Surgical and Endovascular Comprehensive Treatment Outcomes of Unruptured Intracranial Aneurysms: Reduction of Treatment Bias

Microsurgical clipping of unruptured intracranial aneurysms: Clinical and radiological outcomes

BACKGROUND AND OBJECTIVES

The prevalence of unruptured intracranial aneurysms is 1-3%. The annual rupture rate increases in patients with multiple aneurysms that presented a previous hemorrhage from another aneurysm.

OBJECTIVES

To evaluate outcomes of clipping unruptured aneurysms, comparing patients with single or multiple aneurysms clipped, describe the complications related to surgery and to identify risk factors predicting an unfavorable outcome.

MATERIALS AND METHODS

Retrospective study including patients who underwent clipping of unruptured aneurysms between 2020-2023 at our center. Occlusion rate, complications, and functional outcome were analyzed. Risk factors for poor prognosis are identified using univariate model.

RESULTS

82 patients with 114 aneurysms were treated with microsurgery. Multiple aneurysms were clipped in 22 patients. A mini-open approach was used in 86,5% of cases. Complete occlusion in angio3D was found in 78.6% of clipped aneurysms. Complication rate was 12.2%, including asymptomatic cases. Mortality was 0%. The probability of 1 point mRS worsening was 7.3% and 2 or more points was 1.2%, with a good functional outcome in 98.9%. Clipping multiple aneurysms, miniopen approaches, or surgery in patients with previous subarachnoid hemorrhage did not increase the risk of complications. Posterior circulation aneurysms surgery increased the risk of ischemia.

CONCLUSIONS

The management for unruptured intracranial aneurysms should be multimodal and based on clinical and radiological outcomes. Microsurgery is a valid and safe technique, with 0% mortality and bleeding rates and 1,2% rate of severe morbidity in our series.

Trends in the Age of Patients Treated for Unruptured Intracranial Aneurysms from 1990 to 2020

BACKGROUND

The decision for treatment for unruptured intracranial aneurysms (UIAs) is often difficult. Innovation in endovascular devices have improved the benefit-to-risk profile especially for elderly patients; however, the treatment guidelines from the past decade often recommend conservative management. It is unknown how these changes have affected the overall age of the patients selected for treatment. Herein, we aimed to study potential changes in the average age of the patients that are being treated over time.

METHODS

A systematic search of the literature was performed to identify all studies describing the age of the UIAs that were treated by any modality. Scatter diagrams with trend lines were used to plot the age of the patients treated over time and assess the presence of a potential significant trend via statistical correlation tests.

RESULTS

A total of 280 studies including 83,437 UIAs treated between 1987 and 2021 met all eligibility criteria and were entered in the analysis. Mean age of the patients was 55.5 years, and 70.7% were female. There was a significant increasing trend in the age of the treated patients over time (Spearman r: 0.250; P < 0.001), with a 1-year increase in the average age of the treated patients every 5 years since 1987.

CONCLUSIONS

The present study indicates that based on the treated UIA patient data published in the literature, older UIAs are being treated over time. This trend is likely driven by safer treatments while suggesting that re-evaluation of certain UIA treatment decision scores may be of great interest.

The impact of initial counselling for patients' decision-making and the accuracy of interdisciplinary neurovascular board evaluation in elective treatment of unruptured intracranial aneurysms - a German single-centre retrospective study

OBJECTIVE

Interdisciplinary-neurovascular-boards (INVB) are deemed to find the patient's optimum treatment-modality in elective unruptured intracranial aneurysm-repair (EUIAR). If INVB judges risk/success estimation similar for microsurgical/endovascular EUIAR, the choice for either modality is up to the informed patient. However, it is unknown if the patients' decision-making might be biased by the discipline of initial counselling prior to INVB and if INVB's equal risk/success estimation is finally accurate.

METHODS

We analysed all our patients with EUIAR after INVB-discussion between 2007 and 2017 and identified those patients where INVB-recommendation estimated similar risk/success rates for both treatment-modalities. We investigated the procedural/outcome parameters and determined if the mode of initial counselling prior to INVB influenced the patients' choice of EUIAR and if INVB's equal risk/success estimation was accurate.

