A rigid cystoscope consists of a metal sheath, obturator, bridge, and telescope to which the light source is attached (Figure 4.1).The sheath has channels for irrigation fluid, and the bridge can have one or two working channels for insertion of instruments. Cystoscope sizes are given in French scale and refer to the outside diameter of the sheath in millimetres. (1 Fr = 0.3 mm, 15 Fr = 5 mm). The diameter of the sheath that is used commonly in adults is 17–24 French. In selected cases, a paediatric cystoscope may be needed (8 French).

Irrigation fluid in a cystoscope is usually sterile water or normal saline. If any electro‐coagulation is planned, electrolyte containing solutions must be avoided. Fluid distension in cystoscopy is gravity based with the fluid bag, placed minimum 80 cm above the patient position.

Different types of lenses are used in cystoscope and the operator chooses them according to the area to be visualised. A 0° or 12° lens is usually used for inspection of urethra, but are not particularly useful for visualisation of entire bladder. A 30° lens is useful in the visualisation of the posterior wall and base of the bladder and helpful in ureteric catheterization or stent insertion. A 70° or 120° lens helps in good visualisation of antero‐lateral aspect, dome of the bladder and in over elevated urethro‐vesical junction. Retrograde lenses with an angle of view of more than 90° can visualise the urethra and anterior bladder neck clearly.

Flexible cystoscopes have fibre optic bundles, telescope and irrigating channel combined into a single unit. The greatest advantage is the ability to visualise any aspect of the bladder and urethra, as the camera can be deflected from zero degree to 220°. The tip deflection can be on the same side as the lever deflection or on the opposite side from the lever deflection. The diameter of the flexible cystoscope is usually between 15 and 18 French (Figure 4.2).

Comparing the rigid and flexible cystoscopes, the rigid cystoscope has the advantage of better optics, larger lumen for irrigation, in turn giving better visualisation, larger working channels for instruments, and ease of manipulation and orientation. Rigid cystoscopy can be done under local anaesthesia, in the office set‐up when it is primarily diagnostic. With the larger diameter rigid scopes, the procedure can be done under general anaesthesia or IV sedation to reduce discomfort. The flexible cystoscope on the other hand, in view of its size, is more comfortable to patients and they are able to tolerate it with just local anaesthetic gel instillation. Flexible cystoscopes are more suitable to be done as an office procedure. In a flexible scope, with the deflection of the tip of the instrument, it is possible to visualise at any angle, the bladder neck, bladder wall, and urethra. Flexible cystoscopy, however, has a longer training curve compared to rigid cystoscopy.