I. Introduction to diabetic foot
Diabetic foot is a foot infection, ulcer and/or deep tissue destruction due to arteriopathy and local nerve abnormalities in the lower extremities caused by diabetes mellitus. It is a serious complication of diabetes mellitus and is highly disabling and lethal. According to WHO 2003 data, there are approximately 200 million people with diabetes worldwide. As the most common form of the disease, diabetes is often associated with lower limb amputation in Western countries, with the incidence increasing at a rate of 2.5% per year. For patients aged 65 to 74 years, combined diabetes increases the risk of amputation by a factor of 20. 20% of patients with diabetes will experience a diabetic foot during the course of their disease, and 33% will face amputation due to lower limb ischemia.
The general presentation of the diabetic foot: Symptoms usually occur unilaterally. If atherosclerosis is present in both limbs, there is usually a difference in the severity of the condition. Numbness in the legs and feet at rest, dullness or loss of sensation in the extremities; coldness in the legs and feet; loss of hair on the legs and/or feet, absence of sweating on the skin of the affected limbs; change in leg color; pallor or cyanosis (cyanosis) of the legs; leg pain or intermittent claudication after exercise (e.g., walking), relieved by rest; muscle pain in the lower extremities with a tingling or burning sensation, resting pain; diminished or absent pulses in the limbs; abnormal walking/gait. Deformity of the foot and, in severe cases, life-threatening lower limb ulcer formation, infection and even gangrene.
Special manifestations of diabetic foot: Patients with diabetic foot whose vasculopathy is very associated with neuropathy, most of these patients are asymptomatic or have only very mild symptoms (such as fatigue or cold feet), but do not develop significant claudication. Patients with diabetic foot have a late onset of symptoms and usually have ischemic disease of the limb by the time they are detected, with symptoms of resting pain, tissue loss or tissue ulceration.
Diabetes and Lower Extremity Ischemia: Diabetes often leads to narrowing or complete occlusion of the blood vessels in the lower extremities, resulting in inadequate local blood supply and the diabetic foot. Only by continuing to control blood glucose and reconstructing blood flow to ensure the blood supply needed by the tissues can we ensure the health of the lower extremity, preserve the limb and even save lives.
Characteristics of diabetic lower limb ischemia.
1, mainly occlusive lesions.
2, lesions in the systemic vascular lesions on the basis of more involved in the infrapopliteal artery and peripheral arteries.
3, after lower limb vascular occlusion in diabetic patients, the formation of collateral circulation is extremely poor, so often only one artery below the knee occlusion can also lead to serious limb ischemia performance.
4, the onset of the disease is low in age, and the difference in incidence between the sexes is reduced.
5. significantly accelerated progression of the disease, mostly combined with infection, which can rapidly progress to severe limb ischemia, ulcer formation, gangrene and even life-threatening.
6, arterial lesions are multi-segmental long-segment lesions, with high calcification.
Second, the diabetic foot lower limb ischemic stage.
Diabetic foot patients in the first stage of clinical symptoms or fontaine classification of stage II is an indication for treatment, the earlier the treatment, the better the outcome.
Diabetic foot clinical grading.
Phase I: Early lesion stage: Patients often have coldness, numbness and leg “cramps” in the lower extremities, which can be easily mistaken for “cold legs” or calcium deficiency in the elderly, resulting in delayed disease.
Phase II: Local ischemic phase: “intermittent claudication”, i.e. pain in the lower limbs after walking for a certain distance, forcing to stop the movement, which can be relieved after resting for a while, and then the pain reappears after walking for a certain distance again. As the disease progresses, the patient walks shorter and shorter distances. In addition, there is abnormal sensation in the foot, weak arterial pulsation, functional > organic.
Phase III: Dystrophic phase: Resting pain, i.e. pain in the lower extremity that occurs when the patient is not walking and resting, is severe burning pain, more so at night. The limb is dystrophic, with loss of arterial pulsation, organic > functional.
Stage 4: Gangrene: persistent severe pain, dry and wet ulcers, ischemic necrosis of tissues, which can be combined with infection and eventually lead to amputation and, in severe cases, can be life-threatening.
FONTAINE classification of diabetic lower limb ischemia.
