An initial report (Bennett et al. 2002) using this technique noted that eight of 12 mares diagnosed with bilateral occlusions and five of six mares with unilateral oviductal occlusion became pregnant on the first cycle after the flush procedure.
Normograde Oviductal Flush (Laparoscopic Approach) Technique
Standing procedure.
The mare is fasted for 24 hours prior to surgery.
Antibiotics and flunixin meglumine (1.1 mg/kg, IV, s.i.d.) are administered prior to surgery and after surgery as needed.
The mare is appropriately sedated; additional sedation may be required and administered as needed. In the original paper a combination of detomidine hydrochloride (0.01 mg/kg, IV) and butorphanol tartrate (0.01 mg/kg, IV) were administered.
The paralumbar fossa is prepared for laparoscopic surgery.
A local anesthetic is placed into the locations for the portal sites.
Three instrument portals are created and one portal for the laparoscope (Figure 29.1). The abdomen is insufflated with CO2 to allow for visualization of the internal abdominal structures.
A pair of laparoscopic Babcock forceps or oviductal forceps are used to grasp and open the edges of the infundibulum to view the ostium of the oviduct.
The balloon catheter is inserted into a guide sleeve and passed into the ostium and advanced distally toward the ampulla.
The cuff is inflated with 1.0–1.5 ml of air.
One Babcock forceps is removed from the infundibulum and repositioned behind the balloon cuff to secure the catheter in place during the flush procedure
The oviduct is flushed with 20 ml of sterile methylene blue solution.
The procedure is subsequently performed on the contralateral oviduct.
Hysteroscopy to visualize the oviductal papilla is performed during the flush to determine if the dye solution passed through each oviduct into the uterus.
The portal incisions are closed in a routine manner.
Figure 29.1 Landmarks for instrument portals: 1 is the laparoscopic portal; 2 and 3 are locations for the portals for the forceps; and 4 is the portal for the guide sleeve and catheter.
Comments
The original paper (Köllmann et al. 2011) compared flank laparoscopy with a transvaginal laparoscopic approach. The transvaginal approach was not successful and consequently is not discussed in this chapter. The major advantages of the laparoscopic procedure as compared with laparotomy are elimination of the need for general anesthesia and a minimally invasive approach. Disadvantages include costs of laparoscopic equipment and the clinical expertise needed to perform the procedure.
Additional Comments
Overall, flushing the oviducts provides diagnostic information on oviductal patency and at the same time often provides therapeutic intervention in affected mares. In regard to the latter, it has been suggested that removing oviductal masses via the normograde approach may be more difficult compared with the retrograde approach, as the luminal diameter of the isthmus is significantly smaller than the ampulla.
A concern for all the approaches discussed is the need to provide significant pressure during the flush to successfully relieve blockage(s) without rupturing the oviduct. It may be possible to reduce the risk by systemic administration of N‐butylscopolammonium bromide and/or local application of prostaglandin E2 gel onto the surface of the oviduct or the UTJ prior to the flush.
To avoid this risk of rupture of the oviduct altogether, the purely therapeutic option of applicating PGE2 to either the oviductal surface or the UTJ (without first checking oviductal patency) can also be considered in mares suspected of having oviductal issues (see Chapters 30 and 31).
References
1 Bennett SD, Griffin RL, Rhoads WS. 2002. Surgical evaluation of oviduct disease and patency in the mare. Proc Annu Conv Am Assoc Eq Pract 48: 347–9.
2 Kollmann M, Rötting A, Heberling A, Sieme H. 2011. Laparoscopic techniques for investigating the equine oviduct. Eq Vet J 43: 106–11.
3 Zent WW, Liu IKM, Spirito MA. 1993. Oviduct flushing as a treatment for infertility in the mare. Eq Vet J Suppl 15: 47–8.
Further Reading
1 Arnold CE, Love CC. 2013. Laparoscopic evaluation of oviductal patency in the standing mare. Theriogenology 79: 905–10.
2 Bennett SD. 2007. Diagnosis of oviductal disorders and diagnostic techniques. In: Samper JC, Pycock JF, McKinnon AO (eds). Current Therapy in Equine Reproduction. St Louis, MI: Saunders Elsevier, pp. 78–82.
3 Inoue Y. 2013. Hysteroscopic hydrotubation of the equine oviduct. Eq Vet J 45:761–65.
4 Inoue Y, Sekiguchi M. 2018. Clinical application of hysteroscopic hydrotubation for unexplained fertility in the mare. Eq Vet J 50: 470–3.
30 Prostaglandin E2 Treatment for Blocked Oviducts
Patrick M. McCue,1 Sofie Sitters2 and Charles F. Scoggin3
1 Equine Reproduction Laboratory, Colorado State University, USA
2 Amsterdam, The Netherlands
3 Rood and Riddle Equine Hospital, USA
Introduction
Studies have reported that oviducts (uterine tubes) of middle aged and older mares may contain gelatinous masses of collagen, fibroblasts, and debris which can occlude the lumen of the oviduct. This may lead to a reduction in fertility by either preventing sperm from reaching the site of fertilization or preventing embryos from reaching the uterus. The frequency with which clinical obstructions occur is unknown. However, clinical studies have reported that topical administration of prostaglandin E2 (PGE2) onto the surface of the oviduct in mares with unexplained fertility has resulted in a resumption in fertility in a high proportion of treated mares.
The technique is performed via laparoscopy and involves direct visualization of the serosal surface of the oviduct, ovary, and their mesenteric attachments. It is performed with
