A new instrument: a flexible hysteroscope with narrow band imaging system: optical quality comparison between a flexible and a rigid hysteroscope.

There are two different types of hysterocopes available: Flexible and rigid. Flexible scopes have the ability to observe the whole intrauterine cavity, but it is difficult to perform an operation on endometrial lesions. Rigid hysteroscopes provide superior optical qualities due to higher pixel count. We report the use of a new flexible hysteroscope with narrow band imaging (NBI) system (HYF-V EndoEYE Flexible Video Hysteroscope) and compared the optical qualities of this flexible to those of a rigid hysteroscope using the vascular analysis software "SolemioENDO ProStudy". Twenty-four images of endometrium in eight cases, and 12 images of submucous myoma in six cases were each photographed by two the hysteroscopes. The vascular densities of both endometrium and myoma under conventional light in the flexible scope were significantly higher than with the rigid scope. However the vascular densities under narrow-band light in the two scopes were not significantly different. The vascular densities of the images taken by flexible scope were higher than the images taken by rigid scopes under conventional light. With the rigid scope, microvascular structure may be crumpled by high water pressure. A flexible hysteroscope with NBI system has superior ability to observe the intrauterine cavity and measure vascular density compared to a rigid scope.