Duplex ultrasound and clinical outcomes of medical management of pediatric lower extremity arterial thrombosis

Objectives: Natural history and duplex ultrasound (DU) findings of pediatric lower extremity arterial thrombosis (PLEAT) are not well-defined. We describe acute and short-term DU findings of PLEAT to aid duplex interpretation and patient management. Methods: From August 2018 to April 2021 children with suspected PLEAT were identified prospectively. All had DU studies and were divided into group 1 (with DU-confirmed PLEAT) and group 2 (without DU-confirmed PLEAT). Patient demographics and DU findings were compared. Those with PLEAT and follow-up DU studies were also evaluated for recanalization and post recanalization DU findings. Results: We included 76 children (102 limbs) who had suspected PLEAT; 32 in group 1 and 44 group in 2. Fifty-seven percent had congenital heart disease, 26% a history prematurity (87%, 34% group 1; 11%, 14% group 2), with 14% of group 1 premature at PLEAT diagnosis and 68% aged less than 3 years—29 (94%) in group 1 and 23 (52%) in group 2. None had an arterial procedure to restore flow. Limb salvage was 100% with five group 1 mortalities unrelated to PLEAT. In group 1, 12 PLEATs were associated with an arterial line and 15 with cardiac catheterization. Occluded arteries included 7 external iliac, 20 common femoral, and 5 superficial femoral arteries (SFA). Peak systolic velocities (PSVs) distal to occluded segments in group 1 were lower than corresponding group 2 PSVs. SFA 18 ± 21 cm/s vs 84 ± 39 cm/s; popliteal artery (PA) 24 ± 18 cm/s vs 78 ± 38 cm/s; posterior tibial artery (PTA) 10 ± 8 cm/s versus 49 ± 27 cm/s (all P < .001). Twenty-one patients in group 1 had follow-up studies. Twelve (57%) were recanalized: 4 (19%) in less than 1 week and 10 (48%) by 6 months. Eighty-one percent of PLEATs were treated with anticoagulation (AC) and 57% recanalized. Fifty-nine percent of patients on AC recanalized, and 60% not on AC recanalized. Age, primary diagnosis, instrumentation type, and AC were not associated with failure to recanalize. After recanalization, PSVs in the CFA were not different than PSVs found in group 2 in the CFA (109 ± 50 cm/s vs 107 ± 57 cm/s; P = .88), but remained decreased in the SFA, PA, and PTA (SFA 68 ± 32 cm/s vs 83 ± 38 cm/s [P = .04]; PA 33 ± 13 cm/s vs 78 ± 37 [P = .0004]; and PTA 21 ± 8 cm/s vs 43 ± 20 cm/s [P = .0008]). Conclusions: PLEAT occurs in young children, results in low distal PSVs, and often does not recanalize, but does not lead to short-term limb loss or mortality or necessarily require AC for recanalization. Normalization of CFA PSVs indicates recanalization while PSVs in segments distal to the CFA do not seem to return to normal.