Assessment of the safety of intrauterine instillation of heated saline for endometrial ablation.
OBJECTIVE: To evaluate the safety of pressure, temperature-controlled, continuously circulating hot saline (EnAbl system, InnerDyne Medical, Sunnyvale, CA) for endometrial ablation using the in vivo human uterus. DESIGN: Clinical safety study. SETTING: An academic research environment. PATIENTS: Eleven women undergoing abdominal hysterectomy because of abnormal uterine bleeding. INTERVENTION: Before uterine removal, endometrial cavities were exposed to 15 minutes of recirculatory normal saline heated to 70-85 degrees C. MAIN OUTCOME MEASURE(S): The uteri were analyzed for extent of thermal damage using standard histopathological techniques and tissue viability histochemical staining. Intrauterine pressures and serosal and subserosal temperatures were continuously monitored by computer. RESULT(S): In each treated specimen, histochemical staining demonstrated a depth of necrosis that extended through the entire endometrium and approximately 1-2 mm into the myometrium. The control specimen showed no thermal or mechanical damage. There were no observed negative effects or related complications with this system. CONCLUSION(S): The computer-controlled system employing continuously circulating hot saline is an effective method to destroy the endometrium. In four cases with clearly patent tubes, no spill was observed. In all 11 patients, serosal and subserosal temperatures were within safe levels (mean temperature, 37 degrees C).