Importance of the First Coil in the Embolization of Intracranial Aneurysms : A Case Control Study

Exploring the Landscape of Intracranial Aneurysms in South America: A Comprehensive Narrative Review Intracranial Aneurysms in South America

Exploring the landscape of intracranial aneurysms in South America unravels a complex interplay of epidemiological factors, clinical manifestations, and therapeutic challenges. The study methodically conducts a comprehensive literature review spanning the years 2003 to 2023, focusing on English-language articles obtained from diverse databases to elucidate the multifaceted nature of intracranial aneurysms in the region. Results and discussions categorize outcomes into positive domains, emphasizing successful treatments, favorable recoveries, and high survival rates, while also shedding light on negative aspects such as residual aneurysms and complications. The research illuminates significant gaps in pathological typing of intracranial aneurysms and exposes challenges in healthcare accessibility, notably the disparities in neurosurgical resources. Management challenges, including constrained infrastructure access, a neurosurgeon shortage, and gender disparities, are underscored. Transitioning to future prospects, the study advocates for strategic interventions, proposing expanded neurosurgical training, multidisciplinary approaches, improved funding, enhanced access to care, and fostering international collaborations. The study concludes by emphasizing the pivotal role of collaborative efforts, intensified training programs, and global partnerships in propelling intracranial aneurysm management forward in South America, ultimately contributing to enhanced patient outcomes across the region.

A deep-learning system to help make the surgical planning of coil embolization for unruptured intracranial aneurysms

BACKGROUND

Coil embolization is a common method for treating unruptured intracranial aneurysms (UIAs). To effectively perform coil embolization for UIAs, clinicians must undergo extensive training with the assistance of senior physicians over an extended period. This study aimed to establish a deep-learning system for measuring the morphological features of UIAs and help the surgical planning of coil embolization for UIAs.

METHODS

Preoperative computational tomography angiography (CTA) data and surgical data from UIA patients receiving coil embolization in our medical institution were retrospectively reviewed. A convolutional neural network (CNN) model was trained on the preoperative CTA data, and the morphological features of UIAs were measured automatically using this CNN model. The intraclass correlation coefficient (ICC) was utilized to examine the similarity between the morphologies measured by the CNN model and those determined by experienced clinicians. A deep neural network model to determine the diameter of first coil was further established based on the CNN model within the derivation set (75% of all patients) using neural factorization machines (NFM) model and was validated using a validation set (25% of all patients). The general match ratio (the difference was within ± 1 mm) between the predicted diameter of first coil by model and that used in practical scenario was calculated.

RESULTS

One-hundred fifty-three UIA patients were enrolled in this study. The CNN model could diagnose UIAs with an accuracy of 0.97. The performance of this CNN model in measuring the morphological features of UIAs (i.e., size, height, neck diameter, dome diameter, and volume) was comparable to the accuracy of senior clinicians (all ICC > 0.85). The diameter of first coil predicted by the model established based on CNN model and the diameter of first coil used actually exhibited a high general match ratio (0.90) within the derivation set. Moreover, the model performed well in recommending the diameter of first coil within the validation set (general match ratio as 0.91).

CONCLUSION

This study presents a deep-learning system which can help to improve surgical planning of coil embolization for UIAs.

Development of Machine Learning Model for Selecting the 1st Coil in the Treatment of Cerebral Aneurysms by Coil Embolization

To achieve good treatment outcomes in coil embolization for cerebral aneurysms, it is important to select an appropriate 1st coil for each aneurysm since it serves as a frame to support the subsequent coils to be deployed. However, its selection as appropriate size and length from a wide variety of lineups is not easy, especially for inexperienced neurosurgeons. We developed a machine learning model (MLM) to predict the optimal size and length of the 1st coil by learning information on patients and aneurysms that were previously treated with coil embolization successfully. The accuracy rates of the MLM for the test data were 86.3% and 83.4% in the prediction of size and length, respectively. In addition, the accuracy rates for the 30 cases showed good prediction by the MLM when compared with two different skilled neurosurgeons. Although the accuracy rate of the well-experienced neurosurgeon is similar to MLM, the inexperienced neurosurgeon showed a worse rate and can benefit from the method.Clinical Relevance- The developed MLM has the potential to assist in the selection of the 1st coil for aneurysms. A technically and cost efficient supply chain in the treatment of aneurysms may also be achieved by MLM application.

