WET GANGRENE

Gangrene is not specific type of necrosis but is a coagulative necrosis occurring due to the loss of blood supply.
This term is used when there necrosis of distal part of limb particularly lower leg and necrosis involving entire thickness of the bowel wall or abdominal viscera.
Types of the gangrenes
- Dry gangrene – dead necrotised tissue remains uninfected.
- Wet gangrene-necrotic tissue becomes infected.
- Gas gangrene – Wet gangrene infected by one of the gas forming Clostridia

Wet gangrene typically occurs in
- Diabetic foot –High glucose content in the necrosed tissue favours bacterial growth.
- Bed sores –In bed ridden patients at the pressure on the sites like sacrum, buttocks and heel
- Also in organs like bowel (due to strangulated hernia, volvulus or intusscesception ) lung, mouth, cervix and vulva
Wet gangrene develops more often from the venous blood blockage and also occurs if there is both venous and arterial blood blockage.
Affected part is stuffed with blood which favours rapid growth of putrefactive bacteria
Infection spreads rapidly into the variable tissue adjacent to necrosis.
Even the toxic products formed by the bacteria are absorbed in the circulation causing systemic manifestations like high fever, toxaemia later leading to death
Morphologic features:
- Grossly the affected part is black, rotten, and soft and pulpy.
- The affected part is dark black colour due to release of haemoglobin from the haemolysed RBC’s. This is again acted upon by the hydrogen disulfide produced by bacteria which results in the formation of black iron sulphide
- Microscopically the tissue shows caogulative necrosis with extensive areas of haemorrhage.
- In the bowel, mucosa is ulcerated and sloughed. Intense acute inflammatory cell infiltrate and thrombosed vessels can be seen.
- Line of demarcation between variable and necrosed tissue is absent.