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.

Non-contrast MR lymphography of rare lymphatic abnormalities.

Detailed imaging of the lymphatic system often requires direct injection of contrast into lymph nodes which can be technically challenging, time consuming, and produce painful stimuli. We sought to describe the use of non-contrast MR lymphography (NCMRL) for normal controls and patients with a variety of rare disorders associated with lymphatic pathologies. Two control subjects and five affected patients (decompensated Fontan circulation, central conducting lymphatic abnormality, familial lymphedema and two with Gorham-Stout disease) were studied. NCMRL images were segmented in a semiautomated fashion and the major lymphatic channels and thoracic duct (TD) highlighted for identification. Adequate imaging was available for both controls and 4/5 affected patients; the youngest patient could not be imaged given patient motion. For the two controls, the TD was seen in the expected anatomic location. For the decompensated Fontan patient, there were numerous tortuous lymphatic channels, predominantly in the upper chest and neck. For the familial lymphedema patient, a TD was not identified; instead, peripheral lymphatic collaterals near the lateral chest walls. For the first Gorham- Stout patient, the TD was enlarged with large intrathoracic lymph collections. For the second Gorham-Stout patient, there were bilateral TD with lymph collections in vertebral bodies. Using NCMRL, we were able to image normal and abnormal lymphatic systems. An important learning point is the potential need for sedation for younger patients due to long image acquisition times and fine resolution of the structures of interest.

Postoperative chylothorax with a duplicated left-sided thoracic duct: a case report and review of the literature.

Postoperative chylothorax is a potentially lethal complication after esophagectomy. A 53-year-old woman underwent subtotal esophagectomy. The thoracic duct was resected due to swollen lymph nodes. Postoperative chylothorax was diagnosed but conservative treatment was ineffective. Lipiodol lymphangiography revealed leakage from a duplicated left-sided thoracic duct. Left-sided video-assisted thoracoscopic ligation of the left-sided thoracic duct was performed. Because anatomical variations in the thoracic duct contribute to refractory chylothorax, lymphangiography is useful in detecting the position of thoracic duct injury as well as any duct anomalies. Based on lymphangiography, left-sided video-assisted thoracoscopic surgery could be considered in case of left-sided thoracic duct injury.

A detailed pathway and termination of thoracic duct in a Japanese female cadaver with situs inversus totalis.

Although the thoracic duct (TD) requires special attention during thoracic surgery, to our knowledge, its detailed course in the situs inversus totalis (SIT) case has not been reported. We encountered an 86-year-old Japanese female cadaver with SIT during a student anatomical practice and examine the TD. The TD originated from the cisterna chyli at the level of the 2nd lumbar vertebra, ascended along with the left side of aorta and then passed behind the aortic arch on the right side of the esophagus. The TD turned right at the first thoracic vertebra and finally emptied into the basal portion of the right external jugular vein without branching. The present running pathway of the TD was approximately in the inverted position of the normal, but its connection site to the vein and manner was very rare and has not been reported to date. Therefore, this junctional anomaly may occur during the developmental period in SIT. Further anatomical and embryological studies are required, but this report provides useful morphogenetic information of the TD and lymphovenous junction in SIT.

Thoracic duct-to-vein anastomosis for the management of thoracic duct outflow obstruction in newborns and infants: a CASE series.

BACKGROUND: Thoracic duct (TD) outflow obstruction causes high morbidity and mortality in newborns. It can be congenital/idiopathic or acquired (secondary to central venous thrombosis or injury during cardiothoracic surgery). Re-routing the TD to the venous system by microsurgical techniques to restore lymphatic flow is a potential surgical solution. We present a series of newborns and infants who underwent thoracic duct-to-vein anastomosis (TDVA) to restore TD outflow. MATERIALS AND METHODS: A retrospective review of all TDVA September 2015-March 2019 was performed. All patients underwent extensive pre-operative imaging evaluation by dynamic MRI and fluoroscopic lymphangiography. The TDVAs were done under high-power microscopy. RESULTS: Eight patients underwent TDVA. Age at surgery was 1 to 9 months. Four patients had a history of cardiac surgery (one with complete thrombosis of the central venous system), one patient had a history of ECMO and thrombosis of the SVC, and three patients had a history of fetal hydrothorax and non-immune hydrops. Six patients had a successful TDVA with restoration of the lymphatic flow through the TD and clinical improvement. Two patients had a technically adequate TDVA but without improvement of the flow due to persistently high central venous pressure. Five patients remain alive, two patients died from complications of the lymphatic disorder, and one patient died from an unrelated cause. CONCLUSIONS: Patients with congenital or acquired TD outlet obstruction for whom no improvement is achieved by non-surgical interventions may benefit from TDVA. A thorough understanding of the anatomy and physiology of each patient is critical for the success of the operation. LEVEL OF EVIDENCE: Level IV.

