Fibrin sheath and its relation to subsequent events after tunneled dialysis catheter exchange

Ultrasonic characteristics of inserted central catheter related fibroblastic sleeve

This study was aimed to summarize the ultrasonic characteristics of inserted central catheter (ICC) related fibroblastic sleeve, providing theoretical basis for its early diagnosis. Clinical and ultrasonic data of patients with ICC confirmed by pathology to have fibroblastic sleeves in our hospital from June 4, 2020 to April 1, 2024 were collected. All ICCs were made of polyurethane. Patients required the ultrasound evaluation due to local swelling and pain, abnormal coagulation function, lack of response to flushing of saline and heparin, or before extubation. The ultrasonic characteristics of fibroblastic sleeve such as its starting point, shape, thickness, internal echo, number of layers, relationship to the catheter, and presence or absence of thrombosis were analyzed. After the removal of the ICC, there was a membrane-like structure adhesion on the surface of the catheter, which was composed of endothelial cells, smooth muscle cells, collagen and fibrous connective tissues. A total of 95 patients with pathologically confirmed fibroblastic sleeve were present, of which 44 patients had only fibroblastic sleeves (46.32%) and 51 patients had fibroblastic sleeves with thrombi (53.68%). The fibroblastic sleeve originated from the site where the catheter contacted the vein wall and extended in a distal direction, with a thickness ranged between 0.7  and 5.6 mm. With the pathological results as the gold standard, the optimal cut-off value for the diagnosis of fibroblastic sleeve with thrombosis was 2.58 mm, and the sensitivity and specificity of the diagnosis were 95.45% and 96.08%. Compared to echogenicity of the catheter wall, hyperechoic or isoechoic fibroblastic sleeves were observed in 89 patients, while hypoechoic fibroblastic sleeves were observed in 6 patients. There were significant differences in the location of catheterization and duration of catheterization between the single-layer group and the double-layer group (P < 0.05). Fibroblastic sleeves were tightly attached to the catheter walls in 78 patients and loosely attached to the catheter walls in 17 patients, with significant differences in the location of catheterization and duration of catheterization (P < 0.05). ICC-related fibroblastic sleeves have specific ultrasonic characteristics. Understanding these ultrasonic characteristics can provide a reliable basis for their early diagnosis and timely treatment.

A novel extra-catheter guide wire technique for in situ exchange of dysfunctional tunnelled central venous hemodialysis catheter

BACKGROUND

Tunneled central venous catheters (tCVC) exchange may be difficult in some situations. We retrospectively report our preliminary experience of a novel extra-catheter guide wire technique for exchange of dysfunctional tCVC.

MATERIALS AND METHODS

Retrospectively analyze the demographics, treatment details and outcomes data of 39 patients received tCVC exchange from January 2018 to January 2019. According to whether guide wire could pass through the catheter lumen, patients were divided into in-catheter group and extra-catheter group. The technical successful rate, peri-operative complications, 1-month and 6-month catheter flow rate was recorded and compared between the 2 groups.

RESULTS

The final study population consists of 39 patients, including 16 in-catheter group and 23 extra-catheter group. The technical successful rate was 100% in both groups. All patients achieved restoration of line patency and completed at least 1 hemodialysis section. The 1-month (267.69 ± 20.12 vs. 274.13 ± 17.69, p = 0.604) and 6-month (255.81 ± 12.93 vs. 256.97 ± 11.20, p = 0.403) catheter flow rate was comparable between the 2 groups.

CONCLUSION

The novel extra-catheter guide wire technique was helpful for in situ exchange of dysfunctional tunneled central venous hemodialysis catheters, especially when the guide wire could not pass through the catheter lumen.

[Catheter Replacement Methods in Hemodialysis Patients With Dysfunctional Tunneled-Cuffed Catheters With Fibrin Sheaths]

Objective

Tunneled-cuffed catheters (TCCs) are frequently used for establishing hemodialysis access for maintenance hemodialysis in older patients with exhausted resources of peripheral vessels. Fibrin sheath formation around the catheter is one of the most common complications of long-term use of indwelling catheter, which may cause the malfunction of the catheter. In this study, we intend to compare the prognosis of two catheter replacement methods, in situ replacement and replacement through a fibrin sheath crevice, with both being assisted by balloon dilation, and to explore the optimal catheter replacement process.

