Sonographic evaluation of neonates with early-stage necrotizing enterocolitis

Abstract

Background: Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in neonatal intensive care units. Ultrasonographic findings in early-stage NEC have not been described. Objective: To assess the diagnostic value of ultrasonography for the diagnosis and monitoring of patients with NEC. Materials and methods: We evaluated the sonographic findings of early stages of NEC in 40 neonates who were clinically diagnosed with NEC when they were 2–28 days old. Their average gestational age was 32 weeks, and their mean weight was 1,850 g. All of the patients showed signs of bowel distention on abdominal radiography, with no evidence of pneumatosis intestinalis. We performed bowel sonography in all patients (n = 40), as well as in ten healthy neonates who served as a control group. The studies were conducted with a 10-MHz linear transducer from February 2003 to January 2004. We evaluated the echogenicity of the bowel wall, involved region, ascites, and portal venous gas at both initial and follow-up examinations. We divided the patients into two groups according to the bowel wall echogenicity pattern, group I with echogenic dots in the bowel wall and group II with dense granular echogenicities in the bowel wall. In order to identify any correlations between the ultrasonography and clinical findings, we evaluated the duration of parenteral feeding (NPO) in each group and compared two groups by means of a statistical analysis (Mann–Whitney test). Results: All of the neonates in the control group (n = 10) presented normal bowel wall echogenicity; the patients with NEC presented echogenic dots in 16 patients (40%) and dense granular echogenicities in 24 patients (60%). Portal venous gas was absent in all patients. On the follow-up examinations, the echogenicity of the bowel wall and ascites decreased in 37 patients (93%). The duration of NPO was 11.1 ± 6.6 days in group I and 16.5 ± 7.2 days in group II (P < 0.05). Conclusion: Echogenic dots or dense granular echogenicities in the bowel wall can be seen in patients with early-stage NEC. Bowel sonography can be helpful for the early diagnosis and monitoring of patients with NEC.