Karl Storz endoscope - Best practices
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Endoscope selection and handling
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- 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.

Sterility and aseptic technique
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- 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.

Tissue protection and insufflation
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- 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.


Pre-procedural preparation
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- **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.

Instrumentation and setup
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- **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.

Animal positioning and scope insertion
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- **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.

Intervention and imaging
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- **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.

Fluorescence imaging (optional)
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- **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.