RESULTS

Within altogether 572 patients with EUIAR during our study period, we identified 99 patients (agemean:58 yrs; m:f=1:2) in whom pre-treatment INVB-discussion estimated risk/success rates for both modalities of EUIAR to be similar. Prior to INVB-discussion, 80 of the 99 patients had been initially counselled in the neurosurgical discipline and 19 patients in the endovascular discipline. The final patients' decision rates for surgical vs. endovascular EUIAR (after secondary consultation of each patient in both disciplines after INVB-discussion) were 67% vs. 33% in the first and 58% vs. 42% in the latter group (no significant difference: p = 0.345). Uni- and multivariate analysis did not show any hints for a bias in patients' decision-making caused by the discipline of initial counselling prior to INVB/secondary bilateral consultations. Clinical and procedural outcome at last follow-up (median:18mos) did not differ between those 66 patients that eventually decided for microsurgical and those 33 patients that eventually decided for endovascular EUIAR, underlining the high accuracy of INVB's pre-treatment risk/success estimations.

CONCLUSION

Only in a small number of patients, INVB estimates both disciplines to be of equal value for EUIAR which proves to be highly accurate at long-term outcome measures. Initial contact to one or the other neurovascular discipline does not appear to play a significant role in the final patient's decision-making process.

Microsurgery for intracranial aneurysms: A qualitative survey on technical challenges and technological solutions

Introduction

Microsurgery for the clipping of intracranial aneurysms remains a technically challenging and high-risk area of neurosurgery. We aimed to describe the technical challenges of aneurysm surgery, and the scope for technological innovations to overcome these barriers from the perspective of practising neurovascular surgeons.

Materials and Methods

Consultant neurovascular surgeons and members of the British Neurovascular Group (BNVG) were electronically invited to participate in an online survey regarding surgery for both ruptured and unruptured aneurysms. The free text survey asked three questions: what do they consider to be the principal technical barriers to aneurysm clipping? What technological advances have previously contributed to improving the safety and efficacy of aneurysm clipping? What technological advances do they anticipate improving the safety and efficacy of aneurysm clipping in the future? A qualitative synthesis of responses was performed using multi-rater emergent thematic analysis.

Results

The most significant reported historical advances in aneurysm surgery fell into five themes: (1) optimising clip placement, (2) minimising brain retraction, (3) tissue handling, (4) visualisation and orientation, and (5) management of intraoperative rupture. The most frequently reported innovation by far was indocyanine green angiography (84% of respondents). The three most commonly cited future advances were hybrid surgical and endovascular techniques, advances in intraoperative imaging, and patient-specific simulation and planning.

Conclusions

While some surgeons perceive that the rate of innovation in aneurysm clipping has been dwarfed in recent years by endovascular techniques, surgeons surveyed highlighted a broad range of future technologies that have the potential to continue to improve the safety of aneurysm surgery in the future.

Avenir® vs. AxiumTM Coils for the Treatment of Intracranial Aneurysms: Results of a Multicenter Randomized Controlled Trial With Short-Term Follow-Up

Purpose

Endovascular coil occlusion is a successful and rapidly evolving strategy used to treat patients who present with intracranial aneurysms. This study aimed to compare the safety and efficacy of the Avenir® and Axium^TM passive mechanically detachable coil systems.

Methods

A prospective, multicenter, randomized controlled study was carried out at ten medical centers from March 2018 to December 2019. A series of consecutive patients diagnosed with intracranial aneurysms were randomly assigned to undergo endovascular treatment with either the Avenir® or the Axium^TM mechanically detachable coil systems. The short-term outcomes from the two groups were compared with a focus on treatment efficacy and safety.

Results

A total of 162 and 161 patients were enrolled in the Avenir and Axium groups, respectively. The rate of successful coil detachment was 100% for the Avenir group and 99.38% for the Axium group. At the six-month follow-up visit, the overall aneurysm occlusion rate was 94.66% for the Avenir group and 96.95% for the Axium group (p > 0.05). We observed no statistically significant differences in clinical condition (as per the modified Rankin Scale) or the degree of aneurysm occlusion (as determined by digital subtraction angiography [DSA] and Raymond-Roy Occlusion Classification). Surgical complications were reported in 27 subjects in the Avenir group and 22 in the Axium group (p > 0.05). DSA performed at 6 months revealed complete aneurysm occlusion in 84 and 86% of patients in the Avenir and Axium groups, respectively.

Conclusion

We observed no significant short-term differences with respect to efficacy or safety when using either Avenir® or Axium^TM coils for the treatment of intracranial aneurysms.

