Rigid Endoscope Risks

Rigid endoscopes have been a source of concern when it comes to the protection and inspection of these delicate and frequently used devices. Damage of rigid arthroscopes may have been blamed on the handling of the sterile processing professional during the processing, but there are other contributing factors based on a recent study that may be overlooked like having the correct inspection tools to effectively evaluate the integrity of the inner optics and outer distal window lens.

Evaluation of Internal Optics and Exterior Window Lens Integrity for Rigid Endoscopes

BY CHERON ROJO, BS, CFER, CRCST, CHL, CIS, CER, FCS

SENIOR CLINICAL EDUCATION SPECIALIST—HEALTHMARK INDUSTRIES

46 PROCESS MARCH / APRIL 2024 www.myhspa.org

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Reprinted with permission from the Healthcare Sterile Processing Association

www.myhspa.org MARCH / APRIL 2024 PROCESS 47

Abstract

Failures of the internal optics and exterior window lens

of a rigid endoscope can negatively impact patient safety.

The purpose of this study was to identify the frequency of

integrity failures for the internal optics and distal exterior

window lens for a variety of rigid endoscopes with the use

of an endoscopic video verification tool and an enhanced

inspection microscope. During a 12-month study, 29 facilities

were examined across five states. Forty-one rigid endoscopes

were tested for integrity of internal optics and examined for

damage to the exterior distal window lens.

For the study, the U.S. Food and Drug Administration’s

(FDA’s) Manufacturer and User Facility Device Experience

(MAUDE) database was also searched for documented adverse

events of failures with rigid endoscopes’ internal optics and

exterior window lenses, and the findings were reported. The

conclusion is that integrity failures emphasize the need for a

proactive approach to using inspection verification tools to

identify failures within rigid endoscope optics and exterior

distal window lenses to ensure better patient outcomes.

Background

Integrity verification inspection during rigid endoscope

processing is a vital step performed in the Sterile Processing

(SP) area. Rigid endoscopes are the primary visualization

device in laparoscopic procedures, and their diverse lengths

and diameters allow them to be used across a multitude of

service lines. Inspection verification commonly involves

standard magnification for viewing from the proximal eye

piece, subjectively identifying abnormalities, and holding

the rigid endoscope to the light to identify damaged light

fibers (visualized as black dots). Exterior inspection of the

rigid endoscope’s distal window lens tip has historically been

performed either with a tactile approach or the use of a cotton

ball, which only identifies metal burrs around the parameter

of the window lens and does not identify other possible

integrity failures.

Damage to the internal optics within a rigid endoscope

can impede the surgeon’s vision, negatively affecting the

procedure’s accuracy and outcome. Defects to the exterior

window lens can tear internal patient tissue, and debris

from the damaged lens (e.g., metal shavings, glass fibers and

bioburden) can fall into the patient’s sterile cavity and cause

significant patient risk.

This study reinforces the need for adequate surface-

enhanced magnification and internal endoscopic video

verification tools.

Adverse Events: FDA MAUDE Database Reports

As background for the study, a search of the FDA MAUDE

database was conducted. A significant number of adverse

events were found that identified rigid endoscopes with

integrity failures of the internal optics or exterior window

lens. Some more recent examples of similar adverse events

include:

• October 15, 2023: It was reported that the laparoscope lens

seemed to be loose due to an internal failure; it would come

in and out of focus and was discovered during an arthroscopy

procedure with no patient harm.1

• August 9, 2023: It was reported that a 2.3 mm x 72 mm

arthroscope had “a dark image during the procedure.”2

• May 16, 2023: It was reported that the scope overheated,

injuring the patient with what appeared to be a thermal, first-

degree burn. The telescope had gouging around the distal

end, with a chipped-rod lens.3

• May 3, 2023: A blurry image during the procedure was

reported.4

Methods

The study was conducted using an endoscopic video

verification tool. This tool has the ability to capture images

and videos with the use of a portable mini video tower and a

test card pattern (known as USAF-1951) to identify integrity

failures of the internal optics within a rigid endoscope. An

enhanced magnification microscope was utilized to identify

abnormalities on and around the external distal window lens

of the rigid endoscope.

Results

The 12-month study was conducted from May 2021 to

May 2022 at 29 healthcare facilities. Of the 41 total rigid

endoscopes tested, five exhibited integrity failures of the

internal optics (12.20% fail rate). See Figure 1. The study also

identified the external distal window lens had the highest

failure rate (63.41%); of the 41 examined, 26 demonstrated

integrity failures (see Figure 2).

