Percutaneous fibrin sheath stripping versus transcatheter urokinase infusion for malfunctioning well-positioned tunneled central venous dialysis catheters: a prospective, randomized trial

Aetiology and management of persistent withdrawal occlusion in venous ports in oncology patients

INTRODUCTION

Persistent withdrawal occlusion (PWO) is a specific catheter malfunction characterized by the inability to withdraw blood through the device. The most common cause of PWO in ports is the presence of a fibroblastic sleeve (FS). If malfunction occurs, medication can be applied incorrectly with the increased risk of complications.

METHODS

One hundred seventy-seven cases of PWO in venous ports were managed. We focused on evaluating the cause of PWO, the frequency of occurrence of FS, and the options to address the malfunction. The patients underwent fluoroscopy with a contrast agent administration. Mechanical disruption (MD) with a syringe of saline using the flush method was used; in case of its failure, subsequent administration of a lock solution with taurolidine and urokinase, or low-dose thrombolysis with alteplase was indicated. Demographic data were compared with a control group.

RESULTS

A significantly higher proportion of female patients was found in the cohort of patients with PWO (80.3% vs 66.3%, p = 0.004), dominantly patients with ovarian cancer (12.8% vs 4.8%, p = 0.022). No effect of the cannulated vein or the type of treatment on the incidence of PWO was demonstrated. The presence of FS was verified in 70% of cases. MD with a syringe was successful in 53.5% of cases. A significantly shorter time to referral (3 weeks) was demonstrated with successful management. The overall success rate of achieving desobliteration by MD alone or in combination with a thrombolytic (urokinase or alteplase) administration was 97.4%.

CONCLUSION

We created a method for resolving PWO using MD +/- application of thrombolytics with 97.4% success rate. Current evidence showed that FS is not likely to be affected by thrombolytic drugs; however, we have ascertained an effect of these drugs, proposing a hypothesis of microthrombotic events at the tip of the catheter if fibroblastic sleeve is present.

Comparative effectiveness and safety among different tip-design hemodialysis long-term catheters: A meta-analysis

PURPOSE

The aim of this meta-analysis is to compare effectiveness and safety among different tip-design long-term hemodialysis (HD) catheters.

MATERIALS AND METHODS

PubMed, Embase, and Cochrane Library databases were searched until 8 December 2021 to identify randomized controlled trials (RCTs) and cohort studies comparing step-tip, split-tip, or symmetrical-tip design catheters in patients undergoing HD will be included. The Cochrane Risk of Bias tool and the Newcastle-Ottawa Scale were used to evaluate the quality of RCTs and cohort studies. Data extracted from the articles were integrated to determine mean effective blood pump velocity (Qb), blood recirculation rates, secondary patency, catheter-related infection, catheter-related blood stream infection (CRBSI), thrombosis rates, and all-cause mortality for the three tip-designs. We performed meta-analysis on dichotomous outcomes using a random-effects model to evaluate risk ratios (RRs) and 95% confidence intervals (Cls). The effect sizes of continuous outcomes were reported as the mean difference (MD). Sensitivity and subgroup analyses were also performed. The study was registered in the PROSPERO (CRD42021297069).

RESULTS

Six RCTs and 11 cohort studies of 2617 individuals were included in our meta-analysis, of which 1088 individuals inserted split-tip catheters, 897 individuals inserted step-tip catheters and 650 received symmetrical-tip design catheters. Sym-tip performed better in mean Qb (MD = 43.85, 95% Cl = 18.13-69.56, p = 0.0008) than step-tip. Split-tip had better outcomes vs step-tip in blood recirculation (RR = 3.44, 95% Cl = 2.49-4.39, p < 0.00001). Sym-tip had significantly better outcomes compared with step-tip (RR = 0.28, 95%Cl = 0.09-0.81, Z = 2.34, p = 0.02) and split-tip (RR = 0.19, 95% Cl = 0.09-0.43, p < 0.0001) in thrombotic events. No significant difference was found in secondary patency, infection rates, CRBSI, and all-cause mortality among the three tip-designs.

CONCLUSION

The sym-tip of tunneled cuffed catheters performed better mean Qb, lower thrombotic events, and lower blood recirculation when blood line reversed, which may have an advantage over other two catheter-tips.

Safety and Effectiveness of Fibrin Sheath Stripping of Pediatric Chest Ports

PURPOSE

To report the safety and effectiveness of fibrin sheath stripping of pediatric chest ports.

MATERIALS AND METHODS

Fibrin sheath stripping procedures for pediatric chest ports between 2018 and 2023 were retrospectively reviewed. The treatment indication was the inability to aspirate blood from the port. The technical success, adverse events, days of primary and secondary service intervals, fluoroscopy time, and fluoroscopy dose were recorded.

