Effect of lengthening the fallopian tube on fertility in the rabbit.

The effect of surgically lengthening the rabbit oviduct was investigated. In the study group, a lengthened fallopian tube was created by division of the left fallopian tube at the ampullary-isthmic junction and the right fallopian tube at the uterotubal junction. The proximal left tube and the entire right tube were mobilized to the midline, and a microsurgical anastomosis was performed with 10-0 nylon. This formed a tube that was lengthened by approximately 50%, with doubling of the isthmic region. In the control group, both tubes were divided at the ampullary-isthmic junction, and the proximal left and distal right segments were joined to form a tube of normal length. The left ovary and ampulla were resected in both groups. After the animal had been bred, a second laparotomy was performed to assess adhesion formation, document tubal patency, and establish a nidation index. The median nidation index of the control group (N = 11) was 0.89, whereas that of the lengthened group (N = 7) was 0. The nidation indices of the two groups were different, with P less than 0.01.