Transvaginal, ultrasound-guided biopsy of the corpus luteum in cattle

摘要

An ultrasound-guided transvaginal technique for corpus luteum (CL) biopsy was developed and tested in cattle. The biopsy needle set consisted of an inner needle (o.d. 1 mm) with a 20-mm long specimen notch, an outer cannula (o.d. 1.2 mm) with a cutting edge, and an automated spring-loaded handle with trigger. The biopsy needle set was inserted into the channel guide of the handle of a convex-array transvaginal ultrasound probe. The transducer was positioned in the vaginal fornix, and the ovary wasmanipulated transrectally against the vaginal wall and transducer face. During monitoring on the ultrasound screen, the inner needle was pushed through the vaginal wall into the CL, and the cutting cannula was fired [released?], cutting and trapping luteal tissue in the specimen notch. Three luteal biopsies at each of 0 and 4 h were taken 10 days after ovulation in 6 heifers; 6 other heifers served as controls. A biopsy core was obtained in 36 of 39 attempts (92%). The tissue specimens seemed normal based on gross evaluation. The effect of biopsy on luteal function was assessed by daily ultrasound monitoring of luteal area, by assay of progesterone concentrations in blood samples obtained daily, and by the length of the interval from biopsy to ovulation. No significant differences were found for post-biopsy function for any of the 3 end points. It is concluded that repeated transvaginal, ultrasound-guided biopsy of the CL may be useful for experimental and diagnostic purposes in cattle.