Clinical Pathophysiology
nThe
nidus for a clot is often an intimal defect
nWhen
a clot forms on an intimal defect, the coagulation cascade promotes clot
growth proximally. Thrombus can extend from the superficial veins into the
deep system from which it can embolize to the lungs.
nOpposing
the coagulation cascade is the endogenous fibrinolytic system. After the
clot organizes or dissolves, most veins will recanalize in several weeks.
Residual clots retract as fibroblasts and capillary development lead to
intimal thickening.
n
Venous hypertension and residual clot may destroy valves, leading to the
postphlebitic syndrome, which develops within 5-10 years
nEdema,
sclerosis, and ulceration characterize this syndrome, which develops in
40-80% of patients with DVT.
n
patients also can suffer exacerbations of swelling and pain, probably as a
result of venous dilatation and hypertension
n Pulmonary
embolism (PE) is a serious complication of DVT. Many episodes of pulmonary
embolism go unrecognized, and at least 40% of patients with DVT have
clinically silent PE on VQ scanning
.
Presentation
and Physical Examination
|