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Does non-perimesencephalic type non-aneurysmal subarachnoid hemorrhage have a benign prognosis?

We reviewed and compared the clinical course and long-term prognosis of patients with non-aneurysmal subarachnoid hemorrhage (SAH) with and without a perimesencephalic pattern of hemorrhage on CT scan. In 876 patients with spontaneous SAH, 52 (5.9%) were diagnosed with non-aneurysmal SAH. Based on their CT scans, the SAH was classified as perimesencephalic non-aneurysmal SAH (PNSH) in 23 patients and non-perimesencephalic (non-PNSH) in 29 patients. The patients in the non-PNSH group were further divided into diffuse type (19 patients) and localized type (10 patients). We performed follow-up three-dimensional-CT angiography (3D-CTA) in all possible patients at least 1 year after the attack. The PNSH group had a lower rate of acute hydrocephalus (8.7%) and angiographic vasospasm (0%) complications than the non-PNSH group (37.9% and 27.6%, respectively). Only one case of rebleeding occurred in the non-PNSH group. No demonstrable source of bleeding was found on follow-up 3D-CTA, which was performed 1 year after the attack. All patients with non-aneurysmal SAH had similarly favorable long-term functional outcomes. Based on our study, patients with non-PNSH have a more complicated clinical course than those with PNSH. However, the long-term prognosis was similarly favorable for both the PNSH and non-PNSH in limited circumstances when they showed normal findings on a series of two-dimensional and 3D angiographic work-ups.

Remote Cerebellar Hemorrhage Complicated after Supratentorial Surgery: Retrospective Study with Review of Articles

OBJECTIVE Remote cerebellar hemorrhage (RCH) is one of the rare complications occurring after supratentorial surgery, and its pathomechanism is poorly understood. We report 10 cases of RCH from our institution and review 154 cases from a database in order to delineate incidence, common presentation, risk factors, and outcomes of this complication. In addition, the means of prevention are discussed. METHODS We reviewed the medical records of 10 patients who experienced RCH after undergoing supratentorial surgery at our institution between 2001 and 2008. A database search in Medline revealed 154 cases of RCH in the English literature. Characteristic features were analyzed and compared. RESULTS There were 10 cases of RCH among 3307 supratentorial surgery cases, indicating a 0.3% incidence. All patients had characteristic imaging features of RCH, namely a streaky bleeding pattern in the superior folia of the cerebellum. Seven patients had a history of preoperative hypertension. Four cases were related to cerebral aneurysms, and other four developed after the removal of brain tumors. Cerebrospinal fluid (CSF) drainage apparatuses were installed postoperatively in all cases. Outcomes according to modified Rankin scale (mRS) were good in 7 patients, with 1 fatal case. CONCLUSION RCH is a rare complication after supratentorial surgery, and the exact etiology still remains uncertain. Hypertension and perioperative loss of CSF seem positively correlated with RCH, but no single risk factor is totally responsible. Patients with RCH should be closely observed to improve their prognosis.

Anterior interhemispheric approach for distal anterior cerebral artery aneurysm surgery: preoperative analysis of the venous anatomy can help to avoid venous infarction.

SummaryBackground. The anterior interhemispheric approach is a well-known operative technique for a distal anterior cerebral artery (ACA) aneurysm. However, a frontal parasagittal bridging vein is occasionally sacrificed in this approach, creating a risk of postoperative venous infarction.Method. To evaluate the risk of venous infarction, the current study investigated the venous phase of preoperative angiograms and postoperative CT scans for 20 patients in whom a parasagittal bridging vein had been sacrificed during the anterior interhemispheric approach. The draining territory index of the sacrificed bridging vein (DTISBV), draining territory index of the adjacent collateral ascending draining veins (DTIADV), and drainage impediment index (DII) were all calculated, plus the development of the superficial Sylvian vein (SSV) was evaluated.Findings. Extensive postoperative venous infarction occurred in two of four patients with an aplastic SSV, for whom the DTISBVs were 41% and 43%, and the DIIs 26% and 37%. Among 16 patients with a normal SSV, two patients suffered postoperative venous congestion, and their DTISBVs were 40% and 50%, and their DIIs 21% and 30%. The other 14 patients without any postoperative venous drainage problems had a lower DTISBV and DII, where the DTISBV was 22.3±6.8% (mean±SD) and the DII 4.3±8.1%.Conclusions. The present results suggest that the venous phase of a preoperative angiogram should be carefully evaluated before distal ACA aneurysm surgery. In particular, a DTISBV and DII over 50% and 30%, respectively, in patients with a normal SSV and over 40% and 25%, respectively, in patients with an aplastic SSV were found to be critical to the production of postoperative venous infarction.

