Infectious outcomes of fibrin sheath disruption in tunneled dialysis catheters

Background and objectives: Fibrin sheath (FS) formation around tunneled central venous catheters (CVC) increases the risk of catheter-related bloodstream infections due to bacterial adherence to a biofilm. We sought to investigate whether FS disruption (FSD) at the time of CVC removal or exchange affects infectious outcomes in patients with CVC-related infections. Design, setting, participants, and measurements: Retrospective cohort study of 307 adult maintenance hemodialysis patients aged 18 years or older at a single center academic-based hemodialysis program (UHN, Toronto) who developed CVC-related infections requiring CVC removal or exchange between January 2000 and January 2019. Exposure was FSD at the time of CVC removal or exchange. Outcomes were infectious metastatic complications, recurrent infection with the same organism within 1 year, or death due to infection. We created a Markov Multi-State Model (MMSM) to assess patients’ trajectories through time as they transitioned between states. A time-to-event analysis was performed, adjusted for clinically relevant factors. Results: There was no significant relationship between FSD status at the time of CVC removal, the development of infectious complications in the multivariable model (adjusted HR = 0.71, 95% CI 0.09−5.80, p = 0.76), or mortality from infection (HR = 0.84, 95% CI 0.34−2.11, p = 0.73). Conclusions: FSD at the time of CVC removal was not associated with increased risk of infectious complications or death due to infection. Further prospective study is needed to determine whether FSD contributes to reducing CVC infectious related complications.

Transient bacteremia promotes catheter-related central venous thrombosis through neutrophil extracellular traps

Formation of intravenous catheter-related thrombosis leads to central venous stenosis in patients requiring renal replacement therapy or chemotherapy infusion, yet the triggering or mechanisms remain unclear, especially in patients without symptoms of infection. In this study, we found that neutrophil extracellular traps (NETs) could be detected in the fibrin sheaths from dialysis patients without clinical manifestations of infection. Confocal microscopy revealed bacteria imbedded in NETs in the fibrin sheaths. Thirty-nine of 50 (78%) fibrin sheath specimens contained bacteria detectable by 16S ribosomal RNA genome typing with a predominance of Staphylococcus aureus (69%). In rat models, transient bacteremia of S. aureus induced NETs in enlarged fibrin sheaths, and treatment with DNase I alone significantly reduced both NET and fibrin sheath formation surrounding the catheter. Therefore, transient bacteremia could be a silent trigger that induces NET-related immunothrombosis enhancing catheter-related central venous stenosis.

Entrapped peripherally inserted central catheter due to fibrin sheath in a neonate with noninvasive extraction and review of literature

Peripherally inserted central catheter line entrapment is a rare complication in the neonatal intensive care unit and only a small number of cases have been reported. While studies have suggested recommendations for removal, there is still a need for surgical intervention in some cases. This is a case of a premature infant with long term peripherally inserted central catheter line placement with fibrin sheath formation that required multiple attempts before successful noninvasive removal and a review of the cases with difficult peripherally inserted central catheter removal in newborns.

The Art of the Clinician

Background: The promotion of clinical abilities could represent a significant factor leading the clinicians to in making the correct diagnosis in a timely matter. Case: Our patient is a 42-year-old African male with a history of Hypertension, ESRD on hemodialysis via right-sided Permcath (PC), Mastoidectomy & Right ear surgery due to trauma in childhood, AV Fistula (Needed intervention 4 times) in left upper extremity, admitted due to witnessed seizures in the setting of hypertensive emergency. The patient denied family history and toxic habits. While the patient was at the emergency room, CT head revealed stable curvilinear hyper-attenuation thought to be a thrombosed developmental vein more likely than small subarachnoid hemorrhage. He was loaded with levetiracetam, received Ativan 1mg IV and HD done as per Nephrology. The patient was transferred to the floor he was not in acute distress and was asymptomatic, the cardiovascular (CV) examination showed regular pulse, normal S1, S2, S4+ appreciated with 2/4 diastolic murmur at second right intercostal space (ICS); 2/6 pansystolic murmur at third right intercostal space left parasternal border (LPSB) radiated to the right parasternal border (RPSB) and right mid-clavicular line (MCL); 3/6 systolic murmur at 5LICS MCL radiated to the posterior axillar line (PAL). Point of maximal impulse (PMI) displaced to mid axillar line (MAL). Parasternal heave present; the neurological exam was preserved. Endocarditis was suspected and echocardiogram was expedited, it showed severe aortic regurgitation, 1.60cm x 1.68cm mass in the tip of the catheter in the right atrium, possible vegetation in the tricuspid valve with mild regurgitation, moderate mitral valve regurgitation. Later, staphylococcus epidermidis was identified in blood cultures twice, as well as the culture from the PC. The transesophageal echocardiogram found 2.41 X 0.62 cm mass appears to be a fibrin sheath, possibly remnant of a prior catheter, small perforation in the non-coronary cusp likely in the setting of healed endocarditis. Infectious disease onboard for antibiotic management. Conclusion: The art of the clinician goes beyond the available technology; it could prevent the loss of critical time as well as unnecessary studies, guiding a better assessment and treatment of our patients and potentially improving their outcomes.

