The lymphatic system plays an important role in immune regulation, transport of metabolites, and fluid balance. The key circulatory role of the lymphatic system is to transport fluid from tissue back ...into the venous system via lymphovenous connections. Despite the centuries-old recognition of this key role, there has been poor understanding of lymphatic flow pathophysiology because of a lack of a simple reliable noninvasive clinical lymphatic imaging method. This lack of clinical imaging has limited the treatment options for patients with lymphatic flow disorders. Recent development of noncontrast magnetic resonance (MR) lymphangiogram and dynamic contrast MR lymphangiography make it possible to visualize central lymphatic anatomy and flow dynamics with high spatial and temporal resolution. Dynamic contrast MR lymphangiography has provided insight into understanding the pathophysiology of several pulmonary lymphatic flow disorders and provides guidance for interventional procedures. Another important development has been intranodal lymphangiogram, which has now replaced pedal lymphangiogram as the main lymphatic interventional modality, and which provides quick and reliable access to the central lymphatic ducts for interventional procedures. These new techniques have led to a resurgence in interest in the lymphatic system and the development of new treatments for patients with lymphatic flow disorders.
Abstract Background Post-operative chylothorax in patients with congenital heart disease is a challenging problem with substantial morbidity and mortality. Currently, the etiology of chylothorax is ...poorly understood and treatment options are limited. Objectives This study aimed to report lymphatic imaging findings, determine the mechanism of chylothorax after cardiac surgery, and analyze the outcomes of lymphatic embolization. Methods We conducted a retrospective review of 25 patients with congenital heart disease and post-operative chylothorax who presented for lymphatic imaging and intervention between July 2012 and August 2016. Results Based on dynamic contrast-enhanced magnetic resonance lymphangiography and intranodal lymphangiography, we identified 3 distinct etiologies of chylothorax: 2 patients (8%) with traumatic leak from a thoracic duct (TD) branch, 14 patients (56%) with pulmonary lymphatic perfusion syndrome (PLPS), and 9 patients (36%) with central lymphatic flow disorder (CLFD), the latter defined as abnormal central lymphatic flow, effusions in more than 1 compartment, and dermal backflow. Patients with traumatic leak and PLPS were combined into 1 group of 16 patients without CLFD, of whom 14 (88%) had an intact TD. Sixteen patients underwent lymphatic intervention, including complete TD embolization. All 16 patients had resolution of chylothorax, with a median of 7.5 days from intervention to chest tube removal and 15 days from intervention to discharge. The 9 patients with CLFD were considered a separate group, of whom 3 (33%) had an intact TD. Seven patients underwent lymphatic intervention but none survived. Conclusions Most patients in this study had nontraumatic chylothorax and dynamic contrast-enhanced magnetic resonance lymphangiography was essential to determine etiology. Lymphatic embolization was successful in patients with traumatic leak and PLPS and, thus, should be considered first-line treatment. Interventions in patients with CLFD were not successful to resolve chylothorax and alternate approaches need to be developed.
To demonstrate the feasibility of dynamic four-dimensional ( 4D four-dimensional ) intranodal contrast material-enhanced magnetic resonance (MR) lymphangiography with inguinal lymph node injection of ...gadopentetate dimeglumine.
All procedures were performed in accordance with the guidelines on the use of animals in research and were approved by the animal care and use committee. Five swine underwent nonenhanced MR lymphangiography with a heavily T2-weighted MR sequence, bilateral inguinal lymph node injection of 2 mL of undiluted gadopentetate at a rate of 1 mL/min, and 60 minutes of MR imaging with T1-weighted high-spatial- and high-temporal-resolution MR angiography. Images were reviewed by a radiologist with expertise in lymphatic imaging and a pediatric cardiac MR imaging specialist for visualization of the thoracic duct ( TD thoracic duct ). Categorical variables were compared by using the exact conditional McNemar test. A difference with a P value less than .05 was considered significant.
The TD thoracic duct was visualized in three of the five animals (60%) on T2-weighted images. In contrast, the TD thoracic duct was visualized in all five of the animals (100%) after contrast agent injection (P = .25). The median time for flow of the contrast agent through the lymphatic system to the TD thoracic duct outlet was 244 seconds (range, 201-387 seconds). Enhancement was seen in the TD thoracic duct up to 1 hour after injection. All animals survived without any complications.
