Keita Kuraishi

Development of Nanofiber-Covered Stents Using Electrospinning: In Vitro and Acute Phase In Vivo Experiments

There are some technical difficulties in treating for a broad necked aneurysm and a higher incidence of recurrence. Because of these drawbacks, more innovative techniques for superior endovascular reconstructive treatment are required. We developed a novel covered stent employing electrospinning to deposit fine polyurethane (PU) fibers onto stents. An in vitro water leak test was designed and applied prior to animal testing to estimate the performance of covered stents and to determine the appropriate amount of PU fibers on a stent. Two tenths of a milligram of PU fibers proved to be sufficient to prevent water leakage. Then, the efficacy of the covered stents to that of bare stents was compared using 10 rabbits in which model aneurysms had been formed at the right common carotid artery by the elastase method. Angiographic evaluation on day 1 posttreatment (acute phase) revealed complete occlusion of the aneurysms and the patency of the parent arteries in animals treated with covered stents. At 10 days poststenting (subacute phase), the aneurysm neck was completely covered with neointimal layer as shown by scanning electron microscopic examination. The PU-covered stent holds promise as a device for treating cerebral aneurysms.

Midline Lumbar Fusion with Cortical Bone Trajectory Screw

A novel cortical bone trajectory (CBT) screw technique provides an alternative fixation technique for lumbar spine. Trajectory of CBT screw creates a caudo-cephalad path in sagittal plane and a medio-lateral path in axial plane, and engages cortical bone in the pedicle. The theoretical advantage is that it provides enhanced screw grip and interface strength. Midline lumbar fusion (MIDLF) is composed of posterior mid-line approach, microsurgical laminectomy, and CBT screw fixation. We adopted the MIDLF technique for lumbar spondylolisthesis. Advantages of this technique include that decompression and fusion are available in the same field, and it minimizes approach-related damages. To determine whether MIDLF with CBT screw is as effective as traditional approach and it is minimum invasive technique, we studied the clinical and radiological outcomes of MIDLF. Our results indicate that MIDLF is effective and minimum invasive technique. Evidence of effectiveness of MIDLF is that patients had good recovery score, and that CBT screw technique was safety in clinical and stable in radiological. MIDLF with CBT screw provides the surgeon with additional options for fixation. This technique is most likely to be useful for treating lumbar spondylolisthesis in combination with midline decompression and insertion of an interbody graft, such as the transforaminal lumbar interbody fusion or posterior lumbar interbody fusion techniques.

Onion-skin Hemifacial Dysesthesia Successfully Treated with C2–4 Anterior Cervical Decompression and Fusion: A Case Report

A 49-year-old man with cervical spondylosis at the C2–4 level presented with onion-skin hemifacial dysesthesia in addition to the right extremities. C2–4 anterior cervical decompression and fusion were performed. Onion-skin hemifacial pain disappeared after surgery. Although we cannot conclude the etiology of the pain was either referred pain or direct injury to the spinal trigeminal nucleus, cervical spondylosis at the middle cervical level has a possibility to present facial pain.