Midline catheter as effective device in healthy allogeneic donors and patients without an adequate peripheral venous access for HPC collection by apheresis: Preliminary experience at IEO

Beyond traditional venous access: Midline catheter use in pediatric apheresis

The objective of this study was to assess the use of midline catheters as venous access for apheresis procedures in pediatric patients. A retrospective analysis of medical records was conducted from September 2019 to June 2022 to evaluate the safety and efficacy of midline catheters for therapeutic pediatric apheresis. During the study period, a total of 121 procedures were inserted in 22 unique patients. The age of the subjects ranged from 2.7 to 21 years. The blood flow rates achieved with midline catheters met or exceeded the recommended rates for apheresis in children (40 mL/min), by the Wilcoxon signed-rank test (p < 0.0001). There was one episode of catheter-related thrombosis, but no cases of bloodstream infection or catheter dislodgement were reported. In conclusion, this study supports the use of midline catheters as a safe and effective alternative for venous access during therapeutic and donor apheresis procedures in pediatric patients.

Stem Cells Collection and Mobilization in Adult Autologous/Allogeneic Transplantation: Critical Points and Future Challenges

Achieving successful hematopoietic stem cell transplantation (HSCT) relies on two fundamental pillars: effective mobilization and efficient collection through apheresis to attain the optimal graft dose. These cornerstones pave the way for enhanced patient outcomes. The primary challenges encountered by the clinical unit and collection facility within a transplant program encompass augmenting mobilization efficiency to optimize the harvest of target cell populations, implementing robust monitoring and predictive strategies for mobilization, streamlining the apheresis procedure to minimize collection duration while ensuring adequate yield, prioritizing patient comfort by reducing the overall collection time, guaranteeing the quality and purity of stem cell products to optimize graft function and transplant success, and facilitating seamless coordination between diverse entities involved in the HSCT process. In this review, we aim to address key questions and provide insights into the critical aspects of mobilizing and collecting hematopoietic stem cells for transplantation purposes.

Peripheral blood stem cell collection: Are midline catheters a viable alternative to central venous catheters?

BACKGROUND

Vascular access is a rate-limiting step for peripheral blood stem cell collection. In the absence of readily accessible superficial veins, placement of tunnelled or non-tunnelled central venous catheters (CVCs) is common. These invasive access routes create medical risks for patients and are associated with logistical challenges, thus prompting a search for alternatives. One such option is the off-label use of midline catheters.

STUDY DESIGN AND METHODS

We carried out a literature search for published experience with the use of midline catheters for peripheral blood stem cell collection. Data extracted included whether collections were allogeneic or autologous, donor sex, age and weight, inlet flow rate, total blood volumes (TBV) processed, collection duration, number of collections per donor, and achievement of collection targets.

RESULTS

The search produced three reports (one in abstract form) comprising 19 patients and 26 collection events. Donor sex and status were provided for 18 patients; 10 were female, 8 were male, 12 were allogeneic, and 6 autologous. Median (range) for: donor age was 28 (12-59); donor body weight (kg) was 77.5 (45.4-113.4); inlet flow rate (in mL/min) was 66 (28-80); TBV processed (in mL) was 15,880 (6178-21,871); collection duration (in hours) was 5.0 (3.2-7.0); and CD34 × 106/kg collection yield was 5.9 (3.6-23.0). Target CD34 yields were achieved in 14/19 (74%) of donors with 7/19 (37%) requiring two collections days.

DISCUSSION

Peripheral blood stem cell collection does appear to be viable via midline-based catheter access, particularly for allogeneic donors and shorter collection courses. Development of institution-specific guidelines and care pathways are recommended.

Midline catheters for extracorporeal photopheresis in hematological patients

INTRODUCTION

Peripheral venous access for extracorporeal photopheresis (ECP) may be difficult in graft versus host disease (GVHD) patients, because of previous intravenous therapies and multiple peripheral cannulations; in this population of patients, ultrasound guided midline catheters may be an alternative option to central venous access.

