Lower Limb Ulcers



Fig. 17.1
Venous stasis ulcer : uneven edges, but well defined; granulation tissue on the wound bed; ocher dermatitis; edema



Pain is a common symptom , but its intensity is variable. However, it is usually milder than those of arterial origin, and it is not affected by the size of the ulcer. In general, its intensity increases during the day, worsening in evening times and during long time orthostatic position, improving after lifting the limb [15].



Medical Imaging


Venous duplex scanning is of little help to establish the diagnosis of venous ulcer, which is clinical in most cases. On the other hand, it is very helpful in defining which venous systems are affected: superficial, deep, and/or communicating. It identifies the anatomical abnormalities such as locating precisely which are the compromised veins and systems, if there is acute or chronic superficial or deep thrombosis and collateral vessels. It also adds functional information, determining if there is reflux and/or obstruction in the venous system, providing fundamental information for the proper therapeutic approach [15].


Treatment


Treatment aims wound healing and prevention of recurrence. The main methods are: compression therapy, oral medications, and surgical intervention [15].


Compression Therapy


Compression therapy is the most frequently single therapeutic approach. It promotes symptoms improvement such as pain or heaviness in legs and prevents lower limb edema or allows its resolution, therefore favoring ulcer healing [15]. The available compression methods are: compression socks, multi wraps, bandages, and pneumatic compression [15]. A systematic review showed that compression with elastic stockings can prevent the recurrence of venous ulcers although not with strong level of evidence [19]. All compression methods are contraindicated in the presence of significant peripheral arterial disease, unless the treatment is authorized by a vascular surgeon , based on the ankle-brachial index [15].


Oral Medications


Medications known as phlebotonic drugs are a heterogeneous group of drugs (e.g., rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, centella asiatica, disodium flavodate, french maritime pine bark extract, grape seed extract, and aminaftone). A systematic review with 44 controlled, prospective and randomized studies, the conclusion was that there is no current evidence of its efficacy in cases of chronic venous insufficiency, requiring more clinical trials [20].


Intervention


Surgical options should be considered in patients with nonhealing venous ulcers despite maximal medical effort. Invasive and surgical options may also be considered in patients who are unable to comply with compression therapy [21]. Nonoperative management of venous ulcer, including compression, elevation, and skin care, is clearly beneficial, such therapy does not correct the underlying pathology [22].

Interventional treatment of superficial venous incompetence can be accomplished by techniques that result in removal, ablation, or ligation of the refluxing venous segment (evaluated by venous duplex ultrasound) [23].

Surgery should be individualized according to the patient’s preoperative evaluation. A combination of ligation, axial stripping, and stab phlebectomy may be applied as needed to the great saphenous vein, small saphenous vein, tributary veins, and perforating veins [23].

A systematic review showed that open surgery can improve healing of venous ulcers, but the level of evidence is low, since the comparison was with observational studies [24].

The approach of deep venous system is more complex and includes techniques such as valve repair, valve transplantation, and venous shunts. The recommendation and the results of these techniques are highly controversial, and they are not routinely indicated in daily practice [15].

Endovenous minimally invasive techniques include: (a) endovenous laser and radiofrequency ablation, which promote physical damage to the saphenous vein, occluding it; (b) ultrasound-guided foam sclerotherapy, which promotes chemical occlusion of varicose saphenous and other veins and leads to correction or reduction of venous pressure, allowing the healing of ulcers [15]. Current evidence does not show superiority of endovascular interventions when compared to the isolated compression therapy [24].



Arterial (Ischemic) Ulcers



Concept


Arterial ulcers are caused by the lack of tissues oxygenation secondary to arterial obstruction of the lower limbs. The most common cause is atherosclerosis in about 90 % of cases [25].


Epidemiology


Prevalence of peripheral arterial disease in the United States is estimated at 3–5.5 %, and rises to 10–18.2 % in the population over 70 years of age [26]. Of these, 1–3 % will have peripheral ulcer throughout lifetime [27]. Arterial ulcers account for about 4–10 % of lower limb ulcers. The incidence increases to almost 20 % if mixed ulcers are included [2, 10, 28]. Studies show that these patients have a risk of major limb amputation ranging from 25 to 40 % after 1 year if not revascularized [29, 30].


