A BIPOLAR RADIOFREQUENCY CATHETER FAILS TO OCCLUDE A FELINE UTERINE HORN - A MODEL FOR FALLOPIAN-TUBE OCCLUSION

We developed a retrograde transvaginal-transcervical-transuterine ster ilization technique capable of ca using occlusive fibrosis and strictu re in the human fallopian tube. The procedure is required to induce a lesion at the intramural-isthmic portion of the tube at sufficient dep th to damage epithelium underlying the submucosa and inner muscular la yer, without acute damage to the outer muscular layer and serosal surf ace. Nineteen nulliparous purpose-bred cats were induced and maintaine d in an anestrus slate with testosterone cypionate 5 mg/kg intramuscul arly and a 6-18-hour light-dark cycle. After laparotomy, all animals h ad focal radiofrequency lesioning of uterine horns. Ten of 30 treated uterine horns appeared grossly occluded at the time of sacrifice; howe ver, histologic assessment demonstrated only 6 complete occlusions, an d 4 horns showed lack of complete lumen occlusion with or without evid ence of recanalization. Although no complications were encountered, bi polar radiofrequency failed to provide a consistent obstructive lesion in a tubular structure similar in size and morphology to the human fa llopian tube.