545


Thrombosis  of  the  vena  cava  apceniiens  or  of  both  common  iliac  veins
results  in  the  development  upon  the  surface  of  the  abdomen  and  antero-
lateral aspects  of  the  chest  of  prominent  sinuous  venous  enlargements,
sometimes  reaching  the  thickness  of  a  finger,  by  which  the  blood  from  the
lower  extremities  and  the  kidneys  is  conveyed  to  the  veins  of  the  thorax.
In  cirrhosis  of  the  liver  and  portal  thrombosis  the  compensatory  circula-
tion is  often  by  way  of  the  superficial  veins.  Occasionally  a  greatly  enlarged
para- umbilical  vein  passes  from  the  hiluc  of  the  liver  along  the  course
of  the  round  ligament  and  joins  the
epigastric  veins  at  the  navel,  produc-
ing a  large  varix  with  wavy  radial
distribution  of  the  veins  known  ;is
the  caput  Medusm.  More  commonly
branches  pass  in  the  round  and  sus-
pensory ligaments  and  unite  with  the
epigastric  and  mammary  systems.
