Comprehensive Study Guide to Rigid and Semi-Rigid Endoscopy pt 2

Overview and Definition of Endoscopy

• Meaning of Endoscopy: The term "endoscopy" literally translates to "looking inside." It refers to medical procedures that allow a physician to examine the interior of the body using a specialized instrument known as an endoscope.

• Definition of Endoscope: An instrument used to examine the interior of a hollow organ or body cavity.

• Minimally-Invasive Nature: Endoscopic procedures are considered minimally invasive because they do not require large incisions. Instruments are inserted either through natural body orifices (such as the mouth, nose, or anus) or through very small incisions made to provide access.

• Broad Utility: These instruments allow for the visualization of specific body areas and, when used with other instruments, can be utilized to perform various types of surgeries.

Historical Development and Evolution

• Origins: The first endoscopes were developed in Germany during the 1800s.

• Modern Expansion: The use and technological development of endoscopes saw a significant increase in popularity following World War II.

• Flexible Technology: The flexible endoscope was introduced in the 1950s.

• Advancements in Size: Technological progress has led to the creation of smaller instruments and endoscopes, fueling advancements across various surgical specialties.

• Expanded Clinical Capabilities: Examples of modern endoscopic capabilities include:

  • Treating heart conditions without opening the chest or cutting the ribs.

  • Performing pituitary surgery through the sinus cavity.

  • Removing salivary gland stones.

  • Directly visualizing lesions in the gastrointestinal tract and lungs.

  • Performing diagnostic biopsies and therapeutic procedures without major surgery or general anesthesia.

Endoscope Classification and Selection

• Classification Criteria: Endoscopes are classified based on their function, care and handling processes, and specifically their ability to bend without sustaining damage.

• Rigid Endoscopes:

  • These are used when there is straight-line access to the surgical site.

  • General rule: A rigid endoscope should never be bent.

  • Construction: Usually made of stainless steel. They allow for minimal flexing of the shaft, but damage occurs if they are pushed beyond their flex limits.

  • Size Range: They vary from very tiny ($1.9\,mm$ endoscopes used for sialendoscopy/salivary gland viewing) to larger ($15\,mm$ endoscopes used for robotic surgical procedures).

• Semi-Rigid Endoscopes:

  • Used primarily in urology to view the bladder and the distal portion of the ureter.

  • The shaft is made of very thin stainless steel, which allows it to bend slightly without kinking the metal.

  • These are used when the trajectory to the surgical site is relatively straight but requires a slight bend to access certain anatomy, such as in bladder surgery.

  • Limitations: While they bend more than rigid scopes, they will be damaged if too much pressure is applied or if bent beyond intended limits.

• Flexible Endoscopes:

  • Utilized when straight-line access is impossible, such as when viewing the lungs, kidneys, or large intestine.

• Selection Process: The physician chooses the endoscope based on the specific type of procedure being performed.

Operative vs. Non-Operative Endoscopes

• Non-Operative Endoscopes: These were the earliest types of endoscopes. They allow a surgeon to view anatomy but do not have the capability to perform surgical procedures like biopsies.

• Operative Endoscopes: These contain a working channel (lumen). This channel allows the surgeon to pass instruments or accessories through the scope to perform corrective or diagnostic surgical procedures (e.g., laparoscopy, arthroscopy).

• Benefits of Operative Endoscopy: These instruments lead to shorter hospitalizations, less painful procedures, lower risks of Healthcare-Associated Infections (HAI), and faster patient recovery times.

Anatomy and Construction of Rigid Telescopes

• Optical (Lens) Train: The internal components of a rigid endoscope include:

  • Distal Lens

  • Objective Assembly

  • Rod Lens (Rigid rod lens train)

  • Inner Tube

  • Spacer

  • Ocular Assembly/Eyepiece

• Outer Structure:

  • Outer Tube

  • Light Post

  • Light Guide Post (where the external light source attaches)

• Field and Angle of View:

  • Angle of View Block

  • Field of View

• Internal Housing: Fiber optics are housed between the inner and outer tubes. They transmit light from the light guidepost to the distal end ($tip$) of the endoscope.

• Video Integration: Some rigid endoscopes are constructed with a video chip mounted in the distal end (video scopes), while others use traditional lenses (non-video).

Optics and Illumination Systems

• Image Transmission: Endoscopes transmit reflected images back to the surgeon’s eye or a video system. This is achieved via fiber optic bundles or computer chips inside the device.

