Interventional radiology in the management of thoracic duct injuries: Anatomy, techniques and results

Meningeal lymphatic drainage: novel insights into central nervous system disease

In recent years, increasing evidence has suggested that meningeal lymphatic drainage plays a significant role in central nervous system (CNS) diseases. Studies have indicated that CNS diseases and conditions associated with meningeal lymphatic drainage dysfunction include neurodegenerative diseases, stroke, infections, traumatic brain injury, tumors, functional cranial disorders, and hydrocephalus. However, the understanding of the regulatory and damage mechanisms of meningeal lymphatics under physiological and pathological conditions is currently limited. Given the importance of a profound understanding of the interplay between meningeal lymphatic drainage and CNS diseases, this review covers seven key aspects: the development and structure of meningeal lymphatic vessels, methods for observing meningeal lymphatics, the function of meningeal lymphatics, the molecular mechanisms of meningeal lymphatic injury, the relationships between meningeal lymphatic vessels and CNS diseases, potential regulatory mechanisms of meningeal lymphatics, and conclusions and outstanding questions. We will explore the relationship between the development, structure, and function of meningeal lymphatics, review current methods for observing meningeal lymphatic vessels in both animal models and humans, and identify unresolved key points in meningeal lymphatic research. The aim of this review is to provide new directions for future research and therapeutic strategies targeting meningeal lymphatics by critically analyzing recent advancements in the field, identifying gaps in current knowledge, and proposing innovative approaches to address these gaps.

Chylothorax in thoracic oncology: diagnostic challenges and management strategies

Chylothorax is a distinctive form of pleural effusion characterized by the accumulation of chyle within the pleural space. We conducted an analysis of published evidence concerning oncological chylothorax, encompassing complications following thoracic surgery or spontaneous occurrences directly linked to thoracic malignancies. Diagnosis can be established based on clinical features of the pleural effusion and through analysis of pleural fluid. The presence of chylomicrons, measured by lipoprotein electrophoresis, triglyceride levels, and cholesterol content are indicative factors. In cases of spontaneous chylothorax, the identification of pleural effusion on CT scans showing suspicious oncological masses, such as lymphomas, prompts pleural drainage for confirmation of chylothorax. Conversely, post-surgical chylothorax diagnoses are immediate due to the pre-existing pleural drainage. In our last 10 years of experience, we have had only 18 cases of chylothorax: 28% underwent successful redo-surgery and 72% were conservatively treated. All the patients recovered well, and none experienced life-threatening situations. Conservative approaches involve hypo/alipidic diets, total parenteral nutrition, and pharmacological interventions. In persistent and challenging cases of chylothorax where drainage output is excessive, redo-surgery is recommended.

Application of ultrasound-guided intranodal lymphangiography in the diagnosis and treatment of chylous ascites after abdominal surgery

Purpose

Chylous leakage is a serious and challenging postoperative complication. The purpose of this study was to explore the application of ultrasound-guided intranodal lymphangiography in the diagnosis and treatment of chylous ascites following abdominal surgery.

Material and methods

Ten patients with chylous ascites after abdominal surgery after ineffective conservative treatment such as low-fat diet, parenteral nutrition, and negative pressure drainage were included in this single-center retrospective study. Of these 10 patients, 9 developed chylous ascites after liver surgery, and 1 after a radical gastrectomy.

Results

Lymphangiography was successfully performed in all 10 patients. The average dosage of lipiodol used was 4.5 ml (range 3.5-7.0 ml). No procedure-related complications were observed after excluding unrelated factors. During lymphangiography, lipiodol leakage was directly observed in 3 cases, and in the other 5 cases, it was detected through abdominal computed tomography post-lymphangiography. Chylous ascites resolved solely through lymphangiography in 6 patients without requiring additional surgical intervention.

Conclusions

Lymphangiography may help identify leakage sites in patients with chylous ascites unresponsive to conservative treatment and could potentially be effective in treating chylous ascites following abdominal surgery.

