Clinical application of hysteroscopic hydrotubation for unexplained infertility in the mare

The oviducts of 31 cyclic cows were examined to study the structure and nature of the oviductal mucosa. The general distribution of spermatozoa within the oviductal mucosa was studied in five additional cows. The oviductal infundibulum is an asymmetric funnel-shaped structure surrounding the ostium. It is divided along the free boarder of the mesosalpinx and presents one wide and one narrow side. The mucosa of the wide side possesses a system of low interconnected cords that converge distally forming primary folds. The folds on the narrow side start sharply from the free margin and fuse toward the ostium abdominale. Areas between folds throughout the lumen of the oviduct show a high degree of complex organization. Interfold spaces are occupied by secondary and small interconnected folds which join to form a system of cul-de-sacs. In the infundibulum, these cul-de-sacs open toward the ovary, while cul-de-sacs present in the caudal isthmus and in the UTJ open toward the uterus. Marked variations were observed in the oviductal epithelium depending on the oviductal segment, basal or apical areas of the folds, and phase of the oestrous cycle. Near to the time of ovulation, numerous spermatozoa were found in the periphery of the caudal isthmus within pockets of basal interfold areas, as well as within pockets and cul-de-sacs of the tubo-uterine junction. Individual spermatozoa were also observed in peripheral areas of the ampullary-isthmic junction and ampulla. The topography of the oviduct provides a complex system of regulation which may influence not only the passage of gametes and/or embryos, but also movement of fluid within the oviductal canal. Show more

Low-volume uterine flush (n=401) was performed in 308 infertile mares to diagnose endometritis. Mares evaluated were either barren after three or more breedings or had two or more unsuccessful embryo recovery attempts during consecutive cycles. Culture results were compared with cytological and histological findings, efflux clarity and pH to substantiate that the micro-organisms recovered were truly pathogens. Cytological specimens were evaluated for presence of epithelial and inflammatory cells, bacteria, yeast and debris. Endometrial biopsies (n=110) were examined for the presence of neutrophils in the stratum compactum. Micro-organisms were recovered in 282/401 (70%) of low-volume flushes; E. coli was most frequently isolated (42.2%), followed by beta hemolytic Streptococcus (37.6%). Efflux clarity of 318 flushes was clear (n=109), cloudy (n=149), or mucoid (n=60). Isolation of micro-organisms was highly associated with cloudy and mucoid effluxes (P<0.001), debris on cytological specimens (P<0.001), increased efflux pH (P<0.003), and neutrophils on endometrial biopsy (P<0.01). E. coli was associated with debris on cytological smear (P<0.002), whereas beta hemolytic Streptococcus was associated with increased efflux pH (P<0.002). Using the presence of neutrophils in a tissue specimen as the "best standard" for diagnosing endometritis, the sensitivity of flush culture was 0.71 and for flush cytology was 0.8, whereas the specificity was 0.86 and 0.67, respectively. Neutrophils in uterine flushes under-reported inflammation; only 86/282 positive cultures were positive on cytology. The clinical estimate of a contaminated (false positive) flush culture was 11%, if a false positive was defined as positive culture with clear efflux and no debris or neutrophils on cytology (26/228). In conclusion, a low-volume uterine flush was a rapid, accurate method for identifying mares with chronic endometritis. When micro-organisms were recovered, endometritis was confirmed by efflux clarity, pH and cytological findings of debris, bacteria, or neutrophils. E. coli was most commonly isolated and it appeared to differ in pathogenicity from beta hemolytic Streptococcus. Show more