LAUSR

Severe veno-occlusive disease (VOD), or sinusoidal obstruction syndrome (SOS), is a significant cause of postHSCT morbidity and mortality. This complication typically develops predominantly in the first 21 days of HSCT, although pediatric onset may be later in 15–20% [1]. Severe VOD/SOS leads to multi-organ failure (MOF), in which mortality exceeds 80% [2, 3]. The incidence of SOS/VOD in children after HSCT varies widely in reports, ranging from 8 to 60% [1, 4, 5]. The diagnosis is typically made by clinical observations as outlined by the Baltimore or the modified Seattle criteria [6, 7]. The Baltimore criteria are based on the presence of hyperbilirubinemia (>2 mg/dL) and 2 of the following: weight gain >5% from baseline, hepatomegaly, or ascites. The modified Seattle criteria require any 2 of the following: hyperbilirubinemia (2 mg/dL), ascites and/or unexplained weight gain of >2% from baseline or hepatomegaly and right upper quadrant pain. Reversal of portal flow by ultrasound is commonly noted, although this is not pathognomonic nor included in the Baltimore or modified Seattle criteria. The treatment of SOS/VOD in children is highly variable, as noted in a recent survey [8]. Until recently, management included supportive care only, as thrombotic agents were not effective and also increased the risk of bleeding. Defibrotide, an anti-thrombotic with antiinflammatory and anti-ischemic properties, is the only definitive therapy available for severe VOD/SOS. In international multicenter phase II and III clinical trials, treatment of severe VOD/SOS with defibrotide resulted in complete remission in 36–56% [9, 10]. However, outcomes in this patient population still remain suboptimal, with mortality occurring primarily from respiratory and/or renal failure and MOF. Ascites develops in 20–80% of children with SOS/VOD and may be contribute to multi-organ failure (MOF) with respiratory compromise from abdominal competition and renal dysfunction from vascular compression [8]. Diuretics may be of limited benefit due to intra-vascular dehydration. Drainage of ascites can improve respiratory excursion and prevent renal injury from intra-abdominal hypertension and impaired renal perfusion, but is not standard of care [8]. A recent retrospective study by Madenci et al [4]. reviewed the safety of pleural and peritoneal drain placement in pediatric HSCT patients with severe SOS/VOD. However, there was limited information about its utility when used with defibrotide in preventing MOF. We describe clinical features and outcomes in pediatric patients who developed SOS/VOD and received PD, in comparison to those who did not receive PD. All patients were treated with defibrotide.