Successful treatment of plastic bronchitis by selective lymphatic embolization in a Fontan patient

Lymphatic Disorder Management in Pediatric Patients With Congenital Heart Disease in European Pediatric Cardiology Centers: Current Status, Disparities, and Future Considerations

BACKGROUND

Lymphatic disorders such as protein-losing enteropathy, plastic bronchitis, and chylothorax are important complications of the Fontan circulation and ultimately result in an increased risk of early death. Several European centers are now performing lymphatic procedures. The aim of this study is to map the extent of these lymphatic disorders and treatments provided across European pediatric cardiology centers.

METHODS AND RESULTS

A survey was circulated to 49 European pediatric cardiology centers consisting of 37 questions including a mix of binary, categorical, and continuous variables. Thirty-one centers (63%) participated in the study, performing a median of 250 (interquartile range, 178 - 313) cardiopulmonary bypass procedures per year. Chylothorax emerged as the most prevalent lymphatic disorder followed by protein-losing enteropathy and plastic bronchitis. The most common diagnostic investigation method was noncontrast magnetic resonance lymphangiography (52%). Eleven centers (35%) conducted lymphatic interventions with a median of 3 (interquartile range, 1 - 4) procedures per year and 12 (interquartile range, 5 - 15) interventions in total per center.

CONCLUSIONS

This study confirms the rarity of and variation in treatment approaches for lymphatic disorders across Europe. With at least 11 centers offering lymphatic interventions, the adoption of these procedures is on the rise in Europe. To improve the quality of care and treatment outcomes for these complex patients, it is crucial to consider evidence-based lymphatic diagnostics, interventional lymphatic procedures, and the centralization of services in Europe.

Advances in Diagnostic and Interventional Catheterization in Adults with Fontan Circulation

Over the past five decades, the Fontan procedure has been developed to improve the life expectancy of patients with congenital heart defects characterized by a functionally single ventricle. The Fontan circulation aims at redirecting systemic venous return to the pulmonary circulation in the absence of an impelling subpulmonary ventricle, which makes this physiology quite fragile and leads to several long-term complications. Despite the importance of hemodynamic assessment through cardiac catheterization in the management and follow-up of these patients, a thorough understanding of the ultimate functioning of this type of circulation is lacking, and the interpretation of the hemodynamic data is often complex. In recent years, new tools such as combined catheterization with cardiopulmonary exercise testing have been incorporated to improve the understanding of the hemodynamic profile of these patients. Furthermore, extensive percutaneous treatment options have been developed, addressing issues ranging from obstructive problems in Fontan pathway and acquired shunts through compensatory collaterals to the percutaneous treatment of lymphatic circulation disorders and transcatheter edge-to-edge repair of atrioventricular valves. The aim of this review is to detail the various tools used in cardiac catheterization for patients with Fontan circulation, analyze different percutaneous treatment strategies, and discuss the latest advancements in this field.

Clinical impact of novel CMR technology on patients with congenital heart disease. A scientific statement of the Association for European Pediatric and Congenital Cardiology (AEPC) and the European Association of Cardiovascular Imaging (EACVI) of the ESC

Cardiovascular magnetic resonance (CMR) imaging is recommended in patients with congenital heart disease (CHD) in clinical practice guidelines as the imaging standard for a large variety of diseases. As CMR is evolving, novel techniques are becoming available. Some of them are already used clinically, whereas others still need further evaluation. In this statement the authors give an overview of relevant new CMR techniques for the assessment of CHD. Studies with reference values for these new techniques are listed in the supplement.

Medical Therapy for Heart Failure in Adult Congenital Heart Disease Patients

There is an increasing recognition of heart failure among adults with congenital heart disease as a result of the advancements in medical, interventional, and surgical care. The long-term consequences of palliative therapy in infancy, childhood, and adulthood are incompletely understood. Medical therapy, including pharmacologic and device therapies, have been used for the treatment of heart failure. This review summarizes care strategies that have been applied within the spectrum of adults with congenital heart disease, including failing systemic ventricles, single ventricles, and Eisenmenger physiology.

Lymphatic interventions in congenital heart disease

Congenital heart disease affects 1/100 live births and is one of the most common congenital abnormalities. The relationship between congenital heart disease and lymphatic abnormalities and/or dysfunction is well documented and can be grossly divided into syndromic and non-syndromic etiologies. In patients with genetic syndromes (as examples listed above), there are known primary abnormal lymphatic development leading to a large pleiotropic manifestation of lymphatic dysfunction. Non-syndromic patients, or those without clear genetic etiologies for their lymphatic dysfunction, are often thought to be secondary to physiologic abnormalities as sequelae of congenital heart disease and palliative surgeries. Patients with congenital heart disease and lymphatic dysfunction have a wide variety of clinical manifestations for which there were not many therapeutic interventions available. The development of new imaging techniques allows us to understand better the pathophysiology of these problems and to develop different percutaneous interventions aiming to restore normal lymphatic function.

Percutaneous procedures for central lymphatic conduction disorders

Percutaneous endovascular techniques established in interventional cardiology and radiology are well-suited for managing lymphatic conduction disorders. In this article, we provide a synopsis of technical aspects of these procedures, including access of the thoracic duct, selective lymphatic embolization, and management of thoracic duct obstruction. In aggregate, these techniques have developed into an integral component of multidisciplinary management of these complex diseases.

Preliminary report of a thoracic duct-to-pulmonary vein lymphovenous anastomosis in swine: A novel technique and potential treatment for lymphatic failure

OBJECTIVE

The thoracic duct is the largest lymphatic vessel in the body, and carries fluid and nutrients absorbed in abdominal organs to the central venous circulation. Thoracic duct obstruction can cause significant failure of the lymphatic circulation (i.e., protein-losing enteropathy, plastic bronchitis, etc.). Surgical anastomosis between the thoracic duct and central venous circulation has been used to treat thoracic duct obstruction but cannot provide lymphatic decompression in patients with superior vena cava obstruction or chronically elevated central venous pressures (e.g., right heart failure, single ventricle physiology, etc.). Therefore, this preclinical feasibility study sought to develop a novel and optimal surgical technique for creating a thoracic duct-to-pulmonary vein lymphovenous anastomosis (LVA) in swine that could remain patent and preserve unidirectional lymphatic fluid flow into the systemic venous circulation to provide therapeutic decompression of the lymphatic circulation even at high central venous pressures.

