Laparoscopy for Blocked Oviducts
In recent years Scone Equine Hospital has introduced a groundbreaking procedure in previously infertile broodmares. Prostaglandin is placed under laparoscopic visualisation onto the oviduct when a blocked oviduct is suspected of causing infertility. This innovation involves standing laparoscopy, placing a long camera from the horse’s flank into the abdomen to get visual access to the oviduct and Prostaglandin is then applied directly onto the duct to clear any blockage and facilitate movement of a fertilised egg into the uterus. Approximately 60 mares have had this procedure performed resulting in an 80% pregnancy rate across the group. Many of these mares had not been pregnant for at least two years, and some for up to four years.
Non-permanent blockage of the oviduct is now a recognised cause of infertility in a mare particularly when the mare consistently fails to conceive despite being inseminated at the right time with a fertile stallion. The mare will also show normal function of the cervix, uterus and ovaries with no evidence of infective endometritis or chronic degenerative endometritis that might normally interfere with conception. Studies have identified the presence of oviducal masses that physically obstruct the passage of eggs.
What does the procedure involve?
At around 4 days after ovulation and following natural service, the mare is sedated, placed in a crush and medicated. The hair is clipped from both flanks and the skin prepared for surgery. A large drape is placed across the mares’ left flank and back. Local anaesthetic is injected under the skin and into the abdominal muscles. A 12 mm trocar is passed through a 1cm incision and then replaced with a laparoscope with a 300 viewing angle. The abdomen is filled with Carbon Dioxide and the ovary visualised. A second trocar is then inserted and grasping forceps are used to thoroughly examine the entire length of the oviduct, ovary and tip of the left uterine horn. The forceps are then replaced with a 5mm injection cannula and Prostaglandin gel is then applied to the external surface of the entire length of the oviduct. The Carbon Dioxide is released from the abdomen, the skin portals closed and the entire procedure repeated on the opposite flank.
What happens after the surgery?
Mares tolerate this procedure very well. Following surgery, the mare is returned to the paddock within 24 hours and post-operative care is not necessary. The mare is later examined for pregnancy in a routine fashion.
What are the risks for this procedure?
Any surgery is not without some risk but providing the technique is undertaken correctly the risks are very low. All mares that had this procedure were grazing in a paddock within 24 hours of surgery and no complications were encountered. For further information go to Equine Surgery Risks.
When is the best time for this surgery?
The procedure is done at day 4 after ovulation to coincide with the normal time of movement of the fertilized egg from the oviduct into the uterus.
Does the mare need to have the same procedure again?
The procedure only needs to be done once in the stud season and there is good evidence to suggest that if your mare does not get pregnant during that stud season there is no need to repeat the procedure again at the beginning of the following stud season. Some mare owners elect to undertake the procedure at the beginning of the stud season to ensure any blockages are corrected prior to commencement of serving.