Hypoplastic left heart syndrome and the nutmeg lung pattern in utero: a cause and effect relationship or prognostic indicator?

BACKGROUND: Hypoplastic left heart syndrome (HLHS) is the third most common cause of critical congenital heart disease in newborns, and one of the most challenging forms to treat. Secondary pulmonary lymphangiectasia has been recognized in association with HLHS, an appearance described on fetal MRI as the "nutmeg lung." OBJECTIVE: To investigate the association of fetal nutmeg lung with HLHS survival. MATERIALS AND METHODS: A retrospective search of the fetal MRI database was performed. The nutmeg lung pattern was defined as T2 heterogeneous signal with tubular structures radiating peripherally from the hila. Postnatal echocardiograms and charts were reviewed. RESULTS: Forty-four fetal MR studies met inclusion criteria, of which 4 patients (9%) had the nutmeg lung pattern and 3 of whom also had restrictive lesions. Mortality in this nutmeg lung group was 100% by 5 months of age. Of the 40 patients without nutmeg lung, mortality/orthotopic heart transplant (OHT) was 35%. Of these 40 patients without nutmeg lung, 5 had restriction on echo, 3 of whom died/had OHT before 5 months of age (60% of patients with restriction and non-nutmeg lung). There was a significantly higher incidence of restrictive lesions (P = 0.02) and mortality/OHT (P = 0.02) in patients with nutmeg lung compared to those without. CONCLUSION: The nutmeg lung MR appearance in HLHS fetuses is associated with increased mortality/OHT (100% in the first 5 months of life compared to 35% with HLHS alone). Not all patients with restrictive lesions develop nutmeg lung, and outcome is not as poor when restriction is present in isolation. Dedicated evaluation for nutmeg lung pattern on fetal MR studies may be useful to guide prognostication and aid clinicians in counseling parents of fetuses with HLHS.

Prenatal growth characteristics of lymphatic malformations.

PURPOSE: The natural history of prenatally diagnosed lymphatic malformations (LM) remains unknown. The ability to predict growth of a lesion is important to prenatal counseling and any future prenatal intervention. We describe the prenatal growth patterns of LMs as they relate to gestational age, anatomical location, and postnatal management. METHODS: A retrospective review of fetuses prenatally diagnosed with an LM who were followed with serial ultrasounds from 2003 to 2014 was performed with attention to the growth of the lesion as indicated by the lesion volume ratio (LVR). RESULTS: Thirty patients with LM had serial ultrasound measurements between 19 and 39weeks gestation. The LVR increased in 53%, decreased in 23%, and remained stable in 23% of fetuses from the initial to the final ultrasound. Unlike other locations that demonstrated both positive and negative growth profiles, axillary lesions only demonstrated increased growth. Lesions with positive growth increased throughout gestation (peak LVR at 35±3weeks). Twenty-four patients had postnatal interventions, including surgical resection, sclerotherapy, and surgery + sclerotherapy. CONCLUSION: LMs have variable prenatal growth profiles. The majority of lesions, especially axillary LMs, will continue to grow throughout gestation and will not reach a growth plateau until the end of gestation. LEVEL OF EVIDENCE: Level III (Retrospective cohort study).