Diabetes mellitus is a series of metabolic disorder syndrome caused by the action of various pathogenic factors on the organism. With the improvement of people’s living standards, the incidence of diabetes is increasing dramatically in recent years [1]. In 1999, the World Health Organization (WHO) defined diabetic foot as a combination of neuropathy and various degrees of peripheral vasculopathy in diabetic patients resulting in lower limb infection, ulcer formation, and/or deep tissue destruction. The treatment of diabetic foot requires a combination of pharmacological and surgical management, especially the selection of the correct surgical management has a pivotal role in reducing the disability rate, saving limb function and reducing the amputation segment. In this paper, the current status of diabetic foot classification and surgical treatment is reviewed as follows. Liu Ping, Department of Peripheral Vascular Disease, The First Affiliated Hospital of Henan College of Traditional Chinese Medicine
1. Classification methods of diabetic foot
1.1 Wagnerer grading system: the most commonly used classical grading method. According to the clinical manifestations, there are 6 grades from 0 to 5: Grade 0: foot with risk factors for foot ulcers, currently without ulcers; Grade 1: foot skin surface ulcers, clinically without infection; Grade 2: deeper ulcers, often combined with soft tissue infection, without abscess or infection of bone; Grade 3: deep infection with bone tissue lesions or abscess; Grade 4: limited gangrene (toe, heel or forefoot dorsum) Grade 5: total foot gangrene. This method describes the extent of the diabetic foot well, but does not reflect the natural course of the diabetic foot, making it difficult to distinguish whether the gangrene is due to ischemia or infection. And whether ischemia or infection makes a difference in its treatment and prognosis.
1.2 University of Texas diabetic foot classification [2]: this classification assesses the depth of ulceration, the degree of infection and ischemia. The degree of grading is divided into 4 grades according to the depth of ulcers, such as grade 1: history of ulcers; grade 2: superficial ulcers; grade 3: deep to tendons; and grade 4: involvement of bones and joints. The grading is divided into 4 stages according to the cause of the ulcer, such as A: no infection and ischemia; B: infection; C: ischemia; D: infection and ischemia. Performing ulcer classification requires a combination of grading and staging that assesses the depth of the ulcer, the degree of infection and ischemia, and takes into account both etiology and extent. Investigations have demonstrated that amputation rates increase with the severity of the ulcer and staging. For non-infected, non-ischemic ulcers, there was no amputation during follow-up; for ulcers deep to bone tissue, the amputation rate increased 11-fold; if infection and ischemia coexisted, the amputation rate increased nearly 90-fold. This method is relatively complex, less used in clinical practice and mostly applied in scientific research, but it is superior to the Wagner grading system in determining prognosis [3].
1.3 Simple grading system classified according to the natural course of the disease [4]: a simple grading system established by Edmonds and Foster based on the natural course of podiatric disease. This method has 6 grades: grade 1 low risk with no neurological or vascular lesions; grade 2 high risk with neurological or vascular lesions plus risk factors such as callus, edema and foot deformity; grade 3 ulcer formation; grade 4 foot infection; grade 5 gangrene; and grade 6 irretrievable foot. This method facilitates the development of management and preventive measures for stratified management according to the patient’s risk level.
1.4 Classification according to the nature of the lesion: there are 3 clinical types: wet gangrene, dry gangrene and mixed gangrene [5]. Wet gangrene is more common clinically, accounting for about 75% of diabetic feet, and is often associated with peripheral neuropathy, infected septic skin injury, and in severe cases, often with general malaise, toxemia or sepsis, and other clinical manifestations. Dry gangrene is less common, accounting for only 5% of patients with diabetic foot gangrene. Mixed gangrene accounts for about 20% of patients with diabetic foot, and is generally more severe, with more ulcerated areas, larger areas, often involving large parts or all of the hand and foot, and a higher rate of amputation.
1.5 Classification according to etiology: diabetic foot ulcers and gangrene can be classified as neurogenic, mixed and ischemic [6]. Neurogenic ulcers usually present with warm skin, sensory numbness, dry ulcers, pain insensitivity, and good arterial pulsation in the foot. Patients with neurologic an ischemic ulcer present with hypothermia, which may be associated with resting pain, ulceration or gangrene at the foot margin, and loss of dorsal foot artery pulsation. Ischemic ulcers alone, without neuropathy, are relatively uncommon in such patients.
1.6 Xi’s new clinical classification of diabetic foot [7]: Professor Xi Jiuyi classified diabetic patients into five major types according to different degeneration of tissues such as skin, nerves, tendons, blood vessels and toe bones: skin degenerative skin lesion type, tendon and fascia degenerative necrosis type (tendon gangrene), vascular occlusion ischemic necrosis type, peripheral nerve degenerative paralysis type, and toe and metatarsal bone degenerative atrophy type.