Thoracic Duct Visualization in Esophageal Resection: A Pilot Trial

INTRODUCTION

Inadvertent thoracic duct injury is common during esophagectomy and may result in postoperative chylothorax. This study's objective was to investigate utility of patent blue injection as a modality for intraoperative thoracic duct visualization.

METHODS

A prospective, single-arm, interventional study of patients undergoing minimally invasive esophagectomy was performed. Patients were injected with patent blue dye into both groins prior to thoracic stage of surgery and assessed for duct visualization. Control group was formed by propensity score matching using retrospectively collected data regarding patients who underwent esophagectomy.

RESULTS

A total of 25 patients were included in analysis, compared to a control of 50 patients after matching. Thoracic duct was visualized in 60% of patients in the study group (15/25 patients). Significant differences were found between study and control groups (p < 0.05) with regards to median operative time (422 vs. 285 min, respectively), overall complications (16 vs. 34%, respectively), and median postoperative length of stay (13.5 vs. 10 days, respectively). There was a difference in rate of chyle leak between study and control groups; however, this was not significant (0 vs. 12%, respectively, p = 0.17).

CONCLUSION

Patent blue injection represents a simple method for thoracic duct visualization during minimally invasive esophagectomy which may improve surgical outcomes.

[Chylothorax]

Chylothorax is a serious and potentially life-threatening condition of diverse etiology. This article provides a detailed overview of anatomy, physiology, etiology, diagnosis, and therapeutic options in the context of chylothorax.

Back to the Future II-A Comprehensive Update on the Rapidly Evolving Field of Lymphatic Imaging and Interventions

ABSTRACT

Lymphatic imaging and interventional therapies of disorders affecting the lymphatic vascular system have evolved rapidly in recent years. Although x-ray lymphangiography had been all but replaced by the advent of cross-sectional imaging and the scientific focus shifted to lymph node imaging (eg, for detection of metastatic disease), interest in lymph vessel imaging was rekindled by the introduction of lymphatic interventional treatments in the late 1990s. Although x-ray lymphangiography is still the mainstay imaging technique to guide interventional procedures, several other, often less invasive, techniques have been developed more recently to evaluate the lymphatic vascular system and associated pathologies. Especially the introduction of magnetic resonance, and even more recently computed tomography, lymphangiography with water-soluble iodinated contrast agent has furthered our understanding of complex pathophysiological backgrounds of lymphatic diseases. This has led to an improvement of treatment approaches, especially of nontraumatic disorders caused by lymphatic flow abnormalities including plastic bronchitis, protein-losing enteropathy, and nontraumatic chylolymphatic leakages. The therapeutic armamentarium has also constantly grown and diversified in recent years with the introduction of more complex catheter-based and interstitial embolization techniques, lymph vessel stenting, lymphovenous anastomoses, as well as (targeted) medical treatment options. The aim of this article is to review the relevant spectrum of lymphatic disorders with currently available radiological imaging and interventional techniques, as well as the application of these methods in specific, individual clinical situations.

Chylothorax and chylous ascites: Overview, management, and nutrition

Chyle leaks of any source or type can cause significant morbidity and mortality. Attention to the anatomy and physiology of the leak, followed by stepwise dietary and pharmacologic management, obviates the need for surgical intervention in a majority of patients. In this article, we review the importance, etiology, anatomy, diagnosis, nutrition and immunologic effects, and options for treatment of chylothorax and chylous ascites based on experience and prior literature. We propose a multidisciplinary approach to optimize these treatments including the primary surgical teams, pharmacists, and dietitians, with reoperation as a last resort to minimize the morbidity of this challenging complication.

