DSC EXAMINATION OF THE ESOPHAGUS AFTER IMPLANTATION OF SPECIAL STENTS, DESIGNED FOR THE MANAGEMENT OF ACUTE ESOPHAGUS VARICEAL BLEEDING Experimental study

Massive bleeding from esophagus varices presents a life threatening complication of portal hypertension. No effective method of treatment is available until now, that would guarantee high grade of patient wellness during the conditioning and investigation phase until the definitive treatment could be introduced. The aim of this study was to evaluate the tissue response to esophagus stents-designed for manage acute variceal bleeding - in animal experiment. Self-expandable nitinol stents were introduced into the esophagus of six porcines. Another twelve porcines were undergone the same procedure, using the new biodegradable stents made of PDO (polydioxanon). Histological investigations of the stented esophagus segments were observed after 2 and 4 weeks at the first 12 animals. To monitor the time of stent degradation, histology were performed 7 and 12 weeks after the implantation in the biodegradable group (3-3 animals). Differential scanning calorimetric examination was performed in all esophagus samples. Focal erosion of the esophagus segments was more explicit in the nitinol group at the histology. On the 7(th) week all of the biodegradable stent were in the stomach and on the 12(th) week these were completely solved. DSC examination showed significant alterations in the structure of the esophagus in both stented group compared to the healthy control. This experiment showed that the new self-expandable stents are safety and suitable procedure without deterioration of the esophageal wall. According to our DSC results the thermal denaturation of intact esophagus, its mucosa and muscle fragments revealed significant differences compared to healthy sample in favour the new biodegradable stent. Safety and efficiency in the experimental model had encouraged us to apply this method successfully patients with bleeding esophagus varices. The long term goal is to show that stent placement could be an effective way of decreasing or stabilising the acute bleeding from ruptured esophagus varices in cirrhotic patients.