Real-Time Monitoring of Aneurysm Catheterization During Stent-Assisted Coiling for Irregularly Shaped Intracranial Aneurysms: The Scope Technique

OBJECTIVE

Stent-assisted coiling (SAC) using the jailing technique is a well-established treatment for wide-neck intracranial aneurysms. However, low-volume packing, which is a key factor for aneurysm recanalization, can occur in patients with irregularly shaped aneurysms. We have devised a real-time monitoring system for aneurysm catheterization that allows the intentional placement of the jailed coil-delivery microcatheter and deployed stent, referred to as the "scope" technique. Herein, we present a case of irregularly shaped anterior communicating artery (ACoA) aneurysm successfully treated with SAC using this technique.

METHODS

A 72-year-old woman diagnosed with an unruptured wide-neck ACoA aneurysm that was eccentric to the parent ACoA and overhanging posteriorly underwent SAC using this technique. Bilateral transradial quadraxial systems (6-Fr Simmons guiding sheath/6-Fr intermediate catheter/3.2-Fr intermediate catheter/microcatheter) were established via right and left internal carotid artery. The stent-delivery microcatheter was advanced into the left A2 via the right A1, leaving a 0.014″ microguidewire for visualization under fluoroscopic guidance. To place the coil-delivery microcatheter in the middle of the aneurysm after stent deployment, the coil-delivery microcatheter was cannulated into the aneurysm via the left A1, intendedly through the posterior side of the stent-delivery microcatheter in the down-the-barrel view of the parent ACoA (the scope technique).

RESULTS

After stent deployment, SAC of the aneurysm was successfully achieved.

CONCLUSIONS

Using this technique, the coil-delivery microcatheter was cannulated into the aneurysm, while monitoring its positional relationship with the stent-delivery microcatheter in real time. This technique is a useful treatment option for irregularly shaped and wide-neck aneurysms.

Packing density and the angiographic results of coil embolization of intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

Endovascular coil embolization (ECE) for intracranial aneurysms has been proven as an effective minimally invasive treatment. However, the aneurysm recanalization after coiling is a serious complication of this technique. Among all the proposed factors associated with recanalization, the impact of packing density (PD) is still controversial.

OBJECTIVE

To clarify the role of PD in the aneurysm recanalization following ECE, via conducting a systematic review and meta-analysis.

METHODS

A systematic literature search was conducted using PubMed, Scopus, Embase, and Web of Science databases, until November 28, 2022, by adhering to the Preferred Reporting Items for Systematic Review and Meta-Analyses statement guidelines. Considering the eligibility criteria, all the studies reporting the outcomes of interest were included. Data elements of interest were extracted and analyzed using R software version 4.2.1.

RESULTS

The pooled analysis of the 17 eligible papers revealed a 29% higher PD of the nonrecanalized aneurysms (ROM = 1.29, 95% confidence interval [CI] = 1.18-1.40, p < 0.001), even after removing outlier studies to reduce heterogeneity. However, the pooled estimates from multivariable regression models within nine included studies showed no significant effect of PD on recanalization odds when incorporated into a multivariable model with other predictors (odds ratio [OR] = 0.93, 95% CI = 0.84-1.02, p = 0.126), even after removing outlier studies.

CONCLUSION

The current literature does not support PD as a significant predictor of aneurysm treatment outcomes, especially with adjusting for other variables. This finding necessitates further prospective multicenter studies with a larger sample size to overcome the current methodological shortcomings.

Assessment of balloon remodeling techniques in endovascular treatment of wide-neck intracranial aneurysms (WN-IAs)

OBJECTIVES

To evaluate the clinical, technical, and angiographic results in endovascular management of wide-neck intracranial aneurysms (WN-IAs) using the balloon-remodeling technique.

METHODS

This study was a prospective, single-center study that was carried out over a period of three years from January 2019 to December 2021 at the Neuro-Interventional Unit at our hospital. Patients who presented with WNIAs and were eligible for endovascular treatment using the balloon-remodeling approach were included in the study.

RESULTS

We included 37 patients with a mean age of 49.7 ± 12.3 years. About 91.9% of the participants had SAH, 5.4% had unruptured aneurysms, and 2.7% had intracranial hemorrhage. The mean time to treatment was 6.97 ± 7.35 days, the mean aneurysm diameter was 5.7 ± 1.7 mm, and the mean neck diameter was 3.8 ± 1.0 mm. The majority of the patients had a dom-to-neck ratio of less than 2 (89.2%). We have used hyper form balloons in 48.6%, hyper glide in 43.2%, Copernic balloons in 5.4%, and eclipse in 2.7%. According to the Raymond-Roy occlusion classification, 86.5% of the patients had complete obliteration, 10.8% had residual neck, and 2.7% had a residual aneurysm. Almost 91.9% had no complications, 2.7% had ischemia, and 5.4% had mild rupture by wire, treated by 5 min hyperinflation of the balloon till hemorrhage stopped.

