Lymphedema of the extremities

Introduction to limb lymphedema Lymphedema refers to the blockage of lymphatic fluid due to defects in the lymphatic system in certain parts of the body, which causes reflux of body fluids in the soft tissues of the limbs, secondary fibrous hyperplasia, fatty sclerosis, thickening of the fascia and thickening of the entire affected limb. Pathological state. The basic factor of lymphedema is the retention of lymph, and the initial cause of lymphatic retention is the obstruction of the lymphatic return channel. Some scholars call lymphedema "low-output failure." basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: malnutrition

Causes of lymphedema in extremities

(1) Causes of the disease

Lymphedema is a general term for the clinical symptoms or signs of a systemic disease manifestation. The multi-source of the etiology and the complexity of the pathogenesis determine that it is difficult to classify it into simple categories. Did not solve the classification problem well, and even confounded congenital or acquired lymphedema and infectious lymphedema, resulting in unclear concept, limb lymphedema can be divided into primary lymphedema and secondary lymphedema 2 Large categories, and then, according to the specific cause of further classification, it is worth mentioning that, in many patients with clinical lymphatic edema, congenital lymphatic development defects can be combined with acquired trauma or infection factors to promote lymphedema.

1. Primary lymphedema:

(1) Congenital lymphedema: a family history of congenital lymphedema, known as Nonne-Milroy disease, has lymphedema symptoms at birth, and these patients account for 10% to 25% of all cases of primary lymphedema And more common in women, female cases are more than twice as many as males; lower limbs are more than upper limbs, the incidence ratio of upper limbs to lower limbs is 1:3, except for the extremities, the external genitalia, small intestine, lungs can be involved; It is related to congenital malformations in other parts, and the molecular biological basis of its developmental disorders is unknown. The mechanism of lymphatic stasis is also lack of in-depth discussion.

(2) Congenital lymphatic overgrowth: This type of lymphedema is usually diagnosed when the child is 5 to 10 years old, but the history of the disease is often found to have mild edema after birth. The cause of lymphatic stasis may be due to the location of the chyle. Obstruction, but there is still no objective basis, the clinical manifestations of the whole lower limb or bilateral lower extremity swelling, but rarely concurrent infection, it is different from other types of lymphedema is characterized by thickening and increasing the number of subcutaneous lymphatic vessels, these lymphatic vessels Expansion, distorted and valvular insufficiency, chyle reflux is common, histological examination can be found in the enlarged lymphatic muscle layer thickening.

(3) early onset and delayed lymphedema: such cases account for 80% of all primary lymphedema, early onset lymphedema is more common in women, age of onset is 20 to 30 years old; delayed lymphedema After 35 years of age, edema first appeared around the instep and ankle joints. About 70% of patients had edema in the unilateral lower limbs. Lymphedema developed over several months or years and spread throughout the calf, while edema rose to the thigh but was rare. Usually, such lymphedema tends to be stable after a few years of onset, and the course of the disease progresses slowly. About 30% of the contralateral limbs are involved after several years after the edema of the primary limb. These patients are rarely accompanied by acute episode dermatitis and Lymphangiitis, histological examination showed thickening of the intima of lymphatic vessels and draining lymph nodes, collagen deposition under the intima, muscle fiber degeneration, suggesting inflammatory pathological changes, early onset lymphedema and delayed lymphedema in addition to the onset time There is no difference in substance.

2. Secondary lymphedema:

The causes of secondary lymphedema can be summarized as follows:

(1) Traumatic or injurious: The cause includes iatrogenic lymph node biopsy and blockade of the lymphatic drainage pathway after resection. Clinically common groin, axillary lymph node dissection caused by limb lymphedema, any type of Trauma factors, including burns, especially in the bilateral axillary and groin areas, and large-scale scar formation, can lead to limb lymphatic drainage disorders, which induce lymphedema.

(2) Infection or inflammation: Infection and inflammation are important factors that cause lymphatic vessel morphology and dysfunction. Long-term limb chronic eczema, foot and its complicated bacterial infection can easily lead to skin laceration, and streptococcus and staphylococcus invade through the gap. Limbs, if not treated properly, can cause recurrent episodes of lymphangitis, high fever, swelling of the limbs, and finally decompensated lymphatic drainage to cause limb lymphedema.

(3) Filaria Infectivity: Filariasis is a nematode infection. Before the 1950s, it was prevalent in China, especially in the south of the Yangtze River. Lymphatic system is one of the important invasive parts of filarial infection. Although China has eliminated filamentous worms Disease, but the number of patients with lymphedema caused by filarial infection is still a lot.

