Summary of Safety and Clinical Performance

Important Information

This Summary of Safety and Clinical Performance (SSCP) is intended to provide public access to an updated summary of the main aspects of the safety and clinical performance of the device. This SSCP is not intended to replace the Instructions for Use as the main document to ensure the safe use of the device, nor is it intended to provide diagnostic or therapeutic suggestions to intended users or patients.

Applicable Documents

1. Device Identification and General Information

Device Trade Name(s): 4.0% DuraLock-C® Catheter Lock Solution 30.0% DuraLock-C® Catheter Lock Solution

Manufacturer Name and Address: Medical Components, Inc. 1499 Delp Drive Harleysville, PA 19438 USA

Manufacturer Single Registration Number (SRN): US-MF-000008230

Basic UDI-DI: 00884908100ME

Medical Device Nomenclature: A02010701 – Prefilled Syringes with Sterile Physiological Solution

Class of Device: Class III according to Rule 14 of Annex VIII of the European Medical Device Regulation EU (MDR) 2017/745

Date First CE Certificate Issued: (4.0%and 30.0%) DuraLock-C was originally sold in ampoules. 30.0% DuraLock-C was first CE marked by DNV in October 2008, and 4.0% DuraLock-C was first CE marked by DNV in September 2010. (4.0% and 30.0%) DuraLock-C was then put into pre-filled syringes. All (3) concentrations of DuraLock-C pre-filled syringes obtained CE mark in August 2012 under DNV. Currently, the Notified Body is BSI. (4.0% and 30.0%) DuraLock-C is now only sold in syringes.

Authorized Representative Name and SRN: European Regulatory Expert Medical Product Service GmbH (MPS) Borngasse 20 35619 Braunfels, Germany SRN: DE-AR-000005009

Notified Body Name and Single Identification Number: BSI Netherlands NB2797

Device Grouping and Variants

(4.0%and 30.0%) DuraLock-C was originally sold in ampoules. 30.0% DuraLock-C was first CE marked by DNV in October 2008, and 4.0% DuraLock-C was first CE marked by DNV in September 2010. (4.0% and 30.0%) DuraLock-C was then put into pre-filled syringes. All (3) concentrations of DuraLock-C pre-filled syringes obtained CE mark in August 2012 under DNV. Currently, the Notified Body is BSI. (4.0% and 30.0%) DuraLock-C is now only sold in syringes.

Variant Devices:

Procedure Trays:

Configurations of Procedure Trays:

2. Intended Use of the Device

Intended Purpose: (4.0% and 30.0%) DuraLock-C® Catheter Lock Solution is intended for use in adult patients with an implanted hemodialysis catheter that is in regular use and where a solution occupying the “dead space” of the lumen between treatments to maintain catheter patency is required, based on the direction of a qualified health professional. DuraLock-C® Catheter Lock Solution is intended to be aspirated prior to treatment and should not be injected into the bloodstream.

Indication(s): (4.0% and 30.0%) DuraLock-C® Catheter Lock Solution is indicated for use in maintaining patency of Hemodialysis Catheters.

Target Population(s): (4.0% and 30.0%) DuraLock-C® Catheter Lock Solution is intended for use in adult patients with an implanted hemodialysis catheter who require a catheter locking solution regardless of gender or race and who do not have any contraindications. (4.0% and 30.0%) DuraLock-C® Catheter Lock Solution is not intended for use in pediatric patients.

Contraindications and/or Limitations:

Patients with known or suspected allergies or hypersensitivity to trisodium citrate.

3. Device Description

Device Name: 4.0% DuraLock-C® Catheter Lock Solution

Description of Device: DuraLock-C® Catheter Lock Solution is supplied as a clear, plastic, prefilled syringe, packaged in a pouch. Each DuraLock-C® prefilled syringe contains a sterile, clear and colorless solution containing sodium citrate; pH is adjusted with citric acid. DuraLock-C® Catheter Lock Solution is intended for short-term use, between 24 hours – 72 hours, as a catheter lock solution. The trisodium citrate within Duralock-C® Catheter Lock Solution prevents thrombus formation by chelating ionized calcium into a soluble complex. Calcium is an integral ion involved in the clotting cascade. Local calcium removal by citrate prevents the activation of clotting cofactors, factor X and prothrombin and the ultimate formation of fibrin. Systemic anticoagulation does not occur. Contents are sterile and non-pyrogenic in unopened, undamaged package. Sterilized by gamma irradiation.

