Laser in Surgery

8/3/2019 Laser in Surgery

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SEMINAR PRESENTATION

DEPARTMENT OF SURGERY

ABUTH ZARIA


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USERS OF LASER IN SURGERY.

PRESENTERDR.IBRAHIM A.

MODERATORPROF.MBIBU.H

DATED 25TH;SEPT.2011.


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INTRODUCTION

Light

Amplification

by theStimulated

Emission

ofRadiation


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Introduction

A device that produces highly directional

light beam

Can be focused and positioned accurately

on a biological material

Has sufficient energy to affect the material

in a number of ways


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INTRODUCTION CONTD

Most medical applications rely on heat produced by laserlight

Laser light when absorbed is used in vapourizing,coagulating, or cutting tissues

Delivery of laser via optical fibres is useful in endoscopicprocedures

Non-thermal application is photodynamic therapy(PDT)


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Introduction contd

Einstein first conceptualized laser in 1917

First laser built 1960 Theodore H. Maiman(1960)

ruby crystals

Lasers were not used in operating room untilabout 1970

Can cause serious injury to patients, anaesthetistsand other theatre workers


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BASIC PHYSICS

Atom-consists of nucleus ( protons and neutrons)

and electrons

Quantum theory-electrons confined to certain energy levels

-can only move between these levels-by gaining or losing well defined amountof energy


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Resting atom: spontaneous emission of

radiation

Photon of

specific energy

strikes a resting

atom. Atom absorbs it

& gets excited

Excited atom

comes back to

resting state and

emits light

Energy

Absorbed energy

emitted


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Basic physics contd

Energy of radiation

E = hv

E =energy of the photons

h = planks constantV = photon frequency


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Basic Physics contd

Total intensity =k(nA)2

A = amplitude

n = total number of atoms

k = constant


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STIMULATION


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AMPLIFICATION


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Stimulated emission

Singular property of laser beam

Process that effectively dumps storedenergy from an active material into a light

beam passing through

Accurately alligned mirrors


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Basic composition of lasers Power source

Tube cavity with lasermedium

Mirrors total and partialreflecting

Laser media:

ruby crystals &Neodymium in yttriumaluminum garnet (ND-YAG)

Gases or mixture:

helium, argon, Co2 ,Excimer (exciteddimer)

Dye lasers: organic dyein liq soln.e.g.Rhodamine


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Generation of the beam


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Slide 25

K1 KHADIJAH, 9/29/2011


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Peculiarities contd

Laser Beams with wavelengths in a visible &

near the infrared portion of spectrum aretransmitted efficiently along flexible quartz

fibreoptic cables.


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Semiconductor

-Gallium arsenide laser

Liquid

. Dye lasers

Gas

. Argon

. C02

. Krypton

. Helium


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RUBY LASER


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Semiconductor laser


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Laser on tissue

Diff have diff absorption xteristics in tissue

Uv strongly absorbed, effect on surface only

As increase from blue>Green>Red, tissue become

more transparent and allow light to penetrate

Nd-YAG (near infrared = 1064) penetrate>argon (Blue= 488, green= 514)

As increases into the infra red region, tissue becomemore opaque and transmission reduces in the co2range ( = 10600nm) and hence effect limited on thesurface


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laser effects

No thermal effect at low intensity but can activatephotosensitive compd. leading to toxic reactions(photodynamic Therapy)

Photo thermal effect at high intensity for hemostasis,tumor vaporization, laser knife

Photomechanical effect lead to shock wave

Photo ablation effect (at extreme short interactiontime and peak pulse power


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USES OF LASERS

Broadly, lasers are used for

Photocoagulation of blood vessels.

Photo vaporization of unwanted tissues.

Photo fusion of adjacent structures.


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Surgical specialties uses

OPHTHALMOLOGY.

The 1st surgical specialty to use lasers

Treatment of diabetic retinopathy

Spot welding of retinal tears to prevent

detachment


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Ophthalmology contd

Iridectomy in closed angle glaucoma

Trabeculoplasty in open angle glaucoma

Ablation of posterior lens capsule(Intracapsular cataract extraction).


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Neurosurgery contd

Photocoagulation of brain aneurysms

(Argon lasers)

Neurosurgical pain relief (laser myelotomy or

anterolateral cordotomy).


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Thoracic surgery

Nd-YAG for obstructive bronchial ca viaendoscope

Coagulation of bleeders in haemoptysis

Intraluminal in operable/ non resectable tumors

Argon&Nd-YAG in laser assisted ballonangioplasty for impassable arterial obstruction.


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Thoracic surgery contd.

Cardiovascular surgery

- IHD (Ischaemic Heart Disease)

treatment using laser drills into

myocardium.

- Laser angioplasty of coronary &

peripheral arterial artheromas &thrombosis.


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Surgical specialities contd.

Gastroenterology:

- Control of upper GI Haemorrhage

(PUD, Varices, Ca).

- Hepatic resection eg PLCC or

secondaries.

- Haemorrhoids.


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Gastroenterology contd

Upper GIH (Nd-YAG) to ring the bleeders

Angiodysplasia, hereditary haemorrhagic

telangiectasia of stomach duodenum and colon

Oesophagitis, Mallory Weiss, gastritis

Palliation of malignant dysphagia


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Pancreatico-hepatibiliary system

Biliary calculi lithotripsy (Nd-YAG)

Recanalization of malignant stricture of bil. tree.

To allow endoscopic stenting

Hepatic resection (Nd-YAG) to reduce bld. loss(thermal knife)

Hemoistasis in liver trauma


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Urology contd.

Urology

- Bladder tumor resection

- TULIP (Transurethral Laser Induced

Prostatectomy)

- Internal laser urethrotomies in

strictures.

- Fragmentation of renal stones (Nd

YAG).


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Gynaecology contd.

Colposcopic treatment of CIN (CO2)

VIN and VaIN.(CO2)

Laser ablation of endometrium (Nd-YAG) in

menorrhagia (obviates hysterectomy)


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Benefits of lasers

High precision surgery, allows controlledpreservation of normal tissues.

Bloodless surgical field

Minimal wound contraction (No tissue reaction)

Provides No Touch surgery with better Asepsis.

Minimal pain and early convalescence


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Hazards

To Patient:

Excessive burning (injury to tissues other than

site being treated).

Visceral perforation

Excessive bleeding (ineffective in presence ofgross bleeding


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HAZARDS CONTD.

To Surgical Staff

Smoke inhalation and vaporization of viral and

bacterial particles Accidental skin exposure

Corneal or retinal burns

Fire hazards in presence of inflammableanaesthetic agents or high oxygen atmosphere.


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LASER SAFETY

The American National standard safe use of

laser in health facilities which was revised in

2002.

LASER Officer and LASER Committee

Staff training

Avoidance of litigation


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Laser safety contd

Use non-volatile anaesthetic agents

Using wet swabs to surround operation field

Suction to remove laser smoke/vapour.


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Documents

Laser in Surgery