Resolution of calcific brown fat necrosis associated with prostaglandin therapy for cyanotic congenital heart disease in neonates: report of two cases

Brown fat necrosis with calcifications in the newborn: Risk factors, radiographic findings, and clinical course

Objective:

To describe the radiographic appearance of subclinical calcified brown fat necrosis and the associated clinical and laboratory findings.

Materials and Methods:

Picture Archiving and Communications Sytem (PACS) was searched using keywords “soft tissue calcification” and “chest.” The clinical record was searched for prior cardiac surgery, bypass, Extracorporeal Membrane Oxygentation (ECMO) and prostaglandin use. Age when calcifications were first detected, location, resolution, and associated laboratory abnormalities were recorded.

Results:

Nine patients were identified. None had skin lesions. All patients had congenital heart disease and had experienced cardiac/respiratory arrest and/or severe hypotension 1–6 weeks before soft tissue calcifications occurred. Calcifications resolved by 9 weeks to 5 months in 3 patients. The remaining were either deceased or lacked follow-up imaging. Renal ultrasound was performed in all but 1 patient. Nephrocalcinosis was only seen in 1 patient.

Conclusion:

Brown fat necrosis is subclinical, diagnosed on plain film, and likely self-limited. It occurs in term and preterm infants who have undergone significant systemic stress and carries a poor prognosis.

Prostaglandin E1 for maintaining ductal patency in neonates with ductal-dependent cardiac lesions

BACKGROUND

Prostaglandin E1 (PGE1) is used to keep the ductus arteriosus patent and can be life-saving in neonates with ductal-dependent cardiac lesions. PGE1 is used to promote mixing of pulmonary and systemic blood flow or improve pulmonary or systemic circulations, prior to balloon atrial septostomy or surgery. PGE1 therapy may cause several short-term and long-term adverse effects. The efficacy and safety of PGE1 in neonates with ductal-dependent cardiac lesions has not been systematically reviewed.

OBJECTIVES

To determine the efficacy and safety of both short-term (< 120 hours) and long-term (≥120 hours) PGE1 therapy in maintaining patency of the ductus arteriosus and decreasing mortality in ductal-dependent cardiac lesions.

SEARCH METHODS

We searched the literature in October 2017, using the search strategy recommended by Cochrane Neonatal. We searched electronic databases (CENTRAL (in the Cochrane Library), MEDLINE, CINAHL, Embase); abstracts of the Pediatric Academic Societies; websites for registered trials at www.clinicaltrials.gov and www.controlled-trials.com; and in the reference list of identified articles.

SELECTION CRITERIA

Randomized or quasi-randomized trials using PGE1 at any dose or duration to maintain ductal patency in term or late preterm (≥ 34 weeks' gestation) infants with ductal-dependent cardiac lesions and which reported effectiveness and safety in the short term or long term.

DATA COLLECTION AND ANALYSIS

We followed the standard Cochrane methods for conducting a systematic review. Two review authors (SA and MP) independently assessed the titles and abstracts of studies identified by the search strategy to determine eligibility for inclusion. We obtained the full-text version if eligibility could not be done reliably by title and abstract. We resolved any differences by discussion. We designed electronic forms for trial inclusion/exclusion, data extraction, and for requesting additional published information from authors of the original reports.

MAIN RESULTS

Our search did not identify any completed or ongoing trials that met our inclusion criteria.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomized controlled trials to determine the safety and efficacy of PGE1 in neonates with ductal-dependent cardiac lesions. Evidence from observational trials have informed clinical practice on the use of PGE, which is now considered the standard of care for ductal-dependent cardiac lesions. It is unlikely that randomized controlled studies will be performed for this indication but comparative efficacy of newer formulations of PGE1, different doses of PGE1 and studies comparing PGE with PDA stents or other measures to keep the ductus open may be ethical and necessary.

Brown fat distribution in the chest wall of infants-normal appearance, distribution and evolution on CT scans of the chest

BACKGROUND

While reviewing chest CT scans of infants, we repeatedly observed hyperdense enhancing tissue in the chest wall that is not well described in radiology literature.

OBJECTIVE

This study was undertaken to describe the imaging features of this tissue in chest walls of infants.

MATERIALS AND METHODS

CT scans of the chest conducted on all infants between April 2008 and October 2009 were retrospectively reviewed. CT studies with any deviation from normal radiation or contrast dose or those with chest wall anatomical distortion were excluded.

RESULTS

One hundred eighty-eight infants were scanned, with 202 MDCTs, of which 180 (89.1%) received contrast agent. Fifty-four of 180 (30%) cases revealed focal areas of hyperdensity in various locations. All positive cases ranged between 2 days and 9 months of age. The areas of distribution of hyperdensity had excellent correlation with known areas of brown fat in the chest wall, known from nuclear medicine studies, and hence we concluded these to represent the same.

CONCLUSION

Brown fat in the chest wall can be seen as enhancing tissue on contrast CT scans done on infants. This is a normal morphological component with the brown fat converting to normal fat. It is important to recognize it in the chest wall of infants to avoid misinterpretation.