ABSTRACT
BACKGROUND: The stomach is usually used to substitute the diseased esophagus, which will change the physical digestive passage and results in some complications, such as back-streaming, poor food intake, and dyspepsia. If there is an artificial esophagus to replace the diseased esophagus, then the complications would be greatly reduced, and surgical procedures would be simplified. OBJECTIVE: To investigate the effects of artificial prosthesis of titanium-nickel alloy and silicone on repairing esophageal defect after part excision of esophagus. DESIGN, TIME AND SETTING: An in vivo observation experiment based on animals was performed at the animal laboratory of Second Affiliated Hospital of Guangzhou Medical College between May 1999 and May 2001. MATERIALS: Sixteen pigs of either gender, weighting 30 35 kg, were included. The artificial esophagus constructed by titanium-nickel alloy and silicone were provided by General Research Institute for Nonferrous Metals. Its length was 10 cm and its internal diameter was 20 mm. Its inner layer was made of silicone and its outer layer was titanium-nickel alloy net. METHODS: A segment of 7-cm thoracic esophagus was resected and was replaced by an artificial prosthesis constructed by titanium-nickel alloy and silicone. At 1, 2, 3, 4, 5, 6, 7, and 8 weeks, as well as 3, 4, 6, 8, 10, and 12 months after surgery, animals were sacrificed to take specimens. Sedal slices were stained by hematoxylin-eosin for pathological examination. MAIN OUTCOME MEASURES: Autopsy and histopathological findings of neo-esophagus. RESULTS: Of initial 16 pigs, 1 died owing to shock caused by hemorrhee, 1 died of excessive anesthesia, and the remaining 14 pigs survived a period from 7 days to 1 year. Following sacrifice, some vomicas containing yellow and white liquor purls on the chest wall of 4 pigs were observed, which were wrapped but did not communicate the thoracic cavity. One artificial esophagus was not in place but found in the stomach. One artificial esophagus was twisted and formed an esophagus diverticulum. The false passage around the prosthesis formed so long as the animals survived more than 1 week, which was called as neo-esophagus. The neo-esophagus was constructed primadly by granulation tissue within approximately 2 weeks, and then fibrous connective tissue replaced it. Four weeks later, esophageal epithelial cells covered the internal cavity of the "nee-esophagus". At this time, neonatal smooth muscle cells could be observed, but gland regeneration was not found. Following artificial esophagus displacement, the middle segment of "neo-esophagus" presented with stenosis to different degrees. The stenosis segment tended to stabilize with time (approximately 6 months later). CONCLUSION: Esophageal defect within a certain range of length can be repaired by an artificial esophagus constructed by titanium-nickel alloy and silicone.