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Biomedical subjects

Y Fujihara

Publications and source records attributed to Y Fujihara.

8 recordsLinked to original sources

[Clinical evaluation of stent placement for tracheal and bronchial stenosis].

Expandable metallic stents were successfully introduced in 7 patients, including 4 with left main bronchial stenosis caused by bronchopulmonary tuberculosis, 2 with main bronchial stenosis caused by lung cancer and one with tracheal stenosis caused by adenoid cystic carcinoma. The length of stenosis was 1.5-5 cm. The stents were 1.5-2.5 cm long with barbs, and their full expanded diameter was 1.5 cm. Balloon dilatation was performed before stenting in all cases. The stents were inserted by using a 10-12 Fr catheter. In all patients except the one with tracheal stenosis, stents were introduced under local anesthesia without any difficulties. No migration of stents occurred. After stent placement, there were no respiratory difficulties, and radionuclide lung perfusion scan and chest radiographic findings such as lung atelectasis showed marked improvement in three cases. Combined therapy of stent placement and bronchial arterial infusion chemotherapy showed marked effectiveness in one case with lung cancer. Expandable metallic stents were very useful in eliminating tracheobronchial stenosis symptoms.

Adult

[Experimental study of water jet angioplasty].

A newly invented angioplasty by using water jet energy was investigated for evaluating its safety and effectiveness in 3 dogs. The water jet was produced from a small tip nozzle (0.2 mm in diameter) of catheter by injecting 20 ml of diluted contrast medium. By using this method recanalization of femoral arterial occlusion produced by fresh thrombi was achieved in all 3 dogs. Post recanalization angiography showed no apparent small vessel occlusions. Injection apart more than 5 mm from the inner surface of human aorta provoked no apparent changes histopathologically. Water jet angioplasty may be useful in treating vascular occlusive disease.

Animals

[Experimental study of endoesophageal and intestinal expandable metallic stent placement].

Gianturco expandable metallic stents were implanted into the esophagus and small intestine of 10 rabbits in order to evaluate the influence of wire stents on the gastrointestinal tract. The stents were constructed of 0.010 inch stainless steel wire. The relaxed diameter of the stents was 12-14 mm and the length was 10 mm. Except for one stent placed in the small intestine, the stents did not migrate and were covered with thickening mucosal epithelium. The mucosal inflammatory changes were slight, but severe intestinal adhesions were noted. The findings in the two groups were not significantly different at three and six weeks. Five rabbits died within three weeks of intestinal disorders caused by severe intestinal adhesions and/or perforations. The experimental data showed that implantation of metallic wire stents into the gastrointestinal tract resulted in severe damage to the esophagus and small intestine of rabbits.

Animals

[Experimental study of the intraurethral placement of expandable metallic stents].

Various types of Gianturco expandable metallic stents were implanted into the urethra of four dogs in order to evaluate the suitable expandability of the stents in urethra and also to determine the effect of the stents on the urethral wall. The stent of 1.5 cm in length and constructed of 0.010 inch round stainless steel wire with twelve zigzag bends showed the suitable expandability on the canine urethra compared to the other stents. The urethra remained patent and the inflammatory changes on the urethral wall were moderately noted. No hematuria or calcifications around the stents were noted in any dogs. The experimental data showed a potential clinical application.

Animals

[In vitro study of radiofrequency thermal angioplasty].

We performed some in vitro experiments using a radiofrequency thermal angioplasty instrument. The distribution of heat emitted from the hot tip of the device was evaluated in an agar phantom by thermography and it produced a concentric circular pattern. The temperature of the hot tip was about 290 degrees C when measured by thermocouples in the air. When the RF probe approached perpendicularly to the cadaver arterial wall, a crater with charring and coagulating necrosis was formed. However, when the RF probe traveled parallel to the arterial wall, as in normal practice, it did not seem to perforate the artery. The device could ablate non-calcified atheromatous plaque.

Angioplasty, Balloon

[Clinical experience of percutaneous transluminal angioplasty and expandable metallic stent placement for Budd-Chiari syndrome with massive thrombus in the inferior vena cava; report of a case].

A 72-year-old female who had suffered from lower extremity edema and liver cirrhosis due to Budd-Chiari syndrome with massive thrombus in IVC was treated by PTA and placement of self-expandable metallic stent. Thrombolysis therapy after PTA was very effective. Five months later, she had no clinical symptom due to IVC stenosis.

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