Multidisciplinary Management of Chylothorax

Chylothorax, the accumulation of chyle in the pleural space, is usually caused by the disruption of the thoracic duct or its tributaries. Etiologies are broadly divided into traumatic, including postsurgical, and nontraumatic, most commonly in the setting of malignancy. The management of chylothorax largely depends on the cause and includes dietary modification and drainage of the pleural space. A definitive intervention, whether surgical or a percutaneous lymphatic intervention, should be considered in patients with a persistently high volume of chylous output and in those with a prolonged leak, before complications such as malnutrition ensue. No methodologically robust clinical trials guiding management are currently available. In this article, we review the current literature and propose a stepwise, evidence-based multidisciplinary approach to the management of patients with both traumatic and nontraumatic chylothorax.

Interventional Management of Acquired Lymphatic Disorders

The lymphatic system is a complex network of tissues, vessels, and channels found throughout the body that assists in fluid balance and immunologic function. When the lymphatic system is disrupted related to idiopathic, iatrogenic, or traumatic disorders, lymphatic leaks can result in substantial morbidity and/or mortality. The diagnosis and management of these leaks is challenging. Modern advances in lymphatic imaging and interventional techniques have made radiology critical in the multidisciplinary management of these disorders. The authors provide a review of conventional and clinically relevant variant lymphatic anatomy and recent advances in diagnostic techniques such as MR lymphangiography. A detailed summary of technical factors related to percutaneous lymphangiography and lymphatic intervention is presented, including transpedal and transnodal lymphangiography. Traditional transabdominal access and retrograde access to the central lymph nodes and thoracic duct embolization techniques are outlined. Newer techniques including transhepatic lymphangiography and thoracic duct stent placement are also detailed. For both diagnostic and interventional radiologists, an understanding of lymphatic anatomy and modern diagnostic and interventional techniques is vital to the appropriate treatment of patients with acquired lymphatic disorders. ^©RSNA, 2022.

Understanding Lymphatic Anatomy and Abnormalities at Imaging

Lymphatic abnormalities encompass a wide range of disorders spanning solitary common cystic lymphatic malformations (LMs) to entities involving multiple organ systems such as lymphangioleiomyomatosis. Many of these disorders are rare, yet some, such as secondary lymphedema from the treatment of malignancy (radiation therapy and/or lymph node dissection), affect millions of patients worldwide. Owing to complex and variable anatomy, the lymphatics are not as well understood as other organ systems. Further complicating this is the variability in the description of lymphatic disease processes and their nomenclature in the medical literature. In recent years, medical imaging has begun to facilitate a deeper understanding of the physiology and pathologic processes that involve the lymphatic system. Radiology is playing an important and growing role in the diagnosis and treatment of many lymphatic conditions. The authors describe both normal and common variant lymphatic anatomy. Various imaging modalities including nuclear medicine lymphoscintigraphy, conventional lymphangiography, and MR lymphangiography used in the diagnosis and treatment of lymphatic disorders are highlighted. The authors discuss imaging many of the common and uncommon lymphatic disorders, including primary LMs described by the International Society for the Study of Vascular Anomalies 2018 classification system (microcystic, mixed, and macrocystic LMs; primary lymphedema). Secondary central lymphatic disorders are also detailed, including secondary lymphedema and chylous leaks, as well as lymphatic disorders not otherwise easily classified. The authors aim to provide the reader with an overview of the anatomy, pathology, imaging findings, and treatment of a wide variety of lymphatic conditions. ^©RSNA, 2022.

Using aneurysm clips for repair of cisterna chyli injury during posterior spinal fusion

Background:

Injury to the cisterna chyli (CC) is a rare surgical complication with a lack of literature describing its repair. Aneurysm clips have been successfully used to repair durotomies. Its usage in lymphatic injury has never been described. We sought to demonstrate the use of aneurysm clips for the repair of lymphatic vessels.