METHODS

A thoracic duct-to-pulmonary vein LVA was attempted in 10 piglets (median age 80 [IQR 80-83] days; weight 22.5 [IQR 21.4-26.8] kg). After a right thoracotomy, the thoracic duct was mobilized, transected, and anastomosed to the right inferior pulmonary vein. Animals were systemically anticoagulated on post-operative day 1. Lymphangiography was used to evaluate LVA patency up to post-operative day 7.

RESULTS

A thoracic duct-to-pulmonary vein LVA was successfully completed in 8/10 (80.0%) piglets, of which 6/8 (75.0%) survived to the intended study endpoint without any complication (median 6 [IQR 4-7] days). Initially, 2/10 (20.0%) LVAs were aborted intraoperatively, and 2/10 (20.0%) animals were euthanized early due to post-operative complications. However, using an optimized surgical technique, the success rate for creating a thoracic duct-to-pulmonary vein LVA in six animals was 100%, all of which survived to their intended study endpoint without any complications (median 6 [IQR 4-7] days). LVAs remained patent for up to seven days.

CONCLUSION

A thoracic duct-to-pulmonary vein LVA can be completed safely and remain patent for at least one week with systemic anticoagulation, which provides an important proof-of-concept that this novel intervention could effectively offload the lymphatic circulation in patients with lymphatic failure and elevated central venous pressures.

Lymphatic failure and lymphatic interventions: Knowledge gaps and future directions for a new frontier in congenital heart disease

Lymphatic failure is a broad term that describes the lymphatic circulation's inability to adequately transport fluid and solutes out of the interstitium and into the systemic venous circulation, which can result in dysfunction and dysregulation of immune responses, dietary fat absorption, and fluid balance maintenance. Several investigations have recently elucidated the nexus between lymphatic failure and congenital heart disease, and the associated morbidity and mortality is now well-recognized. However, the precise pathophysiology and pathogenesis of lymphatic failure remains poorly understood and relatively understudied, and there are no targeted therapeutics or interventions to reliably prevent its development and progression. Thus, there is growing enthusiasm towards the development and application of novel percutaneous and surgical lymphatic interventions. Moreover, there is consensus that further investigations are needed to delineate the underlying mechanisms of lymphatic failure, which could help identify novel therapeutic targets and develop innovative procedures to improve the overall quality of life and survival of these patients. With these considerations, this review aims to provide an overview of the lymphatic circulation and its vasculature as it relates to current understandings into the pathophysiology and pathogenesis of lymphatic failure in patients with congenital heart disease, while also summarizing strategies for evaluating and managing lymphatic complications, as well as specific areas of interest for future translational and clinical research efforts.

Octreotide improves human lymphatic fluid transport a translational trial

OBJECTIVES

Chylothorax is a complex condition and many different pharmacological agents have been tried as treatment. Octreotide is used off-label to treat chylothorax, but the efficacy of octreotide remains unclear. A decrease in lymph production is suggested as the mechanism. In this cross-over study, we explore the direct effect of octreotide on human lymphatic drainage.

METHODS

Pre-clinical: the effect of octreotide on force generation was assessed during acute and prolonged drug incubation on human lymphatic vessels mounted in a myograph. Clinical: in a double-blinded, randomized, cross-over trial including 16 healthy adults, we administered either octreotide or saline as an intravenous infusion for 2.5 h. Near-infrared fluorescence imaging was used to examine spontaneous lymphatic contractions and lymph pressure in peripheral lymphatic vessels and plethysmography was performed to assess the capillary filtration rate, capillary filtration coefficient and isovolumetric pressures of the lower leg.

RESULTS

Pre-clinical: human thoracic duct (n = 12) contraction rate was concentration-dependently stimulated by octreotide with a maximum effect at 10 and 100 nmol/l in the myograph chamber. Clinical: spontaneous lymphatic contractions and lymph pressure evaluated by near-infrared fluorescence did not differ between octreotide or placebo (P = 0.36). Plethysmography revealed similar capillary filtration coefficients (P = 0.057), but almost a doubling of the isovolumetric pressures (P = 0.005) during octreotide infusion.

CONCLUSIONS

Octreotide stimulated lymphatic contractility in the pre-clinical setup but did not affect the spontaneous lymphatic contractions or lymph pressure in healthy individuals. Plethysmography revealed a doubling in the isovolumetric pressure. These results suggest that octreotide increases lymphatic drainage capacity in situations with high lymphatic afterload.

Five decades of Fontan palliation: What have we learned? What should we expect?

The Fontan procedure is the final palliative surgery in a series of staged surgeries to reroute the systemic venous blood flow directly to the lungs, with the ventricle(s) pumping oxygenated blood to the body. Advances in medical and surgical techniques have improved patients' overall survival after the Fontan procedure. However, Fontan-associated chronic comorbidities are common. In addition to chronic cardiac dysfunction and arrhythmias, complications involving other organs such as the liver, lungs, intestine, lymphatic system, brain, and blood frequently occur. This narrative review focuses on the immediate and late consequences in children, pregnant women, and other adults with Fontan circulation. In addition, we describe the technical advancements that might change the way single-ventricle patients are managed in future.

Transvenous retrograde thoracic duct embolization for effective treatment of recurrent plastic bronchitis after fontan palliation

We report the case of a 5.5-year-old patient (16 kg/105 cm) who presented with plastic bronchitis (PB) refractory to conservative treatment 3 months after completion of Fontan palliation. Bi-inguinal transnodal fluoroscopy-guided lymphangiogram confirmed the chylous leak originating from the thoracic duct (TD) into the chest and did not opacify any central lymphatic vessel for direct transabdominal puncture. Retrograde transfemoral approach was adopted to catheterize the TD and selectively embolize its caudal portion using microcoils and liquid embolic adhesive. Recurrence of symptoms after 2 months indicated a redo catheterization to occlude the TD entirely using the same technique. The procedure was successful and the patient was discharged after 2 days with sustained clinical improvement at 24 months postoperative. In the context of refractory PB, end-to-end transvenous retrograde embolization of the TD appears to be an interesting alternative to more complex interventions such as transabdominal puncture, decompression, or surgical ligation of the TD.