Device Name: 30.0% DuraLock-C® Catheter Lock Solution

Description of Device: DuraLock-C® Catheter Lock Solution is supplied as a clear, plastic, prefilled syringe, packaged in a pouch. Each DuraLock-C® prefilled syringe contains a sterile, clear and colorless solution containing sodium citrate; pH is adjusted with citric acid. DuraLock-C® Catheter Lock Solution is intended for short-term use, between 24 hours – 72 hours, as a catheter lock solution. The trisodium citrate within Duralock-C® Catheter Lock Solution prevents thrombus formation by chelating ionized calcium into a soluble complex. Calcium is an integral ion involved in the clotting cascade. Local calcium removal by citrate prevents the activation of clotting cofactors, factor X and prothrombin and the ultimate formation of fibrin. Systemic anticoagulation does not occur. Contents are sterile and non-pyrogenic in unopened, undamaged package. Sterilized by gamma irradiation.

Materials / Substances in Contact with Patient Tissue:

Sterile, clear and colorless solution containing sodium citrate Supplied as a clear, plastic, prefilled syringe, packaged in a pouch pH is adjusted with citric acid.

Sterile, clear and colorless solution containing sodium citrate Supplied as a clear, plastic, prefilled syringe, packaged in a pouch pH is adjusted with citric acid.

Note:Contents are sterile and non-pyrogenic in unopened, undamaged package. Sterilized by gamma irradiation.

Note:Patients with known or suspected allergies or hypersensitivity to trisodium citrate.

Information on Medicinal Substances in the Device:

How the Device Achieves its Intended Mode of Action: The trisodium citrate within Duralock-C® Catheter Lock Solution prevents thrombus formation by chelating ionized calcium into a soluble complex. Calcium is an integral ion involved in the clotting cascade. Local calcium removal by citrate prevents the activation of clotting cofactors, factor X and prothrombin and the ultimate formation of fibrin. Systemic anticoagulation does not occur.

Sterilization Information: Contents are sterile and non-pyrogenic in unopened, undamaged package. Sterilized by gamma irradiation.

Previous Generations / Variants:

Accessories Intended for Use in Combination with the Device:

Other Devices or Products Intended for Use in Combination with the Device:

4. Risks and Warnings

Residual Risks and Undesirable Effects: Complications and serious adverse events associated with the use of Duralock-C® Catheter Lock Solution are rare and are often related to inadvertent direct infusion of the product through failure to follow instructions for use carefully, especially with respect to priming volumes. Complications of the trisodium citrate within Duralock-C® Catheter Lock Solution are primarily due to systemic effects of hypocalcemia. Systemic hypocalcemia and other citrate-induced metabolic abnormalities may affect cardiac function and may cause severe cardiac arrhythmias. Major bleeding may also occur. Patients in whom Duralock-C® Catheter Lock Solution is often used commonly suffer from end stage renal disease, the presence of which may alter circulating calcium levels, and thus the effect of trisodium citrate infusion may be more pronounced than in a healthy individual. Despite instillation of catheter lock solution in line with the user instructions, some spillage of catheter lock solution might occur resulting in side-effects that are transient and generally mild. Inadvertent over injection has been associated with severe cardiac arrhythmias and should be avoided. Medcomp® has implemented risk management processes to proactively find and mitigate these risks as far as possible without adversely affecting the benefit-risk profile of the device. After mitigation, residual risks and the possibility of adverse events from use of this product remain. This should be weighed against the expected clinical benefit of the DuraLock-C® Catheter Lock Solution.

Warnings and Precautions:

All warnings and precautions have been reviewed against the risk analysis, PMS, and usability testing to validate consistency between the sources of information.

