Postoperative chylothorax development is associated with increased incidence and risk profile for central venous thromboses

Chylothorax in Infants and Children After Congenital Heart Surgery: Approach and Review

Chylothorax in infants after surgery for congenital heart disease is associated with significant morbidity and mortality. Numerous management modalities applied alone or in various combinations have been utilized but definitive guidelines have not yet been established. We present two infants who developed refractory chylothorax after congenital heart surgery. We also reviewed evidence for the use of available treatment modalities. In our experience, the use of lymphangiography followed by pleurodesis by povidone-iodine was safe and our impression was that it may have played a decisive role in controlling the lymph leak.

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 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.

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%.

Effect of Minocycline Pleurodesis in Infants With Refractory Chylothorax After Palliative Surgery for Complex Congenital Heart Disease

Chylothorax is a critical complication after surgery for congenital heart disease, which markedly compromises the postoperative course with increased mortality. As the cardiovascular load additively causes stagnation of the thoracic duct, chylothorax after palliative cardiac surgery can be highly refractory to the therapies. Here we report a case of two patients with refractory chylothorax attributed to hemodynamic load which was successfully treated with minocycline pleurodesis. In combination with congenital heart disease, extremely low birth weight coupled with prematurity in case 1 and venous obstruction with excessive volume load due to additional aortopulmonary shunt in case 2 additively increased resistance to the therapies, including fasting with total parenteral nutrition (TPN), XIII factor supplementation, octreotide infusion, as well as the use of steroids. As pleural effusion was sustained at more than 50 ml/kg/day, the condition of both patients deteriorated severely; pleurodesis using minocycline was urgently introduced. Pleural effusion declined at every session and both cases were in remission in a few sessions without unfavorable acute reaction. No symptoms suspecting chronic adverse effects were observed during follow-up, including respiratory dysfunction, pulmonary hypertension, tooth staining, or abnormal bone mineralization. Although the application of minocycline for children should be minimized, minocycline pleurodesis can be an option for patients with refractory and life-threatening chylothorax.

Post-operative Chylothorax in Patients with Repaired Transposition of the Great Arteries

Patients with dextro-transposition of the great arteries (d-TGA) require surgical repair as neonates. These patients are at risk for post-operative chylothorax. We sought to describe the presentation, imaging, and outcomes after intervention for patients with d-TGA with post-operative chylothorax. A retrospective chart review was performed in patients with repaired d-TGA who were referred from 1/1/2013 to 4/1/2020 for evaluation of chylothorax. Patient history, lymphatic imaging, and interventional data were collected. Impact of intervention on lymphatic drainage was evaluated with a student's t-test. Eight patients met inclusion criteria for this study. Five patients had a history of central venous thrombus leading to thoracic duct outlet occlusion. Five patients underwent intervention, two were managed conservatively, and one was not a candidate for intervention. Chylothorax resolved in six patients. There was a significant difference in output from 7 days prior to first intervention (114 mL/kg/day) compared to 28 days following final intervention (27 mL/kg/day, p = 0.034). There were no procedural complications. Chylothorax in patients with repaired transposition of the great arteries is often amenable to intervention. Early surveillance and management of central venous thrombosis may reduce the burden of lymphatic disease in these patients.

A systematic review of the evidence supporting post-operative antithrombotic use following cardiopulmonary bypass in children with CHD

OBJECTIVES

To determine the optimal antithrombotic agent choice, timing of initiation, dosing and duration of therapy for paediatric patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

We used PubMed and EMBASE to systematically review the existing literature of clinical trials involving antithrombotics following cardiac surgery from 2000 to 2020 in children 0-18 years. Studies were assessed by two reviewers to ensure they met eligibility criteria.

RESULTS

We identified 10 studies in 1929 children across three medications classes: vitamin K antagonists, cyclooxygenase inhibitors and indirect thrombin inhibitors. Four studies were retrospective, five were prospective observational cohorts (one of which used historical controls) and one was a prospective, randomised, placebo-controlled, double-blind trial. All included were single-centre studies. Eight studies used surrogate biomarkers and two used clinical endpoints as the primary endpoint. There was substantive variability in response to antithrombotics in the immediate post-operative period. Studies of warfarin and aspirin showed that laboratory monitoring levels were frequently out of therapeutic range (variably defined), and findings were mixed on the association of these derangements with bleeding or thrombotic events. Heparin was found to be safe at low doses, but breakthrough thromboembolic events were common.

