk factors for aneurysm instability. RESULTS: A total of 304 aneurysms from 263 patients (80.4%) were included for analysis. The annual aneurysm growth rate was 4.7%. Significant predictive factors for aneurysm instability in the multivariate analysis were as follows: poorly controlled hypertension (hazard ratio (HR), 2.97 (95% CI, 1.27-6.98), P = 0.012); aneurysms located on posterior circulation (HR, 7.81 (95% CI, 2.28-26.73), P = 0.001), posterior communication artery (HR, 3.01 (95% CI, 1.07-8.46), P = 0.036), and cavernous carotid artery (HR, 3.78 (95% CI, 1.18-12.17), P = 0.026); and size ratio ≥ 0.87 (HR, 2.54 (95% CI, 1.14-5.68), P = 0.023). CONCLUSIONS: The management of UIAs should focus on the control of hypertension during the follow-up. Aneurysms on the posterior communicating artery, posterior circulation, and cavernous carotid arteries require intensive surveillance or timely treatment.

Analysis of the wall thickness of intracranial aneurysms: Can computational fluid dynamics detect the translucent areas of saccular intracranial aneurysms and predict the rupture risk preoperatively?

Background and purpose: The translucent area on the surface of intracranial aneurysms (IAs) is associated with rupture risk. In the present study, the Polyflow module of the Ansys software was used to simulate and analyze the thickness of the aneurysm wall to detect whether it was "translucent" and to assess the rupture risk. Methods: Forty-five patients with 48 IAs who underwent microsurgery were retrospectively reviewed. The medical records, radiographic data, and intraoperative images of the patients were collected. The image data were analyzed using computational fluid dynamics (CFD) simulations to explore the relationship between the simulated thickness of the aneurysm wall, the translucent area, and the rupture point of the real aneurysm's surface to predict the rupture risk and provide a certain reference basis for clinical treatment. Results: The Polyflow simulation revealed that the location of the minimum extreme point of the simulated aneurysm wall thickness was consistent with the translucent area or rupture point on the surface of the real aneurysm. There was a downward trend in the correlation between the change rate (IS) in the wall area and volume during aneurysm growth and rupture. Ruptured aneurysms have a greater inhomogeneity coefficient Iδ than the unruptured ones. In the unruptured group, translucent aneurysms also had greater inhomogeneity coefficients Iδ and more significant thickness changes (multiple IBA) than non-translucent ones. Conclusions: The Ansys software Polyflow module could detect whether the unruptured aneurysms were translucent and predict the rupture risk and rupture point. Clinical trial registration: https://clinicaltrials.gov/, Identifier, NCT03133624.

Application of deblur technology for improving the clarity of digital subtractive angiography.

BACKGROUND: Digital subtraction angiography (DSA) is most commonly used in vessel disease examinations and treatments. We aimed to develop a novel deep learning-based method to deblur the large focal spot DSA images, so as to obtain a clearer and sharper cerebrovascular DSA image. METHODS: The proposed network cascaded several residual dense blocks (RDBs), which contain dense connected layers and local residual learning. Several loss functions for image restoration were investigated. Our training set consisted of 52 paired images of angiography with more than 350,000 cropped patches. The testing set included 10 body phantoms and 80 clinical images of different types of diseases for subjective evaluation. All test images were acquired using a large focal spot, and phantom images were simultaneously acquired using a micro focal spot as ground-truth. Peak-to-noise ratio (PSNR) and structural similarity (SSIM) were determined for quantitative analysis. The deblurring results were compared with the original data, and the image quality was subjectively evaluated and graded by two clinicians. RESULTS: For quantitative analysis of phantom images, the average PSNR/SSIM based on the deep-learning approach (35.34/0.9566) was better than that of large focal spot images (30.64/0.9163). For subjective evaluation of 80 clinical patient images, image quality in all types of cerebrovascular diseases was also improved based on a deep-learning approach (p < 0.001). CONCLUSIONS: Deep learning-based focal spot deblur algorithm can efficiently improve DSA image quality for better visualization of blood vessels and lesions in the image.

Risk Factors for Pericallosal Artery Aneurysm Rupture Based on Morphological Computer-Assisted Semiautomated Measurement and Hemodynamic Analysis.