RESULTS

Fibrin sheath stripping procedures were performed in 15 patients for a total of 18 procedures. All patients treated with fibrin sheath stripping had failed fibrinolytic treatment and a preprocedural fluoroscopy examination suggestive of fibrin sheath before attempting stripping. All fibrin sheath stripping procedures were technically successful. The median and mean total days of primary service interval from the date of port placement to the date of suspected fibrin sheath were 666 and 617 days, respectively. The median and mean total number of days of secondary service interval were 385 and 561 days, respectively. The mean fluoroscopy time was 16.9 minutes. The mean fluoroscopy air kerma was 29.8 mGy. No adverse events were observed.

CONCLUSIONS

Fibrin sheath stripping is a safe and effective minimally invasive option to maintain the function of pediatric chest ports.

Guidelines for Central Venous Port Placement and Management (Abridged Translation of the Japanese Version)

The central venous port has been widely used for patients who require long-term intravenous treatments, and the number of palcement has been increasing. The Japanese Society of Interventional Radiology developed a guideline for central venous port placement and management to provide evidence-based recommendations to support healthcare providers in the decision-making process regarding the central venous port. The guideline consisted of two parts: (i) a comprehensive review of topics including preoperative preparation, techniques for placement or removal, complications, and maintenance methods and (ii) recommendations for the six clinical questions regarding blood vessels for central venous port placement, port implantation site, prophylactic antibiotic therapy, imaging guidance for puncture, disinfectant prior to accessing the central venous port, and the optimal procedure at the end of drug administration via the central venous port, generated on the basis of the rating quality of evidence by systematic review.

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.

Vascular access in children requiring maintenance haemodialysis: a consensus document by the European Society for Paediatric Nephrology Dialysis Working Group

BACKGROUND

There are three principle forms of vascular access available for the treatment of children with end stage kidney disease (ESKD) by haemodialysis: tunnelled catheters placed in a central vein (central venous lines, CVLs), arteriovenous fistulas (AVF), and arteriovenous grafts (AVG) using prosthetic or biological material. Compared with the adult literature, there are few studies in children to provide evidence based guidelines for optimal vascular access type or its management and outcomes in children with ESKD.

METHODS

The European Society for Paediatric Nephrology Dialysis Working Group (ESPN Dialysis WG) have developed recommendations for the choice of access type, pre-operative evaluation, monitoring, and prevention and management of complications of different access types in children with ESKD.

RESULTS

For adults with ESKD on haemodialysis, the principle of "Fistula First" has been key to changing the attitude to vascular access for haemodialysis. However, data from multiple observational studies and the International Paediatric Haemodialysis Network registry suggest that CVLs are associated with a significantly higher rate of infections and access dysfunction, and need for access replacement. Despite this, AVFs are used in only ∼25% of children on haemodialysis. It is important to provide the right access for the right patient at the right time in their life-course of renal replacement therapy, with an emphasis on venous preservation at all times. While AVFs may not be suitable in the very young or those with an anticipated short dialysis course before transplantation, many paediatric studies have shown that AVFs are superior to CVLs.

CONCLUSIONS

Here we present clinical practice recommendations for AVFs and CVLs in children with ESKD. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system has been used to develop and GRADE the recommendations. In the absence of high quality evidence, the opinion of experts from the ESPN Dialysis WG is provided, but is clearly GRADE-ed as such and must be carefully considered by the treating physician, and adapted to local expertise and individual patient needs as appropriate.

Pipe-Cleaning Plugged Portacaths: How to Unclog an Implanted Port After Development of a Fibrin Sheath

Industry has long fought the battle to design a vascular catheter that is less thrombogenic. Indwelling catheters provide long-term central venous access, but they develop fibrin sheaths as the vascular system recognizes them as foreign bodies. Peripheral catheters and central catheters can be changed over a guidewire when they form a fibrin sheath or otherwise malfunction. However, totally implantable venous access devices such as a port cannot be easily exchanged over a wire. Therefore, when a port malfunctions, thrombolytics are usually the only option attempted before the port is explanted and a new site is prepared for access. We present a minimally invasive technique demonstrating port salvage that does not require explant.

Shanghai expert consensus on totally implantable access ports 2019

Totally implantable access ports (TIAPs) are used for patients with poor peripheral vascular support requiring central venous access. In recent years, TIAPs have been gradually accepted and promoted by patients, doctors, and nurses owing to their advantages of convenient carrying, a long maintenance period, low complications, and a high quality of life for patients. Currently, medical personnel that handle TIAP implantation and management in China are from different areas of healthcare, including surgery, internal medicine, radiology, nurse anesthesia, vascular access, etc., and many only handle TIAP as a part of their duties. Therefore, the operating procedures and steps for the diagnosis and treatment of complications of TIAP vary from person to person, resulting in different incidence and treatment methods for complications in the implantation and use of TIAP in different medical units. Based on this, we have updated the Shanghai expert consensus on TIAPs from 2015 and explored the diagnosis and treatment procedures of related complications while continuing to emphasize standardized implantation and maintenance.