Stage I Asymptomatic stage, with discomfort only after vigorous exercise.
Stage II Pain in the lower limbs when walking at normal speed.
Stage III Pain in the lower limbs at rest – resting pain.
Stage IV Lower limb pain in the resting state, accompanied by local nutritional disorders, dystrophic ulcers and gangrene.
Diagnosis of diabetic foot lower limb ischemia: A comprehensive judgment should be made through the clinical manifestations of the patient, general medical examination and various related vascular examinations.
Clinical symptoms: intermittent claudication, resting pain, foot infection, ulceration and necrosis.
general examination: lipids, blood glucose, coagulation index, transcutaneous partial pressure of oxygen, arterial palpation, etc.
non-invasive vascular examinations: ankle-brachial index, toe artery pressure, transcutaneous partial pressure of oxygen, ultrasound, CTA, MRA.
Arteriography: gold standard.
1, lower extremity artery palpation: mostly choose the dorsalis pedis artery and posterior tibial artery to check whether the local artery has pulsation, so as to understand the large vascular lesions in the foot. About 50% of diabetic patients cannot palpate the arteries of the foot, and those who have lost arterial pulsation in the foot should have ABI or N artery or even femoral artery palpation.
2.Ankle-brachial index (ABI) test
ABI = ankle systolic pressure/upper arm systolic pressure
ABI value Clinical significance
R0.9 Basically normal
0.71 C 0.89 Mild lower extremity arterial lesions
0.41 C 0.70 Moderate lesion
0.40 Below Severe lesions
ABI results can be falsely negative, exercise testing can improve sensitivity, and imaging or other further testing can be performed for ABI less than 0.9; treatment is required for less than 0.6. Patients with diabetes mellitus or renal disease can have calcification of the arteries in the lower extremities to the point that the arteries cannot contract and a false ABI elevation occurs, when toe artery pressure and TBI are measured. because calcification of the toe arteries rarely occurs, toe blood pressure <30 mmHg indicates severe limb ischemia.
3.The determination of transcutaneous partial pressure of oxygen (TcpO2) is used to detect limb ischemia, diagnosis of wounds, prediction of wound healing, selection of patients for hematologic reconstruction, decision of amputation and amputation plane, study of chronic foot injuries, diagnosis and treatment of venous ulcers, and quantitative evaluation of treatment.
4.Ultrasound examination of lower limbs
Color Doppler is commonly used to examine the degree of stenosis and blood flow in the femoral artery, N artery and dorsalis pedis artery, which can be observed in real time and can be quantitatively located and analyzed. It can be used for patient screening, preoperative examination and postoperative evaluation. However, sensitivity and specificity depend on the operator’s experience, and many color Doppler machines are not as sensitive for infrapopliteal artery examination.
5. MRA and CTA examinations
The examination is nearly noninvasive, convenient, and can show the morphology and lesions of the vessels after three-dimensional reconstruction. CTA examination is not suitable for patients with iodine allergy; the condition reflected by CTA is usually heavier than the actual condition; MRA is usually heavier than the actual condition; currently, it is mostly used in China for the general assessment of vascular lesions and surgical methods before operation.
6.Arteriography: the gold standard!
It is invasive, not suitable for patients with iodine allergy, and is usually used only for localization of lesions before surgical treatment (revascularization or amputation) or interventional treatment, which can provide a comprehensive understanding of the extent of vascular lesions, their degree and the formation of collateral circulation.
Current situation abroad: For most physicians in Europe and the United States, when the patient is clinically symptomatic and has an ABI of <0.9, angiography can be performed with or without ultrasound, because the technique is more mature and less invasive, and treatment can be performed at the same time as the examination. Ultrasound or angiography follow-up is taken after the operation.
Fourth, the treatment of diabetic foot lower limb ischemia: for patients with diabetic lower limb ischemia, various treatment methods are based on internal control of blood sugar and various medical diseases.
The main treatment methods are: drug therapy, stem cell therapy, surgery, interventional therapy.
1.Drug therapy: control of blood sugar —– throughout the end of treatment, for lifelong treatment, for all treatment basis.
Commonly used drugs: aspirin 100mg qd po.
Kaiser (Prostil) 5 to 10μg bid iv.
