Ultrasonographic Thrombosis Rates Associated with Midline Catheters in Patients with Advanced Chronic Kidney Disease: A Prospective Cohort Study

Background: Preserving arm veins is important for arteriovenous fistula (AVF) creation in patients with advanced chronic kidney disease (CKD), as mature AVF is the preferred hemodialysis access. Midline catheters introduced into AVF candidate veins may cause thrombosis, hindering AVF formation. This study aims to determine ultrasonographic rates of midline-associated upper extremity deep venous thrombosis (UE-DVT) or superficial venous thrombosis (SVT) in patients with advanced CKD. Methods: We conducted a prospective study involving subjects with advanced CKD, who had a point-of-care ultrasound-guided midline placed in an arm vein. Within 35 days of midline insertion, participants underwent routine bilateral UE venous duplex ultrasound. The primary outcome was a composite occurrence of UE-DVT/SVT ipsilateral to the midline. Comparative analyses were performed based on patient demographics and device-specific variables. Results: 49 subjects with advanced CKD received midlines. The median midline catheter dwell time was <6 days for 15/49 patients (30.6%). The primary outcome occurred in 15/49 patients (30.6%), mostly asymptomatic thrombosis. No significant associations were found between outcomes and patient or device characteristics. Conclusions: Our study identified frequent use of midlines with short dwell times in subjects with advanced CKD which calls into question proper device selection. In this cohort, midline-associated arm clots were frequent.