Result of lymphangitis, of heart disease, of pulmonary arterial
thrombosis, of external jugular plugging. Causes, obstruction to lymph
flow, compression, increased venous blood pressure, fibrinous lymph
coagula, action of sensory nerves, of lymphadenitis, anæmia. Symptoms
like dropsy if in plexus, in large lymphatics, moniliform swelling,
sacculation, wounds discharge lymph, hyperplasia of connective tissue,
fatty deposits, lipomata. Treatment, elastic bandage, cold,
astringents, iodine, punctures, ligatures, cauterizations, tonics.
The most striking cases of dilatation of the lymphatics in the lower
animals are met with in horses that have suffered repeatedly and
severely from the lymphangitis of plethora. Then the lower part of the
shank and the pastern are enormously thickened to perhaps two or even
three feet in circumference, and skin and connective tissue are the seat
of a general dilatation of the lymphatic plexus and vessels with great
thickening of their walls. Nocard and Barrier record cases of general
dilatation of the lymphatics in dogs in connection with heart disease,
also the case of a horse with old standing thrombosis of the pulmonary
arteries, hypertrophy of the right heart, and dilatation of the thoracic
duct to the size of the arm and of the lymphatics of the mesocolon to
the diameter of half an inch to nearly an inch. Nocard records two cases
in the horse, one of a reticular lymphangioma of the sheath, and the
other of dilatation of the lymph vessels accompanying the saphena vein
on the inside of the thigh. This formed small, soft, fluctuating,
extremely irregular tumors, completely covering the vein for a space of
about four inches.
In both cases the dilatations were surrounded by a thick layer of
connective tissue filled with liquid. Virchow records a case of a
new-born calf in which a thrombosis of the external jugular vein caused
obstruction of the mouth of the thoracic duct, and a consequent extreme
distension of all the splanchnic lymph vessels with a slightly
sanguinolent fluid. The intestines especially were covered everywhere
with broad, bead-like canals, arranged so closely together that the
intervening tissue could be scarcely recognized.
The _causes_ of lymphangiectasis appear to be generally some obstruction
to the onward flow of the lymph. Any diseased condition, therefore, that
causes compression of the larger lymph vessels may cause dilatation of
the smaller ones leading into these. General distension may come from
disease of the lungs or left heart and increased venous blood pressure,
or from thrombus of the jugular, or a tumor obstructing the thoracic
duct, while local engorgements may come from the pressure of tumors, or
the occurrence of lymphangitis and formation of fibrinous coagula. In
cases of partial obstruction of the lymph vessels the increased
secretion of lymph may lead to distension and enlargement. It may be
named in this connection that irritation of the sensory nerves in dogs
has been shown to determine a larger production of lymph (Krause).
Lymphadenitis and the obstruction of the passage of lymph through the
glands is an obvious cause, and hence the disease is specially liable to
appear in connection with diseases which show a predilection for the
lymphatics (tuberculosis, glanders, strangles, carcinoma, etc.)
In his work on dilatation and occlusion of lymph channels Busey shows
that in man the majority of cases are in hospital patients in whom blood
and general health have been impoverished and reduced by unhygienic
conditions. One case gave support to the theory of maternal impression,
the pregnant mother having suffered from over-use of the right limb on a
sewing machine, and the offspring having shown extensive
lymphangiectasis in the right leg.
_Symptoms_ consist in enlargement of the lymph vessels or plexus, and
often of the glands. If of the lymph plexus it may appear like a
dropsical effusion in the part, with or without saccular dilatations at
intervals. If of the larger vessels, their tortuous anastomosing trunks
following largely the lines of the veins are usually characteristic. If
the distension is slight it is usually moniliform, as the valves are
still intact, and the intervals between them stand out as bladder-like
masses. If the structure is wounded or if it ulcerates there is the
discharge of a straw-colored fluid, often rendered milky by the presence
of fatty granules, and at times tinged with blood. There is always a
tendency to the increase and condensation of the connective tissue
surrounding the vessels, and fatty degeneration and the formation of
lipomata are not uncommon.
_Treatment._ Compression, by flannel or elastic bandage, from the foot
upward, is the simplest and most promising treatment when the limb is
affected. The local application of cold, astringents or iodine may be
added. Punctures, ligatures, and cauterization have not given
encouraging results. Ligature of the nutrient artery of the part, has
succeeded in one or two cases, but has failed in others. Tonics are to
be tried more particularly in cases due to specific debilitating
diseases. Sometimes a spontaneous recovery has been noticed when the
surrounding connective tissue has increased and contracted in connection
with inflammation.