Cerebral Lipiodol Embolism after Lymphatic Embolization for Plastic Bronchitis

Interventional solutions for post-surgical problems: a lymphatic leaks review

The lymphatic circulation plays a crucial role in maintaining fluid balance and supporting immune responses by returning serum proteins and lipids to the systemic circulation. Lymphatic leaks, though rare, pose significant challenges post-radical neck surgery, oesophagectomy, and thoracic or retroperitoneal oncological resections, leading to heightened morbidity and mortality. Managing lymphatic leaks necessitates consideration of aetiology, severity, and volume of leakage. Traditionally, treatment involved conservative measures such as dietary restrictions, drainage, and medical management, with surgical intervention reserved for severe cases, albeit with variable outcomes and extended recovery periods. Lymphography, introduced in the 1950s, initially served as a diagnostic tool for lymphoedema, lymphoma, tumour staging, and monitoring chemotherapy response. However, its widespread adoption was impeded by alternative techniques like Computed Tomography, learning curves, and its associated complications. Contemporary lymphatic interventions have evolved, favouring nodal lymphangiography over pedal lymphangiography for its technical simplicity and reduced complexity. Effective management of chylous leaks mandates a multimodal approach encompassing clinical evaluation and imaging techniques. In cases where conservative management proves ineffective, embolization through conventional lymphangiography by bipedal dissection or intranodal injection emerges as a viable option. This review underscores the importance of a comprehensive approach to diagnosing and treating lymphatic leaks, highlighting advancements in imaging and therapeutic interventions that enhance patient outcomes.

Mycoplasma pneumoniae pneumonia-associated thromboembolism with plastic bronchitis: a series of five case reports and literature review

BACKGROUND

Mycoplasma pneumoniae pneumonia is a common respiratory infection among children. However, the occurrence of thromboembolism with plastic bronchitis in association with Mycoplasma pneumoniae pneumonia is extremely rare. This case series presents five cases of children with Mycoplasma pneumoniae pneumonia who developed thromboembolism and plastic bronchitis. The clinical presentation, diagnostic approach, and management strategies are discussed.

METHODS

A retrospective analysis was conducted on medical records from a pediatric hospital. Patient demographics, clinical features, laboratory findings, imaging results, treatment modalities, and outcomes were collected.

RESULTS

The patients in our case series presented with varying degrees of respiratory distress, cough, and fever. Imaging studies revealed evidence of thromboembolism based on pulmonary artery occlusion. Bronchial casts were observed by bronchoscopy. Laboratory tests demonstrated elevated D-dimer levels and fibrinogen degradation products. All patients received a combination of low molecular weight heparin anticoagulation and supportive care.

CONCLUSION

Thromboembolism with plastic bronchitis associated with Mycoplasma pneumoniae pneumonia is a rare but potentially serious complication in children. Prompt recognition and management are crucial for improving patient outcomes. This case series highlights the diverse clinical presentations, diagnostic challenges, and treatment strategies for this unique clinical entity. Further research is needed to better understand the pathogenesis and optimal management of this condition.

MR Lymphangiography in Lymphatic Disorders: Clinical Applications, Institutional Experience, and Practice Development

Lymphatic flow and anatomy can be challenging to study, owing to variable lymphatic anatomy in patients with diverse primary or secondary lymphatic pathologic conditions and the fact that lymphatic imaging is rarely performed in healthy individuals. The primary components of the lymphatic system outside the head and neck are the peripheral, retroperitoneal, mesenteric, hepatic, and pulmonary lymphatic systems and the thoracic duct. Multiple techniques have been developed for imaging components of the lymphatic system over the past century, with trade-offs in spatial, temporal, and contrast resolution; invasiveness; exposure to ionizing radiation; and the ability to obtain information on dynamic lymphatic flow. More recently, dynamic contrast-enhanced (DCE) MR lymphangiography (MRL) has emerged as a valuable tool for imaging both lymphatic flow and anatomy in a variety of congenital and acquired primary or secondary lymphatic disorders. The authors provide a brief overview of lymphatic physiology, anatomy, and imaging techniques. Next, an overview of DCE MRL and the development of an MRL practice and workflow in a hybrid interventional MRI suite incorporating cart-based in-room US is provided, with an emphasis on multidisciplinary collaboration. The spectrum of congenital and acquired lymphatic disorders encountered early in an MRL practice is provided, with emphasis on the diversity of imaging findings and how DCE MRL can aid in diagnosis and treatment of these patients. Methods such as DCE MRL for assessing the hepatic and mesenteric lymphatic systems and emerging technologies that may further expand DCE MRL use such as three-dimensional printing are introduced. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Lymphatic Imaging and Intervention in Congenital Heart Disease

