Insufficient development during embryo-fetal life of anatomic structures in charge of lymphatic drainage, which, therefore, are hypoplastic and often insufficient to cope with normal lymphatic drainage. There are different degrees of lymphatic hypoplasia: in the most severe cases, lymphatic insufficiency becomes clinically overt after a few days from birth, whereas in patients with moderate deficit, it may become clinically overt even after many years, or develop concurrently with traumatic or surgical lesions that damage the lymphatic structures.
Pathological macro and microscopic alterations involving lymph node structures and lymphatic collectors, in lymphoperipheral edema due to lymphatic hypoplasia (and hypo-dysplasia).
Lymphatic load means the amount of fluid and various other substances that must be drained by lymphatic circulation in a set period of time.
Surgical therapy and, in particular, derivative and reconstructive microsurgery have recently been included in the combined, multimodal, and integrated treatment of both primary and secondary lymphedema, thus becoming standard professional know-how of physicians treating lymphatic system disorders. Microsurgical techniques adopted for “conservative and functional” lymphedema surgery are classified into derivative and reconstructive. Derivative techniques are by far the most common ones. They aim at resuming lymph flow by fashioning a lymph-venous drainage, using lymph nodes or, better, lymphatics directly that are being anastomized to the main satellite vein:
- Lymph node-Venous Anastomosis (LNVA);
- Lymphatic -Capsular-Venous Anastomosis (LCVA – Campisi, 1978);
- End-to-end Lymphatic -Venous Anastomosis (EE-LVA);
- End-to-side- Lymphatic -Venous Anastomosis (ES-LVA).
With reconstructive microsurgical techniques, lymph flow circulation is reinstated by by-passing the site of the block through the insert of autologous, either lymphatic or venous, segments, to join collectors upstream and downstream the obstacle:
- Lymphatic -Lymphatic Anastomosis (LLA);
- Segmental Lymphatic Vessel Autotransplantation (SLAT);
- Lymphatic-Venous-Lymphatic-Plasty or Lymphatic-Venous-Lymphatic Anastomosis (LVLA – Campisi, 1982);
- Free Lymphatic -Lymph Nodal Flaps (FLF).
The techniques that so far have proved to be more effective and that are most commonly applied in patients with chronic, primary or secondary, lymphedema of the extremities are LVA and LVLA, in patients with severe concurrent venous insufficiency.
Lymphatic -Capsular-Venous Anastomosis (LCVA).
Statistical assessment of microsurgery outcome depending on lymphedema stage (15 year follow-up).
Short and thin lymphatic vessels connecting the absorbing peripheral section with the main lymphatic drainage pathways proper, namely, lymphatic and main lymphatic ducts.
Lymphatic valves are identical to venous valves, but they are many more in number. The peculiar rosary-shape of lymphatic vessels is due to the arrangement of these valves, which consist of endothelial cell laminas in seamless connection with the intima of the lymphatic vessel. They lack smooth muscle cells. Just like in the nervous system, lymphatic valves are arranged to follow the flow direction and are located to allow a quick flow of the lymph through the larger lymphatics, while preventing its back-flow.
In vivo staining of lymphatic vessels (see: Lymphochromic Test, Lymphography).
Lymphedema is an edema caused by either mechanical or dynamic insufficiency in lymph circulation. Low output lymphedema (mechanical insufficiency) may be caused by congenital lymphatic dysplasia (primary lymphedema), or it may be due to secondary anatomic impairment of lymphatic structures, for example following surgeries or repeated lymphangites, with subsequent diffuse lymphangiosclerosis and functional insufficiency (secondary lymphedema). Conversely, high output lymphedema (dynamic insufficiency) is due to higher lymph production, associated with arteriovenous insufficiency of capillary microcirculation: with this condition, despite regular transport capacity of the lymphatic pathways, lymph stasis is brought about by an abnormal increase in lymphatic load (see), thus leading to edema, which, in turn, may become chronic, if the underlying conditions are maintained over time, for example in case of liver cirrhosis, chronic venous insufficiency of the lower limbs with peripheral edema, and nephrosic syndrome with anasarca. Lymphedema therapy is based on three fundamental principles: physical treatment (manual and mechanical lymphatic drainage, and multilayer functional bandages), pharmacologic treatment (diuretics, benzopyrones, antibiotics, and diet), and surgical treatment, with particular reference to derivative and reconstructive microsurgery. The synergistic application of the above specified treatments has led to treatment outcomes that would have not been achieved if individually applied. This also explains why certain therapeutical methods, even when correctly applied, have failed, since they have not fully benefited from the potentials offered by the so called “combined” medical-physical-surgical therapy, which is by now internationally recognized as the “gold standard” in lymphedema treatment.
Examples of primary or congenital lymphedema.
Examples of lymphedema of the external genitalia, with cutaneous chylous-lymphostatic verrucosis due to chylous-lymphatic gravitational reflux.
Lymphedema of the left eyelid, in a rare case of Thomsen’s disease (myotonia congenita) (see).
Examples of severe, very advanced stage lymphedema, of the lower extremities, mono-and bilateral (in the latter case, it is also associated with lymphedema of the external genitalia and chylous ascites).
Secondary lymphedema: upper and lower extremities.
Lymphedema may occur as a primary condition (primary lymphedema) or secondary to a previous pathological condition (secondary lymphedema). Secondary lymphedemas often have a latent congenital component, which becomes clinically overt only after some triggering event. Lymphangiodysplasia with varying severity is the etiological origin of primary lymphedemas, which are distinguished into neonatal or congenital proper (Milroy disease), with early (Meige syndrome) or late onset. Secondary lymphedemas more commonly have a surgical origin, such as for example in the case of lymphadenectomies for oncological control (post-mastectomy lymphedema), but may also be the result of trauma, infection (filaria related or post-lymphangitis lymphedemas), or they may be linked to a loss of neuro-muscular functions (functional or “disuse” Lymphedema).
Lymphedema secondary to trauma with relevant lymphoscintigraphy, which, if superimposed, shows that the tracer is blocked at the level of the scar, with corresponding lymph stagnation in the medial portion of the thigh.
Lymph collection in a newly developed cavity. Depending on its anatomic localization and the presence of any associated lesions, some varying chylous component (lymph-chylocele) may also be observed. It is a common complication after lymphadenectomy, but it may also develop as a primary manifestation. Symptoms of lymphocele depend on its size and on whether it presses against surrounding tissues and structures. Lymphocele is treated by surgery with its radical resection associated with concurrent laser “sealing” of any lymphatic vessels, which could give origin to lymphorrhoea or even a recurrency.
Inguinal lymphocele secondary to inguinal lymphadenectomy.
Left inguinal lymphocele studies with MR scan (posterior view).
International scientific journal on lymphology, and the official journal of the International Society of Lymphology.