Dynamic Study On Hislopathology Of Fibrin Sheath Formed Around Hemodialysis Central Venous Catheters

Background：Fibrin sheath is considered as the most common complication resulting incatheter dysfunction,seriously affects the quality of life and life span in hemodialysispatients.There are several autopsies and animal researches home and abroad,but weare still lake of consensus of the histopathology，dynamic formation characteristics offibrin sheath.Objective：to make clear the histopathology and evolution characteristics of fibrin sheath,inorder to investigate methods of slowing or restraining progress.Methods：10experimental swines are divided into5groups(7days group,14days group,1month group,2months group,3months group),each group contains2swines.Externalvenous catheterization are done to each swine,get the specimen after7days,14days,1month,2months,3months separately,observe growing states of each fibrinsheath,perform HE stain,VG stain,SMA and CD31inmunohistochemistry of each partof the specimen(tip part,middle part,entrance part),study it’s histopathology andevolution characteristics, investigate it’s formation mechanismResults：fibrin sheath are found in all the swines.sheath in all parts of7days group,14days group and entrance part of1month group mainly contains thrombus,fibrinoidnecrosis,calciun salt precipitation,with/without Inflammatory cell infiltration;sheathorganized in entrance part of1month group，all parts of2months group and3months group,contains numerous collagen fibers,smooth muscle cells,coatingendothelial cells,which is mature fibrin sheath.Conclusion：1The formation mechanism of fibrin sheath is the blood incompatibilities ofvenous catheter firstly,and blood cells and protein accumulate on the rough outsidesurface of the catheter. 2Fibrin sheath forms at all parts of the catheter surface at the same time,butorganization starts at the entrance part and develops gradually towards catheter tip.3Fibrin sheath performs as thrombus and fibrinoid necrosis initially,thendevelops into fully organized fibrinous connective tissue which contains collagenousfiber, smooth muscle cell,and coating endothelial cells.