1.7 Other classification methods: For example, according to the degree of lesions and with reference to foreign standards, Professor Li Shiming classified diabetic foot into grade 0 to V. Grade 0: no open lesions on the skin. grade I: open lesions on the skin of the extremity, but the lesions have not yet spread to deep tissues. grade II: infected lesions have invaded deep muscle tissue, but the tendon ligaments have not yet been destroyed. Grade III: Tendon ligament tissue destruction, but bone destruction is not yet obvious. Grade IV: severe infection has caused bone defect, osteomyelitis and bone joint destruction or has formed pseudo-joint. grade V: infection or ischemia of large part of the foot or all of the foot, resulting in severe wet or dry necrosis.
2. Surgical treatment of diabetic foot: The treatment of diabetic foot is firstly to control blood sugar, if combined with hypertension and hyperlipidemia, etc., various related risk factors should be actively treated and controlled. At the same time, neuropathy treatment, anti-infection, vasodilatation, circulation improvement and other treatments are carried out according to the etiology of diabetic foot. However, most scholars agree that if problems such as arterial stenosis or occlusion of the limb can be solved as early as possible with the help of surgical blood flow reconstruction, as well as choosing the appropriate surgical debridement method according to the extent of the ulcer, it will have positive significance in reducing the amputation rate and improving the prognosis of the disease. The commonly used procedures are as follows.
2.1 Artificial vascular bypass: It is mainly performed by using PTFE artificial vessels to bypass the femoral N artery, and is suitable for patients with poor autologous vein conditions, varicose veins or saphenous veins that have been removed. It is generally believed that the 2-year patency rate of superior knee bypass with PTFE artificial vessels can reach or approach 70%-80%, while the patency rate below the knee is very low, only 30%-40%, but the composite bypass with a distal artificial vessel combined with a vein can increase the 2-year patency rate to more than 50% [8].
2.2 Autologous saphenous vein bypass: This includes in situ vein bypass and inverted saphenous vein bypass. It is generally believed that , as long as the saphenous vein is in good condition, it should be the preferred graft material. However, there is a problem of limited access to the autologous vein, which is relatively more invasive and has the potential for complications such as poor wound healing. Most scholars now believe that the long-term patency rate of autologous saphenous vein bypass is better than that of artificial vessels [9C 10].
2.3 Endovascular luminal treatment: endovascular luminal treatment: currently, balloon dilation and stenting are the mainstays. Endoluminal treatment has received widespread attention because of its small trauma and fast recovery. It is now agreed that endoluminal balloon dilation and stent implantation are more effective than arterial bypass surgery for knee lesions in TASC grade A and B, while endoluminal treatment is less effective for T ASC grade C and D [11].
2.4 Autologous hematopoietic stem cell transplantation: It is performed by separating stem cells and endothelial progenitor cells from the patient’s autologous bone marrow blood or peripheral blood and transplanting them into the muscles of the ischemic limbs, so that they can gradually differentiate into new capillaries, promote their vascular regeneration, improve and restore blood flow in the lower limbs, and achieve the purpose of treating lower limb ischemia.
2.5 Local surgical treatment of foot ulcers: The purpose is to establish drainage, remove infected necrotic tissue and dead bone, correct foot deformity, restore foot stability and correct position, reduce the risk of amputation due to ulcers, or preserve limb function as much as possible and reduce amputation cross-section.
2.5.1 Incision and drainage: This is the basic treatment when the diabetic foot is co-infected. The operation often requires more than 1 incision, which should be made as far as possible along the long axis of the foot, avoiding neurovascular structures as much as possible. During the operation, the skin, subcutaneous tissue, tendons and deep tissues need to be inspected, and deep tissue intervals, fascial planes and tendon sheaths need to be probed for infection and the presence of dead bone and sinus tracts, so as to remove dead bone, open the wound and drain it thoroughly.
2.5.2 Proximal interphalangeal arthroplasty: For rapid contracture of the hammertoe with or without ulceration in the interphalangeal or proximal interphalangeal joint. The toe should be checked intraoperatively for the presence of osteomyelitis, which must be removed if present; if the contracture of the intermetatarsal joint is not corrected, the metatarsal bone should be partially removed, and if infection is present the wound should be opened and dressed, with extended suturing after 1 week.
2.5.3 Distal interphalangeal arthroplasty: This is indicated for the treatment of ulcers that occur at the tip of the toe. Two semi-elliptical incisions are made transversely in the distal interphalangeal joint. The incisions need to be deep to the skin, extensor tendons and periosteum and these structures are excised.
2.5.4 Keller resection arthroplasty: This is indicated for the correction of interphalangeal joint ulcers in adult bunions. This procedure can be performed under anesthesia with an ankle nerve block. The difficult part of the procedure is the removal of the root of the phalanx, and care must be taken to avoid severing the long bunion tendon. The advantages of this approach are that local anesthesia is less risky, it improves the range of motion of the metatarsophalangeal joint, decompresses the interphalangeal joint ulcer to facilitate healing, and protects the patient’s ability to bear weight. The disadvantages are reduced bunion plantar flexion force, loss of bunion and toe support, and weakened gait.
