GANGRENE
DEFINITION -
IS A FORM OF NECROSIS OF TISSUE WITH
SUPERADDED PUTREFACTION
GANGRENE IS CAUSED BY ISCHAEMIA OR
INFECTION
GANGRENE
NECROSIS IS USUALLY COAGULATIVE DUE TO
ISCHAEMIA WITH SUPERADDED
PTREFACTION BY PUTREFYING BACTERIA
- EXAMPLE –GANGRENE OF THE
BOWEL,GANGRENE OF THE LIMBS
CAUSES OF GANGRENE
ANY CONDITION THAT AFFECTS BLOOD FLOW
INCREASES THE RISK OF GANGRENE, INCLUDING:
1.DIABETES
2. ATHEROSCLEROSIS
3. PERIPHERAL ARTERIAL DISEASE
4.TRAUMA OR INJURY
5. RAYNAUD'S PHENOMENON (A CONDITION IN
WHICH THE BLOOD VESSELS THAT SUPPLY THE SKIN
BECOME INTERMITTENTLY NARROWED –CAUSE IS
NOT KNOWN)
RAYNAUD'S PHENOMENON
PRIMARY RAYNAUD'S IS WITHOUT AN
UNDERLYING DISEASE OR ASSOCIATED
MEDICAL PROBLEM THAT COULD PROVOKE
VASOSPASM.
ATTACKS ARE TRIGGERED BY EXPOSURE TO
COLD AND/OR STRESS, SYMMETRIC
BILATERAL INVOLVEMENT, NO DETECTABLE
UNDERLYING CAUSE,
RAYNAUD'S PHENOMENON
NORMAL CAPILLAROSCOPY FINDINGS,
NORMAL LABORATORY FINDINGS FOR
INFLAMMATION, AND AN ABSENCE OF
ANTINUCLEAR FACTORS. SYMPTOMS OF
RAYNAUD'S PHENOMENON DEPEND ON THE
SEVERITY, FREQUENCY, AND DURATION OF
THE BLOOD-VESSEL SPASM .IT IS
ACCOMPANIED BY PARESTHESIAS AND PAIN
RAYNAUD'S PHENOMENON
INITIALLY, THE DIGIT(S) INVOLVED TURN
WHITE BECAUSE OF THE DIMINISHED BLOOD
SUPPLY. THE DIGIT(S) THEN TURN BLUE
BECAUSE OF PROLONGED LACK OF OXYGEN.
FINALLY, THE BLOOD VESSELS REOPEN,
CAUSING A LOCAL "FLUSHING"
PHENOMENON, WHICH TURNS THE DIGIT(S)
RED.
RAYNAUD'S PHENOMENON
THIS THREE-PHASE COLOR SEQUENCE (WHITE
TO BLUE TO RED), MOST OFTEN UPON
EXPOSURE TO COLD TEMPERATURE, IS
CHARACTERISTIC OF RAYNAUD'S
PHENOMENON
RAYNAUD'S PHENOMENON
GANGRENE DUE TO RAYNAUD'S
PHENOMENON
RAYNAUD PHENOMENON
CHRONIC, RECURRENT CASES OF RAYNAUD
PHENOMENON CAN RESULT IN ATROPHY OF
THE SKIN, SUBCUTANEOUS TISSUES, AND
MUSCLE. IN RARE CASES IT CAN CAUSE
ULCERATION AND ISCHEMIC GANGRENE
GANGRENE
SECONDARY RAYNAUD'S WHICH IS A
SYNDROME CAUSED BY A KNOWN PRIMARY
DISEASE, MOST COMMONLY CONNECTIVE
TISSUE DISORDERS SUCH AS SYSTEMIC LUPUS
ERYTHEMATOSUS, SCLERODERMA
GANGRENOUS OR NECROTISING
INFLAMMATION
IN THIS CASE INFLAMMATION IS PRIMARY
PROVOKED BY A VIRULENT BACTERIA
RESULTING IN MASSIVE TISSUE NECROSIS.
