Comparison of Venous Thrombosis Complications in Midlines Versus Peripherally Inserted Central Catheters: Are Midlines the Safer Option?

Catheter-related (CR) thrombosis is a significant complication of midline catheters (MCs) and peripherally inserted central catheters (PICCs). Limited existing data for MCs suggest a favorable complication profile for MCs. To compare incidence of CR thrombosis between MCs and PICCs and to evaluate the impact of quantity of lumens and catheter diameter on CR thrombosis. This was a retrospective comparison spanning 13 months of MCs and PICCs for symptomatic CR thrombosis at an 1100 bed tertiary care academic medical center. Adult patients who had an MC or a PICC placed by the were included. Data were collected using the electronic medical record. Statistical analysis was performed using SAS software. A total of 2577 catheters were included in the analysis with 1094 MCs and 1483 PICCs. One hundred thirty (11.88%) MCs developed CR thrombosis (deep vein thrombosis [DVT] or superficial venous thrombophlebitis [SVT]) as compared to 112 (6.88%) PICCs (odds ratio [OR]: 1.82; P < .0001). Midline catheters had a 53% greater odds of developing CR DVT than PICCs (7.04% MCs and 4.72% PICCs; OR: 1.53; P = .0126). For CR SVT, MCs have a 2.29-fold greater odds of developing CR SVT than PICCs (4.84% MCs and 2.16% PICCs; OR: 2.29; P = .0002). For MCs and PICCs, the incidence of CR thrombosis was 13.50% for double lumen/5F lines and was 6.92% for single lumen/4F lines (OR: 2.10; P = <.0001). Symptomatic CR thrombosis is a serious, life-threatening complication that occurs more frequently in MCs compared to PICCs. Inserters should consider placement of single lumen catheters with the smallest diameter to reduce this risk when a midline is used.