Peritonitis is defined as inflammation of the peritoneum. The inflammatory response involves vasodilation, exudation of protein-rich fluid, cellular infiltration, pain and, chronically, formation of fibrous adhesion. The disease can be classified into primary and secondary cases.
It begins in the venous plexus along the medial side of the foot, and it runs up the medial side of the leg and knee, alongside the saphenous nerve. In the thigh, the long saphenous vein continues up the medial surface, accompanying the medial femoral cutaneous nerve.
Tributaries. 1  hemiazygos vein is a similar structure on the opposite side of the vertebral column and drains into the azygos vein. 2  posterior right intercostal veins. 3  right superior phrenic vein. 4  right superior intercostal vein. 5  tracheal veins. 6  oesophageal veins. 7  bronchial veins. 8  pericardial veins.