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.
The femoral vein is considered a deep vein, unlike the adjective superficial suggests and has led some physicians to falsely conclude it is a superficial vein, which has resulted in patients (with deep vein thrombosis) being denied efficacious anticoagulant or thrombolytic therapy.