To evaluate the effectiveness of a novel continuous irrigation sheath (NCIS) for improving the vision of a flexible cystoscope under gross hematuria and to investigate whether this NCIS increases patient discomfort.

A model was designed and a trial was conducted to quantitatively evaluate the effectiveness of the NCIS in vitro. The trial was divided into a static and a dynamic trial. The main difference between these two parts of the trial was the presence of continuous hemorrhage. There were 3 levels for the irrigation condition: no irrigation (group 1), continuous irrigation without an outflow of water (group 2), and continuous irrigation with an outflow of water (group 3). Flexible cystoscopy was conducted under different conditions and repeated, and the main outcome measures, including field of flexible cystoscope’s vision (FFCV) and definition of the pictures taken by the flexible cystoscope (DFC), were measured at 30, 60, 90 and 120 seconds. To investigate whether the NCIS increased patient discomfort, 36 patients were randomized into 2 groups to receive flexible cystoscopy with or without the NCIS.

Compared with groups 1 and 2, the FFCV and DFC values were significantly increased in group 3; however, the FFCV was not significantly increased compared with group 2 in the static model. The pain scores between patients who received flexible cystoscopy with or without the NCIS did not differ significantly.

The NCIS effectively improved the vision of a flexible cystoscope without increasing patient discomfort.