Case Description:

A 60-year-old male retired physician with Parkinson’s disease underwent a lumbosacral instrumented fusion with pelvic fixation (L1-pelvis) in 2011. He returned 5 months postoperatively after a fall and was ambulatory with a cane upon admission. CT demonstrated worsening kyphosis with pedicular and superior endplate fracture at the fusion apex. MRI revealed spinal cord compression at the failed level. Extension thoracolumbar fusion was performed (T3-L1) with intraoperative violation of the anterior longitudinal ligament (ALL) during T12/L1 discectomy. CC laceration was suspected. The ALL was dissected from the CC and aorta, allowing visualization of the injury. Three curved aneurysm clips were applied to the lacerated CC, which was visually inspected to ensure a patent lumen. The disk space was filled with poly-methyl-methacrylate cement in place of an interbody cage, preventing migration of the clips. The patient underwent rehabilitation in an inpatient facility with improved ambulation. He has had regular clinic follow-up and was last seen in 2020 with no evidence of lymphedema noted.

Conclusion:

CC injury is rare, and usage of aneurysm clips in its repair has never been described. We demonstrate the safe use of aneurysm clips to repair CC injury with long-term favorable clinical outcomes.

Physiological models for in vivo imaging and targeting the lymphatic system: Nanoparticles and extracellular vesicles

Imaging of the lymphatic vasculature has gained great attention in various fields, not only because lymphatic vessels act as a key draining system in the body, but also for their implication in autoimmune diseases, organ transplant, inflammation and cancer. Thus, neolymphangiogenesis, or the generation of new lymphatics, is typically an early event in the development of multiple tumor types, particularly in aggressive ones such as malignant melanoma. Still, the understanding of how lymphatic endothelial cells get activated at distal (pre)metastatic niches and their impact on therapy is still unclear. Addressing these questions is of particular interest in the case of immune modulators, because endothelial cells may favor or halt inflammatory processes depending on the cellular context. Therefore, there is great interest in visualizing the lymphatic vasculature in vivo. Here, we review imaging tools and mouse models used to analyze the lymphatic vasculature during tumor progression. We also discuss therapeutic approaches based on nanomedicines to target the lymphatic system and the potential use of extracellular vesicles to track and target sentinel lymph nodes. Finally, we summarize main pre-clinical models developed to visualize the lymphatic vasculature in vivo, discussing their applications with a particular focus in metastatic melanoma.

Chylothorax as a complication of Waldenström macroglobulinaemia with a patient's perspective

Chylothorax has rarely been reported as a pleuropulmonary complication of Waldenström macroglobulinaemia (WM). In general, when a unilateral effusion is discovered particularly in patients with a history of cancer or active malignancy, a broad differential including chylothorax needs to be considered. We present the case of a 50-year-old woman found to have chylothorax secondary to progression of WM as confirmed by cytology and presence of MYD88 L265P mutation in the pleural fluid specimen and subsequent resolution with chemotherapy. This review centres particularly on non-traumatic causes of chylothorax with a focus on WM and includes a unique patient perspective.

Imaging technology of the lymphatic system

The lymphatic system plays critical roles in tissue fluid homeostasis and immunity and has been implicated in the development of many different pathologies, ranging from lymphedema, the spread of cancer to chronic inflammation. In this review, we first summarize the state-of-the-art of lymphatic imaging in the clinic and the advantages and disadvantages of these existing techniques. We then detail recent progress on imaging technology, including advancements in tracer design and injection methods, that have allowed visualization of lymphatic vessels with excellent spatial and temporal resolution in preclinical models. Finally, we describe the different approaches to quantifying lymphatic function that are being developed and discuss some emerging topics for lymphatic imaging in the clinic. Continued advancements in lymphatic imaging technology will be critical for the optimization of diagnostic methods for lymphatic disorders and the evaluation of novel therapies targeting the lymphatic system.

Chylothorax - Modalities of management and outcomes: A case series

Background:

At present, there are no universally accepted protocols for the management of chylothorax. This study aims at reporting the clinical experience and presenting our institutional protocol for managing chylothorax.

Materials and Methods:

This is a retrospective analysis of chylothorax patients managed at a dedicated thoracic surgical unit over 8 years. A detailed analysis of demography and perioperative variables including complications was carried out. Factors influencing failure of conservative and surgical therapy were analyzed.

