Anatomy of the Thoracic Duct

Impact of Thoracic Duct Resection on Long-Term Survival After Esophagectomy: Individual Patient Data Meta-analysis

BACKGROUND

Radical esophagectomy, including thoracic duct resection (TDR), has been proposed to improve regional lymphadenectomy and possibly reduce the risk of locoregional recurrence. However, because of its impact on immunoregulation, some authors have expressed concerns about its possible detrimental effect on long-term survival. The purpose of this review was to assess the influence of TDR on long-term survival.

PATIENTS AND METHODS

PubMed, MEDLINE, Scopus, and Web of Science databases were searched through 15 March 2024. Overall survival (OS), cancer specific survival (CSS), and disease-free survival (DFS) were primary outcomes. Restricted mean survival time difference (RMSTD), risk ratio (RR), standardized mean difference (SMD), and 95% confidence intervals (CI) were used as pooled effect size measures. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology was employed to evaluate the certainty of evidence.

RESULTS

The analysis included six studies with 5756 patients undergoing transthoracic esophagectomy. TDR was reported in 49.1%. Patients' ages ranged from 27 to 79 years and 86% were males. At 4-year follow-up, the multivariate meta-analysis showed similar results for the comparison noTDR versus TDR in term of OS [- 0.8 months, 95% confidence interval (CI) - 3.1, 1.3], CSS (0.1 months, 95% CI - 0.9, 1.2), and DFS (1.5 months, 95% CI - 2.6, 5.5). TDR was associated with a significantly higher number of harvested mediastinal lymph nodes (SMD 0.57, 95% CI 0.01-1.13) and higher risk of postoperative chylothorax (RR = 1.32; 95% CI 1.04-2.23). Anastomotic leak and pulmonary complications were comparable.

CONCLUSIONS

TDR seems not to improve long-term OS, CSS, and DFS regardless of tumor stage. Routine TDR should not be routinely recommended during esophagectomy.

Lymphatic Interventions in Congenital Heart Disease

Lymphatic disorders in congenital heart disease can be broadly classified into chest compartment, abdominal compartment, or multicompartment disorders. Heavily T2-weighted noninvasive lymphatic imaging (for anatomy) and invasive dynamic contrast magnetic resonance lymphangiography (for flow) have become the main diagnostic modalities of choice to identify the cause of lymphatic disorders. Selective lymphatic duct embolization (SLDE) has largely replaced total thoracic duct embolization as the main lymphatic therapeutic procedure. Recurrence of symptoms needing repeat interventions is more common in patients who underwent SLDE. Novel surgical and transcatheter thoracic duct decompression strategies are promising, but long-term follow-up is critical and eagerly awaited.

Impact of thoracic duct resection during radical esophagectomy on oncological and survival outcomes: Systematic review

Practice is variable in the inclusion or exclusion of the thoracic duct (TD) as part of the resected specimen and associated lymphadenectomy in radical esophagectomy for esophageal cancer. While some surgeons believe that the removal of TD-associated nodes may improve radicality and survival, others suggest this represents systemic disease and resection may increase morbidity without survival benefit. A systematic review was performed up to March 2023 using the search terms 'esoph∗' AND 'thoracic duct' for relevant articles which compared thoracic duct preservation (TDP) to resection (TDR) in esophagectomy for esophageal cancer. Included studies were required to report relevant oncological outcomes including at least one of overall survival (OS), disease free survival (DFS) and nodal yield. Seven cohort studies were included in data synthesis, including data for 5926 patients. None of the reported studies were randomised controlled trials. All studies originated from Japan or South Korea with almost exclusively squamous cell-type cancer. Nodal yield was higher in TDR groups. TDR was equivalent or inferior to TDP with reference to clinical outcomes (length of stay, morbidity, mortality). A single study reported increased OS in the TDR group while the remaining studies reported no significant difference. Overall study quality was moderate to poor. While an increased nodal yield may be associated with TDR, this may also be associated with higher morbidity, and currently available data does not suggest any survival benefit.

