A cystoscopy is a medical procedure that allows a doctor to examine the inside of the bladder and the urethra. This examination uses a specialized instrument called a cystoscope. Patients often have questions about the size of the cystoscope, which houses a camera. This article clarifies aspects related to cystoscope size.
Understanding Cystoscope Sizes
Cystoscopes come in different forms, primarily categorized as flexible or rigid, each designed for specific purposes and patient anatomies. The camera and light source are integrated into the scope’s tip, allowing the physician to visualize the urinary tract. Instrument size is commonly measured in French (Fr) units, where one French unit equals approximately one-third of a millimeter. A higher French number indicates a larger diameter.
Flexible cystoscopes are pliable instruments that can bend and navigate the curves of the urethra. These scopes are generally smaller, typically ranging from about 15 to 18 French (approximately 5 to 6 mm). Their design allows for easier passage and can be used in an outpatient setting, often with local anesthesia.
Rigid cystoscopes are straight metal tubes that provide a direct, unobstructed view of the bladder. These scopes are generally larger, with common sizes ranging from 17 to 22 French (approximately 5.7 to 7.3 mm), and sometimes up to 24 French (8 mm) for specific procedures.
Factors Influencing Size Selection
The choice of cystoscope size is determined by several considerations. A primary factor is the patient’s individual anatomy, including gender and the natural diameter of their urethra. For instance, the female urethra is typically shorter and wider, which may allow for a broader range of scope sizes compared to the male urethra.
The specific purpose of the cystoscopy also plays a significant role. If the procedure is purely diagnostic, a smaller flexible scope may be sufficient. However, if the procedure involves therapeutic interventions, such as taking a biopsy, removing a bladder stone, or inserting a stent, a larger scope with an additional working channel may be necessary. These channels allow other instruments to pass through the cystoscope. The urologist’s experience and preference also guide the selection of the most appropriate cystoscope size.
How Size Relates to Patient Experience
The size and type of cystoscope directly influence a patient’s comfort and the need for anesthesia. Flexible cystoscopes, being smaller and more adaptable, are generally associated with less discomfort and can often be performed with only a topical anesthetic gel applied to the urethra. This allows many flexible cystoscopies to be conducted in an office setting, and patients can typically resume normal activities shortly afterward.
Rigid cystoscopes, while offering a clearer view, are larger and can be more uncomfortable, especially for male patients. For this reason, rigid cystoscopies are often performed under general anesthesia or deeper sedation. The choice between a flexible or rigid scope is carefully made by medical professionals.