Results:

A total of 26 patients were included with a mean age of 42.4 years (range, 2–72 years). Postsurgical chylothorax was the most common variant (53.8%). Majority (46.1%) of the patients had >1000 ml/24 h intercostal tube drainage at presentation. All patients were initially subjected to conservative management, of which 11 (42.4%) patients were managed successfully with conservative therapy alone. Rest 15 (57.6%) patients required video-assisted thoracoscopic thoracic duct ligation, which was successful in 10/15 (66.7%) patients, whereas additional intervention was required in 5/15 (33.3%) patients. Drain output of >1000 ml/day was an independent predictor of failure of conservative therapy. Nontraumatic bilateral chylothorax was associated with high probability of failure of surgical therapy in the first attempt and may require additional treatment modality.

Conclusions:

Initial conservative management is recommended for all chylothorax patients, which is unlikely to succeed if daily drainage is >1000 ml/24 h. VATS thoracic duct ligation is recommended in such cases. Nontraumatic bilateral chylothorax has higher surgical failure rates. In such cases, additional procedures in the form of pleurodesis and/or thoracic duct embolization/disruption should be considered.

Chyle Leakage after Esophageal Cancer Surgery

Surgeons recommend dissecting lymph nodes in the thorax, abdomen, and neck during surgery for esophageal cancer because of the possibility of metastasis to the lymph nodes in those areas through the lymphatic plexus of the esophageal submucosal layer. Extensive lymph node dissection is essential for accurate staging and is thought to improve survival. However, it can result in several complications, including chyle leakage, which refers to continuous lymphatic fluid leakage and can occur in the thorax, abdomen, and neck. Malnutrition, fluid imbalance, and immune compromise may result from chyle leakage, which can be potentially life-threatening if it persists. Therefore, various treatment methods, including conservative treatment, pharmacological treatment such as octreotide infusion, and interventions such as thoracic duct embolization and surgical thoracic duct ligation, have been applied. In this article, the risk factors, diagnosis, and treatment methods of chyle leakage after esophagectomy are reviewed.

Combined antegrade and retrograde thoracic duct embolization for complete transection of the thoracic duct

Chylothorax is an uncommon complication after thoracoabdominal surgery and is typically due to injury of the thoracic duct (TD) or one of its tributaries. Patients who fail conservative management benefit from thoracic duct embolization (TDE). TDE is a percutaneous technique that includes pedal or intranodal lymphangiography, transabdominal catheterization of the TD, and glue embolization of the TD. Alternative access to the TD can be achieved via retrograde transvenous approach or direct US-guided puncture in the left neck followed by TDE.

This case involves chylothorax in a 58-year-old male due to disruption of the main TD during esophagectomy, resulting in disjointed leaks from 2 separate areas related to a single complex injury. Lymphangiography and embolization via both transcervical and transabdominal approaches were performed to stop the leak.

Anatomy of the lymphovenous valve of the thoracic duct in humans

The majority of lymph generated in the body is returned to the blood circulation via the lymphovenous junction (LVJ) of the thoracic duct (TD). A lymphovenous valve (LVV) is thought to guard this junction by regulating the flow of lymph to the veins and preventing blood from entering the lymphatic system. Despite these important functions, the morphology and mechanism of this valve remains unclear. The aim of this study was to investigate the anatomy of the LVV of the TD. To do this, the TD and the great veins of the left side of the neck were harvested from 16 human cadavers. The LVJs from 12 cadavers were successfully identified and examined macroscopically, microscopically, and using microcomputed tomography. In many specimens, the TD branched before entering the veins. Thus, from 12 cadavers, 21 LVJs were examined. Valves were present at 71% of LVJs (15/21) and were absent in the remainder. The LVV, when present, was typically a bicuspid semilunar valve, although the relative size and position of its cusps were variable. Microscopically, the valve cusps comprised luminal extensions of endothelium with a thin core of collagenous extracellular matrix. This study clearly demonstrated the morphology of the human LVV. This valve may prevent blood from entering the lymphatic system, but its variability and frequent absence calls into question its utility. Further structural and functional studies are required to better define the role of the LVV in health and disease.

