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Expandable metallic stents were successfully introduced in 12 patients; 6 with superior vena cava (SVC) obstruction due to tumor invasion or lymph node metastases, 3 with inferior vena cava (IVC) obstruction or stenosis due to lymph node metastases or hepatic tumor, one with common iliac vein (CIV) obstruction due to lymph node metastases, one with idiopathic obstruction of the hepatic IVC and Budd-Chiari syndrome, and one with CIV obstruction following a dialysis shunt. The length of the lesions was between 2 and 15 cm. Multiple (2-7) stents in tandem were inserted percutaneously from a femoral venous approach through a 12 to 16 F (4.0-5.3 mm) Teflon sheath. Postoperatively, all 12 patients became free from symptoms such as SVC syndrome or IVC syndrome. In 11 patients, the symptoms did not recur during the follow-up periods of 1 to 21 months.

The expansile force of self-expanding metallic stents is currently estimated only by wall-distending pressure (P). We estimated the expansile force of the stent not only by P but also by F, the degree of embedding into the vessel wall defined as force per unit length of wire. P and F were thought to be useful in selecting the best stent.

Gianturco expandable metallic stents were successfully placed in 4 patients with arterial occlusive disease: aortic obstruction or stenosis due to aortitis (n = 2), dissecting aneurysm (n = 1) and arteriosclerotic obstruction of the iliac artery (n = 1). The length of lesion was from 2 to 15 cm. In one case of aortitis (case 1), eleven stents (5 and 6 stents in tandem connected by wire struts) were inserted through a 12 F Teflon sheath. In another aortitis case (case 2) 4 stents in tandem were inserted through a 10 F sheath. In the two cases the sheaths were introduced by femoral arteriotomy. In case 3 and 4 two or four stents in tandem were placed through a 8 F long sheath which was introduced via the femoral artery by Seldinger method. Symptoms disappeared after placement of stents in all four cases. Our results showed the usefulness of expandable metallic stents in the treatment of arterial occlusive diseases.

Various types of Gianturco zig-zag wire stent were implanted into the tracheas of 4 dogs to define the suitable characteristics of the endotracheal wire stent in these animals. The stents were constructed of 0.45, 0.40, and 0.33 mm stainless steel wire. The diameter of the fully expanded stents was 3 cm and their lengths were 2, 3, and 4 cm. The 2 cm stent constructed of 0.33 mm wire showed minimum pathologic changes of the trachea of the dog compared to the other stents, and at the same time had a complete covering of ciliated columnar epithelium over the stent surface.

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.

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.

A 41-year-old female who had suffered from a severe left main bronchial stenosis due to bronchial tuberculosis was treated by implantation of self-expandable metallic stent after dilating the stenosis by balloon catheter. After placing the stent symptoms such as dyspnea were disappeared completely. Four months later, the patient can tolerate to do jogging.

Expandable metallic stent was successfully introduced to 5 patients including idiopathic obstruction of the hepatic portion of the inferior vena cava (1 case), superior vena cava obstruction from metastatic lymphnodes swelling (2 cases) and IVC obstructions from liver metastases or lymphnodes metastases (2 cases). The obstructions were 4-14 cm long in the case of venous obstructions due to lymphnodes metastases and 2 cm long in the case of idiopathic hepatic IVC obstruction. In all cases, the stents were introduced by using 12-16 Fr catheter percutaneously without any complications. The stent used was connected up to 7 pieces by using wire struts depending length of the obstructions. However the stents connected more than 5 pieces were difficult to advance through the catheter. The patients who had been treated with stents had been free from hazardous complications such as lower extremity swelling, and pain.

Various types of expandable metallic stents were implanted into the trachea, esophagus and urethra of five dogs. After 3-16 weeks of observation, the dogs were killed, and the trachea, esophagus and urethra were examined grossly and histologically. As a result, in order of embedding rank and inflammation degree around the stent wire was esophagus, trachea and urethra.

Nowadays expansile force of self-expandable metallic stent is estimated by only wall-distending pressure P. We estimated the expansile force of the stent by not only P but also F. F expressed the degree of digging into the vessel wall and was defined as a force per one unit length of wire. P and F were thought to be useful in selecting the best stent. We also introduced the procedure of stent production.

Various types of Gianturco zig-zag wire stents were implanted into the trachea of three dogs in order to evaluate the suitable conditions of the endotracheal wire stent. The stents were constructed of 0.018, 0.016 and 0.013 inch stainless steel wire respectively. The relaxed diameter of the stents was 3.0 cm and their length were 2 cm, 3 cm, and 4 cm respectively. The stent of 2 cm in length and constructed of 0.013 inch showed minimum pathologic changes to the trachea of the dog compared to the other stents, and also showed the covering of ciliated, columnar epithelium over the stent surface. The experimental data showed that it was possible to use the stent in the tracheobronchial tree of dogs and also showed a potential clinical application.