Relationship between Aging and Enlargement of Intracranial Aneurysms

Single-cell analysis reveals the implication of vascular endothelial cell-intrinsic ANGPT2 in human intracranial aneurysm

AIMS

While previous single-cell RNA sequencing (scRNA-seq) studies have attempted to dissect intracranial aneurysm (IA), the primary molecular mechanism for IA pathogenesis remains unknown. Here, we uncovered the alterations of cellular compositions, especially the transcriptome changes of vascular endothelial cells (ECs), in human IA.

METHODS AND RESULTS

We performed scRNA-seq to compare the cell atlas of sporadic IA and the control artery. The transcriptomes of 43 462 cells were profiled for further analysis. In general, IA had increased immune cells (T/NK cells, B cells, myeloid cells, mast cells, neutrophils) and fewer vascular cells (ECs, vascular smooth muscle cells, and fibroblasts). Based on the obtained high-quantity and high-quality EC data, we found genes associated with angiogenesis in ECs from IA patients. By EC-specific expression of candidate genes in vivo, we observed the involvement of angpt2a in causing cerebral vascular abnormality. Furthermore, an IA zebrafish model mimicking the main features of human IA was generated through targeting pdgfrb gene, and knockdown of angpt2a alleviated the vascular dilation in the IA zebrafish model.

CONCLUSION

By performing a landscape view of the single-cell transcriptomes of IA and the control artery, we contribute to a deeper understanding of the cellular composition and the molecular changes of ECs in IA. The implication of angiogenic regulator ANGPT2 in IA formation and progression, provides a novel potential therapeutical target for IA interventions.

Endovascular Treatment of Unruptured Wide Necked Cerebral Aneurysms Larger Than 9 mm Affects Re-treatment and Prognosis in the Elderly: A Retrospective Analysis of Unruptured Aneurysms

Background and purpose The risk of rupture increases with advancing age. However, the risk-benefit of coil embolization for elderly patients with unruptured aneurysms is controversial. This study aimed to identify factors associated with treatment primary outcomes, including risk factors for complications and aneurysm recurrence requiring re-treatment in the endovascular treatment of unruptured aneurysms in elderly patients. In addition, deterioration of the modified Rankin Scale (mRS) was examined as a secondary outcome. Materials and methods This retrospective three-center study examined 112 cases of coiled unruptured aneurysms in patients aged ≥ 60 years using endovascular registry data from January 2018 to March 2022. We examined patient background, aneurysm characteristics, adjuvant technique, symptomatic complications, and mRS scores. Results The average age of the patients was 72.5±6.9 years, and 83 cases (74.1%) were female. During the postoperative follow-up period (six to 36 months), no deaths occurred, one case of postoperative rupture was observed, and nine patients (5.4%) were re-treated. Notably, age, underlying disease, aneurysm location, and re-treatment were not associated with complications. In the multivariate logistic analysis for re-treatment, symptomatic complications [odds ratio (OR) 11.01; 95% confidence interval (CI), 3.68-52.5; p < 0.001] and re-treatment (OR 3.25; 95% CI, 1.04-10.7; p = 0.039) were independently associated with mRS score deterioration. The risk factors for re-treatment were maximum aneurysm diameter and aneurysm neck diameter; aneurysms with neck diameters and maximum diameters > 5.0 mm and > 9.0 mm, respectively, had a higher rate of need for re-treatment (33%) and mRS score deterioration (33%) due to re-enlargement of the aneurysm. Conclusion In this study, complications did not increase with age in those aged 60 and older. However, prioritizing the avoidance of complications in elderly patients is important. Elderly patients with aneurysms larger than 9 mm have a poor prognosis and require additional attention for re-treatment.

Artificial Intelligence in Neurosurgery: A State-of-the-Art Review from Past to Future

In recent years, there has been a significant surge in discussions surrounding artificial intelligence (AI), along with a corresponding increase in its practical applications in various facets of everyday life, including the medical industry. Notably, even in the highly specialized realm of neurosurgery, AI has been utilized for differential diagnosis, pre-operative evaluation, and improving surgical precision. Many of these applications have begun to mitigate risks of intraoperative and postoperative complications and post-operative care. This article aims to present an overview of the principal published papers on the significant themes of tumor, spine, epilepsy, and vascular issues, wherein AI has been applied to assess its potential applications within neurosurgery. The method involved identifying high-cited seminal papers using PubMed and Google Scholar, conducting a comprehensive review of various study types, and summarizing machine learning applications to enhance understanding among clinicians for future utilization. Recent studies demonstrate that machine learning (ML) holds significant potential in neuro-oncological care, spine surgery, epilepsy management, and other neurosurgical applications. ML techniques have proven effective in tumor identification, surgical outcomes prediction, seizure outcome prediction, aneurysm prediction, and more, highlighting its broad impact and potential in improving patient management and outcomes in neurosurgery. This review will encompass the current state of research, as well as predictions for the future of AI within neurosurgery.