The lymphatic system plays a central role in some of the most devastating complications associated with congenital heart defects. Diseases like protein-losing enteropathy, plastic bronchitis, postoperative chylothorax, and chylous ascites are now proven to be lymphatic in origin. Novel imaging modalities, most notably, noncontrast magnetic resonance lymphangiography and dynamic contrast-enhanced magnetic resonance lymphangiography, can now depict lymphatic anatomy and function in all major lymphatic compartments and are essential for modern therapy planning. Based on the new pathophysiologic understanding of lymphatic flow disorders, innovative minimally invasive procedures have been invented during the last few years with promising results. Abnormal lymphatic flow can now be redirected with catheter-based interventions like thoracic duct embolization, selective lymphatic duct embolization, and liver lymphatic embolization. Lymphatic drainage can be improved through surgical or interventional techniques such as thoracic duct decompression or lympho-venous anastomosis.

Imaging and Interventions for Lymphatic and Lymphatic-related Disorders

The lymphatic system is critical in fluid balance homeostasis. Yet, until recently, lymphatic imaging has been outside of mainstream medicine due to a lack of robust imaging and interventional options. However, during the last 20 years, both clinical lymphatic imaging and interventions have shown dramatic advancement. The key to imaging advancement has been the interstitial delivery of contrast agents through lymphatic-rich tissues. These techniques include intranodal lymphangiography and dynamic contrast-enhanced MR lymphangiography. These methods provide the ability to image and recognize lymphatic anatomy and pathologic conditions. Percutaneous thoracic duct catheterization and embolization became the first widely accepted interventional technique for the management of chyle leaks. Advances in interstitial lymphatic embolization, as well as liver and mesenteric lymphatic interventions, have broadened the scope of possible lymphatic interventions. Also, recent techniques of lymphatic decompression allow for the treatment of a variety of lymphatic disorders. Finally, immunologic studies of central lymphatic fluid reveal the potential of lymphatic interventions on immunity. These advances herald an exciting new chapter for lymphatic imaging and interventions in the coming years.

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.

Imaging Findings of Thoracic Lymphatic Abnormalities

The lymphatic system plays an important role in balancing fluid compartments in the body. It is disrupted by various disease processes in the thorax, including injury to the thoracic lymphatic duct after surgery, as well as malignancy and heart failure. Because of the small size of lymphatic vessels, imaging of the lymphatics is relatively difficult, and effective imaging methods are still being optimized and developed. The standard of reference for lymphatic imaging has been conventional lymphangiography for several decades. Other modalities such as CT, noncontrast or contrast-enhanced MRI, and lymphoscintigraphy can also demonstrate lymphatic abnormalities and help in treatment planning. Imaging findings associated with lymphatic abnormalities can be seen in the pulmonary parenchyma, pleural space, and mediastinum. In the pulmonary parenchyma, common findings include interlobular septal thickening as well as reversal of lymphatic flow with intravasation of contrast material into pulmonary lymphatics. In the pleural space, findings include chylous pleural effusion and occasionally nonchylous pleural effusion. In the mediastinum, thoracic duct leak, plexiform thoracic duct, lymphatic malformations, and lymphangiectasis may occur. Management of chylothorax includes conservative or medical treatment, surgery, and interventional radiology procedures. The authors discuss thoracic lymphatic anatomy, imaging manifestations of lymphatic abnormalities in the various anatomic compartments, and interventional radiology treatment of chylothorax. Radiologists should be familiar with these imaging findings for diagnosis and to help guide appropriate management. ^©RSNA, 2022.

