Sonothrombolysis for intraocular fibrin formation in an animal model

Vascular diseases such as diabetic retinopathy or retinal arterial occlusion are always associated with retinal and/or choroidal vasculopathy and intravascular thrombosis is commonly found. The ultrasound (US) therapy is a recently developed technique to accelerate fibrinolysis and it is being applied to some clinical fields. The present study was to observe the effects of extraocular US exposure on intraocular fibrin, which is a deteriorating factor in various ocular diseases. Tubes containing human blood (2 mL) in the following groups were irradiated with US; US alone, US with tissue plasminogen activator (tPA), tPA alone, and saline (control). Fibrinolysis was quantified by measuring D-dimer after 2h. In rat eyes, intracameral fibrin (fibrin formation in the anterior chamber of the eye) was induced by YAG-laser-induced iris bleeding. Then, eyes in the following groups were irradiated with US; US alone, subconjunctival tPA alone, US and subconjunctival tPA, control. Intracameral fibrin was scored on day 3 (3+ maximum to 0). The temperatures of rat eyes were measured by infrared thermography. Histologic evaluation was also performed. D-dimer was increased by US with statistical significance (p <0.05) or tPA (p <0.01). D-dimer in US with tPA group was significantly higher than either US alone or tPA alone group (p <0.01). In rat eyes, the average intracameral fibrin score on day 3 was 1.4 in control group and 1.2 in subconjunctival tPA alone group; however, it decreased significantly in the US alone group (0.75; p <0.05, vs. control), US and subconjunctival tPA group (0.71; p <0.01, vs. control). The temperature was less than 34 degrees C after US exposure. No histologic damage was observed. US irradiation from outside accelerated intracameral fibrinolysis without causing apparent tissue damage. This noninvasive method might have therapeutic value for intraocular fibrin.

[A case of surgically treated left atrial myxoma early after cerebral embolism]

A 48-year-old female had been visiting the outpatient clinic for treatment of polyarthritis before she was admitted to the hospital due to consciousness disorder and right hemiplegia. Brain computed tomography revealed a small infarction in the left cerebrum. Echocardiography revealed a mass in the left atrium. She was diagnosed cerebral embolism caused by left atrial myxoma. Extirpation of left atrial myxoma was performed 16 days after the onset of cerebral infarction. The postoperative course was good. Preoperative constitutional signs such as multiple arthralgia and abnormal sensation disappeared on the 2nd postoperative day. Open heart surgery performed early after the onset of cerebral embolism is generally considered contraindicated due to problems of hemorrhagic infarction or brain edema. Because relapse of embolism may deteriorate the condition, losing the chance of surgery, extirpation of left atrial myxoma early after the onset of cerebral infarction is advisable in cases of small infarction.