Karl Storz endoscope - Best practices

Endoscope selection and handling

Choose the smallest possible diameter endoscope that is compatible with the target anatomy (typically 1.9–3.0 mm for mice and rats).
Use rigid scopes for straight-line access (gastroscopy, laparoscopy) and fiberscopes for curved pathways (colon, trachea).
Always inspect optics and light cable before use for clarity, cleanliness, and alignment.

Autoclave or disinfect all reusable instruments; use sterile sheaths if necessary.
Prepare the surgical site using standard antiseptic techniques (iodine or chlorhexidine scrub).
Perform procedures in a dedicated clean workspace to minimize infection risk.

Use gentle insufflation (CO₂ via endo-arthroflator) for laparoscopy, keeping pressures appropriate for rodent physiology (commonly ≤5 mmHg in mice).
Avoid excessive suction or irrigation volume to prevent mucosal trauma.
Keep procedures short and efficient to reduce anesthetic burden.

Confirm animal eligibility: Use healthy, age- and weight-matched rodents; exclude animals showing signs of illness or stress.
Pre-anesthetic checks: Ensure hydration, record baseline weights, and apply ophthalmic ointment to protect corneas under anesthesia.
Fasting if applicable: For GI procedures, follow species-specific fasting guidelines to reduce stomach contents.
Use proper anesthesia and temperature control: Maintain stable anesthesia and prevent hypothermia with a regulated warming surface.

Select the correct endoscope type and size:
- Use rigid endoscopes (1.9–3.0 mm) for linear access (stomach, colon, abdominal cavity).
- Use fiberscopes or semi-flexible scopes for curved anatomical regions where maneuverability is essential.
Inspect optics before use: Ensure clarity of lenses or fiber bundles, and verify functionality of light and camera connections.
Sterilize all instruments: Autoclave rigid instruments or apply high-level disinfection for flexible scopes; use sterile drapes or sheaths as needed.
Test and calibrate auxiliary systems: Adjust the light source, camera focus, and insufflation or irrigation settings before beginning.

Stabilize the animal: Use a secure but gentle restraint method (surgical platform or padded holders) that avoids restricting respiration.
Insert scope gently:
- Lubricate the scope tip if necessary
- Advance slowly under visual guidance to avoid trauma or perforation

Use insufflation judiciously: For laparoscopy, maintain low intra-abdominal pressure (≤5 mmHg) to avoid vascular or respiratory compromise.

Control irrigation and suction: Use gentle, pulsed flushing to maintain visibility and avoid tissue injury.

Optimize image parameters:
- Adjust brightness, white balance, and zoom prior to insertion.
-Re-focus frequently, especially in curved or fluid-filled environments.
Preserve a clear field of view:
- Flush blood or debris intermittently.
- Use controlled suction to clear fluid without collapsing tissues.
Use working channels for precision:
- Introduce instruments (biopsy forceps, injection needles) slowly and under direct visualization.
- Monitor instrument path at all times to avoid off-target effects or damage.
Enhance image quality in fiberscopic systems:
- Apply honeycomb artifact suppression filters to reduce the characteristic grid pattern from discrete fiber elements.
- In live imaging, temporal or spatial averaging helps reduce noise while preserving resolution.
- When possible, select fiberscopes with high fiber count and well-aligned coherent bundles to minimize inherent artifact visibility.

Use appropriate filters and sources: Select far-red fluorophores compatible with the far-red channel (ICG) and match light intensity to imaging goals.
Prevent photobleaching: Minimize LED exposure time and intensity; capture essential data in brief, focused intervals.
Clean optics: Eliminate background fluorescence by ensuring lenses, scopes, and covers are free of residue.