Adequacy of ovarian diathermy under ultrasound control: an experimental model

To develop a minimally invasive ovarian cauterization technique under transvaginal ultrasound control and evaluate the safety and feasability of monopolar cauterization to cause ovarian injury using female cattle of reproductive age as an experimental model.

Experimental study in a university research center was performed. Eleven female bovines of reproductive age were submitted to monopolar transvaginal ovarian cauterization. The right ovary (RO) was punctured at four sites and 40 W was applied for 5 s at each point, resulting in a total of 800 J (Joules) of thermal energy. In the left ovary (LO), the procedure was similar, with the same time and 80 W, resulting in a thermal energy of 1600 J. Macroscopic and microscopic lesions were assessed.

Of 22 ovaries punctured, 20 were cauterized and exhibited macroscopic and typical microscopic lesions. No lesions could be found in the needle path. The measures of the areas of microscopic electrocautery lesions calculated estimating a cylindrical volume showed a median of 1.12% in the right ovary and 1.65% in the left ovary. When the estimate was calculated by spherical shape, the medians were 1.77% in the right ovary and 3.06% in the left ovary. There was a statistically significant difference in these two estimates (sphere, p = 0.008; cylinder, p = 0.021).

The experimental animal model described for transvaginal ultrasound-guided ovarian needle cauterization seems to be feasible. The ovaries were successfully cauterized without injuries in needle path and more energy resulted in significantly more thermal lesion. The safety and effectiveness of this technique, theoretically less invasive than current ovarian drilling methods, could be tested in anovulatory women with PCOS.