Radiological evaluation of the patency of duodenal-esophageal anastomosis during a long postoperative follow-up: effectiveness of an alkaline reflux model in rats

André Vicente Bigolin¹, João Vicente Grossi², Juliano Hermes Maeso Montes¹, Roberto Nicola¹, Leandro Totti Cavazzola^1
1School of Medicine, Lutheran University of Brazil, Canoas; ²Hospital de Pronto Socorro de Porto Alegre, Department of Surgery, Porto Alegre, Rio Grande do Sul, Brazil

Background: Performing experimental studies has played an important role in acquiring knowledge about esophageal carcinogenesis. In this context, the choice of a more reliable experimental model requires proof of its effectiveness in order to lend greater credibility to the results. The objective of this study was to evaluate the patency of duodenal-esophageal anastomosis during long-term postoperative follow-up in rats.
Methods: This was an experimental study in which 45 female Wistar rats were used. A side-to-side anastomosis was performed, going from the anterior side of the esophagus to the second duodenal portion. A standardized radiological technique was used to carry out a contrasted radiological study of the esophagus, stomach, and duodenum during weeks 4, 12, 20, and 30 after surgery. Different contrast media were used, and the animals were divided into groups, ie, group 1 (100% barium sulfate), group 2 (50% barium sulfate), and group 3 (60% aqueous iodinated contrast media). Contrast radiographs were taken in each group at weeks 4, 12, 20, and 30 after the surgical procedure. The radiographic images were evaluated by two radiologists who were blinded regarding the contrast groups. Macroscopic evaluation of each animal was compared with the radiological findings.
Results: Postoperative mortality was 13.33%. The remaining animals were divided into study groups. All the contrast radiological examinations showed evidence of the location of the esophagus, stomach, and proximal portion of the intestine, and demonstrated the laterolateral relationship of the distal esophagus and the duodenum in the epigastric region. Patency of the anastomosis was observed at each examination period. The different contrast media used were able to demonstrate this outcome shortly after the first phase of injection. Necropsies corroborated the radiological findings.
Conclusion: Regardless of the contrast agent used, contrasted radiography revealed that side-to-side duodenal-esophageal anastomosis in rats allowed patent communication during long-term postoperative follow-up.

Keywords: gastroesophageal reflux, esophagus, adenocarcinoma, experimental neoplasm