A Canine Model for Lymphangiography and Thoracic Duct Access

OBJECTIVE

To evaluate the technical feasibility of intranodal lymphangiography and thoracic duct (TD) access in a canine model.

MATERIALS AND METHODS

Five male mongrel dogs were studied. The dog was placed in the supine position, and the most prominent lymph node in the groin was accessed using a 26-gauge spinal needle under ultrasonography (US) guidance. If the cisterna chyli (CC) was not opacified by bilateral lymphangiography, the medial iliac lymph nodes were directly punctured and Lipiodol was injected. After opacification, the CC was directly punctured with a 22-gauge needle. A 0.018-in microguidewire was advanced through the CC and TD. A 4-Fr introducer and dilator were then advanced over the wire. The microguidewire was changed to a 0.035-in guidewire, and this was advanced into the left subclavian vein through the terminal valve of the TD. Retrograde TD access was performed using a snare kit.

RESULTS

US-guided lymphangiography (including intranodal injection of Lipiodol [Guerbet]) was successful in all five dogs. However, in three of the five dogs (60%), the medial iliac lymph nodes were not fully opacified due to overt Lipiodol extravasation at the initial injection site. In these dogs, contralateral superficial inguinal intranodal injection was performed. However, two of these three dogs subsequently underwent direct medial iliac lymph node puncture under fluoroscopy guidance to deliver additional Lipiodol into the lymphatic system. Transabdominal CC puncture and cannulation with a 4-Fr introducer was successful in all five dogs. Transvenous retrograde catheterization of the TD (performed using a snare kit) was also successful in all five dogs.

CONCLUSION

A canine model may be appropriate for intranodal lymphangiography and TD access. Most lymphatic intervention techniques can be performed in a canine using the same instruments that are employed in a clinical setting.

A Rare Case of Chylothorax after Heart Transplantation

Chylothorax is an exceedingly rare but serious complication of orthotopic heart transplantation (OHT). Prompt diagnosis and appropriate management are essential for a good outcome. Management is similar to that of nontransplant patients, but special attention must be given to patients' nutritional and immunological status. Relevant literature on this topic is limited. We describe our experience in the management of chylothorax after OHT and provide a summary of reported cases of this complication after isolated heart and combined heart/lung transplant.

New insights into acute pancreatitis

The incidence of acute pancreatitis continues to increase worldwide, and it is one of the most common gastrointestinal causes for hospital admission in the USA. In the past decade, substantial advancements have been made in our understanding of the pathophysiological mechanisms of acute pancreatitis. Studies have elucidated mechanisms of calcium-mediated acinar cell injury and death and the importance of store-operated calcium entry channels and mitochondrial permeability transition pores. The cytoprotective role of the unfolded protein response and autophagy in preventing sustained endoplasmic reticulum stress, apoptosis and necrosis has also been characterized, as has the central role of unsaturated fatty acids in causing pancreatic organ failure. Characterization of these pathways has led to the identification of potential molecular targets for future therapeutic trials. At the patient level, two classification systems have been developed to classify the severity of acute pancreatitis into prognostically meaningful groups, and several landmark clinical trials have informed management strategies in areas of nutritional support and interventions for infected pancreatic necrosis that have resulted in important changes to acute pancreatitis management paradigms. In this Review, we provide a summary of recent advances in acute pancreatitis with a special emphasis on pathophysiological mechanisms and clinical management of the disorder.