Managing dysfunctional central venous access devices: a practical approach to urokinase thrombolysis

Tunnelled central venous access devices (CVADs) are defined as any intravenous multipurpose catheters placed within the central veins for use in haemodialysis and administration of blood products or chemotherapy in oncology and haematological conditions. Frequent complications include thrombosis and catheter-related infection, which may lead to significant adverse patient outcomes. Once thrombosis is suspected correction should be attempted empirically with thrombolytic agents. Commonly available thrombolytic agents in the UK include urokinase (Syner-Kinase) and alteplase (Cathflo). It is well recognised that urokinase usage differs widely and concerns were raised by clinicians about the variation of dose regimens nationally. The objective of the CVAD Focus Group was to address this issue and offer guidance in the management of suspected thrombosis of CVAD with urokinase using two algorithms for renal and non-renal dysfunctional CVAD and to audit prospectively the outcomes of intervention.

A novel technique for removing a fibrin sheath from a mediport catheter in the pediatric population

Mediport (also known as port, portacath or Infusaport) is a commonly placed central venous access in pediatric patients. Fibrin sheath formation around the central venous catheter is a common biological response leading to port malfunction in the form of inability to aspirate but preserved capacity for infusion of fluids. If fibrinolytic therapy fails, percutaneous fibrin sheath stripping via transfemoral route or replacement with a new mediport are routine/conventional treatments for a fibrin sheath. We describe a novel technique for removing a fibrin sheath by exteriorizing the catheter through the neck entry site, stripping the fibrin sheath from the catheter manually under sterile conditions and replacing the catheter via a peel-away sheath introduced through the same skin incision as an alternative to complete port replacement or attempted catheter stripping.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

Location and structure of fibrous sheath formed after placing a tunneled hemodialysis catheter in a large pig model

BACKGROUND AND OBJECTIVES

We evaluated the location and structure of the fibrous sheath formed after the placement of tunneled, cuffed hemodialysis catheters in large animals, 70 kg pigs. We focused on describing the location of the fibrous sheath in relation to the catheter. Its location explains the fibrous sheath's ability to cause catheter dysfunction by covering the catheter exit ports located at the catheter's tip.

DESIGN

We used three animals. Each animal had a tunneled, cuffed, 15-French diameter hemodialysis catheter placed in the external jugular vein, with the tip at the junction of the superior vena cava and the right atrium. Two animals were sacrificed at 5 weeks and one animal at 17 weeks after catheter placement. The catheter and surrounding tissues were removed in one block. The fibrous sheath was dissected and longitudinally cut along the catheter to evaluate its extension in relation to the catheter. Relevant portions of the fibrous sheath were sent for pathology examination.

RESULTS

The fibrous sheath covered the catheter in its entire length and circumference. It started at the entry site and continued without any interruption along the entire length of the catheter, including the tip. Its average thickness is 1 mm and has an inner cellular/inflammatory layer comprising lymphocytes, plasma cells, neutrophils, macrophages, multinucleated giant cells, and spindled cells and an outer layer comprising a mixture of collagen and fibroblasts.

CONCLUSION

Our model showed that the fibrous sheath forms around all catheters and covers them in their entire length and circumference without any gaps.

Salvage Insertion of Tunneled Central Venous Catheters in the Internal Jugular Vein after Accidental Catheter Removal

Purpose

Tunneled catheters are widely used for intermediate to long-term hemodialysis (HD) access, but are prone to several complications that can require catheter replacement. Replacing malfunctioning catheters with a new line, placed in a different access site, can lead to problems with multiple vein occlusions. This has led many nephrologists to continue using the same vein as long as possible by guidewire catheter exchanges, to preserve other veins for future use. We describe a guidewire exchange technique for the Ash-Split catheter in the internal jugular vein.

Methods

In three patients, the exchange was performed because of partial catheter removal, as evidenced by the outward dislocation of the Dacron cuff. In these patients, the guidewire was inserted through the catheter. In two additional patients, the catheter had been completely removed by accident: the replacement of the dislodged tunneled venous catheters was attempted 5 hr and 1 day after accidental removal. In these patients, the guidewire was inserted through the previous tunnel. After guidewire placement, a skin incision was made in the supraclavicular region. The metal guidewire was easily located inside the fibrous structure that had previously surrounded the catheter. The guidewire was then extracted from the subcutaneous tunnel and used to insert a new catheter safely and easily after creating a new tunnel. Patients were routinely given antibiotic prophylaxis (1 g of cefazolin) immediately before the procedure. A strict aseptic technique was used, including several sterile glove changes.

Results

No infections developed following this procedure, which has the potential for bacterial contamination. All procedures were successful. Only in one patient did we have to convert to a different catheter: it was not possible to replace the old Ash-Split catheter with the same dual-lumen catheter because of difficulties in inserting the peel away introducer-catheter complex. In this patient, rather than forcing it with larger dilators or trying to disrupt the fibrin sheath with balloon dilatation, a single lumen Tesio catheter was successfully placed. In both patients who completely lost the previous catheter, the guidewire was readily reinserted through the subcutaneous tunnel into the vein. Catheter function was excellent in all patients, with a test blood flow rate on the 1st catheter use >350 ml/min.

