TRANSVAGINAL OVUM PICK-UP (OPU) IN THE COW - A NEW DISPOSABLE NEEDLE GUIDANCE-SYSTEM

A study was conducted to modify the routinely used ovum pick up (OPU) devices to permit use of disposable needles and to simplify the techni que and to make it more economical and practical to use. Long nondispo sible needles are commonly used in transvaginal OPU despite several di sadvantages. A new OPU device was developed using 19-g disposable need les to eliminate these disadvantages and to make the technique more su ccessful. The disposable needle was connected to silicone tubing by me ans of a stainless steel connector. The system was inserted into a sta inless steel tube, creating a rigid structure within which to move the needle back and forth. A blunt needle can be changed simply by replac ing it with a new one, even while the device is in the vagina of a cow . The needle guidance system is incorporated into a new OPU device tog ether with the transducer of an ultrasonographic scanner with an unila teral orientated scanning field, making it possible to utilize the nee dle length to its maximum. This combination permits easy manipulation of the ovaries, easy positioning of follicles on the puncture line, an d enables the use of shorter needles which directly enter the scanned area without loss of useful needle length. As a preliminary result we obtained an overall oocyte recovery rate of 42%. Although this is prom ising, additional puncture sessions are needed to establish more consi stent recovery rates. When OPU is used routinely, application of short disposable needles is more practical and economical.