Dynamic 4D four-dimensional contrast-enhanced MR lymphangiography with intranodal injection of gadopentetate dimeglumine is feasible, produces good images of the central lymphatic system, and demonstrates the time course of flow of contrast agent up the central lymphatic ducts. On the basis of the results of this initial animal experiment, it appears that dynamic 4D four-dimensional contrast-enhanced MR lymphangiography is potentially feasible and safe with commercially available contrast agents.
Abstract Background Protein-losing enteropathy (PLE), characterized by loss of proteins in the intestine, is a devastating complication in patients with congenital heart disease. The cause of PLE is ...unknown, but lymphatic involvement has been suspected. Objectives The authors evaluated the use of lymphangiographic imaging and liver lymphatic embolization as a treatment for PLE. Methods This was a single-center, retrospective review of imaging and interventions used in 8 consecutive patients with liver lymphatic embolization and congenital heart disease with elevated central venous pressure complicated by PLE. Results Liver lymphangiography was performed in 8 patients (5 males, 3 females; median age, 21 years), 7 of whom demonstrated leakage of liver lymph into the duodenum through abnormal hepatoduodenal lymphatic communications. This was confirmed by duodenoscopy with simultaneous injection of isosulfan blue dye into the liver lymphatics in 6 of 7 patients. Liver lymphatic embolization with ethiodized oil in 2 patients resulted in a temporary increase in albumin blood level and symptom improvement in 1 patient, but was complicated by duodenal bleeding in both patients. Of the remaining 6 patients, liver lymphatic embolization with n-butyl cyanoacrylate glue resulted in sustained improvement of the serum albumin level and symptoms in 3 patients, temporary improvement in 2 patients, and no change in 1 patient with median follow-up of 135 days (range, 84 to 1,005 days). Conclusions The authors demonstrated liver lymph leakage as a cause of PLE in patients with congenital heart disease and elevated central venous pressure. Lymphatic embolization led to improved albumin levels and relief of symptoms. Further experience with the technique is needed to determine long-term outcome of this procedure.
Plastic bronchitis is a rare and often fatal complication of single-ventricle surgical palliation after total cavopulmonary connection. Although lymphatic abnormalities have been postulated to play a ...role in the disease process, the etiology and pathophysiology of this complication remain incompletely understood. Here we report on the etiology of plastic bronchitis in a child with total cavopulmonary connection as demonstrated by magnetic resonance (MR) lymphangiography. We also report on a new treatment of this disease. The patient underwent noncontrast T2-weighted MR lymphatic mapping and dynamic contrast MR lymphangiography with bi-inguinal intranodal contrast injection to determine the anatomy and flow pattern of lymph in his central lymphatic system. The MRI scan demonstrated the presence of a dilated right-sided peribronchial lymphatic network supplied by retrograde lymphatic flow through a large collateral lymphatic vessel originating from the thoracic duct. After careful analysis of the MRI scans we performed selective lymphatic embolization of the pathologic lymphatic network and supplying vessel. This provided resolution of plastic bronchitis for this patient. Five months after the procedure, the patient remains asymptomatic off respiratory medications.
Plastic bronchitis is a condition characterized by expectoration of branching bronchial casts. Although the mechanism of cast formation in adults with plastic bronchitis remains poorly understood, ...abnormal pulmonary lymphatic flow resulting in molding of congealing lymphatic fluids in the airway has been documented as a cause of the disease in children with congenital heart disease.
To use advanced lymphatic imaging techniques, including dynamic contrast-enhanced magnetic resonance (MR) lymphangiography (DCMRL) and intranodal lymphangiography, to investigate the mechanism of cast formation in adult patients with plastic bronchitis, and to evaluate the therapeutic outcome of percutaneous lymphatic embolization for these patients.
Seven adults (male/female = 3/4, mean age = 50 yr) who presented with expectoration of branching bronchial casts were evaluated. Lymphatic imaging included heavy T2-weighted MR imaging and DCMRL. All patients underwent bilateral intranodal lymphangiography and thoracic duct cannulation. In cases where abnormal pulmonary lymphatic flow was demonstrated, embolization of pulmonary lymphatics was performed.