Current diagnostic and therapeutic strategies for the management of lymphatic insufficiency in patients with hypoplastic left heart syndrome

Children with hypoplastic left heart syndrome share unique hemodynamic features that alter lymphatic integrity at all stages of palliation. Lymphatic congestion is almost universal in this patient group to some extent. It may lead to reversal of lymphatic flow, the development of abnormal lymphatic channels and ultimately decompression and loss of protein rich lymphatic fluid into extra lymphatic compartments in prone individuals. Some of the most devastating complications that are associated with single ventricle physiology, notably plastic bronchitis and protein losing enteropathy, have now been proven to be lymphatic in origin. Based on the new pathophysiologic concept new diagnostic and therapeutic strategies have recently been developed. Dynamic contrast magnetic resonance lymphangiography is now mainstay in diagnosis of lymphatic insufficiency and allows a thorough assessment of anatomy and function of the main lymphatic compartments through intranodal, intrahepatic and intramesenteric lymphatic imaging. Contrast enhanced ultrasound can evaluate thoracic duct patency and conventional fluoroscopic lymphangiography has been refined for evaluation of patients where magnetic resonance imaging cannot be performed. Novel lymphatic interventional techniques, such as thoracic duct embolization, selective lymphatic duct embolization and liver lymphatic embolization allow to seal abnormal lymphatic networks minimally invasive and have shown to resolve symptoms. Innominate vein turn-down procedures, whether surgical or interventional, have been designed to reduce lymphatic afterload and increase systemic preload effectively in the failing Fontan circulation. Outflow obstruction can now be managed with new microsurgical techniques that create lympho-venous anastomosis. Short term results for all of these new approaches are overall promising but evidence is sparse and long-term outcome still has to be defined. This review article aims to summarize current concepts of lymphatic flow disorders in single ventricle patients, discuss new emerging diagnostic and therapeutic strategies and point out lacks in evidence and needs for further research on this rapidly growing topic.

Lymphatic anomalies in congenital heart disease

Congenital heart disease can lead to various lymphatic complications including traumatic leaks, lymphatic overproduction, conduction abnormalities or lymphedema. Advancements in the imaging of central lymphatics and guided interventions have improved outcomes in these children. Dynamic contrast-enhanced magnetic resonance (MR) lymphangiography allows for the assessment of abnormal lymphatic drainage. This technique is preferred for evaluating lymphatic conditions such as plastic bronchitis, chylothorax, chyloptysis, chylopericardium, protein-losing enteropathy and chylous ascites, among other lymphatic disorders. In this review, we discuss lymphatic abnormalities encountered on MRI in children with congenital heart disease. We also briefly review treatment options.

CT Features of Lymphatic Plastic Bronchitis in Adults: Correlation with Multimodality Lymphatic Imaging

Purpose

To distinguish CT patterns of lymphatic and nonlymphatic causes of plastic bronchitis (PB) through comparison with lymphatic imaging.

Materials and Methods

In this retrospective study, chest CT images acquired prior to lymphatic workup were assessed in 44 patients with PB from January 2014 to August 2020. The location and extent of ground-glass opacity (GGO) was compared with symptoms and lymphatic imaging. Statistical analysis was performed using descriptive statistics, logistic regression, Pearson correlation coefficient, and unweighted κ coefficient for interobserver agreement. Sensitivity and specificity of GGO for lymphatic PB were calculated.

Results

Lymphatic imaging was performed in 44 patients (median age, 52 years ± 21 [IQR]; 23 women): 35 with lymphatic PB and nine with nonlymphatic PB. GGO was more frequently observed in patients with lymphatic PB than in those with nonlymphatic PB (91% [32 of 35] vs 33% [three of nine]; P < .001). Univariate logistic regression confirmed this result by showing that GGO was a significant predictor of lymphatic PB (odds ratio, 21 (95% CI: 3.8, 159.7). The model areas under the receiver operating characteristic curve (AUCs) of GGO unadjusted and adjusted for demographics were 0.79 and 0.86, respectively. The location of GGO correlated with lymphatic imaging and bronchoscopic findings. Overall sensitivity and specificity of GGO for lymphatic PB were 91% (32 of 35; 95% CI: 76, 98) and 67% (six of nine; 95% CI: 30, 93), respectively.

Conclusion

Patients with lymphatic PB predominantly had multifocal GGO with or without a "crazy paving" pattern; identification of GGO should prompt lymphatic workup in this frequently misdiagnosed condition.Keywords: Lymphography, Lymphatic, CT, Tracheobronchial Tree, Thorax© RSNA, 2022See also commentary by Kligerman and White in this issue.

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.

Lymphatic Disorders in Patients With Single Ventricle Heart Disease

Lymphatic abnormalities in patients with single ventricle physiology can lead to early Fontan failure and severe Fontan complications, such as protein-losing enteropathy (PLE), plastic bronchitis (PB), chylothorax, and edema. Recent developments in lymphatic imaging and interventions have shed new light on the lymphatic dysfunction in this patient population and the role of the lymphatic circulation in PLE, PB, and chylothorax. In this study, we reviewed some of the latest developments in this field and discuss new treatment options for these patients.

Reappraisal of lung manifestations in the setting of Fontan circulation

Fontan circulation is a well-established palliation in patients with functional single ventricles. Absence of a sub-pulmonary pumping chamber creates a unique physiology in which blood flow is mainly guided by negative intrathoracic and elevated central venous pressures. Various pulmonary anatomic or pathophysiologic changes can jeopardize optimal Fontan circulation. Long-term survival of patients who have undergone the contemporary total cavopulmonary connection is satisfactory. Thorough literature review in conjunction with accumulated clinical experience can lead clinicians to extract conclusions regarding Fontan and lung interactions indicating the purpose of this review.

Intrahepatic Dynamic Contrast-Enhanced Magnetic Resonance Lymphangiography: Potential Imaging Signature for Protein-Losing Enteropathy in Congenital Heart Disease

Background

Protein‐losing enteropathy (PLE) is a significant cause of morbidity and mortality in congenital heart disease patients with single ventricle physiology. Intrahepatic dynamic contrast‐enhanced magnetic resonance lymphangiography (IH‐DCMRL) is a novel diagnostic technique that may be useful in characterizing pathologic abdominal lymphatic flow in the congenital heart disease population and in diagnosing PLE. The objective of this study was to characterize differences in IH‐DCMRL findings in patients with single ventricle congenital heart disease with and without PLE.

Methods and Results

This was a single‐center retrospective study of IH‐DCMRL findings and clinical data in 41 consecutive patients, 20 with PLE and 21 without PLE, with single ventricle physiology referred for lymphatic evaluation. There were 3 distinct duodenal imaging patterns by IH‐DCMRL: (1) enhancement of the duodenal wall with leakage into the lumen, (2) enhancement of the duodenal wall without leakage into the lumen, and (3) no duodenal involvement. Patients with PLE were more likely to have duodenal involvement on IH‐DCMRL than patients without PLE (P<0.001).