Early ventriculoperitoneal shunt placement after severe aneurysmal subarachnoid hemorrhage: role of intraventricular hemorrhage and shunt function.

OBJECTIVEThis study investigated the outcome of early shunt placement in patients with poor-grade subarachnoid hemorrhage and the effect of intraventricular hemorrhage (IVH) and high proteinaceous cerebrospinal fluid (CSF) on subsequent shunt performance. METHODSThis study included 33 consecutive patients with initial Fisher grade (3/4) subarachnoid hemorrhage who had undergone conversion from external ventricular drainage (EVD) to a ventriculoperitoneal (VP) shunt and whose computed tomography scan showed IVH at the time of shunt placement. Early weaning from an EVD and conversion to a VP shunt was performed irrespective of IVH or high protein content in the CSF. RESULTSThe mean interval from EVD to VP shunt placement was 6.4 days. The mean volume of IVH was 9.44 mL, and the mean value of IVH/whole ventricle volume ratio (ie, percentage of blood suspension in the CSF) was 9.81%. The mean perioperative protein level in the CSF was 149 mg/dL. During the follow-up period, 2 patients (6.1%) required VP shunt placement, and no patients experienced complications of ventriculitis or shunt-related infection. CONCLUSIONBased on our data, earlier EVD weaning and shunt placement can effectively treat subarachnoid hemorrhage–induced hydrocephalus in patients with severe subarachnoid hemorrhage. This procedure resulted in no shunt-related infections and a 6.1% revision rate. There were fewer adverse effects of IVH and protein on shunt performance. Therefore, weaning from an EVD and conversion to a permanent VP shunt need not be delayed because of IVH or proteinaceous CSF.

Revision of Paine's technique for intraoperative ventricular puncture

BACKGROUND The aim of this study was to determine the ideal point for a ventricular puncture in pterional craniotomies. METHODS Using a circle that had its center around the junction of the columns of the fornix and conforming to the surface of the frontal lobe on an axial computed tomography scan 2.5 cm superior to the lateral orbital roof, we simulated the introduction of a catheter perpendicular to the cortex by drawing the radii of the circle in 70 patients with an acute subarachnoid hemorrhage. The cortical point at which perpendicular puncture provides the best trajectory for ventricular access, traversing the least brain tissue and avoiding important brain structures, such as the head of the caudate nucleus, anterior limb of the internal capsule, and Brocas cortex in the dominant hemisphere, was measured. RESULTS The new landmark was located at the point 44 +/- 4 mm anterior to the sylvian fissure on the level of 2.5 cm superior to the lateral orbital roof and was consistent regardless of the ventricular dimensions and sex. Clinical trial of the ventriculostomy in 32 patients with a ruptured aneurysm approved the new landmark. CONCLUSIONS An intraoperative ventriculostomy can be performed safely and reliably using the new landmark 2.5 cm superior to the lateral orbital roof and 4.5 cm anterior to the sylvian fissure in aneurysm surgery using a pterional craniotomy.

