Long-term retreatment rates of cerebral aneurysms in a population-level cohort

Influence of size ratio on retreatment after coil embolization for unruptured bifurcation aneurysms

Background

Aneurysm size is considered a risk factor for aneurysm rupture, and even small aneurysms may rupture, especially bifurcation aneurysms (BAs), which are occasionally detected. Therefore, we aimed to investigate the predictors of retreatment after coil embolization for unruptured BAs, with a particular focus on the absolute and relative size of the aneurysm (size ratio [SR]).

Methods

To evaluate the predictors of retreatment, patients were divided into two groups: those with and those without retreatment. Patient characteristics and radiographic assessments were compared between the groups. SR was defined as the ratio of the maximum aneurysm diameter and the average diameter of the parent artery.

Results

Overall, 181 unruptured BAs in 176 patients were investigated. The mean age of the patients was 63.8 ± 9.6 years. The mean aneurysm size and SR were 7.18 ± 2.94 mm and 2.49 ± 1.32, respectively. Further, 12 aneurysms with retreatment (6.6 %) and 169 aneurysms without retreatment were compared. In univariate analysis, SR was significantly higher in the group with retreatment (P = 0.02), but aneurysm size was not significantly different between the groups (P = 0.09). Multivariable analysis revealed that SR > 2.6 was a significant predictor of retreatment (P = 0.03; odds ratio: 10.41; 95 % confidence interval: 2.1-51.73).

Conclusions

This study showed that SR influences retreatment after coil embolization for unruptured BAs. Therefore, if the aneurysm size and parent artery diameter were small, as in cases with a large SR, meticulous follow-up after coil embolization is required to detect recurrence and recanalization.

European Stroke Organisation (ESO) guidelines on management of unruptured intracranial aneurysms

Unruptured intracranial aneurysms (UIA) occur in around 3% of the population. Important management questions concern if and how to perform preventive UIA occlusion; if, how and when to perform follow up imaging and non-interventional means to reduce the risk of rupture. Using the Standard Operational Procedure of ESO we prepared guidelines according to GRADE methodology. Since no completed randomised trials exist, we used interim analyses of trials, and meta-analyses of observational and case-control studies to provide recommendations to guide UIA management. All recommendations were based on very low evidence. We suggest preventive occlusion if the estimated 5-year rupture risk exceeds the risk of preventive treatment. In general, we cannot recommend endovascular over microsurgical treatment, but suggest flow diverting stents as option only when there are no other low-risk options for UIA repair. To detect UIA recurrence we suggest radiological follow up after occlusion. In patients who are initially observed, we suggest radiological monitoring to detect future UIA growth, smoking cessation, treatment of hypertension, but not treatment with statins or acetylsalicylic acid with the indication to reduce the risk of aneurysm rupture. Additionally, we formulated 15 expert-consensus statements. All experts suggest to assess UIA patients within a multidisciplinary setting (neurosurgery, neuroradiology and neurology) at centres consulting >100 UIA patients per year, to use a shared decision-making process based on the team recommendation and patient preferences, and to repair UIA only in centres performing the proposed treatment in >30 patients with (ruptured or unruptured) aneurysms per year per neurosurgeon or neurointerventionalist. These UIA guidelines provide contemporary recommendations and consensus statement on important aspects of UIA management until more robust data come available.

Surveillance of Unruptured Intracranial Aneurysms: Cost-Effectiveness Analysis for 3 Countries

BACKGROUND AND OBJECTIVES

No consensus exists on adequate surveillance of conservatively managed unruptured intracranial aneurysms (UIAs). We aimed to determine optimal MRI surveillance strategies for the growth of UIAs using cost-effectiveness analysis. A secondary aim was to develop a clinical tool for personalizing UIA surveillance.