Imaging of central lymphatic abnormalities in Noonan syndrome.

BACKGROUND: Children with Noonan syndrome are known to have increased risk for lymphatic disorders, the extent and nature of which are poorly understood. OBJECTIVE: Our objective was to describe the imaging findings of the central lymphatic abnormalities in children with Noonan syndrome who underwent central lymphatic imaging. MATERIALS AND METHODS: We conducted a single-center retrospective review of all children with a confirmed history of Noonan syndrome who presented for lymphatic imaging over a 5-year period. Imaging evaluation was performed on unenhanced T2-weighted (T2-W) imaging, dynamic-contrast MR lymphangiography or conventional lymphangiography. Two readers evaluated the imaging in consensus for the distribution of fluid on T2-W imaging and for lymphatic flow of intranodal contrast agent and thoracic duct abnormalities on dynamic-contrast MR lymphangiography and conventional lymphangiography. We performed a chart review for clinical history and outcomes. RESULTS: We identified a total of 10 children, all but one of whom had congenital heart disease. Presenting symptoms included chylothorax (n=9) and ascites (n=1). Nine had T2-W imaging, seven had dynamic-contrast MR lymphangiography, and seven had conventional lymphangiography. All with T2-W imaging had pleural effusions. On both dynamic-contrast MR lymphangiography and conventional lymphangiography, perfusion to the lung was seen (n=6), with intercostal flow also seen on dynamic-contrast MR lymphangiography (n=6). The thoracic duct was not present in three children and the central thoracic duct was not present in three. A double thoracic duct was seen in two children. CONCLUSION: Children with Noonan syndrome and clinical evidence of lymphatic dysfunction have central lymphatic abnormalities characterized by retrograde intercostal flow, pulmonary lymphatic perfusion, and thoracic duct abnormalities.

Lymphaticovenous bypass of the thoracic duct for the treatment of chylous leak in central conducting lymphatic anomalies.

BACKGROUND: Central conducting lymphatic anomalies (CCLA) may cause chylous leaks and protein-losing enteropathy (PLE) owing to dysfunction of the central lymphatic channels. Most of the treatment strategies for these conditions are palliative and provide transient improvement. METHODS: We treated 14 patients with intractable chylous leak and/or PLE using a novel technique of lymphaticovenous bypass of the terminal portion of the thoracic duct. Chylous leaks occurred in multiple different anatomic sites. All patients had CCLA and failure of thoracic duct emptying demonstrated by preoperative intranodal lymphangiography. RESULTS: Five patients had complete resolution of symptoms, and two patients had partial improvement. There were no major complications. Of 5 patients with PLE, only one improved after lymphaticovenous bypass. Repeat traditional lymphangiography was performed in 4 patients who did not improve, demonstrating patency of the bypass in all cases with persistent sluggish drainage. One patient had repeat MR lymphangiography that did not show the thoracic duct well. CONCLUSIONS: Bypass of the terminal thoracic duct is a novel procedure that offers improvement and a chance of cure for some patients with devastating manifestations of CCLA who lack other effective therapeutic options. LEVEL OF EVIDENCE: IV.

Lymphovenous Anastomoses Between Thoracic Duct and Azygos Vein in a Human Cadaver: A Case Report.

