Medical Interventions for Chylothorax and their Impacts on Need for Surgical Intervention and Admission Characteristics: A Multicenter, Retrospective Insight

Neonatal Chylothorax and Early Fluid Overload After Cardiac Surgery: Retrospective Analysis of the Neonatal and Pediatric Heart and Renal Outcomes Network Registry (2015-2018)

OBJECTIVES

To evaluate the association between postoperative cumulative fluid balance (FB) and development of chylothorax in neonates after cardiac surgery.

DESIGN

Multicenter, retrospective cohort identified within the Neonatal and Pediatric Heart and Renal Outcomes Network (NEPHRON) Registry.

SETTING

Twenty-two hospitals were involved with NEPHRON, from September 2015 to January 2018.

PATIENTS

Neonates (< 30 d old) undergoing index cardiac operation with or without cardiopulmonary bypass (CPB) entered into the NEPHRON Registry. Postoperative chylothorax was defined in the Pediatric Cardiac Critical Care Consortium as lymphatic fluid in the pleural space secondary to a leak from the thoracic duct or its branches.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 2240 NEPHRON patients, 4% ( n = 89) were treated for chylothorax during postoperative day (POD) 2-21. Median (interquartile range [IQR]) time to diagnosis was 8 (IQR 6, 12) days. Of patients treated for chylothorax, 81 of 89 (91%) had CPB and 68 of 89 (76%) had Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery Congenital Heart Surgery 4-5 operations. On bivariate analysis, chylothorax patients had higher POD 1 FB (3.2 vs. 1.1%, p = 0.014), higher cumulative POD 2 FB (1.5 vs. -1.5%, p < 0.001), achieved negative daily FB by POD 1 less often (69% vs. 79%, p = 0.039), and had lower POD 1 urine output (1.9 vs. 3. 2 mL/kg/day, p ≤ 0.001) than those without chylothorax. We failed to identify an association between presence or absence of chylothorax and peak FB (5.2 vs. 4.9%, p = 0.9). Multivariable analysis shows that higher cumulative FB on POD 2 was associated with greater odds (odds ratio [OR], 95% CI) of chylothorax development (OR 1.5 [95% CI, 1.1-2.2]). Further multivariable analysis shows that chylothorax was independently associated with greater odds of longer durations of mechanical ventilation (OR 5.5 [95% CI, 3.7-8.0]), respiratory support (OR 4.3 [95% CI, 2.9-6.2]), use of inotropic support (OR 2.9 [95% CI, 2.0-4.3]), and longer hospital length of stay (OR 3.7 [95% CI, 2.5-5.4]).

CONCLUSIONS

Chylothorax after neonatal cardiac surgery for congenital heart disease (CHD) is independently associated with greater odds of longer duration of cardiorespiratory support and hospitalization. Higher early (POD 2) cumulative FB is associated with greater odds of chylothorax. Contemporary, prospective studies are needed to assess whether early fluid mitigation strategies decrease postoperative chylothorax development.

Chylothorax After Heart Surgery in Children

Chylothorax is a consequence of a thoracic duct injury that can occur during surgical procedures in patients with congenital heart disease. It is associated with high rates of morbimortality and increased use of clinical and hospital resources. The aim of this study was to evaluate the risk factors, distribution, manifestations, complications, and treatments for chylothorax in patients undergoing cardiac surgery in a tertiary pediatric hospital in southern Brazil. This is a retrospective, quantitative study, in which all medical records (n = 166) of patients with chylothorax after pediatric cardiac surgery between January 2014 and December of 2020 and a matched control group (n = 166) were analyzed. Over the study period, there was an increase in incidence of chylothorax from 4.5% in 2014 to 7.6% in 2020, a trend that has been reported in the literature. After multivariate analysis, the following were identified as risk factors for the diagnosis of chylothorax: genetic syndrome (OR 2.298); prolonged cardiopulmonary bypass time (greater than 120 min) (OR 2.410); fluid overload in the immediate postoperative period (OR 1.110); and SIRS (OR 2.527). Mortality was two times greater (p = 0.021) and there was a higher rate (34.4%) of infection (p < 0.001) in patients who developed chylothorax. In addition, a sensitivity analysis was performed comparing patients with low- and high-output chylothorax (> 20 mL/kg), which confirmed unfavorable outcomes for the latter group. Herein, we show that hemodynamic alterations were important factors for diagnosis. Understanding the risk factors, outcomes, and complications helps early identification and enables the reduction of morbidity and mortality.

