The persistent loop sign in neonatal necrotizing enterocolitis: a new cause

Clinical importance of a fixed bowel loop in the treatment of necrotizing enterocolitis

BACKGROUND

The need for surgical treatment in neonates with necrotizing enterocolitis (NEC) is associated with high mortality. Although pneumoperitoneum and progressive disease are generally accepted indications for surgery, it is unclear whether a fixed bowel loop (FBL) should prompt surgery.

OBJECTIVE

To determine the relationship between an FBL, type of treatment, and death in the management of NEC.

METHODS

Retrospective analysis (January 2000-December 2011) of all neonates with definite NEC in a tertiary neonatal intensive care unit. FBL was defined as a persistent (i.e. >24 h) dilated intestinal segment present on serial abdominal X-rays.

RESULTS

NEC was diagnosed in 141 neonates (median gestational age 30 weeks; median birth weight 1,340 g). An FBL was reported in 38 (27%) patients, of whom 18 were treated surgically. Mortality among FBL patients was independent of the type of treatment (surgical versus conservative): 8/18 and 7/20, respectively (p = 0.55). Of the 103 patients without FBL, 37 (36%) were treated surgically, which is comparable to the FBL group. Again, mortality was not related to the type of treatment (surgical versus conservative): 5/37 and 6/66, respectively (p = 0.49). The presence of an FBL was associated with mortality: more patients with an FBL (15/38, 39%) died than without an FBL (11/103, 11%; odds ratio 5.45, 95% confidence interval 2.21-13.45; p < 0.01).

CONCLUSIONS

In NEC patients, an FBL is associated with increased mortality. On its own it has moderate significance to guide treatment. Nevertheless, because it reflects disease severity, early recognition is important and prompt (surgical) treatment should be considered.

Sonographic and radiographic imaging features of the neonate with necrotizing enterocolitis: correlating findings with outcomes

BACKGROUND

Abdominal radiography is the reference standard in imaging neonates with necrotizing enterocolitis (NEC); however, ultrasound of the abdomen including bowel may be of value in this setting.

OBJECTIVE

To correlate sonographic and radiographic findings with patient outcomes in NEC.

MATERIALS AND METHODS

We reviewed sonographic and radiographic exams, as well as clinical, pathological and laboratory records. Ultrasound images were reviewed for free intraperitoneal gas, peritoneal fluid, pneumatosis intestinalis, portal gas, bowel vascularity, bowel wall thickness and echogenicity, peristalsis and the presence of dilated bowel with anechoic contents. Contemporaneously acquired radiographs were reviewed for intraperitoneal gas, pneumatosis intestinalis, portal gas, the sentinel loop sign and gas pattern. Patients were categorized into two groups based on clinical outcome.

RESULTS

Forty-four neonates receiving 55 sonograms were included. Focal fluid collections, echogenic free fluid, increased bowel wall echogenicity and increased bowel wall thickness were statistically significant in predicting an unfavorable outcome. Other features approached significance in predicting poor outcomes: free peritoneal gas, pneumatosis intestinalis, aperistalsis, bowel wall thinning and absent bowel perfusion. Anechoic free peritoneal fluid predicted a good outcome. The sentinel loop sign on radiographs predicted an unfavorable outcome.

CONCLUSIONS

Abdominal sonography and radiography in patients with NEC can help prognosticate the outcome.

Radiographic predictors of disease severity in neonates and infants with necrotizing enterocolitis

OBJECTIVE

The objective of our study was to validate a radiographic scale, the Duke abdominal assessment scale (DAAS), as a tool for predicting the severity of disease in neonates and infants with suspected necrotizing enterocolitis (NEC).

MATERIALS AND METHODS

Study group patients (n = 43) underwent at least two two-view abdominal radiographic series within 48 hours of surgical intervention for suspected NEC complications. Control group patients (n = 86) were patients with suspected NEC who did not undergo surgery for suspected NEC complications. DAAS scores were assigned by two pediatric radiologists with 20 and 6 years' experience.

RESULTS

The initial radiographs of 26 of 43 (60.5%) patients in the study group showed fixed bowel loops (10/43, 23.3%), highly probable or definite pneumatosis (9/43, 20.9%), or portal venous gas (7/43, 16.3%). These findings had progressed to pneumoperitoneum on the follow-up series in 20 (46.5%) study group patients. Among the control group, three patients (3.5%) had highly probable or definite pneumatosis, and none had fixed bowel loops, portal venous gas, or pneumoperitoneum. Patients with higher DAAS scores were more likely to undergo surgical intervention than patients with lower scores (odds ratio, 1.69; 95% CI, 1.40-2.03). A receiver operating characteristic curve analysis showed good overall performance (c statistic = 0.83) for predicting eventual surgical intervention in the study group with higher DAAS scores.

CONCLUSION

The DAAS provides a standardized 10-point radiographic scale that increases with disease severity when using need for surgical intervention as a surrogate for severe NEC. For every 1-point increase in the DAAS score, patients were statistically significantly more likely to have severe disease as measured by need for surgical intervention.