Recent Declining Trend of Incidence Rate of Subarachnoid Hemorrhage in Shimane, Japan: The Japan Incidence of Subarachnoid Hemorrhage (JIS) Study

The “Izumo Study” revealed the incidence rate of subarachnoid hemorrhage (SAH) in Izumo City, Shimane Prefecture, Japan, from 1980 to 1998. However, no study has been published regarding the incidence of SAH in Shimane Prefecture after 1998. Most studies reporting the incidence of SAH in Japan have been conducted before 2000, although a few have been reported after 2000. This study aimed to assess the estimated age-adjusted incidence rate (AAIR) of SAH in Shimane Prefecture after 1998, following the Izumo Study. A retrospective study was conducted to identify the estimated AAIR of SAH in Shimane Prefecture, using the age-adjusted SAH mortality rate for this population from 1999 to 2017 and assuming that the case-fatality rate of SAH decreased by 0.7% annually from 45% in 1999 to 32.4% in 2017. We used linear regression analysis for trend to the estimated AAIR of SAH. Sensitivity analyses were also conducted by various case-fatality rates of SAH using assuming case-fatality rate based on previous reports. The estimated AAIR of SAH in Shimane Prefecture declined from 33.6 (95% confidence interval [CI]: 29.7-37.9) per 100,000 person-years in 1999, by 26.5%, to 24.7 (95% CI: 21.4-28.5) in 2017 (p < 0.01, r = 0.58). Declining trend of incidence rate of SAH in Shimane Prefecture from 1999 to 2017 was confirmed in this study.

Aging Changes of Aneurysmal Subarachnoid Hemorrhage: A 35-year, Hospital-Based Study

BACKGROUND

The etiology and background factors which cause decreases in the size of ruptured intracranial aneurysms remain unclear.

OBJECTIVE

To clarify the age- and sex-related differences in aneurysmal subarachnoid hemorrhage (SAH) based on a 35-year-old hospital database and demographic data.

METHODS

A database of patients admitted to our hospital with aneurysmal SAH from 1983 to 2017 was split into 5-year intervals and analyzed. Demographic data of the general population were also analyzed for reference.

RESULTS

Altogether, 1,523 aneurysmal SAH events were enrolled in the analysis. Age (p<0.001), proportion of elderly patients ≥ 65 years old (p<0.001), female sex (p=0.005), very small aneurysms less than 5 mm (p<0.001), and the yearly-averaged number of fatal events showed increasing trends. The proportion of aneurysm size of 10 mm or more (p = 0.011) and the yearly-averaged population of Shimane prefecture (p < 0.001) showed declining trends. In the subgroup analyses, the proportion of very small aneurysms was found to increase significantly in the non-elderly male and elderly female subgroups. The proportion of large aneurysms (10 mm or more) decreased in the non-elderly subgroup (p<0.05). As for the elderly subgroups, the yearly-averaged number of events did not show a significant tendency, although the yearly-averaged population of Shimane prefecture showed an increasing trend.

CONCLUSION

We found an increasing trend in the prevalence of very small aneurysms in elderly females. Recent aging may contribute to this trend. The number of aneurysmal SAH events was confirmed to not increase, despite the increased aging population of Shimane prefecture.

Effect of age on outcomes and practice patterns for patients with anterior communicating artery aneurysms

BACKGROUND

With widespread utilization of noninvasive imaging, small unruptured anterior communicating artery (AcoA) aneurysms are increasingly detected in the general population, particularly in elderly patients. We investigated the association between age and clinical characteristics and outcomes of patients with unruptured AcoA aneurysms.

METHODS

Between January 2008 and May 2016, information on 179 consecutive patients with unruptured AcoA aneurysms was obtained and included demographic data, aneurysm features, risk factors for formation and rupture, treatment type, complications, and follow-up information. A 2-tailed t test was used for continuous data and the chi-square test for categorical variables. Statistical significance was set at P value < 0.05.

RESULTS

There were 76 patients 65 and older (42.5%) and 103 younger than 65 (57.5%). Conservative management was more common in older patients (67.1% vs. 41.7%, P=0.001). Endovascular treatment was more commonly used in the older population (80% vs. 61% of the treated aneurysms in older and younger group, P=0.16). Treatment-related complications were 8% but resulted in permanent neurological deficits in one patient (1.2%). Among conservatively treated aneurysms, three (3.2%) ruptured at follow-up resulting in patient death in two cases (2.4%). All three ruptures occurred in elderly patients.

CONCLUSIONS

With a modern approach that emphasizes endovascular therapy, especially in older individuals, unruptured AcoA aneurysms can be treated with a very low morbidity. Among patients with small aneurysms for which treatment was not deemed indicated or necessary, the rate of rupture at follow-up was not negligible, with 5.8% of older patients experiencing bleeding from the aneurysm.