Quantification of Fibrin in Blood Thrombi Formed in Hemodialysis Central Venous Catheters: A Pilot Study on 43 CVCs

Abstract

The analytical method presented here proved to be a rapid and effective way for quantifying fibrin content in thrombi formed on CVCs with potential application in future clinical studies.

Microstructural evaluation by confocal and electron microscopy in thrombi developed in central venous catheters

“…These results were also found by a study evaluating the thrombus present in central venous catheters by Two-photon laser scanning microscopy (2) . This type of microscopy reaches a greater tissue depth when compared to Confocal Laser Scanning Microscopy, and the greater the tissue depth evaluated, the greater the red blood cell and white blood cell concentration, and the smaller the amount of fibrin interconnected to the cells (2) . In another study, a venous thrombus was observed by Two Photon Laser Scanning Microscopy in which the fibrin plate was surrounded by white blood cells close to the inner wall of the catheter opening (3) .…”

“…Initial forming and maturing of the different thrombotic tissue components may lead to occlusion of the CVC lateral openings, mainly due to different conformations of the fibrin inside the opening and its adsorption to polymeric materials. Fibrin deposition on the catheter causes the surface to encapsulate, forming a sheath at the distal tip of the catheter (4)(5) .The process of protein adsorption to the polymer may become irreversible, and tissue dissolution becomes ineffective even by introducing fibrinolytic agents due to strong covalent bonds between plasma proteins and the catheter wall (2)(3) . The activation of a coagulation cascade increases the tendency for thrombus formation, which is an important cause of complications in patients using a venous catheter, which can not only lead to thrombosis near the vascular access, but also to emboli formation, deep venous thrombosis and the possible development of cardiac ischemia (8)(9)(10)(11)(12)(13)(14) .…”

“…Considering the three-dimensional microscopic architecture of a thrombus, Scanning Electron Microscopy (SEM) is one of the elective techniques for morphological characterization (13) . However, despite having high potential, SEM only provides information on superficial thrombus layers and their structural analysis (2)(3) . Integrating SEM and Confocal Laser Scanning Microscopy are promising for investigating thrombi in human samples, thus enabling better care performance in clinical practice and in the maintenance of CVCs, as they are evidence-based practices that respond to issues that arise daily.…”

“…Central venous catheters (CVCs) are radiopaque, and made of silicone, polyurethane or teflon. They may have one to three lumens arranged in parallel at the proximal end, and generally have lateral orifices at their distal end (1)(2)(3) . The openings may induce fibrin formation and subsequent thrombus development.…”

“…The openings may induce fibrin formation and subsequent thrombus development. Fibrin sheaths are composed of fibrinogen, albumin, lipoproteins, and coagulation factors that begin within 24 hours after catheter insertion (1)(2)(3)(4) . Fibrin is the first structural protein to form in thrombus composition and it may lead to catheter occlusion, extravasation of infused fluid, exchanging the catheter and loss of secondary access to thrombosis (5) .…”