Gallengangsrekonstruktion durch in-vivo tissue-engineering mit Veneninterponat und resorbierbarem Stent im Tiermodell

Abstract

Major bile duct lesions are usually treated by a biliodigestive anastomosis which is often complicated by cholangitis. In this study a new treatment of bile duct lesions was investigated by replacing apart of the bile duct with a venous implant which has been endoluminally stented by a new bioabsorbable stent.

In 18 of 24 pigs (German Landrace, 20 – 25 kg) a segment of the internal jugular vein of 2 cm length was used for replacing apart of the common bile duct. In group I (vein group, n = 6) a median laparotomy was performed and a 2 cm long segment of the common bile duct was resected and replaced by the venous implant. In groups II and III (stent groups, n = 6) the same procedure has been carried out, additionally the venous implant has been endoluminaily stented by a absorbable stent. Group IV (n = 6) served as control with only mobilization of the common bile duct. Postoperatively, survival, general condition and weight have been observed. For investigation of the degradation of the bio-absorbable stent in group II 2 animals were sacrificed after 3, 4 and 5 months, in group III after 6 months. After surgery and sacrifice blood and tissue samples were gained and semiquantitatively scored on inflammation and fibrosis.

All operations have been carried out without complication within 90 minutes. In groups II, III and IV (control group) all animals survived in a well general condition. In group I (vein group) 3 animals died within the first 3 weeks showing a necrotic venous interponat and biliary peritonitis and another animal died within 4 months. Only 2 animals survived until 5 months, one showing a highly stenosis of the common bile duct with secondary biliary cirrhosis of the liver. In groups II and III (stent groups) all animals survived until sacrifice. The venous interponat was laminated with bile duct epithel and showed the diameter of the bio-absorbable stent. After 4 month, the stent material has been completely degraded and parallely the cholangitis has decreased. No significant biochemical changes occurred. Only 1 animal showed a kinking of the venous interponat.

The replacement of major bile duct lesions by a venous interponat in combination with the new bio-absorbable stent is easy to perform and represents an interesting alternative to the biliodigestive anastomosis because of the preservation of the Sphincter Oddi. After 4 months the new bio-absorbable stent is completely absorbed and the venous interponat is laminated with bile duct epithelia.