Interventional Therapies for Thoracic Duct Injury and Intractable Chylothorax

Injury to the thoracic duct with resultant chylothorax can cause significant patient morbidity and mortality. Conservative treatment strategies often fail to address the problem. Open surgical and percutaneous approaches are often required to manage patients with refractory chylothorax. This review describes in detail the major role of minimally invasive interventional therapies for thoracic duct (TD) injury. The review emphasizes strategies for identifying the TD on preprocedural imaging and describes various techniques for percutaneous access to the TD. The advantages and disadvantages of several approaches for accessing the duct are discussed. The technique of duct embolization is highlighted. The role of the minimally invasive percutaneous approach over open surgical approaches is discussed with a review of clinical outcomes, as reported in the literature. This review will also briefly discuss the surgical approach to TD ligation.

Lymphangiography and Post-lymphangiographic Multidetector CT for Preclinical Lymphatic Interventions in a Rabbit Model

PURPOSE

To describe the feasibility of lymphangiography and the visibility of the lymphatic system using post-lymphangiographic multidetector CT (MDCT) for preclinical lymphatic interventions in a rabbit model.

MATERIALS AND METHODS

Lymphangiography via the popliteal lymph node or vessel after surgical exposure was performed, using six healthy female Japanese White rabbits. Lipiodol was manually injected for lymphangiography. Post-lymphangiographic MDCT examinations were performed in all rabbits. The dataset images were subjected to image processing analysis utilizing the three-dimensional maximum intensity projection technique. Three reviewers evaluated the degree of depiction of the lymphatic system using a four-point visual score (1, poor; 2, fair; 3, good; 4, excellent). The distance between the body surface and cisterna chyli was measured on post-lymphangiographic MDCT axial image.

RESULTS

Lymphangiography was successfully performed in all rabbits. The popliteal lymph node was detectable in 90%. The visualization of lymphatic system via the popliteal node was achieved in 89%. Mean visual scores of > 3.0 were realized by the right femoral lymphatic vessel, left femoral lymphatic vessel, left iliac lymphatic vessel, left lumbar lymphatic trunks and cisterna chyli, whereas mean visual scores of < 3.0 were yielded by the right iliac lymphatic vessel, right lumbar lymphatic trunks and thoracic duct. The distance between the body surface and cisterna chyli on post-lymphangiographic MDCT axial images was 4.33 ± 0.14 cm.

CONCLUSION

Lymphangiography is feasible, and the visibility of the lymphatic system on post-lymphangiographic MDCT in a rabbit model provides enough information for interventional radiologists to perform preclinical lymphatic interventions.

Chylothorax secondary to venous outflow obstruction treated with transcervical retrograde thoracic duct cannulation with embolization and venous reconstruction

A chylothorax may be due to either direct trauma or occlusion of the thoracic duct. Treatments include antegrade or retrograde glue and coil embolization as well as thoracic duct stent graft placement. This report describes a patient with chylothorax secondary to venous outflow occlusion. Left upper extremity venography demonstrated multifocal left brachiocephalic and axillary vein occlusions with retrograde filling of an engorged and disrupted thoracic duct. Retrograde thoracic duct lymphangiography with embolization and left upper extremity venous reconstruction were performed with complete resolution of chylothorax.

Thoracic Duct Embolization: Analysis of Practice Patterns

BACKGROUND

Thoracic duct embolization (TDE) has become the standard treatment for atraumatic and traumatic chylothoraces. Numerous approaches to embolization including intranodal lymphangiography, transabdominal, and retrograde catheterization of the thoracic duct have become the preferred methods for the treatment of chyle leaks. The purpose of this study was to determine training, treatment techniques, outcomes, and practice patterns of practitioners performing TDE.

METHODS

From September to October of 2017, a 34-question survey focusing on training, treatment techniques, outcomes, and practice patterns of TDE was distributed through the Open Forum of the Society of Interventional Radiology Connect website. Fifty-four practitioners completed the entire survey. Percentages were calculated for answers to the questions. Chi-squared analysis was performed, comparing data from academic center respondents, private practice settings, and hybrid practice settings. P values < 0.5 were considered statistically significant.