Adverse intraoperative events during surgical repair of ruptured cerebral aneurysms: a systematic review

Compared with endovascular techniques, clipping of ruptured cerebral aneurysms has been shown to associate with increased morbidity in several studies. Despite this, clipping remains the preferred option for many aneurysms. The objective of this study is to describe the reported adverse events of open repair of ruptured cerebral aneurysms and their impact on patient outcome. The PubMed, Embase and Cochrane databases were searched between June 1999 and June 2019 to identify original studies of at least 100 patients undergoing surgical repair of ruptured cerebral aneurysms and in which adverse event rates were reported. Thirty-six studies reporting adverse events in a total of 12,410 operations for repair of ruptured cerebral aneurysms were included. Surgical adverse events were common with 36 event types reported including intraoperative rupture (median rate of 16.6%), arterial injury (median rate of 3.8%) and brain swelling (median rate 5.6%). Only 6 surgical events were statistically shown to associate with poor outcomes by any author and for intraoperative rupture (the most frequently analysed), there was an even split between authors finding a statistical association with poor outcome and those finding no association. Even with modern surgical techniques, the technical demands of surgical aneurysm repair continue to lead to a high rate of intraoperative adverse events. Despite this, it is not known which of these intraoperative events are the most important contributors to the poor outcomes often seen in these patients. More research directed towards identifying the events that most drive operative morbidity has the potential to improve outcomes for these patients.

Women With First-Hand Tobacco Smoke Exposure Have a Higher Likelihood of Having an Unruptured Intracranial Aneurysm Than Nonsmokers: A Nested Case-Control Study

BACKGROUND

The prevalence of unruptured intracranial aneurysms (UIA) in females who smoke cigarettes and the association between smoking and hypertension with purely incidental UIAs have been unexplored.

OBJECTIVE

To obtain the prevalence of UIA among females and to assess the relationship between smoking and hypertension with a diagnosis of incidental UIAs.

METHODS

A nested case-control study from a cohort of female patients aged between 30 and 60 yr with a brain magnetic resonance angiography (MRA) between 2016 and 2018. Incidental UIAs were compared to patients with normal MRAs. Smoking was characterized as never or former/current smokers. A logistic regression was used to evaluate the association between smoking, hypertension, or both, with a diagnosis of incidental UIAs.

RESULTS

A total of 1977 patients had a brain MRA between 2016 and 2018. From 1572 nonsmoker patients, we encountered 30 with an UIA (prevalence: 1.9%). There were 405 patients with a positive smoking history, and 77 patients harbored an UIA (prevalence: 19%). Of 64 aneurysm patients and 130 random controls eligible for the case control, aneurysm patients were more likely to have a positive smoking history and hypertension compared with healthy controls (60% vs 18%, P ≤ .001; 44% vs 14%, P ≤ .001). A multivariable analysis demonstrated a significant association between a smoking history, hypertension, or both factors with an incidental UIA (odds ratio [OR] 5.8 CI 1.22-11.70; OR 3.8 CI 2.31-14.78; OR 12.6 CI 4.38-36.26; respectively).

CONCLUSION

Females who smoke cigarettes have a higher prevalence of UIAs than the general population. Smoking confers a higher risk for having a silent UIA, aggravated by hypertension. This population is an ideal target for potential screening.

The FRED for Cerebral Aneurysms of the Posterior Circulation: A Subgroup Analysis of the EuFRED Registry

BACKGROUND AND PURPOSE

Flow diversion for the posterior circulation remains a promising treatment option for selected posterior circulation aneurysms. The Flow-Redirection Intraluminal Device (FRED) system has not been previously assessed in a large cohort of patients with posterior circulation aneurysms. The purpose of the present study was to assess safety and efficacy of FRED in this location.

MATERIALS AND METHODS

Consecutive patients with posterior circulation aneurysms treated at 8 centers participating in the European FRED study (EuFRED) between April 2012 and January 2019 were retrospectively reviewed. Complication and radiographic and functional outcomes were evaluated.

RESULTS

Eighty-four patients (median age, 54 years) with 84 posterior circulation aneurysms were treated with the FRED. A total of 25 aneurysms (29.8%) had previously ruptured, even though most aneurysms were diagnosed incidentally (45.2%). The intradural vertebral artery was the most common location (50%), and saccular, the most common morphology (40.5%). The median size was 7 mm. There were 8 (9.5%) symptomatic thromboembolic and no hemorrhagic complications. Thromboembolic complications occurred mostly (90.9%) in nonsaccular aneurysms. On last follow-up at a median of 24 months, 78.2% of aneurysms were completely occluded. Functional outcome at a median of 27 months was favorable in 94% of patients. All mortalities occurred in patients with acute subarachnoid hemorrhage and its sequelae.

CONCLUSIONS

The largest cohort of posterior circulation aneurysms treated with the FRED to date demonstrated favorable safety and efficacy profiles of the device for this indication. Treatment in the setting of acute subarachnoid hemorrhage was strongly related to mortality, regardless of whether procedural complications occurred.