Methods

A retrospective study was conducted with 52 patients who underwent a replacement of their TCCs. Among them, 27 cases had their TCC replaced by the modified method of replacement through a fibrin sheath crevice and were referred to as the sheath crevice group, while 25 cases underwent in situ catheter replacement and were referred to as the in situ group. The primary outcome indicators included maximum blood flow in hemodialysis catheter and the urea clearance rate calculated by Kt/V values at the 1, 3, and 6-month follow-ups. The secondary outcomes included dialyzer alarms being set off and catheter-related infections during follow-up.

Results

There was no significant difference between the general data of the two groups. There was no massive blood loss during the replacement procedure. Neither were there cardiac tamponade, catheter-associated infections, or other complications. Follow-ups were made 1, 3, and 6 months after the replacement procedure. The sheath crevice group had higher catheter blood flow and Kt/V values at the 6-month follow-up than the in situ group did ([241.85±9.62] mL/min vs. [234.40±11.21] mL/min, P=0.014 and 1.31±0.55 vs. 1.27±0.49, P=0.005, respectively). During the follow-up process, access alarms were reported in 5 patients (three in the in situ group and two in the sheath crevice group) during dialysis. No catheter-associated infection occurred in either group.

Conclusion

The catheter replacement method of balloon dilation-assisted catheter insertion through a fibrin sheath crevice is safe and effective, resulting in better long-term catheter blood flow compared with that of in situ catheter replacement.

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.

Endovascular Endocarditis Within the Superior Vena Cava of a Patient With a Tunneled Catheter for Hemodialysis

Tunneled hemodialysis catheters, such as permacaths, are frequently used for vascular access in end-stage renal disease (ESRD) patients. The use of these catheters is associated with bloodstream infections, thromboses, and infective endocarditis. While valvular endocarditis is a more common entity, non-valvular endovascular endocarditis is less commonly reported in the literature. Fibrin sheaths which form along the catheter may act as niduses for infection, which can then seed the surrounding tissues. We present a case of infective endovascular endocarditis originating from an infected fibrin sheath in the superior vena cava of an ESRD patient. 

CT and Sonographic Findings of a Calcified Fibrin Sheath From an Umbilical Venous Catheter in a Neonate

Central venous catheters are ubiquitous in current medical practice in intensive care units and for long-term nutrition, chemotherapy, and antibiotic therapies. Umbilical venous catheters provide short-term central vascular access and are used in the neonatal period. This case presents sonographic and CT imaging findings of an intrahepatic and intracardiac calcified fibrin sheath following removal of a short-term umbilical venous catheter in a 32-day-old premature neonate.

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.

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.

The fibroblastic sleeve, the neglected complication of venous access devices: A narrative review

The presence of a vascular access device (or of any intravascular foreign body) inside the bloodstream is often associated with the formation of a connective tissue sleeve around the catheter (often named-erroneously-"fibrin sleeve"). Such sleeve is usually a physiological phenomenon with little or no clinical relevance, but its pathogenesis is still unclear, so that it is frequently confused with venous thrombosis; also, its relationship with other major catheter-related complications, such as venous thrombosis and bloodstream infection, is uncertain. This narrative review tries to convey in a systematic form the current knowledge about pathogenesis, incidence, clinical manifestations, diagnosis, and management of this phenomenon.

Rare Case of a Calcified Catheter-Related Sheath Embolizing to the Right Pulmonary Artery

Catheter-related sheaths, formerly known as "fibrin sheaths," are the most common complications of central venous catheters. Although usually harmless, they can very rarely detach from the venous wall against which they were formed and embolize with effects ranging from subclinical embolisms to death. This rare occurrence has only been described a few times in the literature to date, and to our knowledge, the embolized sheath has never been directly visualized with CT. We report the case of catheter-related sheath embolization to the right pulmonary artery in a child, as confirmed on CT.

Clinical and Regulatory Considerations for Central Venous Catheters for Hemodialysis

Central venous catheters remain a vital option for access for patients receiving maintenance hemodialysis. There are many important and evolving clinical and regulatory considerations for all stakeholders for these devices. Innovation and transparent and comprehensive regulatory review of these devices is essential to stimulate innovation to help promote better outcomes for patients receiving maintenance hemodialysis. A workgroup that included representatives from academia, industry, and the US Food and Drug Administration was convened to identify the major design considerations and clinical and regulatory challenges of central venous catheters for hemodialysis. Our intent is to foster improved understanding of these devices and provide the foundation for strategies to foster innovation of these devices.