DCMRL demonstrated the presence of abnormal pulmonary lymphatic flow in six of seven patients, which was confirmed by intranodal lymphangiography and thoracic duct injection to represent lymphatic reflux or communication with of abnormal lymphatic channels with airways. After lymphatic embolization using a combination of endovascular glue and coils, five patients reported immediate and complete resolution of the symptoms and one patient reported partial, but significant, improvement. Transient abdominal discomfort postprocedure was treated with analgesics and resolved before discharge in all subjects. The mean length of follow up was 11 months (range, 4.3-16 mo).
We demonstrated abnormal pulmonary lymphatic flow on DCMRL and intranodal lymphangiogram in six of seven adult patients referred with expectoration of branching casts. Based on these data, we postulate that many cases of idiopathic plastic bronchitis in adults have a lymphatic basis, and propose that the diagnosis be renamed "lymphatic plastic bronchitis" in those subjects to distinguish the disorder from the other forms. Percutaneous transabdominal catheterization and embolization of the pulmonary lymphatics is a safe and effective treatment for the acute manifestation of this disorder, but additional studies are needed to determine the long-term safety and durability of this approach.
Background Congestive heart failure is a leading cause of morbidity and mortality worldwide. One of the signs of congestive heart failure is fluid overload including pulmonary edema, peripheral ...edema, and ascites. The cause of fluid overload remains incompletely understood, and management of these patients continues to be a challenge. The role of lymphatic circulation abnormalities in the cause and pathophysiology of fluid overload also remains unclear. Here we report on a study in a large animal model of right heart failure caused by severe tricuspid regurgitation comparing cardiovascular and lymphatic findings in a group of animals that did not develop ascites with a group of animals that developed ascites. Methods and Results Thirteen Yorkshire pigs were included in this study divided into 2 groups. Group 1 included 6 animals that did not develop ascites, and Group 2 included 7 animals that had developed ascites. The groups were compared on hemodynamic parameters as well as comparison of the animal's lymphatic anatomy and function. There was no difference between the groups in degree of tricuspid regurgitation and central venous pressure, with inferior vena cava pressure measuring 11.6±1.6 versus 13.2±3.7 (
=0.534) and superior vena cava pressure measuring 12.0±2.3 versus 13.7±3.2 (
=0.366). There was also no difference between the groups in all measured hemodynamic parameters, including right ventricular pressure, pulmonary artery pressure, and left ventricular function. The weighted liver size in the ascites group was significantly larger than in the nonascites group (30.3±12.4 versus 63.3±14.0 mL/kg, respectively;
=0.001). The 2 groups also differed in the number of animals with regurgitant thoracic duct flow (Group 1: 1/6,17% versus Group 2: 6/7, 86%;
=0.029) and the minimal thoracic duct diameter (Group 1: 2.3±0.3 versus Group 2: 4.2±2.2;
=0.035). Conclusions In animals with right heart failure caused by severe tricuspid regurgitation, fluid overload did not correlate with hemodynamic parameters but rather with changes in the lymphatic system, including regurgitant lymphatic flow, minimal thoracic duct diameter, and liver size. This study is consistent with lymphatic dysfunction and not cardiovascular function playing a significant role in the cause of fluid overload. Further studies are needed to confirm these findings.
Objectives
To report on our initial experience with intramesenteric (IM) dynamic contrast magnetic resonance lymphangiography (DCMRL) for evaluation of the lymphatics in patients with concern for ...mesenteric lymphatic flow disorders and to compare IM-DCMRL with intrahepatic (IH) and intranodal (IN) DCMRL.
Methods
This is a retrospective review of imaging findings in 15 consecutive patients who presented with protein losing enteropathy (PLE) and/or ascites undergoing IM-DCMRL, IH-DCMRL, and IN-DCMRL. The IM-DCMRL technique involves the injection of a gadolinium contrast agent into the mesenteric lymphatic ducts or lymph nodes followed by imaging of the abdomen and chest with dynamic time-resolved MR lymphangiography.