CONCLUSION

There are few paediatric prospective randomised clinical trials evaluating antithrombotic therapeutics post-cardiac surgery; most studies have been observational and seldom employed clinical endpoints. Standardised, validated endpoints and pragmatic trial designs may allow investigators to determine the optimal drug, timing of initiation, dosing and duration to improve outcomes by limiting post-operative morbidity and mortality related to bleeding or thrombotic events.

Percutaneous Venous Reconstruction for Central Thrombosis-Associated Chylothorax: A Safe and Efficacious Option

Central thrombosis–associated chylothorax is underrecognized in children and frequently refractory to conservative management. Central venous catheterizations are the predominate cause. We present 3 cases highlighting endovascular techniques used to treat persistent chylous effusions. (Level of Difficulty: Advanced.)

Chylothorax in the neonate-A stepwise approach algorithm

BACKGROUND

Chylothorax in neonates results from leakage of lymph from thoracic lymphatic ducts and is mainly congenital or posttraumatic. The clinical course of the effusion is heterogeneous, and consensus on treatment, timing, and modalities of measures has not yet been established. This review aims to present, along with levels of evidence and recommendation grades, all current therapeutic possibilities for the treatment of chylothorax in neonates.

METHODS

An extensive search of publications between 1970 and 2020 was performed in the PubMed, Cochrane Database of Systematic Reviews, and UpToDate databases. A stepwise approach algorithm was proposed for both congenital and traumatic conditions to guide the clinician in a rational and systematic way for approaching the treatment of neonates with chylothorax.

DISCUSSION AND CONCLUSION

The treatment strategy for neonatal chylothorax generally involves supportive care and includes drainage and procedures to reduce chyle flow. A stepwise approach starting with the least invasive method is advocated. Progression in the invasiveness of treatment options is determined by the response to previous treatments. A practical stepwise approach algorithm is proposed for both, congenital and traumatic chylothoraces.

Diagnosis and Management of Lymphatic Disorders in Congenital Heart Disease

Purpose of Review

Lymphatic disorders have received an increasing amount of attention over the last decade. Sparked primarily by improved imaging modalities and the dawn of lymphatic interventions, understanding, diagnostics, and treatment of lymphatic complications have undergone considerable improvements. Thus, the current review aims to summarize understanding, diagnostics, and treatment of lymphatic complications in individuals with congenital heart disease.

Recent Findings

The altered hemodynamics of individuals with congenital heart disease has been found to profoundly affect morphology and function of the lymphatic system, rendering this population especially prone to the development of lymphatic complications such as chylous and serous effusions, protein-losing enteropathy and plastic bronchitis.

Summary

Although improved, a full understanding of the pathophysiology and targeted treatment for lymphatic complications is still wanting. Future research into pharmacological improvement of lymphatic function and continued implementation of lymphatic imaging and interventions may improve knowledge, treatment options, and outcome for affected individuals.

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.

Lymphovenous Anastomosis for the Treatment of Chylothorax in Infants: A Novel Microsurgical Approach to a Devastating Problem

With the expanding horizon of microsurgical techniques, novel treatment strategies for lymphatic abnormalities are increasingly reported. Described in this article is the first reported use of lymphovenous anastomosis surgery to manage recalcitrant chylothoraces in infants. Chylothorax is an increasingly common postoperative complication after pediatric cardiac surgery, with a reported incidence of up to 9.2 percent in infants. Although conservative nutritional therapy has a reported 70 percent success rate in this patient population, failed conservative management leading to persistent chylothorax is associated with a significant risk of multisystem complications and mortality. Once conservative medical strategies are deemed unsuccessful, surgical or radiologic interventions, such as percutaneous thoracic duct embolization or ligation, are often attempted. However, these procedures lack high-level evidence in the infant population and remain a challenge, given the small size of the lymphatic vessels. As such, we report our experience with performing lymphovenous anastomoses in two infants who had developed refractory chylothoraces secondary to thoracic duct injury following cardiac surgery for congenital cardiac anomalies. In addition, this article reviews the relevant pathophysiology of chylothoraces, current treatment algorithm following failed conservative management, and potential role of the microsurgeon in the multidisciplinary management of this life-threatening problem. As part of the evolving microsurgery frontier, physiologic operations, such as lymphovenous anastomosis, may have a considerable role in the management of refractory pediatric chylothoraces. In our experience, lymphovenous anastomosis can restore normal lymphatic circulation within 1 to 2 weeks, liberate patients from mechanical ventilation, and enable expeditious return to enteral feeding.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Predictive Factors for Central Line-Associated Bloodstream Infections in Pediatric Cardiac Surgery Patients With Chylothorax

OBJECTIVES

To assess the prevalence of central line-associated bloodstream infections in pediatric patients with and without chylothorax after cardiac surgery and identify risk factors that predict those patients at highest risk for developing a central line-associated bloodstream infection.