RESULTS

All responses were from interventional radiologists. Forty-seven practitioners (87.0%) performed TDE in the United States, and 1 performed (1.9%) abroad; 6 practitioners (11.1%) did not perform TDE. Of all, 88.9% (n = 48) performed TDE in academic (n = 24; 50%), private (n = 17; 35.4%), or hybrid (n = 6; 12.5%) practice settings. For diagnostic lymphangiography, 100% (n = 48) performed intranodal pelvic lymphangiography. A 25-gauge needle was used by 77.1% (n = 37) to access pelvic lymph nodes, and most (83.3%; n = 40) reported using manual hand injection to administer ethiodized oil. Nine of 24 (37.5%) respondents in academic practice and 15 of 23 (65.2%) in private practice were successful in cannulating the thoracic duct >80% of the time. Most referrals were from thoracic surgery (n = 47; 97.9%).

CONCLUSIONS

TDE is performed by practitioners in both academic and private practice settings. Treatment techniques were similar for a majority of operators. Technical success rates were higher in private practice. Most referrals were from thoracic surgery.

Endolymphatic Thoracic Duct Stent-Graft Reconstruction for Chylothorax: Approach, Technical Success, Safety, and Short-term Outcomes

BACKGROUND

To report approach, technical success, safety, and short-term outcomes of thoracic duct stent-graft reconstruction for the treatment of chylothorax.

METHODS

Two patients, 1 (50%) male and 1 (50%) female, with mean age of 38 years (range: 16-59 years) underwent endolymphatic thoracic duct stent-graft reconstruction between September 2016 and July 2017. Patients had radiographic left-sided chylothoraces (n = 2) from idiopathic causes (n = 1) and heart transplantation (n = 1). In both (100%) patients, antegrade lymphatic access was used to opacify the thoracic duct after which retrograde access was used for thoracic duct stent-graft placement. Pelvic lymphangiography technical success, antegrade cisterna chyli cannulation technical success, thoracic duct opacification technical success, retrograde thoracic duct access technical success, thoracic duct stent-graft reconstruction technical success, ethiodized oil volume, contrast volume, estimated blood loss, procedure time, fluoroscopy time, radiation dose, clinical success, complications, deaths, and follow-up were recorded.

RESULTS

Pelvic lymphangiography, antegrade cisterna chyli cannulation, thoracic duct opacification, retrograde thoracic duct access, and thoracic duct stent-graft reconstruction were technically successful in both (100%) patients. Mean ethiodized oil volume was 8 mL (range: 5-10 mL). Mean contrast volume was 13 mL (range: 5-20 mL). Mean estimated blood loss was 13 mL (range: 10-15 mL). Mean fluoroscopy time was 50.4 min (range: 31.2-69.7 min). Mean dose area product and reference air kerma were 954.4 μGmy² (range: 701-1,208 μGmy²) and 83.5 mGy (range: 59-108 mGy), respectively. Chylothorax resolved in both (100%) patients. There were no minor or major complications directly related to the procedure.

CONCLUSIONS

Thoracic duct stent-graft reconstruction may be a technically successful and safe alternative to thoracic duct embolization, disruption, and surgical ligation for the treatment of chylothorax. Additional studies are warranted.

Recurrent chylothorax: a clinical mystery

Chylothorax is an unusual cause of pleural effusion, typically caused by trauma or malignancy. Waldenstrom's macroglobulinaemia (WM) is a clinicopathological entity demonstrating lymphoplasmacytic lymphoma in the bone marrow with an IgM monoclonal gammopathy in the blood. Recurrent chylous effusions are often resistant to conservative treatment and may require surgical intervention. We present a unique case of a 50-year-old woman with recurrent chylothorax secondary to WM that completely resolved with ibrutinib therapy. To our knowledge, this is the eighth such case reported in literature and the first case of successful resolution of chylothorax with monoclonal antibody therapy.