Yoshikazu Okuda

Clinical Outcome of Stenting in Superior Vena Cava Syndrome Associated with Malignant Tumors Comparison with conventional treatment

Purpose: We analyzed the clinical outcome of treatment with the expandable metallic stent (EMS) for the superior vena cava (SVC) syndrome associated with malignant tumors, and the results were compared with those of radiotherapy. Material and Methods: of 33 patients with the SVC syndrome, 23 were treated by Gianturco EMS placement and 10 were treated by radiotherapy and/or chemotherapy alone. of the 23 EMS patients, 11 had treatment before EMS placement and 12 had no treatment before EMS placement. Results: After stenting, the clinical symptoms disappeared in 78% (18/23) of the patients, i.e. in 50% of the patients with intraluminal tumors, and in 93% of those with extrinsic compression. the clinical symptoms improved in 80% of patients who received radiotherapy. the mean duration of survival was 145 days in patients who underwent stenting, and 146 days in those receiving radiotherapy. However, the survival period differed significantly between patients with intraluminal tumors (44.9 days) and those with extrinsic compression (198.6 days). Between patients with previous treatment and those with no previous treatment, there was no significant difference in response rate or in survival period which were 82% versus 75%, and 127 days versus 162 days, respectively. Conclusion: the clinical symptoms showed similar improvement in patients receiving EMS placement or radiotherapy. EMS placement was effective in relieving clinical symptoms in patients who had failed to respond to radiotherapy.

Treatment of Takayasu's aortitis with self-expanding metallic stents (Gianturco stents) in two patients

Gianturco self-expanding metallic stents were successfully placed to treat incomplete balloon dilatation of the abdominal aorta in 2 patients with Takayasus aortitis. In 1 case eleven 1-cm long, 1-cm diameter stents were inserted in tandem to bridge a long stenosis. In the other patient, four stents 1.5 cm long, 1.5 cm in diameter were inserted in tandem to bridge what had been a complete occlusion prior to balloon angioplasty. Clinical symptoms, as well as angiographic findings, improved significantly after placement of the stents. The patients underwent repeat aortography at 10 and 8 months, respectively, and were followed clinically for a total of 18 months and 15 months, respectively, without clinical evidence of deterioration. Our results show the usefulness of expandable metallic stents in the treatment of aortic stenosis due to Takayasus aortitis that remains unresponsive to balloon dilatation.

Water Jet Angioplasty — an Experimental Study

The usefulness and safety of water jet angioplasty was studied in vitro, using agar phantom and autopsied aorta, and in vivo in acute and chronic arterial occlusions in mongrel dogs. At an injection rate of 1.0 ml/s, the water jet produced erosion of the agar surface when the distance between the catheter and the agar was 1 mm. With an injection rate of 1.5 ml/s, erosion was produced at a distance of 15 mm from the catheter tip. When the water jet was directed at an arterial wall, intimal ablation and ruptured elastic fibers were found histopathologically. A smaller angle between the vascular wall and the catheter was associated with less vascular damage. In vivo, water jet angioplasty was effective against acute obstructions, but not against chronic obstructions. These results suggest that water jet angioplasty may be effective against arterial obstruction due to acute thrombus.

Expandable metallic stent treatment for malignant colorectal strictures

Four patients were treated by placement of an expandable metallic stent (two Gianturco Z-stents, two Ultraflex stents) for malignant colorectal strictures. All four patients were able to defecate after stent placement. Stent migration was recognized in one patient. Two patients suffered from tenesmus after stent placement.

Percutaneous Endoscopic Retrieval and Replacement of a Knitted (Ultraflex) Biliary Stent

Abstract A knitted (Ultraflex) biliary stent became obstructed after 5 months causing recurrent jaundice in a 92-year-old man with pancreatic cancer. The obstructed stent was successfully removed percutaneously by retrieval forceps under guidance by an 8.4 Fr fiberoptic biliary endoscope. A new stent was placed. No complications were encountered.

Intraarterial Occlusion by Radiofrequency

Arterial occlusion using radiofrequency energy was performed. The length of the noninsulated part of the guidewire was 10 mm and the duration of radiofrequency supply was 20 s. Animal experiments were carried out in 17 canine arteries; 4 out of 6 arteries less than 2.3 mm in diameter were completely occluded during the 20 s radiofrequency supply. A clinical application was also successfully performed without any complications. Arterial occlusion with radiofrequency can be applied to vessels less than about 2 mm in diameter.

Letter to the Editor Re: Assessment of Reintervention with Tracheobronchial Metallic Stenting for Malignant Airway Stenoses

No Abstract

CT demonstration of portal vein remnant within metastatic liver tumor.

We describe a patient with a metastatic liver tumor that showed a cordlike shadow traversing the tumor on CT. Histopathologically, this cordlike shadow within the metastatic liver tumor was proved to be an infiltrated portal vein without blood flow surrounded by fibrous tissue. Vascular structures traversing a focal lesion may be seen not only in focal fatty infiltration or lymphoma but also in metastatic liver tumor.

Percutaneous internal fistulization of a lung abscess after incomplete external drainage

Internal drainage was performed with expandable metallic stents in a 79-year-old male with lung abscess secondary to bronchogenic carcinoma. Initial external drainage was prolonged, and internalization of drainage allowed removal of the external drainage catheter. Connection of abscess cavity to obstructed bronchus was created after passing a steerable guidewire percutaneously through the abscess into the bronchus. This new type of internal drainage technique may be applicable to patients with prolonged standard percutaneous external drainage of lung abscesses.