Neonatal lymphatic flow disorders: impact of lymphatic imaging and interventions on outcomes

Ultrasound-guided needle positioning confirmation with injection of saline solution for nodal dynamic contrast-enhanced MR-lymphangiography in pediatric patients

PURPOSE

To assess the success rate of confirmation of ultrasound-guided intranodal needle positioning by saline injection for dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) in pediatric patients.

MATERIAL AND METHODS

Data from children undergoing nodal DCMRL after ultrasound-guided needle positioning into inguinal lymph nodes and validation of the needle position by injection of plain saline solution between 05/2020 and 12/2022 were reviewed. On injection of saline solution, adequate needle position was confirmed by lymph node distension without leakage. Detection rates and lymph node diameters were recorded. Technical success of needle placement was defined as enhancement of ipsilateral iliac draining lymph vessels on DCMRL, while clinical success was based on enhancement of central lymphatics and/or lymphatic pathologies being observed.

RESULTS

One hundred sixteen DCMRL were performed in 90 children (58 male, mean age 6.1 years, range 3 weeks-18 years). In 232/232 groins lymph nodes were identified on ultrasound with a mean diameter of 2.5 mm (smallest diameter 1 mm in n = 24 patients). Due to skin inflammation, no puncture was performed in 2/232 groins. Saline injection showed lymph node distension in 230/230 punctured nodes. On MR contrast injection enhancement of draining lymph vessels was seen in 228/230 nodes. In 1/230 nodes, in-bore needle retraction led to lymphatic enhancement, so a total of 229/230 needle placements were technically successful. One of the 230 DCMRLs was successful with only a unilateral contrast application. Overall, 116/116 DCMRLs were clinically successful.

CONCLUSION

Confirmation of ultrasound-guided needle positioning for nodal DCMRL using saline injection is a reliable technique with a very high success rate in pediatric patients with small lymph nodes.

KEY POINTS

Question Evaluation of ultrasound-guided injection needle positioning for dynamic contrast-enhanced MR-lymphangiography in children requires validation. Findings Confirmation of needle positioning by ultrasound-guided saline injection is a reliable technique with a very high success rate for MR-lymphangiography in pediatric patients. Clinical relevance Intranodal needle position for dynamic contrast-enhanced lymphangiography can be confirmed with a very high success rate using saline injection alone in a pediatric cohort.

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.

Neonatal perspective on central lymphatic disorders

Lymphatic disorders presenting in the first year of life are difficult to identify and manage given the broad range of underlying etiologies. Neonatal lymphatic disease arising from congenital or acquired conditions results in the abnormal accumulation of lymph fluid in the pleura (chylothorax), peritoneum (chylous ascites) and skin (edema/anasarca). There is also increasing recognition of lymphatic losses through the intestine resulting in protein-losing enteropathy (PLE). While the incidence of lymphatic disorders in neonates is unclear, advances in genetic testing and lymphatic imaging are improving our understanding of the underlying pathophysiology. Despite these advancements, medical management of neonatal lymphatic disorders remains challenging and variable among clinicians.

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.

Surgical management of thoracic duct anomalies

The development of new imaging techniques for the study of the central lymphatic system allows us to understand the anatomy and pathophysiology of all the disorders of the thoracic duct. With the help of catheters placed percutaneously in the thoracic duct, we can do now complex operations on the thoracic duct to restore its functionality. Advance imaging, expert percutaneous skills, and expert microsurgical skills are critical to the success of these interventions.

Surgical Management of Central Lymphatic Conduction Disorders: A Review

AIM

Recent advances in lymphatic imaging allow understanding the pathophysiology of lymphatic central conduction disorders with great accuracy. This new imaging data is leading to a wide range of novel surgical interventions. We present here the state-of-the-art imaging technology and current spectrum of surgical procedures available for patients with these conditions.

METHOD

Descriptive report of the newest lymphatic imaging technology and surgical procedures and retrospective review of outcome data.

RESULTS

There are currently two high-resolution imaging modalities for the central lymphatic system: multi-access dynamic contrast-enhanced MR lymphangiogram (DCMRL) and central lymphangiography (CL). DCMRL is done by accessing percutaneously inguinal and mesenteric lymph nodes and periportal lymphatics vessels. DCMRL provides accurate anatomical and dynamic data on the progression, or lack thereof, of the lymphatic fluid throughout the central lymphatic system. CL is done by placing a catheter percutaneously in the thoracic duct (TD). Pleural effusions are managed by pleurectomy and intraoperative lymphatic glue embolization guided by CL. Anomalies of the TD are managed by TD-to-vein anastomosis and/or ligation of aberrant TD branches. Chylous ascites and organ-specific chylous leaks are managed by intraoperative glue embolization, surgical lymphocutaneous fistulas, and ligation of aberrant peripheral lymphatic channels, among several other procedures.

