Comparison of platinum and first-generation Matrix coils in under-packed canine side-wall aneurysms: evaluation of progressive thrombosis

Growth of unruptured aneurysms: A meta-analysis of natural history and endovascular studies

The growth of unruptured intracranial aneurysms (UIAs) is a strong predictor of rupture. Clinical observations suggest that some UIAs might grow faster after endovascular treatment than untreated UIAs. There are no head-to-head comparisons of incidence rates of UIAs thus far.

METHODS

We searched PubMed, Embase and Google Scholar for relevant articles from the inception of the databases to March 2020. We pooled and compared the incidence rates for the growth of aneurysms from natural history studies and endovascular treatment studies. Generalized linear models were used for confounder adjustment for the prespecified confounders age, size and location.

RESULTS

Twenty-five studies (10 describing growth in natural history and 15 reporting growth after endovascular therapy) considering 6325 aneurysms were included in the meta-analysis. The median size of aneurysms was 3.7 mm in the natural history studies and 6.4 mm in endovascular treatment studies (p = 0.001). The pooled incidence rate (IR) of growth was significantly higher in endovascular treatment studies (IR 52 per 1000 person-years, with a 95% confidence interval (CI) 36-79) compared to natural history studies (IR 28 per 1000 person-years, 95% CI 17 - 46, p-value < 0.01) after adjustment for confounders.

CONCLUSION

Our results suggest that the incidence rate of cerebral aneurysm growth might be higher after endovascular therapy than the incidence rates reported in natural history studies. These results should be viewed in light of the risk of bias of the individual studies and the risk of ecological bias.

Endovascular treatment of cerebral aneurysms in relation to their parent artery wall: a single center study

We report our two-year experience in the endovascular treatment of brain aneurysms in relation to their parent artery wall. We prospectively recorded patients with intracranial aneurysms (107 ruptured - 38 unruptured) treated with coiling during a two-year period: 145 patients, 94 females and 51 males - mean age 56 years. The aneurysms were divided into side-wall (A) and bifurcation (B) groups. A total occlusion rate was noted in post-embolization angiograms in 101 aneurysms (70%) with a morbidity of 4%. No angiographic recurrence arose in the six-month follow-up. The two groups had a similar total occlusion rate (68.31% and 71.8% respectively), while the complication rate was 3% in group A and 4.7% in group B. Significant differences between the two groups were noted in the number of assisted coiling cases: 28 out of 60 cases (46.7%) in group A - 14 out of 85 cases (16.5%) in group B. Further statistical analysis showed strong dependencies for the type of endovascular procedure between the ruptured and unruptured aneurysms in both groups (p 0.000<0.05), but no dependencies between the aneurysm occlusion rate and the ruptured or non-ruptured aneurysms, or between the occlusion rate and the type of endovascular procedure (p 0.552>0.05 and 0.071>0.05 respectively). In conclusion, the anatomic relation of the aneurysm sac with the wall of the parent artery is important, as significant differences in endovascular practice, devices and techniques were noted between side-wall and bifurcation aneurysms.

Creation of sidewall aneurysm in rabbits: aneurysm patency and growth follow-up

INTRODUCTION

To explore the patency and growth of surgical sidewall aneurysms in rabbits.

MATERIALS AND METHODS

Forty sidewall aneurysms were created in the right common carotid artery (RCCA). Intravenous digital subtraction angiography (DSA) through the ear vein was performed immediately after creation. Three weeks later, intra-arterial DSA through the femoral artery was performed. Aneurysm sizes (neck, width, height and volume) were measured and calculated immediately after creation and 3 weeks later. Aneurysm patency after creation was evaluated. Differences in aneurysm sizes immediately after creation and 3 weeks later were compared using the Student's t test.

RESULTS

Aneurysms and the parent artery remained patent in 38 (95%) of the 40 rabbits 3 weeks after creation. Two other rabbits (5%) showed aneurysm occlusion. There was a significant difference in aneurysm neck size 3 weeks after creation (3.6±0.9 mm vs 2.4±0.4 mm, p<0.0001). The aneurysm became wider 3 weeks later (5.8±1.5 mm vs 4.3±1.2 mm, p<0.0001). Aneurysm length was also larger than immediately after creation (6.1±1.3 mm vs 4.3±1.4 mm, p<0.0001). The aneurysm volume was larger than that created immediately (127.5±89.4 mm(3) vs 51.0±34.9 mm(3), p<0.0001).

CONCLUSIONS

The patency rate of sidewall aneurysms in rabbits is high. The aneurysm keeps growing for at least 3 weeks after creation.