Dong-Hun Kang

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.

Superciliary keyhole approach for small unruptured aneurysms in anterior cerebral circulation.

BACKGROUND: Neurovascular surgeons have been trying to find a solution to the problem of surgical invasiveness by applying minimally invasive keyhole approaches. OBJECTIVE: To evaluate the feasibility and surgical outcomes of a superciliary keyhole approach for unruptured intracranial aneurysms (UIAs) as an alternative to a pterional approach. METHODS: The authors report on a consecutive series of patients who underwent a superciliary approach for clipping UIAs smaller than 15 mm arising at the supraclinoid internal carotid artery (ICA), A1 segment, anterior communicating artery (ACoA), and M1 segment including the middle cerebral artery (MCA) bifurcation. The data were compared with a historical control group (n = 90) who underwent a pterional approach for UIAs. RESULTS: A total of 120 aneurysms were successfully clipped in 102 patients with a mean age of 58 years. There was no direct mortality related to the surgery, and only 1 (1.0%) patient developed significant morbidity adversely affecting the Glasgow Outcome Scale score. The superciliary approach demonstrated statistically significant advantages over the pterional approach, including a shorter operative duration (mean, 120 min), no intraoperative blood transfusion, and extremely rare postoperative epidural hemorrhages. In addition, temporalis atrophy was rare and palsy of the frontalis persisting more than 6 months only occurred in 6 patients (5.9%) and was resolved within 2 years. The overall cosmetic outcome was excellent. CONCLUSION: A superciliary approach can be a reasonable alternative to a pterional approach for small (<15 mm) UIAs arising at the supraclinoid ICA, A1, ACoA, and M1 segment including the MCA bifurcation.

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.

In Situ Rescue Bypass for Iatrogenic Avulsion of Parent Artery during Clipping Large Pericallosal Artery Aneurysm

A case of large aneurysm arising from the distal end of an azygous A2 segment is presented. Multiple clip application inadvertently tore the aneurysmal neck, resulting in near avulsion of a right pericallosal artery origin. After an unsuccessful attempt to repair the avulsion, it was treated by occlusion of the origin of the pericallosal artery and an A4-A4 anterior cerebral artery in situ bypass without neurological deficits. The surgical technique and previous reports on side-to-side in situ bypass are discussed.

Simultaneous Vertebral Artery Dissection and Contralateral Posterior Inferior Cerebellar Artery Dissecting Aneurysm

The optimal treatment and appropriate follow-up period for an unruptured vertebral artery (VA) and/or posterior inferior cerebellar artery (PICA) dissection have not been established. Decisions regarding treatment of these vascular lesions are usually based on the manifesting symptoms and changes in radiologic findings during the follow-up period. We experienced a patient who had a simultaneous unruptured VA dissection and a contralateral PICA dissecting aneurysm. We did not find such a case in other literature.