Chylothorax after pediatric cardiac surgery complicates short-term but not long-term outcomes-a propensity matched analysis

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.

Risk factors and early outcomes of chylothorax following congenital cardiac surgery: A single-center experience

Background

This study aims to investigate the incidence and risk factors for chylothorax and to evaluate the effect of chylothorax on the early postoperative outcomes following congenital cardiac surgery.

Methods

A total of 1,053 patients (606 males, 447 females; median age: 12 months; range, 3 days to 48 years) who underwent surgery for congenital heart disease at our institute between January 2018 and December 2019 were retrospectively analyzed. Patients with chylothorax were identified and the data of this cohort was compared with the entire study population. Following the diagnosis of chylothorax, a standardized management protocol was applied to all patients.

Results

Of 1,053 patients operated, 78 (7.4%) were diagnosed with chylothorax. In the univariate analysis, younger age, peritoneal dialysis, preoperative need for mechanical ventilation, surgical complexity, delayed sternal closure, high vasoactive inotrope score in the first 24 h after operation, residual or additional cardiac lesions which required reoperations were found to be the risk factors for chylothorax (p<0.05). In the multivariate analysis, the correlation persisted with only younger age, infections, and peritoneal dialysis requirement (p<0.05). In the chylothorax group, ventilation times were longer, and re-intubation and infection rates were higher (p<0.05). Although the length of intensive care unit and hospital stay was significantly longer in this patient group, there was no significant association between the development of chylothorax and in-hospital mortality (p>0.05).

Conclusion

Chylothorax following congenital cardiac surgery is a significant problem which prolongs the length of hospital stay and increases the infection rates. Complex cardiac pathologies which require surgery at early ages and re-operations are risk factors for chylothorax. Although there is no consensus on the most optimal therapeutic strategy, standardizing the management protocol may improve the results.

Incidence, Risk Factors and Effective Treatment Strategies for Chylothorax After Pediatric Heart Surgeries: Retrospective Analysis of Large Database in Single Institution

Background

Risk factors for postoperative chylothorax in children who had cardiothoracic procedures are not always clear. Due to complex course in post-operative care, It's always challenging to find the risk factors, and their management.

Objective

The aim of our study was to identify the incidence, risk factors and effective treatment approaches for chylothorax after pediatric heart surgery.

Methods

Children who had the cardiac surgery and subsequently developed chylothorax were included in the study. The ratio of the experimental group to the control group was 1:2. Decannulations of extracorporeal membrane oxygenation (ECMO) were not included in the analysis of patient outcomes. For each patient, we keep track of their age, weight, gender, syndrome, RACH-1 scoring, fluid balance, bypass time, clamp time, redo operations, open or close heart surgeries, and rhythm difficulties. Care logs were kept for every single therapy that was administered. Primary outcome was chylothorax, with secondary outcomes included time in the intensive care unit (ICU), length of hospital stay (LOS), and death.

Results

5210 surgeries were performed in six years. 96 patients developed the chylothorax with incidence of 1.8%. In chylothorax group, mean weight was 6.7 ± 4.2, while mean age was 11.7 ± 15.2. Clamp time was 74.5 ± 53.5 versus 39.9 ± 13.7. Mean bypass time was 128.34(76.25) versus 84.3 ± 25.1 with an odds ratio 1.02 (Z test 0.0001). Six (6.3%) children with chylothorax had redo cardiac surgeries in the same admission (p-value 0.01) while none in other. Five (5.2%) cases got operated by thoracotomy, three from left side. Mean Chest tube duration was 10±7.8 days versus 3.8±2.4 in control group. (p-value 0.02). chylothorax resolved (mean resolving time = 4 days) in 76 (79.2%) children with monogen formula. Two patients receive midodrine with no significant effect. Four children underwent surgical repair for chylothorax.

Conclusion

Bypass time linearly increases incidence of chylothorax. Younger age, low weight, syndromic children, redo operations, non-open-heart surgeries, and arrhythmias also contribute to this. Gender, fluid balance, and RACHS-1 Scoring were not significant. While further research and testing are required for the use of midodrine. However, the low-fat formula of Monogen has proven to be an effective treatment.