Conclusions

IH‐DCMRL findings of lymphatic enhancement of the duodenal wall and leakage of lymph into the duodenal lumen are associated with PLE. IH‐DCMRL is a useful new modality for characterizing pathologic abdominal lymphatic flow in PLE and might be useful as a risk‐assessment tool for PLE in at‐risk patients.

Fontan-associated plastic bronchitis waitlist and heart transplant outcomes: A PHTS analysis

Plastic bronchitis is a rare post-Fontan complication with limited treatment options. Heart transplantation has evolved as a potential curative option, but outcomes have not been well-defined. This study aims to assess contemporary waitlist and post-transplant outcomes in patients with plastic bronchitis. All Fontan patients were identified in the PHTS database (2010 - 2018). Waitlist and post-transplant outcomes were compared between Fontan patients with and without plastic bronchitis. Competing outcomes and Kaplan-Meier analyses were used to assess the impact of plastic bronchitis on waitlist and post-transplant survival. A secondary analysis excluded those with PLE from the comparison cohort. Of 645 Fontan patients listed for heart transplant, 69 (11%) had plastic bronchitis. At listing, patients with plastic bronchitis were younger (8.9 vs 11.1 years, P = .02), but had few other differences in baseline characteristics. A fewer Fontan patients with plastic bronchitis were listed in the more recent era (46 [15.4%] in 2010-2014 vs 23 [6.6%] in 2015-2018, P < .01). Overall, there was no difference in waitlist (P = .30) or post-transplant (P = .66) survival for Fontan patients with and without plastic bronchitis. The results were similar after excluding patients with PLE. Contrary to prior reports, this relatively large series showed that plastic bronchitis did not have a negative impact on survival to or after heart transplantation in Fontan patients. Our study also found a 50% reduction in listing in the current era, which may indicate evolution in management of Fontan patients.

The Lymphatic System in the Fontan Patient-Pathophysiology, Imaging, and Interventions: What the Anesthesiologist Should Know

The Fontan surgery was developed as a palliative intervention for congenital heart disease (CHD) patients with single-ventricle physiology who are not candidates for a biventricular repair. Improvements in the surgery and medical management of these patients have increased survival, yet this population remains at risk for complications and end-organ dysfunction due to Fontan failure. Lymphatic vessels maintain a fluid balance within the extracellular space, participate in fat reabsorption from the small intestine, and play an important role in the body's immune response. Altered Starling forces at the capillary level, capillary leak, and lymphatic obstruction contribute to lymphatic dysfunction in patients with Fontan physiology. These lymphatic complications include edema, pleural effusions, plastic bronchitis (PB), and protein-losing enteropathy (PLE). Over the past decade, there have been innovations in lymphatic imaging. These new imaging techniques include noncontrast magnetic resonance (MR) lymphangiography, intranodal lymphangiography (IL), dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL), and liver lymphangiography. These imaging techniques help in delineating anatomy and guiding the appropriate therapeutic approach. Lymphatic interventions then may be performed to decompress the lymphatic system or to identify and occlude abnormal lymphatic vessels and drainage pathways. The anesthesiologist should have an understanding of the effects of lymphatic disorders on the Fontan circulation and apply appropriate management techniques for the associated interventions. The Fontan surgery was developed as a palliative intervention for CHD patients with single-ventricle physiology who are not candidates for a biventricular repair. The surgery creates a series systemic and pulmonary circulation with the energy necessary to provide gradient-driven pulmonary blood flow generated by the ventricle.¹ In the past decades, improvements in the surgery and medical management of these patients have increased survival, with 30-year survival rates close to 85%.² Despite these improvements, this population remains at risk for complications and end-organ dysfunction due to Fontan failure, which is characterized by elevated systemic venous pressures and low cardiac output. These complications include arrhythmias, cardiac dysfunction, ascites, liver fibrosis/cirrhosis, renal dysfunction, pulmonary failure, and lymphatic complications such as edema, pleural effusions, PB, and PLE. Complications ultimately contribute to increased risk for hospitalization, death, and need for heart transplantation.^3,4 For this reason, there has been increasing interest in the role of abnormal lymphatic circulation in the genesis of Fontan failure. The authors characterize the lymphatic pathophysiology associated with Fontan physiology and review the imaging and interventional strategies used to treat these patients.

Liver lymphatic anatomy and role in systemic lymphatic disease

Objectives

To characterize hepatic to systemic lymphatic connections in patients with systemic lymphatic disease using intra-hepatic lymphangiography and to compare outcomes after lymphatic intervention.

Methods

In this retrospective study, patients with intra-hepatic lymphangiography from May 2014 – April 2019 at our institution were included. Imaging review was performed and hepatic lymphatic connections and flow patterns were characterized. Clinical data were reviewed and comparisons between patients undergoing lymphatic intervention with or without abnormal hepatic lymphatics were performed.

Results

During the study period, 105 patients underwent intra-hepatic lymphangiography. Primary clinical presentation included ascites (19/105), chylothorax (27/105), plastic bronchitis (PB) (17/105), and protein losing enteropathy (PLE) (42/105). Five categories of hepatic lymphatic connections and flow patterns were identified (%): normal (25%, 26/105), hepatoperitoneal (12%, 13/105), hepatopulmonary (10.5%, 11/105), hepatomesenteric (7.5%, 8/105), and hepatoduodenal (41%, 43/105) with four patients having more than one abnormal pattern. A comparison between clinical presentation and imaging category revealed an increased likelihood of having ascites with hepatoperitoneal (p < .0001), chylothorax/PB with hepatopulmonary (p = .01), and PLE with hepatoduodenal (p < .001) connections. Seventy-six patients had a lymphatic intervention, 24% with normal, and 76% with abnormal liver lymphatics. There was no difference in length of hospital stay or mortality between the two groups, but there was a prolonged time to symptom resolution (p = .006) and persistent symptoms after 6 months (5% vs 44%, p = .002) in the group with abnormal liver lymphatics.

Conclusion

We identified five liver lymphatic imaging categories with a substantial correlation to presenting lymphatic disease. Abnormal imaging patterns correlated with increased morbidity. Evaluation of liver lymphatics should be considered in patients with a systemic lymphatic disease if central lymphatic imaging is normal.

Key Points

• We identified five liver lymphatic imaging patterns: normal, hepatoperitoneal, hepatomesenteric, hepatopulmonary, and hepatoduodenal.

• Imaging patterns were correlated with disease presentation (normal – chylothorax/PB, hepatoperitoneal – ascites/chylothorax, hepatopulmonary – chylothorax/PB, hepatoduodenal – PLE).