OBJECTIVE: The study adds valuable information regarding lymphovenous communications between the thoracic duct and the azygos vein, which are very rarely discovered during anatomical dissections and very few cases have been mentioned worldwide. A detailed description of our findings and a brief review of the relevant literature are also provided. CASE REPORST: In the current study, two sizeable obliquely directed lymphovenous anastomoses between the thoracic duct and the azygos vein at the midportion of the mediastinum are described in the same cadaver. CONCLUSION: The existence of such anastomoses in humans, as well in animals, is a scientific issue under debate. Cases of rapid cancer spread could be potentially explained by the likely presence of the abovementioned communications.

Endolymphatic Interventions for the Treatment of Chylothorax and Chylous Ascites in Neonates: Technical and Clinical Success and Complications.

BACKGROUND: The aim of this study was to report the technical and clinical success of performing minimally invasive endolymphatic embolization in neonates presenting with a chylothorax or chylous ascites. METHODS: Three neonates, 2 males and 1 female, with a mean age of 28 days (range: 19-39 days) presented with a chylothorax or chylous ascites that was refractory to conservative management. All 3 patients (1 previously reported) underwent intranodal lymphangiography, followed by thoracic duct embolization, with 1 patient undergoing additional sclerosis of the retroperitoneal abdominal lymphatics. RESULTS: Lymphangiography, thoracic duct embolization, and sclerosis of the retroperitoneal abdominal lymphatics were technically successful. The chylothorax resolved in both the patients. Persistent chylous ascites was noted after treatment which resolved after surgical placement of a vicryl mesh and fibrin sealant. One major complication occurred with nontarget embolization of glue into the lungs requiring embolectomy. CONCLUSIONS: Thoracic duct and retroperitoneal abdominal lymphatic embolization can be performed in neonates. Resolution of chylothorax was seen in 2 patients (one previously reported) after embolization, whereas 1 patient with chylous ascites required surgical management after endolymphatic intervention.

Spontaneous retropharyngeal and mediastinal thoracic duct cyst in an infant with respiratory distress.

Thoracic duct cysts (TDC) within the retropharyngeal space and mediastinum are exceedingly rare lesions, with the majority related to trauma or neoplasm. We describe a case of an otherwise healthy 8-month-old boy who presented with severe respiratory distress, which was found to be caused by a large, spontaneous TDC occupying most the retropharyngeal and mediastinal space. To our knowledge, this is the youngest patient to date presenting with TDC. Ultimately, his TDC was completely resolved with sclerotherapy, however the patient's age and size presented unique challenges to his medical management, which we describe below.

Complete right- and left-sided thoracic ducts associated with aberrant left vertebral artery: unreported case with surgical implications.

Anatomy is the keystone to an appropriate understanding of surgical and radiological sciences. Here the authors report on a rare case of complete right- and left-sided thoracic ducts (TDs) associated with aberrant left-vertebral artery (LVA) arising from the aortic arch. The TDs originated from right and left cisterna chyli and terminated separately close to the left venous angle. Superior to the aortic arch, the TDs showed different relationships to the LVA; the right TD was ventral, while the left was dorsal in position. This report is associated with other variations detailed below, and may have important implications in cervicothoracic surgery. (Folia Morphol 2018; 77, 1: 156-160).

Polydom Is an Extracellular Matrix Protein Involved in Lymphatic Vessel Remodeling.

RATIONALE: Lymphatic vasculature constitutes a second vascular system essential for immune surveillance and tissue fluid homeostasis. Maturation of the hierarchical vascular structure, with a highly branched network of capillaries and ducts, is crucial for its function. Environmental cues mediate the remodeling process, but the mechanism that underlies this process is largely unknown. OBJECTIVE: Polydom (also called Svep1) is an extracellular matrix protein identified as a high-affinity ligand for integrin α9ß1. However, its physiological function is unclear. Here, we investigated the role of Polydom in lymphatic development. METHODS AND RESULTS: We generated Polydom-deficient mice. Polydom-/- mice showed severe edema and died immediately after birth because of respiratory failure. We found that although a primitive lymphatic plexus was formed, it failed to undergo remodeling in Polydom-/- embryos, including sprouting of new capillaries and formation of collecting lymphatic vessels. Impaired lymphatic development was also observed after knockdown/knockout of polydom in zebrafish. Polydom was deposited around lymphatic vessels, but secreted from surrounding mesenchymal cells. Expression of Foxc2 (forkhead box protein c2), a transcription factor involved in lymphatic remodeling, was decreased in Polydom-/- mice. Polydom bound to the lymphangiogenic factor Ang-2 (angiopoietin-2), which was found to upregulate Foxc2 expression in cultured lymphatic endothelial cells. Expressions of Tie1/Tie2 receptors for angiopoietins were also decreased in Polydom-/- mice. CONCLUSIONS: Polydom affects remodeling of lymphatic vessels in both mouse and zebrafish. Polydom deposited around lymphatic vessels seems to ensure Foxc2 upregulation in lymphatic endothelial cells, possibly via the Ang-2 and Tie1/Tie2 receptor system.