Thoracic duct disruption without lymphangiographic thoracic duct visualization for refractory chylothorax: A case report

Percutaneous treatments, including thoracic duct embolization (TDE) and thoracic duct disruption (TDD), are reportedly effective and safe alternatives to surgical thoracic duct ligation for refractory chylothorax. When catheterization of the thoracic duct is impossible, TDD can be performed as long as the thoracic duct can be opacified by lymphangiography. However, no report has described percutaneous treatment when the thoracic duct cannot be visualized. In this case, TDE was not feasible because intranodal lymphangiography failed to opacify the thoracic duct: cannulation was not achieved. Therefore, we aimed to disrupt the thoracic duct by puncturing the retrocrural area where it was anatomically suspected to be located. Chylothorax improved thereafter. In cases without lymphangiographic thoracic duct visualization, TDD by puncturing the retrocrural space might improve refractory chylothorax.

Thoracic duct cannulation during left internal jugular vein cannulation: A case report

BACKGROUND

Central venous catheter insertion is an invasive procedure that can cause complications such as infection, embolization due to air or blood clots, pneumothorax, hemothorax, and, rarely, chylothorax due to damage to the thoracic duct. Herein, we report a case of suspected thoracic duct cannulation that occurred during left central venous catheter insertion. Fortunately, the patient was discharged without any adverse events related to thoracic duct cannulation.

CASE SUMMARY

A 46-year-old female patient presented at our department to undergo cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. During anesthesia, we decided to insert a central venous catheter through the left internal jugular vein because the patient already had a chemoport through the right central vein. During the procedure, blood reflux was observed when the needle tip was not within the ultrasound field of view. We did not try to find the tip; however, a guide wire and a central venous catheter were inserted without any resistance. Subsequently, when inducing blood reflux from the distal port of the central venous catheter, only clear fluid, suspected to be lymphatic fluid, was regurgitated. Further, chest X-ray revealed an appearance similar to that of the path of the thoracic duct. Given that intravenous fluid administration was not started and no abnormal fluid collection was noted on preoperative chest X-ray, we suspected thoracic duct cannulation.

CONCLUSION

It is important to use ultrasound to confirm the exact position of the needle tip and guide wire path.

A chyle leak following a tumorectomy and an axillary sentinel lymph node dissection: Case report

A chyle leak following a tumorectomy is a rare complication of surgery for breast cancer. We report a case of chylous leakage after axillary sentinel lymph node dissection. A 78-year-old woman with a left breast invasive ductal carcinoma underwent a breast-conserving surgery and had two sentinel lymph nodes removed. Ten days after surgery she came back with a swelling the left breast and the axilla, the drainage fluid was "milky". She underwent a second surgery for positive margins, during which time we did a mass ligature in the axilla and placed a drain that was remove when it wasn't productive anymore.

Near-infrared fluorescence imaging of thoracic duct in minimally invasive esophagectomy

Chylothorax is a serious complication after esophagectomy and there are unmet needs for new intraoperative navigation tools to reduce its incidence. The aim of this study is to explore the feasibility and effectiveness of near-infrared fluorescence imaging (NIR-FI) with indocyanine green (ICG) to identify thoracic ducts (TDs) and chyle leakage during video-assisted thoracoscopic esophagectomy. We recruited 41 patients who underwent thoraco-laparoscopic minimally invasive esophagectomy (MIE) for esophageal cancer in this prospective, open-label, single-arm clinical trial. ICG was injected into the right inguinal region before operations, after which TD anatomy and potential chyle leakage were checked under the near-infrared fluorescence intraoperatively. In 38 of 41 patients (92.7%) using NIR-FI, TDs were visible in high contrast. The mean signal-to-background ratio (SBR) value of all fluorescent TDs was 3.05 ± 1.56. Fluorescence imaging of TDs could be detected 0.5 hours after ICG injection and last up to 3 hours with an acceptable SBR value. The optimal observation time window is from about 1 to 2 hours after ICG injection. Under the guidance of real-time NIR-FI, three patients were found to have chylous leakage and the selective TD ligations were performed intraoperatively. No patient had postoperative chylothorax. NIR-FI with ICG can provide highly sensitive and real-time assessment of TDs as well as determine the source of chyle leakage, which might help reduce TD injury and direct selective TD ligation. It could be a promising navigation tool to reduce the incidence of chylothorax after minimally invasive esophagectomy.

