Transvaginal interstitial laser treatment of the ovary: a feasibility study in cows.

In 12 cows, transvaginal interstitial laser treatment (TILT) of the ovaries was performed using a neodynium:yttrium aluminium-garnet laser to investigate the feasibility of a new treatment approach for clomiphene-resistant patients with chronic hyperandrogenic anovulation. Powers of 1 and 2 W during 5 min of exposure were used. Sonographic changes of thermal damage during TILT, the extent and healing of the lesions by light microscopy and ultrasound during 3 month follow-up and adhesion formation were studied. During laser irradiation, a hyperechogenic zone developed around the fibre tip, with a mean +/- SD diameter of 4.4 +/- 2.0 mm at 1 W and 6.9 +/- 1.5 mm at 2. W. The mean diameters of the histological lesions 2 days after treatment were 7.3 +/- 2.5 mm at 1 W and 13.0 +/- 2.1 mm at 2 W. During follow-up, the mean diameter of both the histologically and the sonographically assessed lesions decreased, although transvaginal sonography (TVS) systematically and significantly underestimated the thermal damage. Lesions healed by fibrosis and no adhesions were present. TILT of the ovaries in cows is easy to perform and produces central or subcapsular necrosis without adhesions. TVS gives an indication of thermal damage but underestimates the extent of tissue damage in cow ovaries. Obviously, this study does not allow conclusions to be drawn concerning its safety and efficacy in man.