Amputation is one of the treatment options in cases of diabetic foot. However, deciding to do an amputation cannot be done immediately because of the high risk. Approximately 50% of diabetic foot patients who undergo amputation die within five years.


Should the Diabetic Foot be Amputated?
Ulcer Diabetic Foot

The increasing incidence of diabetes mellitus has contributed to increased complications, including diabetic foot cases. Patients with diabetes feet are more prone to infection. The diabetic foot infection is associated with peripheral artery disease and is accelerated by damage to nerves and blood vessels due to high glucose levels.

The healing process of diabetic foot wounds is also disrupted due to obstacles in the collagen synthesis phase. A diabetic foot that doesn't heal can cause serious morbidity, including emotional distress, loss of mobility, and significant financial burdens.

Most diabetic foot infections require surgical intervention, from minor procedures (debridement) to major procedures (amputations). However, with proper infection management and the development of endovascular techniques, it is hoped that the condition of infection, chronic injury, and peripheral artery disease in diabetic patients can improve so that the need for amputation of the diabetic foot decreases and the patient's life expectancy increases.


Overview of Diabetes Foot Management

Diabetic foot ulcers are deeper and easier to become infected. Definition Diabetic foot infection is simply an inframalleolar infection in people with diabetes mellitus. These include paronychia, cellulitis, myositis, abscesses, necrotizing fasciitis, septic arthritis, tendonitis, and osteomyelitis. The most common and classic manifestation of the lesion is an infected "mal perforation" foot ulcer. Aerobic gram-positive cocci are the main microorganisms that colonize and infect damaged skin. Staphylococcus aureus and β-hemolytic Streptococcus are the pathogens most often isolated.


Antibiotics

Evidence-based studies do not support antibiotic use in managing diabetic foot ulcers without clinical signs of infection, either to improve wound healing or as prophylaxis against infection. The reason is that administering antibiotics without properly indicated only encourages antimicrobial resistance, increases financial costs, and can cause drug side effects.

Identifying the infection's clinical signs is based on the presence of (pus) or at least 2 of the inflammation's manifestations ( such as erythema, warmth, swelling or induration, or pain). However, in some cases, it can be difficult to determine whether a chronic wound is infected or not, for example, when the foot appears ischemic, has an abnormal color or foul odor, has fragile granulation tissue, or if an ulcer fails to heal. In some of these dubious cases, a wound can be cultured, and brief antibiotic therapy is given according to the culture results.

Initial antibiotic therapy is usually empirical and should be based on the severity of the infection and microbiological data. For severe infections and extensive moderate infections, broad-spectrum antibiotic therapy can be the initial therapy. Antibiotic therapy can be continued until there is evidence that the infection has improved. But not continue until the wound has healed.


Surgery

Most diabetic foot infections also require surgical procedures, such as:
  • drainage of pus, 
  • debridement of infected and necrotic tissue, 
  • and revascularization of the lower extremities. 
Amputation in urgency is usually necessary only if there is extensive necrosis or life-threatening infection.


Various Considerations for Amputation in the Diabetic Foot

The purpose of amputation is to relieve pain and achieve rapid mobility with the use of a prosthesis. However, amputation should be the last option because this procedure causes significant morbidity and mortality risk in patients.


1. Presence of Infection Accompanied by Peripheral Artery Disease

Peripheral artery disease is a predictor of failure to heal from diabetic foot ulcers. As the infection progresses, peripheral artery disease becomes the main reason for lower limb amputation.

Chronic wounds need good blood flow to heal. If there is critical ischemia due to peripheral artery disease, there is a high probability that the ulcer will fail to heal.

The impaired peripheral perfusion due to arterial disease can be checked by Preoperative-Arteriographic and Ankle-Brachial Pressure Index (ABPI) measurements. However, it should be noted that this examination cannot help identify peripheral artery disease in the diabetic foot.


2. Determining the Amputation

The patient's symptoms, clinical findings, and the radiological examination (duplex ultrasound scan) will determine the need for and the degree of amputation of a diabetic patient's leg with chronic ischemia. These examinations are also important for patients who have undergone a revascularization procedure in angioplasty but failed to increase circulation to the lower extremities.

Digit (finger) amputation is rarely successful and often requires amputation at a higher level because of disease progression or incorrect preoperative initial assessments. The ischemic part of the limb needs to be examined carefully before surgery. And the intraoperative bleeding needs to be observed during surgery to assess the vessels. The amputation is usually performed to below the knee and is the gold standard. With this below-knee amputation, up to 80% of patients can be self-mobilized because the knee joint still is preserved, and the prosthesis is also lighter.


3. Revascularization

One of the measures to improve blood flow if there is a disturbance in the blood vessels is revascularization. Revascularization can be performed with endovascular angioplasty and bypass procedures with vascular grafts.

Percutaneous Transluminal Angioplasty(PTA) indications in classic diabetic peripheral artery disease are claudication and critical limb ischemia. Many medical centers have reported the successful use of aggressive endovascular interventions and vascular bypass procedures for diabetic foot vascular disease. The short-term effects are satisfactory with the healing of foot ulcers, thereby reducing the risk of amputation. However, further studies are still needed to confirm the long-term effects.

However, it is important to remember that a dangerous risk after successful revascularization is the reperfusion syndrome caused by the release of toxic metabolites and oxygen free radicals into the systemic circulation from ischemic limbs. This syndrome can cause severe cardiovascular collapse, kidney failure, and sometimes respiratory failure. Therefore, revascularization should not be performed in patients with signs of muscle necrosis and life-threatening sepsis. So, the preferred treatment option is amputation.

The bypass procedure with a vascular graft can prevent limb loss for at least two years if successful. The vascular graft's patency rate must be maintained at 75% for the bypass to be successful. However, there is some evidence that a failed vascular bypass will result in a higher amputation rate than a primary amputation (direct amputation without bypass).


Conclusion

Diabetic foot treatment must be done appropriately to reduce morbidity and mortality, including mortality after amputation. Amputation is the last resort chosen; if considered, there is no other way to better benefit and risk ratio. The purpose of amputation is to relieve pain and achieve rapid mobility with the use of a prosthesis. The decision to perform an amputation in a diabetic foot patient depends on the wound's local condition (extensive necrosis) and the patient's systemic condition (sepsis with the source of infection from the diabetic foot).


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