(4) malignant tumor and lymphedema after radiotherapy: radical mastectomy can cause upper limb lymphedema; pelvic tumor, penile cancer and other surgical resection, local lymph node dissection or postoperative radiotherapy, are easy to concurrent with lower extremity lymphedema, Hodgkin's disease can also cause lymphedema of the limbs. This is because lymphoma cells invade the lymphatic vessels and lymph nodes, causing blockage or destruction of the lymphatic pathway. Lymphosarcoma and AIDS are also common because of their major invasion of the lymphatic system. Lymphedema is characterized by edema from the proximal end of the limb and then to the distal end. Lymphatic imaging can show the obstruction, which is helpful for clinical diagnosis. Tumor-induced lymphedema often has a clear history, such as surgery and radiotherapy. History, but should not ignore the early lymphedema edema performance of some tumors, and the best time to delay the treatment of tumors, the classification of 1043 cases of limb lymphedema diagnosed early in Shanghai Institute of Veterinary Surgery, Shanghai Second Medical University The following are: 112 cases of primary lymphedema (10.74%); 931 cases of secondary lymphedema (89.26%) Among them, 487 cases (46.69%) were infected, 287 cases (27.52%) were filarial, 78 cases (7.48%) were traumatic, 53 cases (5.08%) after operation, and 26 cases (2.49%).

(two) pathogenesis

The basic factor of lymphedema is the retention of lymph, the initial cause of lymphatic retention is blocked by lymphatic drainage channels. Some scholars call lymphedema as "low-output failure", which is different from the increase of lymphogenesis and lymphatic load overload. Caused by tissue edema, such as hypoproteinemia, venous embolism, lower extremity arteriovenous fistula, etc., the latter is also known as "high-output failure", because the initial factors of such edema occur outside the lymphatic system, lymph Relatively insufficient output function is the result of elevated venous pressure and excessive exudation of water and protein. Such edema does not belong to lymphedema.

From an anatomical point of view, lymphatic drainage disorders can occur in all levels of lymphatic pathways, such as the initial lymphatic vessels, dermal lymphatic network, collecting lymphatic vessels, lymph nodes, chylothorax and thoracic ducts, which are caused by different sites of lymphatic obstruction. The pathophysiological changes of lymphedema are also different. For example, the pathophysiological changes in the pelvic large lymphatic vessels are completely different from the initial lymphatic occlusion. In addition, different pathogenic factors such as trauma, infection, radiation, etc. Lymphatic lesions are also different, and the cause of primary lymphedema such as Nonne-Milroy is unclear.

The pathological process of chronic lymphedema is divided into three stages: edema stage, fat hyperplasia stage and fibroproliferative stage. In the early stage of the disease, lymphatic reflux is blocked, lymphatic pressure is increased, lymphatic vessels are dilated, twisted, valve function is gradually lost, lymph fluid Reflux affects the ability of the capillary lymphatic vessels to absorb interstitial fluid and macromolecular substances, causing body fluids and proteins to accumulate in the interstitial space. The lymphedema of the lower limbs begins to swollen from the ankle, gradually expanding from the bottom to the top, and the limbs are uniform. Thickening, the lower third of the ankle and lower leg, at this time the skin is still smooth and soft, there is depression edema when acupressure, after raising the limb to rest in bed, the swelling can be significantly subsided, this stage belongs to lymphedema The edema persists. Under the stimulation of lipid components, macrophages and fat cells phagocytose lipid components in the lymph, subcutaneous fat tissue proliferate, limb toughness increases, skin keratinization is not obvious, and edema transitions to non-depression Lymphedema enters the stage of fat hyperplasia. The tissue swelling at this stage mainly includes stasis of lymph and hyperplastic adipose tissue. Under the long-term stimulation of white components, the skin and subcutaneous tissue produce a large amount of fibrous tissue, and the lymphatic wall is gradually thickened and fibrotic, so that the tissue fluid is more difficult to enter the lymphatic vessels, and high protein edema is further aggravated. The high protein edema fluid is a microorganism such as bacteria. Good medium, local infection is easy to induce, erysipelas recurrent, infection increases local tissue fibrosis, aggravates lymphatic obstruction, forms a vicious circle, called fibroproliferative phase, clinically shows that the skin is gradually thickened, the surface is excessively hyperkeratotic Hard as a skin, even sputum hyperplasia, lymphatic or ulcers, limbs extremely thick, forming a typical elephantiasis.

