Study objective: Our objective was to compare intrauterine pressures during resection and aspiration modes among three types of commercially-available hysteroscopic morcellators.
Design: This was a benchtop study (Canadian Task Force level II-1). This study cannot feasibly and ethically be done in-vivo, so an ex-vivo study design was chosen.
Setting: A silicone uterine model was attached to a manometer via tubing, with the tip inside the cavity to allow for intracavity pressure measurements. Each hysteroscopic morcellator was then introduced, and intracavity pressures were recorded every one to two seconds in three modes (static, resection, and aspiration) and at three set point pressures (45, 85, and 125 mmHg).
Patients: No human subjects were involved in this study.
Measurements and main results: There were a total of 4,872 pressure measurements during this study across the three devices, over the three modes, and at the three set point pressures combined. Using mixed-effects linear regression, the mean observed intracavity pressure was not greater than the set pressure for each of the three devices. This result held true in both aspiration and resection modes. In our statistical models, the coefficient on the terms representing the interaction between device and time were not statistically significant in either resection or aspiration modes. This indicates that, statistically, the change in intracavity pressure over time was not significantly different across the three devices.
Conclusion: In this first of its kind head-to-head benchtop study, we found that all three commercially-available hysteroscopic morcellators appear to be similar to each other in terms of their abilities to maintain intracavity pressure below the set pressure, which is important in avoiding intravasation in-vivo. These findings are important because many gynecologists do not have the ability to choose between the three available devices on the market at their institution.