90 - Congenital Chylothorax: A Case for Consensus Management Guidelines

Poster Number: 90
Publication Number: 90.438

Rachel Alade, UPMC Childrens Hospital of Pittsburgh, Pittsburgh, PA, United States; Andrew McCormick, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, United States; Michael D. Fox, NemoursAlfred I. duPont Hospital for Children, Wilmington, DE, United States

Background: Congenital chylothorax (CC) is a rare neonatal disorder associated with significant morbidity and mortality (Rocha et al.l 2021). Advancements in genetic testing have improved our understanding of CC as a clinical manifestation of a heterogenous group of disorders (Attar & Donn, 2017). Treatment of CC has traditionally focused on symptomatic management; the accessibility of full exome sequencing and advanced imaging has facilitated the implementation of gene-targeted interventions and intravascular approaches to treatment. Early utilization of these therapies is critical in preventing the sequelae of CC.

Objective: To develop an algorithm for the management and the diagnostic work-up for newborns with CC in order to guide targeted interventions.

Design/Methods: We conducted a literature review of 83 articles focused on CC between 2011-2021. These articles primarily consisted of case reports of experimental, diagnostic, and therapeutic interventions, but we found a dearth of consensus guidelines for rapid evaluation and management of CC. We subsequently performed a descriptive case series of newborns with confirmed chylous effusions treated at UPMC Children’s Hospital of Pittsburgh and Nemours Children’s Hospital, Delaware in 2021. Each subjects’ presenting symptoms, diagnostic imaging, trialed interventions, and outcomes were recorded.

Results: Eight eligible infants were identified (Table 1). Genetic testing was conducted on 7 of 8 infants. CC associated mutations included one recessive PIEZO1 loss-of-function mutation, two subjects with RAS-opathy mutations positive for Noonan Syndrome, one Wolf-Hirschhorn Syndrome, three patients with whole exomes without vascular anomaly associated defects, and one subject who did not undergo genetic testing. Four patients underwent MR lymphangiograms, three underwent MRI’s of the chest, abdomen, and pelvis, and one was unable to undergo any imaging. Most patients received multimodal treatment. Six patients received treatment with octreotide, seven were treated with Sirolimus, two were treated with Trametinib, 1 was treated with a defatted diet alone, and 1 had embolization. Six patients responded to treatment, and three expired. Based on these subjects, we developed an algorithm to guide the
work-up and management of CC (Figure 1).Conclusion(s): Given the importance of gene-based therapies in CC, early genetic and radiographic evaluation is vital in optimizing patient outcomes. The algorithm we created provides much needed guidance for clinicians caring for children with CC and contributes to the standardization of care for patients with vascular malformations.
Approach to Management and Diagnostic Work-Up of Congenital Chylothorax
Case Series of Newborns with Congenital Chylothorax