Acute serious rebleeding after angiographically successful coil embolization of ruptured cerebral aneurysms

PurposeThe present study investigated the incidence of acute rebleeding after successful coil embolization of a ruptured cerebral aneurysm, including clinical outcomes, and possible mechanisms of the events other than coil compaction and/or incomplete embolization.Materials and methodsThis study included 591 consecutive patients who presented with aneurysmal subarachnoid hemorrhage, were treated with coil embolization, and whose post-procedural angiography revealed successful embolization. Data were collected retrospectively from six patients who showed acute rebleeding despite that angiographically successful coil embolization was achieved. All clinical, radiological data and intraoperative videos were reviewed to identify causative factors which could have contributed to the occurrence of rebleeding.ResultsIncidence of acute rebleeding after successful coil embolization of ruptured cerebral aneurysm was 1.0% (6/591). In all of these six patients, complete angiographic occlusion was achieved except in one case where a small residual neck was intentionally left to avoid compromise of the parent artery. Four of the six patients showed poor clinical courses, either died or recovered with severe disability. Whenever possible, we performed an immediate craniotomy for exploration and additional clipping. Based on intraoperative findings, we hypothesized that uneven distribution of the coil masses and spontaneous resolution of thrombus among the strands of coil (inter-coil-loop thrombolysis) could be possible mechanisms of rebleeding.ConclusionAcute rebleeding is extremely rare, but is possible as a complication of coil embolization of a ruptured cerebral aneurysm even when a case is angiographically successful. The higher degree of morbidity and mortality is a major concern. Therefore, further investigation to discover risk factors and causative mechanisms for such a complication is sorely needed.

Saccular Aneurysm at the Anterior Communicating Artery Complex Associated with an Accessory Middle Cerebral Artery : Report of Two Cases and Review of the Literature

Accessory middle cerebral artery (MCA) is an infrequent vascular anomaly of the brain. Cerebral aneurysms associated with this anomalous artery are also very rare. To our knowledge, there have only been ten previous reports of an aneurysm associated with accessory MCA. The authors present two patients with accessory MCA-related aneurysms. A 38-year-old male and a 59-year-old female both presented with sudden-onset severe headache. In both patients, computed tomography (CT) scan revealed subarachnoid hemorrhage. A subsequent angiogram demonstrated an accessory MCA arising from the anterior cerebral artery (ACA) and a saccular aneurysm at the anterior communicating artery (ACoA) complex associated with an accessory MCA. Surgical clipping allowed for complete exclusion of the aneurysm from the arterial circulation. Based on our review of the ten cases of aneurysms associated with accessory MCA documented in the literature, we suggest that accessory MCA-related aneurysms can be classified according to whether the accessory MCA originates from the proximal A1 segment or from the ACoA complex. We also emphasize the importance of precise interpretation of preoperative angiograms and intraoperative precaution in determining the presence of this anomalous artery prior to temporary clip placement.

Occluded vascular stump mimicking middle cerebral artery bifurcation aneurysm: report of 2 cases

BACKGROUND An intracranial stump of an occluded vessel is a rare but important aneurysm mimic. We present 2 cases of middle trunk atresia of the trifurcated MCA, in which the proximal stump of the atretic vessel mimics an MCA bifurcation aneurysm in angiograms. CASE DESCRIPTION Both patients were referred to the authors with a presumptive diagnosis of an unruptured asymptomatic aneurysm at the MCA bifurcation that was found in an MR angiogram. The aneurysmal shape was conical in one case and in the other case, globoid and saccular. Careful examination of the catheter angiograms allowed us to notice the fine moyamoya phenomenon localized at adjacent M2 segments, in addition to the aneurysmal lesions. Surgical exploration revealed an MCA trifurcation instead of a bifurcation. The middle trunk of the MCA was atretic, showing a thin and white cordlike appearance, and its proximal end was a vascular stump instead of a true aneurysm. Adjacent M2 segments emitted fine perforating vessels in accordance with the moyamoya phenomenon at angiography. CONCLUSION In angiographic examinations, when an aneurysmal lesion is present at the MCA bifurcation in association with the moyamoya phenomenon at adjacent M2 trunks, the proximal stump of an atretic middle trunk of the MCA instead of a true aneurysm should be suspected and treated appropriately.