An Analysis of Intracranial Aneurysms Presenting with Subarachnoid Haemorrhage in Manipal Teaching Hospital Pokhara

Introduction: Rupture of intracranial aneurysms is the most common cause for spontaneous subarachnoid hemorrhage. It is a devastating stroke with high morbidity and mortality. This study was done to determine the frequency, location and size of aneurysms in patients presenting with spontaneous subarachnoid hemorrhage. Methods: This prospective cross sectional observational study was conducted in the Neurosurgery Unit of Manipal Teaching Hospital from January 2012 to June 2016. All patients who presented with spontaneous subarachnoid hemorrhage and had a positive angiography of brain were included in the study. Results: There were 39 patients who had positive angiographic results. Male: female ratio was 1:2.25. Mean age was 55.79 years. Nine patients had more than one aneurysms. More than 50% of patients were of age group 50-70 years. Anterior circulation aneurysms were found in 90% of patients. Anterior communicating artery was the commonest location of aneurysms. Most of the aneurysms had neck size less than 4 mm. Conclusion: Anterior communicating artery aneurysm was the commonest location of ruptured aneurysms. 23.07% of patients had multiple aneurysms.


INTRODUCTION
Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space -the area between the arachnoid membrane and the pia mater surrounding the brain. 1 Most common cause of subarachnoid hemorrhage is trauma.Non traumatic or spontaneous subarachnoid hemorrhage is due to rupture of aneurysms, arteriovenous malformations and other Licensed under CC BY 4.0 International License which permits use, distribution and reproduction in any medium, provided the original work is properly cited vascular anomalies.Classical presentation of ruptured aneurysm causing subarachnoid hemorrhage is thunderclap headache (a headache described as "like being kicked on the head" or the "worst headache ever' developing over seconds to minutes). 2owever patients may have nausea, vomiting, seizures, neck pain, photophobia and focal cranial or motor deficit or may even present with coma.Clinical condition of patients with subarachnoid hemorrhage is classified according to Hunt and Hess grading 3 and WFNS grading. 4Aneurysms may be detected incidentally as well.Rapid expansion of an aneurysm like posterior communicating artery aneurysm may present with third nerve palsy.Giant aneurysms with in situ thrombus may present with cerebral infarction due to thromboembolism.
Non contrast computed tomography is the investigation of choice for confirming the presence of subarachnoid hemorrhage.It detects subarachnoid hemorrhage in 98.7% patients within six hours of ictus. 5Lumbar puncture is mandatory if CT is negative but still clinical suspicion of subarachnoid hemorrhage is high.CSF studies show evidence of hemorrhage in 3% of people in whom CT is found normal. 6Fischer grade classifies the appearance of subarachnoid hemorrhage on CT scan. 7It has prognosis for development of cerebral vasospasm , one of the dreadful complications.After subarachnoid hemorrhage is confirmed, its source should be determined by doing CT angiography or digital subtraction angiography.This study was conducted to find out the frequency, location and size of aneurysms in patients presenting with spontaneous subarachnoid hemorrhage.The rationale was to find out the distribution of ruptured intracranial aneurysms in patients from this western part of Nepal.

This observational cross sectional study was carried out in Manipal Teaching
Hospital Pokhara Nepal from January 2012 to June 2016.Patient population included patients who presented with subarachnoid hemorrhage.All patients with subarachnoid hemorrhage underwent CT angiography of brain on 16 slice multidetector CT scanner.Scan was taken from base of skull to vertex.In addition to axial source data, post processed multiplanar reformatted (MPR), maximum intensity projection (MIP) and 3 D volume rendering (VR) images were evaluated for any aneurysms.Aneurysms morphology studied include location of aneurysm, number of aneurysm, neck size and length and breathe of the fundus.Only patients who had an aneurysm demonstrated on the CT angiography were taken for analysis.

RESULTS
There were 39 patients who had positive angiographic results.There were 12 males (30.77%) and 27 females (69.23%).Female: male ratio was 2.25:1.These patients harbored 50 aneurysms.Mean age was 55.79 years and ranged from 18 to 78 years.Age distribution of patients is given in Table 1.Thirty patients (76.92%) had single aneurysm, 7 patients (17.95%) had two aneurysms and two patients (5.13%) had three aneurysms.Forty five aneurysms (90%) were in the anterior circulation and five aneurysms (10%) were in the posterior circulation.Anterior communicating artery aneurysm was the most common site for aneurysms followed by middle cerebral artery aneurysm.Table 2 shows the aneurysm locations.Among patients who had more than one aneurysm, 2 patients were male and 7 were females.Thus multiple aneurysms were found in 23.08% of patients.Multiple aneurysm were found in 16.7% of male and 25.94% of females.Mean neck size was 3.75+/-1.78mm and ranged from 1.3 to 10.3 mm.Thirty five aneurysms (70%) had neck size <4 mm, 14 aneurysms(28%) had neck size 4-10 mm and 1 aneurysm (2%) had neck size more than 10 mm.In a study done in Finland by Korja M et al 13 male: female ratio of 1993 patients with ruptured intracranial aneurysms was 1:1.5.Ninety percent of aneurysms were of the anterior circulation, 83% of all aneurysms of middle cerebral artery, anterior communicating artery, posterior communicating artery and pericallosal artery.Sixty eight percentage of aneurysms were <10 mm.Multiple aneurysms were found in 30% patients.Multiple aneurysms were found in 17.72 % of patients in a study done in Japan 14 ,among male multiple aneurysms were found in 12.4% and among females in 20.2%.

CONCLUSION
In the current study, as in other studies, anterior communicating artery was the commonest site of ruptured aneurysm causing spontaneous subarachnoid hemorrhage.Ruptured aneurysms were found more in females.More than 95% of aneurysms were small sized with neck diameter <10 mms.Multiple aneurysms were found in 23% of patients.