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Reprinted with permission from the Healthcare Sterile Processing Association

48 PROCESS MARCH / APRIL 2024 www.myhspa.org

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The results (illustrated in Figures 1 and 2) revealed there

were several contributing factors for unnoticeable integrity

failures:

• Lack of verification tools to clearly identify integrity failures

of the internal optics within the rigid endoscope effectively

(see Figures 3 and 4).

• Deficient magnification to identify abnormalities around and

on the external surface (e.g., standard desktop magnification

ranges between 1.8x and 2.0x). To clearly identify damage,

an enhanced microscope of 10x to 240x magnification level

should be used. (See Figure 5).

• Inadequate education for technicians to identify damage (e.g.,

blurred or foggy lenses, metal burrs, and dents at the distal

end). The focus of inspection was primarily the eye piece at

the proximal end and medial area of the shaft. See Figure 6.

Figure 1: Internal optics integrity

failures

Figure 2: External distal window lens

integrity failures

Figure 3: Endoscopic video verification tool with identified damage (broken

glass rod within the rigid endoscope)

Figure 5: Enhanced magnification microscope and identified damage (exposed

glass light fibers)

Figure 6: Identified with the use of an enhanced magnification microscope

(exposed burrs, gouges, recessed areas, and scratches)

Figure 4: Endoscopic video verification tool with identified damage (dislodged

lens within the rigid endoscope)

Reprinted with permission from the Healthcare Sterile Processing Association

www.myhspa.org MARCH / APRIL 2024 PROCESS 49

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It was concluded that the integrity failures emphasize the

need for a proactive approach to inspection verification tools

to identify failures within rigid endoscope optics and exterior

distal window lens for better patient outcomes.

Applicable Recommendations and Standards

for Inspection

Currently, the newer section of ANSI/AAMI ST79:2017

Comprehensive guide to steam sterilization and sterility assurance

in health care facilities,states that “Each time a medical device

is processed, it should be visually inspected for cleanliness and

integrity. Enhanced inspection with magnification, borescopes,

or other inspection methods to verify cleanliness and integrity

may be used.”5

This section also states that “Health care

facilities should have a method of ensuring the cleanliness

and integrity of every instrument and medical device used in

every procedure.”5 Lastly, it notes that “Damaged instruments

or incomplete instrument sets/trays may cause a delay or

cancellation of a surgical procedure and/or increase risk of

patient harm related to instrument malfunction.”5

The Healthcare Sterile Processing Association’s Sterile

Processing Technical Manual, ninth edition, states that

“Functions, such as light output, image quality, should be

examined.”6

The resource also notes that “for non-video rigid

endoscopes, the image quality should be tested by viewing

typewritten print through the endoscope from a distance of

about one inch. The image should be closely examined in the

center and for 360 degrees around the outside edge to ensure

there are no blurry or dark areas.”6

Limitations

The sample size of the study was affected by the number of

rigid endoscopes a facility could release for examination

as well as inconsistencies with the type of rigid endoscope

inspected. The study’s focus was only on inspection and

verification tools (no other areas of concern in the total

processing of the devices).

Conclusion

The study determined several contributing factors in the

internal and external inspection process for rigid endoscopes.

These integrity failures underscore the significance of

appropriate use of verification tools and proper education

(initial and continuous) for the inspection process. Together,

tools and education help maintain instrument longevity and

lower repair and replacement costs, while also decreasing

adverse patient events.

REFERENCES

1. U.S. Food and Drug Administration (FDA). Manufacturer and

User Facility Device Experience (MAUDE). October 16, 2023.

www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/search.cfm

2. FDA. MAUDE. August 9, 2023. www.accessdata.fda.gov/scripts/cdrh/

cfdocs/cfmaude/search.cfm

3. FDA. MAUDE. May 16, 2023. www.accessdata.fda.gov/scripts/cdrh/

cfdocs/cfmaude/search.cfm

4. FDA. MAUDE. May 3, 2023. www.accessdata.fda.gov/scripts/cdrh/

cfdocs/cfmaude/search.cfm

5. Association for the Advancement of Medical Instrumentation. ANSI/

AAMI ST79:2017 Comprehensive guide to steam sterilization and

sterility assurance in health care facilities [8.2.1], Amendment A.2.

2020.

6. HSPA. Sterile Processing Technical Manual, ninth ed., pp. 174–178.

2023.

Disclaimer: The views and opinions expressed in this column are those of the

author and do not necessarily reflect the views of HSPA. The content provided

in this column is also not a reflection or representation of any other company or

organization with which the author may be affiliated.