The cisterna chyli: a systematic review of definition, prevalence, and anatomy

The cisterna chyli is a lymphatic structure found at the caudal end of the thoracic duct that receives lymph draining from the abdominal and pelvic viscera and lower limbs. In addition to being an important landmark in retroperitoneal surgery, it is the key gateway for interventional radiology procedures targeting the thoracic duct. A detailed understanding of its anatomy is required to facilitate more accurate intervention, but an exhaustive summary is lacking. A systematic review was conducted, and 49 published human studies met the inclusion criteria. Studies included both healthy volunteers and patients and were not restricted by language or date. The detectability of the cisterna chyli is highly variable, ranging from 1.7 to 98%, depending on the study method and criteria used. Its anatomy is variable in terms of location (vertebral level of T10 to L3), size (ranging 2-32 mm in maximum diameter and 13-80 mm in maximum length), morphology, and tributaries. The size of the cisterna chyli increases in some disease states, though its utility as a marker of disease is uncertain. The anatomy of the cisterna chyli is highly variable, and it appears to increase in size in some disease states. The lack of well-defined criteria for the structure and the wide variation in reported detection rates prevent accurate estimation of its natural prevalence in humans.

Invasive treatment of persistent postoperative chylothorax secondary to thoracic duct variation injury: Two case reports and literature review

RATIONALE

Postoperative chylothorax is a rare complication after pulmonary resection. Thoracic duct variations may play a key role in postoperative chylothorax occurrence and make treatment difficult. No studies in the literature have reported the successful treatment of chylothorax second to thoracic duct variation by lipiodol-based lymphangiography.

PATIENT CONCERNS

A 63-year-old male and a 28-year-old female with primary lung adenocarcinoma were treated by video-assisted thoracoscopic cancer resection, and suffered postoperative chylothorax. Conservative treatment was ineffective, including nil per os, persistent thoracic drainage, fatty food restriction, and somatostatin administration.

DIAGNOSIS

Postoperative chylothorax.

INTERVENTIONS

Patients received lipiodol-based lymphangiography under fluoroscopic guidance. Iatrogenic injuries were identified at thoracic duct variations, including an additional channel in case 1 and the lymphatic plexus instead of the thoracic duct in case 2.

OUTCOMES

Thoracic duct variations were identified by lipiodol-based lymphangiography, and postoperative chylothorax was successfully treated by lipiodol embolizing effect.

LESSONS

Thoracic duct variations should be considered after the failure of conservative treatment for postoperative chylothorax secondary to pulmonary resection. Lipiodol-based lymphangiography is valuable for identifying the thoracic duct variations and embolizing chylous leakage.

Case report: Balloon compression for cervical chyle leakage post neck dissection

Postoperative chyle leakage (CL) is a rare but severe complication after neck dissection, and most patients with this complication can be treated conservatively. However, in patients with high-flow leakage, efficient and well-tolerated conservative treatment options are still lacking, and the treatments can be complicated. In this study, we report a case with CL of 1100 ml/day after neck dissection that was successfully treated by balloon compression.