• Abnormal imaging patterns correlated with increased morbidity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08098-z.

Abnormal Pulmonary Lymphatic Flow on Novel Lymphangiographic Imaging Supports a Common Etiology of Lymphatic Plastic Bronchitis and Nontraumatic Chylothorax

Background: This study evaluates whether dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) and thoracic duct lymphangiography (TDL) findings in adults with lymphatic plastic bronchitis (PB) and/or nontraumatic chylothorax (NTC) support a shared pathophysiology. Materials and Results: Retrospective review of clinical and imaging findings in patients who underwent DCMRL and TDL at a single institution from March 2017 to March 2019. Categorical variables were compared with Fisher's exact test. Twenty-eight patients (median age 61 ± 21 years, 15 women) presenting with lymphatic PB (n = 13), NTC (n = 10), or both (n = 5) were included. Lymphatic imaging demonstrated pulmonary lymphatic perfusion (PLP) in all patients. A patent thoracic duct (TD) with retrograde flow was seen in 53.4% (7/13) of patients with PB, 60% (6/10) of patients with NTC, and 20% (1/5) of patients with both (p = 0.69). An occluded TD with retrograde flow was seen in 30.8% (4/13) of patients with PB, 30% (3/10) of patients with NTC, and 80% (4/5) of patients with both (p = 0.12). Similar patterns of PLP between DCMRL and TDL were seen in 96.2% (25/26) of patients. Conclusions: DCMRL and TDL demonstrated similar findings in patients with lymphatic PB and/or NTC, supporting a common etiology. This supports the hypothesis that the clinical presentation depends on the proximity of abnormal lymphatic vessels to the pleural cavity, resulting in chylothorax, or bronchial mucosa, resulting in PB.

Functional lymphatic reserve capacity is depressed in patients with a Fontan circulation

Background

Lymphatic abnormalities play a role in effusions in individuals with a Fontan circulation. Recent results using near‐infrared fluorescence imaging disclosed an increased contraction frequency of lymphatic vessels in Fontan patients compared to healthy controls. It is proposed that the elevated lymphatic pumping seen in the Fontan patients is necessary to maintain habitual interstitial fluid balance. Hyperthermia has previously been used as a tool for lymphatic stress test. By increasing fluid filtration in the capillary bed, the lymphatic workload and contraction frequency are increased accordingly. Using near‐infrared fluorescence imaging, the lymphatic functional reserve capacity in Fontan patients were explored with a lymphatic stress test.

Methods

Fontan patients (n = 33) were compared to a group of 15 healthy individuals of equal age, weight, and gender. The function of the superficial lymphatic vessels in the lower leg during rest and after inducing hyperthermia was investigated, using near‐infrared fluorescence imaging.

Results

Baseline values in the Fontan patients showed a 57% higher contraction frequency compared to the healthy controls (0.4 ± 0.3 min⁻¹ vs. 0.3 ± 0.2 min⁻¹, p = 0.0445). After inducing stress on the lymphatic vessels with hyperthermia the ability to increase contraction frequency was decreased in the Fontan patients compared to the controls (0.6 ± 0.5 min⁻¹ vs. 1.2 ± 0.8 min⁻¹, p = 0.0102).

Conclusions

Fontan patients had a higher lymphatic contraction frequency during normal circumstances. In the Fontan patients, the hyperthermia response is dampened indicating that the functional lymphatic reserve capacity is depressed. This diminished reserve capacity could be part of the explanation as to why some Fontan patients develop late‐onset lymphatic complications.

Innominate Vein Turn-down Procedure for Failing Fontan Circulation

After the Fontan, systemic venous hypertension induces pathophysiologic changes in the lymphatic system that can result in complications of pleural effusion, ascites, plastic bronchitis, and protein losing enteropathy. Advances in medical therapy and novel interventional approaches have not substantially improved the poor prognosis of these complications. A more physiological approach has been developed by decompression of the thoracic duct to the lower pressure common atrium with a concomitant increase of preload. Diverting the innominate vein to the common atrium increases the transport capacity of the thoracic duct, which in most patients enters the circulation at the left subclavian-jugular vein junction. Contrary to the fenestrated Fontan circulation, in which the thoracic duct is drained into the high pressure Fontan circulation, turn down of the innominate vein to the common atrium effectively decompresses the thoracic duct to the lower pressure system with "diastolic suctioning" of lymph. Innominate vein turn-down may be considered for medical-refractory post-Fontan lymphatic complications of persistent chylothorax, plastic bronchitis, and protein losing enteropathy. Prophylactic innominate vein turn-down may also be considered at time of the Fontan operation for patients that are higher risk for lymphatic complications.

Lymphatic Management in Single-Ventricle Patients

Lymphatic complications in patients with single ventricle include plastic bronchitis, protein-losing enteropathy, and chylous pleural effusion are a source of significant morbidity and mortality with historically limited therapeutic options. Novel lymphatic imaging techniques such as intranodal lymphangiography, dynamic contrast enhanced magnetic resonance lymphangiography and liver lymphangiography have allowed visualization of the lymphatic system and discovery of the pathophysiological mechanism of these conditions. This mechanism includes the combination of 2 factors: increased lymphatic flow in patients with elevated central venous pressure and presence of the lymphatic anatomical variant that allows the lymph to flow in close proximity to the serous (pleural space in chylothorax) or mucosal (plastic bronchitis and protein losing enteropathy) surfaces. Novel minimally invasive lymphatic interventional techniques, such as thoracic duct embolization, interstitial embolization and liver lymphatic embolization have allowed the obliteration of these abnormal lymphatic networks, resulting in resolution of the symptoms. Further refinement of the imaging techniques and interventional methods have subsequently allowed better patient selection and improved long term outcome of these procedures.

Noninvasive Imaging in Interventional Cardiology: Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a spectrum of left heart underdevelopment leaving the left side unable to support the systemic circulation. If active management is pursued, then the condition is managed with staged palliation to the Fontan circulation, leaving a systemic right ventricle. Through all surgical stages, and even after completion of Fontan, there are multiple areas that may require intervention, most frequently the branch pulmonary arteries which are essential to a successful Fontan circulation. Echocardiography is the mainstay of assessment, but there is an increasing use of magnetic resonance imaging (MRI) and computed tomography (CT) particularly in relation to extracardiac structures which can be more challenging with echocardiography. Both MRI and CT require set-up, experience and training, and usually sedation or anesthetic in smaller children, but can provide excellent imaging to guide interventions. Cardiac MRI is also able to quantify right ventricular (RV) function which can be challenging on echocardiography. This article describes the modalities available and their use in assessing patients with HLHS prior to catheter interventions.

