To verify whether laser-induced branch retinal vein occlusion in the rabbit can be used as the experimental model for the human study. The temporal retinal vein of the right eye was occluded with argon laser photocoagulator with parameters of 500 micrometerspot size, 0.2 second duration, 150-200 microWatt power in twelve pigmented rabbits. The left eye was used as a control. An electroretinogram was taken before and 1,3,7,15 and 28 days after vein occlusion. B/a ratio and oscillatory potentials increased in the eyes with occluded veins. Comparing the pre-occlusion values with those of post-occlusion, the changes were not statistically significant. But differences between the values of right and those of left eye were significant. We can suppose that the discrepancies may result from the difference in timing of examination. In conclusion, the rabbit model of laser-induced experimental branch retinal vein occlusion may not be adequate for the study of clinical branch retinal vein occlusion.
Argon ; Humans ; Models, Theoretical ; Rabbits* ; Retinal Vein Occlusion* ; Retinal Vein* ; Retinaldehyde* ; Veins

To evaluate the electroretinographic findings in cases of branch retinal vein occlusion(BRVO), Electroretinogram(ERG) were performed according to ISCEV(International Society for Clinical Electrophysiology of Vision) protocol in 17 unilateral BRVO patients. According to fluorescein angiographic acute stage group, hemorrhagic area of fundus was evaluated from retinal photo obtained by fundus camera. And correlation between hemorrhagic area and ERG was evaluated In acute stage group, the b-wave amplitude and b/a ratio of scotopic maximal combined response and oscillatory potential were significantly decreased at the affected eye compared unaffected eye. These findings were not found in chronic stage group. The relationship between hemorrhagic area and ERG finding was not detected in acute stage group. ERG findings in the acute stage of BRVO show that main pathologic lesion of BRVO is located in the inner retinal layer and inner retinal circulation. With further follow-up study, It is possible to use ERG data as a predictor of the course of BRVO.
Electrophysiology ; Fluorescein ; Follow-Up Studies ; Humans ; Retinal Vein Occlusion* ; Retinal Vein* ; Retinaldehyde*

OBJECTIVE: Few studies have reported the outcome of mechanical thrombectomy with Solitaire stent retrival (MTSR) in subtypes of acute ischemic stroke. The purpose of this study was to evaluate the efficacy and result of MTSR in acute cardioembolic stroke. METHODS: Twenty consecutive patients with acute cardioembolic stroke were treated by MTSR. The angiographic outcome was assessed by thrombolysis in cerebral infarction (TICI) grade. TICI grade 2a, 2b, or 3 with a measurable thrombus that was retrieved was considered as a success when MTSR was performed in the site of primary vessel occlusion, and TICI grade 2b or 3 was considered as a success when final result was reported. Clinical and radiological results were compared between two groups divided on the basis of final results of MTSR. Persistent thrombus compression sign on angiogram was defined as a stenotic, tapered arterial lumen whenever temporary stenting was performed. The clinical outcomes were assessed by the modified Rankin Scale (mRS) at 3 months. RESULTS: The failure rate of MTSR was 20% (4/20) and other modalities, such as permanent stenting, were needed. Final successful recanalization (TICI grade 2b or 3) was 80% when other treatments were included. The rate of good outcome (mRS≤2) was 35% at the 3-month follow-up. Failure of MTSR was significantly correlated with persistent thrombus compression sign (p=0.001). CONCLUSION: Some cases of cardioembolic stroke are resistant to MTSR and may need other treatment modalities. Careful interpretation of angiogram may be helpful to the decision.
Cerebral Infarction ; Follow-Up Studies ; Humans ; Intracranial Embolism ; Mechanical Thrombolysis ; Stents* ; Stroke* ; Thrombectomy* ; Thrombosis

OBJECTIVE: Traditionally, it is generally recommended that antiplatelet agent should be discontinued before surgery. However, decompressive craniectomy (DC) in patients with traumatic brain injury (TBI) is performed emergently in most cases. Therefore, DC cannot be delayed to the time when the effect of antiplatelet agent on bleeding tendency dissipates. In this study, we evaluated the effect of preinjury antiplatelet therapy on hemorrhagic complications after emergent DC in patients with TBI. METHODS: We retrospectively investigated patients with TBI who underwent emergent DC between 2006 and 2015. The patients were separated into two groups according to the use of preinjury antiplatelet agent: group 1 (patients taking antiplatelet agent) and group 2 (patients not taking antiplatelet agent). The rate of hemorrhagic complications (postoperative epidural or subdural hemorrhage, newly developed, or progression of preexisting contusion or intracerebral hemorrhage within the field of DC) and the rate of reoperation within 7 days after DC were compared between two groups. RESULTS: During the study period, DC was performed in 90 patients. Of them, 19 patients were taking antiplatelet agent before TBI. The rate of hemorrhagic complications was 52.6% (10/19) in group 1 and 46.5% (33/71) in group 2 (p=0.633). The rate of reoperation was 36.8% (7/19) in group 1 and 36.6% (26/71) in group 2 (p=0.986). No statistical difference was found between two groups. CONCLUSION: Preinjury antiplatelet therapy did not influence the rate of hemorrhagic complications and reoperation after DC. Emergent DC in patients with TBI should not be delayed because of preinjury antiplatelet therapy.
Brain Injuries* ; Cerebral Hemorrhage ; Contusions ; Decompressive Craniectomy* ; Hematoma, Subdural ; Hemorrhage ; Humans ; Platelet Aggregation Inhibitors ; Postoperative Hemorrhage ; Reoperation ; Retrospective Studies