DESIGN

Retrospective single-center cohort study.

SETTING

A PICU located within a tertiary-care academic pediatric hospital.

PATIENTS

All pediatric patients admitted to the PICU after cardiac surgery between 2008 and 2014.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified 1,191 pediatric cardiac surgery patients in the study time frame, of which 66 (5.5%) had chylothorax. Patients with chylothorax were more likely to have a central line-associated bloodstream infection (23% vs 3.8%; p < 0.001). Patients with both chylothorax and central line-associated bloodstream infection had longer durations of central venous catheter, higher Risk Adjustment Congenital Heart Surgery score, longer PICU stay, and higher mortality compared with patients with chylothorax who did not have a central line-associated bloodstream infection. Multivariable analysis identified higher Risk Adjustment Congenital Heart Surgery score, longer duration of central venous catheter, and higher chest tube output at 24 hours after initiating treatment for chylothorax to be predictive of increased central line-associated bloodstream infection risk in patients with chylothorax.

CONCLUSIONS

The prevalence of central line-associated bloodstream infection is higher in pediatric patients with chylothorax after heart surgery. In patients with chylothorax, complexity of surgery, central venous catheter duration, and chest tube output are associated with increased risk for developing a central line-associated bloodstream infection. Using this knowledge will allow us to identify patients at increased risk for central line-associated bloodstream infections and to focus extra prevention efforts on them.

Nutrition Considerations in the Pediatric Cardiac Intensive Care Unit Patient

Adequate caloric intake plays a vital role in the course of illness and the recovery of critically ill patients. Nutritional status and nutrient delivery during critical illness have been linked to clinical outcomes such as mortality, incidence of infection, and length of stay. However, feeding practices with critically ill pediatric patients after cardiac surgery are variable. The Pediatric Cardiac Intensive Care Society sought to provide an expert review on provision of nutrition to pediatric cardiac intensive care patients, including caloric requirements, practical considerations for providing nutrition, safety of enteral nutrition in controversial populations, feeding considerations with chylothorax, and the benefits of feeding beyond nutrition. This article addresses these areas of concern and controversy.

Chylothorax as a Risk Factor for Thrombosis in Adults: A Proof-of-Concept Study

BACKGROUND

Postoperative chylothorax in children is associated with an increased risk of vascular thrombosis, hypothesized to be from loss of antithrombin into chylous fluid resulting in a hypercoagulable state. In adults, an increased thrombotic risk with chylothorax has not been described. Adults undergoing Ivor-Lewis esophagogastrectomy have two strong thrombotic risk factors-active malignancy and postoperative state-allowing for relative homogeneity in baseline thrombotic risk; therefore, we studied the association of chylothorax with thrombosis in this population.

METHODS

We performed a single-center retrospective cohort study at a tertiary care academic center. Patients included adults undergoing Ivor-Lewis esophagogastrectomy between January 1, 2006, and December 31, 2012. We collected demographics, pleural fluid characteristics, and relevant imaging within 30 days after the operation. Using nominal logistic regression, we studied the effects of chylothorax, age, sex, body mass index, American Society of Anesthesiologists Physical Status Classification, operative duration, and hospital length of stay on the incidence of postoperative thrombosis.

RESULTS

We identified 608 patients who underwent Ivor-Lewis esophagogastrectomy. Of these, 524 (86.2%) had no pleural fluid analysis, 48 (7.9%) had nonchylous effusions, and 36 (5.9%) had chylothoraces, with incident acute vascular thrombosis within 30 days postoperatively occurring in 22 of 524 (4.2%), 2 of 48 (4.2%), and 8 of 36 (22.2%), respectively (p = 0.001). In multivariate analyses, after adjusting for the above factors, chylothorax was associated with significantly higher odds of any vascular thrombosis (odds ratio, 5.46; p = 0.0013) and deep venous thrombosis/pulmonary embolism (odds ratio, 6.76; p = 0.0016).