An effective method to reduce lymphatic drainage post-lateral cervical lymph node dissection of differentiated thyroid cancer: a retrospective analysis

Background

Lymph or chyle leak (LL/CL) is severe complications after lateral cervical lymph node dissection (LLND), mainly due to iatrogenic injury of the lymphatic duct. Efficient and well-operated methods to reduce postoperative drainage are still lacking. This was a feasibility study to evaluate a new method of preventing LL/CL compared to conventional treatment.

Method

We retrospectively analyzed 20 consecutive patients who used the “pedicled omohyoid flap covering (POFC)” method during LLND from January 2019 to December 2021 in our center as an observation group. Another 20 consecutive patients used the conventional method during LLND in this period as a control group. The clinical and pathological features of the two groups were compared, and the related factors that affected postoperative lymphatic drainage were analyzed with Cox proportional hazards models.

Results

The drainage volume per 24 h and the incidence of LL/CL in the control group were both higher than that in the observation group (all P < 0.05), and the number of lymph nodes dissected in the IV region > 10 and the use of the POFC method were the independent risk factors that significantly affected the incidence of LL/CL post LLND (all P < 0.05).

Conclusions

POFC is a safe and useful method for reducing drainage and preventing LL/CL post-LLND, especially for patients with heavy metastasis of the lymph nodes in the IV region.

State-of-the-art imaging for lymphatic evaluation in children

The lymphatic system has been poorly understood and its importance neglected for decades. Growing understanding of lymphatic flow pathophysiology through peripheral and central lymphatic flow imaging has improved diagnosis and treatment options in children with lymphatic diseases. Flow dynamics can now be visualized by different means including dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL), the current standard technique to depict central lymphatics. Novel imaging modalities including intranodal, intrahepatic and intramesenteric DCMRL are quickly evolving and have shown important advances in the understanding and guidance of interventional procedures in children with intestinal lymphatic leaks. Lymphatic imaging is gaining importance in the radiologic and clinical fields and new techniques are emerging to overcome its limitations.

Intraoperative visualization of morphological patterns of the thoracic duct by subcutaneous inguinal injection of indocyanine green in esophagectomy for esophageal cancer

To prevent chylothorax after esophageal cancer surgery, it is important to recognize morphological patterns of the thoracic duct intraoperatively. The present study aimed to evaluate the safety and usefulness of near-infrared (NIR) fluorescence imaging with subcutaneous inguinal injection of indocyanine green (SII-ICG) to detect the thoracic duct during thoracoscopic esophagectomy for esophageal cancer. Patients (n = 16) who underwent thoracoscopic esophagectomy in the prone position with SII-ICG at Shinshu University Hospital between June 2020 and January 2022 were enrolled in the present study and retrospectively reviewed. Immediately prior to thoracoscopic esophagectomy, we injected 0.2-0.5 mg/kg ICG into the subcutaneous tissue in the bilateral inguinal region. The identification rate of the thoracic duct was 93.8% (n = 15), and the success rate of fluorescence using SII-ICG was 87.5% (n = 14). The visible thoracic ducts had four patterns: a typical pattern in 50% (n = 8), duplication pattern in 18.8% (n = 3), branching pattern in 12.5% (n = 2), and plexiform pattern in 12.5% (n = 2). In all cases, ICG fluorescence did not disappear and was visible during the thoracic surgery. No SII-ICG-related complications were observed. Intraoperative NIR fluorescence imaging of the thoracic duct using SII-ICG is a simple and safe method with very high detection sensitivity. This method can be a powerful tool for avoiding thoracic duct injuries during esophageal cancer surgery.