Nonthrombotic Pulmonary Embolism From Inorganic Particulate Matter and Foreign Bodies

Nonthrombotic pulmonary embolism (NTPE) is a complete or partial occlusion of the pulmonary vasculature by various organic and inorganic materials. These materials include organic particulate matter (PM) such as adipocytes, tumor cells, bacteria, fungi, or gas and inorganic PM. Although NTPE due to organic PM has been extensively reported in the medical literature, there are no comprehensive reviews of inorganic material embolizing to the lungs. The purpose of this article is to examine the current literature describing NTPE resulting from inorganic PM and foreign bodies. Cases of NTPE are uncommon and often difficult to diagnose. The diagnosis is challenging due to its varied presentation, clinical features, and unusual radiologic features. In contrast to the "classic" pulmonary thromboembolism, the pathophysiologic effects of embolism by PM are not only mechanical but also a consequence of the nature of the offending material. NTPE caused by these substances can be relatively innocuous, life-threatening, or lead to chronic pulmonary disease, if left undetected. We hope that the heightened sense of awareness of this entity may allow earlier diagnosis and recognition of its complications.

Thrombotic complications and tip position of transjugular chronic dialysis catheter scheduled into superior vena cava: Findings on HR-MRCP and HR-T2WI

BACKGROUND

Catheter-related thrombotic complications(TCs) can occur during the long term use of a chronic dialysis catheter (CDC), including fibrin sheath (FS), mural thrombosis (MT), venous thrombosis (VT), and intraluminal clots (IC), which has not been reported with MRI. The aim of our study was to evaluate the determination of catheter tip position (TP) and resolution of TCs in patients with transjugular CDC scheduled into the superior vena cava using high resolution magnetic resonance cholangiopancreatography (HR-MRCP) and T2-weighted imaging (HR-T2WI).

METHODS

The study protocol was approved by the local Research Ethics Committee. Informed consent was obtained from all patients. In total, 41 consecutively enrolled transjugular CDC patients with suspected catheter dysfunction were scanned with HRMRCP and HR-T2WI. The distance from the top to the tip of the catheter and the presence and nature of catheter TCs were assessed by 2 experienced radiologists. Chest x-ray was taken within 1 to 2 days and CDC was withdrawn within 3 to 10 days from those patients with TCs identified by HR-MRI.

RESULTS

A total of 38 subjects successfully underwent HR-MRI, including 13 normal and 25 with TCs (fibrin sheath [FS]: n = 21, mural thrombosis [MT]: n = 7, venous thrombosis [VT]: n = 3, intraluminal clots [IC]: n = 4). There was no significant difference between HR-MRCP and chest x-ray in catheter TP determination (P = .124). Normal catheter appeared as "double eyes" on HR-T2WI and "double tracks" on HR-MRCP. TCs appeared as follows: FS displayed as a "thin ring" (<1mm) around the catheter, MT as patchy hyperintensity and VT as a "thick ring" (>5mm) on HR-T2WI. Unilateral IC appeared as a "single eye" on HR-T2WI and a "single track" on HR-MRCP (n = 3). Bilateral IC appeared as neither "eye" nor "track" (n = 1). Catheter withdrawal confirmed FS (n = 16), MT (n = 6), VT (n = 1), and IC (n = 4).

CONCLUSION

HR-MRCP and HR-T2WI are promising methods for visualizing TP and TCs in CDC patients, and are helpful in adjusting the treatment plan and avoiding the risk of pulmonary embolism.

Hemodialysis Tunneled Catheter Noninfectious Complications

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.

Hemodialysis Tunneled Catheter Noninfectious Complications

Noninfectious hemodialysis catheter complications include catheter dysfunction, catheter-related thrombus, and central vein stenosis. The definitions, causes, and treatment strategies for catheter dysfunction are reviewed below. Catheter-related thrombus is a less common but serious complication of catheters, requiring catheter removal and systemic anticoagulation. In addition, the risk factors, clinical manifestation, and treatment options for central vein stenosis are outlined.

Treatment of Tunneled Dialysis Catheter Malfunction: Revision versus Exchange

Introduction

Exchange procedures involve tunneled dialysis catheter (TDC) removal and exchange over a wire, using the same exit site and venotomy site. Diagnostic imaging or intervention was generally not performed in exchange procedures. Revision procedures involve placement of new TDC using the previous venotomy site and a new tunnel and exit site. The majority of revisions usually include diagnostic imaging and intervention in the central circulation if needed.