Pathophysiology


Decreased arterial blood flow leads to ischemia and impaired tissue perfusion. At first, manifesting only during exercise (intermittent claudication). With the progression of the disease, this poor perfusion occurs even at rest, leading, in advanced stages, to necrosis of the underlying dermis and other tissues [25, 31].


Clinical Presentation


The intense pain draws attention in arterial ulcers . Its intensity increases after raising the foot, improving with the use of potent painkillers or keeping the foot down [25, 30, 32].

Ulcers can occur spontaneously or after minor local trauma. It is manifested with necrosis, without granulation tissue (Figs. 17.2 and 17.3). The wound bed is pale, dry, and the edges are irregular [27]. In the presence of secondary infection, there is humidification of necrotic and surrounding tissues, with exudative secretion and stench, condition called wet gangrene [33].

A340688_1_En_17_Fig2_HTML.jpg


Fig. 17.2
Gangrene restricted to left forefoot saving the fifth toe


A340688_1_En_17_Fig3_HTML.jpg


Fig. 17.3
Gangrene restricted to left forefoot saving the fifth toe

Unlike venous stasis ulcers, arterial ulcers are typically located below the ankle, usually at the distal parts like toes and forefoot [34]. Another common presentation is in bedridden or immobilized patients who develop pressure ulcer in areas of unrelieved pressure, especially in heels [33, 35], but can occur anywhere else in the foot after a local trauma. They can be shallow or deep, with involvement of tendons, muscles, and bones. Arterial ulcers do not heal due to insufficient blood supply. The patient may have other signs of chronic ischemia, such as low skin temperature and reduced peripheral perfusion, thin, pale, and dry skin with no hair and nail dystrophy associated [25, 33].

Diagnosis is clinical. Physical examination shows absence of palpable pulses in the limb. For the objective confirmation of the disease, the ankle-brachial index must be performed, and it is usually under 70 mmHg [27, 36].


Treatment


Treatment of arterial ulcer is complex and leaded by the vascular expert. These ulcers often require restoration of blood flow for wound healing and pain relief. Patients with atherosclerotic arterial ulcers should have medical treatment for systemic atherosclerosis: smoking cessation; strict control of blood pressure, glucose, and cholesterol levels; and use of antiplatelet drugs and statins [37]. Arterial revascularization can be performed by open surgery (artery bypass grafting) or endovascular surgery (percutaneous intervention) [38]. In patients with extensive trophic lesions or impaired limb functionality or those who, for medical reasons, are not candidate for revascularization, primary limb amputation can be the definitive and effective treatment [32]. The WIFi classification, based on wound characteristics, degree of ischemia and infection, helps to establish the risk of amputation and which patient will most benefit with revascularization [39].


Mixed Ulcers


Once the prevalence of chronic venous insufficiency is high in the population, as well as atherosclerosis and its consequences, it is not rare to find ulcers with simultaneous venous and arterial involvement. It is estimated that they affect more than 26 % of lower limbs ulcers [10, 40].

At ectoscopy, signs of chronic venous insufficiency prevail, such as dermatosclerosis, ocher dermatitis, ankle ankylosis, and white atrophy; but at physical examination the peripheral pulses are absent and the ankle-brachial index is lower than 0.9 [10, 41]. Mixed ulcers have features that vary from the aspect of venous ulcers and arterial ulcers, depending on the severity of the arterial component [41].

Patients with mixed ulcers may benefit from limb revascularization surgery [42]. In cases where there is no indication of revascularization, the treatment should proceed the same way as for venous ulcers, with the exception that the compression therapy may be contraindicated, due to the risk of worsening peripheral perfusion. In addition, patients might also not tolerate resting with the lifted limb. These are limiting factors in the treatment of these ulcers [40].


Hypertensive Ulcers


Hypertensive ulcers , also known as Martorell ulcers, are infrequent ischemic vascular ulcers, resulting from a severe and poorly controlled systemic hypertension. It is more common in women between 50 and 70 years of age [43].