Pediatric pulmonary lymphatic flow Disorders: Diagnosis and management

Pulmonary lymphatic flow disorders involve the abnormal lymphatic flow via lymphatic channels to the lungs and pleural space. Plastic bronchitis and chylothorax are the main complications of this abnormal lymphatic perfusion, which has been termed pulmonary lymphatic perfusion syndrome (PLPS). Following lymphatic access, dynamic contrast MR lymphangiography is the imaging modality of choice to diagnose these disorders. Management includes medical therapy, percutaneous interventions under fluoroscopy, and surgical interventions.

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.

Use of Contrast-Enhanced Ultrasound to Determine Thoracic Duct Patency

The aim of this study was to determine the feasibility of using contrast-enhanced ultrasound (CEUS) evaluation to determine thoracic duct (TD) outlet patency. Nine patients referred for lymphatic imaging and intervention underwent percutaneous intranodal ultrasound contrast injection and conventional lymphangiography (CL). Eight of 9 patients had a patent TD by CEUS and CL. One patient did not have a patent TD. There was 100% agreement between CEUS and CL. These results suggest that CEUS is an imaging modality that might be as accurate as CL in determining TD patency.

Abdominal lymphatic system visibility, morphology, and abnormalities in children as seen on routine MCRP and its association with immune-mediated diseases

PURPOSE

(1) To assess the visibility and diameters of the thoracic duct (TD) and cisterna chyli (CC) on MR cholangiopancreatography (MRCP) in children. (2) To evaluate for the presence of any lymphatic abnormalities and assess their association with diseases in which the immune system is implicated in etiopathogenesis.

METHODS

This retrospective study included 142 MRCPs performed in children 8-17 years old and without prior surgeries. Two radiologists reviewed all exams for visibility and diameters of the TD and CC, and presence of abnormal lymphatic collaterals. TD and CC diameters in various disease processes were compared using Student's t tests. The association of collaterals with immune-mediated diseases was assessed using Fisher's exact tests.

RESULTS

The TD and CC were seen in 134/142 (93.7%) cases with mean diameter of 3.25 ± 1.07 mm and 126/142 (88.7%) cases with mean diameter of 4.55 ± 1.37 mm respectively. The mean diameter of CC was larger in patients with portal hypertension (p = 0.021). There were no significant differences in the TD and CC diameters between immune-mediated and non-immune-mediated diseases. Retroperitoneal collaterals were seen in 41/142 (28.8%) of cases and were associated with both portal hypertension (p = 0.0019) and immune-mediated diseases (p = 0.0083).

CONCLUSION

The TD and CC can be visualized in the majority of children on routine MRCP images, and CC has larger diameter in patients with portal hypertension. The association of collaterals with immune-mediated diseases supports a potential role of the lymphatic system in the etiopathogenesis of immune-mediated diseases.

KEY POINTS

• The lymphatic system has been increasingly implicated in a number of inflammatory and immune-mediated diseases. • The abdominal lymphatic system can be visualized in the majority of children above 8 years on routine MRCP images. Similar to adult studies, the cisterna chyli is significantly larger in children with portal hypertension. • Retroperitoneal lymphatic collaterals, seen in 29% children, are associated with immune-mediated diseases, which supports the potential role of the lymphatic system in the pathogenesis of immune-mediated diseases.

Protein-losing enteropathy and plastic bronchitis after the Fontan procedure

OBJECTIVES

Protein losing enteropathy and plastic bronchitis are severe complications in Fontan circulation, with 5-year survival ranging from 46% to 88%. We report risk factors and outcomes of protein losing enteropathy and plastic bronchitis in patients undergoing the Fontan.

METHODS

We performed a retrospective analysis of 1561 patients from the Australia New Zealand Fontan Registry. Two end points were death and cardiac transplantation examined with Cox regression (if no competing risks) or cumulative incidence curves and cause-specific Cs regression.

RESULTS

A total of 55 patients with protein losing enteropathy/plastic bronchitis were included. Their median age at the Fontan was 5.7 years, and time to onset after the Fontan for protein losing enteropathy was 5.0 years and plastic bronchitis was 1.7 years. Independent predictors for developing protein losing enteropathy/plastic bronchitis were right-ventricular morphology with hypoplastic left-heart syndrome (hazard ratio, 2.30; confidence interval, 1.12-4.74), older age at Fontan (hazard ratio, 1.13; confidence interval, 1.03-1.23), and pleural effusions after Fontan (hazard ratio, 2.43; confidence interval, 1.09-5.41); left-ventricular morphology was protective (hazard ratio, 0.36; confidence interval, 0.18-0.70). In the protein losing enteropathy/plastic bronchitis population, freedom from death or transplantation after protein losing enteropathy/plastic bronchitis diagnosis at 5, 10, and 15 years was 70% (confidence interval, 58-85), 65% (confidence interval, 51-83), and 43% (confidence interval, 26-73), respectively; only older age (hazard ratio, 1.23; confidence interval, 1.01-1.52) was an independent predictor. Twenty-six surgical interventions were performed in 20 patients, comprising Fontan revisions (n = 5), fenestrations (n = 11), Fontan conversions (n = 5), atrioventricular valve repairs (n = 3), and hepatic vein diversion (n = 2).

CONCLUSIONS

Protein losing enteropathy and plastic bronchitis remain severe complications, preferably affecting patients with dominant right single ventricle, with older age at Fontan being a predictor of developing protein losing enteropathy/plastic bronchitis and poorer prognosis. Heart transplantation remains the ultimate treatment, with 30% dying or requiring transplantation within 5 years, and the remaining being stable for long periods.

An Algorithmic Approach to Minimally Invasive Management of Nontraumatic Chylothorax

Chylothorax is a rare condition characterized by lymph accumulation in the pleural space. When it occurs independent of trauma, it is even more rare and difficult to treat as identification of lymphatic leak is unpredictable. In addition, treatment of this condition with conventional lymphangiography and thoracic duct embolization may not result in positive outcomes. As such, the role of contrast-enhanced dynamic magnetic resonance lymphangiography to guide treatment is key to maximizing success with the advantage of localizing the site of lymphatic leak. Herein, we summarize etiologies of nontraumatic chylothorax, offer an updated treatment algorithm to stratify affected patients and determine appropriate treatment options, and review procedural techniques critical to efficient and effective treatment.