Anatomical Variations of the Thoracic Duct: A Preliminary Report in Adult and Fetal Specimens.

The study aim is to evaluate anatomical variations of the thoracic duct using a specialized sequential injection procedure. The different types, frequencies, and anatomical topography were recorded and evaluated using 12 adult and 16 fetus specimens. By employing a perfusion pump device, cadavers were sequentially perfused with acrylic colored latex first through the internal marginal vein, then the thoracic duct at the interazygous-aortic recess, and finally through the posterior tibial artery. After perfusion, thoracic ducts were identified, partially dissected, and cadavers fixed by soaking in an aqueous solution of 5% formalin (v/v). Finally, further dissection and detailed photography were performed. Plexus shapes at different levels were clearly evident in 80% of the adult specimens. Whereas the presence of the cisterna chyli was detected in 100% of fetuses as an ampule dilatation at the beginning of the thoracic duct, in only one adult specimen was a dilatation found at the lumbar lymphatic trunk level. Functionally it is not known whether these modified anatomical features (plexus shapes) have served to compensate (as a derivative pathway) for lymphatic hypertension in life as a reflection of lymphatic system challenges and subsequent growth in the adult specimens.

Anatomic variability of the thoracic duct in pediatric patients with complex congenital heart disease.

OBJECTIVE: Thoracic duct mass ligation (TDML) through a right thoracotomy (RT), regardless of the side of the pleural effusion, is a standard procedure for chylothorax that is refractory to medical treatment. This procedure may be unsuccessful in patients with complex congenital heart disease, which necessitates additional left thoracotomy (LT) for left periaortic mass ligation. We hypothesized that failure of the right-sided approach is attributable to the anatomic variation of the path of the thoracic duct. METHODS: Of the children who underwent surgery for congenital heart disease between 1992 and 2014, a total of 70 of 8880 (0.8%) underwent TDML by RT (n = 57) or LT (n = 13; LT after RT in 10, and primary LT in 3). RESULTS: Persistent chylothorax was successfully resolved in 65 patients (65 of 70; 93%) within 15 days (2-79 days) after the first or second TDML; 5 patients died with a chest-tube(s) in situ. After excluding mortality without chest-tube removal, we sought to identify the risk factor(s) necessitating LT in 65 patients (RT group: 54; LT group: 11). On logistic regression analysis, the LT group was more likely to have dextrocardia (odds ratio: 6.38; 95% confidence interval: 1.09-37.25; P = .04). The incidence of abnormal atrial situs, great arterial malposition, right descending thoracic aorta, and bilateral superior vena cavae were comparable in the 2 groups. CONCLUSIONS: The path of the thoracic duct may vary in pediatric patients with complex congenital heart disease. Left periaortic mass ligation should be considered in patients with chylothoraces that persist after the right-sided approach, especially in patients with dextrocardia.

Oesophageal cancer with an aberrant right subclavian artery accompanied by a thoracic duct anomaly.

Recognizing the pathway of thoracic duct during oesophagectomy is important to prevent from postoperative chylothorax. In this study, we describe 4 cases with anormalies of the thoracic duct found during oesophagectomy for oesopahageal cancer. Each of the 4 cases showed different patterns of anomaly of the thoracic duct, and all the 4 cases were associated with an aberrant right subclavian artery (ARSA). Therefore, careful inspection of the thoracic ducts is strongly recommended during oesophagectomy especially if an ARSA has been identified.