Primary thromboprophylaxis with heparins for arteriovenous fistula failure in pediatric patients.
BACKGROUND
To reduce the incidence of early arteriovenous fistula failure (AVF) due to thrombosis in pediatric hemodialysis (HD) patients, a primary thromboprophylaxis (PTP) protocol was initiated at author's institution in June 2005. The goal of this study is to report author's experience with this protocol one year later.


RESULTS
19 AVFs (14 patients, Historical group) and 8 AVFs (7 patients, PTP group) were created prior to and after initiation of PTP respectively. PTP consisted of unfractionated heparin (5-10 units/kg/hr) infusion postoperatively, followed by subcutaneous low molecular weigh heparin (LMWH) until AVF was matured. LMWH dosing was 'Prophylactic' (0.5 mg/kg/d, anti-factor Xa levels: peak 0.25-0.5 and trough < 0.3 units/mL) and 'Therapeutic' (1 mg/kg/d, anti-factor Xa level: peak 0.5-1 and trough < 0.5 units/mL) based on thrombosis predisposition. In Historical group, 12 AVFs did not receive thromboprophylaxis (No-treatment group), 5 received 81 mg aspirin/day (Aspirin group), and 2 received LMWH. In No-treatment group 10/12 AVFs failed: 9 thromboses and 1 stenosis. In Aspirin group 1/5 AVFs failed due to thrombosis. In PTP group 1/8 AVFs failed due to stenosis; the first 2 AVFs developed hematoma prompting a reduction in LMWH dose and monitoring trough anti-factor Xa levels, one AVF required thrombectomy after LMWH was transiently held. The incidence of thrombosis was less in PTP group (12.5%) when comparing to No-treatment group (83%) (p < 0.05).


CONCLUSIONS
PTP is a feasible option to prevent early thrombosis at AVF. Close clinical and laboratory monitoring including trough anti-factor Xa levels is required to adjust optimum anticoagulation. Larger studies are needed to clarify safety and efficacy of our PTP protocol.
Sharathkumar
A
A
Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI 48109, USA. aalatkar@umich.edu
Hirschl
R
R
Pipe
S
S
Crandell
C
C
Adams
B
B
Lin
J J
JJ
D000293:Adolescent; D000328:Adult; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D001241:Aspirin / Q000627:therapeutic use; D002648:Child; D002985:Clinical Protocols; D004334:Drug Administration Schedule; D016903:Drug Monitoring; D005240:Feasibility Studies; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D015397:Program Evaluation; D006435:Renal Dialysis; D013927:Thrombosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors; D017211:Treatment Failure; D014654:Vascular Patency / Q000187:drug effects*
D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D006493:Heparin; D001241:Aspirin