Conclusions

We described a new method for catheter exchange, which allows the easy insertion of a new catheter and the creation of a new and safer subcutaneous tunnel. In addition, we demonstrated that in cases of complete catheter removal, it is possible to reinsert a catheter in the same vein through a guidewire, even when reinsertion was attempted up to 1 day later.

Interventions for treating central venous haemodialysis catheter malfunction

BACKGROUND

Adequate haemodialysis (HD) in people with end-stage kidney disease (ESKD) is reliant upon establishment of vascular access, which may consist of arteriovenous fistula, arteriovenous graft, or central venous catheters (CVC). Although discouraged due to high rates of infectious and thrombotic complications as well as technical issues that limit their life span, CVC have the significant advantage of being immediately usable and are the only means of vascular access in a significant number of patients. Previous studies have established the role of thrombolytic agents (TLA) in the prevention of catheter malfunction. Systematic review of different thrombolytic agents has also identified their utility in restoration of catheter patency following catheter malfunction. To date the use and efficacy of fibrin sheath stripping and catheter exchange have not been evaluated against thrombolytic agents.

OBJECTIVES

This review aimed to evaluate the benefits and harms of TLA, preparations, doses and administration as well as fibrin-sheath stripping, over-the-wire catheter exchange or any other intervention proposed for management of tunnelled CVC malfunction in patients with ESKD on HD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 17 August 2017 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all studies conducted in people with ESKD who rely on tunnelled CVC for either initiation or maintenance of HD access and who require restoration of catheter patency following late-onset catheter malfunction and evaluated the role of TLA, fibrin sheath stripping or over-the-wire catheter exchange to restore catheter function. The primary outcome was be restoration of line patency defined as ≥ 300 mL/min or adequate to complete a HD session or as defined by the study authors. Secondary outcomes included dialysis adequacy and adverse outcomes.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed retrieved studies to determine which studies satisfy the inclusion criteria and carried out data extraction. Included studies were assessed for risk of bias. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using GRADE.

MAIN RESULTS

Our search strategy identified 8 studies (580 participants) as eligible for inclusion in this review. Interventions included: thrombolytic therapy versus placebo (1 study); low versus high dose thrombolytic therapy (1); alteplase versus urokinase (1); short versus long thrombolytic dwell (1); thrombolytic therapy versus percutaneous fibrin sheath stripping (1); fibrin sheath stripping versus over-the-wire catheter exchange (1); and over-the-wire catheter exchange versus exchange with and without angioplasty sheath disruption (1). No two studies compared the same interventions. Most studies had a high risk of bias due to poor study design, broad inclusion criteria, low patient numbers and industry involvement.Based on low certainty evidence, thrombolytic therapy may restore catheter function when compared to placebo (149 participants: RR 4.05, 95% CI 1.42 to 11.56) but there is no data available to suggest an optimal dose or administration method. The certainty of this evidence is reduced due to the fact that it is based on only a single study with wide confidence limits, high risk of bias and imprecision in the estimates of adverse events (149 participants: RR 2.03, 95% CI 0.38 to 10.73).Based on the available evidence, physical disruption of a fibrin sheath using interventional radiology techniques appears to be equally efficacious as the use of a pharmaceutical thrombolytic agent for the immediate management of dysfunctional catheters (57 participants: RR 0.92, 95% CI 0.80 to 1.07).Catheter patency is poor following use of thrombolytic agents with studies reporting median catheter survival rates of 14 to 42 days and was reported to improve significantly by fibrin sheath stripping or catheter exchange (37 participants: MD -27.70 days, 95% CI -51.00 to -4.40). Catheter exchange was reported to be superior to sheath disruption with respect to catheter survival (30 participants: MD 213.00 days, 95% CI 205.70 to 220.30).There is insufficient evidence to suggest any specific intervention is superior in terms of ensuring either dialysis adequacy or reduced risk of adverse events.

AUTHORS' CONCLUSIONS

Thrombolysis, fibrin sheath disruption and over-the-wire catheter exchange are effective and appropriate therapies for immediately restoring catheter patency in dysfunctional cuffed and tunnelled HD catheters. On current data there is no evidence to support physical intervention over the use of pharmaceutical agents in the acute setting. Pharmacological interventions appear to have a bridging role and long-term catheter survival may be improved by fibrin sheath disruption and is probably superior following catheter exchange. There is no evidence favouring any of these approaches with respect to dialysis adequacy or risk of adverse events.The current review is limited by the small number of available studies with limited numbers of patients enrolled. Most of the studies included in this review were judged to have a high risk of bias and were potentially influenced by pharmaceutical industry involvement.Further research is required to adequately address the question of the most efficacious and clinically appropriate technique for HD catheter dysfunction.