Clinical Uses and Short-Term Safety Profile of Ethiodized Poppy Seed Oil Contrast Agent in the Diagnosis and Treatment of Vascular Anomalies and Tumors

Background: There is a sparsity of data on the use of ethiodized poppy seed oil (EPO) contrast agent (Lipiodol) in patients. We investigated the safety of EPO in children, adolescents, and some adults for diagnostic and therapeutic interventions. Methods: All patients who underwent procedures with EPO between 1995 and 2014 were retrospectively included. Demographic characteristics, diagnosis, dose, route of administration, preparation of EPO in combination with other agents, and complications were recorded. Results: In 1422 procedures, EPO was used for diagnostic or treatment purposes performed in 683 patients. The mean patient age was 13.4 years (range: 2 months–50 years); 58% of patients were female. Venous malformations (n = 402, 58.9%) and arteriovenous malformations (n = 60, 8.8%) were the most common diagnosis. Combined vascular anomalies included capillary–lymphatic–venous malformations, fibroadipose vascular anomalies (n = 54, 7.9%), central conducting lymphatic anomalies (n = 31, 4.5%), lymphatic malformations (n = 24, 3.5%), aneurysmal bone cysts (n = 22, 3.2%), and vascularized tumors (n = 11, 1.6%). In 1384 procedures (96%), EPO was used in various combinations with sclerosing and embolization agents, including sodium tetradecyl sulfate, ethanol, and glue. The mean volume of EPO used in interventions was 3.85 mL (range: 0.1–25 mL) per procedure with a mean patient weight of 45.9 kg (range: 3.7–122.6 kg) and a weight-adjusted dose of 0.12 mL/kg (range: 0.001–1.73 mL/kg). In 56 procedures (4%), EPO was used as a single agent for diagnostic lymphangiography. The mean volume was 4.8 mL (range: 0.3–13 mL) per procedure with a mean patient weight of 27.4 kg (range: 2.4–79.3 kg) and a weight-adjusted dose of 0.2 mL/kg (range: 0.04–0.54 mL/kg). Procedural-related complications occurred in 25 (1.8%) procedures. The 20 minor and 5 major complications were related to the primary treatment agents. None of them were directly related to EPO. No allergic reactions were noted. Conclusion: The use of an ethiodized poppy seed oil contrast agent in children, adolescents, and adults for diagnostic or therapeutic purposes is safe.

Cerebral lipiodol embolisation

Cerebral lipiodol embolisation is a rare but serious complication of lymphangiography. A man in his seventies had undergone lymphangiography for a refractory chyle leak following oesophagectomy. The day after lymphangiography, his conscious level dropped with bilaterally miotic pupils, increased muscle tone and double incontinence. CT scan of the head showed patchy high density throughout basal ganglia, cortex and cerebellum but no infarct, in keeping with lipiodol embolisation. He was managed initially in intensive care and subsequently underwent thoracoscopy with clipping and suturing of the left thoracic duct, and later a talc pleurodesis. At 3 months, he had some cognitive limitations and was walking with a stick.

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.

Direct EBUS-guided transtracheal lymphosclerosis for plastic bronchitis after Fontan

We report on a new puncture technique with direct transtracheal mediastinal lymphatic access to treat plastic bronchitis after Fontan repair. High resolution contrast-enhanced spiral CT identified enlarged lymph nodes in the paratracheal region. Inguinal intranodal Gadolinium Dynamic Contrast-enhanced Magnetic Resonance lymphangiography (DCMRL) confirmed the pathologic centrifugal lymph flow passing through these lymph nodes before leaking into the bronchial tree. The abnormal hypertrophic paratracheal, subcarinal, and hilar lymph nodes were punctured with a 22G needle through an endobronchial ultrasound bronchoscope. Occlusion of the lymph vessels was obtained by injecting a mixture of lipiodol/NBCA N-butyl cyanoacrylate (Histoacryl) 5/1 under fluoroscopic control. There was a total remission of PB with now 10 months of follow-up.

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.

Complications during Lymphangiography and Lymphatic Interventions

Lymphangiography as a diagnostic procedure dates back to the 1950s and was widely performed for several decades until being supplanted by other advanced imaging techniques. With the advent of thoracic duct embolization to treat chylothorax, Constantin Cope ushered in a transition from lymphangiography as a diagnostic procedure to a precursor for lymphatic intervention. Subsequently, technical modifications and applications of lymphatic embolization to other medical conditions have greatly expanded the scope and application of lymphangiography and lymphatic intervention. Although there is increasing familiarity with lymphatic interventions, few interventionalists have performed a high enough volume to be aware of potential complications and their management. Potential complications of lymphangiography and those encountered while performing lymphatic interventions are discussed along with approaches to minimize their risk and management strategies should they occur.

