Site Of Rupture In Patients Research Articles

Subarachnoid Hemorrhage

Intracranial aneurysms or arterial dissections are major causes of subarachnoid hemorrhage(SAH). Early surgical or endovascular repair of the bleeding source is crucial because rebleeding mostly occurs within a few days after the initial attack. Radiological examination is an initial step for the appropriate diagnosis of ruptured intracranial aneurysms and arterial dissections. However, misdiagnosis may occur, especially in patients with minor bleeding or multiple aneurysms. In addition to computed tomography, magnetic resonance imaging, including FLAIR and SWI, and T2*WI are useful for detecting minor SAH. Vessel-wall imaging has recently been applied to diagnosing the site of rupture in patients with multiple cerebral aneurysms or microaneurysms, but not to assessing the instability of unruptured cerebral aneurysms or intracranial arterial dissections. In this article, we discuss the current radiological modalities and their usefulness for diagnosing SAH.

Diagnostic value of non-enhanced computed tomography in identifying location of ruptured cerebral aneurysm in patients with aneurysmal subarachnoid haemorrhage.

In patients with SAH and multiple aneurysms, the ruptured lesion must be identified to prevent recurrent bleeding. To assess the diagnostic value of non-enhanced computed tomography (NECT) in identifying the rupture site in patients with subarachnoid haemorrhage (SAH) and multiple aneurysms. We included patients with SAH revealed by NECT and multiple aneurysms detected on computed tomography angiography (CTA) in whom a ruptured aneurysm was identified during neurosurgery. Two radiologists predicted the location of the ruptured aneurysm based on the distribution of the SAH and location of intracerebral haematoma (ICH) by NECT. Eighty-three patients with a mean age of 55.7 ± 14.4 years were included. Ruptured aneurysms were significantly larger (mean size 7.7 ± 4.7 mm) than unruptured aneurysms (mean size 5.9 ± 4.5 mm; p = 0.014). Interobserver agreement was 0.86 (p < 0.001). Overall sensitivity and specificity of radiological prediction were 78.3% (95% CI, 68.6%-87.1%) and 96.4% (95% CI, 94.3%-97.8%) respectively. Overall PPV and NPV were 78.3% (95% CI, 67.6%-86.3%) and 96.8% (95% CI, 94.8%-98.1%) respectively. The sensitivity and PPV for aneurysms in the anterior communicating, anterior, and middle cerebral arteries appeared to be significantly higher than in other locations (p = 0.015 and 0.019 respectively). Analysis of independent predictive factors of correct radiological location revealed that ICH predisposes to a correct radiological diagnosis with an odds ratio of 8.57 (95% CI, 1.07-68.99; p = 0.03). NECT has a high diagnostic value in identifying the source of bleeding in patients with multiple aneurysms for anterior circulation aneurysms, especially with coexisting ICH. For other locations, NECT is not reliable enough to base treatment decisions upon.

Circumferential Wall Enhancement on Magnetic Resonance Imaging is Useful to Identify Rupture Site in Patients with Multiple Cerebral Aneurysms.

Identification of rupture sites in patients with multiple intracranial aneurysms is largely based on aneurysm size, location, and shape. Finding circumferential enhancement along the aneurysm wall (CEAW) on magnetic resonance (MR) vessel wall imaging was recently shown to be indicative of ruptured aneurysm. To investigate the hypothesis that a higher degree of CEAW would identify the site of rupture in patients with multiple aneurysms. We prospectively performed quantitative analysis of CEAW in consecutive patients with both aneurysmal subarachnoid hemorrhage and multiple aneurysms (26 patients with a total of 62 aneurysms), using MR vessel wall imaging. Three-dimensional T1-weighted fast spin-echo sequences were obtained before and after injection of contrast media, and the wall enhancement index (WEI) was calculated. Aneurysm characteristics (size, location, irregular shape, aspect ratio [neck-to-dome length/neck width], and WEI) were compared between ruptured and unruptured aneurysms. Odds ratios with 95% confidence intervals for ruptures were calculated with conditional univariable logistic regression analysis. Analyses were repeated after adjustment for aneurysm size. Large aneurysm size, high aspect ratio, WEI (above the median values), and irregular shape were significantly associated with aneurysm rupture. After adjustment for aneurysm size, WEI (adjusted odds ratio: 8.8; 95% confidence interval, 1.1-72.6) as well as irregular shape and aspect ratio showed a strong association with rupture. CEAW is associated with rupture of intracranial aneurysm independent of aneurysm size and patient characteristics. Contrast-enhanced MR vessel wall imaging helps to identify the site of rupture in patients with multiple aneurysms.