Fibrin sheaths in central venous port catheters: treatment with low-dose, single injection of urokinase on an outpatient basis

Purpose

Evaluation of the efficacy of single-shot, low-dose urokinase administration for the treatment of port catheter-associated fibrin sheaths.

Methods

Forty-six patients were retrospectively evaluated for 54 episodes of port catheter dysfunction. The presence of a fibrin sheath was detected by angiographic contrast examinations. On an outpatient basis, patients subsequently received thrombolysis consisting of a single injection of urokinase (15.000 IU in 1.5 mL normal saline) through the port system. A second attempt was made in cases of treatment failure. Patients were followed up for technical success, complications and long-term outcome.

Results

Port dysfunction occurred at a median of 117 days after implantation (range: 7–825 days). The technical success after first port dysfunction by thrombolysis was 87% (40/46); thereof, initial thrombolysis was effective in 78% (36/46). Nine patients (20%) received a second dose of urokinase after previous treatment failure. Follow-up was available for 26 of 40 patients after successful thrombolysis. In 8 of these, rethrombosis occurred after a median of 98 days (range: 21–354 days), whereby rethrombolysis was effective in 5 of 7 (63%) patients. The overall success of all thrombolyses performed was 70% (45/64). No procedure-related technical or clinical complications occurred. After first favorable thrombolysis, a Kaplan–Meier analysis yielded a 30-, 90- and 180-day probability of patency of 96%, 87% and 81%.

Conclusion

Thrombolytic therapy on an outpatient basis appears to be a safe and efficient. Three-month patency rates are comparable to more invasive treatment options, including catheter exchange over a guide wire and percutaneous fibrin sheath stripping.

A Novel Technique Using a Protection Filter During Fibrin Sheath Removal for Implanted Venous Access Device Dysfunction

With the increased use of implanted venous access devices (IVADs) for continuous long-term venous access, several techniques such as percutaneous endovascular fibrin sheath removal, have been described, to maintain catheter function. Most standard techniques do not capture the stripped fibrin sheath, which is subsequently released in the pulmonary circulation and may lead to symptomatic pulmonary embolism. The presented case describes an endovascular technique which includes stripping, capture, and removal of fibrin sheath using a novel filter device. A 64-year-old woman presented with IVAD dysfunction. Stripping was performed using a co-axial snare to the filter to capture the fibrin sheath. The captured fragment was subsequently removed for visual and pathological verification. No immediate complication was observed and the patient was discharged the day of the procedure.

Patency and Complications of Translumbar Dialysis Catheters

Translumbar tunneled dialysis catheter (TLDC) is a temporary dialysis access for patients exhausted traditional access for dialysis. While few small studies reported successes with TLDC, additional studies are warranted to understand the short- and long-term patency and safety of TLDC. We conducted a retrospective analysis of adult patients who received TLDC for hemodialysis access from June 2006 to June 2013. Patient demographics, comorbid conditions, dialysis details, catheter insertion procedures and associated complications, catheter patency, and patient survival data were collected. Catheter patency was studied using Kaplan-Meier curve; catheter functionality was assessed with catheter intervals and catheter-related complications were used to estimate catheter safety. There were 84 TLDCs inserted in 28 patients with 28 primary insertions and 56 exchanges. All TLDC insertions were technically successful with good blood flow during dialysis (>300 ml/minute) and no immediate complications (major bleeding or clotting) were noted. The median number of days in place for initial catheter, secondary catheter, and total catheter were 65, 84, and 244 respectively. The catheter patency rate at 3, 6, and 12 months were 43%, 25%, and 7% respectively. The main complications were poor blood flow (40%) and catheter-related infection (36%), which led to 30.8% and 35.9% catheter removal, respectively. After translumbar catheter, 42.8% of the patients were successfully converted to another vascular access or peritoneal dialysis. This study data suggest that TLDC might serve as a safe, alternate access for dialysis patients in short-term who have exhausted conventional vascular access.

Management of dysfunctional catheters and tubes inserted by interventional radiology

Minimally invasive percutaneous interventions are often used for enteral nutrition, biliary and urinary diversion, intra-abdominal fluid collection drainage, and central venous access. In most cases, radiologic and endoscopic placement of catheters and tubes has replaced the comparable surgical alternative. As experience with catheters and tubes grows, it becomes increasingly evident that the interventional radiologist needs to be an expert not only on device placement but also on device management. Tube dysfunction represents the most common complication requiring repeat intervention, which can be distressing for patients and other health care professionals. This manuscript addresses the etiologies and solutions to leaking and obstructed feeding tubes, percutaneous biliary drains, percutaneous catheter nephrostomies, and drainage catheters, including abscess drains. In addition, we will address the obstructed central venous catheter.

