الفهرس 
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Abstract
Lasers especially the C02 laser are now widely used in surgery,
but a little data are available for the effects of the plume (vapor) byproducts
resulting from laser surgery.
Many researchers have suggested that the smoke is extremely
hazardous to the patient and the surgeons or operating room
personnel. Some of them were suggested that the laser vapor might
transmit viruses e.g.
• Human papilloma virus (HPV), intact HPV DNA was
detected in vapor of C02 laser smoke.
• Human immunodeficiency virus (HfV) DNA was also
present in the laser smoke as a result of vaporization of
concentrated tissue culture pellets infected with mv by
C02 laser.
• Viable bacteriophage particles were detected as a result of
vaporization of an agar substrate containing high titres of
bacteriophage.
• Laser Smoke was capable of disseminating viable tumor
tissue at least locally is an air born fashion, but other study
was suggested that viable cells was unlikely present in the
laser smoke.
The smoke particles of laser were found. to be mutagenic to
salmonella typhi. strain. Also, bacterial dissemination may occurs
as a hazard of the laser smoke. Others suggested that the laser
smoke may be hazardous to the respiratory system, the smoke may
lead to deposition of the fine particulate matter in the alveoli
resulting in from extensive pathology. The laser smoke may also
lead to decrease in the arterial POz, mild hypoxia and depressed
tracheal mucus velocity.
In our study we try to find an answer to the question
concerning the hazardous effects of the COz laser smoke on the
bronchopulmonary system. We use twenty rabbits of the same
species divided into five groups (four rabbits each) and exposed to
the COz laser smoke for different periods of time the 1st group was
exposed the COz laser smoke for 10 minutes, the 2nd group was
exposed the COz laser smoke for 20 minutes, the 3rd group was
exposed the COz laser smoke for 30 minutes, the 4th group was the
chronic group of exposure to the COz laser smoke for 3-4 weeks
and 5th group was the control group.
We use a glass chamber measuring 15 cm wide X 25 em length
X 12 em height. The smoke was obtained by vaporization of human
tonsils by the use of COz laser apparatus at a power of 4 watts and
200 HZ frequency.
The rabbits were sacrificed at different periods of time then
dissection of the respiratory system of rabbit was done and
examined electron microscopically & histopathologically. We get
the following results:
• At 10 minutes exposure to C02 laser smoke:
a- Electron microscopical results :
There are massive invasion of lymphocytes, loss of cilia and
microvilli, sub-epithelial proprial edema, swollen collagenic fibrils,
numerous destructed mitochondria, macrophages having phagocytic
bodies with various stages of deterioration and the neutrophils
having large vacuolated granules and smaller specific granules.
b- Histopathological results :
Pulmonary inflammatory response as an interstitial congestion
of the lung tissue, congested blood vessels with edematous thick
wall and distended alveolar sacs and ducts.
• At 20 minutes exposure to C02 laser smoke:
a- Electron microscopical results :
There are: Darkly stained pyknotic nuclei, disturbed epithelial
cells with destructed cytoplasmic organelles & mitochondria,
intercellular irregular spaces, loss of microvilli & apical cilia with
destruction of their apical borders, numerous oesinophilia with
phagocytic vacuoles and hypochromatic nuclear lobes, nuclear
vacuolation in pneumocyte type II and complete destruction of
mitochondria & endoplasmic reticulum.
b- Histopathological results :
Interalveolar hemorrhage with hemosidirin deposits, dilated
broncheoles, lymphocytic aggregation, focal areas of interstitial
pneumonia and interstitial congestion with atrophy of some alveoli
but dilated others.
• At 30 minutes exposure to C02 laser smoke:
a- Electron microscopical results :
Extruded pyknotic nuclei, destructed cilia of most of tracheal
cells, numerous number of intercellular lysosomes, irregular
lobulated nuclei with abundant euchromatin & few
heterochromatin, interalveolar phagocytic macrophages having
intracytoplasmic phagocytic matter, hypochromatic nuclei, less
lamellar bodies, sub-epithelial blood capillary surrounded with
collagenic fibrils the cytoplasm of endothelial cell having a lot of
vacuoles and Interstitial hemorrhage inbetween lung alveoli.
b- Histopathological results :
Detached endothelium with hyalinization swollen wall of blood
vessels with peri-vascular edema, lymphocytic aggregation with
lymphoid follicle formation, compensatory emphysema &
interstitial pneumonia, thrombosed pulmonary capillaries,
desquamation of the lining epithelium, intra-alveolar migration of
phagocytic cells and the goblet cells becomes more thin with
atrophic changes.
• Chronic exposure group to the C02 laser smoke:
a- Electron microscopical results :
Dividing basal cells while the other cells reveals pyknotic
nuclei, sub-epithelial dividing cell with abnormal mitochondria, an
abnormal goblet cell having destructed vacuolated nucleus, a
special type of destruction to the nuclei in the form of boundary
vacuolation, Some goblet cells having no nucleus due to karyolysis
or karyorrhexis, an extruded pyknotic nucleus, complete extrusion
may occur with vacuolated appearance of its place, degenerated,
destructed mitochondria and endoplasmic reticulum, Atrophy of
goblet cells with few mucus granules, peri-nuclear halo formation,
irregular pyknotic nuclei with degenerative changes, active septal
macrophages having irregular nuclei with destructed engulfed
particles, intracytoplasmic smoke black granules of variable sizes &
shapes, abnormal aggregation of blood platelets, an active
fibroblasts which forms new collagenic fibrils, abnormally formed
collagenic fibrils, active macrophage engulfed carbon particles,
squamous metaplasia the columnar ciliated epithelium was changed
into flattened ciliated epithelium.
b- Histopathological results :
We get the following results: emphysema, thickened blood
vessel walls with hyaline degeneration, abnormal chondrocytes,
lung collapse & fibrosis, hyalinization of broncheoles & blood
vessels and metaplastic changes in the form of :
• The endothelium showing patchy areas of perpendicular
endothelial cells.
• Stratification of endothelium.
• Beginning of metaplastic changes of epithelial lining of
broncheoles.
• Blebs protrusions in the apical border of most upper cells of
metaplastic epithelium in the trachea .
• Statistical Results :
The following significant data were verified:
In electron microscopical study:
Nuclear changes .Cell division, nuclear vacuolation, extruded
nuclei, nuclear destruction, pyknotic nuclei & hypochromatosis.
Cellular changes .lymphocytosis, loss of cilia & microvilli,
destructed mitochondria, active fibroblasts, abnormal collagenic
fibres, smoke granules, increased intracellular lysosomes, goblet
cell atrophy, squamous metaplasia & blood capillary roughness.
In histopathological study:
The following significant data were observed:
Emphysema, thrombosed pulmonary capillaries & arterioles,
metaplastic changes, lymphocytic aggregation, hyalinization of
blood vessel walls, inter-alveolar hemorrhage, interstitial
congestion, destructed cilia, atrophic thin goblet cells, interstitial
fibrosis, phagocytic cell migration and desquamation of epithelial
cells.
On Conclusion :
Laser plume is considered as one of the complications of the
surgical laser procedures. So, we must provide two suction set-ups
for all upper aerodigestive tract procedures one to remove smoke
and steam from the operative field, the other to remove blood and
mucus from the wound. Positioning of the nozzle of smoke
evacuator at a distance of two inches from the laser interaction site
was founded to be adequate.
Filters should be used in the suction lines and several smoke
evacuation systems must be used to capture emissions from these
procedures. Also, a special high efficiency masks are required to
catch laser plume particles.