Octreotide for Acquired Chylothorax in Pediatric Patients Post-Cardiothoracic Surgery for Congenital Heart Disease: A Systematic Review

Chylothorax is a life-threatening complication post-corrective congenital heart surgery. Octreotide is used for treatment of refractory chylothoraces, with no standardized treatment protocol and a paucity of literature describing its efficacy. Our aim was to provide an update on the safety and efficacy of octreotide for the treatment of refractory chylothoraces in neonatal and pediatric patients' post-corrective congenital heart surgery. We performed a systematic review of PubMed, Medline, CINAHL, and Cochrane Library databases. Only intravenous octreotide treatment was included. A total of 621 patients across 27 studies were included. Studies included were 11 case series, 5 case studies, and 11 retrospective cohort studies. Variation in treatment regimens were reported. Treatment efficacy was reported in 95% (23/27) of studies. Definitions of treatment efficacy were reported in 33% (9/27) of studies. No prospective or randomized control trials were available for inclusion. Octreotide efficacy is widely reported despite a lack of standardization on criteria for treatment initiation or what defines an appropriate response to therapy.Please check and confirm whether the edit made to the article title is in order.Yes.

Development of consensus recommendations for the management of post-operative chylothorax in paediatric CHD

OBJECTIVE

A standardised multi-site approach to manage paediatric post-operative chylothorax does not exist and leads to unnecessary practice variation. The Chylothorax Work Group utilised the Pediatric Critical Care Consortium infrastructure to address this gap.

METHODS

Over 60 multi-disciplinary providers representing 22 centres convened virtually as a quality initiative to develop an algorithm to manage paediatric post-operative chylothorax. Agreement was objectively quantified for each recommendation in the algorithm by utilising an anonymous survey. "Consensus" was defined as ≥ 80% of responses as "agree" or "strongly agree" to a recommendation. In order to determine if the algorithm recommendations would be correctly interpreted in the clinical environment, we developed ex vivo simulations and surveyed patients who developed the algorithm and patients who did not.

RESULTS

The algorithm is intended for all children (<18 years of age) within 30 days of cardiac surgery. It contains rationale for 11 central chylothorax management recommendations; diagnostic criteria and evaluation, trial of fat-modified diet, stratification by volume of daily output, timing of first-line medical therapy for "low" and "high" volume patients, and timing and duration of fat-modified diet. All recommendations achieved "consensus" (agreement >80%) by the workgroup (range 81-100%). Ex vivo simulations demonstrated good understanding by developers (range 94-100%) and non-developers (73%-100%).

CONCLUSIONS

The quality improvement effort represents the first multi-site algorithm for the management of paediatric post-operative chylothorax. The algorithm includes transparent and objective measures of agreement and understanding. Agreement to the algorithm recommendations was >80%, and overall understanding was 94%.

Image-guided chest tube drainage in the management of chylothorax post cardiac surgery in children: a single-center case series

BACKGROUND

In children, chylothorax post cardiac surgery can be difficult to treat, may run a protracted course, and remains a source of morbidity and mortality.

OBJECTIVE

To analyze the experience with percutaneous image-guided chest-tube drainage in the management of post-cardiac-surgery chylothoraces in children.

MATERIALS AND METHODS

We conducted a single-center retrospective case series of 37 post-cardiac-surgery chylothoraces in 34 children (20 boys; 59%), requiring 48 drainage procedures with placement of 53 image-guided chest tubes over the time period 2004 to 2015. We analyzed clinical and procedural details, adverse events and outcomes. Median age was 0.6 years, median weight 7.2 kg.

RESULTS

Attempted treatments of chylothoraces prior to image-guided chest tubes included dietary restrictions (32/37, 86%), octreotide (12/37, 32%), steroids (7/37, 19%) and thoracic duct ligation (5/37, 14%). Image-guided chest tubes (n=43/53, 81%) were single unilateral in 29 children, bilateral in 4 (n=8/53, 15%), and there were two ipsilateral tubes in one (2/53, 4%). Effusions were isolated, walled-off, in 33/53 (62%). In 20/48 procedures (42%) effusions were septated/complex. The mean drainage through image-guided chest tubes was 17.3 mL/kg in the first 24 h, and 13.4 mL/kg/day from diagnosis to chest tube removal; total mean drainage from all chest tubes was 19.6 mL/kg/day. Nine major and 27 minor maintenance procedures were required during 1,207 tube-days (rate: 30 maintenance/1,000 tube-days). Median tube dwell time was 21 days (range 4-57 days). There were eight mild adverse events, three moderate adverse events and no severe adverse events related to image-guided chest tubes. Radiologic resolution was achieved in 26/37 (70%). Twenty-three children (68%) survived to discharge; 11 children (32%) died from underlying cardiac disease.