High blood pressure leads to arteriolar vasospasm and subsequent skin infarction, leading to ulceration. They are mainly located in the distal third and the anterolateral aspect of the leg, and they are extremely painful. Since there is no macrovascular disturbance, peripheral pulses are commonly palpable. The blood pressure is usually very high. Control of pain and blood pressure levels is the mainstay of treatment [44].


Neuropathic Ulcers


Neuropathic ulcers may occur in patients with loss of sensation in legs and feet, such as in diabetes, Hansen’s disease, spinal cord injury, and other conditions. The most common ones are those of diabetic foot (described in Chap. 11). About 25 % of people affected by diabetes will develop foot ulcers [15]. About three million people are affected by Hansen’s disease worldwide, and the incidence of neuropathic ulcer due to this condition is more common in India [45]. Patients with such diseases lose limb sensibility due to sensory neuropathy over time, so they are unable to feel pain while using inappropriate shoes or hitting objects on the ground when walking, for example. Thus, sensibility is protective, and those patients may develop ulcers without noticing it [46].

Neuropathic ulcers usually occur through injury and destruction of deep tissues associated with neurological abnormalities and various degrees of peripheral vascular disease in the lower limbs, due to the continuous mechanical pressure in a specific area [47], normally the plantar aspect of the foot [45, 46].

Neuropathic ulcers are painless and have a hyperkeratosis halo; being an important gateway to infections. The most frequent location is the plantar surface and the metatarsal heads. Classically neuropathic ulcers have well-defined edges, with depth varying according to the severity and duration of lesion, the presence of necrosis and exudate [45, 47]. The skin around the wound may show calluses, erythema, and maceration. Pulse is generally palpable, but it may be incompressible according to the severity and duration of the disease [45, 47].

Diagnosis is done on clinical basis. Evaluation of associated peripheral artery disease is necessary through the ankle-brachial index or transcutaneous oximetry, the latter recommended in case of diabetes and elderly patients. The application of WIfI (Wound, Ischemia, and foot Infection) classification is very important to evaluate prognosis for major amputation in a year and the benefits of limb revascularization for diabetic patients [39].

Treatment of neuropathic ulcers is based on multidisciplinary care, on control of underlying diseases and wound care, using appropriate dressing and offloading on the area, with the use of special shoes or with frequent position changes, seeking to reduce plantar pressure with use of appropriate footwear and individualized to distribute pressure. Age [45] also states about the importance of health education to prevent recurrence, deformity, and amputation [48].


Other Less Common Causes of Ulcers





  1. 1.


    Vasculitis and collagenosis: group of diseases such as systemic lupus erythematosus, rheumatoid arthritis, and thromboangiitis obliterans, in which the blood vessels are compromised by inflammation. One percent of all the ulcers belong to this group. Location is variable, there may be skin and toes necrosis, and it may be accompanied by purpura, reticular livedo, and white atrophy. The pain ranges from moderate to strong and intensity does not modify with position changing. Treatment depends on correct diagnosis and consists in treating the underlying disease, suppress inflammatory response, and prevent the deposition of immune complexes. Corticosteroids and immunosuppressive drugs are required [49, 50].

     

  2. 2.


    Neoplastic ulcers : primary skin tumors rarely affect the lower limbs. The malignant transformation of a chronic ulcer of another etiology is less unusual, though. They normally have high edges and are located in areas of scars or previous chronic ulcer [49].

     

  3. 3.


    Hematological ulcers: eight to ten percent of homozygous patients for sickle-cell disease and alpha-thalassemia may present leg ulcers. They are located preferably at the medial malleolus area, with high edges, are deeper and often involve muscle fascia, and may contain necrotic tissue. They are usually very painful, bilateral, and tend to chronicity. Systemic symptoms such as malaise, weakness, arthralgia, and fever are ordinarily present [51, 52].

     

  4. 4.


