Under the Knife: A History of Surgery in 28 Remarkable Operations

by Arnold van de Laar

called the ‘wound bed’. The state of the wound bed is crucial to what follows. In a wound caused by a sharp knife, the wound bed will hardly be damaged. The edges of the wound will remain unharmed and the healthy tissues will allow the immune system to kill any bacteria that enter the wound. A clean cut with a sharp knife can even be closed up again immediately, if you rinse it out quickly with water, soap or disinfectant. This is primary healing or healing in the first instance (per primam). If the cut is not clean, the wound will become infected, producing pus. The infected wound can then no longer be closed up per primam and will have to heal per secundam, through secondary healing or ‘healing in the second instance’. However, the healthy wound bed also guarantees a sufficient supply of oxygen. As the Clostridium perfringens bacteria cannot survive in the presence of oxygen, gas gangrene has little chance in a healthy cut, no matter how dirty the wound may be. In the case of a crush wound, by contrast, the tissues are damaged by bruising, crushing or tearing. Consequently, the blood vessels in the wound bed are also damaged, reducing the supply of oxygen.