Vascular Access for Placement of Tunneled Dialysis Catheters for Hemodialysis: A Systematic Approach and Clinical Practice Algorithm

The role of interventional radiology in the overall management of patients on dialysis continues to expand. In patients with end-stage renal disease (ESRD), the use of tunneled dialysis catheters (TDCs) for hemodialysis has become an integral component of treatment plans. Unfortunately, long-term use of TDCs often leads to infections, acute occlusions, and chronic venous stenosis, depletion of the patient's conventional access routes, and prevention of their recanalization. In such situations, the progressive loss of venous access sites prompts a systematic approach to alternative sites to maximize patient survival and minimize complications. In this review, we discuss the advantages and disadvantages of each vascular access option. We illustrate the procedures with case histories and images from our own experience at a highly active dialysis and transplant center. We rank each vascular access option and classify them into tiers based on their relative degrees of effectiveness. The conventional approaches are the most preferred, followed by alternative approaches and finally the salvage approaches. It is our intent to have this review serve as a concise and informative reference for physicians managing patients who need vascular access for hemodialysis.

Tunnelled central venous catheter–induced thrombosis: a rare case of superior vena cava syndrome

Thrombotic venous obstruction in patients with a tunnelled central venous catheter is a cause of superior vena cava syndrome that is not routinely encountered by emergency physicians. Diagnosis requires identifying patients at risk (e.g., those under treatment for cancer and those who have a tunnelled central venous catheter), recognizing the signs and symptoms of superior vena cava syndrome, usually dyspnea and dilated neck or thoracic veins, and imaging the venous obstruction using computer tomography or sonography. Management involves anticoagulation and local thrombolytic administration. We report the case of a 28-year-old woman who presented with a 2-day history of face, chest and bilateral arm swelling who had been receiving maintenance chemotherapy for acute lymphoblastic leukemia through a Hickman® catheter. This case demonstrates the need to be vigilant for thrombus formation in patients with long-term, indwelling central venous catheters.

Mechanical thrombolysis of thrombosed central venous port

PURPOSE

To evaluate the effectiveness of a mechanical thrombolysis for thrombosed central venous port (CVP).

METHODS

A total of 38 patients (22 women and 16 men, median age of 55 years) were referred to our interventional unit for thrombosed implanted CVPs. The period between CVP implantation and the initial suspicion of mechanical complication varied from 2 to 35 months (mean 11.5 months) and the interval since last use of the CVP averaged 47 days (range 28-324 days). Our mechanical thrombolysis technique was performed to fragment thrombus in the port chamber by whirling the floppy tip of 0.018-inch hair-wire. Only 19-gauge noncoring needle and 0.018-inch hire-wire were used without cut-down. After removing the hair-wire and placing a second needle, the fragmented thrombi was slowly aspirated with a negative pressure and the remnant thrombus was flushed out by pushing a saline fluid. The degree of fragmentation of thrombus was evaluated with posttreatment angiography; incomplete lysis was defined as more than 50 % of thrombus remaining, significant lysis was 10-50 % of initial thrombosis remaining, and near-complete lysis was less than 10 % thrombus remaining.

RESULTS

We observed near-complete lysis in 22 patients (58 %), significant lysis in 14 patients (37 %), and incomplete lysis in two patients (5 %). The technical success rate was 82 % (31 of 38 patients). There were no major or minor complications in the recovery room during a 30-min observation period or late complications at outpatient follow-up.

CONCLUSION

A mechanical thrombolysis technique can be used to dissolve thrombus effectively from thrombosed implanted CVP on an outpatient basis.

Self-centering, split-tip catheter has better patency than symmetric-tip tunneled hemodialysis catheter: single-center retrospective analysis

The performance and safety of a new self-centering, split-tip hemodialysis tunneled catheter was compared with a symmetric-tip catheter. The new catheter has a greater separation between the arterial and venous tips, with dual apertures designed to permanently face the center of the blood vessel. The design is intended to improve dialysis efficiency by increasing flow rates while decreasing recirculation, fibrin sheath formation, thrombosis, and vessel wall occlusions. The study results indicated that the self-centering, split-tip catheter had statistically greater patency after 3 months with similar clearance, blood flow, and safety.

Vascular access in therapeutic apheresis: update 2013

This review addresses the types of vascular access available for patients who need therapeutic apheresis (TA). As in hemodialysis, vascular access for TA is chosen based on type of procedure prescribed, the patient's vascular anatomy, the acuity, frequency and duration of treatment, and the underlying disease state. The types of access available include peripheral vein cannulation, central venous catheters: including nontunneled and tunneled catheters, arterio-venous grafts and arterio-venous fistulas. Peripheral veins and central venous catheters are most frequently utilized for the acute administration of TA, and may be used over a period of weeks to months. Arterio-venous grafts and fistulas are not commonly used in TA procedures, but are an option in patients with an anticipated long course of TA, usually for a period of several months or years. The types and frequency of complications associated with various types of vascular access, including: access dysfunction and infections are reviewed, and strategies for their prevention and management are offered.

