A social-media comment raised two questions about ultrasound assessment of an indwelling vascular access device.

When is a sterile probe cover required, and what should an ultrasound assessment consider beyond the visible insertion site?

What the current professional standard says about asepsis

Standard 10.12 of the 2026 NIVAS Standards for Infusion Therapy and Vascular Access states that asepsis must be maintained when an ultrasound probe is used during peripheral and central vascular access.

Its practice guidance is explicit:

“An appropriate sterile single-use ultrasound probe cover and gel must be used during vascular access procedures…”

NIVAS also specifies sterile single-use gel and a sterile probe cover for vein assessment when cannulation is likely within 24 hours, and for assessment before vessel cannulation. After the cover is removed, the probe must be cleaned using a compatible disinfectant product in line with the manufacturer's guidance.

This is the relevant current professional wording. It is stronger and more reliable than attempting to turn a social-media instruction into a universal rule for every possible ultrasound examination.

What Elli and colleagues studied

Elli and colleagues published a 2020 study describing ultrasound-guided tip location for midline catheters. The study compared a group receiving ultrasound-guided tip location with two historical groups that did not.

The technique was reported as feasible in 98.9% of patients in the study group. Catheter-related venous thrombosis occurred in 2.42% of one historical control group, 9% of the other and 2.62% of the ultrasound-guided group.

The authors used cautious language:

“The ideal position of the tip of a midline catheter might be inside the axillary vein…”

This was not a randomised comparison. The control groups were historical, and the authors said it was possible that tip position was associated with the higher thrombosis incidence in one group. The paper supports interest in tip location and ultrasound assessment, but it does not prove that one scanning approach prevents thrombosis in every setting.

What the fibroblastic-sleeve paper reported

Fabiani and colleagues reported a single case involving a 76-year-old woman with a 20 cm polyurethane midline catheter. A surrounding fibroblastic sleeve had been documented during serial ultrasound follow-up.

After catheter removal, a new echogenic mass was observed on the tricuspid valve. Because of the timing and the disappearance of the sleeve from the cannulated vein, the authors attributed the finding to acute embolisation of the sleeve. No respiratory, cardiovascular or septic complication was documented, and the mass had disappeared after 45 days.

This is a case report. It can identify a possible complication and a question for further study, but one case cannot establish incidence, predict which patients are at risk or set a universal monitoring protocol.

A later prospective pilot study by Passaro and colleagues recruited 41 patients with midline catheters. Follow-up ultrasound was available for 27. Ten fibroblastic sleeves and two symptomatic catheter-related thromboses were detected. The sample was small, follow-up was incomplete, and no statistically significant association between tip position and complications was found.

What the HERITAGE study did and did not answer

The 2024 HERITAGE study was a prospective cohort comparison of polyurethane long peripheral catheters and midline catheters. Its primary outcome was catheter failure within 30 days; secondary outcomes included bloodstream infection, thrombosis and fibroblastic sleeve.

Midline catheters were associated with a lower adjusted risk of catheter failure and a longer uncomplicated indwelling time in that cohort. The study also reported higher incidence rates for the secondary outcomes among long peripheral catheters.

The study helps distinguish outcomes associated with two catheter types. It did not test sterile probe covers, did not provide a protocol for assessing a leaking device and should not be used alone to decide what is happening in an individual patient.

Questions for a governed device assessment

Taken together, the sources support a structured set of questions rather than a diagnosis from an image or video:

• Is the ultrasound being used as part of a vascular access procedure or pre-cannulation assessment covered by Standard 10.12?
• Are the probe cover, gel, probe decontamination and aseptic technique consistent with the current standard, manufacturer instructions and local policy?
• What is known about the catheter type, length, insertion date, tip location and intended use?
• Is catheter function altered, including infusion, aspiration, leakage, pain or resistance?
• Does the ultrasound assessment include the relevant catheter pathway and tip rather than only the insertion site?
• Are thrombosis, fibroblastic sleeve, malposition, infiltration, infection or another complication being considered within an appropriate clinical assessment?
• What escalation, further imaging or device-management pathway does local policy require?

These questions do not replace patient assessment, clinical judgement or local governance. Ultrasound findings must be interpreted by an appropriately trained practitioner in the full clinical context.

Related reading: Difficult IV access, VAD selection and escalation and Certificates, competency and employer sign-off.

Sources

National Infusion and Vascular Access Society (NIVAS) (2026). Standards for Infusion Therapy and Vascular Access, first edition. See Standard 10.12, printed page 22, and Standard 21.18, printed pages 51-52. Read the NIVAS standards.

Elli, S. et al. (2020). Ultrasound-guided tip location of midline catheters. Journal of Vascular Access, 21(5), 764-768. DOI: 10.1177/1129729820907250.

Fabiani, A. et al. (2025). The dark side of the fibroblastic sleeve: Case report and literature review. Journal of Vascular Access, 26(6), 2128-2132. DOI: 10.1177/11297298241309164.

Fabiani, A. et al. (2024). The longer the catheter, the lower the risk of complications: Results of the HERITAGE study comparing long peripheral and midline catheters. American Journal of Infection Control, 52(11), 1289-1295. DOI: 10.1016/j.ajic.2024.06.019.

Passaro, G. et al. (2026). Incidence of fibroblastic sleeve in midline catheters: A pilot study in a non-intensive medical department. Journal of Vascular Access, 27(2), 600-606. DOI: 10.1177/11297298251356774.