METHODS

We designed a microsimulation model from a health care perspective simulating 100,000 55-year-old women to estimate costs and quality-adjusted life years (QALYs) over a lifetime horizon in the United States, the United Kingdom, and the Netherlands, using literature-derived model parameters. Country-specific costs and willingness-to-pay thresholds ($100,000/QALY for the United States, £30,000/QALY for the United Kingdom, and €80,000/QALY for the Netherlands) were used. Lifetime costs and QALYs were annually discounted at 3% for the United States, 3.5% for the United Kingdom, or 4% (costs) and 1.5% (QALYs) for the Netherlands. Strategies were no follow-up surveillance, follow-up with MRI in the first and fifth year after UIA discovery, every 5 years, every 2 years, or annually, or immediate intervention (i.e., clipping or coiling). Using the microsimulation model, we developed a tool for personalizing UIA surveillance for men and women, with different ages and varying aneurysm characteristics. Uncertainty in the input parameters was modeled with probabilistic sensitivity analysis.

RESULTS

Among 55-year-old women, 2,222 individuals in the United States, 1,910 in the United Kingdom, and 2,040 in the Netherlands needed to undergo an annual MRI scan to prevent 1 case of subarachnoid hemorrhage per year. No surveillance MRI was most cost-effective in the United States (in 47% of the simulations) and United Kingdom (in 54% of simulations), whereas annual MRI was most cost-effective in the Netherlands (in 53% of simulations). In the United States and United Kingdom, annual surveillance or surveillance in the first and fifth year after discovery was cost-effective in patients <60 years and at increased risk of aneurysm growth. The optimal, personalized, surveillance strategies were summarized in a look-up table for use in clinical practice.

DISCUSSION

Generally, the US and UK physicians should refrain from assigning patients, particularly older patients and those with few risk factors for aneurysm growth or rupture, to frequent MRI surveillance. In the Netherlands, annual follow-up is generally most cost-effective.

Case series of 100 supraorbital mini-craniotomies in patients with good grade aneurysmal subarachnoid haemorrhage at a single neurosurgical Centre

BACKGROUND

Endovascular techniques are becoming more common for cerebral aneurysms, but not all patients are suitable and open surgery is necessary for some. The traditional pterional approach requires a large craniotomy and this carries some morbidity in itself. With the growing expectation for minimally invasive surgery, we present our experience in supraorbital mini-craniotomy for good grade aneurysmal subarachnoid haemorrhage.

METHODS

Data on good-grade subarachnoid haemorrhage patients having aneurysms clipped via this approach were collected prospectively. Aneurysms at all anterior circulation sites were included, with the exception of the pericallosal artery, which was not within reach. A long-term follow-up questionnaire was sent to patients who had a supraorbital approach to clip the aneurysm at more than 1 year from hospital discharge.

RESULTS

Our results demonstrate mortality of 1% and severe residual disability in 10% of patients. Approach-related complications were low and it was considered that the operating space was not restricted in any of our cases. Return to work was achieved in 70% of patients who were working at the time of their haemorrhage.

CONCLUSIONS

Supraorbital micro-craniotomy is a safe approach for patients with proximal anterior circulation aneurysms, with low mortality and morbidity.

Retreatment of previously treated intracranial aneurysm: Procedural complications and risk factors for complications

OBJECTIVE

Intracranial aneurysm (IA) is a frequent vascular malformation that can be managed by endovascular treatment (EVT) or microsurgery. A previously treated IA can recanalize, which may require further treatment. The aim of our study was to evaluate procedural complications related to IA retreatment and their risk factors.

METHODS

All patients retreated for IA between 2007 and 2017 in 4 hospitals were included. We retrospectively reviewed the frequency of procedural complications of IA retreatment, defined as death or≥1-point increase in modified Rankin score 24h after the procedure. We then screened for risk factors of procedural complications by comparing the characteristics of patients with and without complications.

RESULTS

During the inclusion period, 4,997 IAs were treated in our 4 institutions. Of these, 237 (4.7%) were retreated. 29 (12.2%) had≥1 procedural complication. However, severe complications, defined as death or dependency at 1 month, occurred only in 3 patients (1.3%). The only risk factor for complications was microsurgical clipping as retreatment.

CONCLUSIONS

Procedural complications during IA retreatment were frequent but, in most cases, retreatment did not lead to death or severe disability. The only risk factor for complications of IA retreatment was clipping as retreatment. However, the design of the study did not allow any conclusion to be drawn as to the optimal means of aneurysm retreatment, and further studies are needed.