Nodal and Pedal MR Lymphangiography of the Central Lymphatic System: Techniques and Applications

Novel lymphatic imaging and interventional techniques are increasingly used in the diagnostic workup and treatment of pathologies of the central lymphatic system and have opened a new field of interventional radiology. The mainstay of lymphatic imaging today is magnetic resonance lymphangiography (MRL). It provides information on the anatomy of the central lymphatic system, lymphatic flow, as well as lymphatic pathologies and therefore is a valuable tool for treatment planning. There are two techniques to perform contrast-enhanced MRL: nodal dynamic contrast-enhanced MRL (nodal DCE-MRL) and interstitial transpedal MRL (tMRL). Nodal DCE-MRL yields superior information on lymphatic flow dynamics and is therefore best suited for suspected lymphatic flow pathologies and lymphatic malformations. tMRL is a technically simpler alternative for central lymphatic visualization without the need for sonographically guided lymph node cannulation. This review article describes current MRL techniques with a focus on contrast-enhanced MRL, their specific advantages, and possible clinical applications in patients suffering from pathologies of the central lymphatic system.

The Adult Patient with a Fontan

The authors summarize the most important anatomic and physiologic substrates of Fontan circulation. Common anatomic substrates include hypoplastic left heart syndrome, tricuspid atresia, double inlet left ventricle, and unbalanced atrioventricular septal defects. After the Fontan operation exercise capacity is limited and the key hemodynamic drivers is limited preload due to a relatively fixed pulmonary vascular resistance. The authors provide contemporary data on survival, morbidity, and need for reintervention. Operative morality is now expected to be less than 1% and 30 year survival approximately 89%. The authors delineate potential therapeutic approaches for the potential late complications.

Magnetic Resonance Lymphangiography

Dynamic contrast-enhanced magnetic resonance lymphangiography is a novel technique to image central conducting lymphatics. It is performed by injecting contrast into groin lymph nodes and following passage of contrast through lymphatic system using T1-weighted MR images. Currently, it has been successfully applied to image and plan treatment of thoracic duct pathologies, lymphatic leaks, and other lymphatic abnormalities such as plastic bronchitis. It is useful in the assessment of chylothorax and chyloperitoneum. Its role in other areas such as intestinal lymphangiectasia and a variety of lymphatic anomalies is likely to increase.

Pearls and Pitfalls in Pediatric Fontan Operation Imaging

The Fontan operation or the total cavopulmonary connection is a palliative surgery for single ventricle congenital heart disease where the systemic venous return circumvents a pumping chamber and flows directly into the pulmonary circuit. With surgical and medical advances, there has been improvement in life expectancy of these patients, however, it has also resulted in unique complications from the physiology that requires diligent surveillance. A critical component relies on optimal imaging for diagnosis and treatment of these complications. This article describes the normal anatomy of the Fontan circulation, current imaging modalities and techniques, and frequently encountered complications seen when imaging the patients who have undergone Fontan palliation.

Intramesenteric dynamic contrast pediatric MR lymphangiography: initial experience and comparison with intranodal and intrahepatic MR lymphangiography

OBJECTIVES

To report on our initial experience with intramesenteric (IM) dynamic contrast magnetic resonance lymphangiography (DCMRL) for evaluation of the lymphatics in patients with concern for mesenteric lymphatic flow disorders and to compare IM-DCMRL with intrahepatic (IH) and intranodal (IN) DCMRL.

METHODS

This is a retrospective review of imaging findings in 15 consecutive patients who presented with protein losing enteropathy (PLE) and/or ascites undergoing IM-DCMRL, IH-DCMRL, and IN-DCMRL. The IM-DCMRL technique involves the injection of a gadolinium contrast agent into the mesenteric lymphatic ducts or lymph nodes followed by imaging of the abdomen and chest with dynamic time-resolved MR lymphangiography.

RESULTS

IM-DCMRL was successfully performed in 14/15 (93%) of the patients. When comparing IN-DCMRL with IM-DCMRL, there was a significant difference in the visualization of dermal backflow (p = 0.014), duodenal perfusion (p = 0.003), duodenal leak (p = 0.014), and peritoneal leak (p = 0.003). IM-DCMRL demonstrated peritoneal leak in 7 patients in contrast to IH-DCMRL which demonstrated leak in 4 patients and IN-DCMRL which did not demonstrate any peritoneal leaks. Duodenal leaks were seen by IH-DCMRL in 9 patients versus 5 with IM-DCMRL and none with IN-DCMRL. In one patient with congenital PLE, the three modalities showed different disconnected flow patterns with duodenal leak only seen by IM-DCMRL. There were no short-term complications from the procedures.

CONCLUSIONS

IM-DCMRL is a feasible imaging technique for evaluation of the mesenteric lymphatics. In certain mesenteric lymphatic flow abnormalities, such as PLE and ascites, this imaging may be helpful for diagnosis and the planning of interventions and warrants further studies.

KEY POINTS

• Intramesenteric dynamic contrast magnetic resonance lymphangiography (IM-DCMRL) is a new imaging technique to evaluate mesenteric lymphatic flow disorders such as ascites. • IM-DCMRL is able to image lymphatic leaks in patients with ascites and protein losing enteropathy not seen with intranodal (IN-DCMRL) imaging.

COVID-19 in an Adult With Tricuspid Atresia S/P Fontan Palliation

In December 2019, a pathogenic novel human coronavirus (HCoV), termed SARS-CoV-2, was recognized in Wuhan, China, causing significant morbidity and mortality. The illness caused by SARS-CoV-2 is labelled coronavirus disease-2019 (COVID-19) by the World Health Organization. We report the first case of COVID-19 in an adult congenital heart disease patient with single ventricle physiology S/P Fontan palliation. (Level of Difficulty: Advanced.).

Congenital heart disease in adults (when kids grow up) pediatric geriatric anesthesia

PURPOSE OF REVIEW

The current review focuses on the new development of adult congenital heart disease (ACHD) patients in the areas of imaging, percutaneous interventions, ventricular assist devices and transplantation.

RECENT FINDINGS

Since the last ACHD publication in the journal, several advances have been made in the evaluation and treatment of these patients. As CHD patients' longevity increases pregnancy, comorbities and acquired heart disease become a concern. Recent data show that the incidence of complications in low-risk CHD is not higher that the regular population. In addition, breakthrough research in percutaneous valve implantation has been published showing good outcomes but needing intensive care recovery in a significant number of patients. In the ACHD heart failure population, assist device and transplant fields mounting evidence shows that these therapies should not be the last resort since low-risk ACHD patient may have similar outcomes to those with acquired heart disease. Finally risk stratification is important in ACHD to define better ways to recover from surgery and anesthesia.