• Warnings listed in the DuraLock-C® Catheter Lock Solution IFUs are as follows:
• Do not inject catheter lock solution into the bloodstream. Inadvertent intravenous administration of DuraLock-C® can result in serious adverse events as described in ‘POTENTIAL COMPLICATIONS’. Only in the event locking solution cannot be aspirated due to catheter dysfunction despite maximal efforts, an attempt to inject 0.1 to 0.2 ml of the luminal content of DuraLock-C® may be carefully considered, but only at a slow rate over several minutes while carefully monitoring the patient. This should be followed by further attempts to aspirate the catheter lock solution (see last bullet point of Warnings).
• Do not use when exact catheter lumen volumes are not known.
• Do not inject more of the solution than the known volume of the catheter lumen.
• Do not apply by direct intravenous injection or added to an infusion.
• Do not use if prefilled syringe solutions show haziness, particulate matter, precipitate, discoloration, or leakage.
• Do not use if the cap on the syringe is not intact or damaged.
• Do not use if package is opened or damaged or the expiration date located on pouch and syringe label has passed.
• Do not re-use. Single use only. Re-use of single use devices creates a potential risk of contamination. This may lead to patient infection, which may cause illness or death of the patient or user.
• Do not flush existing catheter lock solution into the patient. Only in the event locking solution cannot be aspirated due to catheter dysfunction despite maximal efforts, an attempt to inject 0.1 to 0.2 ml of the luminal content of DuraLock-C® may be carefully considered, but only at a slow rate over a minute while carefully monitoring the patient. This should be followed by further attempts to aspirate the catheter lock solution. If both lumens cannot be aspirated, leave several minutes between the first and the second lumen. If the patient mentions side effects as described in ‘POSSIBLE SIDE EFFECTS’ the injection should be stopped. Precautions listed in the DuraLock-C® Catheter Lock Solution IFUs are as follows:
• For patients with severe liver failure or significantly reduced muscle perfusion, consider one or a combination of the following interventions: using lower concentrations of trisodium citrate, implementing close monitoring for diminished citrate clearance, or employing an alternative locking solution. Medical consultation is strongly recommended in these cases.
• In patients with hypocalcemia or hypomagnesemia, 30.0% DuraLock-C® has to be used cautiously. Consider one or a combination of the following interventions: using lower concentrations of trisodium citrate or employing an alternative locking solution (Honore et al., 2018). Medical consultation is strongly recommended in these cases.
• If a patient reports side effects listed in the 'POSSIBLE SIDE EFFECTS' section, these symptoms could be due to a reduced effective priming volume of the catheter, possibly caused by biofilm or tip thrombus. In such cases, consider gradually reducing the locking volume by 0.1mL per session and continue to monitor the patient for symptoms.
• If catheter is not sufficiently locked, clots can form and thrombosis may occur.
• For use with adult patients only.
• Use aseptic technique.
• For prescription use only and to be used by a skilled or trained medical professional only.
• Before using, ensure that catheter lumen, extensions and luer do not contain cracks, swelling or other signs of damage before and after each treatment session.
• If skin contact occurs, clean per facility’s procedures.
• Based on experimental animal studies and limited human experience, citric acid is not expected to increase the risk of birth defects (Reprotox 2020). It should be noted, however, that DuraLock-C® has not been tested in pregnant and/or lactating women.

Other Relevant Aspects of Safety: The overall complaints / sales numbers for a period of 01 May 2024 to 30 April 2025 for DuraLock-C® Catheter Lock Solution are listed below by concentration: 4.0% DuraLock-C®: There were 0 complaints for 1,579,564 units sold, giving an overall complaint rate of 0.000%. 30.0% DuraLock-C®: There were 0 complaints for 177,340 units sold, giving an overall complaint rate of 0.000%. 46.7% DuraLock-C®: There were 2 complaints for 78,660 units sold, giving an overall complaint rate of 0.0002%. For a period from 01 May 2024 to 30 April 2025, there were 0 reportable events (none reported in the EU region). There were no death-related events. No events resulted in field safety corrective actions or recalls during the review period.

5. Summary of Clinical Evaluation and Post-Market Clinical Follow-Up (PMCF)

Summary of Clinical Data Related to Subject Device

The case numbers above are representative of the total number of catheters that were used in conjunction with DuraLock-C® Catheter Lock Solution. It is estimated that the results of PMCF activities are based on 13,647 4.0% DuraLock-C® instillations and 509,982 30.0% DuraLock-C® instillations. Clinical performance and safety were measured using parameters including but not limited to dwell time and adverse event rates. There were no unforeseen adverse events or other high occurrences of adverse events detected in any of the clinical activities.

