NOSOLOGICAL DEFINITION AND CLINICAL PICTURE
Lipedema can be defined as a volumetric increase, typically located in the lower limbs, bilateral, symmetrical, of soft consistency, which develops with the accumulation of adipose tissue, in a similar way to "riding breeches", ie starting from the hips arriving to the level of the ankles. Lipedema is a nosological entity with an unknown etiology that predominantly affects the female sex. According to recent epidemiological studies, it manifests itself in 11% of the female population: it frequently starts at menarche, menopause, or during pregnancy.
Although there has been a low incidence in males, cases characterized by a significant alteration of male sex hormones and / or disorders of liver function have been reported. In particular, some authors point out the existence of an increased incidence following cranial traumas and subsequent surgical interventions for pituitary adenomas.
Lipedema can have an ascending or descending development. The phenomenon usually begins at the hips and thighs, with an increasing progression to the lower limbs. The typical sign constituted by the edemato-fibrosclerotic panniculitis appears, however, later. In advanced cases, especially in untreated elderly subjects, subcutaneous nodular formations can be found, as a result of sclerotic processes affecting the subcutaneous connective tissue. In severe cases, immobility is the direct consequence of elephantiasis in the lower limbs. The color of the skin is usually normal, except in cases where the lipedema is associated with a particular form of erythrocyanosis (erythrocyanosis crurum puellarum). In some cases, hemispherical fat pads are evident medially at the knee joint. Occasionally lower limb lipedema is accompanied by upper limb lipedema and typically the swelling develops from the shoulder terminating near the wrist. In rare cases, on the other hand, lipedema affects exclusively the upper limbs.
We can also distinguish other significant aspects that define lipedema.
- Often the edematous fluid accumulates in the affected limb, in particular in the hot periods and in the second half of the day. In the lipedematous region, a soft consistency is appreciable upon manual compression. This pressure does not cause a painful sensation to the healthy person or to the patient with lymphedema, while it provokes a painful sensation in the patient with lipedema.
- A minor trauma that normally does not leave traces in normal tissue can, on the contrary, cause ecchymosis in the lipedematous region, for example, hematomas located in the subcutaneous adipose tissue.
- Frequently lipedema causes a strong state of emotional stress: the patient feels unpleasant and deformed, a condition that negatively affects the quality of life and can cause consequent depression in these subjects, which leads to further complications.
Adipose tissue is a particular type of connective tissue consisting of adipose cells (adipocytes) which, by grouping together, form lobules separated by fibrous septa of connective tissue. Every single adipose cell has its own blood support guaranteed by a capillary system and its own innervation mediated by adrenergic nerve fibers. It is also claimed that the adipose tissue has sensory innervation. Lymphatic capillaries can be detected at levels of the fibrous septa, but not between the adipocytes. The few reticular fibers between the fat cells constitute the initial (or prelymphatic) lymphatic drainage system.
Microangiopathy, which develops in the area of adipose tissue, causing an increase in protein permeability and, likewise, an increase in capillary fragility, is one of the initial mechanisms that characterises lipedema. As a consequence of the increase in permeability, accumulation of liquid with a high protein content occurs in the surrounding cellular area, while as a consequence of the increase in capillary fragility, typical bruising appears.
The soft consistency of adipose tissue can be associated with a neurogenic inflammatory state, which further complicates the condition of microangiopathy. Some scholars are of the opinion that this extremely soft consistency is linked to damage to the autonomic nervous system. According to this theory, this alteration could lead to erroneous interpretation of the protopathic sensory inputs (linked to pressure, temperature, or posture) and this is known, for example, in Sudeck-Leriche syndrome.
The pericellular accumulation of liquid is associated with dilatation of the prelymphatic drainage system, with the result that the liquid flows very slowly through the initial lymphatic vessels. At the level of the skin, typical pathological changes are appreciable in the lymphatic capillaries. In particular, the permeability of the capillary wall is markedly increased and some studies, characterized by the use of fluorescent microlymphangiography, have shown some aneurysmal-like formations in association with numerous capillary segments of extremely reduced caliber.
In this way, it is possible to understand how dilation of the prelymphatic channels, together with morphological and functional alterations of the lymphatic capillaries, gives rise to progressive damage to the lymphatic drainage capacity.
