Function and structure of the rabbit oviduct following fimbriectomy. I. Distal ampullary salpingostomy.

The fimbria has long been considered an indispensable portion of the fallopian tube. To test this hypothesis, the fimbria and up to one-half of the adjoining ampulla of the left oviduct were resected by microsurgery in 13 New Zealand White does. The remaining distal ampulla was subjected to a cuff salpingostomy. Following a convalescence of 4 to 8 weeks and induced ovulation, 6 of the 11 resected oviducts apprehended ova and 29% of the total number ovulated ipsilaterally, whereas the right control oviducts retrieved 77% of the corresponding ova. Direct observation in vivo showed that the ova adhered to the neofimbria and that subsequent transport across the everted, hypertrophied ampullary mucosal folds into the tubal lumen took place readily. Scanning electron microscopy of the "neofimbria" and adjoining distal ampulla demonstrated populations of ciliated and secretory cells that were similar to those of the contralateral intact fimbria. This information challenges the concept of fimbrial indispensability and depicts the fimbriated ostium of a distal ampullary cuff salpingostomy as having an adequate function, albeit less efficient than normal