Search

Purpose: To evaluate which of six different commonly available stents inserted into an artery without percutaneous transluminal angioplasty (PTA) causes the least endothelial damage. To compare the degree of endothelial injury after insertion of such a stent with injury caused by PTA.Methods: Twelve healthy pigs were used in the experiments. In the first part of the study six different types of stents were inserted into the common iliac arteries. In the second part of the study self-expanding stents with large spaces between the wires were used. PTA was performed in the contralateral iliac artery. The pigs were killed immediately after the procedure and resected specimens examined after fixation, using scanning electron microscopy.Results: All procedures but two were accomplished successfully. More endothelium was preserved after insertion of self-expanding stents with large spaces between the wires, compared with stents with small spaces and balloon-expanded stents. After insertion of self-expanding stents with large spaces, 50.1% +/- 16.4% of the endothelium remained intact, compared with only 5.6% +/- 7.7% after PTA. The difference was statistically significant (p < 0.001).Conclusion: Self-expanding stents with large spaces between the wires, inserted without PTA, cause less damage to the endothelium than other stents and significantly less damage than PTA. [ABSTRACT FROM AUTHOR]

Purpose: To develop a method for isolated perfusion of the liver using radiological methods.Methods: Twenty-one pigs, weighing about 20 kg, were divided into three groups. By transjugular and transfemoral approaches two occlusion balloons were placed in the inferior vena cava cranial and caudal, respectively, to the origin of the hepatic veins. One occlusion balloon was placed transfemorally in the common hepatic artery. Another occlusion balloon was inserted in the main branch of the portal vein via the transjugular-transhepatic approach in 11 pigs (groups 1 and 2), and in 10 pigs (group 3) by a percutaneous transhepatic route. After inflation of the balloons, patency of the isolated liver circulation was evaluated by recirculation of 99Tcm-labelled human albumin during 30 min. Blood tests were obtained after 1, 3, 5, 10, 15, and 30 min to evaluate leakage from the liver to the systemic circulation.Results: Increasing leakage to the systemic circulation from the isolated liver circulation was observed in groups 1 and 2. In the third group the leakage was less than 10%.Conclusion: In an experimental animal model, isolated perfusion of the liver with minor leakage to the systemic circulation may be achieved using radiological methods. [ABSTRACT FROM AUTHOR]

A 92-year-old man with dysphagia secondary to squamous cell carcinoma of the esophagus was palliated repeatedly with endoscopic laser therapy and insertion of esophageal stents. During the treatment period of 32 months, the patient could be fed perorally while ingrowth of tumor, development of new stenoses at the edges of the stents, and breakage of one stent were encountered. A tracheosesophageal fistula developed at the upper edge of the first stent. The patient died from aspiration pneumonia. At autopsy, no cancer cells were found in the esophagus. Combined endoscopic laser treatment and stent therapy may keep a patient free from dysphagia during a long period of time and also may result in the complete disappearance of tumor growth in the esophagus. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to compare deposition of 111In-labeled platelets and neutrophils after balloon angioplasty (PTA) alone and PTA plus Wallstents.Methods: Histological investigation was performed with scanning electron microscopy (SEM). Fifty percent stenoses of both iliac arteries was created by resorbable ligature in 13 pigs. After 30 days, PTA was performed bilaterally with an additional stenting procedure done on one side. Autologous platelets were labeled and reinfused before the interventional procedure in six pigs, and labeled neutrophils were used in seven pigs. The deposition of the labeled cells was recorded in vivo over 270 min using a scintillation camera. The results were correlated with in vitro measurements.Results: Scanning revealed significant increase in platelet and neutrophil deposition at the site of the stent compared with the site where PTA alone was undertaken. In vitro measurements confirmed these differences. SEM demonstrated a fibrin lining on the stent surface and numerous adherent platelets. The adjacent arterial lumen was almost completely covered by fibrinous material. The PTA-alone site demonstrated denudation of endothelial cells and less fibrinous material, as well as platelets and leukocytes.Conclusion: The complex interaction in the response of the vessel wall and flowing blood involves both platelet and neutrophil adhesion. The self-expandable vascular endoprosthesis contributes to increased deposition of platelets and neutrophils as seen in this experimental model of nonatheromatous stenosis. [ABSTRACT FROM AUTHOR]

An 8-year-old boy with a 21/2 year history of portal hypertension and repeated bleedings from esophageal varices, was referred for treatment. The 3.5-cm-long occlusion of the portal vein was passed and the channel created was stabilized with a balloon-expandable stent; a portosystemic stent-shunt was also created. The portosystemic shunt closed spontaneously within 1 month, while the recanalized segment of the portal vein remained open. The pressure gradient between the intrahepatic and extrahepatic portal vein branches dropped from 17 mmHg to 0 mmHg. The pressure in the portal vein dropped from 30 mmHg to 17 mmHg and the bleedings stopped. The next dilation of the stent was performed 12 months later due to an increased pressure gradient; the gastroesophageal varices disappeared completely. Further dilation of the stent was planned after 2, 4, and 6 years. [ABSTRACT FROM AUTHOR]

Purpose: To present a single-centre experience with endovascular treatment of patients with severe symptoms secondary to acute pulmonary embolism (PE)., Material and Methods: Twenty-five patients were treated due to contraindications or deficient effects of systemic thrombolytic therapy. The patients were treated with a combination of fragmentation and aspiration, only aspiration, or only fragmentation, and with catheter-directed thrombolytic therapy., Results: The saturation was improved following treatment in all patients, except in one where the procedure could not be completed. There were no immediate or late procedure-related complications., Conclusions: Endovascular treatment of severe PE is a safe and efficient option in patients with failing effect or contraindication to systemic thrombolysis.