CONCLUSIONS

Balloon-assisted detachable coiling is an important option in the treatment of WN-IAs. We found that this technique allowed safe and efficient treatment of aneurysms when conventional treatment had failed due to WN. Endovascular coiling using the balloon remodeling technique of wide neck showed a high technical success rate and good short-term clinical outcomes. A good selection of patients with WN-IAs treated by endovascular coiling using balloon remodeling technique and a good selection of materials used help in decreasing the complications.

Evaluation of Contact Force between Aneurysm Model and Coil for Embolization of Intracranial Aneurysms

Objective

To ensure safe coil embolization for intracranial aneurysms, it is important to investigate the contact force between the coil and the aneurysm wall. However, it is unclear how the catheter tip position and the diameter of the secondary loop of the coil influence the contact force. In this study, we measured the contact force between a coil and an aneurysm biomodel under different conditions.

Methods

A commercially available coil was inserted through a microcatheter into a silicone rubber aneurysm model at a constant speed (1 mm/s) using an automatic stage, and the contact force between the coil and the aneurysm wall was measured by a force sensor attached on the aneurysm model. The inner diameter of the spherical aneurysm was 5 mm. The effects of varying the position of the catheter tip (near dome, center, near neck) and the diameter of the secondary coil (4.5 mm) were evaluated.

Results

When the catheter tip was inserted more deeply into the aneurysm (especially near the dome), the contact force increased. The contact force also increased as the secondary coil diameter was increased with the catheter tip near and in the center of the dome.

Conclusion

These results suggest that the catheter tip position and the secondary coil diameter affect the contact force. In particular, the contact force should be considered large with the catheter tip near the dome to ensure safe coil deployment.

Efficacy of a 14-coil for Framing in Coil Embolization of Small Cerebral Aneurysms

Objective

The purpose of this study was to demonstrate the efficacy of a 14-coil (Target XL) for framing in coil embolization of small cerebral aneurysms.

Methods

Between January 2017 and December 2018, 46 patients underwent coil embolization of a small cerebral aneurysm that was less than 5 mm in maximum diameter. They were categorized into 26 patients in whom only 10-coils were used and 20 in whom Target XL was used for framing. The volume embolization rate (VER) and recanalization rate were compared between the two groups.

Results

Although there were two patients in whom Target XL was replaced with a 10-coil for framing, no adverse events associated with the use of Target XL were noted. The mean VER of the first framing coil was significantly higher in aneurysms that were framed with Target XL than in those framed with a 10-coil (Target XL 22.6 ± 4.5%, 10-coil 17.9 ± 8.4%; p = 0.03). Furthermore, the mean VER at the end of the procedure was significantly higher in aneurysms with Target XL used for framing than in those embolized using only 10-coils (14-coil: 36.8 ± 7.8%, 10-coil: 32.0 ± 6.5%; p = 0.03). No recanalization was observed in aneurysms for which Target XL was used for framing, whereas five aneurysms embolized using only 10-coils were recanalized.

Conclusion

Target XL may be safe and feasible as a framing coil in coil embolization of small cerebral aneurysms, which may result in a high VER, low recanalization rate, and good outcome.

Three-dimensional visualization of aneurysm wall calcification by cerebral angiography: Technical case report

BACKGROUND

We describe on a 57-year-old man with an incidental middle cerebral artery (MCA) aneurysm in whom a preoperative standard three-dimensional rotational angiogram (3D-RA) was used to depict luminal morphology along with 3D density rendering to precisely locate aneurysm wall calcification.

METHODS

To detect aneurysm calcification, a native 3D rotational angiogram was acquired for calcium density visualization, followed by an intraarterial contrast-enhanced 3D rotational angiogram in the same location. Both data sets were postprocessed obtaining a 3D calcium volume rendering on a 3D-RA.

RESULTS

Depiction of both the MCA luminal aneurysm morphology as well as calcium-rich components in the aneurysm wall was valuable to determine treatment strategy towards surgery.

CONCLUSION

Imaging of luminal morphology and calcification within the same angiographic procedure allows for a plain and simple estimation of the degree and distribution of brain aneurysm wall calcification with limited amount of additional radiation dosage.