2.5.5 Seed osteotomy: used to treat refractory ulcers located under the head of the 1st toe, also used to treat seed osteomyelitis, and also suitable for treating people with elevated plantar pressure neuropathy at the head of the 1st metatarsal. The advantages are the low risk of local anesthesia and the simplicity of the procedure. The disadvantage is the possibility of progression to hammertoe or bunion deformity.
2.5.6 Secondary metatarsal osteotomy: It is indicated for the treatment of refractory plantar keratosis and secondary metatarsalgia where non-surgical treatment has failed. The procedure is controversial due to postoperative complications, such as the possibility of metastatic injury, osseous discontinuity or malunion, and toe displacement.
2.5.7 Metatarsal head resection: for chronic osteomyelitis requiring resection of infected metatarsals; selective metatarsal resection, which serves to decompress plantar ulcers to promote wound healing; 5th metatarsal deformity with painful callus on the plantar or lateral aspect of the metatarsal head. The advantages are that it facilitates primary closure of the wound and rapid return to weight bearing. The disadvantage is the possibility of metastatic injury (callus or ulcer).
2.5.8 Heel drill: for ulcers with small trauma in the heel, exposed heel bone and mild local infection. These ulcers are largely ineffective for conservative treatment and are extremely difficult to heal. The application of drilling allows for the growth of granulation from multiple holes in the bone surface, resulting in eventual coverage of the wound. This method is simple and easy to implement, but there is a risk of osteomyelitis.
2.5.9 Partial heel osteotomy: for large refractory ulcers in the heel combined with or without osteomyelitis. This approach is an alternative option for patients with infrapopliteal dissection, provided that the terminal circulation in the heel is good. This procedure allows for eradication of infection and obtains wound closure and limb preservation.
2.5.10 Toe osteotomy: This includes partial bunion toe osteotomy, bunion toe osteotomy, and radial amputation. It is indicated for recalcitrant toe deformities, osteomyelitis, or recurrent ulceration at the interphalangeal joint or distal toe. Care should be taken in this procedure to create a skin slice to close the wound, most commonly the medial and lateral skin slice, so that the neurovascular structures on each side of the toe are maintained.
2.5.11 Metatarsal transection and midfoot amputation: This is indicated for gangrene of one or more toes, gangrene of the distal foot that does not reach the whole foot, and moderate to severe anterior foot deformities. These amputations have the advantage of being the most successful in terms of preserving limb function, patient satisfaction, and long-term prognosis, and they do not require the patient to have a prosthesis after surgery. However, the prerequisite is relatively good peripheral circulation to facilitate one-stage healing of the postoperative incision.
2.5.12 Tibial amputation and femoral amputation: High level amputation, suitable for total foot infection and necrosis, serious and life-threatening systemic symptoms, and strive to save life by early surgery.
2.5.13 Chinese surgical treatment methods: ① Dragline therapy: applicable to sinus tract formation or pockets of pus. After probing with a silver ball-tipped probe, apply Jiuyi Dan and Baidan on the silk thread and drag the thread back and forth several times to drag the drug into the canal to lift the pus and remove the rot. ②Flushing therapy: Applicable to deeper ulcers or subfascial, intermuscular infection foci connected. Or if the sore is small and the basal pus and rot are not yet exhausted, flushing with Chinese herbal medicine for clearing heat and moist detoxification, or selecting highly sensitive antibiotic solution for short-term flushing of the sore cavity according to the pus culture results; for granulation tissue edema, flushing with 3% saline solution; for neuropathic ulcers with small cavities and deep sores, irrigation with 3% tincture of iodine can be used to promote internal fibrosis and gradual adhesion healing. ③Padded cotton wrapping method: Applicable to those whose traumatic flesh has been exhausted, new flesh is growing, and the surrounding tissue has sinus cavities. After the use of pus removing medicine, the trauma surface pus reduction, no pus decay dirt, pus smear culture suggests no bacterial growth. Cotton pad can be used to press the cavity, and then pressure bandage can be applied to make the affected area tight, so as to promote the adhesion and closure of the cavity wall.
3. Problems and discussion: The treatment of diabetic foot is still in the initial stage in China, and requires joint efforts from many aspects. However, there is no unified understanding on how to combine surgical treatment methods and classification criteria with clinical application, and there are many different methods. Western surgery has a unique advantage in diabetic foot revascularization, but Chinese surgery also has an irreplaceable role in the management of diabetic foot local ulcers, especially in the use of topical medications. With the continuous progress of medical technology, the treatment of diabetic foot is becoming a hot topic of concern for clinical surgeons, but there is still a lack of multicenter, randomized, large sample clinical studies to evaluate clinical efficacy. We hope that with the development of clinical studies, the correct and effective treatment measures can be standardized and popularized, so as to relieve patients’ pain, reduce the disability rate, improve the quality of life, and reduce the economic burden of society and families.
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