Targeting Lymphatics for Nanoparticle Drug Delivery

The lymphatics transport material from peripheral tissues to lymph nodes, where immune responses are formed, before being transported into systemic circulation. With key roles in transport and fluid homeostasis, lymphatic dysregulation is linked to diseases, including lymphedema. Fluid within the interstitium passes into initial lymphatic vessels where a valve system prevents fluid backflow. Additionally, lymphatic endothelial cells produce key chemokines, such as CCL21, that direct the migration of dendritic cells and lymphocytes. As a result, lymphatics are an attractive delivery route for transporting immune modulatory treatments to lymph nodes where immunotherapies are potentiated in addition to being an alternative method of reaching systemic circulation. In this review, we discuss the physiology of lymphatic vessels and mechanisms used in the transport of materials from peripheral tissues to lymph nodes. We then summarize nanomaterial-based strategies to take advantage of lymphatic transport functions for delivering therapeutics to lymph nodes or systemic circulation. We also describe opportunities for targeting lymphatic endothelial cells to modulate transport and immune functions.

In Vitro Evaluation of Acrylic Adhesives in Lymphatic Fluids-Influence of Glue Type and Procedural Parameters

To evaluate the embolic properties of different acrylic adhesive/iodized oil mixtures for lymphatic interventions. Polymerization of histoacryl (HA) (Bayer Healthcare) and glubran 2 (GL) (GEM) mixed with iodized oil (ratios 1:0–1:7) were investigated in lymphatic fluids with low and high triglyceride (low TG & high TG) contents. Static polymerization time and dynamic polymerization experiments with different volumes of glucose flush (1, 2 and 5 mL) were performed to simulate thoracic duct embolization. For both glues, static polymerization times were longer when the iodized oil content was increased and when performed in high TG lymphatic fluid. In the dynamic experiments, the prolongation of polymerization due to the oil content and TG levels was less pronounced for both glue types. Increased lymphatic flow rates decreased embolization times for low glue/oil ratios while preventing embolization for high glue/oil ratios. Higher glucose flush volumes increased occlusion times. Polymerization times of acrylic glue in a lymphatic fluid are prolonged by increasing the iodized oil concentration and triglyceride concentration as well as by using larger volumes of glucose flush. Increased lymphatic flow rates decrease embolization times for low glue/oil ratios and may prevent embolization for high glue/oil ratios.

Lymphatic Disorders in Patients With Single Ventricle Heart Disease

Lymphatic abnormalities in patients with single ventricle physiology can lead to early Fontan failure and severe Fontan complications, such as protein-losing enteropathy (PLE), plastic bronchitis (PB), chylothorax, and edema. Recent developments in lymphatic imaging and interventions have shed new light on the lymphatic dysfunction in this patient population and the role of the lymphatic circulation in PLE, PB, and chylothorax. In this study, we reviewed some of the latest developments in this field and discuss new treatment options for these patients.

Microsurgical Thoracic Duct Lymphovenous Bypass in the Adult Population

Thoracic duct occlusion can lead to devastating complications, resulting in recalcitrant chylothoraces, ascites, generalized lymphedema, metabolic derangement, and death. Lymphatic extravasation has traditionally been managed conservatively and, in recent years, using minimally invasive techniques, such as thoracic duct ligation and embolization. However, these measures are often limited in application and therapeutic success, resulting in chronically difficult conditions with few modalities available for definitive management. Advances in microsurgery have allowed for surgical treatment and resolution of peripherally-based lymphatic pathology, though microsurgical intervention to address central lymphatic abnormalities is scarcely described. This report is the first series detailing experiences utilizing microsurgical thoracic duct lymphovenous bypass in a refractory adult population with thoracic duct occlusion. Four patients successfully underwent the procedure, with three achieving complete resolution of symptoms. The fourth patient enjoyed partial resolution, though ubiquitous lymphatic deformities have conferred recurrent residual lower-extremity peripheral edema requiring future intervention. Postoperatively, patent anastomoses were confirmed under magnetic resonance lymphangiography. This series demonstrates the feasibility of microsurgical thoracic duct lymphovenous bypass as a promising technique in treating patients suffering from thoracic duct occlusion. This intervention is effective for recalcitrant chylothorax, chylous ascites, and generalized lymphedema, particularly when traditional and interventional radiological techniques are unsuccessful.

