In vitro occlusion of human fallopian tubes with Nd:YAG laser

There is a need for an atraumatic, fast, reliable, inexpensive, reversible-on-demand method for female sterilization which is also free from side-effects. The use of an Nd:YAG laser for occlusion of human fallopian tubes in vitro was assessed for achieving these aims.

An in vitro study was performed on coagulation of fallopian tube tissue using continuous wave Nd:YAG laser. Posthysterectomy human uteri were exposed to laser radiation either directly through an optical fibre or through a sapphire contact probe at the ostia at different laser powers and inter-action times.

Laser-induced tissue coagulation plugged the ostia in a clean, controlled and predictable manner. Microscopic examination of the coagulated tissue showed about 50 microns wide blind holes without any continuous channel; thus eliminating the possibility of passage of sperms through such a plug. The depth of coagulation along the lumen of the fallopian tubes increased linearly with the interaction time of the laser beam at a constant power, either by direct irradiation or through a contact probe. The maximum depth of coagulation was found to be about 3 mm in case of direct irradiation at a laser power of about 6.5 W and interaction time of 50 seconds. Beyond these values, charring occurred at the surface of the tissue.

Nd:YAG laser might be a suitable means for female sterilization. Further studies in experimental and clinical settings would be required to confirm its utility.