Background: Although pericallosal artery aneurysms (PAAs) are relatively uncommon, accounting for only 1-9% of all intracranial aneurysms (IAs), they exhibit a considerably high propensity to rupture. Nevertheless, our current knowledge of the risk factors for PAA rupture is still very limited. To fill this gap, we investigated rupture risk factors for PAAs based on morphological computer-assisted semiautomated measurement (CASAM) and hemodynamic analysis. Methods: Patients with PAAs were selected from the IA database in our institute and their baseline data were collected. Morphological parameters were measured in all enrolled patients by applying CASAM. Computational fluid dynamics simulation (CFD) was performed to evaluate the hemodynamic difference between ruptured and unruptured PAAs. Results: From June 2017 to June 2020, among 2141 patients with IAs in our institute, 47 had PAAs (2.2%). Thirty-one patients (mean age 57.65 ± 9.97 years) with 32 PAAs (20 unruptured and 12 ruptured) were included in the final analysis. Comparing with unruptured PAAs, ruptured PAAs had significantly higher aspect ratio (AR), mean normalized wall shear stress (NWSS), and mean oscillatory shear index (OSI) values than the unruptured PAAs (all P < 0.05) in univariate analyses. Multivariable analysis showed that a high mean OSI was an independent risk factor for PAA rupture (OR = 6.45, 95% CI 1.37-30.32, P = 0.018). Conclusion: This preliminary study indicates that there are morphological and hemodynamic differences between ruptured and unruptured PAAs. In particular, a high mean OSI is an independent risk factor for PAA rupture. Further research with a larger sample size is warranted in the future.

The sensitivity and specificity of TOF-MRA compared with DSA in the follow-up of treated intracranial aneurysms.

BACKGROUND: Time-of-flight magnetic resonance angiography (TOF-MRA) is widely used in detecting intracranial aneurysms (IA), but it is limited and controversial for use during follow-up to assess the outcome of interventional coiling or clipping surgery. METHODS: To evaluate the specificity and sensitivity of using TOF-MRA as an imaging follow-up for IA with different treatments. A total of 280 patients with 326 treated IA underwent simultaneous TOF-MRA and digital subtraction angiography (DSA) as follow-up imaging on the same day. All images were independently reviewed by two neurosurgeons and two radiologists. The consensus evaluation of intra-arterial DSA as a reference test was used to evaluate the result of aneurysm occlusions. The aneurysmal embolization status was assessed with two ratings involving complete or incomplete occlusions. We calculated the sensitivity, specificity, negative predictive value, and positive predictive value of three-dimensional-TOF-MRA to investigate the diagnostic performance. RESULTS: Overall sensitivity and specificity of TOF-MRA for diagnosing the remnant were 83.3% and 95.2%, respectively. The sensitivity and specificity of interventional therapy was 90.0% and 94.2%, respectively, while the clipping group showed sensitivity and specificity of 50.0% and 100%, respectively. For additional groups, involving coil only, stent-assisted, and flow diverter, the analysis of interventional therapy showed sensitivities and specificities of 100.0% and 90.1%, 66.7% and 95.1%, and 91.7% and 100%, respectively. CONCLUSIONS: TOF-MRA can be used as a first-line noninvasive imaging modality during follow-up, especially for the patients treated with a pipeline embolization device and coils only. But it may not be enough for clipped aneurysms.

Microsurgical and Endovascular Treatment Outcomes in Pericallosal Artery Aneurysms: A Single Center Retrospective Analysis.

AIM: To summarize the clinical outcomes, follow-up results and to discuss the optimal therapeutic strategy for pericallosal artery aneurysms (PAAs). MATERIAL AND METHODS: From January 2013 to May 2017, the charts of 49 patients with PAAs, representing 2.43% of 2,018 consecutive patients with intracranial aneurysms (IAs) were reviewed. The clinical and radiological data of these patients were retrospectively analyzed. RESULTS: There were no technical failures in the clipping group, but one patient in the coiling group presented rebleeding during the operation, resulting in a poor prognosis. Although the difference was not significant, the coiling group had a better complete recovery rate than the clipping group [overall: coiling, n=20 (87.0%) vs clipping, n=11 (68.8%), p=0.33; unruptured PAAs: coiling, n=12 (92.3%) vs clipping, n=5 (83.3%); ruptured PAAs: coiling, n=8 (80%) vs clipping, n=6 (60%), p=0.63]. One patient in the coiling group exhibited recurrence. No patients experienced rebleeding during the follow-up period in either group. CONCLUSION: In our study, both endovascular coiling and microsurgery were technically feasible and achieved favorable clinical outcomes in patients with PAAs. Longer radiological follow-up is necessary. Patients should be evaluated by a multidisciplinary team prior to determining the optimal treatment modality.