METHODS

In this single-center, prospective preliminary study, we enrolled all consecutive patients with a diagnosis of GVHD and candidate to ECP, over a period of 10 months. We used inserted power injectable, non-valved, polyurethane, 20-25 cm single lumen midline catheters (MC).

RESULTS

Sixty-nine ECP procedures were carried out in six patients, using single-lumen MCs for outflow (5Fr in 74% and 4Fr in 26% of cases). For inflow, we used 5Fr or 4Fr MCs, or central venous access devices previously placed for other clinical reasons. There were no catheter-related complications during the entire period of ECP treatment. Mean outflow was significantly higher for 5Fr than for 4Fr MCs (35.8 ± 7.3 vs 29.2 ± 7.8 ml/min; p = 0.0008) and the procedure time was significantly shorter (92.9 ± 9.2 vs 108 ± 13.2 min; p < 0.0001).

CONCLUSION

In GVHD patients, ECP can be performed efficiently and safely using single lumen polyurethane power injectable MCs. The best results are obtained with 5Fr rather than with 4Fr catheters. This strategy of venous access should be implemented in DIVA patients requiring ECP treatments, and probably also in other types of apheresis.

Midline Catheters: Could They Replace a Central Vascular Access Device?

In the past 30 years, midline catheter use has grown rapidly. For several reasons, many providers and facilities are attempting to reduce the number of central venous catheters and subsequent central line-associated bloodstream infections (CLABSIs) by using midline catheters. Vessel preservation requires attention to all vascular access device (VAD)-associated complications and not only central line bloodstream infection. There is still much confusion about the appropriate tip location and the characteristics of fluids and medications that can safely be infused through a midline catheter residing in a peripheral vein. The Infusion Therapy Standards of Practice (the Standards) focuses on assessment of characteristics of infusion therapies that must be considered for VAD selection as an evidence-based list of fluids and medications for infusion through peripheral veins has yet to be established. This review of midline catheter studies evaluates the evidence regarding the substitution of a midline catheter for a central venous catheter. Many issues need to be addressed, such as studies that include an outcome list that mixes defined clinical complications (eg, thrombosis) with signs and symptoms of complications (eg, leaking). Another issue is basing a major change of clinical practice on retrospective chart reviews. Although a midline catheter may be appropriate for some patients, additional studies of a higher level of evidence are needed before this major practice change should occur.

Novel use of a midline catheter for therapeutic and donor apheresis in children and adults

BACKGROUND

Apheresis procedures require adequate vascular access to achieve optimal inlet flow rates. While central lines provide such access, their placement and use are associated with risks; some of these risks are minimized if peripheral intravenous access can be established. However, peripheral intravenous access is associated with challenges in the pediatric setting. Research indicates that midline catheters reduce the use of CVADs and their associated risks. The use of midline catheters for apheresis has been reported recently in adults, but no studies have been published on their use in children. Thus, the purpose of this study was to evaluate the use of midline catheters for apheresis in the pediatric setting.

METHODS

A retrospective observational study was conducted to evaluate the safety and efficacy of midline catheters in subjects who underwent apheresis at a pediatric hospital from April 2018 to August 2020. Demographic data, clinical data (diagnosis, procedure, catheter size, body mass), and outcome data (inlet flow rate, total blood volume [TBV] processed, procedure time, and cell counts) were collected.

RESULTS

Eighteen subjects received a total of 100 midline catheters for 73 apheresis procedures. Inlet flow rates ranged from 45 to 80 mL/min, TBV ranged from 2872 to 20 000 mL, and procedure time ranged from 1.25 to 7 hours. Inlet flow rates met or exceeded the recommended inlet flow rates for apheresis in children and adults (P < .0001). No adverse events occurred.

CONCLUSION

Midline catheters provide safe and effective vascular access for apheresis. Future research should include younger patients with lower body mass.