Chinese Small Intracranial Aneurysm Study (CSIAS)

Study Overview
=================
Brief Summary
-----------------
Intracranial aneurysms are common in the general population. The overall prevalence of unruptured intracranial aneurysms (UIAs) is estimated of 2.3-3.2% in the population without specific risk factors for SAH. As noninvasive imaging modalities are more commonly used than before, UIAs are increasingly being detected. Most patients with small aneurysms (less than 5mm) are incidentally found in clinical practice. Some studies indicate that the majority of patients with UIAs, particularly with small aneurysms (<7mm), have a low risk of rupture, and others have found that small ruptured aneurysms have a high proportion in patients with SAH. Therefore, there is a lot of controversy regarding which small aneurysms can be left untreated, or which aneurysms are needed to be treated with clipping or coiling. The prevalence varies widely among different detection methods, race/ethnicity or patients with other inherited diseases. Although a wealth of data is available for the natural history of UIAs, the true natural history remains unknown because case selection bias occur in almost all studies. However, data on Chinese UIA is unknown. Using the MR angiography (MRA) to detect aneurysms, the prevalence is 7% of selected adult population in China. Therefore, small UIAs are very common and are increasingly being detected in clinical practice. Conservative treatment, surgical clipping and endovascular coiling are the three treatment options for UIAs. The optimal treatment remains controversial, particularly for small aneurysms (less than 7mm). To date, no clinical trials have compared the safety and efficacy between conservative treatment and surgical clipping or endovascular coiling for UIAs. It may be impossible to conduct the randomized controlled study considering aneurysm ruptured as a devastating event. However, surgical clipping or endovascular treatment itself carries a risk of immediate morbidity or mortality. Therefore, a substantial variability widely exists in treatment decision-making for UIAs, and this may lead to a great variability in clinical recommendations. Our study is a prospective observational study to identify the incidence of rupture of small aneurysms in the first year after the diagnosis of the aneurysm which is left untreated. Meanwhile, we determine the differences of outcomes, procedural complications, and rates of retreatment between surgical clipping and endovascular coiling for small UIAs in China.

Detailed Description
-----------------
Background: There is a lot of controversy regarding which aneurysms can be left untreated, or which aneurysms are needed to be treated with clipping or coiling. To date, no clinical trials have compared the safety and efficacy between conservative treatment and surgical clipping or endovascular coiling for small UIAs. Study design: A multicenter prospective observation registry study. This study is undertaken to conform to the study protocol. Patients will be recruited between December 2016 and December 2018. Patients are eligible for the study if they meet the inclusion criteria and they are not eligible if any of the following exclusion criteria are met. Procedures: All patients were interviewed by a multidisciplinary team that consisted of vascular neurosurgeons, interventional neuroradiologists and anesthetists. If patients meet all of the inclusion criteria: an unruptured aneurysms ≤5mm are enrolled and then followed up at 6 and12 months. Clinical observation, surgical clipping and endovascular coiling are the three treatment options for UIAs. In general, when an UIA is detected, it should be needed to quit smoking, to aggressively manage hypertension, and to control alcohol use. When an aggressive treatment is considered, treatment risks should be balanced against the risk of rupture.

Official Title
-----------------
Treatment of Small Unruptured Intracranial Aneurysms Based on Clinical Characteristics, Morphology and Hemodynamic Features

Conditions
-----------------
Intracranial Aneurysm, Unruptured Cerebral Aneurysm, Treatment Side Effects

Intervention / Treatment
-----------------
* Procedure: Coiling or Clipping


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Intracranial unruptured aneurysms confirmed by digital subtraction angiography DSA, CT angiography or MR angiography (MRA); The maximum size of unruptured aneurysm ≤5mm; Informed consent Exclusion Criteria: 1.Patients with severe systemic disorders and expected life span less than one year; 2.Pregnant or lactating women.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Observation<br>Aneurysms are left untreated based on patients and family's wishes. These patients will be included in the observation group. | |
| Coiling or Clipping<br>Patients are included in the coiling group if they undergo endovascular coiling, such as single coiling, stent-assisted coiling and balloon-assisted coiling. Or Patients are included in the clipping group if they undergo surgical coiling, such as aneurysm neck clipping, aneurysm isolation or trapping. | Procedure: Coiling or Clipping<br>* All patients are treated under general anesthesia and systemic heparinization. A bolus of 50-75 IU/kg of heparin is given after femoral sheath placement, and intermittent boluses of 1250 IU per hour are given during the procedure. Activated clotting time is maintained at 2-3 times baseline level. Balloon-assisted coiling or stent-assisted coiling are considered in aneurysms with an unfavorable morphology (aneurysm neck≥ 4.0 mm or dome/neck ≤2.0). All anterior circulation aneurysms are clipped through a standard pterional or frontal temporal approach. The posterior circulation aneurysms are treated using far lateral approach depending on the aneurysm location.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rupture of an unruptured aneurysm | These aneurysms are left untreated. | One year of follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Regrowth of an unruptured aneurysm |  | 9 and 12 months of imaging follow-up | 
| Recurrence and retreatment after coiling or clipping |  | one year of follow-up | 
| Poor outcome after coiling or clipping | Poor outcome is defined as a mRS 3-6 | 6 and 12 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Unruptured Intracranial Aneurysm, Small aneurysms, Risk of rupture, Natural history, Endovascular Coiling, Surgical clipping