Hysteroscopic hydrotubation of the equine oviduct.

This article presents a study that explores a new technique for diagnosing oviductal obstruction in mares using hysteroscopic hydrotubation. The technique involves inserting a catheter into the uterotubal junction of the horse and flushing it with indigo carmine solution. The success of the method was confirmed by observing dye at the ovarian end of the oviduct and in the surrounding tissue.

Objective and Methodology

• The primary objective of this research was to assess the feasibility of a more direct method to evaluate oviductal patency in mares. This method, called hysteroscopic selective hydrotubation, involves inspecting the equine oviduct through the use of videoendoscopy while the horse is standing.
• The researchers used a catheter, which was introduced under endoscopic guidance, into the uterotubal junctions of ten mares. They used 5 ml of an indigo carmine solution (4 mg/ml) to flush the oviducts.
• After administering the dye, the researchers collected peritoneal fluid through a process called abdominocentesis. They also performed a colpotomy, which is a surgical incision into the vaginal wall, to introduce a videoendoscope into the abdominal cavity. This allowed them to visually check for the presence of the dye at the ovarian end of the oviduct.

Results

• The researchers were able to successfully insert the catheter into the uterotubal junction in 15 out of 20 attempts (or 75% of attempts). This allowed them to observe the presence of dye at the ampulla, fimbria, overlying the ovary, and in the surrounding tissue.
• However, in two mares, the videoendoscope could not be manipulated to identify the uterotubal junction. Also, in one mare, only one of the two oviducts was flushed because the insufflation (inflation) of the uterus could not be maintained.
• The color of the dye was visible both macroscopically and spectrophotometrically in four out of the eight mares from which peritoneal fluid was successfully collected.

Conclusions

• The results of this research show that it is possible to evaluate the equine oviduct using hysteroscopic selective hydrotubation. It presents a direct method for checking oviductal patency in mares, which is very important in diagnosing and treating reproductive problems in horses.