title: Fibrin sheath formation and intimal thickening after catheter placement in dog model: role of hemodynamic wall shear stress.
abstract: OBJECTIVE
  To investigate the role of wall shear stress in aspects of the formation of fibrin sheath and intimal thickening in a dog model.
  
  
  METHODS
  Tunneled silicone 14.5-F catheters were inserted into the left internal jugular vein in eight dogs. The dogs were separated into two groups according to catheter indwelling time of 14 and 28 days. All dogs underwent extracorporeal circulation three times a week. Multidetector computed tomography venography (MDCTV) examination was used to examine the catheter tip thrombus. After the animals were sacrificed, histological and immunohistochemistry evaluations were performed to confirm specific cell populations. We used computer modeling to generate wall shear stress profiles for the blood flow through the catheter.
  
  
  RESULTS
  Catheter-related sheaths were identified in all catheter specimens, but there was no fibrin sheath around the catheter tip. There were also differences in wall shear stress between the different venous wall sites. Differences in vein wall thickening at different sites have been found at both 14 days (intima to media (I/M) ratio S1 vs S2: p = 0.01, S3 vs S4: p&lt;0.01) and 28 days (I/M ratio S1 vs S2: p&lt;0.01, S3 vs S4: p&lt;0.05).
  
  
  CONCLUSIONS
  After catheter placement, fibrin sheath formation partially covered the catheter. Meanwhile, focal areas of intimal thickening were also seen in the venous wall adjacent to the sites of high wall shear stress. These findings indicate an important role of wall shear stress profiles in fibrin sheath formation and intimal thickening.
authors: Department of Kidney Disease and Blood Purification, Institute of Urology and Key Laboratory of Tianjin, 2nd Hospital of Tianjin Medical University, Tianjin - PR China.
authors: Li Hua
authors: LH
authors: Wang
authors: Fang
authors: F
authors: Wei
authors: Lan
authors: L
authors: Jia
authors: Zhi
authors: Z
authors: Lu
authors: Bo
authors: B
authors: Wang
authors: Hong Ye
authors: HY
authors: Dong
authors: Hai Bo
authors: HB
authors: Yu
authors: Gui Jiang
authors: GJ
authors: Sun
authors: Jie
authors: J
authors: Yang
authors: Bo
authors: B
authors: Li
authors: Jia
authors: J
authors: Meng
authors: Rui Ning
authors: RN
authors: Zhang
authors: Xue Qing
authors: XQ
authors: Bi
authors: Hai Yan
authors: HY
authors: Chen
authors: Ai Li
authors: AL
authors: Jiang
mesh_terms: D000818:Animals; D061807:Catheter Obstruction / Q000209:etiology*; D002405:Catheterization, Central Venous / Q000009:adverse effects* / Q000295:instrumentation; D062905:Central Venous Catheters / Q000009:adverse effects*; D003198:Computer Simulation; D004285:Dogs; D004867:Equipment Design; D005337:Fibrin / Q000378:metabolism*; D006439:Hemodynamics; D007601:Jugular Veins / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D023421:Models, Animal; D008955:Models, Cardiovascular; D061330:Multidetector Computed Tomography; D058426:Neointima; D010690:Phlebography / Q000379:methods; D012828:Silicones; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D012828:Silicones; D005337:Fibrin