CONCLUSION

Management of chylothorax post-cardiac-surgery in children is multidisciplinary, requiring concomitant multipronged approaches, often through a protracted course. Multiple image-guided chest tube drainages can help achieve resolution with few complications. Interventional radiology involvement in tube care and maintenance is required. Overall, mortality remains high.

Post-Operative Chylothorax in Children Undergoing Congenital Heart Surgery

Chylothorax is a rare postoperative complication of congenital heart surgery. It has high morbidity with increased hospital stay and cost of treatment. Damage to the thoracic duct, disruption of accessory lymphatic vessels, and increased venous pressure exceeding that in the thoracic duct have been proposed as the possible causes of chylothorax after surgery for congenital heart disease. Prompt diagnose with early initiation of treatment will reduce the duration of drainage. Staged treatment is the general principle in managing this serious complication. Loss of chyle leads to volume, nutritional and electrolyte depletion, immunological deficiencies and hematological complications. Identifying the underlying cause and addressing it is crucial to definitive management.

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

The incidence of chylothorax is reported from 1-9% in pediatric patients undergoing congenital heart surgery. Effective evidenced-based practice is limited for the management of post-operative chylothorax in the pediatric cardiac intensive care unit. The study characterizes the population of pediatric patients with cardiac surgery and chylothorax who eventually require pleurodesis and/or thoracic duct ligation; it also establishes objective data on the impact of various medical interventions. Data were obtained from the Pediatric Health Information System database from 2004-2015. Inclusion criteria for admissions for this study were pediatric admissions, cardiac diagnosis, cardiac surgery, and chylothorax. These data were then divided into two groups: those that did and did not require surgical intervention for chylothorax. Other data points obtained included congenital heart malformation, age, gender, length of stay, billed charges, and inpatient mortality. A total of 3503 pediatric admissions with cardiac surgery and subsequent chylothorax were included. Of these, 236 (9.4%) required surgical intervention for the chylothorax. The following cardiac diagnoses, cardiac surgeries, and comorbidities were associated with increased odds of surgical intervention: d-transposition, arterial switch, mitral valvuloplasty, acute kidney injury, need for dialysis, cardiac arrest, and extracorporeal membrane oxygenation. Statistically significant medical interventions which did have an impact were specific steroids (hydrocortisone, dexamethasone, methylprednisolone) and specific diuretics (furosemide). These were significantly associated with decreased length of stay and costs. Dexamethasone, methylprednisolone, and furosemide were associated with decreased odds for surgical intervention. These analyses offer objective data regarding the effects of interventions for chylothorax in pediatric cardiac surgery admissions. Results from this study seem to indicate that most post-operative chylothoraxes should improve with furosemide, a low-fat diet, and steroids.

Non-surgical Risk Factors for the Development of Chylothorax in Children after Cardiac Surgery-Does Fluid Matter?

We hypothesize that there are post-operative, non-surgical risk factors that could be modified to prevent the occurrence of chylothorax, and we seek to determine those factors. Retrospective chart review of 285 consecutive patients < 18 years who underwent cardiac surgery from 2015 to 2017 at a single institution pediatric intensive care unit. Data was collected on patient demographics, cardiac lesion, surgical and post-operative characteristics. Primary outcome was development of chylothorax. Of 285 patients, median age was 189 days, median weight was 6.6 kg, 48% were female, and 10% had trisomy 21. 3.5% of patients developed upper extremity DVTs, and 8% developed chylothorax. At 24 h following surgery, a majority were in the 0-10% fluid overload category or had a negative fluid balance (63% and 34%, respectively), and a positive fluid balance was rare at 72 h (16%). In univariate analysis, age, weight, bypass time, DVT, arrhythmia, and trisomy 21 were significantly associated with chylothorax and adjusted for in logistic regression. Presence of an upper extremity DVT (OR 49.8, p < 0.001) and trisomy 21 (OR 5.8, p < 0.001) remained associated with chylothorax on regression modeling. The presence of an upper extremity DVT and trisomy 21 were associated with the development of chylothorax. Fluid overload was rare in our population. The presence of positive fluid balance, fluid overload, elevated central venous pressure, and early initiation of fat containing feeds were not associated with chylothorax.

Human Milk Retains Important Immunologic Properties After Defatting

BACKGROUND

In neonatal chylothorax, thoracic lymphatic drainage is ineffective. The resultant effusions often require drainage, leading to a loss of immune components. Affected infants can be managed with formula or defatted human milk feedings low in long-chain triglycerides to decrease lymph production. We hypothesized that there is no significant difference in the immunological profile or antibacterial effect of full-fat and defatted human milk.