SUMMARY

The field of anesthesia for ACHD is growing with new indications for diagnostic, interventional and surgical procedures. Tailoring cardiac and noncardiac care to the different risk profile in ACHD patients will be defined in the next few years.

VIDEO ABSTRACT

Motta summary clip: http://links.lww.com/COAN/A65.

Abnormal Pulmonary Lymphatic Flow in Patients With Lymphatic Anomalies and Respiratory Compromise

BACKGROUND

Pulmonary involvement in lymphatic anomalies (LA) is associated with significant morbidity and mortality. Dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) is capable of imaging the lymphatic system in a variety of pulmonary lymphatic disorders.

RESEARCH QUESTION

The objective of this study is to describe the central lymphatic anatomy in patients with LA and pulmonary involvement on DCMRL.

STUDY DESIGN AND METHODS

This prospective observational study enrolled 16 patients with LA (mean age, 17 years; range, 6-63 years; ratio of female to male patients, 9:7) with pulmonary involvement. All patients underwent DCMRL. The lymphatic system was assessed for the presence of mediastinal masses, interstitial lung disease, size and tortuosity of the thoracic duct (TD), and presence of abnormal pulmonary lymphatic flow.

RESULTS

T2-weighted imaging showed the following: mediastinal soft tissue masses in 10 patients, diffuse pulmonary interstitial thickening in 13 patients, and bone involvement in 15 patients. DCMRL revealed abnormal pulmonary lymphatic flow in 14 of 16 patients. Abnormal pulmonary lymphatic flow originated from the TD in three of 14 patients, the retroperitoneum in six of 14 patients, and both the TD and retroperitoneum in four of 14 patients. In nine of 16 patients, the TD was dilated and tortuous. In two patients the TD was not identified, and in five patients it was normal.

INTERPRETATION

Abnormal pulmonary lymphatic flow/perfusion from the TD or retroperitoneum into the lung parenchyma occurred in the majority of patients in this study. These findings can explain the interstitial lung disease and chylothorax resulting in deterioration of respiratory function in these patients. Future studies will determine whether mechanical cessation of this abnormal flow can improve pulmonary function and prolong survival in patients with LA.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov; No.: NCT02744027; URL: www.clinicaltrials.gov.

Back to the Future: Lipiodol in Lymphography-From Diagnostics to Theranostics

Lipiodol is an iodinated poppy seed oil first synthesized in 1901. Originally developed for therapeutic purposes, it has mainly become a diagnostic contrast medium since the 1920s. At the end of the 20th century, Lipiodol underwent a transition back to a therapeutic agent, as exemplified by its increasing use in lymphangiography and lymphatic interventions. Nowadays, indications for lymphangiography include chylothorax, chylous ascites, chyluria, and peripheral lymphatic fistula or lymphoceles. In these indications, Lipiodol alone has a therapeutic effect with clinical success in 51% to 100% of cases. The 2 main access sites to the lymphatic system for lymphangiography are cannulation of lymphatic vessels in the foot (transpedal) and direct puncture of (mainly inguinal) lymph nodes (transnodal). In case of failure of lymphangiography alone to occlude the leaking lymphatic vessel as well as in indications such as protein-losing enteropathy, postoperative hepatic lymphorrhea, or plastic bronchitis, lymphatic vessels can also be embolized directly by injecting a mixture of Lipiodol and surgical glues (most commonly in thoracic duct embolization). The aim of this article is to review the historical role of Lipiodol and the evolution of its clinical application in lymphangiography over time until the current state-of-the-art lymphatic imaging techniques and interventions.

Single-Ventricle Physiology

Single-ventricle physiology occurs in patients with hypoplastic ventricular heart defects, either on the right or left, who have undergone stepwise palliation surgeries ending with the Fontan procedure. After Fontan completion, these patients are dependent on passive venous return to the pulmonary circulation. The implications of passive flow are potentially devastating to the patient. We discuss some of the basic changes to the patient’s experience after a Fontan procedure, as well as the common complications. We also touch on some of the emerging management strategies for the common complications.

Airway emergency during general anesthesia in a child with plastic bronchitis following Fontan surgery: a case report

Background

Plastic bronchitis (PB) is a complication of Fontan surgery, results in the formation of mucus plug in the tracheobronchial tree, causing potentially fatal airway obstruction. We report critical airway emergency during general anesthesia in a child with plastic bronchitis.

Case presentation

A 5-year-old boy was scheduled for intrapulmonary lymphatic embolization through percutaneous catheterization under general anesthesia. He underwent Fontan surgery at the age of 2 and frequently developed respiratory failure due to plastic bronchitis. After induction of general anesthesia and tracheal intubation, mechanical ventilation became difficult even with an inspiratory pressure ≥ 50 mmHg due to airway obstruction. He expectorated a large mucus plug through the tracheal tube after administration of sugammadex, naloxone, and flumazenil, and respiratory condition was stabilized thereafter.

Conclusion

General anesthesia for a patient with plastic bronchitis should be planned with extracorporeal membrane oxygenation or cardiopulmonary bypass stand by.

Case Report: Disseminated Systemic Embolism of Lipiodol After Lymphography for Plastic Bronchitis After Fontan Repair

Lipiodol-based lymphangiography is not only a diagnostic tool for visualization of lymphatic disorders such as plastic bronchitis (PB), but also aims a therapeutic effect by embolizing lymph leakages. We performed such percutaneous lymphatic embolization for PB in a Fontan patient with proven absence of right-to-left shunt, and demonstrated important lymphatic abnormalities in the mediastinum. Shortly after the procedure, the patient developed severe convulsive seizures, revealing multiple cerebral embolisms of Lipiodol. Radiological images were impressive, yet the clinical neurological outcome was favorable. Lipiodol-based lymphography in Fontan patients with plastic bronchitis should be avoided as this subgroup is more likely to have developed lympho-pulmonary venous connections which allow systemic emboli.

Protein Losing Enteropathy After Fontan Operation: Glimpses of Clarity Through the Lifting Fog

Fontan-associated protein losing enteropathy is a challenge to treat and is a major contributor to morbidity and mortality in patients with palliated single ventricle. Numerous strategies for management have been proposed, with confusion as to how best to stratify and implement care among the many treatments available. Medical management can be helpful in some, while novel lymphatic interventions hold potential for remission with good results. We review our institutional approach to protein losing enteropathy after Fontan operation and provide a suggested algorithm and pathway for effective care.