Management of Congenital and Postoperative Chylothorax: Use of Thoracoscopic Lymphatic Leak Ligations with Intraoperative ICG Lymphangiography

BACKGROUND

Congenital chylothorax (CCT) and postoperative chylothorax (POCT) are rare and difficult to treat. We report our treatment strategy and outcomes for chylothorax, including thoracoscopic surgery with indocyanine-green (ICG) near-infrared fluorescence lymphangiography.

METHODS

A retrospective review of patients with CCT and POCT from 2014 to 2021 was performed. After definitive diagnosis, conservative treatments with octreotide, followed by intravenous steroids as needed, were performed. Patients who were refractory to conservative treatment were transferred to surgical treatment, consisting of thoracoscopic lymphatic leak ligations using ICG intraoperative lymphangiography. The effectiveness of conservative and surgical treatment was then examined.

RESULTS

We included 19 cases of CCT and 31 cases of POCT. The 31 POCT patients included 23 of 84 postoperative patients with congenital diaphragmatic hernia (CDH), 7 of 54 postoperative patients with esophageal atresia (EA), and 1 of 3 postoperative patients with lymphatic malformation. The efficacy of conservative treatment was 12/19 for CCT, 22/23 for CDH, and 4/7 for EA. Surgical intervention was performed in 10 patients, and the rate of resolution of chylothorax within 3 weeks after surgery was 90%.

CONCLUSION

Thoracoscopic lymphatic leak ligations with intraoperative ICG lymphangiography are feasible and useful in patients with chylothorax refractory to conservative treatment.

LEVEL OF EVIDENCE

Level IV.

Prediction Model with External Validation for Early Detection of Postoperative Pediatric Chylothorax

Earlier diagnosis of chylothorax following pediatric cardiac surgery is associated with decreased duration of chylothorax. Pleural fluid testing is used to diagnosis chylothorax which may delay detection in patients who are not enterally fed at time of chylothorax onset. Our aim was to develop and externally validate a prediction model to detect chylothorax earlier than pleural fluid testing in pediatric patients following cardiac surgery. A multivariable logistic regression model was developed to detect chylothorax using a stepwise approach. The model was developed using data from patients < 18 years following cardiac surgery from Primary Children's Hospital, a tertiary-care academic center, between 2017 and 2020. External validation used a contemporary cohort (n = 171) from Lucille Packard Children's Hospital. A total of 763 encounters (735 patients) were analyzed, of which 72 had chylothorax. The final variables selected were chest tube output (CTO) the day after sternal closure (dichotomized at 15.6 mL/kg/day, and as a continuous variable) and delayed sternal closure. The highest odds of chylothorax were associated with CTO on post-sternal closure day 1 > 15.6 mL/kg/day (odds ratio 11.3, 95% CI 6,3, 21.3). The c-statistic for the internal and external validation datasets using the dichotomized CTO variable were 0.78 (95% CI 0.73, 0.82) and 0.84 (95% CI, 0.78, 0.9) and performance improved when using CTO as a continuous variable (OR 0.84, CI: 95% CI 0.80, 0.87). Using the models described, chylothorax after pediatric cardiac surgery may be detected earlier and without reliance on enteral feeds.

Chylothorax in newborns after cardiac surgery: a rare complication?

