The guidewire exchange using the Modified Seldinger technique: A safe alternative for PICC and midlines

Background

Since its initial application in medicine, using a guidewire to insert vascular devices into vascular structures has become a cornerstone of vascular access techniques. ¹ The idea that a guidewire can facilitate new catheter insertions and allow for the exchange of an inserted catheter was established shortly thereafter. As early as 1965, Dotter described its functionality as a “rail” for inserting dilators of varying diameters. ² Today, the guidewire exchange technique (GWE) is employed routinely during interventional radiology procedures and cardiac catheterization. Since the 1970s, GWE has gained increasing popularity as a strategy to minimize venipunctures and their associated risks related to them. ³ However, the possibility of an elevated risk of infection has consistently hindered its use. ⁴ For example, dialysis venous catheters can be replaced using GWE when there is no suspicion of infection ⁵ or serve as a “rescue” strategy when a new insertion site is not available. ⁶ Regarding other catheters, current guidelines restrict their use to situations where a new procedure proves challenging and discourage their application in the presence of confirmed or suspected infections linked to vascular access. ⁶

Although this technique is widely employed, its application for peripherally inserted central catheters (PICCs) and midlines (MCs) remains inadequately documented in the literature. This text outlines the GWE procedure using a Modified Seldinger technique (MST) kit, which comprises a small needle (not intended for use in GWE), a 0.018″ 50 cm long nitinol guidewire with a shaping ribbon tip (a soft tip that can be straight or angled), ⁷ an obturator, and a peelable micro-introducer (Figure 1). MST kits of various lengths and diameters are available. They are usually inserted into each PICC or Midline catheter set. This paper aims to describe a safe guidewire exchange technique in PICC and MC using an MST kit (GWE-MST). Furthermore, our case series seeks to summarize previously published studies related to the infection and thrombosis risks of GWE-MST to enhance the evidence supporting its safety profile.

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Figure 1.

Components of a Modified Seldinger technique kit (from top to bottom): 21G needle, 0.018″ nitinol guidewire, 50 cm long (note the shaping ribbon tip—red arrow), Obturator, Peelable micro-introducer.

Indications and contraindications

Technique

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Figure 2.

The catheter was cut and clamped before insertion of the guidewire.

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Figure 3.

Advance the guidewire into the vessel while gradually withdrawing the catheter; please note the portion of guidewire exposed (red arrow).

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Figure 4.

Guidewire scrubbing with Clorexidine 2%.

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Figure 5.

Safety maneuver to confirm intravascular positioning of the micro-introducer. The guidewire is securely held (red arrow), and blood return is observed upon obturator retraction (yellow arrow).

Results

A retrospective analysis was conducted using the vascular access database of the Vascular Access Team at Luigi Sacco Hospital (Milan, Italy). This case series included 52 patients who underwent GWE-MST between December 2019 and November 2024.

Among the cohort, 37 patients (71.2%) were inpatients, including seven (13.5%) in surgical departments. The median age was 71 years (interquartile range: 60.75–82), and 24 patients (46.2%) were male. Thirty-nine patients (75%) underwent catheter replacement with a PICC, while 13 (25%) received an MC. The median catheter dwell time was 11 (IQR 5–23) days in the first placement and 16 (IQR 3–36) days for the replaced catheter through GWE-MST.

Most devices (52.4%) had been initially placed in the brachial vein. At the same time, the remaining catheters were positioned in either the basilic or the superficial femoral vein, with an exit site in the mid-thigh (28.8% for both). In one case, the substituted catheter was tunneled; for this reason, a longer peel-away (10 cm) was used.

No CRBSI or central line-associated bloodstream infection (CLABSI) was recorded after the GWE-MST. The procedure was performed in two low-suspicion CLABSI cases, and the catheter was used only after the tip culture of the removed one was negative.

The available data indicate that only one patient experienced catheter-related thrombosis in a PICC inserted in the superficial femoral vein with an exit site at mid-thigh bedridden for orthopedic surgery, and no other significant complications were reported following GWE-MST. Additionally, one patient developed a minor post-procedural hematoma, which was considered clinically negligible.

Further details on patient characteristics and catheter specifications are provided in the Supplemental File, SFT1.

Discussion

In this paper, the authors describe the GWE technique for PICC and MC insertion using an MST kit. Although widely utilized, to the authors’ knowledge, this is the first publication to describe the method comprehensively. Based on the observed results, there does not appear to be an association between the use of GWE-MST and an increase in major complications such as CRT or CRBSI. However, the small sample size requires further studies to confirm these hypotheses.

Surprisingly, although widely used, there is little evidence in the literature regarding this topic.

On the one hand, the observed data seem to coincide with the study’s results by Brugioni et al., ⁸ who did not observe complications in a population of 27 patients in whom a long peripheral catheter had been positioned and subsequently replaced with a PICC. On the other hand, the results of this study are opposite to those reported by McCoy et al. ⁹ and Chopra et al. ¹⁰

The first, a retrospective analysis of 61 patients in neonatal intensive care units, observed a 25-fold increase in the risk of CLABSI using GWE. Similar results were observed in the study by Gnannt et al. on 55 pediatric patients with rupture of the external catheter tract. ¹¹

These differences could be attributed to variations in insertion techniques and catheter materials. For instance, McCoy’s study focuses on epicutaneo-cava catheters inserted using the over-the-needle technique, which differs from the one considered in this paper. Similarly, in Gnannt’s study, the presence of catheters made from various materials and cuffed devices may have influenced the outcomes.