Limb lymphedema prevention

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Limb edema complications Complications malnutrition

Limb lymphedema with its characteristic non-recessed edema and advanced tissue fibrosis caused by skin, subcutaneous tissue like skin-like combined with lymphography and lymphatic imaging clinical diagnosis is generally not difficult, but edema as a symptom and signs, more A variety of diseases can be caused, involving multiple clinical departments, in the diagnosis of lymphedema should still be differentiated from a variety of diseases.

1. The bilateral limb edema should first be distinguished by lymphedema caused by accumulation of lymph with high protein content, or edema caused by accumulation of body fluid with low protein content such as cardiac hepatic, renal, dystrophic and other systemic edema. And localized venous or neurovascular edema, which can generally be identified by medical history, physical examination and laboratory tests.

2. Unilateral limb edema should be distinguished from venous disease. Limb edema caused by venous disease is usually characteristic.

Symptoms of lymphedema in extremities Common symptoms Lymphatic hypoplasia Occupational edema of the sacral edema of the limbs Non-concave edema of the anterior acupressure edema of the anterior and foot of the foot... Cervical lymphadenopathy, leg edema, traveller edema, rough skin fatigue

The clinical manifestations of limb lymphedema are persistent or progressive swelling of the unilateral or bilateral limbs. The edema is depressed after the early pressing of the skin. It is also called depression edema. At this time, if the limb is continuously raised, the edema can be alleviated or subsided. If it is not treated in time, the condition will gradually progress, and the skin may become rougher and stiffer, and the elasticity will be weakened and disappeared. The depressed depression will also become less obvious when it is weakened. Currently, it is generally based on limb edema. The extent of secondary lesions divides lymphedema into 4 stages.

Stage I lymphedema: limbs are mild, moderately swollen, with no limb fibrosis or only mild fibrosis.

Stage II lymphedema: local edema and fibrosis were obvious, and the affected limbs were significantly thickened, but the circumference of the limbs was less than 5 cm.

Stage III lymphedema: local edema and fibrosis were obvious, the affected limbs were significantly thickened, and the circumference of both limbs was more than 5 cm.

Stage IV lymphedema: severe advanced edema, extremely fibrotic skin tissue, often accompanied by severe limb keratosis and thorny formation, the entire limb is abnormally thickened, shaped like elephant legs, also known as elephantiasis.

Examination of limb lymphedema

Including differential white blood cell count, eosinophils in filariasis, peripheral blood smears can be found in Wu Ceban, plasma protein, total protein, electrolytes, renal function tests, liver function tests, urinalysis, etc. can help Exclude other causes of limb edema.

1. Diagnostic puncture :

Diagnostic puncture examination is helpful for the identification of deep hemangioma and venous edema. The procedure requires only a syringe and a needle. The method is simple, but the location and function of the lymphatic vessels cannot be understood. The protein content of lymphatic edema fluid is usually very high. In 10 ~ 55g / L (1.0 ~ 5.5g / dl), and venous stasis, cardioembolic edema and hypoproteinemia edema tissue protein content of 1 ~ 9g / L (0.1 ~ 0.9g / dl).

2. Lymphangiography :

Lymphangiography is a method of injecting contrast agent directly or indirectly into the lymphatic vessels to develop a radiograph and observe the morphology and reflux function of lymphatic vessels. It is divided into direct lymphangiography and indirect lymphangiography. The agent remains in the lymphatic vessels, combined with lymphatic drainage disorder, and the contrast agent causes secondary damage to the lymphatic vessels. Therefore, most people now do not advocate lymphangiography.

(1) Direct lymphangiography: firstly use reactive dyes such as 4% methylene blue, 2.5% to 11% acid lake blue, 0.5% to 3% Evans blue to the skin of the finger (toe), and then guide The skin was cut at 5 cm near the injection point, and the lymphatic tube under the dermis was found. Under the operating microscope or magnifying glass, the needle was inserted into the lymphatic vessel with a diameter of 0.3-0.35 mm, and the iodine was slowly injected into the ligation. Tablets, contrast agent spillover or lymphatic vessels are stimulated to cause inflammatory reactions, routine use of antibiotics after surgery, and raise the affected limbs, pay attention to rest.

(2) Indirect lymphangiography: an imaging method in which a contrast agent is injected into the body and absorbed by the lymphatic vessels. The contrast drug developed in the early stage is highly irritating, the drug absorption is unstable, the development is irregular, and the blood vessel image is Confusion, failed to promote clinical application, the emergence of a new generation of contrast agent Aesop in 1988, the clinical application of indirect lymphangiography.

