An Expanded Post-Thrombosis Sequelae Assessment Scale in Children.

OBJECTIVE: The prevalence of post-thrombosis sequelae (PTS) is increasing in children due to an increase in venous thromboembolic events (VTEs). Pediatric PTS involves extremity and non-extremity manifestations depending on the location of VTEs. Existent PTS assessment scales assess the severity of extremity PTS only. The aim of this study was to develop a clinically significant Expanded PTS Assessment Scale (EPTSAS) which will incorporate both extremity and non-extremity manifestations and provide a framework for interventions.

METHOD: All children with objectively confirmed VTEs that were prospectively followed in the Pediatric Coagulation clinic from 2004 to 2006 were included in the study. The clinical consequences that could be directly attributed to intravenous hypertension due to VTEs were carefully recorded and an EPTSAS was developed. This scale included 4 major (varicosities, ulceration, non-extremity manifestations, radiological findings) and 9 minor criteria (pain, swelling, venous collaterals, limb-length and limb-circumference discrepancies, facial swelling, increase in head circumference, activity limitation, tenderness, skin hyperpigmentation). The interpretation was categorized into 3 grades: clinically non-significant, clinically significant and clinically severe (Table). Three independent investigators classified the patients using EPTSAS, one of whom was a pediatric hematologist whose responses were considered gold standard. The clinical diagnosis of PTS was reinforced by an observed response to treatment and decrease in PTS score on follow up visits.

RESULTS: Fifty children were eligible for assessment. Median age at diagnosis of PTS: 4.6 years (90 days to 22 years). Median follow up: 1 year (180 days to 10 years). Median interval between diagnosis of VTE and development of PTS:180 days (90 to 3 years). Anatomical locations of VTEs were as follows: lower extremity,23; upper extremity,12; intrathoracic,4; intra-abdominal,3; head and neck,8 (neck:3, sinovenous thrombosis:5); multiple locations,5. Frequently observed symptoms were: collaterals 20/50(40%), swelling 13/50(26%), pain 7/50(14%) and activity limitation 10/50(20%). Six(12%) children developed non-extremity manifestations as a consequence of regional thrombosis: portal hypertension,3; chylothorax,1, communicating hydrocephalus, 1; loss of kidney,1. Twenty-seven (54%) children received a score ≥1 on either a major or minor criteria. Based on EPTSAS aggregate scores, PTS were classified as: clinically non-significant:8/27(30%); clinically significant:6/27(22%), clinically severe:13/27(48%). Three of 6 with non-extremity PTS were missed by existing PTS scales. The positive predictive value, negative predicitve value, sensitivity and specifity of EPTSAS at 1 year after initial assessment was 75%(15/20), 100%(30/30),100%(15/15) and 86%(30/35) respectivley. Inter-observer agreement was good, 78%. Intra-observer agreement was very good, 90%.

CONCLUSIONS: This study shows that EPTSAS allows the evaluation of PTS to better cover the full scope of venous thrombotic complications in children. The validity of this EPTSAS will be evaluated prospectively with a larger sample size.