What does 'flexible' in flexible cystoscopy (CS) or flexible sigmoidoscopy (SIG) mean?

What "Flexible" Means in Flexible Cystoscopy and Flexible Sigmoidoscopy

"Flexible" refers to the physical property of the endoscope itself, which uses fiberoptic or video technology that allows the instrument to bend and navigate through curved anatomical structures, unlike rigid scopes which are straight and inflexible.

Flexible Cystoscopy

Flexible cystoscopy utilizes an endoscope with a bendable shaft that can be maneuvered through the urethra into the bladder with greater ease and less discomfort compared to rigid instruments.

Key characteristics:

• Physical properties: The scope is made with flexible fiberoptic technology that allows it to bend and navigate the natural curves of the urethra 1
• Patient positioning: Simplified positioning requirements compared to rigid cystoscopy 2
• Comfort: Causes less pain and is associated with fewer post-procedure symptoms than rigid cystoscopy 3
• Procedural advantages:
  • Reduced procedure time
  • Simplified preparation and draping of the patient
  • Can be performed under local anesthesia in an office setting 3

Diagnostic capabilities:

• At least equivalent diagnostic accuracy to rigid cystoscopy
• May be superior for visualizing certain areas like the anterior bladder neck 3
• Allows complete visualization of the bladder mucosa, urethra, and ureteral orifices 3

Flexible Sigmoidoscopy

Similarly, flexible sigmoidoscopy uses a bendable endoscope that can navigate the curves and angles of the sigmoid colon and rectum.

Key characteristics:

• Physical properties: Typically 60-70 cm in length with a flexible shaft that can bend to follow the natural curves of the bowel 3
• Insertion depth: Can reach much deeper into the colon (average 55 cm) compared to rigid sigmoidoscopy (average 20 cm) 4
• Patient comfort: Despite deeper insertion, patients generally report better tolerance compared to rigid sigmoidoscopy 4

Diagnostic advantages:

• Superior detection: Yields 2-3 times greater detection of colorectal neoplasms compared to rigid sigmoidoscopy 5
• Greater reach: Can examine approximately the lower third of the colon where about 60% of colorectal cancers occur 3
• Better visualization: Can navigate around strictures, angulations, or contracted lumens where rigid scopes would be unsuitable 5
• Improved diagnostic yield: One study found that 33.9% of patients with normal rigid sigmoidoscopy had significant lesions detected by flexible sigmoidoscopy, including malignancies 6

Clinical Implications

The flexibility of these instruments has significant clinical benefits:

1. Reduced discomfort: Patients experience less pain during the procedure
2. Improved diagnostic accuracy: Better visualization of anatomical structures
3. Broader applicability: Can be used in patients with anatomical variations or pathology that would prevent rigid scope use
4. Procedural versatility: Allows for therapeutic interventions like biopsies and polypectomies 6

Limitations

Despite advantages, flexible endoscopes have some limitations:

• Image quality may not be as sharp as rigid lens systems
• More difficult to use in patients with active bleeding
• Withdrawal of irrigant or drainage can be more cumbersome 2

The flexibility of these instruments represents a significant advancement in endoscopic technology that has improved both patient comfort and diagnostic capabilities in urological and colorectal examinations.