Moreover, the catheter replacement technique also presents some differences. In this study, GWE was performed using the over-the-wire technique; no information was given about the type of Seldinger technique (direct or modified); this factor could make it more challenging to maintain sterility during manipulation, potentially impacting procedural outcomes. Also, the skin disinfection was performed with chlorhexidine at 2% or with betadine, and it is recognized that the last one is correlated with an increased risk of CRBSI. ¹²

In 2021, a study by Pearse et al. underscores the clinical and economic implications of unnecessary catheter removal. Among over 230 venous access devices removed due to suspected CLABSI, only 10 were ultimately associated with confirmed bacteremia. This discrepancy resulted in a differential rate of 22.4 suspected versus confirmed CLABSI cases per 1000 catheter days, leading to an estimated unnecessary expenditure of AUD$67.087. ¹³ These findings lead the authors to consider this technique when there is a low suspicion of CRBSI in patients with challenging venous access (i.e. extensive burns, morbid obesity, or severe coagulopathy) according to guidelines of the Spanish Society of Infectious Diseases and Clinical Microbiology and the Spanish Society of Intensive and Critical Care Medicine and Coronary Units. ⁶ In this case, a culture of the catheter tip is mandatory, and the new catheter, inserted over a guidewire, should be replaced via a new direct venipuncture if the catheter tip culture is positive.

Colaneri et al. reported in a recent paper on two GWE-MST’s experience with low suspicion infection. ¹⁴ Unlike the traditional Seldinger technique, where both the catheter in situ and the new catheter share the same guidewire, potentially facilitating cross-contamination, the MST approach may reduce or even eliminate this risk. In the MST technique, while the existing catheter directly interacts with the guidewire, the newly inserted catheter interfaces primarily with the micro-introducer. Since the internal walls of the micro-introducer have no contact with the guidewire, which slides through the kit’s obturator, the potential for contamination may be significantly reduced.

Although current guidelines advise against catheter exchange in cases of suspected catheter-related infection, ⁶ this remains a topic of considerable debate within the scientific community, as available evidence presents conflicting findings.^15,16 The ability to safely perform GWE-MST in this scenario could provide clinicians with an alternative strategy to mitigate de novo catheter insertion complications. Moreover, it could serve as a practical solution for patients with suspected catheter-related infection, in whom premature catheter removal, often driven by urgency or inadequate adherence to international recommendations, remains a prevalent issue. ¹⁴

While this hypothesis is compelling, it remains speculative, and well-designed clinical studies are necessary to evaluate the feasibility and safety of this approach rigorously.

Chopra et al.’s study ¹⁰ (retrospectively analyzed 589 patients from various clinical settings on which GWE was performed) found that 3.6% developed venous thromboembolism. Multivariate Cox regression demonstrates a significant association between exchange over the guidewire and an increased risk of venous thromboembolism (p = 0.003, HR 1.98 (1.37–2.85)). However, a similar significant correlation was associated with using multi-lumen catheters or those with larger diameters.

Given the well-documented evidence in the literature indicating that larger PICCs are more prone to CRT, ¹⁷ it is plausible that the observed findings are influenced by confounding factors, particularly an unfavorable CVR.

Calculating the internal diameter of the vessel intended for catheter placement is essential to ensure optimal catheter selection. This step is particularly critical when upgrading to a larger device, as it allows for verification of compliance with an appropriate CVR to minimize the risk of complications. ¹⁸ Chopra et al.’s paper does not provide information about ultrasound evaluation before GWE. ¹⁰

This study noted only one case of CRT, which reflects 1.9% of the overall CRT rate, consistent with existing literature findings. ¹⁸ Moreover, this patient was at the highest risk for thrombosis if evaluated with a Caprini risk score (age over 75 years, Elective major lower extremity surgery, leg fracture, Current central venous access, Patient confined to bed >72 h).

The GWE-MST can be employed for tunneled devices; however, careful consideration is required depending on the tunneling method used.

When the extended subcutaneous route (ESR), also called pseudo-tunneling, ¹⁹ has been applied, the procedure is generally uncomplicated, as the subcutaneous tract corresponds to the length of the micro-introducer. Conversely, additional precautions are necessary if a blunt tunneler has been utilized, as the tunnel length may exceed that of the standard micro-introducer. ¹⁹

To ensure procedural success, it is imperative to determine the original tunnel length, either by consulting existing clinical records or performing an ultrasound assessment. If required, a micro-introducer longer than the standard size provided in MST kits should be used. Furthermore, intravascular positioning of the micro-introducer tip must always be confirmed by removing the obturator while maintaining the guidewire and verifying blood return (step 16). This is crucial to ensuring proper catheter placement and minimizing the risk of complications.

GWE-MST may also be considered for replacing vascular access devices inserted in emergencies. This approach can be advantageous when implementing a combined technique that integrates GWE-MST with tunneling. For example, it may facilitate replacing a catheter inserted initially in the common femoral vein at the groin with a tunneled device with an exit site at the mid-thigh.

It is essential to underscore that this procedure should be performed within the first 48 h following catheter placement to reduce the risk of infection and other procedural complications. ²⁰

No clinically significant bleeding complications were reported in the case series presented, suggesting that the GWE-MST technique may represent a feasible option for patients with coagulation disorders. While further dedicated studies are warranted to establish its safety and efficacy in this specific population, it is reasonable to consider catheter replacement as a preferred approach over de novo insertion, given that the latter necessitates a new venipuncture, which may increase the risk of hemorrhagic complications.

Only open-ended catheters were used, which limits the opportunity to evaluate GWE-MST in catheters with a distal valve that could, in theory, hamper the passage of the guidewire.

Conclusions

Based on our data and recognizing limitations (e.g. small sample size), along with literature evidence, we can conclude that the GWE-MST demonstrated safety. This suggests the potential for a broader study involving a larger population to establish clear and definite guidelines regarding the circumstances under which this procedure can be safely executed.

Supplemental Material