METHODS

Milk from lactating mothers was divided into 1 aliquot that was defatted via centrifugation with the full-fat aliquot as control. Macronutrient content was analyzed with mid-infrared spectroscopy. Flow cytometry was used to measure immune cell populations. Lactoferrin, lysozyme, immunoglobulin (Ig)A, and IgG values were determined using enzyme-linked immunosorbent assay. The antibacterial properties were determined by inoculating paired full-fat and defatted milk samples with Escherichia coli or Streptococcus pneumoniae bacteria and performing colony counts.

RESULTS

Compared with full-fat milk, defatted milk demonstrated decreased total energy and fat and increased carbohydrate concentrations. Defatted milk demonstrated a significant decrease in all immune cell populations. There was no difference in IgA, IgG, lysozyme, or lactoferrin concentrations. Both aliquots demonstrated equivalent growth inhibition of E. coli and S. pneumoniae.

CONCLUSIONS

Unexpectedly, defatted human milk contained significantly less leukocytes than full-fat milk. IgA, IgG, lysozyme, and lactoferrin concentrations were preserved. The ability of defatted milk to inhibit bacterial growth was unaffected, suggesting that the antibacterial benefits of human milk remain after the defatting process. Further investigation regarding the clinical effect of leukocyte loss in defatted milk is warranted.

Lymphatic dysfunction in critical illness

PURPOSE OF REVIEW

The essential role of the lymphatic system in fluid homeostasis, nutrient transport, and immune trafficking is well recognized; however, there is limited understanding of the mechanisms that regulate lymphatic function, particularly in the setting of critical illness. The lymphatics likely affect disease severity and progression in every condition, from severe systemic inflammatory states to respiratory failure. Here, we review structural and functional disorders of the lymphatic system, both congenital and acquired, as they relate to care of the pediatric patient in the intensive care setting, including novel areas of research into medical and procedural therapeutic interventions.

RECENT FINDINGS

The mainstay of current therapies for congenital and acquired lymphatic abnormalities has involved nonspecific medical management or surgical procedures to obstruct or divert lymphatic flow. With the development of dynamic contrast-enhanced magnetic resonance lymphangiography, image-directed percutaneous intervention may largely replace surgery. Because of new insights into the mechanisms that regulate lymphatic biology, pharmacologic inhibitors of mTOR and leukotriene B4 signaling are each in Phase II clinical trials to treat abnormal lymphatic structure and function, respectively.

SUMMARY

As our understanding of normal lymphatic biology continues to advance, we will be able to develop novel strategies to support and augment lymphatic function during critical illness and through convalescence.

Causes and manifestations of chylothorax in children in China: Experience from a children's medical center, 2007-2017

IMPORTANCE

Chylothorax is the most common cause of pleural effusion in neonates and relatively rare in children. It can cause significant respiratory morbidity. Many clinical entities may contribute to chylothorax.

OBJECTIVE

To investigate the causes and manifestations of chylothorax in infants and children in China.

METHODS

Case records of 107 cases with chylothorax seen in Beijing Children's Hospital from 2007 to 2017 were retrieved and analyzed; follow-up was carried out by telephone.

RESULTS

Of 107 cases, 58.9% (63/107) were primary chylothorax (PC) and 41.1% (44/107) were secondary chylothorax (SC). Also, 36.4% (39/107) were neonatal chylothorax (NC) and 35.5% (38/107) were postoperative chylothorax. In PC with a verified lymphatic anomaly, there was one case of diffuse pulmonary lymphangiomatosis (DPL) and six cases of generalized lymphatic anomaly (GLA), which accounted for 6.5% (7/107) of cases. In most patients, chylothorax was alleviated by conservative treatment based on total parenteral nutrition (TPN); 13.1% (14/107) of cases needed further surgery. In NC, the median duration of TPN was 9 days, but 10 of 20 cases who improved had recurrence upon re-introduction of a fat-free diet, which was alleviated by further TPN. The duration of hospitalization was (23 ± 14) days for congenital chylothorax. Upon long- term follow-up, except for GLA and DPL, most patients were doing well without recurrence.

INTERPRETATION

NC and postoperative chylothorax are the common subtypes. TPN is effective for most patients. Despite a prolonged and fluctuating clinical course, most patients had a good long-term prognosis.