An intra-abdominal chamber for continuous long-term observation of the sheep ovary

Rupture of the ovarian follicle (ovulation) is a clinically important event in reproduction, and its prediction or detection has been the object of many investigations. Direct observation is presently the only conclusive concurrent evidence of ovulation and is, therefore, necessary in investigations on the validity and precision of signals hypothesized to be time-related to ovulation. For this purpose, an ovary observation chamber, with a kink-resistant polyvinyl chloride viewing conduit, has been fabricated from resin-reinforced fibreglass, further coated with a silicone elastomer. The chamber is implanted surgically in ewes with the ovaries placed in the distal section of the chamber. The rigid fibreglass construction can withstand the normal physical activity of the animal, while the flexible portion of the chamber allows movement of the flank musculature with minimum impairment of blood supply at the ovary pedicle. A glass window permits continuous external observation and photography of both ovaries with their follicles. Both ovaries of each of 8 sheep were mounted in a chamber and, after an initial swelling, presented relatively normal morphology for 2-9 weeks. The tissue in contact with the chamber showed no adverse reaction. No infection was observed as long as the tissue-biomaterial interface near the abdominal skin was intact. In 6 of the 8 sheep implanted with the device, components of normal cyclic development have been identified by histological, photographic, or hormonal evidence.