The restenosis phenomena can be explained by the physiological response to the trauma caused by the balloon when inflated to compress the atheroma. Many factors can influence the process e.g. patient , procedure and vessel condition before intervention.it can be considered as hypertrophic wound healing from the interaction between monocyte-derived macrophages , T cells and arterial wall .the inflammatory response lead to Neointimal Hyperplasia the terminology uses to describe the proliferation and migration of vascular smooth muscle cells . Elevated inflammatory and coagulation factors markers levels after angioplasty has been suggested as predictors for the possibility of restenosis . The inflammatory theory was more supported when using immunosuppressive drugs like Sirolimus shows positive effects on reducing restenosis rate.