Outpatient minihysteroscopy and conventional hysteroscopy: a comparative study

Objective: to compare the success of 3.5-mm minihysteroscopy to conventional 5-mm hysteroscopy as outpatient procedure.
Design: prospective non-blinded randomized study.
Setting: hysteroscopy unit in a university hospital
Materials and methods: seven hundred forty patients with different gynecologic problems referred for outpatient diagnostic hysteroscopy. Patients were randomized to 5-mm conventional (group I) or 3.5-mm minihysteroscopy (group II).
Main outcome measures: need for cervical dilatation, degree of pain, need for diazepam for sedation, occurrence of vasovagal attacks, duration of procedure and failure rate.
Results: cervical dilatation under local anesthesia was required in 27 (7.3%) and 5 (1.4%) patients of group I and II respectively (p < 0.001). Eighteen (4.9%) patients in group I experienced the procedure with almost no pain versus 82 (22.2%) patients in group II (p <0.001). Two hundred thirty eight (64.3%) patients experienced it as discomfort versus 261 (70.5%) patients in group II (p = 0.07). One hundred eight (29.2%) patients reported it as painful in the group I versus 25 (6.8%) in the group II (p < 0.001). Six (1.6%) in the group I experienced it as very painful versus 2 (0.5%) patients in group II (p = 0.28). Diazepam was required in 10 (2.7%) and 1 (0.3%) patients of group I and II respectively (p = 0.006). Vasovgal attack was observed in 5 (1.4%) and 1 (0.3%) patients of group I and II respectively (p = 0.2). Mean time of the hysteroscopy was significantly shorter in group II than that of group I (84±5 versus 155±9 seconds, p < 0.001). Failure of the procedure occurred in 17 (4.6%) and 10 (2.7%) patients in group I and II respectively (p = 0.16).
Conclusion: Outpatient 3.5-mm minihysteroscopy is more successful than 5-mm conventional one. It is less painful and can be conducted in shorter time. It is safe procedure with low failure rate.