Results
IM-DCMRL was successfully performed in 14/15 (93%) of the patients. When comparing IN-DCMRL with IM-DCMRL, there was a significant difference in the visualization of dermal backflow (
p
= 0.014), duodenal perfusion (
p
= 0.003), duodenal leak (
p
= 0.014), and peritoneal leak (
p
= 0.003). IM-DCMRL demonstrated peritoneal leak in 7 patients in contrast to IH-DCMRL which demonstrated leak in 4 patients and IN-DCMRL which did not demonstrate any peritoneal leaks. Duodenal leaks were seen by IH-DCMRL in 9 patients versus 5 with IM-DCMRL and none with IN-DCMRL. In one patient with congenital PLE, the three modalities showed different disconnected flow patterns with duodenal leak only seen by IM-DCMRL. There were no short-term complications from the procedures.
Conclusions
IM-DCMRL is a feasible imaging technique for evaluation of the mesenteric lymphatics. In certain mesenteric lymphatic flow abnormalities, such as PLE and ascites, this imaging may be helpful for diagnosis and the planning of interventions and warrants further studies.
Key Points
• Intramesenteric dynamic contrast magnetic resonance lymphangiography (IM-DCMRL) is a new imaging technique to evaluate mesenteric lymphatic flow disorders such as ascites.
• IM-DCMRL is able to image lymphatic leaks in patients with ascites and protein losing enteropathy not seen with intranodal (IN-DCMRL) imaging.
Kaposiform lymphangiomatosis (KLA) is a rare lymphatic anomaly primarily affecting the mediastinum with high mortality rate. We present a patient with KLA and significant disease burden harboring a ...somatic point mutation in the Casitas B lineage lymphoma (CBL) gene. She was treated with MEK inhibition with complete resolution of symptoms, near‐complete resolution of lymphatic fluid burden, and remodeling of her lymphatic system. While patients with KLA have been reported to harbor mutations in NRAS, here we report for the first time a causative mutation in the CBL gene in a patient with KLA, successfully treated with Ras pathway inhibition.
Synopsis
Report of a patient with the rare lymphatic anomaly, Kaposiform lymphangiomatosis (KLA). CBL proto‐oncogene mutation was identified and she was successfully treated by targeting the MAP kinase pathway.
Identification of CBL mutation driving KLA.
Patient successfully treated with MEK inhibition.
Report of a patient with the rare lymphatic anomaly, Kaposiform lymphangiomatosis (KLA). CBL proto‐oncogene mutation was identified and she was successfully treated by targeting the MAP kinase pathway.
Protein-losing enteropathy (PLE) and plastic bronchitis are serious complications that occur after single-ventricle surgery. A lymphatic cause for these conditions has been proposed, but imaging ...correlation has not been reported. The objective of this study was to evaluate lymphatic abnormalities in patients after functional single-ventricle palliation compared with patients with non-single-ventricle congenital heart conditions using T2-weighted MR lymphangiography.
We retrospectively reviewed imaging data from 48 patients who underwent T2-weighted MR lymphangiography in our institution between May 1, 2012, and October 24, 2012. The patients were divided into four groups: patients who underwent superior cavopulmonary connection, patients who underwent total cavopulmonary connection, patients with total cavopulmonary connection and lymphatic complications, and patients with non-single-ventricle cardiac anomalies.
There were 38 patients with single ventricles in this study. The lymphatic abnormalities observed in these patients included thoracic duct dilation greater than 3 mm (31%), lymphangiectasia and lymphatic collateralization (78%), and tissue edema (86%). There were five patients with PLE, one patient with plastic bronchitis, and one patient with chronic chylous effusions and superior cavopulmonary connection. The patients with PLE and plastic bronchitis had statistically significant larger thoracic duct maximal diameters (median, 3.9 mm; range, 3-7.2 mm) than did the other patients with total cavopulmonary connection (p < 0.01). In the two-ventricle patient group, there were no abnormal lymphatic findings.
Lymphatic abnormalities are found in many patients after functional single-ventricle palliation. T2-weighted unenhanced MRI is capable of anatomic assessment of the lymphatic system in this patient population and has promise for guiding treatment in the future.
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