Cost-effectiveness analysis in patients with an unruptured cerebral aneurysm treated with observation or surgery

OBJECTIVE

The main goal of preventive treatment of unruptured intracranial aneurysms (UIAs) is to avoid the morbidity and mortality associated with aneurysmal subarachnoid hemorrhage. A comparison between the conservative approach and the surgical approach combining endovascular treatment and microsurgical clipping is currently lacking. This study aimed to conduct an updated evaluation of cost-effectiveness comparing the two approaches in patients with UIA.

METHODS

A decision tree with a Markov model was developed. Quality-adjusted life-years (QALYs) associated with living with UIA before and after treatment were prospectively collected from a cohort of patients with UIA at a tertiary center. Other inputs were obtained from published literature. Using Monte Carlo simulation for patients aged 55, 65, and 75 years, the authors modeled the conservative management in comparison with preventive treatment. Different proportions of endovascular and microsurgical treatment were modeled to reflect existing practice variations between treatment centers. Outcomes were assessed in terms of QALYs. Sensitivity analyses to assess the model's robustness and completed threshold analyses to examine the influence of input parameters were performed.

RESULTS

Preventive treatment of UIAs consistently led to higher utility. Models using a higher proportion of endovascular therapy were more cost-effective. Models with older cohorts were less cost-effective than those with younger cohorts. Treatment was cost-effective (willingness to pay < 100,000 USD/QALY) if the annual rupture risk exceeded a threshold between 0.8% and 1.9% in various models based on the proportion of endovascular treatment and cohort age. A higher proportion of endovascular treatments and younger age lowered this threshold, making the treatment of aneurysms with a lower risk of rupture more cost-effective.

CONCLUSIONS

Preventive treatment of aneurysms led to higher utility compared with conservative management. Models with a higher proportion of endovascular treatment and younger patient age were most cost-effective.

Management of Aneurysmal Subarachnoid Hemorrhage: Variation in Clinical Practice and Unmet Need for Follow-up among Survivors-A Single-Center Perspective

OBJECTIVE

The purpose of the present study is to investigate the existence and/or prevalence of clinical practice variation in management of aneurysmal subarachnoid hemorrhage (aSAH) and to determine the need for long-term follow-up.

METHODS

A single-center study was carried out of patients with aSAH over a 5-year period divided into 2 halves (2.5 years each) before and after addition of a dually trained cerebrovascular neurosurgeon. In-hospital clinical practice, clinical outcome (mortality and discharge destination) and long-term outcome (modified Rankin Scale score and Telephone Interview for Cognitive Status [TICS]) were compared using descriptive summaries and nonparametric tests.

RESULTS

Among 251 patients admitted with aSAH, 115 (45.8%) were before the index event, whereas 136 (54.2%) were during the later period. The aneurysm-securing procedure changed from coil embolization to clip ligation (12/115 [10.4%] vs. 84/136 [61.8%]; P < 0.0001) during the latter years. Interventional treatment for cerebral vasospasm has decreased (58/115 [50.4%] vs. 49/136 [36.0%]; P = 0.0002). Patients surviving hospitalization had more clinic follow-up after discharge during the latter period (42/85 [49.4%] vs. 76/105 [72.4%]; P = 0.0012) and ventriculoperitoneal shunt placement for delayed hydrocephalus (1/85 [1.2%] vs. 9/105 [8.6%]; P = 0.02). A subcohort of aSAH survivors (n = 46) had lower median TICS score during the earlier study period (31.5 [interquartile range, 22-36] vs. 33 [interquartile range, 27-38]; P = 0.038). Similarly, preictal smoking status and hyperlipidemia were associated with adverse TICS score in a multivariate model (P = 0.007).

CONCLUSIONS

Postdischarge clinical follow-up has improved facilitating recognition and treatment of delayed hydrocephalus. Existence of cognitive deficits among survivors calls for establishment of multidisciplinary clinics for long-term management of aSAH.