Gangrene is a serious condition in which the occluded supply of blood results in the death and decay of body tissue. Gangrene is actually the end result of tissue ischemia that can have many underlying and overlapping causes. In the extremities muscle tissue is particularly vulnerable to ischemia. However, gangrene can affect any part of the body, but most commonly starts in the fingers and toes. The most common causes of gangrene include infection, traumatic injuries, and long-term conditions that restrict blood circulation, including diabetes, vascular diseases, arterial steal syndrome secondary to the AV fistula and Raynaud’s phenomenon. Microvascular thrombosis which is often associated with disseminated intravascular coagulation (DIC) can also lead to two additional forms of gangrene where the pulses remain in intact. One is venous limb gangrene and the other is symmetrical peripheral gangrene.6 Once the flow of blood is completely blocked, the area affected by the impeded vessels will eventually turn blue, with other extreme skin changes, pain, coldness, and a foul-smelling discharge also occurring in most cases. Urgent treatment is crucial, as the condition can lead to death if treatment is delayed, the gangrene is too extensive, or the person has other significant medical problems. Management may include a combination of medical and surgical interventions like fasciotomies and amputations. Amputation may be necessary in severe cases to prevent the spread of gangrene to other parts of the body and save the patient's life.1,2,6
Pathophysiology
- Any event or condition that narrows blood vessel(s) and/or contributes to the complete obstruction of blood flow can lead to gangrene, with some of the most common causes including infection, injury, and long-term conditions affecting blood circulation
- Conditions that increase the chances of gangrene developing include diabetes, atherosclerosis, peripheral arterial disease, and Raynaud’s phenomenon
- Traumatic injuries that damage the skin and/or tissues such as car accidents, frostbite, and burns can all result in blood loss, and open wounds can also be vulnerable infection, which collectively can increase the chances of developing gangrene
- In critically ill patients, venous gangrene of the hand or upper limb can result from the placement of an indwelling venous catheter2
- Gangrene of the hand can also result from unsuccessful attempts at internal jugular vein cannulation, which can lead to upper limb vein occlusion and eventually gangrene2
- Immunosuppression, which can result from chemotherapy or radiation, history of injecting drugs, malnutrition, older age, obesity, kidney failure, alcohol abuse, and smoking, is also associated with a higher risk for gangrene
- Other factors that can increase the risk for gangrene include asplenia, previous cold injury to extremities, renal failure, increased sympathetic tone, and the use of vasopressors1
Related Anatomy
- Gangrene is typically classified into two primary types:
- Dry gangrene
- Starts more slowly than wet gangrene
- Commonly associated with chronic diseases like diabetes and atherosclerosis
- Wet gangrene
- More aggressive form of gangrene
- Associated with infections of affected tissues
- May occur and progress in diabetic patients with neuropathy
- Gas gangrene, or clostridial myonecrosis, is a particularly virulent form of wet gangrene that can affect the hands and upper extremities. This infection is associated with poorly irrigated and debrided wounds. These infections are frequently cause by traumatic wounds that are exposed to contaminated soil like that found in a barn yard.3
- Dry forms of gas gangrene can also result from a progressive loss of blood supply to tissues, and can become wet if they develop a bacterial infection
- Other less common types of gangrene include internal gangrene, which can be due to surgical complications, necrotizing fasciitis (NF) and Fournier’s gangrene (NF of the perineal and genital areas). These infections are sometimes referred to as emolytic streptococcal gangrene
Incidence and Related Conditions
- Gangrene of the hand associated with acute venous occlusive disease of the upper limb is rare, with only 16 cases reported as of 20092
- The annual incidence of atheroembolism that leads to ischemic gangrene in atherosclerosis patients is 0.3–3.5% overall, but can rise to 30% after vascular procedures4
- The annual incidence of gas gangrene in the U.S. is approximately 3,000 cases5
- Urosepsis
- Sepsis
- Phlegmasia cerulea dolens
- Vascular insufficiency
- Microbial infection
- Ischemia
- Necrosis
Differential Diagnosis
- Staphylococcal skin lesions
- Erysipelas
- Cellulitis
- Insect bite
