Endometrial cryoablation with ultrasound visualization in women undergoing hysterectomy

Study Objectives. To evaluate tissue effects of cryosurgical endometrial ablation in women just before hysterectomy, characterize ultrasound monitoring of freezing, determine the feasibility of a new probe-angling procedure, and assess the safety profile by monitoring serosal surface temperatures. Design. Single arm safety study enrolling ten women at two centers (Canadian Task Force classification II-2). Setting. Two clinical sites. Patients. Ten women scheduled for hysterectomy. Intervention. Hysterectomy with a new cryosurgical device (First Option, CryoGen, Inc., San Diego, CA) that achieves surface temperatures below -90 degrees C to freeze endometrium. Measurements and Main Results. The freeze protocol involved angling the probe toward each cornu. Maximum ice front diameter at the end of the first angled freeze ranged from 24 to 34 mm, and maximum ice ball diameter at the end of the second freeze ranged from 28 to 37 mm. The margin between the advancing ice front and serosal surface was monitored by ultrasound. In all cases the margin was safe and no reduction in serosal surface temperatures occurred. Depth of necrosis ranged from 9 to 12 mm as determined by tetrazolium staining and electron microscopy, and there was no hull-thickness myometrial destruction. Total endometrial destruction was achieved. Conclusion. Cryosurgical ablation of the endometrium with the First Option system with angled freezes and ultrasound monitoring appears to be feasible and safe given our preliminary data.