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.

Comparison of radiopaque dye materials for localization of pulmonary nodules before video-assisted thoracic surgery

Background

Although a mixture of pigments and radiopaque materials was reported to be useful material for lung nodule localization, the optimal combination has not been well investigated. The purpose of this study is to evaluate the characteristics of various combinations of pigments and radiopaque materials for localization of pulmonary nodules prior to video-assisted thoracic surgery (VATS).

Methods

We compared stability, viscosity, and visibility of 6 radiopaque dye materials of (I) mixture of indigo carmine and lipiodol; (II) mixture of indigo carmine, lipiodol, and lidocaine gel; (III) mixture of indocyanine green in water solution (w-ICG) and lipiodol; (IV) mixture of w-ICG, lipiodol, and lidocaine gel; (V) ICG in contrast medium solution (cm-ICG); and (VI) mixture of cm-ICG and lidocaine gel. Stability was evaluated by observing changes in the mixtures in the test tube with time visually and radiographically. Viscosities were measured by rotational viscometer. Materials were injected into an expanded pig-lung phantom, and area on CT and visibility on thoracoscopy camera were evaluated.

Results

Separation could be seen 15 min after preparation in (I) and (III), and 1 h after preparation in (II), both visually and radiographically. In (IV), separation could be seen on the photographs but not on the X-ray images from 3 h after preparation. (V) and (VI) showed no changes within the 2-day observation period. The viscosities of the materials were (I) 0.2±0.1, (II) 2.9±0.1, (III) 0.2±0.1, (IV) 2.6±0.1, (V) 0.2±0.1, and (VI) 1.2±0.1 dPa·s. The area on CT showed very strong negative correlation with viscosity (r=−0.97). The injection point of each material was easily detected on thoracoscopy camera.

Conclusions

Radiopaque dye materials appear useful for localizing pulmonary nodules before VATS; their diffusion in the lung parenchyma can be suppressed by using materials of high viscosity.

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.

Devastating cerebral Lipiodol® embolization related to therapeutic lymphangiography for refractory chylothorax in a patient with Behçet’s disease

Abstract. Onset of neurological symptoms early after intranodal lymphangiography can occur due to Lipiodol droplet migration through intrapulmonary lymphovenous communication. Patients with Behçet’s disease may be at higher risk of developing this devastating complication.

Lymphatic imaging and intervention in a pediatric population: Anesthetic considerations

The recent adoption of an improved lymphatic access technique coupled with Dynamic Contrast-enhanced Magnetic Resonance Lymphangiography has introduced the ability to diagnose and treat severe lymphatic disorders unresponsive to other therapies. All pediatric patients presenting for lymphatic procedures require general anesthesia presenting challenges in managing highly morbid and comorbid conditions both from logistical as well as medical aspects. General anesthesia is used because of the procedural requirement for immobility to accurately place needles and catheters, treat pain secondary to contrast and glue injections, and to accommodate additional procedures. We reviewed a one-year cohort of all pediatric patients in a newly created Center for Lymphatic Imaging and Intervention at a tertiary care children's hospital presenting for lymphatic procedures. The patients ranged in age from 4 days to 17 years and weighed from 2.5 to 92 kg. There were 106 anesthetics for 68 patients. Patients were functionally impaired (98% ASA 3 or 4) and included significant comorbidities (79.4%). Concurrent with lymphatic imaging and intervention additional procedures were frequently performed (76%). They included cardiac catheterization, bronchoscopy, endoscopy, and drain placement (thoracic or abdominal). Paralysis and controlled ventilation was used for all interventions. Reversal of paralysis and tracheal extubation occurred in all patients not previously managed by invasive respiratory support. All patients having an intervention were admitted to intensive care for observation where escalation of care or complications (fever, hypotension, bleeding, or stroke) occurred in 25% in the first 24 hours.

Ultradense Middle Cerebral Artery: Specific Sign of Cerebral Lipiodol Embolization

Cerebral lipiodol embolization is a rare but known complication of lymphatic embolization for plastic bronchitis. The classic imaging finding on a noncontrast head computed tomography is multiple small areas of hyperdensity within the cerebral hemispheres, which represent lipiodol deposition in the brain. We report a case of lipiodol deposition in the middle cerebral artery following lymphatic embolization, producing an "ultradense" vessel sign on noncontrast computed tomography.