Imaging and management of complications of central venous catheters

Central venous catheters (CVCs) provide valuable vascular access. Complications associated with the insertion and maintenance of CVCs includes pneumothorax, arterial puncture, arrhythmias, line fracture, malposition, migration, infection, thrombosis, and fibrin sheath formation. Image-guided CVC placement is now standard practice and reduces the risk of complications compared to the blind landmark insertion technique. This review demonstrates the imaging of a range of complications associated with CVCs and discusses their management with catheter salvage techniques.

[Central venous catheters as access for acute and long-term dialysis]

Central venous dialysis catheters are indispensible as a rapid large lumen access to the blood compartment. If such a central venous catheter is necessary for longer than 2-3 weeks it is better to implant a tunnelled cuffed catheter initially or to switch early from the non-tunnelled acute catheter to a tunnelled cuffed catheter. Tunnelled cuffed catheters can be used for many weeks or even years and the complication rate is less than that of non-tunnelled acute catheters. The proportion of dialysis patients with long-term dialysis using tunnelled cuffed catheters has increased rapidly in recent years and now stands at approximately 20 % in Germany. These catheters are, however, prone to more infectious complications and more thromboses than native arteriovenous fistulas or prosthetic shunts. The mortality of patients with long-term dialysis catheters is also higher than those with arteriovenous shunts. For these reasons central venous catheters will always be regarded as the third choice dialysis access when arteriovenous fistulas are not possible. Catheters are available in a wide variety of designs but the individual advantages are still unclear. In order to avoid short-term and long-term complications a variety of measures for implantation and use during dialysis treatment have been developed which make the use safer.

Complications of catheters: tunneled and nontunneled

Central venous catheters for hemodialysis remain an indispensable modality of vascular access in the United States. Despite strong recommendations by the NKF-KDOQI guidelines to reduce the dependence on catheters, > 80% of all patients initiate hemodialysis using a central venous catheter. Although the tunneled dialysis catheters have some advantages, their disadvantages are many and often dwarf the miniscule advantages. This review is intended to discuss the complications--both acute and chronic--related to the use of tunneled dialysis catheters for hemodialysis access.

Evaluation and management of central venous access complications

Venous access is 1 of the most common interventional procedures in the USA. Using image guidance in the last 2 decades, obtaining venous access has become increasingly routine, and the complications commonly associated with the procedure have significantly decreased. However, interventional radiologists still encounter both early and late complications routinely associated with both central and peripherally inserted access devices. This article discusses the most common and some unusual complications seen with the placement of these devices. We also briefly discuss the management of these complications.

Balloon Angioplasty for Disruption of Tunneled Dialysis Catheter Fibrin Sheath

Purpose

Management of failing tunneled hemodialysis catheters, sometimes the only vascular access for hemodialysis, presents a difficult problem. In spite of various techniques having been developed, no consensus has been reached about the preferred technique, associated with the longest catheter patency.

Methods

We report disruption of the fibrin sheath covering dysfunctional tunneled hemodialysis catheter by means of angioplasty, followed by over guidewire catheter exchange.

Results

Following the procedure, the catheter placed in the recovered lumen of the vessel presented correct function.

Conclusions

The described procedure allowed maintenance of vascular access in our patient. Additionally, dilatation of the concomitant central vein stenosis opens an option for another attempt for arteriovenous fistula creation.

Endovascular Treatment of Dysfunctional Hemodialysis Catheters

Hemodialysis-catheter dysfunction is a common clinical condition in nephrology. Like other central venous devices, hemodialysis-catheters show a disposition for partial or complete thrombotic obstruction and fibrin sleeve formation. Thrombolytic infusion is recommended as therapy of first choice. Alternative interventional strategies include over-the-wire catheter exchange, mechanical fibrin sleeve stripping with a snare and angioplastic sleeve disruption. Those approaches show extremely variable results with mediocre long-term patency rates. Therefore, catheter-avoiding strategies should be considered in detail and AV-fistula creation preferred.

Hemodialysis vascular access options in pediatrics: considerations for patients and practitioners

Recent data indicate that the incidence of end-stage renal disease (ESRD) in pediatric patients (age 0-19 years) has increased over the past two decades. Similarly, the prevalence of ESRD has increased threefold over the same period. Hemodialysis (HD) continues to be the most frequently utilized modality for renal replacement therapy in incident pediatric ESRD patients. The number of children on HD exceeded the sum total of those on peritoneal dialysis and those undergoing pre-emptive renal transplantation. Choosing the best vascular access option for pediatric HD patients remains challenging. Despite a national initiative for fistula first in the adult hemodialysis population, the pediatric nephrology community in the United States of America utilizes central venous catheters as the primary dialysis access for most patients. Vascular access management requires proper advance planning to assure that the best permanent access is placed, seamless communication involving a multidisciplinary team of nephrologists, nurses, surgeons, and interventional radiologists, and ongoing monitoring to ensure a long life of use. It is imperative that practitioners have a long-term vision to decrease morbidity in this unique patient population. This article reviews the various types of pediatric vascular accesses used worldwide and the benefits and disadvantages of these various forms of access.