CONCLUSIONS

Chylothorax is associated with a significantly higher incidence of vascular thrombosis in adults undergoing Ivor-Lewis esophagogastrectomy. Vascular thrombosis was associated with a significantly higher 90-day mortality rate.

Clinical epidemiology and centre variation in chylothorax rates after cardiac surgery in children: a report from the Pediatric Cardiac Critical Care Consortium

Introduction Chylothorax after paediatric cardiac surgery incurs significant morbidity; however, a detailed understanding that does not rely on single-centre or administrative data is lacking. We described the present clinical epidemiology of postoperative chylothorax and evaluated variation in rates among centres with a multicentre cohort of patients treated in cardiac ICU.

METHODS

This was a retrospective cohort study using prospectively collected clinical data from the Pediatric Cardiac Critical Care Consortium registry. All postoperative paediatric cardiac surgical patients admitted from October, 2013 to September, 2015 were included. Risk factors for chylothorax and association with outcomes were evaluated using multivariable logistic or linear regression models, as appropriate, accounting for within-centre clustering using generalised estimating equations.

RESULTS

A total of 4864 surgical hospitalisations from 15 centres were included. Chylothorax occurred in 3.8% (n=185) of hospitalisations. Case-mix-adjusted chylothorax rates varied from 1.5 to 7.6% and were not associated with centre volume. Independent risk factors for chylothorax included age <1 year, non-Caucasian race, single-ventricle physiology, extracardiac anomalies, longer cardiopulmonary bypass time, and thrombosis associated with an upper-extremity central venous line (all p<0.05). Chylothorax was associated with significantly longer duration of postoperative mechanical ventilation, cardiac ICU and hospital length of stay, and higher in-hospital mortality (all p<0.001).

CONCLUSIONS

Chylothorax after cardiac surgery in children is associated with significant morbidity and mortality. A five-fold variation in chylothorax rates was observed across centres. Future investigations should identify centres most adept at preventing and managing chylothorax and disseminate best practices.

Treatment of chylothorax developed after congenital heart disease surgery: a case report

Chylothorax is defined as the accumulation of lymphatic fluid or chyle in the pleural space. Chylothorax treatment is composed of conservative; pleural drainage, termination of enteral feeding, total parenteral nutrition and supplementation with medium- chain triglycerides and surgical therapies; ductus thoracicus ligation, pleuroperitoneal shunts or pleuredesis. Nowadays, for cases among which conservative therapies fail, treatment with octreotide has been reported to be beneficial with promising results. A neonate who developed chylothorax after surgery performed for congenital heart disease was treated successfully with octreotide.

Postoperative Acute Pulmonary Embolism Following Pulmonary Resections

Postoperative acute pulmonary embolism after pulmonary resections is highly fatal complication. Many literatures have documented cancer to be the highest risk factor for acute pulmonary embolism after pulmonary resections. Early diagnosis of acute pulmonary embolism is highly recommended and computed tomographic pulmonary angiography is the gold standard in diagnosis of acute pulmonary embolism. Anticoagulants and thrombolytic therapy have shown a great success in treatment of acute pulmonary embolism. Surgical therapies (embolectomy and inferior vena cava filter replacement) proved to be lifesaving but many literatures favored medical therapy as the first choice. Prophylaxis pre and post operation is highly recommended, because there were statistical significant results in different studies which supported the use of prophylaxis in prevention of acute pulmonary embolism. Having reviewed satisfactory number of literatures, it is suggested that thoroughly preoperative assessment of patient conditions, determining their risk factors complicating to pulmonary embolism and the use of appropriate prophylaxis measures are the key options to the successful minimization or eradication of acute pulmonary embolism after lung resections.

Balloon Angioplasty for the Treatment of Left Innominate Vein Obstruction Related Chylothorax after Congenital Heart Surgery

OBJECTIVE

Chylothorax complicates the postoperative course of patients after congenital heart surgery. Innominate vein thrombosis and stenosis have been associated with postoperative chylothorax. Revascularization and angioplasty can be accomplished using transcatheter techniques. We report our experience with this procedure for the management of postoperative chylothorax.

