Dal-Soo Kim

Risk Factors and Surgical Treatment for Symptomatic Adjacent Segment Degeneration after Lumbar Spine Fusion

OBJECTIVE The present study analyzed the risk factors, prevalence and clinical results following revision surgery for adjacent segment degeneration (ASD) in patients who had undergone lumbar fusion. METHODS Over an 8-year period, we performed posterior lumbar fusion in 81 patients. Patients were followed a minimum of 2 years (mean 5.5 years). During that time, 9 patients required revision surgery due to ASD development. Four patients underwent autogenous posterolateral arthrodesis and extended transpedicle screw fixation, 4 patients underwent decompressive laminectomy and interspinous device implantation, and 1 patient underwent simple decompression. RESULTS Of the 9 of patients with clinical ASD, 33.3% (3 of 9) of patients did not have radiographic ASD on plain radiographs. Following revision surgery, the clinical results were excellent or good in 8 patients (88.9%). Age > 50 years at primary surgery was a significant risk factor for ASD development, while number of fusion levels, initial diagnosis and type of fusion were not. CONCLUSION The incidence of ASD development after lumbar surgery was 11.1% (9 of 81) in this study. Age greater than 50 was the statistically significant risk factor for ASD development. Similar successful clinical outcomes were observed after extended fusion with wide decompression or after interspinous device implantation. Given the latter procedure is less invasive, the findings suggest it may be considered a treatment alternative in selected cases but it needs further study.

Combined direct and indirect reconstructive vascular surgery on the fronto-parieto-occipital region in Moyamoya disease

Between January 1992 and December 1995, eight patients with Moyamoya disease, aged from 2 to 39 years, underwent encephalo-duro-arterio-myo-synangiosis (EDAMS) on the frontal region, superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis combined with encephalo-myo-synangiosis (EMS) on the parietal region and encephaloduro-arterio-synangiosis (EDAS) on the occipital region using the frontal and parietal branch of the STA and the occipital artery, respectively. The development of postoperative collateral formation was assessed by carotid angiography and the improvement of clinical symptoms was evaluated for over 1 year after the bypass surgery. Of the 13 sides which underwent EDAMS and STA-MCA anastomosis with EMS, 11 sides resulted in extensive revascularization on the frontoparietal region and two sides showed localized collaterals, whereas EDAS on the occipital region demonstrated extensive and localized revascularization in each four sides and no evidence of revascularization in two sides among ten sides which underwent the EDAS. The clinical improvement due to the combined reconstructive surgery was very excellent in the reduction of the incidence of transient ischemic attacks (TIA) and reversible ischemic neurologic deficits (RIND).

Early superficial temporal artery to middle cerebral artery bypass in acute ischemic stroke

OBJECTIVE To evaluate the effects and safety of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in the early stage after an acute ischemic event and the improvement of present symptoms in patients with intracranial atherosclerotic occlusive disease with stroke/stroke in progress. METHODS From 2006 to 2010, 20 patients (15 males and five females) with atherosclerotic cerebrovascular disease were treated with an STA-MCA bypass. All of the patients presented with an acute ischemic stroke or stroke in progress despite maximal medical treatment. The patients underwent an STA-MCA bypass within 7 days from symptom onset. The clinical outcome and hemodynamic study of the 20 patients were preoperatively and postoperatively investigated. A pooled analysis was performed, and the results were compared with those obtained from other delayed STA-MCA bypass studies. RESULTS Among the 20 patients who underwent an early STA-MCA bypass, fourteen (70%) patients achieved a good functional outcome (mRS 0, n=3; mRS 1, n=9; mRS 2, n=2). Prior to surgery, the mean basal regional cerebral blood flow (rCBF) and cerebrovascular reserve capacity (CVR) in the symptomatic hemisphere were 37.3±4.3 ml/100 g/min and -1.68±2.9%. The mean basal rCBF and CVR had significantly increased postoperatively, and no reperfusion-induced hemorrhage had occurred. In the pooled analysis, no significant differences were observed in the clinical outcome (P=0.328) or in the incidence of postoperative complications (P=0.516) between patients who underwent an early STA-MCA bypass and in patients who underwent a delayed STA-MCA bypass in previous studies. CONCLUSIONS In this study, which consisted of 20 carefully selected patients with acute ischemic stroke, an early STA-MCA bypass was safely and effectively performed, and in some cases, an early STA-MCA bypass resulted in rapid neurological improvement. An early STA-MCA bypass was beneficial in select patients who had acute ischemic stroke with imaging evidence of a small infarction.