The aim of this study was to analyze patients diagnosed with chylothorax after congenital heart disease surgery among a cohort of neonatal patients, comparing the evolution, complications, and prognosis after surgery of patients who were and were not diagnosed with chylothorax, and to analyze possible risk factors that may predict the appearance of chylothorax in this population. Retrospective and observational study included all neonates (less than 30 days since birth) who underwent congenital heart disease surgery in a level III neonatal intensive care department. We included infants born between January 2014 and December 2019. We excluded those infants who were born before 34 weeks of gestational age or whose birth weight was less than 1800 g. We also excluded catheter lab procedures and patent ductus arteriosus closure surgeries. Included patients were divided into two groups depending on whether they were diagnosed with chylothorax or not after surgery, and both groups were compared in terms of perinatal-obstetrical information, surgical data, and NICU course after surgery. We included 149 neonates with congenital heart disease surgery. Thirty-one patients (20.8%) developed chylothorax, and in ten patients (32.3%), it was considered large volume chylothorax. Regarding the evolution of these patients, 22 infants responded to general dietetic measures, a catheter procedure was performed in 9, and 5 of them finally required pleurodesis. Cardiopulmonary bypass, median sternotomy, and delayed sternal closure were the surgical variables associated with higher risks of chylothorax. Patients with chylothorax had a longer duration of inotropic support and mechanical ventilation and took longer to reach full enteral feeds. As complications, they had higher rates of cholestasis, catheter-related sepsis, and venous thrombosis. Although there were no differences in neonatal mortality, patients with chylothorax had a higher rate of mortality after the neonatal period. In a multiple linear regression model, thrombosis and cardiopulmonary bypass multiplied by 10.0 and 5.1, respectively, the risk of chylothorax and have an umbilical vein catheter decreases risk.

CONCLUSION

We have found a high incidence of chylothorax after neonatal cardiac surgery, which prolongs the average stay and causes significant morbidity and mortality. We suggested that chylothorax could be an underestimated complication of congenital heart disease surgery during the neonatal period.

WHAT IS KNOWN

• Acquired chylothorax in the neonatal period usually appears as a complication of congenital heart disease surgery, being the incidence quite variable among the different patient series (2.5-16.8%). The appearance of chylothorax as a complication of a cardiac surgery increases both mortality and morbidity in these patients, which makes it a quality improvement target in the postsurgical management of this population.

WHAT IS NEW

•Most of the published studies include pediatric patients of all ages, from newborns to teenagers, and there is a lack of studies focusing on neonatal populations. The main strength of our study is that it reports, to the best of our knowledge, one of the largest series of neonatal patients receiving surgery for congenital heart disease in the first 30 days after birth. We have found a high incidence of chylothorax after cardiac surgery during the neonatal period compared to other studies. We suggested that chylothorax could be an underestimated complication of congenital heart disease surgery during this period of life.

The use of steroids in treating chylothorax following cardiac surgery in children: a unique perspective

BACKGROUND

Chylothorax is the accumulation of chyle fluid in the pleural space. The incidence of chylothorax is quite common post-cardiac surgeries in pediatrics especially in Fontan procedures. Although several treatment lines are known for the management of chylothorax, steroids were scarcely reported as a treatment option. We present a unique case of a 4-year-old child who underwent Fontan procedure and suffered a long-term consequence of chylothorax. The chylothorax only fully resolved after introducing corticosteroids as part of her management.

METHODS

A literature review about management of chylothorax post-cardiac surgery in children using Ovid Medline (19462021), PubMed, and google scholar was performed.

CONCLUSION

Conservative management without additional surgical intervention is adequate in most patients. Additionally, somatostatin can be used with variable success rate. However, a few cases mentioned using steroids in such cases. More research and reporting on the use of steroids in the treatment of chylothorax post-cardiac surgeries in children is needed to prove its effectivity. In this article, we describe a case of chylothorax post-Fontan procedure that supports the use of steroids.