Portal vein ultrasonography in the early diagnosis of necrotizing enterocolitis

Abstract

The nonoperative diagnosis of necrotizing enterocolitis (NEC) is dependent upon the radiographic finding of pneumatosis intestinalis. A significant number of neonates develop clinical signs compatible with NEC but nondiagnostic radiographs. This can result in delayed, inappropriate, or unnecessary therapy. This paper presents experience with portal vein (PV) ultrasonography in the diagnosis of NEC. Since January 1984, 15 newborns with suspected NEC have undergone PV ultrasonography (mean gestation 33 weeks, mean weight 1,705 g). Each had developed abdominal distention with evidence of sepsis. Stool was positive for occult blood in 11. Abdominal radiographs were interpreted as abnormal but nonspecific in 10 neonates, definite pneumatosis in 3, and normal in 2. No infant had portal vein air on plain abdominal radiograph. Occult PV air was detected by ultrasonography in five infants. These included all infants with obvious pneumatosis, a newborn with a nonspecific radiograph and a neonate with a "normal" x-ray. Of the ten infants without PV air on ultrasound, clinical symptoms resolved without specific therapy in seven. Two infants were proven to have nonenteric sepsis, and the remaining newborn developed intestinal necrosis secondary to aortic thrombus. In the five infants with occult PV air on ultrasound, two subsequently required intestinal resection. The remaining three were treated medically for ten days without sequelae. PV ultrasonography has proven to be a helpful adjunct in the early diagnosis of NEC. This diagnostic maneuver, when applied appropriately, may enable early therapy of the infant with NEC and avoid inappropriate or unnecessary therapy in the suspected case.