Lasers have various medical applications and are used in many surgical procedures. They allow for precise cutting or removal of tissue with limited damage to surrounding areas. Different types of lasers like CO2, Nd:YAG, and excimer lasers are used for applications like removing tumors, treating retinal disorders, and refractive eye surgeries. Lasers work by being absorbed selectively by tissues based on their wavelength and can be used to coagulate, vaporize, or ablate tissue. Precautions must be taken to prevent hazards from laser plume and potential misdirection of the laser energy.

1. Lasers in surgery
aditya kalyan

2. LASER
Light Amplification by Stimulated
Emission of Radiation

3. History
 Maiman ,1960, Ruby
 1962, Leon Goldman .
 Dr.Goldmans experiment was the first use of lasers in
the medical history
 Early 1980s, John Parrish and Rox Anderson -
Selective Photo Thermolysis - Risk of scarring &
damage to normal tissue

4. Common Components of Lasers

6. Production of Laser

10. Laser output
2 Modes
 Continuous mode (Watts)
 Pulsed mode (Joules)
Output depends upon the Medium

11. Properties
 Collimation

12.  Monochromacity
 Coherence

13. Effect of Laser on tissues

14. When a laser beam projected to tissue

15.  Biological activity of laser light is due to
Absorption phenomenon by chromophores
 Photons energy of laser light is transferred to
blood, tissues or bone in the form of heat.
 Laser can transfer photon energy to chemical bond
energy of the molecules in human body, like DNA.

16.  There are generally three interaction
mechanisms involved.
1) Photocoagulation
2) Photovaporization
3) Photoablation
 Thermal effects depend on Energy density.

17. Photocoagulation
 A Laser heating of tissues above 50 oC & below
100oC induces disordering of proteins and other
bio-molecules
 Shrink in mass – water expelled
 Heated region loses its mechanical integrity
 Cells in the photocoagulated region die and a region
of dead tissue called photocoagulation burn
develops

18. Applications
 Destroy tumors
 Treating Retinal disorders caused by diabetes
 Hemostatic laser surgery - bloodless incision,
excision:
Blood vessel subjected to photocoagulation
develops a pinched point due to shrinkage of
proteins in the vessel’s wall, helps seal off the flow.

19. Photovaporisation
 With very high power densities,lasers will quickly
heat the tissues to above 100o C
 water in tissues boils and evaporates.
 Since 70% of the body tissue is water, the boiling
change the tissue into a gas.
 Results in complete removal of the tissue.
 Hemostatic incision or excision, Skin
Rejuvenation, Resurfacing.

21. Photoablation
 When using high power lasers of ultraviolet
wavelength, chemical bonds are broken,without
causing local heating.
 Thermal component is relatively small and zone of
thermal interaction is limited
 Results in clean cut incision

22. Selective absorption
 A given color of light is strongly absorbed by one
type of tissue,while transmitted by another.
 Lasers’ pure color is responsible.
 Oxyhemoglobin in blood: Absorption of
UltraViolet, blue and green light
 Melanin a pigment in skin, hair, moles etc:
Absorption of visible and near Infrared light
 Water in tissues: Transparent to visible light

23. Selective absorption : Absorbing component being Melanin pigment in
hair and follicle, it is best worked with a Red light ruby laser. White hair
can not be treated with any laser due to the lack of absorbing component

25. Excimer Laser
 Excited Dimer
 Noble gas halide
 Photoablative effect-Cool Laser
 Ophthalmologic sugeries like LASIK,
PRK.

26. Argon Laser
 Tissue depth penetration only 1mm-
Superficial coagulation
 Precise cutting with minimal damage to
adjacent tissue
 Absorbed best in Red,Black tissue
 Retinal photocoagulation
 Arterial Recanalisation

28. Dye Laser
 Pulsed Lasers
 Organic Dyes like Kiton Red,Rhodamine.
 Tunable Lasers
 Dye can be replaced-Different wavelengths
with same laser
 Port-wine stains,Pigmented lesions

30. Co2 Lasers
 Most effective Laser Scalpel
 0.1mm zone of Histologic Necrosis
 Cutting & Vapourising Instrument
 Seals lymphatics as it cuts through,decreasing
spread of malignant cells
 Loss of tissues through Evaporisation
 Skin resufacing- Laser Facelifts

31. Nd:YAG Laser
 Most widely used in medical field
 High penetration capacity of >5mm
 Photocaogulation
 Endoscopic Laser
 To arrest bleeding GI varices
 Debulking GIT & Pulmonary tumours
 Coagulates Bladder tumour

32. Ho:YAG
 Treats tissue in a liquid-filled environment
(e.g., saline, blood)
 Endoscopic Laser
 Orthopaedic Laser used in Arthoscopy
Er:YAG
 Shallow penetration
 Extreme surgical precision