Anatomical study of the thoracic duct and its clinical implications in thoracic and pediatric surgery, a 70 cases cadaveric study

INTRODUCTION

Given the high variability and fragility of the thoracic duct, good knowledge of its anatomy is essential for its repair or to prevent iatrogenic postoperative chylothorax. The objective of this study was to define a site where the thoracic duct is consistently found for its ligation. The second objective was to define an anatomically safe surgical pathway to prevent iatrogenic chylothorax in surgery for aortic arch anomalies with vascular ring, through better knowledge of the anatomical relationships of the thoracic duct.

METHODS

Seventy adult formalin-fixed cadavers were dissected. The anatomical relationships of the thoracic duct were reported at the postero-inferior mediastinum, at levels T3 and T4.

RESULTS

The thoracic duct was consistently situated between the left anterolateral border of the azygos vein and the right border of the aorta between levels T9 and T10, whether it was simple, double, or plexiform. It was located medially, anteromedially, or posteriorly to the left subclavian artery in 51%, 21%, and 28% of the cases, respectively, at the level of T3. At T4, it was posteromedial in 27% of the cases or had no direct relationship with the aortic arch.

CONCLUSION

These results favor mass ligation of the thoracic duct at levels T9-T10 between the right border of the aorta and the azygos vein, eventually including the latter. To prevent iatrogenic postoperative chylothorax in aortic arch anomalies with vascular ring surgery, we recommend remaining strictly lateral to the left subclavian artery at the level of T3 to reach the aortic arch anomalies with vascular ring at T4.

Embolization or disruption of thoracic duct and cisterna chyli leaks post oesophageal cancer surgery should be first line management for ECCG-defined type III chyle fistulae

Chyle leakage from the thoracic duct or cisterna chyli is a relatively rare complication of oesophageal cancer surgery. The majority of cases settle with conservative measures, but high volume leaks may be refractory and result in significant morbidity and require intervention with reoperation or embolization. In the experience of this high-volume centre over the last decade, 3 (0.5%) patients required reoperation and ligation of the thoracic duct; for the so-called type III leaks, interventional radiological approaches were not considered. This article is built around two recent cases, where interventional radiology to embolize and disrupt complex fistulae was successfully performed. The lessons from this experience will change practice at this centre to initial lymphangiography with a view to embolization or disruption of thoracic duct and cisterna chyli leaks as first line therapy for type III chyle leaks, with surgery reserved for where this fails.

Management options for post-esophagectomy chylothorax

Chylothorax, although an uncommon complication of esophagectomy, is associated with high morbidity and mortality if not treated promptly. Consequently, knowledge of the thoracic duct (TD) anatomy is essential to prevent its inadvertent injury during surgery. If the TD is injured, early diagnosis and immediate intervention are of paramount importance; however, there is still no universal consensus about the management of post-operative chylothorax. With increasing advances in the spheres of interventional radiology and minimally invasive surgery, there are now several options for managing TD injury. We review this topic in detail to provide a comprehensive and practical overview to help surgeons manage this challenging complication. In particular, we discuss an appropriate step-up approach to prevent the morbidity associated with open surgery as well as the metabolic, nutritional, and immunological disorders that accompany a prolonged illness.

Chyle leakage after axillary node sampling in a patient with breast cancer: a case report

Background

Chyle leakage is a well-known complication after thoracic surgery, such as esophagectomy, cardiac surgery, mediastinal lymph node dissection, and neck surgery. However, chyle leakage is a rare complication after dissections of the lateral or subclavian axillary nodes for breast surgery. It is particularly unusual for chyle leakage to occur after minimally invasive dissection of the axillary nodes. Most cases of chyle leakage subside with conservative management, but some cases require surgery.