Fully automated intracranial aneurysm detection and segmentation from digital subtraction angiography series using an end-to-end spatiotemporal deep neural network.

BACKGROUND: Intracranial aneurysms (IAs) are common in the population and may cause death. OBJECTIVE: To develop a new fully automated detection and segmentation deep neural network based framework to assist neurologists in evaluating and contouring intracranial aneurysms from 2D+time digital subtraction angiography (DSA) sequences during diagnosis. METHODS: The network structure is based on a general U-shaped design for medical image segmentation and detection. The network includes a fully convolutional technique to detect aneurysms in high-resolution DSA frames. In addition, a bidirectional convolutional long short-term memory module is introduced at each level of the network to capture the change in contrast medium flow across the 2D DSA frames. The resulting network incorporates both spatial and temporal information from DSA sequences and can be trained end-to-end. Furthermore, deep supervision was implemented to help the network converge. The proposed network structure was trained with 2269 DSA sequences from 347 patients with IAs. After that, the system was evaluated on a blind test set with 947 DSA sequences from 146 patients. RESULTS: Of the 354 aneurysms, 316 (89.3%) were successfully detected, corresponding to a patient level sensitivity of 97.7% at an average false positive number of 3.77 per sequence. The system runs for less than one second per sequence with an average dice coefficient score of 0.533. CONCLUSIONS: This deep neural network assists in successfully detecting and segmenting aneurysms from 2D DSA sequences, and can be used in clinical practice.

Accuracy and reliability of computer-assisted semi-automated morphological analysis of intracranial aneurysms: an experimental study with digital phantoms and clinical aneurysm cases.

PURPOSE: Morphological parameters are very important for predicting aneurysm rupture. However, due to geometric radiographic distortion and plane/angle selection bias, the traditional manual measurements (MM) of aneurysm morphology are inaccurate and suffer from severe variability. Our study is to evaluate the accuracy and reliability of computer-assisted semi-automated measurement (CASAM) of intracranial aneurysms, which is a novel technique in aneurysm measurement. METHODS: An in-house software for CASAM was developed. Classical morphology indices including aneurysm diameter, neck size, height, width, volume, inflow angle, and aspect ratio were measured. To validate the accuracy and robustness of the semi-automated measurements, 20 digital intracranial aneurysm phantoms and 27 clinical aneurysms with different locations and sizes were measured using MM or CASAM. RESULTS: In the phantom study, although the inter-observer variability of both the MM and CASAM was very low, the manual measurements had higher errors (1.7-19.1%), while the CASAM yielded more accurate results (errors of 1.1-2.5%). The consistency test indicated that the CASAM results were highly consistent with the actual values (concordance correlation coefficient = 0.993). In the clinical study, CASAM showed better intraclass correlation coefficient values compared with MM. The inflow angle had low consistency in both groups. CONCLUSIONS: We successfully developed a computer-assisted method to semi-automatically measure the morphological parameters of aneurysm. According to our study, CASAM of aneurysm morphological parameters is a more precise and reliable way than MM to obtain accurate aneurysm morphological parameters. This method is worthy of further studies to promote its clinical use.

Endovascular treatment of V3 segment vertebro-vertebral arteriovenous fistula with Willis covered stent: Case report and literature review.

A 46-year-old male presented to our hospital suffering from right mastoid pulsatile tinnitus secondary to traffic trauma. Digital subtraction angiography was remarkable for a vertebro-vertebral arteriovenous fistula fed by the right vertebral artery at the C1 level. Dual platelet therapy was administrated before and after the operation, then a Willis covered stent was deployed at the orifice of the fistula. Post-operative angiography showed proper stent localization but some contrast agent leaking from the fistula. Angiography performed 6 months post-operatively demonstrated no leak from the fistula and the patency of the right vertebral artery. This case demonstrated that an intracranial covered stent could be used as an alternative, successful treatment for vertebro-vertebral arteriovenous fistula.