EXAMPLE – GANGRENOUS APPENDICITIS,
GANGRENOUS STOMATITIS(NOMA OR
CANCRUM ORIS)
GANGRENOUS OR NECROTISING
INFLAMMATION
THE RESULT OF NECROTISING OR
GANGRENOUS INFLAMMATION
AND
GANGRENE IS THE SAME
BUT THE MECHANISM IS DIFFERENT
3 MAIN FORMS OF GANGRENE
THERE ARE DIFFERENT TYPES OF GANGRENE
WITH DIFFERENT SYMPTOMS
1.DRY GANGRENE
2.WET GANGRENE
3.GAS GANGRENE
DRY GANGRENE
BEGINS IN THE DISTAL PART OF THE LIMB
DUE TO ISCHAEMIA AND OFTEN OCCURS IN
THE TOES AND FEET OF ELDERLY PATIENTS
DUE TO GRADUAL LOSS OF BLOOD SUPPLY AS
IN ATHEROSCLEROSES
DRY GANGRENE
OTHER CAUSES OF DRY GANGRENE FOOT ARE
THROMBOANGITIS OBLITERANS ,ALSO KNOWN
AS BUERGER’S DISEASE (THROMBOANGIITIS
OBLITERANS - BUERGER'S DISEASE IS A
RECURRING PROGRESSIVE INFLAMMATION AND
THROMBOSIS OF MEDIUM SIZED ARTERIES AND
VEINS OF HANDS AND FEET) ,
DRY GANGRENE
RAYNAUD’S DISEASE,TRAUMA ,
ERGOT POISONING - INGESTION OF THE
ALKALOIDS PRODUCED BY THE CLAVICEPS
PURPUREA FUNGUS THAT AFFECTS RYE
GRAIN - THE DRY GANGRENE IS A RESULT OF
VASOCONSTRICTION INDUCED BY THE
ERGOTAMINE-ERGOCRISTINE ALKALOIDS OF
THE FUNGUS.
DRY GANGRENE
STARTS IN ONE OF THE TOES WHICH IS
FARTHEST FROM THE BLOOD
SUPPLY,CONTAINING VERY LITTLE BLOOD
THAT EVEN INVADING BACTERIA FIND
DIFFICULT TO GROW IN THE NECROSED
TISSUE
DRY GANGRENE
THE GANGRENE SPREADS SLOWLY UPWARDS
UNTIL IT REACHES A POINT WHERE THE
BLOOD SUPPLY IS ADEQUATE TO KEEP THE
TISSUE VIABLE
THUS A LINE OF SEPARATION IS FORMED
DRY GANGRENE -MORPHOLOGY
GROSS
THE AFFECTED PART IS DRY,SHRUNKEN AND
DARK BLACK(DUE TO PRODUCTION OF BLACK
IRON SULFIDE)
RESEMBLES A FOOT OF MUMMY
DRY GANGRENE -MORPHOLOGY
THE LINE OF SEPERATION BRINGS ABOUT
COMPLETE SEPERATION WITH EVENTUAL
FALLING OF THE GANGRENOUS TISSUE
DRY GANGRENE -GROSS
DRY GANGRENE -MORPHOLOGY
MICROSCOPY –
NECROSIS ( COAGULATION NECROSIS)
GRANULATION TISSUE AT THE LINE OF
SEPERATION
DRY GANGRENE - MICROSCOPY
GRANULATION TISSUE
WET GANGRENE
OCCURS IN NATURALLY MOIST TISSUES AND
ORGANS SUCH AS MOUTH,
BOWEL,LUNG,CERVIX, VULVA etc
EXAMLE – DIABETIC GANGRENE DUE TO HIGH
SUGAR CONTENT IN THE NECROSED TISSUE
WHICH FAVOURS GROWTH OF BACTERIA
WET GANGRENE
BED SORES IN BED RIDDEN PATIENT DUE TO
PRESSURE ON SITES LIKE