Summary of Clinical Data Related to the Equivalent Device

An equivalent device was not used for the device’s clinical evaluation.

Summary of Clinical Data from Pre-Market Investigations (if applicable)

No pre-market clinical devices were used for the device’s clinical evaluation.

Summary of Clinical Data from Other Sources

Source:Summary of Published Literature

Clinical evidence literature searches have found no articles relating to DuraLock-C® 4.0% and one retrospective study (Miller et al., 2025) relating to DuraLock-C® 30.0% representing 10,689 specific cases. Miller et al., 2025 analyzes the same cases as PMCF_DLOCK_214. Three published literature articles are known to the manufacturer representing 303 46.7% DuraLock-C® (discontinued in May 2024) specific cases. The articles include two randomized controlled trials (Power et al., 2009, Hermite et al., 2012) and one retrospective cohort study (Parienti et al., 2014). Bibliography: Hermite L, Quenot J-P, Nadji A, et al. Sodium citrate versus saline catheter locks for non-tunneled hemodialysis central venous catheters in critically ill adults: a randomized controlled trial. Intensive Care Med. 2012;38(2):279-285. doi:10.1007/s00134-011-2422-y Miller, G., Feuersenger, A., Ogujiofor, K., Arens, H. J., Blanco, M., Fatima, R., & Zabaleta, I. (2025). Adverse Events in Hemodialysis Patients With Venous Catheters Locked With 30% Trisodium Citrate Versus Alternative Locking Solutions. Hemodialysis International. Parienti J-J, Deryckère S, Mégarbane B, et al. Quasi-experimental study of sodium citrate locks and the risk of acute hemodialysis catheter infection among critically ill patients. Antimicrob Agents Chemother. 2014;58(10):5666-5672. doi:10.1128/AAC.03079-14 Power A, Duncan N, Singh SK, et al. Sodium citrate versus heparin catheter locks for cuffed central venous catheters: a single center randomized controlled trial. Am J Kidney Dis 2009;53:1034–41.

Source:PMCF_DLOCK_211

The Netherlands 2021A data report is intended to assess safety and performance outcome information from collected data on Medcomp Long-Term Hemodialysis Catheters, Short-Term Hemodialysis Catheters, and 30.0% Duralock-C Locking Solution for use in EU MDR clinical evaluation. These outcome measures include dwell time, reasons for removal, exit site infection rates, catheter related blood stream infection (CRBSI) rates, and catheter associated venous thrombosis (CAVT) rates. Product family identification information was also included in the collected data. The dataset was provided by Marcel C. Weijmer, MD, PhD the head of the Department of Internal Medicine and Nephrology at OLVG located in Amsterdam, Netherlands. The dataset is comprised of consecutive cases from January 2010 to October 2019. At least partial data was collected on 315 catheters that were routinely locked with 30.0% Duralock-C Catheter Lock Solution. 27 of these catheters were long-term (tunneled, cuffed) hemodialysis catheters, and 288 were short-term (nontunneled, uncuffed) hemodialysis catheters. The rate of catheter related blood stream infection was 0.48 per 1,000 catheter days in the long-term hemodialysis catheter cohort, and 0.73 per 1,000 catheter days in the short-term hemodialysis catheter cohort. The report equated catheter associated venous thrombus rates to the number of eurokinase lock incidents found in the database, which allowed for a catheter associated venous rate of 1.79 per 1,000 catheter days in the long-term hemodialysis catheter cohort, and 4.90 per 1,000 catheter days in the short-term hemodialysis catheter cohort. The dataset focused on flow problems, and not the etiology of those problems – which may have arisen from tip malposition, tip migration, catheter kinking, fibrin sheath formation or thrombus formation.