Ischaemic stroke after acute intracranial haemorrhage in patients with moyamoya disease: six new cases and a short literature review

BackgroundWe report six new cases of ischaemic stroke after cerebral haemorrhage in patients with moyamoya disease (MMD) and analyse their clinical and radiological characteristics, together with cases reported in the literature, to deduce the mechanism of cerebral infarct.MethodsSix (2%) of 246 patients with MMD who were admitted to our hospitals between 1993 and 2009 suffered cerebral infarct after intracranial haemorrhage. Ten patients identified in the literature with the PubMed search engine were also included in this study. All the ischaemic lesions in these 16 patients were analysed according to their location, size, and number and were compared according to the spatial relationship between the haemorrhage and infarct, as follows: (1) anterior vs posterior involvement, (2) cortical vs subcortical involvement, (3) watershed vs non-watershed infarct, (4) small vs large infarct, (5) single vs multiple infarct, and (6) adjacent vs distant involvement.ResultsAcute synchronous multiple brain infarcts occurred in six (38%) patients and recurrent infarcts in three patients (19%). Cerebral infarcts had mainly cortical (72%), anterior (66%), and distant involvement (75%) and were large (69%) and non-watershed (66%). Adjacent infarct had significantly anterior involvement (P < 0.05), and distant infarcts tended to have cortical involvement. Non-watershed infarcts had significantly cortical involvement (P < 0.05). Watershed infarcts tended to be large. Vasospasm was confirmed either pathologically or angiographically in two patients with large cerebral infarcts.ConclusionsWe suggest that thromboembolism or vasospasm plays a crucial role in the pathogenesis of cerebral infarction after acute intracranial haemorrhage in patients with MMD.

Spontaneous Thrombolysis of Multiple Thrombi at Distal Region of Hypoplastic Vertebral Artery After Stent-assisted Angioplasty on Vertebral Artery Origin Stenosis: Angiographic Follow-up.

Vertebral artery hypoplasia (VAH) can be easily overlooked if the contralateral side vertebral artery is intact, because of compensation by the contralateral artery or cerebral collateral network. The clinical relevance and hemodynamic impact of VAH is still controversial. However, VAH has recently been considered a risk factor for posterior circulation ischemia. Ischemic stroke is seldom caused by free floating thrombi (FFT) in the artery. Pathophysiology of FFT has not yet been clarified. The state of reduced blood flow such as a vertebral artery origin stenosis may cause FFT. Their instability may make them sources of recurrent artery to artery embolism. Patients with FFT will require appropriate medical and endovascular treatment. The current case illustrates a short-term angiographic change of spontaneous thrombolysis of VAH and multiple thrombi at the distal region of the stenosed lesion after stent-assisted angioplasty for a vertebral artery origin stenosis.

Isolated Cortical Venous Thrombosis as a Mimic for Cortical Subarachnoid Hemorrhage.

Isolated cortical venous thrombosis is very rare and poorly understood. The clinical presentation is also not well described in the literature. We report here a case of isolated cortical venous thrombosis that mimicked cortical subarachnoid hemorrhage (SAH). A 62-year-old man with a history of chronic subdural hemorrhage visited our hospital with headache. Brain computed tomography (CT) revealed a linear hyperdense area in the right central sulcus (cord sign), suggestive of isolated cortical SAH. Magnetic resonance imaging (MRI) revealed susceptibility in the corresponding area. CT angiography revealed no specific finding. However, transfemoral cerebral angiography (TFCA) identified filling defects in the right cortical veins. Under isolated cortical venous thrombosis, anticoagulation therapy was used to prevent the propagation of thrombosis. The patient had no recurrence of symptoms. If a cord sign is present on noncontrast CT images, further studies (MRI/magnetic resonance venography or TFCA) should be performed in a step-wise manner. Such considerations could prevent a fatal outcome and poor prognosis.