SACRUM,BUTTOCKS AND HEELS IS ANOTHER
EXAMPLE OF WET GANGRENE
WET GANGRENE
DEVELOPS RAPIDLY DUE TO BLOCKAGE OF
VENOUS, AND
LESS COMMONLY,ARTERIAL BLOOD FLOW
FROM THROMBOSIS AND EMBOLISM
WET GANGRENE
THE AFFECTED PART IS STUFFED WITH
BLOOD WHICH FAVOURS RAPID GROWTH OF
PUTREFACTIVE BACTERIA
WET GANGRENE
WET GANGRENE
WET GANGRENE- MORPHOLOGY
TOXIC PRODUCTS FORMED BY BACTERIA ARE
ABSORBED CAUSING SYSTEMIC
MANIFESTATION OF SEPTICAEMIA, FINALLY
DEATH
RAPIDLY SPREADING WET GANGRENE LACKS
CLEAR CUT LINE OF DEMARCATION
WET GANGRENE- MORPHOLOGY
GROSS –
AFFECTED PART IS SOFT, SWOLLEN,PUTRID
,ROTTEN AND DARK
EXAMPLE –GANGRENE OF THE
BOWEL,COMMONLY DUE STRANGULATED
HERNIA, VOLVULOUS OR INTUSCEPTION
WET GANGRENE- MORPHOLOGY
THE PART IS STAINED DARK
MICROSCOPY – COAGULATIVE NECROSIS WITH
STUFFING OF AFFECTED PART WITH BLOOD.
ULCERATION OF THE MUCOSA WITH SEVERE
ACUTE INFLAMMATION
LINE OF DEMARCATION IS NOT CLEAR CUT
GAS GANGRENE
IS A SPECIAL FORM OF WET GANGRENE
CAUSED BY GAS FORMING
CLOSTRIDIA(GRAM- POSITIVE ANAEROBIC
BACTERIA) WHICH GAIN ENTRY INTO THE
TISSUES THROUGH OPEN CONTAMINATED
WOUNDS
GAS GANGRENE
CLOSTRIDIA PRODUCE VARIOUS TOXINS
WHICH PRODUCE NECROSIS,EDEMA LOCALLY
THE TOXINS GET ABSORBED AND
PRODUCING SEVERE SYSTEMIC
MANIFESTATIONS
GAS GANGRENE - MORPHOLOGY
GROSS AFFECTED AREA SWOLLEN,
EDEMATOUS,PAINFUL AND CREPITANT DUE
TO ACCUMULATION OF GAS BUBBLES WITHIN
THE TISSUES
THE AFFECTED TISSUE BECOME DARK BLACK
AND FOUL SMELLING
GAS GANGRENE - MORPHOLOGY GROSS
GAS GANGRENE - MORPHOLOGY
MICROSCOPY –
COAGULATIVE NECROSIS WITH LIQUIFACTION
AND LARGE NO OF GRAM +VE BACILLI ARE SEEN
AT THE PERIPHERAL ZONE CONGESTION ,
EDEMA ,LEUKOCYTIC INFILTRATE WITH
CAPILLARY AND VENOUS THROMBI
DIFFERENCES BETWEEN DRY AND
WET GANGRENE
FEATURES
DRY GANGRENE
WET GANGRENE
1, SITE
COMMONLY LIMBS
MORE COMMON IN
BOWELS
2,MECHANISM
ARTERIAL OCCLUSION
MORE COMMONLY
VENOUS OCCLUSION
MACROSCOPY
ORGAN –DRY,SHRUNKEN
AND BLACK
MOIST ,SOFT,
SWOLLEN,ROTTEN AND
DARK
PUTREFACTION
LIMITED , DUE TO VERY
LITTLE BLOOD SUPPLY
MARKED DUE TO
STUFFING OF ORGAN
WITH BLOOD
LINE OF DEMARCATION
PRESENT AT THE
JUNCTION BETWEEN
HEALTHY AND
GANGRENOUS PART
NO CLEAR LINE OF
DEMARCATION
BACTERIA
BACTERIA FAIL TO SURVIVE NUMEROUS