Patients data
This study was approved by the hospitals ethical review board and institutional review board. Consent forms for all patients were obtained and in the case of a minor a guardian was asked to sign on their behalf. All patients with ruptured and unruptured intracranial aneurysms initially treated with endovascular coiling with or without remodeling technique between July, 2015 to August 2018 are included in this study. The information was obtained from a neurointerventional procedure log book maintained at the institute. The time period chosen allows an opportunity for retrospection of atleast 3 years of clinical and angiographic follow ups. Prior clipping was set as an exclusion criterion in the study. If multiple aneurysms were present, the ruptured aneurysm was determined from the distribution of subarachnoid hemorrhage and intraventricular blood. If the site of the hemorrhage could not identify the ruptured aneurysm, we treated all aneurysms in single session. Patients age, sex, the presence or absence of smoking and hypertension, number of aneurysms, whether or not it ruptured, the location of aneurysm and any recurrences were recorded. The recovery of patients was gauged clinically with the Modified Rankin scale and radiological outcome was measured through Raymond classification and both were also recorded for analysis.
Acute Management Paradigm:
During the time period of this study, the overall management strategy was endovascular coiling as the first treatment option, if feasible. Each case was discussed and consensus reached by members of neurointerventional team. Patients with large intracerebral hemorrhage associated with a ruptured aneurysm generally underwent emergency evacuation prior to coiling. Ruptured intracranial aneurysms were generally treated within 24 to 72 hours of rupture. In all endovascular treated aneurysms detachable coils were used with the goal of occluding as much as of aneurysm as possible in a safe manner. In case of aneurysms with wide necks or unfavorable shapes, we used assisted technique of double catheter, balloon or stent assisted coiling. After the completion of coil embolization, we divided the angiographic findings into three classes using the Modified Raymond Scale: complete occlusion, neck remnant and residual aneurysm.
Clinical Parameters and Long Term Follow Up:
Baseline clinical information was retrospectively abstracted from hospital charts and stratified. Computed tomography scans and digital subtraction angiograms were analyzed prior to deploying the first coil. Aneurysm sac diameter, neck width and dome to neck ratio was analyzed before prior coiling. The use of remodeling techniques (balloon or stent) were also decided on angiography. Clinical outcome was defined as a deterioration of >0 on the mRS and any deaths related to the treatment. Clinical outcome and neurological status were evaluated in detail during every outpatient visit as well as via follow-up over call.
Angiographic Analysis and Long Term Follow Up:
Angiographic follow up is not routinely done for clipped aneurysms, however, coiled aneurysms need follow up, but the recommendable length of follow up has not been established. Age of the patient, comorbidities, size and shape of the aneurysm, location, rupture status and occlusion grade were taken into account when deciding the follow up duration by Sprengers et.al (2008) (3) who suggested that adequately occluded aneurysms at six months after coiling do not need imaging follow up, except aneurysms that are partially thrombosed or larger than 15 mm. The standard operating procedure at our institution is having first follow up angiography (MRA) after 6 months, followed by another at 1 year and then serially for 3 years. In patients with incomplete initial aneurysm occlusion or reopening of the aneurysm over time, different intervals for angiographic follow up were chosen because additional treatment was considered in those patients. In other cases, if post coiling six months MRA showed some residual or recurrent neck, we have a fixed protocol that entails repeating the angiogram to confirm the findings of MRA.
Outcome Measures:
The outcome was assessed by an independent neurosurgeon and neurointerventionalist by using the modified Rankin Scale. The primary outcome measure was functional outcome at discharge and at first follow up after 15 days and then every 6 months until the end of 3-year period.
Methodology of Analysis:
IBM SPSS Version 25 was used for the analysis of data-set collected. A specialist statistician’s services were acquired for the tabulation of data, the decision of analysis to be conducted and for the interpretation and analysis of data findings. Multi-variate auto-regressions were run keeping all factors in a single equation. Beta values of 1 and 0 were assigned to people with smoking and hypertension present or absent. Furthermore, smoking, hypertension, age group and sex were all individually tested against clinical outcomes. As well as conducting a chi-square test to the see the results of various permutations such as age and hypertension, age and smoking, sex and age etc. Cronbach-Alpha, p and p2 values were also determined to ratify the statistical significance of results. A linear regression equations was made and run to find the impact of factors on clinical outcomes and the equations can be seen as follows:
Clinical Outcome= Age + Sex + Hypertension + Smoking + Residual
Clinical outcomes were on the Modified Rankin Scale with rating from 0-6. 0 being perfect recovery and 6 being death. Age was divided into intervals of 10 years as follows <20 21-30 30-40 40-50 50<. Finally, sex, hypertension and smoking were kept as binary variables with sex being male or female and hypertension and smoking being present or absent. The entire raw-data set can be found in (Table 1) and is available online for cross checking and further analysis.