Page 700 - My FlipBook

710 GENERA L PA THOL G Y.

will now admit of answer, thanks to the experimental study of recent
years.
AVhen a blood-clot has formed from any cause in the midst of tissues
of fair functional activity, a^\•ay from contact with the air, and there-
fore safe from contamination from without, it causes a slight inflamma-
tory process to be developed in its immediate neighborhood. This
brings to the spot numbers of the amoeboid cells, which actively attack
the clot in all its parts, but especially its margins. In addition to the
cells that wander free into the clot, granulations spring out into it from
all sides, and as they grow the clot disappears to give them room (Figs.
399 and 400). The clot is digested, dissolved, and removed. Thus the
connective-tissue forming cells grow into the substance of the clot as they
grow into the meshes of the sponge in the sponge graft, and the clot is
removed by solution in the same manner as the sponge. In this manner
very large clots are many times removed, leaving in their stead a quan-
tity of newly-formed tissue that is of no value. In time this also shrinks
aM'ay partly and is partly absorbed, so that in the end but little remains
to show that there has been a clot in the lo(;ality. The clot itself has no
power of organization any more than the sponge in the sponge graft,
but as the sponge it acts as a stimulant to the growth of the granula-
tions by which it is removed. It is possible also that in some positions
the blood-clot may, as the sponge graft, act as a ladder on tchich granu-
lations may climb, and in this manner assist in the formation of tissue
for the filling out of lost parts ; but in this respect it is much inferior
even to the sponge in the character of the new tissue produced, which
is usually of a very loose texture and shrinks together to an extreme
degree (Fig. 401).
Fig. 401.

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From the Cross-section of an Arterial Thrombus of Three iSIonths: /, luraina of vessels in the throm-
bus, X, X, X (X 300, Riudfleisch).
In order that the granulations shall grow in blood-clot it must remain
a.septic. Therefore it usually hapjiens that clots which are exposed to
the air are decompo.sed, and constitute a much greater hindrance to the
healing ]iroccss than in subcutaneous wounds. It has been shown by
Ijister that blood-clots do not decompose as readily as mo.st other sub-
stances yet clinical ex]x'ricnco demonstrates that in very many cases
;
their decomposition seriously interferes with the process of granulation
by becoming the foci of septic ])rocesses. If the clot remains aseptic,
it retards the jirocess of healing by the time required to fill it with
granulations. I think a close comparative study will show that granu-