In addition to this, a disturbance of the motor activity of the lymphangion (which represents the anatomical-functional unit of the lymphatic collector, ie the segment interposed between a valvular apparatus and the other segment) has been observed. Early pictures, highlighted by the use of lymphangiographic examination with oil contrast, have shown the presence of suprafascial lymphatic collectors in a corrugated form, so-called "corkscrew". In cases associated with elephantiasis, the condition of progressive immobility exerts a detrimental effect on the formation of lymph and the motor activity of the lymphangion. Furthermore, isotopic lymphography demonstrated accelerated aging of the lymphatic pump.
In lipedema, skin elasticity is greatly reduced, while skin "compliance" (hardness index, expressed in mmHg, measured by tonometer) is increased. This has serious consequences:
- The skin loses its role as a ‘help’ to the venous pump of the lower limbs. In healthy subjects, in an upright position, the pressure in the veins of the back of the foot is 100 mmHg; during walking this pressure drops to 30 mmHg. This mechanism does not work properly in patients with lipedema and the resulting passive hyperemia leads to a high volume of ultrafiltration. Due to the increased "compliance" of the skin, a larger volume of interstitial fluid is needed to increase the interstitial pressure. In this way the lymph drainage function is further compromised and, consequently, an important passive defense mechanism against the development of edema is lost.
- Another significant aggravating factor is the fact that the venous-arteriolar reflex is absent. Normally, in healthy subjects, this reflex involves vasoconstriction in orthostasis: the resulting reduction in the perfused capillary area in turn reduces the volume of ultrafiltrate in the lower limbs. Therefore this reflex, missing in the lipedema, represents a relevant defense mechanism against the establishment of edema.
- In adipose tissue, macrophages able to eliminate plasma proteins outside the lymphatic vessels are rarely found. For this reason, fibrosis develops rapidly among the adipocytes and collagen fibers appear.
In lipedema, pitting edema (fovea sign) often develops in the second half of the day during the more temperate seasons. The reason for this is related to the fact that heat leads to the development of reactive hyperaemia which, in turn, increases the lymphatic fluid load. If edema associated with water retention occurs with lipedema, the lymphatic vascular insufficiency becomes manifest. This is because a good function of the valvular system of the lymphatic system promotes good lymphatic drainage and prevents gravitational reflux. Therefore, in lipedema, on one hand the lymphatic, water, and protein loads are increased, lymph formation and the motor activity of the lymphangion are altered, and on the other side the valvular apparatus of the lymphatic system is seriously insufficient.
COMPLICATIONS AND ASSOCIATION WITH OTHER PATHOLOGIES
Complications related to the patient:
- Anorexia nervosa
Complications related to doctors:
- Diuretics / laxatives missuse
- Sclerotherapy (telangiectasia)
- Varicose surgery without absolute indication
- Gastric banding, gastric bypass
- Lipedema + idiopathic cyclic edema syndrome
- Lipedema + arthrosis
- Lipedema + chronic venous insufficiency
It should be emphasized that lipedema is not just a "subjective problem" of the patient, nor only a question of excess fat in the lower limbs, nor a simple constitutional variation, as is sometimes reported, but it represents a pathology that requires appropriate treatment in order to avoid possible complications.
Complete decongestive therapy (CDT), characterized by manual lymphatic drainage, by the use of adequate elastic supports with gradual compression and / or valid functional bandages, by therapeutic exercises, and meticulous skin hygiene, is initially contraindicated in the cases in which obesity is present, as a co-morbid condition. Obesity is generally associated with important anatomical-functional changes affecting the cardiovascular, pulmonary, and musculoskeletal systems including, in particular, arterial hypertension, congestive heart failure, diabetes mellitus, hyperlipidemia, Pickwick's syndrome, and arthrosis of the hips, knees or feet. In these cases where there is therefore a combined form of lipedema and obesity, it is advisable to start complete decongestant therapy after carefully correcting the obesity-related disorders, not only with medical-conservative measures, by means of a suitable program of reduction of body weight, but also, and above all, of a surgical nature. The treatment of obesity is, in fact, indispensable for the successful decongestive therapy associated with microsurgical treatment to be successful.
Surgical treatment of obesity has undergone an epochal shift with the design and introduction of the biliopancreatic diversion (Biliopancreatic Diversion, BPD) by Prof. Nicola Scopinaro and his collaborators of the Surgical Clinic of the University of Genoa. Therefore, a fundamental qualitative change in the surgical therapy of obesity has been verified, since it guarantees a real resolution of the pathological condition by means of a functional regulation of energy intake and absorption, which results in a significant weight loss associated with a permanent normalization of glycemia and cholesterolemia in all cases.