DESIGN

This is a retrospective case series of patients who underwent catheter revascularization and/or angioplasty of the innominate vein following cardiac surgery at our institution from January 1, 2008 through April 9, 2014.

SETTING

The cardiovascular intensive care unit and cardiac catheterization laboratory at the University of Alabama at Birmingham and Benjamin Russell Hospital for Children in Birmingham, Alabama were used as settings for the study.

PATIENTS

Out of 112 patients with postoperative chylothorax, 7 (6.3%) underwent transcatheter dilation of the innominate vein for occlusion/stenosis. The median age of the cohort was 1 month (15 days-6 years); median weight was 3 kg (2.7-22.2). Diagnosis was made a median 8 days (2-20) and persisted for a median of 24 days (9-44). Most patients failed medical management (low fat diet, nothing by mouth, and/or octreotide).

RESULTS

Cardiac catheterization occurred at a median 9 days (2-29) after chylothorax diagnosis. Median chest tube output on the day prior to procedure was 63 (12-149) cc/kg/day and decreased to 23 (0-64) cc/kg/day 2 days postprocedure (P = .01). Effusions resolved in a median of 5 days (1-16). There were no clinical complications postcatheterization. All patients who have undergone repeat angiography have maintained patency of the innominate vein. There was no mortality. Complications from chylothorax included prolong hospitalization, hyponatremia, hypoproteinemia, coagulopathy, lymphopenia, and infection.

CONCLUSIONS

Innominate vein occlusion and stenosis associated with chylous effusion are amenable to transcatheter revascularization and/or angioplasty, consistently leading to improvement, if not full resolution of chylothorax.

Fatal pulmonary embolism complicating a postoperative chylothorax despite adequate thromboprophylaxis

Chylothorax is a recognized complication of intrathoracic surgery, but its occurrence after coronary artery bypass grafting (CABG) is very rare. We report a case of a fatal pulmonary embolism as a complication of chylothorax following CABG. The patient was an 82-year-old woman who presented with increasing chest pain 2 weeks after discharge after an uncomplicated CABG. A computerized tomography (CT) scan with contrast angiogram showed a left-sided pleural effusion and no concurrent pulmonary embolus. Analysis of the pleural effusion revealed a chylothorax, which was treated with chest tube drainage and total parenteral nutrition followed by an oral medium-chain fatty acid diet. The patient improved steadily but, on day 6, she developed acute hypoxemic respiratory failure and shock. A CT angiogram revealed a massive pulmonary embolus and, despite thrombolysis, the patient died. Autopsy confirmed an acute saddle embolus in the pulmonary trunk. The patient had received appropriate venous thromboembolism prophylaxis with subcutaneous unfractionated heparin during her hospital course. This is the first reported case of a fatal pulmonary embolism that occurred in the setting of a post-CABG chylothorax in adults. The occurrence of this complication despite unfractionated heparin thromboprophylaxis may suggest a role for other, more effective medications, such as low molecular weight heparin or fondaparinux in patients with chylothorax.

Clinical syndromes associated with acquired antithrombin deficiency via microvascular leakage and the related risk of thrombosis

Antithrombin (AT) is a 65kDa glycoprotein belonging to a group of inhibitory factors known as serpins (serine protease inhibitors). It plays a critical role in the inhibition of coagulation and inflammation processes within the environment of the vascular endothelium. Inadequate levels of functional AT in plasma results in an increased risk of thrombotic events, both venous and arterial. AT deficiency can be inherited or acquired. Congenital AT deficiency is the most severe inherited thrombophilic condition with an odds ratio of 20 for the increased risk of venous thrombosis. Acquired AT deficiency occurs in a variety of physiologic and pathologic medical conditions with similar risks of increased thrombosis. In this article, we review clinical settings characterized by an acquired AT deficiency largely or partly subsequent to protein microvascular leakage. Other different mechanisms of AT depletion are implied in some clinical conditions together with endothelial loss, and, therefore, outlined. In addition, we provide a description of the current knowledge on the specific mechanisms underlying endothelial AT leakage and on the consequences of this protein decrease, specifically looking at thrombosis. We identify potential directions of research that might prove useful in patients with acquired AT deficiency.

