|
|
 |
|
All early endoscopes
were rigid and used oil lamps as a light
source to illuminate the structure or organ
for viewing. Small electric filament bulbs
later replaced oil lamps.
Neither of these illumination methods was
satisfactory since the light produced was
very dim and generated a great deal of heat.
Fiber optics, the transmission of light
through flexible glass fibers, allowed the
illumination of internal structures with "cold
light," because the heat from the light
source is not transmitted through the length
of the endoscope. Fiber optic endoscopes
helped revolutionize surgery by requiring
only a tiny incision, or no incision at all,
thus greatly reducing recovery and hospital
time.
Rigid endoscopes were limited in their
usefulness since they created "blind
spots," or areas hidden from view due
to their inability to bend and conform to
internal structures. Dr. Harold Hopkins, a
physicist from Imperial College in London,
created the first "flexible fibrescope"
by assembling thousands of narrow flexible
glass fibers along which he conducted light.
He published his findings in January 1954.
Alterations and improvements of the early
flexible endoscope have greatly increased
light transmission capabilities, thus
allowing endoscopes to be thinner and
longer. The first laparoscopic
cholecystectomy was performed in 1983, and
computer chip cameras were attached to
endoscopes in 1990. |
|
 |
|
|
|
|
|
 |
|
 |
|
A rigid endoscope is a
non-flexible instrument made of surgical stainless
steel containing an optical lens train comprised of
precisely aligned glass lenses and spacers. |
| FOUR BASIC PARTS OF
THE RIGID ENDOSCOPE |
|
Objective
lens: The objective lens is located at the
distal tip of the rigid endoscope. It determines the
viewing angle - forward, oblique, lateral, or
retrograde. |
|
|
Telescope:
The optical element in a rigid endoscope is commonly
called a telescope. The telescope is the most
expensive and fragile part of the endoscope,
providing both the image and the light that allows
the image to be viewed. A fiber optic light cable
and power source transmit light through illumination
fibers distributed around the lens train. |
|
|
Light post:
The light post allows attachment of the light
cable to the telescope. |
|
|
Eyepiece:
The eyepiece, or ocular lens, remains outside of
the patient's body. The physician may either view
images directly, or attach a camera to the eyepiece
and view the images on a video monitor. |
| ANATOMY
OF A RIGID ENDOSCOPE |
|
The adaptability of the rigid
endoscope makes it a versatile tool with new
applications added constantly. |
 |
|
In the United States, over 10
million endoscopic procedures are performed each
year. These procedures are diagnostic, for
observation only, and operative. There are three
basic types of endoscopes: rigid, semi-rigid, and
flexible. Each type of endoscope is available with a
variety of diameters and lengths as well as channels
for irrigation, suction, and accessory instruments,
depending on the requirements of the procedure.
The flexible endoscope is used to view the interior
surfaces of the body's natural passageways such as
the gastrointestinal tract and the genitourinary
tract, conforming to the passageway's contours as
the scope is advanced. Flexible scopes can also be
used to view the interior surfaces of organs such as
the kidney, using these natural passageways as
access. Rigid and semi-rigid scopes can be passed
through natural passageways within the body and
incisions.
Rigid and semi-rigid endoscopes come in different
viewing angles: 120 or 110 retrograde, for viewing
backward; 90 and 70 for lateral viewing; 25, 30 and
45 of forward oblique views; and 0 and 12 for
forward viewing. The angle of the lens used is
determined by the position of the structure to be
viewed.
Flexible endoscopes are named based on the area of
the body they are designed to access. For example,
bronchoscopes access the bronchial area and lungs;
colonoscopes access the colon; gastroscopes access
the esophagus, stomach and duodenum; hysteroscopes
access the vagina and uterus; and ureteroscopes
access the ureters, bladders and kidneys.
The endoscope is a delicate instrument. Its care
and final reprocessing are vital, and repairs can be
costly. There is a substantial potential for the
transmission of infectious agents to patients
undergoing endoscopic procedures if reprocessing
protocols are not strictly followed.
Reprocessing (cleaning, disinfecting or
sterilizing) is a complex task because of the
endoscope's small joints, narrow lumens and fragile
components. It is extremely important to follow
precise mechanical cleaning to remove organic soil
from the endoscope, as subsequent steps in the
disinfection or sterilization will be ineffectual in
the presence of remaining bioburden. Failure to
remove the bioburden increases the potential for the
transmission of infectious agents to patients
undergoing endoscopic procedures. |
|
|
|
 |