Methods

A retrospective single review of 70 patients who underwent 97 TDC replacements from 2010 to early 2012 because of catheter malfunction was evaluated for either infection or malfunction within 30 days of the procedure.

Results

There were 41 exchanges and 56 revisions out of the 97 procedures performed. There were eight infections (documented by positive blood culture) in the exchanges (19.5%) and one in the revision group (1.8%). The need for an additional procedure due to malfunction was 10 in the exchange (24.4%) and 10 (17.8%) in the revision group.

Conclusions

Revision is a clearly superior procedure with regard to infection and more data need to be gathered as to whether it will decrease repeat procedures.

Infective Endovascular Fibrin Sheath Vegetations—A New Cause of Bacteremia Detected by Transesophageal Echocardiogram

BACKGROUND/PURPOSE

A fibrin sheath is a circumferential sleeve of endothelium that forms around the surface of implanted central venous catheters and frequently remains intact within the lumen of the vein after removal of the catheters. We describe a new entity of infective endovascular fibrin sheath vegetations.

METHODS

Records of patients hospitalized and found to have echocardiographically identified infective endovascular fibrin sheath vegetations at our institution, Cedars Sinai Medical Center, from 2010 to 2014 were reviewed for clinical variables of interest. Collected data included medical history, physical examination findings, laboratory, microbiology, imaging, a prior history of presence of a central venous catheter, treatment, and outcomes.

RESULTS

Eleven patients (20-77 years old; 6 women, 5 men) were found by transesophageal echocardiogram to have fibrin sheaths. All of the infective endovascular fibrin sheath vegetations were identified by transesophageal echocardiography, while none were seen with transthoracic echocardiography. Eight of 11 patients were critically ill, septic, and admitted to the Intensive Care Unit. Six patients were intubated and required vasopressor therapy. All cases were treated with long-term antibiotics, 5 were treated with anticoagulation, and 2 were treated with mechanical thrombectomy. Mortality was 36%, with death ranging from 44 to 251 days after diagnosis. The 90-day hospital readmission rate was 55%.

CONCLUSION

Infective endovascular fibrin sheath vegetations are not seen with transthoracic echocardiogram. They may be overlooked and not seen by transesophageal echocardiogram unless the vena cava is adequately imaged. Moreover, fibrin sheath vegetations are associated with a high morbidity and mortality. They should be treated as a serious endovascular infection and managed with aggressive medical or interventional therapies, or both.

Fibrin sheath formation and intimal thickening after catheter placement in dog model: role of hemodynamic wall shear stress

PURPOSE

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.

Tunneled Dialysis Catheter Exchange with Fibrin Sheath Disruption is not Associated with Increased Rate of Bacteremia

Purpose

Tunneled dialysis catheters are the most common form of vascular access among incident dialysis patients in the United States. Fibrin sheath formation is a frequent cause of late catheter dysfunction requiring an exchange procedure with balloon disruption of the fibrin sheath. It is unknown whether fibrin sheath disruption is associated with increased incidence of bacteremia or catheter failure.

Methods

We reviewed all tunneled dialysis catheter exchange procedures at the University of Wisconsin between January 2008 and December 2011. The primary outcome was incidence of bacteremia, defined as positive blood cultures within 2 weeks of the procedure. Catheter failure, requiring intervention or replacement, was examined as a secondary outcome. Baseline characteristics examined included diabetic status, gender, race and age.

Results

A total of 163 procedures were reviewed; 67 (41.1%) had fibrin sheath disruption and 96 did not. Bacteremia occurred in 4.5% (3/67) of those with and 3.1% (3/97) of those without fibrin sheath disruption (p=0.65). Fibrin sheath disruption was not significantly associated with the risk of catheter failure (adjusted hazard ratio [aHR]=1.34; 95% confidence interval [CI]: 0.87-2.10; p=0.18). Diabetes was associated with greater risk of catheter failure (aHR=1.88; 95% CI: 1.19-2.95; p=0.006), whereas higher age was associated with a lower risk of catheter failure (aHR per 10 years=0.83; 95% CI: 0.72-0.96; p=0.01).

Conclusions

This study demonstrates that there is no significant increase in bacteremia and subsequent catheter dysfunction rates after fibrin sheath disruption compared to simple over the wire exchange. These results are encouraging given the large numbers of patients utilizing tunneled catheters for initial hemodialysis access and the known rates of fibrin sheath formation leading to catheter failure.