The topic is not as perplexing as it is thought to be. An average doctor
easily gets confused with Oesophagoscopy, Gastroscopy, OGD, Endoscopy,
Colonoscopy, Laparoscopy, Peritineoscopy, culdoscopy ,sinuscopy and
many other. His source of information is the prescription of consultants.
Consultants take as fancy to write the words according to their taste.
May be, for practical purpose requesting for Gastroscopy and OGD (Oesophago
Gastro Duodenoscopy) , is the same, because the G.I. Endoscopist is
going to see right up to the Duodenum as such, but it is enough to confuse
this doctor, who is gaining knowledge only by the prescriptions of the
higher consultants. When I was requesting doctors to send their patients
of dyspepsia and ulcerations to me for upper G.I.Scopy, some of them
used to ask about the feasibility for the abdominal surgery with the
We have been curious to know the inside of our body since ages. To
know about the functioning and malfunctioning i.e the physiology and
the pathology. Radiodiagnosis is an indirect vision, i.e a sort of assessing
a thing by means of it's shadow.
Endo means inside and scopy means visualization. It is to see the inside
of the body.
You can enter the body through the natural orifices.
Through mouth to access the upper gastrointestinal tract i.e. esophagus
(food pipe),stomach (the collection centre for food) and duodenum (the
beginning of the small intestine), this is called as Oesophago-Gastro-Duodenoscopy
( OGD), now with the slender scopes we can move still farther and have
a look inside the small intestine, called as Saude scopy.
Through anus in to the colon (large intestine, upto the junction of
small and large intestine) called as Colonoscopy. If you go only in
the sigmoid with a rigid scope, it is called as a sigmoidoscopy.
Though trachea (wind pipe), called Bronchoscopy.
Through nose, into the cavity of sinuses (hollow regions in the skull),
called as a sinuscopy.) In to the ear, auroscopy.
In short now it is possible to enter all natural orifices.
For precise visualization, you need light and magnification both. The
advancement of optics has solved both the problems. It was easy to enter
a cavity or a lumen which is straight. The magnification was achieved
by putting in the series of lenses called the rod lens system. Good
illumination was made possible by xenon bulbs, which emitted light as
good as day light. We could see precisely the straight viscous like
esophagus and a part of stomach, sigmoid, with little manipulation,
Bronchus till the bifurcation and the sinuses. The inability to see
the bowel or bronchus beyond the curves did not become possible till
after the advent of fibre optics. The advent of fiber optics was for
the telecommunication and other purposes, from which we derived our
A glass rod cannot be bent like a steel rod but if you make it more
and more thin, like a wire, bending could be achieved in a glass rod
also, as it was very thin, we named it a fiber. These glass fibers we
see very often in the shape of glass wool. The usual diameter of the
glass fiber of this type, used in the scope is 2 to 3 mu. (about 1/3rd
of the thickness of the hair). These glass fibers were coated from out
side, the light could be transmitted from one end to the other on the
principle of total internal reflection. These glass fibers were tied
up in the form of a bunch, and bending of that bunch was possible. You
can bend a seenk jhadu but cannot bend a wooden log of the same diameter.
The intense light could be transmitted through these fibres from one
end to the other. Heat of the light source remained at this end and
only light was carried out at the other end. This is called as the cold
light. Previously all the scopes had the glowing bulb at it's terminal
end, more the intense light more heated was the bulb, making the vital
structures susceptible for thermal injury. With the colder bulb, since
it was of less wattage, the light was also poor. You had to choose between
the light or the safety, we needed both! At the end of that fiber glass
bundle a lens could be attached for the magnification. But you got to
have an image or in other words what is the use of a lense if you don't
have any thing to see. The practical problem with the image was, if
you send image of an object, like image of the inner of the intestine,
through on end of this bunch of the glass fibers, since each fiber carried
a part of the image, the total number of fibre is in millions, the image
that will be carried to our eyes thorough this bunch of glass fibers
was you can imagine how much haphazard, if it is split into millions
without any sequence in it.
