Which causes more thrombosis, Peripherally Inserted Central Catheter (PICC) or midline catheter?

PICC Lines Cause More Thrombosis Than Midline Catheters

Based on the most recent high-quality evidence, PICCs are associated with a significantly higher risk of deep venous thrombosis compared to midline catheters, though midlines carry greater risk of superficial venous thrombophlebitis. 1

Key Evidence on Thrombosis Risk

Overall Thrombosis Rates

• A 2023 systematic review and meta-analysis found that midline catheters were associated with lower rates of catheter-related bloodstream infection (CRBSI) compared to PICCs (OR 0.24,95% CI 0.15-0.38), though no significant difference was found for deep venous thrombosis or pulmonary embolism when evaluated per catheter. 1

• However, subgroup analysis revealed that midlines had higher rates of superficial venous thrombosis (OR 2.30,95% CI 1.48-3.57) compared to PICCs. 1

Comparative Thrombosis Data

• A 2019 single-center study of 2,577 catheters found that midlines had 53% greater odds of developing catheter-related DVT than PICCs (7.04% vs 4.72%; OR 1.53, p=0.0126). 2

• For superficial venous thrombophlebitis specifically, midlines had 2.29-fold greater odds than PICCs (4.84% vs 2.16%; OR 2.29, p=0.0002). 2

• Overall catheter-related thrombosis (DVT or SVT combined) occurred in 11.88% of midlines versus 6.88% of PICCs (OR 1.82, p<0.0001). 2

Guideline Perspectives

• ESPEN guidelines note that PICCs have a "main limitation" of "shorter longevity, due to a higher risk of thrombosis" compared to other central access devices. 3

• The 2017 ACR Appropriateness Criteria specifically states that "PICCs have been associated with a higher incidence of thrombosis in patients with hematological and nonhematological malignancies." 3

• The 2023 ESPEN HPN guideline acknowledges that "PICCs seem to be associated with a lower risk of catheter-related bloodstream infection (CRBSI) and a possible higher risk of catheter-related venous thrombosis." 3

Clinical Decision Algorithm

For Short-Term Use (≤14 days)

• Midline catheters are preferred for peripherally compatible infusates when duration is 6-14 days, as they have lower infection risk despite higher superficial thrombosis risk. 3

• For irritants or vesicants requiring central access, PICCs are appropriate despite thrombosis risk, as midlines cannot provide central venous access. 3

For Medium-Term Use (15-30 days)

• PICCs are preferred over midlines beyond 15 days due to midline failure rates, though thrombosis risk remains a consideration. 3

• Consider single-lumen, smaller diameter catheters (4F) to reduce thrombosis risk, as double-lumen/5F lines have 2.10-fold higher thrombosis rates (13.50% vs 6.92%, p<0.0001). 2

For Long-Term Use (>30 days)

• Tunneled catheters or implanted ports are preferred over PICCs for durations exceeding 30 days, as they have lower thrombosis and infection rates. 3

• For home parenteral nutrition expected to last >6 months, tunneled catheters are strongly preferred over PICCs. 3

Risk Mitigation Strategies

Catheter Selection

• Use the smallest caliber catheter compatible with therapy needs—avoid PICCs >4F to reduce thrombosis risk. 3

• Choose single-lumen over multi-lumen catheters when possible, as this reduces thrombosis risk by approximately 50%. 2

• Utilize ultrasound guidance for placement to limit vascular damage. 3

Catheter Positioning

• Position the catheter tip at the superior vena cava-right atrium junction to minimize thrombosis risk. 3

• Prefer right-sided insertion over left-sided to reduce thrombosis risk. 3

Important Caveats

Type of Thrombosis Matters

• While midlines have higher overall thrombosis rates in some studies, the thrombosis is predominantly superficial (SVT) rather than deep (DVT). 1, 2

• Superficial thrombophlebitis, though uncomfortable, carries less morbidity than deep venous thrombosis and pulmonary embolism risk associated with central catheters. 3

Study Quality Considerations

• The 2023 meta-analysis included only 1 RCT among 20 studies, with most evidence from observational studies, limiting certainty of conclusions. 1

• A 2022 study found no significant differences in DVT rates between PICCs (4%) and midlines (3%, p=0.12), suggesting equipoise in some populations. 4

Patient-Specific Factors

• In patients with previous thrombosis history, both device types carry increased risk, and alternative access should be considered. 3

• Prophylactic low molecular weight heparin is effective only in high-risk patients and is not routinely recommended for all catheter placements. 3