Chylothorax in children with congenital heart disease: incidence of thrombosis

Postoperative chylothorax is a frequently encountered pathology occurring in up to 4% of patients undergoing surgery for repair of congenital heart disease. Symptomatic thrombosis is associated with chylothorax and may contribute to its severity and duration. Furthermore, vessel thrombosis resulting in persistent vessel occlusion may impede future treatments, diagnostic studies and cardio-surgical interventions. The objective of this study was to determine the incidence of upper system thrombosis in pediatric congenital heart patients with confirmed chylothorax with ultrasound screening of all patients diagnosed with chylothorax. All pediatric patients with confirmed with chylothorax underwent doppler ultrasound of the upper venous system as per hospital standard. This retrospective cohort study enrolled all children between February 1, 2010-August 2012, post cardiac surgery with confirmed chylothorax to determine the incidence of all thrombosis. There were 1396 children who underwent 1396 cardiac surgical procedures during the study time with 760 undergoing cardiopulmonary bypass. Development of chylothorax occurred in 54 of 1396, 3.9% (95%CI 3.0;5.0) procedures in all children. In those children with chylothorax, 28 of 54 episodes, 51.8% (95%CI 38.9;64.6) had confirmed VTE. The 51.8% incidence in this study demonstrates a 2.6 fold increase in risk of thrombosis compared to 20% in children with heart disease and central venous lines and may result in serious clinical consequences. The contribution of upper venous system thrombosis to chylothorax is unknown. Often, clinical suspicion of chylothorax exists, however the lack of a standardized approach to objective diagnosis results in delayed confirmation. Approaches to therapy either treatment of confirmed thrombosis or prevention of thrombosis in patients with chylothorax require formal evaluation. Future studies are urgently needed.

Congenital extensive central venous thrombosis with chylous ascites and chylothoraces

We describe a case of congenital extensive central venous thrombosis presenting as polyhydramnios and massive ascites, requiring amnioreduction prenatally and refractory chylous ascites and chylothoraces postnatally. Echocardiography, computed tomography angiogram (CTA), and magnetic resonance venogram (MRV) were helpful in defining the nature and extent of the lesion. The patient underwent staged procedures of repeated abdominal paracentesis, chest drain insertion, and right internal jugular vein exploration initially. Subsequently, open thromboembolectomy from the upper venous system veins and pericardial patch angioplasty of the right internal jugular and right innominate veins were required and managed by catheter-directed thrombolysis for the residual thrombosis with successful recovery.

Obstruction of the superior vena cava after neonatal extracorporeal membrane oxygenation: association with chylothorax and outcome of transcatheter treatment

BACKGROUND

Obstruction of the superior vena cava is one of the potential complications of neonatal extracorporeal membrane oxygenation. Chylothorax is a known complication of surgery involving the thoracic cavity in children, and of extracorporeal membrane oxygenation. The aim of this study was to evaluate the association between chylothorax and superior vena cava obstruction after neonatal extracorporeal membrane oxygenation.

METHODS AND RESULTS

Twenty-two patients diagnosed with superior vena cava obstruction at ≤ 6 months of age (median 1.8 months) after neonatal extracorporeal membrane oxygenation were compared with a randomly selected cohort of 44 neonatal extracorporeal membrane oxygenation patients without superior vena cava obstruction. Among patients with superior vena cava obstruction, 18 underwent extracorporeal membrane oxygenation for respiratory disease and four for cardiac insufficiency. Chylothorax was more prevalent among patients with superior vena cava obstruction than controls (odds ratio 9.4 [2.2-40], p = .01) and was associated with extension of obstruction into the left innominate vein. Patients with superior vena cava obstruction were supported by extracorporeal membrane oxygenation for a longer duration than controls. Nineteen patients with superior vena cava obstruction (86%) underwent transcatheter balloon angioplasty and/or stent implantation (median 7 days after diagnosis), which decreased the superior vena cava pressure and superior vena cava-to-right atrium pressure gradient and increased the superior vena cava diameter (all p < 0.001). There were no serious procedural adverse events. Six study patients died within 30 days of the diagnosis of superior vena cava obstruction (including three of nine with chylothorax), which did not differ from controls. During a median follow-up of 2.7 yrs, two additional patients died and nine underwent 14 superior vena cava reinterventions.

CONCLUSIONS

Among neonates treated with extracorporeal membrane oxygenation, superior vena cava obstruction is associated with an increased risk of chylothorax. In neonates with chylothorax after extracorporeal membrane oxygenation, evaluation for superior vena cava obstruction may be warranted. Although mortality is high in this population, transcatheter treatment can relieve superior vena cava obstruction and facilitate symptomatic improvement.