One can imagine in an easier way, if we tear our own photograph in
even 8 or 10 pieces and stick it in a haphazard pattern, we will not
be able to recognize our own face. One thing was encouraging; we could
now take the light and image from one place to the other with a glass
fiber, even when the path was not straight. Till the image could be
seen, there was no use throwing light there. To transmit the image as
such it was necessary to align the fiber bundles precisely, i.e. the
position of the bundle at both the ends of the scope should be the same.
The fiber starting at the 12 O clock position should end at the 12 O
clock position. If it is at the centre in the beginning, it should end
at the centre terminally. Then only we expect to see the image at the
other end. It was very difficult to achieve because how can you precisely
place the million fibers at the same position 1 1/2 meters away. It
was not possible to make two different sieves with so thin pores a million
in an area of 9.8 mm dia, and match both the holes, and then place the
fiber between them, and then take out both the sieves, doing all this
without breaking the fibers. It was just impossible to do it in that
way. A genius came up with a very simple idea, on which today the scope
is manufactured. The fiber bundle is wound over a large drum. At a point
an area is glued and they are cut in between. Now since before cutting
the fiber was the same, it had to be at the same position, when the
bunch became straight and fell off the drum after this chop. Lenses
were fit on both the ends, i.e the eye piece and the terminal end. The
idea was fantastic, like a safety pin look so simple but hats off to
the brain who made it. So we now had a fiber bundle that could transmit
image. This perfect alignment is called as coherence and the image bundles
are coherent. Light bundles need not be so. Both the bundles , along
with a hollow channel (called as working channel) for suction and doing
therapeutic procedures like injections or doing a biopsy, and a channel
to throw water on the lens with a portion of it for air insuflation
of the gut, all these were wrapped in a flexible steel sheath, having
multiple joints. Bending was made possible by incorporating steel wires
in this steel sheath, wound over the wheel above. With rotation of the
wheel, the wire of one side got taught and of the other side got relaxed
and lengthened, there by bending the tip of the scope. This is just
like you bend the fingers by contraction of the forearm muscles and
tightening the ligaments of your hand. All this was wrapped by the PVC
to protect it from water and to make it smooth so as to make it possible
to insert in without causing discomfort and injury.
This is the story of making of a scope.
Endoscopy is a branch that deals with the visualization of the interior,
and treatment also at times, obviating the need for a major operation
otherwise. The best example is that of jaundice. If the biliary tree
is obstructed due to a stone, we can go through the upper gastrointestinal
scope up to that area, take out the stone, cut the constricted portion,
called as a sphincterotomy, and come out. Previously this problem needed
a major operation. Now we can take biopsy of a growth of esophagus,
or from an ulcer in the stomach and decide for further line of treatment.
Now it is possible to coagulate the bleeding ulcer or inject the bleeding
varices with scope, thus saving many lives.
This was about endoscopy through the natural orifices. Our abdomen
is like a box containing many organs along with the 22 feet long intestine.
G.I.Scopes visualised the interior of the intestine. But what about
the other organs and the external surface, serosal surface of the intestine?
You can see ulcers and cancers of the intestine from inside but for
Tuberculosis or adhesions , Ascitis ( Fluid in the abdominal cavity)
or any lump or abnormalities of the uterus, tubes, ovaries, masses or
secondaries in the liver, it is necessary to enter the abdominal box.
It is called peritoneal cavity.
Laparoscopy- visualization of the abdominal cavity, laparo means abdominal
cavity. Scopy means visualization. It is also less popularly called
as peritonioscopy, because we see the peritoneal cavity through it.
It is an invasive procedure, because you have to make puncture to enter
the abdominal cavity, there is no natural orifice which will lead you
to the peritoneal cavity. Theoretically yes, the peritoneal cavity is
exposed to the outside through fimbrial openings of the tubes, leading
to the uterine cavity, vagina and ultimately out!
So to make a puncture, you have to give the patient anesthesia, and
make a sort of blind hole before you put in the scope and see the interior
of the abdominal cavity. That makes it more risky than the scopies which
are done through the natural orifices.