Hysteroscopic hydrotubation of the equine oviduct

Summary Reason for performing study Diagnostic techniques for oviductal obstruction in the mare are limited and development of a more reliable and direct method to assess oviductal patency is needed. Objective To evaluate the feasibility of hysteroscopic selective hydrotubation of the equine oviduct via videoendoscopy in standing mares. Methods Using a catheter inserted under endoscopic guidance into the uterotubal junctions of 10 mares, 5 ml of indigo carmine solution (4 mg/ml) was flushed into the oviduct. After introduction of the dye, peritoneal fluid was obtained via abdominocentesis. A colpotomy was also performed to allow introduction of a videoendoscope into the abdominal cavity to assess the presence of dye visually at the ovarian end of the oviduct. Results and conclusions In 15 of 20 (75.0%) attempts, the catheter was successfully inserted into the uterotubal junction, and dye was observed at the ampulla, fimbria, overlying the ovary or surrounding tissue. In 2 mares, the videoendoscope could not be manipulated to identify the uterotubal junction. Only one of 2 oviducts was flushed in an additional mare because insufflation of the uterus could not be maintained. The colour of the dye was evident macroscopically and spectrophotometrically in 4 of 8 mares from which peritoneal fluid was successfully collected. Potential relevance The equine oviduct can be evaluated by hysteroscopic selective hydrotubation.