Malfunction of dialysis catheters: management of fibrin sheath and related problems

Suitable central venous access for hemodialysis is frequently required in patients with end-stage renal disease, whenever an arteriovenous fistula or peritoneal dialysis fails or is not a possibility. Ultimately, long-term dialysis via central access may result in dysfunctional catheter with problems such as malpositioning of catheter tip, fibrin sheath formation, thrombosis, infection, and bleeding. The role of interventional radiology is to deliver appropriate treatment to maintain patent and functional access, while minimizing the risk of venous occlusive disease. This article aims at describing different techniques and approaches for management of fibrin sheath associated with malfunctioning tunneled dialysis catheters, as well as to provide scientific evidence from the current literature.

Malfunctioning central venous catheters in children: a diagnostic approach

Central venous access is increasingly becoming the domain of the radiologist, both in terms of the insertion of central venous catheters (CVCs) and in the subsequent management of these lines. This article seeks to provide an overview of the CVC types available for paediatric patients and a more detailed explanation of the spectrum of complications that may lead to catheter malfunction. A standard catheter contrast study or 'linogram' technique is described. The normal appearances of such a study and a detailed pictorial review of abnormal catheter studies are provided, together with a brief overview of how information from catheter investigations can guide the management of catheter complications.

Central venous lines for chronic hemodialysis: survey of the Midwest Pediatric Nephrology Consortium

Central venous lines (CVL) continue to be the most commonly used vascular access device for children on hemodialysis (HD). Despite their frequent use, little is known regarding the frequency of CVL-related intradialytic complications that could interfere with delivery of effective dialysis. To better assess this, we conducted a cross-sectional study of ten HD centers within the Midwest Pediatric Nephrology Consortium. Vascular access was provided by CVL in 61 of the 83 patients (73%) included. CVL dysfunction (defined as reduced blood flows, need for reversed lines, or frequent intradialytic alarms) occurred in 46% in the prior month. Treatment for suspected clots occurred in 16 patients. Intraluminal tissue plasminogen activator (tPA) was the preferred treatment for a suspected clot. The survey also inquired about the preferred treatment for documented clots, and intraluminal tPA was most preferred, followed by CVL stripping, CVL removal, CVL brushing, and systemic tPA. As for preventative strategies, most HD centers locked the CVL with intraluminal heparin in concentrations ranging from 1,000 to 5,000 U/ml. In conclusion, catheter usage rates and complications were highly prevalent in pediatric HD units in this study. As treatment strategies varied greatly, future prospective studies are needed to determine the effectiveness of each individual therapy.

Radiological insertion and management of peritoneovenous shunt

The purpose of the study was to report our experience of the management of complications following the insertion of a peritoneovenous shunt for intractable malignant ascites. From June 1999 to January 2006, 26 patients underwent insertion of a peritoneovenous shunt for ascites by interventional radiologists. We have used ultrasound and shuntography to assist in the diagnosis of the cause of shunt blockage. Successful techniques for the restoration of the shunt function include port- pumping, stripping of any fibrin sheath, and revision of either the venous or peritoneal catheter. The procedure was initially successful in all patients with continued patency until death in 17. A further four patients are still alive with a functioning shunt. There was one rapid postprocedure death resulting from pulmonary edema. Two patients developed pneumothorax, managed successfully with either a chest drain or aspiration. Shunt dysfunction occurred eight times in seven patients. There were five successful revisions in four patients. Overall, shunt patency has been maintained in 80.1% of patients. Shunt dysfunction is seen in a significant number of patients, but successful revision of the shunt can be achieved in the majority.

Current management of vascular access

Optimizing vascular access outcomes remains an ongoing challenge for clinical nephrologists. All other things being equal, fistulas are preferred over grafts, and grafts are preferred over catheters. Mature fistulas have better longevity and require fewer interventions, as compared with mature grafts. The major hurdle to increasing fistula use is the high rate of failure to mature of newly created fistulas. There is a desperate need for enhanced understanding of the mechanisms of failure to mature and the optimal type and timing of interventions to promote maturity. Grafts are prone to frequent stenosis and thrombosis. Surveillance for graft stenosis with preemptive angioplasty may reduce graft thrombosis, but recent randomized clinical trials have questioned the efficacy of this approach. Graft stenosis results from aggressive neointimal hyperplasia, and pharmacologic approaches to slowing this process are being investigated in clinical trials. Catheters are prone to frequent thrombosis and infection. The optimal management of catheter-related bacteremia is a subject of ongoing debate. Prophylaxis of catheter-related bacteremia continues to generate important clinical research. Close collaboration among nephrologists, surgeons, radiologists, and the dialysis staff is required to optimize vascular access outcomes and can be expedited by having a dedicated access coordinator to streamline the process. The goal of this review is to provide an update on the current status of vascular access management.