CONCLUSION

The surgical management of lymphatic conduction disorders is a new growing field within pediatric general surgery. Pediatric surgeons should be familiar with the newest imaging modalities of the lymphatic system and with the surgical options available for patients with these complex surgical conditions to provide prompt treatment or referral.

LEVEL OF EVIDENCE

V.

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.

Management of Congenital and Postoperative Chylothorax: Use of Thoracoscopic Lymphatic Leak Ligations with Intraoperative ICG Lymphangiography

BACKGROUND

Congenital chylothorax (CCT) and postoperative chylothorax (POCT) are rare and difficult to treat. We report our treatment strategy and outcomes for chylothorax, including thoracoscopic surgery with indocyanine-green (ICG) near-infrared fluorescence lymphangiography.

METHODS

A retrospective review of patients with CCT and POCT from 2014 to 2021 was performed. After definitive diagnosis, conservative treatments with octreotide, followed by intravenous steroids as needed, were performed. Patients who were refractory to conservative treatment were transferred to surgical treatment, consisting of thoracoscopic lymphatic leak ligations using ICG intraoperative lymphangiography. The effectiveness of conservative and surgical treatment was then examined.

RESULTS

We included 19 cases of CCT and 31 cases of POCT. The 31 POCT patients included 23 of 84 postoperative patients with congenital diaphragmatic hernia (CDH), 7 of 54 postoperative patients with esophageal atresia (EA), and 1 of 3 postoperative patients with lymphatic malformation. The efficacy of conservative treatment was 12/19 for CCT, 22/23 for CDH, and 4/7 for EA. Surgical intervention was performed in 10 patients, and the rate of resolution of chylothorax within 3 weeks after surgery was 90%.

CONCLUSION

Thoracoscopic lymphatic leak ligations with intraoperative ICG lymphangiography are feasible and useful in patients with chylothorax refractory to conservative treatment.

LEVEL OF EVIDENCE

Level IV.

Surgical creation of lymphocutaneous fistulas for the management of infants with central lymphatic obstruction

PURPOSE

Central lymphatic obstructions are associated with anasarca and high mortality. We hypothesized that opening dilated cutaneous lymphatic channels by creating a lymphocutaneous fistula (LCF) would decompress the lymphatic circulation and improve anasarca.

METHODS

We reviewed all patients that had at least one LCF created between 9/2019 and 12/2022. LCF efficacy was determined by changes in weight, urine/diuresis, ventilation, and clinical status.

RESULTS

We created eleven LCFs in four infants. LCFs initially drained 108 cc/kg/d (IQR68-265 cc/kg/d). Weights significantly decreased after LCF creation (6.9 [IQR6.1-8.1] kg vs. 6.1 [IQR 4.9-7.6] kg, P = 0.042). Ventilatory support decreased significantly in all patients after at least one LCF was created, and 3/4 patients (75%) had significantly lower peak inspiratory pressures (28 [IQR 25-31] cmH2O vs. 22 [IQR 22-24] cmH2O, P = 0.005; 36 [IQR36-38] cmH2O vs. 33 [IQR 33-35] cmH2O, P = 0.002; 36 [IQR 34-47] cmH2O vs. 28 [28-31] cmH2O, P = 0.002). LCFs remained patent for 29d (IQR 16-49d). LCFs contracted over time, and 6/11 (54.5%) were eventually revised. There were no complications. Two patients died from overwhelming disease, one died from unrelated causes, and one remains alive 29 months after their initial LCF.

CONCLUSION

LCFs provide safe and effective temporary lymphatic decompression in patients with central lymphatic obstruction. While LCFs are not a cure, they can serve as a bridge to more definitive therapies or spontaneous lymphatic remodeling.

LEVEL OF EVIDENCE

IV.

Understanding the next circulation: lymphatics and what the future holds

PURPOSE OF REVIEW

The lymphatic system was previously considered the forgotten circulation because of an absence of adequate options for imaging and intervention. However, recent advances over the last decade have improved management strategies for patients with lymphatic disease, including chylothorax, plastic bronchitis, ascites, and protein-losing enteropathy.

