Evaluation of portal venous gas detected by ultrasound examination for diagnosis of NEC
Abstract
Background: Early diagnosis of necrotizing enterocolitis (NEC) is difficult but essential for timely therapy. The diagnostic hallmarks and specific radiologic signs for NEC are pneumatosis intestinalis (PI) and portal venous gas (PVG), but PVG in abdominal ultrasound (PVG-US) has been proposed as an effective tool in the diagnosis of NEC as well.
Objective: We prospectively assessed the value of PVG-US for the diagnosis of NEC.
Methods: We screened 352 neonates for PVG-US (n = 796 routine examinations) and performed 48 additional screenings in 34/352 neonates with suspected (I°, n = 28) or definite NEC (≥ II°, n = 20) as defined by Walsh and Kliegman. Sensitivity and specificity of PVG-US for detection of NEC were computed by using NEC ≥ II° as the reference standard.
Results: PVG-US was only present in cases of suspected or definite NEC. We observed PVG-US in 4/28 NEC I° and in 9/20 NEC ≥ II° episodes corresponding to a 86% specificity and a 45% sensitivity for diagnosis of NEC ≥ II°. However, 7/20 patients with NEC ≥ II° showed intraoperative findings other than NEC and another 3/20 infants presented with radiologically unspecific intestinal dilatation. None of these 10 infants had PVG-US detectable. Thus, with application of specific radiologic signs the sensitivity of PVG-US for diagnosis of NEC ≥ II° increased to 90%.
Conclusion: Screening for PVG-US is a useful, easily and quickly performed bedside test with a high specifity for NEC. Moreover, our results question the value of the Walsh criteria in the diagnosis of NEC.