Central Venous Disease Increases the Risk of Microbial Colonization in Hemodialysis Catheters

Objectives: Tunneled-cuffed catheters (TCCs) are widely used in maintenance hemodialysis patients. However, microbial colonization in catheters increases the likelihood of developing various complications, such as catheter-related infection (CRI), catheter failure, hospitalization, and death. Identification of the risk factors related to microorganism colonization may help us reduce the incidence of these adverse events. Therefore, a retrospective analysis of patients who underwent TCC removal was conducted.Methods: From a pool of 389 adult patients, 145 were selected for inclusion in the study. None of the patients met the diagnostic criteria for CRI within 30 days before recruitment. The right internal jugular vein was the unique route evaluated. The catheter removal procedure was guided by digital subtraction angiography. Catheter tips were collected for culture. Biochemical and clinical parameters were collected at the time of catheter removal.Results: The average age of this cohort was 55.46 ± 17.25 years. A total of 45/145 (31.03%) patients were verified to have a positive catheter culture. The proportions of gram-positive bacteria, gram-negative bacteria, and fungi were 57.8, 28.9, and 13.3%, respectively. History of CRI [odds ratio (OR) = 2.44, 95% confidence interval (CI) 1.09 to 5.49], fibrin sheath (OR = 2.93, 95% CI 1.39–6.19), white blood cell (WBC) count ≥5.9 × 109/l (OR = 2.31, 95% CI 1.12–4.77), moderate (OR = 4.87, 95% CI 1.61–14.78) or severe central venous stenosis (CVS) (OR = 4.74, 95% CI 1.16–19.38), and central venous thrombosis (CVT) (OR = 3.41, 95% CI 1.51–7.69) were associated with a significantly increased incidence of microbial colonization in a univariate analysis. Central venous disease (CVD) elevated the risk of microbial colonization, with an OR of 3.37 (1.47–7.71, P = 0.004). A multivariate analysis showed that both CVS and CVT were strongly associated with catheter microbial colonization, with ORs of 3.06 (1.20–7.78, P = 0.019) and 4.13 (1.21–14.05, P = 0.023), respectively. As the extent of stenosis increased, the relative risk of catheter microbial colonization also increased. In patients with moderate and severe stenosis, a sustained and significant increase in OR from 5.13 to 5.77 was observed.Conclusions: An elevated WBC count and CVD can put hemodialysis patients with TCCs at a higher risk of microbial colonization, even if these patients do not have the relevant symptoms of infection. Avoiding indwelling catheters is still the primary method for preventing CRI.

Calcified Catheter-Related Fibrin Sheath Forms Large Intravenous Cast In Hemodialysis Patient Causing Embolic Sequalae: A Case Report

Background: Catheter related sheath (CRS) formation secondary to chronic indwelling central venous catheters (CVC) is a well-documented complication. When these fibrin sheaths calcify, they can form a “cast” surrounding the catheter. Upon removal of the CVC a rare complication can occur where the calcified sheath remains in-situ leaving behind an intraluminal catheter-shaped cast. Case Presentation: We present the case of a 57-year-old dialysis dependent woman found to have a right internal jugular vein cast during the evaluation and treatment of methicillin resistant staphylococcus aureus (MRSA) bacteremia. Conclusions: This case reviews and discusses the embolic complications suspected to be a result of this cast. Our case provides insight into the clinical course, diagnostic methods, and imaging identification of a rare pathology and its unique complications.

Fibrin sheath disruption during guidewire exchange for bacteremia: Low recurrence of infection and preservation of vascular access sites

Background: Catheter-associated bacteremia (CAB) often leads to removal of tunneled dialysis catheters with delayed insertion (RDI). Exchange over a guidewire (ExW) can be considered for access site preservation. Fibrin sheath disruption (FSD) during exchange is not standard practice for infected catheters. Here we present the first analysis of outcomes after such exchanges (ExW-FSD). Methods: Retrospective analysis of catheter exchanges and removals performed by interventional nephrology for bacteremia in 2008–2011 observed for 20.5 months. Charts were reviewed for recurrent or new bacteremia and death at 3 months, and for occurrence of thrombosis or stenosis along the catheter site. Catheter exchange with central venogram and fibrin sheath disruption was our standard of care in all patients presenting for CAB. RDI was performed either for tunnel infection, non-clearing of infection or at the request of referring physicians. Results: Over 4 years, 66 patients were treated for CAB. Forty-two patients underwent ExW-FSD, which was performed even for Staph. aureus, gram negative bacteremia or candidemia. RDI was performed in 24 cases. Bacteremia recurred in 3 (7%) patients after ExW-FSD, and in 7 (30%) cases after RDI ( p = 0.02). There was no significant difference in new infections: 5 (12%) after ExW-FSD and 2 (8%) after RDI. There was no death within 3 months after ExW-FSD and 4 (27%) ( p = 0.005) deaths in the RDI group. There was one new central venous stenosis in the ExW-FSD group (2%) with no loss of access site, and 8 (33%) patients developed thrombosis/stenosis along the prior catheter track after RDI (33%) ( p = 0.006) with loss of access site in (21%). Conclusions: In this retrospective analysis of treatment of CAB, ExW-FSD was associated with lower recurrence of bacteremia, lower death rate and a lower incidence of access site loss compared to RDI. These data support ExW-FSD use in patients with CAB.