Lymphatic Intervention, the Frontline of Modern Lymphatic Medicine: Part II. Classification and Treatment of the Lymphatic Disorders

MR Lymphangiography: Congenital Lymphatic Flow Disorders

ABSTRACT

Congenital lymphatic flow disorders collectively refer to a heterogeneous group of diseases that manifest as chylothorax, chylous ascites, intestinal lymphangiectasia, protein-losing enteropathy, and peripheral extremity or genital lymphedema, all in the absence of identifiable injury to the lymphatic system. We have only recently begun to understand congenital lymphatic flow disorders through the ability to image lymph flow dynamically. Intranodal dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) is a crucial technique for imaging lymphatic flow in pediatric patients with congenital lymphatic flow disorders. However, as lymphatic imaging is still a nascent discipline with many uncertainties regarding optimal imaging and treatment, effective patient management requires a comprehensive understanding of imaging techniques, disease pathophysiology, and multidisciplinary treatment approaches. Above all, a fundamental understanding of the physiological lymphatic flow of the central conducting lymphatics is essential for the correct interpretation of DCMRL images. This knowledge helps to avoid unnecessary examinations, erroneous diagnoses, and potentially harmful treatment approaches. This review provides an overview of the methods, advantages, and precautions for interpreting the DCMRL examination, a state-of-the-art lymphatic system imaging technique, and shares various case studies.

Appropriate Use Criteria Committees: The professional society role in the development and implementation of Appropriate Use Criteria

Vascular surgeons have the ability to manage and intervene on numerous vascular diseases of both the arterial and venous systems. With the growing number of interventions available as endovascular technology evolves, it is important to determine when a procedure is safely indicated for a vascular surgery patient. Appropriate Use Criteria (AUC) offer synthesized clinical information and practice standards that can aid clinicians in making these management decisions. Professional societies, such as the Society for Vascular Surgery, bring experts in the field together to collaborate and create AUC for various vascular diseases and interventions. It is essential to publish these criteria in peer-reviewed journals, as well as make them available on public websites so the information is available to vascular surgeons and interventionalists from other specialties who also treat patients with vascular disease. Cardiology, interventional radiology, and interventional nephrology are some other specialties that perform procedures for vascular disease, and vascular interventions by nonsurgeon specialists continue to increase. The Society for Vascular Surgery has published AUC on intermittent claudication, carotid disease, and abdominal aneurysm management. These are intended to guide practice, but also have highlighted areas for improvement that would allow for more universal implementation of AUC in vascular patient care across medical specialties. Increased intersocietal participation and perhaps inclusion of government and other payer participation will allow professional society-sponsored AUC to evolve, resulting in coordinated, appropriate care for vascular surgery patients.

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.

Thoracic Duct Embolization for Treatment of Chyle Leakage After Thyroidectomy and Neck Dissection

OBJECTIVE

This study aimed to evaluate the safety and efficacy of intranodal lymphangiography and thoracic duct embolization (TDE) for chyle leakage (CL) after thyroid surgery.

MATERIALS AND METHODS

Fourteen patients who underwent intranodal lymphangiography and TDE for CL after thyroid surgery were included in this retrospective study. Among the 14 patients, 13 underwent bilateral total thyroidectomy with neck dissection (central compartment neck dissection [CCND], n = 13; left modified radical neck dissection (MRND), n = 11; bilateral MRND, n = 2), and one patient underwent left hemithyroidectomy with CCND. Ten patients (76.9%) had high-output CL (> 500 mL/d). Before the procedure, surgical intervention was attempted in three patients (thoracic duct ligation, n = 1; lymphatic leakage site ligation, n = 2). Lymphangiographic findings, technical and clinical successes, and complications were analyzed. Technical success was defined as the successful embolization of the thoracic duct after access to the lymphatic duct via the transabdominal route. Clinical success was defined as the resolution of CL or surgical drain removal.

RESULTS

On lymphangiography, ethiodized oil leakage near the surgical bed was identified in 12 of 14 patients (85.7%). The technical success rate of TDE was 78.6% (11/14). Transabdominal antegrade access was not feasible due to the inability to visualize the identifiable cisterna chyli or a prominent lumbar lymphatic duct. Among patients who underwent a technically successful TDE, the clinical success rate was 90.1% (10/11). The median time from the procedure to drain removal was 3 days (with a range of 1-13 days) for the 13 patients who underwent surgical drainage. No CL recurrence was observed during the follow-up period (ranging from 2-44 months; median, 8 months). There were no complications, except for one case of chylothorax that developed after TDE.

CONCLUSION

TDE appears to be a safe and effective minimally invasive treatment option for CL after thyroid surgery, with acceptable technical and clinical success rates.

Lymphatic Leakage in Pediatric Heart Transplantation: Early Recognition and Timely Management with Interventional Radiologic and Endoscopic Therapy

Protein-losing enteropathy (PLE) is a severe complication of the Fontan procedure that leads to systemic complications owing to enteric protein loss. Hepatoduodenal lymphatic leakage resulting from increased lymphatic pressure is one such complication. We present the case of a pediatric heart transplant patient who experienced refractory PLE symptoms requiring serial albumin infusions and exhibited lymphatic leakage into the duodenum. Using diagnostic lymphangiography and endoscopy, we identified the affected area and treated it successfully with endoscopic sclerotherapy using ethanolamine injection. This treatment allowed for the cessation of lymphatic fluid and may serve as a potential intervention for PLE-associated hepatoduodenal lymphatic leakage. The present case highlights the importance of early recognition and timely intervention with radiology and endoscopic therapy to manage PLE and its associated complications.