RECENT FINDINGS

New imaging modalities have enabled detailed visualization of lymphatic vessels to allow for a better understanding of the cause of lymphatic dysfunction in a variety of patient subsets. This sparked the development of multiple transcatheter and surgery-based techniques tailored to each patient based on imaging findings. In addition, the new field of precision lymphology has added medical management options for patients with genetic syndromes, who have global lymphatic dysfunction and typically do not respond as well to the more standard lymphatic interventions.

SUMMARY

Recent developments in lymphatic imaging have given insight into disease processes and changed the way patients are managed. Medical management has been enhanced and new procedures have given patients more options, leading to better long-term results.

Intranodal cone-beam computed tomographic lymphangiography with water-soluble iodinated contrast agent for evaluating chylothorax in infants - preliminary experience at a single institution

This brief report demonstrates the diagnostic utility of cone-beam CT lymphangiography (CBCTL) with intranodal injection of water-soluble iodinated contrast agent for assessing lymphatic disorders in two infants who were contraindicated for MRI and oil-based contrast agent. Both infants had dextro-transposition of the great arteries (d-TGA) and presented with high-output chylothoraces that were recalcitrant to conservative medical therapy. Both infants were diagnosed with central lymphatic flow disorder based on the CBCTL findings.

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.

How we approach pediatric congenital chylous effusions and ascites

Congenital lymphatic leak may develop in patients with maldeveloped lymphatics and result in life-threatening fluid and electrolyte imbalance, protein deficiency, and immunodeficiency. Rapid diagnosis and therapy are necessary to prevent these complications; however, the field lacks clinical trials to support standardized diagnostic treatment guidelines. We present our current multidisciplinary approach to the diagnosis and management of congenital lymphatic leak including chylous pleural effusions and ascites. Depending on the rate of lymphatic leak, therapy can range from observation with nutritional modifications to surgical and interventional procedures aimed to reduce lymphatic drainage. Modalities to image central and peripheral lymphatics have advanced considerably. Genetic variants and subsequent targets that drive lymphatic maldevelopment have expanded the repertoire of possible pharmacotherapeutic options.

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.

Novel use of a Synovis™ coupler device for a surgical lymphovenous anastomosis for the treatment of refractory chylothorax in a patient with central lymphatic flow disorder

Refractory post-operative chylothorax in congenital heart disease is difficult to treat. We present a case of intractable neonatal chylothorax after cardiac surgery due to central lymphatic flow disorder that was treated by creating a lymphovenous anastomosis of the thoracic duct to the left external jugular vein for definitive treatment.

Dynamic contrast-enhanced magnetic resonance lymphangiography

Lymphatic flow disorders include a broad spectrum of abnormalities that can originate in the lymphatic or the venous system. The development of these disorders is multifactorial and is most commonly associated with congenital heart diseases and palliative surgeries that these patients undergo. Central lymphatic disorders might be secondary to traumatic leaks, lymphatic overproduction, conduction abnormalities or lymphedema, and they can progress to perfusion anomalies. Several imaging modalities have been used to visualize the lymphatic system. However, the imaging of central lymphatic flow has always been challenging. Dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) allows for visualization of central lymphatic flow disorders and has been recently applied for the assessment of plastic bronchitis, protein-losing enteropathy, chylothorax and chylopericardium, among other lymphatic disorders. The hepatic and mesenteric accesses are innovative and promising techniques for better identification and understanding of these abnormalities. The main objectives of this review are to discuss the physiology and anatomy of the lymphatic system and review the current uses of DCMRL in the diagnosis and management of lymphatic flow disorders.

Chylothorax: A Stepwise Approach to Diagnosis and Treatment

Chylothorax, a lymphatic flow disorder characterized by an abnormal circulation of lymph fluid into the pleural cavity, is the most common cause of pleural effusions during the neonatal period. This condition affects 1/15,000 neonates every year. Affected neonates often manifest with respiratory distress, electrolyte imbalances, sepsis, and even immunodeficiencies. Mortality risk is highest among neonates undergoing cardiac surgery as well as those with associated hydrops fetalis. Conservative treatment options include bowel rest with administration of parenteral nutrition, followed with medium-chain triglyceride enteral feedings, and octreotide therapy. Severe or persistent cases require surgical intervention. This can involve a unilateral or bilateral pleurectomy and thoracic duct ligation, with or without pleurodesis. Early identification and successful treatment of this condition is contingent upon awareness of the most current evidence and a timely cross-disciplinary approach to care.