33. Diode Laser
 Semiconductor devices that emit Laser light as
electric current passes through them
 Tunable laser
 Fiberoptic delivery system
 Photocoagulation for general surgery
 Hair removal

34. KTP Laser
 Fiberoptic delivery system
 Cholecystectomy

35. Applications
Vascular Malformations of GIT
 Diffuse gastric antral vascular ectasia
 Colonic vascular malformation
 Argon & Nd:YAG lasers
 Photocoagulation therapy
 80% success rate in contolling recurrent
blood loss & subsequent transfusions

37. Upper GIT Carcinoma
 Early Gastric cancer
 Endoscopic laser therapy (Nd:YAG) can
eliminate cancers completely
 3 Requirments:Lesion <4cm with no
lymphnode metastasis,Followup,operator
 Advanced carcinoma it is a palliative
procedure to relieve obstruction,dysphagia
or bleeding

38.  Destroy neoplastic tissues & recanalise
lumen
 Relief of dysphagia 92%,perforation 10%
 Outpatient basis

39. Colorectal Cancer
 Laser therapy with Nd:YAG indicated in
 Patients with Metastatic or unresectable
local disease
 In Obstruction,Haemorrhage for Palliative
therapy

40. Liver
 Fibrotic Liver Resection
 Controlled resection of liver without
bloodloss possible
 Nd:YAG Laser with tissue contact tip
 Insitu ablation of Intrahepatic
malignancies (metastases)
 Palliation in HCC

41. Bile duct stones
 Laser Lithotripsy
 Coumarin pulsed dye laser
 For Bileduct stones that can’t be extracted
easily
 Break stones into small fragments which
pass spontaneously
 Light energy to Acoustic energy

42. Haemorrhoidectomy
 CO2 or Nd:YAG Laser with contact tip
 Like scalpel precisely cut through pile mass,
melt them & subsequent sloughing
Neurosurgery-Nd:YAG
 AV malformations
 Highly Vascular Meningiomas
 Lesions at inoperable sites like Base of
skull,midbrain,floor of fourth ventricle

43. Laparoscopic Surgery
 CO2 Laser
 Argon laser & Nd:YAG with contact tips
 Endometriosis
 Cholecystectomy (KTP/Nd:YAG)
 Lymphadenectomy (KTP)
 Posterior trunca vagotomy in peptic ulcer disease

44. Vascular Applications
 Laser Endarterectomy – Argon laser
 Smart Laser- Reflective Fluorescent spectral data
 Combination of Helium laser for fluorescence
excitation & Holmium laser for plaque ablation are
tried
 Laser Angioplasty – Co2,Argon,Nd:YAG
Laser angioplasty .av i

45.  Laser assisted balloon angioplasty done in
localised lesions of common iliac & superficial
femoral artery
 Prosthetic graft stenosis – Argon laser Angioplasty

46. Urology
 Renal stones - Laser lithotripsy
 Coumarin-based pulsed dye laser
 Light energy is delivered through Flexible quartz
fibers, directed Endoscopically onto a calculus
 Mechanism of action occurs via plasma
formation between the fiber tip and the calculus,
which develops an acoustic shockwave that
disrupts the stone along fracture lines
 Endoscopic extraction

47. BPH
 Photovaporisation - Tissue water is vaporized
resulting in an instantaneous debulking of
prostatic tissue.
 KTP or Greenlight is commonly used for its
vaporization effects on prostate tissue.
 Less bleeding and fluid absorption than standard
TURP
 Lack of tissue obtained for postoperative
pathological analysis

48. Urothelial stricture Disease
 Nd:YAG, KTP, and Ho:YAG lasers have all been
used experimentally to vaporize fibrous strictures
Urothelial malignancies
 Transitional cell carcinoma of bladder,
ureter, and renal pelvis
Skin lesions
 CO2 Lasers - Condyloma acuminata, Haemangioma
of external genetalia,early penile carcinoma.

49. Advantages
 Bloodless field
 Excellent Haemostasis
 Excellent Healing
 Allow precise Microsurgery
 Less postoperative pain & oedema
 Lower infection rate
 Outpatient procedure

50. Precautions

53. Laser Plume
 High Filtration surgical masks
 Smoke Evacuation units

54.  Drapes, Towels – Wet
 Fire Extinguisher, Water/Saline
 Water/Saline saturated fire retardant materials
 Laser safety officer- Hazard zone, Minimal access

55. Disadvantages
 Atmospheric contamination: Laser Plume
 Mutagenic,Teratogenic or vector for viral infection.
 Interstitial pneumonia
 Bronchiolitis
 Reduced mucociliary clearance, inflammation

56.  Misdirection of laser energy
 perforation of viscous or large blood vessels
 Eye damage
 Skin damage
 Fire and explosion:
 Gas embolism:
 laparoscopic or Hysteroscopic laser surgery

57. THANK YOU