Brett S. Bowman

New transcervical sterilization procedure: optimal epithelial ablation

Objective: A novel transcervical method to achieve permanent fallopian tube occlusion has been developed. The Adiana procedure applies radio frequency (RF) energy to ablate the tubal epithelium and then deposits an ingrowable, synthetic implant into the lesion area of the fallopian tube. The quality of the ingrowth—and therefore the blockage of the tube—is hypothesized to be dependent on the character of the ablation. The objectives of this study are to test this hypothesis—and, if it is true, to determine the optimal ablation characteristics in a rabbit model. Methods: Forty-four New Zealand white rabbits were treated with the procedure, using various levels of RF energy. Temperature and time were used to control the intensity of the ablation, with a minimum ablation of 52°C for 60 seconds and a maximum ablation of 95°C for 60 seconds. The intensity was also quantified using an Arrhenius cellular damage score. Upon explant, histologic sections of the implant and surrounding tissue were taken and were analyzed using a qualitative ingrowth scoring system. Results: Ingrowth scores demonstrated a bell-shaped curve with respect to ablation intensity. Complete tubal occlusion occurred in ablations between 58°C and 70°C. Below this range the ingrowth was dominated by epithelial cells, whereas above this range the ingrowth was primarily necrotic; in both of these cases the tubal lumen was not completely blocked. Conclusion: The ability of the Adiana procedure to block the tubal lumen of the rabbit is dependent on the intensity of the ablation. The maximum ingrowth score occurred at moderate ablation parameters.