Control of intrauterine fluid pressure during operative hysteroscopy.

Study Objective: To evaluate the safety of a commonly used piston pump that controls the infusion pressure of low-viscosity fluids in a continuous-flow hysteroscopic system during operative hysteroscopy.

Design: Consecutive patients requiring operative hysteroscopy.

Setting: Three hospital facilities in the Midwest.

Patients: Sequential sample of 250 women who underwent operative hysteroscopy.

Interventions: Endometrial ablations, resection of submucosal or pedunculated uterine leiomyomata with or without endometrial ablation, polyp resections, metroplasty, and lysis of synechiae.

Measurements And Main Results: The most serious complication of operative hysteroscopy is fluid overload due to intravasation into the patient's vascular system. Low-viscosity fluids were infused by the Zimmer Controlled Distention Irrigation System. The instrument uses a closed-feedback loop to monitor cavity pressure and automatically regulates the flow to maintain the set point pressure. It is designed to operate in a pressure range of 0 to 80 mm Hg and at flows in excess of 450 ml/minute. In 250 operative hysteroscopies no fluid complications occurred when intrauterine pressure was maintained below 80 mm Hg. No clinically significant differences in intravasation were seen in any type of operative hysteroscopy.

Conclusions: This controlled mechanical pump system with exact intrauterine pressure measurement reduced many technical difficulties associated with low-viscosity media, and created a safe environment for the media's use in operative hysteroscopy.