[Experimental studies of the esophageal prosthesis with a polyvinyl alcohol hydrogel].

Though various prosthetic materials have been experimented with for use as an artificial esophagus in the past, the two main problems that have prevented successful clinical implantation of such a prosthesis were anastomotic leakage and stricture formation of the artificial esophagus. The purpose of this study is to evaluate a high water content polyvinyl alcohol hydrogel (PVA-H) for use as the esophageal prosthesis. In 10 adult mongrel dogs, the defect after resection of the intrathoracic esophagus was bridged with a PVA-H esophageal prosthesis, 5.5 cm in length and 15 mm in internal diameter with two Tefron rings, installed 2 cm from each end. The esophageal prostheses, including the anastomotic lines, were enveloped by Dacron mesh after implantation. After implantation, the prostheses were examined endoscopically and fluoroscopically. The dogs, which were sacrificed or had died, were evaluated macro- and microscopically. Among the six dogs underwent operation, one is still living 900 days after implantation. The other two dogs were sacrificed on 165 and 162 days after implantation. The remaining three dogs died of postoperative complications ranging from 25 to 81 days after implantation. The causes of death were the respiratory insufficiency after endoscopical examination, abscess formation around the prosthesis and pyothorax. Up to 2 months after implantation the esophageal prostheses were fixed to the host esophagus without stenosis. However, the prostheses were gradually dislodged due to constricture depending on the growing granulation at the proximal anastomosis. When the surviving dog was examined on the 376th day after the operation, the esophageal prosthesis fell off entirely.(ABSTRACT TRUNCATED AT 250 WORDS)