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
HOT TOPICS
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).
HOT TOPICS
Reprinted with permission from the Healthcare Sterile Processing Association
48 PROCESS MARCH / APRIL 2024 www.myhspa.org
HOT TOPICS
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
HOT TOPICS
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.