    Infectious and parasitic ulcers: many agents can cause ulcers, such as bacteria, viruses, fungi, protozoa, and parasites. Some of the most common are:


    1. (a)


      Cutaneous leishmaniasis, zoonotic disease caused by protozoa of the genus Leishmania. The typical ulcer is oval and presents with high and infiltrated edges, with bright red background and it can be covered with exudate. Usually, they are unique and can be present in various parts of the body [5355].

       

    2. (b)


      Cutaneous tuberculosis manifest as erythema induratum of Bazim, then liquefy and form a fistula, with consequent formation of ulcer. It is usually located on the back of the thigh and leg. Treatment of cutaneous tuberculosis is the same as systemic tuberculosis [56, 57].

       

     

  5. 5.


    Hansen’s disease, caused by Mycobacterium leprae, affects skin and peripheral nervous system. Ulcers may be correlated to necrotic erythema nodosum or peripheral neuropathy (neuropathic ulcers). They can commit large areas of the leg [54].

     

  6. 6.


    Ecthyma is a primary pyogenic infection that leads to ulceration of the skin. It is caused by streptococcus or staphylococcus infections and is more common in the pediatric population. It starts with a vesicle or a pustule that forms an ulcer and may present a bonded crust. It is treated with antibiotics as cephalexin, oxacillin, erythromycin, or azithromycin [5860].

     

  7. 7.


    In metabolic diseases, such as porphyria, ulcers can appear in sun-exposed areas [49, 50]

     

  8. 8.


    Other: pyoderma gangrenosum may cause ulcer, but pathophysiology is unknown. Half of the cases are associated with chronic diseases such as ulcerative colitis, Crohn’s disease, rheumatoid arthritis, and cancer. The other half is considered idiopathic. Typical lesions are painful pustules with rapid progression to ulceration and necrosis. They can affect any part of the body. The treatment can be done by intralesional or systemic corticosteroids [49, 50, 61].

    For proper treatment of the lower limb ulcers, it is important to be aware of the wide variety of differential diagnoses [10, 62].

     


Topical Treatment of the Ulcers


Topical treatment consists in the use of dressings and local agents, and this is only a part of the treatment. It must be stressed that the cause of the ulcer should be treated and interdisciplinary monitoring is required. Thus, associated with the identification of the cause and institution of specific treatment for the underlying disease, local wound care should be initiated [63].


  1. 1.


    Wound cleaning : only nontoxic products should be used [64]. Some studies recommend that the wound must be cleaned with saline solution 0.9 %, since it exhibits the same pH of plasma and does not interfere in the cicatrization process [64]; but systematic reviews concluded that good quality drinking water can also be used for cleaning wounds, if used cautiously [65]. Cleaning must be done with high pressure in continuous or intermittent flow. The applied pressure should go from 8 to 12 lb per square inch (psi), which is enough to remove devitalized tissue and bacteria. Wound cleaning newer systems use pressurized saline solution through a nozzle, between 12,800 and 15,000 per square inch (psi) [66].

     

  2. 2.


    Debridement : it must be done when there are unviable tissues such as necrosis or excessive fibrin, or signs of infection (exudate, pus, skin redness) to allow the formation of granulation tissue and appropriate epithelialization. To perform the debridement, there is a wide range of methods, including [66]:


    1. (a)


      Autolytic : natural process that promotes the maintenance of moist environment through the use of dressings and topical agents. Many of these dressings moisturize and remove necrotic tissue and slough (e.g., hydrogel and Petrolatum Gauze Non-Adhering Dressing) [66];

       

    2. (b)


      Enzymatic : use of ointments with enzymatic action , such as collagenase, fibrinolysin, deoxyribonuclease, and papain. The disadvantages are the need for frequent dressing changes and debridement at a slow rate [66].

       

    3. (c)


      Surgical: consists in aggressively excising the devitalized tissue using surgical techniques. The disadvantages are: hospital facility are needed, anesthetic use is demanded with its associated complications, requires some time of procedure, and may cause pain, bleeding, and healthy tissue excision [66].

       

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Sep 30, 2017 | Posted by in CARDIOLOGY | Comments Off on Lower Limb Ulcers
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