Chylothorax after surgery for congenital heart disease

PURPOSE OF REVIEW

Postoperative chylothorax is a frequently encountered pathology in the cardiac intensive care unit. The continuous loss of chyle is a challenging problem to treat and is associated with increased morbidity and mortality. The purpose of this article is to review the pathophysiology of chylothorax in patients after surgery for congenital heart disease, its implications and the current therapies available.

RECENT FINDINGS

The incidence of chylothorax has been increasing over the last two decades. Multiple uncontrolled case series describe octreotide as an effective treatment, and octreotide usage is increasing around the world for patients nonresponsive to dietary modifications. Most centers reserve surgical treatment for patients nonresponsive after 4 weeks of medical treatment. Less-invasive surgical procedures such as thoracic duct ligation by video-assisted thoracoscopy are gaining popularity.

SUMMARY

Chylothorax is commonly seen in children after surgery for congenital heart disease. The multiple and serious complications associated with chylous effusions are well known. Conservative therapy with diet modification and octreotide remain the standard initial approach. Thoracic duct ligation has been reported as a highly successful treatment but has considerable risk. Thus, this procedure should be reserved for patients nonresponsive to conservative therapy.

Chylothorax after congenital diaphragmatic hernia repair: a population-based study

PURPOSE

Chylothorax is a recognized complication of congenital diaphragmatic hernia (CDH) repair. Our aims were to describe the frequency and outcomes of chylothorax and to seek predictors of chylothorax occurrence within a population-based CDH cohort.

METHODS

Records for patients with CDH born between 2006 and 2010 were abstracted from a national database and were compared according to presence/absence of postrepair chylothorax. Univariate, and where appropriate, multivariate analyses were performed for group comparisons and chylothorax outcome prediction.

RESULTS

Of 243 newborns with CDH surviving to repair, 11 (4.5%) developed a chylothorax. All were managed nonoperatively. Factors predictive of chylothorax outcome on multivariate analysis included need for preoperative transfusion (odds ratio, 13.2; 95% confidence interval, 2.1-83.7; P = .006) and preoperative high-frequency oscillatory ventilation (odds ratio, 7.1; 95% confidence interval, 1.6-31.2; P = .01). Preoperative vasopressor use was significant on univariate analysis only. The groups were comparable for survival, length of stay, and duration of ventilation, but chylothorax patients had prolonged total parenteral nutrition (53 vs 21 days, P = .006) and more central line days (46 vs 24 days, P = .03).

CONCLUSIONS

Our data suggest that severity of preoperative cardiopulmonary derangement and not anatomical or technical factors predicts chylothorax occurrence after CDH repair.

Chylothorax after surgery on congenital heart disease in newborns and infants -risk factors and efficacy of MCT-diet

Objectives

To analyze risk factors for chylothorax in infants after congenital heart surgery and the efficacy of median chain triglyceride diet (MCT). To develop our therapeutic pathway for the management of chylothorax.

Patients and methods

Retrospective review of the institutional surgical database and patient charts including detailed perioperative informations between 1/2000 and 10/2006. Data analyzing with an elimination regression analysis.

Results

Twenty six out of 282 patients had chylothorax (=9.2%). Secondary chest closure, low body weight, small size, longer cardiopulmonary bypass (242 ± 30 versus 129 ± 5 min) and x-clamp times (111 ± 15 versus 62 ± 3 min) were significantly associated with chylothorax (p < 0.05). One patient was cured with total parenteral nutrition (TPN) and one without any treatment. 24 patients received MCT-diet alone, which was successful in 17 patients within 10 days. After conversion to regular alimentation within one week only one chylothorax relapsed. Out of 7 patients primarily not responsive to MCT-diet, 2 were successfully treated by lysis of a caval vein thrombosis, 2 by TPN + pleurodesis + supradiaphragmatic thoracic duct ligation, one by octreotide treatment, and two patients finally died.

Conclusions

Chylothorax may appear due to injury of the thoracic duct, due to venous or lymphatic congestion, central vein thrombosis, or diffuse injury of mediastinal lymphatic tissue in association with secondary chest closure. Application of MCT alone was effective in 71%, and more invasive treatments like TPN should not be used in primary routine. After resolution of chylothorax, MCT-diet can be converted to regular milk formula within one week and with very low risk of relapse.