Multidetector Computed Tomographic Angiography Of Cerebral Vessels In The Evaluation Of Suspected Non-Traumatic Subarachnoid Haemorrhage-Hospital Based Observational Study

Abstract

Subarachnoid hemorrhage is a serious neurological condition. About 85% of non-traumatic SAH are secondary to intracranial aneurysms rupture. It is associated with higher mortality of approximately 50 % overall and high survivor morbidity. Early detection and prompt treatment are necessary to reduce the disability. CT brain is the preliminary investigation to confirm the presence of SAH in clinically suspected cases. Digital Subtraction Angiography (DSA) is considered the gold standard investigation for evaluating the exact source of bleeding and site of intracranial aneurysms. However, the invasiveness of the procedure and associated risk of permanent neurological complications is a necessity for alternate less invasive investigations. Computed Tomographic Angiography (CTA) is a non-invasive and relatively less expensive procedure that can be performed in short time duration. Thus, it can be used as a primary imaging tool for evaluation of cerebral vascular diseases including aneurysms. The advantage also being, the study can be done as continuity of the initial brain CT for immediate diagnosis. Objectives of the study: 1. To detect and characterize the intracranial aneurysms in patients with non-traumatic subarachnoid hemorrhage by computed tomographic angiography of cerebral vessels. 2. To determine the association between size, location and multiplicity of aneurysm and their effect on aneurysm rupture MATERIALS AND METHODS This is a prospective observational study carried out on 45 patients who underwent computed tomographic angiography of the cerebral vessels over a period of 1 year duration at KLE’s Dr. Prabhakar Kore Hospital & MRC, Belagavi. There were 20 males and 25 males, their ages ranged from 14 to 78 years with mean age of 54.8 years. CTA were interpreted to assess the presence of aneurysms and their morphological characteristics. The findings were analyzed to find the association between aneurysm size and location with their rupture risk. RESULTS Total of 38 aneurysms were detected in 33 of the 45 patients of which 5 patients had 2 aneurysms each and rest had solitary aneurysm. In 12 of the 45 patients no aneurysm or other identifiable causes of SAH were identified. MDCT excellently delineated the number, size, location and multiplicity of aneurysms. Of the 38 aneurysms, 31 were in the anterior circulation and 7 in the posterior circulation. Among the 31 aneurysms seen at the anterior circulation, there were 11 at anterior communicating artery, 8 at internal carotid arteries, 6 each at anterior cerebral and middle cerebral arteries. Among the 7 aneurysms seen at the posterior circulation there were one each at top of the basilar artery, basilar & posterior cerebral arteries and 2 each at the posterior inferior cerebellar & vertebral artery. Of the 38 ruptured aneurysms there were 2 (5%) giant aneurysms, 1(2%) large aneurysm, 19(50%) medium aneurysms, 10(26%) small aneurysms and 6(15%) very small aneurysms. The smallest aneurysm identified by MDCTA was 2.2 mm, and the largest was 27 mm (mean size of 6.31 mm). The N/D ratios of the aneurysms were calculated in 36 aneurysms and there were 6 aneurysms with narrow neck and 30 aneurysms with wide neck. INTERPRETATION AND CONCLUSION • This study showed MDCTA to be a highly useful investigation in the evaluation of patients with spontaneous non traumatic subarachnoid hemorrhage. • Need for minimal patient co-operation, noninvasiveness of the procedure, quick scan duration and wide availability of the CT scanners make it the most suitable investigation in the acute setting of SAH. • Majority of the ruptured aneurysms in our study were of small to medium size (<12 mm). The most common site for aneurysm rupture was anterior communicating artery. Hence, small aneurysms should not be considered safe and have to be considered for treatment specially when they are located at vulnerable sites like ACOM. • The study also showed that size and location of aneurysm play an important role in their rupture risk and thus provide useful guide in the management of patients with aneurysmal SAH