The contrast method is to inject the contrast agent into the subcutaneous space of the toe. After 2 to 3 minutes, the lymphatic vessels are filled, the contrast agent spreads to the heart, and the lymphatic vessels are gradually developed. Generally, about 10 minutes after the injection, the inguinal lymph nodes have been developed and observed.

Normal lymphatic angiography can see a small tube of 0.5 ~ 1mm, the caliber is the same, the corrugated shape, the spindle is 1cm apart, the position of the lymphatic valve, the lesion, regardless of primary or secondary lymphedema, Can show the following performance:

1 The number of lymphatic vessels is reduced, or not developed, or only the distal lymphatic vessels are seen, which may be congenital lymphangiogenesis or secondary occlusion of the lymphatic vessels, which cannot be developed.

2 lymphatic hyperplasia, distortion, dilatation, valve failure, intradermal reflux, or lymphatic vessel interruption, etc., mainly secondary lymphedema, proximal lymphatic blockage, also seen in a small number of primary lymphedema.

3. Radionuclide lymphography :

After the macromolecular radioactive tracer is injected into the interstitial space, it enters the lymphatic vessel and is almost completely removed by the lymphatic system. The imaging device can display the pathway and distribution of lymphatic reflux and the dynamic changes of lymphatic reflux. Nuclide is used clinically. The most commonly used is 99mTc-Dextran. After injection of nuclide between the toes, the static images are scanned at 1/2h, 1h, 2h and 3h.

Radionuclide lymphography can clearly show the lymph nodes and lymph nodes of the limbs, and can show lymphatic reflux, but once the radionuclide enters the blood circulation, it is quickly taken up by the liver, spleen, lungs and other organs, affecting the mediastinal lymph nodes of the upper abdomen. The dry display, radionuclide lymphography method is safe, simple and easy to perform, reproducible, patients without pain, can be used for comparison before and after treatment, is currently the most valuable diagnostic method for limb lymphedema.

Diagnosis and differential diagnosis of limb lymphedema

Diagnostic points

According to the medical history and clinical manifestations, the diagnosis of lymphedema is generally not difficult. The clinical manifestations of different causes may be slightly different, but they also have in common: 1 soft depressed edema that begins and gradually increases from the ankle, lasts for several months, no With other symptoms, it is the characteristics of the disease; 2 the increase in limb diameter increases the weight of the limb, the patient often complains about limb fatigue; 3 as the subcutaneous fibrosis progresses, the limb becomes hard and develops into non-recessed edema, and finally the skin becomes hard and Keratinization.

Limb lymphedema with its characteristic non-recessed edema and advanced tissue fibrosis caused by skin, subcutaneous tissue like skin-like changes, combined with lymphography and lymphatic imaging, clinical diagnosis is generally not difficult, but edema as a symptom and signs A variety of diseases can be caused, involving a number of clinical departments, in the diagnosis of lymphedema should still be differentiated from a variety of diseases.

Differential diagnosis

1. The bilateral limb edema should first be distinguished by lymphedema caused by accumulation of lymph with high protein content, or edema caused by accumulation of body fluid with low protein content such as heart, liver, kidney, malnutrition, etc. Edema and localized venous or neurovascular edema, which can generally be identified by medical history, physical examination and laboratory tests.

2. Unilateral limb edema should be distinguished from venous disease. Limb edema caused by venous disease usually has characteristic skin atrophy and deep pigmentation and long-term venous stasis, which is easier to distinguish from lymphedema and blood vessels. Contrast is also an effective means of distinguishing between venous and lymphedema, but it should be noted that most of the limb swelling caused by late venous obstruction or poor reflux has lymphatic drainage disorder, and the appearance of lymphatic reflux disorder will aggravate venous reflux disorder. It should be taken seriously when handling.

3. Female patients should be distinguished from fat edema when limb edema occurs. Fat edema is a rare disease that affects women. This fat metabolism disorder is characterized by diffuse, symmetrical, non-depressed limbs. Subcutaneous tissue increased, but its lymphatic imaging showed no abnormalities in lymphatic and lymphatic drainage.

4. Some patients with lymphedema have a short history and obvious limb swelling in a short period of time. They should be alert to the possibility of pelvic tumor metastasis, such as cervical cancer, metastasis of prostate cancer to the axillary lymph nodes, obstruction of the limb lymphatic vessels, or simultaneous compression of the iliac vein. Severe lymphedema should be noted in the diagnosis.

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