Source:PMCF_DLOCK_214

The Duralock-C EuCliD (European Clinical Patient Surveillance Database) Data Collection report is intended to assess collected performance outcome information and review existing safety information on 4.0% and 30.0% DuraLock-C Catheter Lock Solution for use in EU MDR clinical evaluation. EuCliD is maintained by Fresenius Medical Care. Real-world performance data on the use of DuraLock-C Locking Solution was measured against potential acceptance criteria derived from State of the Art safety and performance outcome measures from published literature. These acceptance criteria were based on non-inferiority to the worst-case margin of the confidence interval of outcome-data from literature, and therefore reflect the lowest level of acceptability. The majority of information was specific to DuraLock-C 30.0% (18,162 catheters in 10,689 patients), but also included significant numbers relating to DuraLock-C 4.0% (217 catheters in 157 patients) and the discontinued DuraLock-C 46.7% (206 catheters in 143 patients). This information was also compared to a large data set relating to the use of non-DuraLock-C catheter lock solution (65,144 catheters in 40,554 patients). Overall, this report summarizes information relating to 9,682,587 catheter days and 3,461,027 catheter locking solution instillations across 25 countries in populations representative of the total population of patients with implanted hemodialysis catheters that would be instilled with catheter lock solution. The rate ratios for both uncensored (0.6) and censored (0.53) adverse events between DuraLock-C and Non-DuraLock-C affirm that DuraLock-C is State of the Art in regard to safety. Across all three DuraLock-C concentrations, two adverse events exceeded the minimum rate found in published literature. “Patient failed to attend” was considered a censored adverse event as it is unrelated to the safety and performance of a device; the rate (2.43 events per 1,000 catheter days) was also below the maximum rate found in published literature (3.72 events per 1,000 catheter days). The rate of “Poor blood flow” (1.58 events per 1,000 catheter days) was also below the maximum rate found in published literature. Overall, flow related complications and catheter associated venous thrombus (CAVT) rates were within State of the Art parameters. The rates of catheter related blood stream infection (CRBSI) and catheter associated venous thrombus (CAVT) were found to be within State of the Art safety and performance outcome measure parameters (reflecting the lowest level of acceptability as defined by the manufacturer) for all three concentrations of DuraLock-C separately and collectively. The rates of CRBSI and CAVT affirm that DuraLock-C is State of the Art in regard to performance.

• Source:DuraLock-C Survey Report

The purpose of the DuraLock-C® Survey Plan was to assure consistency when creating surveys, distribution of the surveys and in analyzing the data collected. The results are reviewed and tabulated to ensure that the product remains safe and effective when used as instructed. The survey was distributed to all customers that ordered DuraLock-C® from 01 July 2017 to 31 July 2018. Medcomp anticipated a minimum 90% positive response rate on safety and efficacy questions based on a minimum of 10% response rate from all surveys sent. The DuraLock-C® Survey was provided electronically to clinicians who use the product worldwide by the product distributors. The survey received responses from 76 clinicians from 24 countries including Australia, Bermuda, Canada, Croatia, Ecuador, Finland, Germany, Greece, Holland, Ireland, Italy, Kuwait, Malaysia, Mexico, Panama, Philippines, Portugal, Saudi Arabia, Singapore, South Africa, Sweden, Switzerland, United Arab Emirates, and United Kingdom. DuraLock-C® Survey Report was finalized on 17 September 2018. Survey responses were stratified by concentration as follows:

Source:PMCF_DLOCK_213

The objective of the study is to test the in-vitro antimicrobial potential of all concentrations of DuraLock-C® Catheter Lock Solution. Medcomp, with assistance from NAMSA, created whitepapers to contextualize and apply a scientific narrative to the results of the Antimicrobial in vitro Study (PMCF_DLOCK_213, NAMSA Project # US033993). “Antimicrobial Activity and Safety of the Following Dialysis Catheter Locking Solutions: 4.0% DuraLock-C®, 30.0% DuraLock-C®, 46.7% DuraLock-C® and Heparin. A Comprehensive Evaluation” concluded that solutions of Trisodium Citrate Dihydrate available as DuraLock-C® is effective at preventing some bacterial formation of biofilm in dialysis catheters. DuraLock-C® solutions of Trisodium Citrate Dihydrate dissolved in water at the concentrations at 4.0%, 30,0% and 46.7% weight to volume were very effective at reduction of microorganisms ability to colonize and form biofilm when tested in direct contact with catheters in this study. This is the first study that reports on the direct ability of Trisodium Citrate Dihydrate to directly affect the viability of microorganisms that have colonized the surface of the catheter. This study further shows that the ability of microorganism to colonize catheters is species and catheter material specific. Solutions of Trisodium Citrate Dihydrate at clinically used concentrations may have limited value against MRSA, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Escherichia coli. Whereas Pseudomonas aeruginosa and Candida albicans viability were highly susceptible to reduction of viability to solutions of Trisodium Citrate Dihydrate.