Vessel Wall Magnetic Resonance Imaging Identifies the Site of Rupture in Patients With Multiple Intracranial Aneurysms

High-resolution magnetic resonance vessel wall imaging (MR-VWI) is increasingly used to study steno-occlusive cerebrovascular disease, but has not yet been applied to patients with aneurysmal subarachnoid hemorrhage (SAH). To study the ability of high-resolution MR-VWI to determine the site of rupture in patients with aneurysmal SAH. Medical records of patients admitted with aneurysmal SAH between December 2011 and May 2012 were reviewed. MR-VWI was routinely performed for patients treated in the IMRIS Neurovascular Suite immediately before definitive treatment of the ruptured aneurysm. We report for the first time high-resolution MR-VWI in 5 patients with aneurysmal SAH. Three patients harbored multiple intracranial aneurysms. The ruptured aneurysms demonstrated thick vessel wall enhancement in all cases. None of the associated unruptured aneurysms demonstrated this MR imaging finding. High-resolution MR-VWI identified the site of rupture in patients with aneurysmal SAH, including those patients harboring multiple intracranial aneurysms. It may represent a useful tool in the investigation of aneurysmal SAH.

Abstracts of literature

Abstracts of literature

False Localization of Rupture Site in Patients with Multiple Cerebral Aneurysms and Subarachnoid Hemorrhage

Patients with subarachnoid hemorrhage and multiple intracranial aneurysms present a unique challenge to the neurosurgeon. Unless all aneurysms can be clipped through a single craniotomy, the surgeon must accurately determine which aneurysm has ruptured. Misjudgment may result in disastrous postoperative rebleeding from the untreated but true ruptured lesion. We assessed the risk of false localization of the rupture site and subsequent rebleeding and documented the problems in predicting the true rupture site when patients have multiple intracranial aneurysms. We reviewed the records of a consecutive series of 93 patients treated over a period of 12 years who presented with their first subarachnoid hemorrhage and who had multiple intracranial aneurysms. The rupture site was determined on the basis of computed tomographic and angiographic findings, and the supposed ruptured aneurysm was clipped within 2 days of hemorrhage in each patient. Additional aneurysms that could not be accessed in the same surgical session were operated on at a later stage. All patients' records were reviewed, and all computed tomographic scans and angiograms, including repeat studies performed in some patients, were retrospectively reevaluated by the authors, who had no knowledge of the patients' clinical information. The location of the aneurysm that ruptured was verified at the time of surgery or during the autopsy in 76 patients (82%). The aneurysm that ruptured was the one predicted as ruptured by the surgeon before surgery in 69 patients (91%) and in retrospect in 72 patients (95%). Five of the 6 patients in whom the ruptured aneurysm was not correctly identified were thought to have only a single aneurysm. Four patients rebled after surgery, and 2 patients died as a result of the rebleeding. In the reported series, the most common cause of rebleeding soon after aneurysm surgery was failure to obliterate the ruptured aneurysm, usually because it was missed on the initial angiogram. The results support not only meticulous radiological investigation of all intracranial arteries before surgery but also thorough surgical inspection of the target aneurysm in all cases of subarachnoid hemorrhage even after one candidate lesion has been discovered.

False Localization of Rupture Site in Patients with Multiple Cerebral Aneurysms and Subarachnoid Hemorrhage

False Localization of Rupture Site in Patients with Multiple Cerebral Aneurysms and Subarachnoid Hemorrhage

False localization of rupture by computed tomography in bilateral internal carotid artery aneurysms

Focal clot on computed tomographic (CT) scan is one of the most reliable clues in determining the site of rupture in patients with multiple intracranial aneurysms. However, unusual presentation of clot may cause false localization of the ruptured aneurysm in bilateral aneurysms, particularly when they are located near the midline. We describe two cases of bilateral internal carotid artery (ICA) aneurysms presenting contralateral distribution of clot on CT scan. Misjudgment of rupture site by the CT scan resulted in clipping of the wrong aneurysm in one patient. Disastrous rebleeding occurred before the second operation for the ruptured one. In the other patient, the rupture site was assumed correctly despite contralateral situation of clot on CT, and both aneurysms were treated in one operative session. Adhesion and obliteration of the subarachnoid cisterns from previous hemorrhage will deviate the direction of hemorrhage and present contralateral clot on CT scan in bilateral aneurysms located near the midline as ICA aneurysms. Medial direction of rupture may obscure accurate localization of rupture side in such aneurysms.