What Is the Best Lens Angle for Rigid Diagnostic Cystoscopy? A Comparison of 30-Degree and 70-Degree Lenses

The optimal degree of cystoscope to perform diagnostic cystoscopy is dependent on the surgeon's discretion because there are no studies addressing the superiority of one degree of cystoscope over another. The objective was to determine which lens, 70-degree versus 30-degree lens, was better in identifying lesions scattered throughout the bladder.

A simulation was created using 3 different artificial bladder models complete with sutures representing lesions placed at different locations in each bladder. Gynecologists and urologists performed cystoscopy using both the 30- and 70-degree lenses on the bladder models in a randomized and single-blinded fashion. The physicians performed routine diagnostic cystoscopy and noted the number of lesions throughout the bladder. The number of lesions each physician identified and the time to complete cystoscopy were noted. A total of 16 physicians participated, and there were a total of 18 lesions among the 3 different bladder models.

A total of 86 cystoscopy trials were obtained from all physicians and bladder models attempted. The odds of detecting a lesion with the 70-degree lens cystoscope was 1.77 times greater than the 30-degree lens cystoscope (95% confidence interval, 1.24-2.53; P = 0.002). There was also difference in the average number of lesions found between the 30- and 70-degree cystoscopes with 2.6 ± 2.7 more lesions identified using the 70-degree cystoscope compared with the 30-degree cystoscope. In terms of specific location, 2.6 ± 1.7 more lesions were found at the bladder neck using the 70-degree lens scope versus the 30-degree lens scope (95% confidence interval, 1.37-3.83; P = 0.013).

The results suggested that the 70-degree lens was the better choice for the identification of bladder lesions when compared with the 30-degree lens in rigid diagnostic cystoscopy.