Ambulac 100mg bid/tid po bid for patients 65 years and older, tid for patients under 65 years.
PEDA 100mg bid po.
Bolivar 75mg qd po.
Oral medications may be used alone or in combination with two drugs.
Advantages: provides the basis for treatment, improves patient symptoms to some extent, partially heals ulcers, and is helpful for neuropathy.
Disadvantages: the treatment effect is poor in some patients and cannot reverse the stenosis or occlusive lesions caused by organic atherosclerosis.
2.Stem cell therapy: Stem cells are injected in a localized manner around the ischemic site.
Advantages: it has a relieving effect on clinical symptoms in some patients, especially those with ABI > 0.7.
Disadvantages: need to combine with other drugs, the effectiveness of the treatment is insufficient, lack of evidence-based medical basis, its efficacy has not been widely recognized abroad, for ABI <0.4 is basically ineffective.
3, surgical treatment: including vascular bypass surgery and amputation two.
Vascular bypass surgery: The use of artificial materials (ePTFE) or autologous vessels (saphenous vein, artery) to establish a bypass across the occluded vessel.
Disadvantages: the graft has the same problems of stenosis and occlusion; the surgery is very traumatic; it is difficult to heal the surgical wound in diabetic patients; most diabetic patients have vascular occlusion involving the infrapopliteal vessels, the usual rate of bypass surgery is very low; it is difficult to repeat the surgery.
Amputation: For the treatment of treatment failure, diabetic patients with ischemia of the lower limb itself, amputation may still occur after the trauma does not heal, seriously affecting the quality of survival of patients.
4, interventional treatment: minimally invasive interventional treatment of diabetic foot, namely “percutaneous peripheral angioplasty”, is a widely used internationally emerging efficient treatment of diabetic foot, through local puncture techniques, the use of special catheter guide wire and balloon, the lesion section of the blood vessels for expansion, with or without stents, in order to reopen The purpose is to reopen the narrowed or occluded blood vessels to improve the blood supply to the limbs.
V. Diabetic foot and minimally invasive interventional therapy: For patients with diabetic foot, interventional therapy is minimally invasive, safe, with a high success rate and low amputation and mortality rates, and has become the preferred treatment method in the international arena. Interventional treatment only requires a puncture at the root of the thigh, and with the help of special guidewires and catheters, a balloon is introduced to dilate the narrowed blood vessels, and special stents can be placed if necessary. With the development of minimally invasive interventional materials and techniques, experienced physicians can open all the occluded lower extremity vessels, including the dorsalis pedis artery, to directly improve the blood supply to the lower extremity, on the basis of which other therapeutic measures can achieve good results.
The advantages of interventional therapy.
1, high treatment success rate: interventional techniques can be successfully implemented in 85-90 % of patients.
2, low risk of treatment and few complications: the mortality rate of interventional treatment is almost zero, and the major complications such as bleeding and vascular entrapment are significantly reduced with the improvement of the operator’s technique, and the chance of serious consequences due to related complications is very small.
3, high rate of limb preservation after treatment: the amputation rate of patients treated with intervention is only 4%, and the amputation plane is significantly reduced, while the amputation rate of patients who do not take active treatment is as high as 33%, and most of them are high amputations.
4. Repeatable operation: The simple and safe operation can be easily repeated when necessary (e.g. in case of restenosis or re-occlusion), which is also safe and effective.
5, the treatment effect is obvious: after the intervention, the clinical symptoms such as intermittent claudication and resting pain can be relieved to varying degrees in most patients, and the healing of ischemic ulcers can be promoted.
6, is the only effective method for the treatment of infrapopliteal vascular occlusion: for infrapopliteal vascular occlusion, the patency rate of vascular bypass surgery is extremely low, drug treatment cannot reverse the ischemic lesions caused by vascular occlusion, only interventional treatment can directly reconstruct the blood flow in the lower leg through the method of intravascular lumen opening, and increase the blood perfusion in the foot to achieve the purpose of relieving lower limb ischemia.
7.Truly minimally invasive treatment: compared with the highly invasive open surgery, interventional treatment can be performed by puncture only, and recovery after treatment is fast.