• Light Sources:

  • Light-Emitting Diodes (LED): Semiconductors that emit light when voltage is applied. They act as tiny light bulbs.

  • Fiber Optics: These do not produce light themselves but act as "wires" (glass or plastic strands) to carry light from an external source to the distal end.

• Impact of Light Quality: The quality and quantity of light are critical factors; the clarity of the image is largely dependent on them.

• Fiber Damage Identification: To ensure working order, endoscopes and light carriers (fiber optic cords) must be checked during processing. Dark areas in the fiber bundle indicate damaged light fibers.

Specialty Rigid Endoscopes

• Variable Direction of View: Some specialty endoscopes allow the surgeon to change the direction of view by rotating a knob near the eyepiece. These feature a variable direction of view lens system at the distal tip.

• Filtering Endoscopes: Certain scopes contain filters that help identify diseased tissue when used in conjunction with pharmaceuticals and/or specific spectrum light sources.

General Decontamination and Cleaning Guidelines

1. Adapter Removal: Remove light source adapters from the light post before cleaning.

2. Cleaning Solution: Use only the cleaning solution identified in the manufacturer's Instructions for Use (IFU).

3. Hand Washing: Use a soft, non-linting cloth. Pay particular attention to the distal tip, where debris often collects and is most difficult to remove.

4. Brushing: If the endoscope has a working channel, brush it thoroughly using the manufacturer's recommended brush type and size.

5. Rinsing: Thoroughly rinse with critical water and flush the working channel to remove all cleaning solution traces.

6. Drying: Dry the outside with a clean, non-linting cloth. Dry the working channel according to the manufacturer's IFU.

• Automated Washing:

  • New technology allows for automated washing of non-operative rigid endoscopes.

  • The technician must verify that the specific tray and endoscope are approved for automated washing per the IFU.

  • Benefit: Provides consistent quality in the wash process.

  • Warning: Ultrasonic cleaning cycles must not be used with rigid endoscopes during automated washing, as damage will occur.

Inspection and Functional Testing

• Basic Guidelines: Follow the manufacturer's IFU for all inspection steps. Closely inspect for both damage and cleanliness.

• Functional Verification: Examine functions such as light output, image quality, and angulations (if applicable).

• Component Fit: For rigid endoscopes used with bridges or sheaths, ensure the devices fit together with little to no force.

• Window Maintenance: Inspect distal and proximal windows for cleanliness. Wipe with an approved cleaner and soft cloth if needed.

• Image Quality Test (Non-Video Scopes):

  • View typewritten print through the endoscope from a distance of about one inch ($1\,inch$).

  • Examine the image in the center and for $360^{\circ}$ around the outside edge.

  • Look for blurriness or dark areas.

  • Note: Most flexible fiber optic endoscopes have a focus-adjusting mechanism near the eyepiece.

• Rigid Endoscopic Instruments: These come in hundreds of shapes and sizes. Many contain lumens that require specialized cleaning. Devices that can be easily disassembled help technicians determine the effectiveness of the cleaning process.

Maintenance of Powered Surgical Equipment

• Importance of Care: Powered surgical equipment is expensive and delicate. Proper handling and preventive maintenance are essential for safety and effectiveness.

• Common Causes of Damage:

  • Corrosion of internal components due to steam, fluid invasion, or improper cleaning.

  • Physical damage from mishandling.

  • Lack of or improper preventive maintenance.

• Pre-Sterilization Steps:

  • Lubrication: Lubricate according to the device's IFU (note that not all instruments require lubrication).

  • Function Testing: Some manufacturers recommend operating handpieces to ensure function and disperse lubrication before packaging.

  • Accessory Check: Attach batteries and accessories to ensure proper fit.

• Sterilization and Packaging:

  • Package per manufacturer recommendations. Some packaging (like peel packs) may not be suitable for all powered instruments.

  • Use special racks or positioning devices to ensure sterilant exposure and prevent condensation collection.

  • Batteries: Charge, package, and sterilize batteries per the IFU. Document the charging date on the outside of the package.

General Precautions

• Delicate Nature: Endoscopes are at risk of damage every time they are handled due to their delicate construction and frequent use.

• Consequences of Damage: Damaged endoscopes result in procedure delays, surgeon dissatisfaction, and potential patient harm.