Prospective multicentre randomized controlled trial to evaluate factors influencing the success rate of office diagnostic hysteroscopy.

BACKGROUND Diagnostic hysteroscopy is not widely performed in the office setting, one of the reasons being the discomfort produced by the procedure. This randomized controlled trial was performed to evaluate the effects of instrument diameter, patient parity and surgeon experience on the pain suffered and success rate of the procedure. METHODS Patients were randomly assigned to undergo office diagnostic hysteroscopy either with 5.0 mm conventional instruments (n=240) or with 3.5 mm mini-instruments (n=240). Procedures were stratified according to patient parity and surgeon's previous experience. The pain experienced during the procedure (0-10), the quality of visualization of the uterine cavity (0-3) and the complications were recorded. The examination was considered successful when the pain score was <4, visualization score was >1 and no complication occurred. RESULTS Less pain, better visualization and higher success rates were observed with mini-hysteroscopy (P <0.0001, P <0.0001 and P <0.0001, respectively), in patients with vaginal deliveries (P <0.0001, P <0.0001 and P <0.0001, respectively) and in procedures performed by experienced surgeons (P=0.02, P=NS and P=NS, respectively). The effects of patient parity and surgeon experience were no longer important when mini-hysteroscopy was used. CONCLUSIONS Our data demonstrate the advantages of mini-hysteroscopy and the importance of patient parity and surgeon experience, suggesting that mini-hysteroscopy should always be used, especially for inexperienced surgeons and when difficult access to the uterine cavity is anticipated. They indicate that mini-hysteroscopy can be offered as a first line office diagnostic procedure.