8, interventional treatment only requires local anesthesia, with little side effects and without the various complications and risks of general anesthesia. More suitable for old and frail patients.
9, early detection and early treatment: lower limb ischemic diseases have a long onset time and the condition is easy to recur, so early treatment through minimally invasive intervention is easy to operate and has a high success rate, which can achieve a better treatment effect.
Sixth, diabetic foot peri-interventional adjuvant therapy: Interventional therapy is an important step in the treatment of diabetic foot, but not the whole treatment, the combination of various treatments can make the treatment of diabetic foot achieve the best effect.
Medication: lifelong treatment throughout the treatment of diabetes.
Preoperative: routine medical medication without special anticoagulation.
Intraoperative: systemic heparinization is required at the time of placement of the vascular sheath, usually an initial dose of heparin of 3000-5000u pushed intravenously, followed by additional heparin of 1000u/hour depending on the procedure.
Postoperative: selective anticoagulation depending on the intraoperative situation.
Routine postoperative lifelong oral aspirin 100mg/day.
If intraoperative balloon dilatation alone, Bolivar 75 mg/day combined with aspirin 100 mg/day for four weeks.
If a bare metal stent is placed intraoperatively, Bolivar 75 mg/day combined with aspirin 100 mg/day for 3 to 6 months.
If a drug-eluting stent was placed intraoperatively, Polivic 75 mg/day combined with aspirin 100 mg/day for 6 to 12 months.
Postoperative: continue medical treatment for blood glucose control and lipid regulation.
Surgical treatment: can be carried out in conjunction with interventional treatment, which can be carried out first to improve the blood supply to the lower extremities and then significantly reduce the amputation plane or only debridement of the local wound.
Most of the time, we can reduce the chance of occurrence of diabetic foot through general dietary control and care measures to protect the health of both feet.
1, timely detection and early treatment of diabetes, so that blood sugar control to near normal levels.
2, quit smoking, alcohol, exercise in moderation.
3, adhere to the diabetic diet, and give low cholesterol, light and easy to digest diet, eat more green leafy vegetables.
4, pay attention to foot inspection and care, daily inspection of the dorsum, soles and toes, there is no rough, dry, cracked, broken or blistered places, there is no abnormal feeling parts, when there is an abnormality in time to seek medical advice.
5, pay attention to foot hygiene, wear soft and loose socks, do not walk barefoot or wear shoes, it is best not to wear leather shoes, to prevent the skin from being squeezed and wear injuries. Every time before wearing shoes, you should check whether there are foreign objects such as nails in the shoes, whether the soles are flat, and the length of the shoes should be half an inch longer than the longest toe. Timely treatment of fungal infections of the feet such as gray nails.
6. If corns or calluses are found on the feet, prompt medical attention should be sought and the corresponding part of the shoe should be checked for protrusions.
7. to prevent diabetic foot, it is best to choose shoes that are specifically suitable for diabetic patients
8, adhere to the daily foot wash, every night with warm water and neutral soap wash feet (water temperature 37 ℃ -38 ℃), dry with an absorbent towel, and then evenly coated with protective oil on the foot, ulcerated wounds do not soak feet.
9, usually the feet can only keep warm, do not add heat. Prohibit the use of electric blankets or hot water bags, forbid the use of hot water to scald the feet, available thick soft wool socks to keep warm, the foot should be appropriate exercise to increase blood flow.
10, prohibit irritating potions, keep the local dry after each foot wash or bath.
11, trimming nails should not be too short, so as not to cause skin or nail furrows difficult to heal infection.
12.When diabetic patients have flushed, cold, painful and swollen feet, they should go to the hospital as soon as possible.
13, once the foot ulcers and even gangrene, should immediately seek medical attention.
In short, diabetic foot threatens the health of the legs of the majority of diabetic patients, and even lead to amputation and even life-threatening risk, but through the early awareness of the condition of diabetic patients, the strengthening of self-protection awareness, as well as a variety of doctor’s examination and treatment, early prevention, early detection and early treatment, you can try to avoid the tragedy. Therefore, once a diabetic patient develops local skin blisters, sensory loss, skin ulcers and other lesions, he or she should go to the hospital promptly, and the doctor will choose the appropriate examination and treatment according to the patient’s specific situation.