Liver abscess in neonates

Abstract

Introduction: Liver abscesses are rare in neonates with the majority resulting from an ascending infection via the umbilical and portal veins, haematogenous spread, or via the biliary tree, or via direct contiguous spread from neighbouring structures. They may present in unusual ways often presenting with ongoing sepsis and resulting in diagnostic difficulties. We present the clinical and radiological findings on six neonates with hepatic abscesses and underline the association with misplacement of umbilical line, association with hypertonic glucose infusions and TPN.

Methods: A retrospective chart review made of six patients diagnosed with hepatic abscesses between 2000 and 2006. Methods included clinical and radiological review as well as evaluation of potential risk factors.

Results: Five of the six patients with neonatal liver abscess were of low birth weight and low gestational age (range 30-34 weeks), but one was post mature (42 weeks). Sex distribution was equal and two were HIV exposed (mother positive), two HIV negative with two having an unknown HIV status. Clinical signs included raised infective markers (CRP) (6) and non-specific signs of septicaemia (4), but a tender hepatomegaly (1) and abdominal distension with ileus (1) were also noted. Five were right-sided abscesses (2 associated with malposition of umbilical line) and one central in position. Predisposing factors included association with a misplaced umbilical line with high concentration glucose infusions (2) and tuberculosis was later diagnosed in one. Infective markers (CRP) remained high with positive blood cultures persisting in all. Causative organisms included Klebsiella (3) Staphylococcus (3) [one a multi-resistant staphylococcus (MRSA)], Gonococcus (1) and Enterobacter (1). Abdominal X-ray demonstrated a mal-positioned umbilical line in three patients (50%). Ultrasound (US) proved a reliable method of diagnosis although some difficulty was encountered in interpreting resolving abscesses and trans-diaphragmatic spread occurred in one. Three patients (50%) responded to antibiotic therapy alone, but interventional drainage was required in the remainder. Needle aspiration was successful in two of these, but one further patient had a radiologically placed pigtail drainage, but later required open drainage. This patient then developed trans-diaphragmatic spread and empyema requiring thoracoscopic decortication.

Conclusion: Neonatal hepatic abscesses are rare but should enter the differential diagnosis of a neonate with ongoing sepsis. This study serves to draw attention to their association with misplaced central (umbilical) catheters. Failure to respond to antibiotic therapy necessitates interventional drainage.