Source:PMCF_DLOCK_212

The objective of the study is to test the in-vitro antithrombotic potential of all concentrations of DuraLock-C® Catheter Lock Solution. Medcomp, with assistance from NAMSA, created whitepapers to contextualize and apply a scientific narrative to the results of the In vitro Blood Loop Assay (PMCF DLOCK_212, APS Study ID QOI001-HE29). “Evaluation of Dialysis Catheter Locking Solutions Using Multiple Concentrations of DuraLock-C® Compared to Heparin with an Innovative in-vitro Test Method for Antithrombotic Activity.” which uses the findings of the In vitro Blood Loop Assay (APS Study ID QOI001-HE29) concluded that all concentrations of DuraLock-C® performed as anticipated with single phase type of activity. DuraLock-C® was active when compared to controls at all concentrations, with the two highest concentrations performing equally, but better than the lowest. Drugs or compounds with multiphasic responses (like heparin) are much more difficult to predict clinical outcomes. DuraLock-C® is an effective alternative to heparin as a locking solution.

Source:PMCIR-003

Three study sites were instructed to enroll thirty patients and collect specific data. Each site observed the use of one of the three concentrations of Duralock-C®. No randomization was employed. There was a ninety day follow up period with a primary endpoint of catheter related blood stream infection and secondary endpoints including catheter patency and catheter dysfunction. The following recruitment totals were achieved: 4.0% DuraLock-C®: 4 Subjects, 30.0% DuraLock-C®: 2 Subjects. 46.7% DuraLock-C®: 12 Subjects (11 that began treatment). SAEs recorded were catheter dysfunction (1 event in the 4.0% group and 1 event in the 30.0% group), peritoneal carcinosis (1 event in the 4.0% group), and paresthesia (1 event in the 30.0% group). Only paresthesia was determined by the investigator to be related to DuraLock-C. AEs described as possibly related to the device were catheter occlusion (1 event in the 4.0% group) and catheter fibrin sheath formation (1 event in the 30.0% group). Due to the limited availability of data due to missing predefined recruitment targets the results have limited significance in terms of evaluating the safety and performance of DuraLock-C® 4.0%, 30.0%, and 46.7%.

Overall Summary of Clinical Safety and Performance

Duralock-C Catheter Lock solution has been demonstrated to maintain patency of the hemodialysis catheter between treatments, allowing continued use of the catheter. There are no studies that enable a direct comparison of the different strengths of Duralock-C® (either 4.0% or 30.0%). If the device is used as intended by the manufacturer, adverse events including dysgeusia, paresthesia, perioral numbness and hypotension are short-lasting and occur in up to 3.72 events per 1,000 catheter days. Inadvertent over instillation of Duralock-C® 30.0% has been associated with severe cardiac arrhythmias.

On-going or Planned Post-Market Clinical Follow-Up (PMCF)

No emerging risks, complications or unexpected device failures have been detected from PMCF activities.

6. Possible Therapeutic Alternatives

• The following clinical practice guidelines have been used to support the below recommendations for treatments: • KDOQI Clinical Practice Guideline for Vascular Access (KDOQI 2019) • Diagnosis and Treatment of CRBSI: Clinical Guidelines of the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC) and the Spanish Society of Intensive Care Medicine and Coronary Units (SEMICYUC) (Chaves 2018) • Guidelines for the Prevention of Intravascular CRIs (O’Grady 2011)

7. Suggested Profile and Training for Users

For use by a qualified, licensed physician or other qualified health care professional under the direction of a physician.

8. Reference to Any Harmonized Standards and Common Specifications (CS) Applied

Revision History