Case report

An 80-year-old woman had invasive lobular cancer of the left breast (cT1 [1.7 cm], cN0, M0) for which she underwent breast-conservative surgery and biopsy of an axillary sentinel lymph node. Because two of the three sentinel lymph nodes tested positive for cancer, seven lateral axillary lymph nodes (level I) were subsequently removed for the additional sampling. On postoperative day 11, the patient visited our outpatient clinic because of swelling in her left axillary region and breast. Centesis of the axilla yielded 670 mL of milky fluid, which suggested chyle leakage. We commenced the conservative management at first; however, the persistent leakage made us perform the surgical management. The operation was not only ligating the opening of the chyle duct but needed total mastectomy because the postoperative pathology report showed invasive lobular carcinoma; the nipple and the caudal surgical margin of the lumpectomy were positive for cancer. The patient agreed to our recommendation of total mastectomy and surgical management of the chyle leakage. Ligation of the opening completely resolved the chylous discharge.

Conclusion

We here report a case of large-volume leakage of chyle after sampling dissection of the lateral axillary lymph nodes for left breast cancer; the leakage persisted despite the standard conservative therapy but was resolved after surgical treatment. Chyle leakage can occur even after minimally invasive dissection of the axillary nodes.

Integrating Biological Advances Into the Clinical Management of Breast Cancer Related Lymphedema

Breast cancer-related lymphedema (BCRL) occurs in a significant number of breast cancer survivors as a consequence of the axillary lymphatics' impairment after therapy (mainly axillary surgery and irradiation). Despite the recent achievements in the clinical management of these patients, BCRL is often diagnosed at its occurrence. In most cases, it remains a progressive and irreversible condition, with dramatic consequences in terms of quality of life and on sanitary costs. There are still no validated pre-surgical strategies to identify individuals that harbor an increased risk of BCRL. However, clinical, therapeutic, and tumor-specific traits are recurrent in these patients. Over the past few years, many studies have unraveled the complexity of the molecular and transcriptional events leading to the lymphatic system ontogenesis. Additionally, molecular insights are coming from the study of the germline alterations involved at variable levels in BCRL models. Regrettably, there is a substantial lack of predictive biomarkers for BCRL, given that our knowledge of its molecular milieu remains extremely puzzled. The purposes of this review were (i) to outline the biology underpinning the ontogenesis of the lymphatic system; (ii) to assess the current state of knowledge of the molecular alterations that can be involved in BCRL pathogenesis and progression; (iii) to discuss the present and short-term future perspectives in biomarker-based patients' risk stratification; and (iv) to provide practical information that can be employed to improve the quality of life of these patients.

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.

Anatomical variations in distal portion of the thoracic duct-A systematic review

The objective of this study was to identify and analyze the anatomical variations in the termination of the thoracic duct (TD) in cadavers or patients by anatomical dissections and surgical or radiological procedures for better knowledge of the interindividual variations through a systematic review. The search strategy included PubMed and reference tracking. Studies were identified by searching the electronic Medline databases. The search terms included "TD," "Jugular Vein," "Subclavian Vein," or "Cervical," and the protocol used is reported herein. These search results yielded 20 qualitative review articles out of the 275 articles consulted. We collected all the important data from these 20 articles with 1,352 TD analyzed by varying sources in our search. Regarding the characteristics of the studies and the anatomy of the TD, the results were heterogeneous. The TD most commonly terminates in the internal jugular vein in 54.05% of cases (95% confidence interval [CI]: 54.03; 54.07), in the jugular-venous angle in 25.79% (95% CI: 25.77; 25.81), and in the subclavian vein in 8.16% of cases (95% CI: 8.14;8.18). Other terminations were found in 12% of cases. This systematic review provided an overview of the variations in the distal portion of the TD. This study can be helpful for surgeons in selecting the most appropriate methods to achieve successful surgical results and avoid complications, such as chylothorax; it also offers detailed information on the cervical termination of the TD in new diagnostic and therapeutic methods involving the TD. Clin. Anat. 32:99-107, 2019. © 2019 Wiley Periodicals, Inc.

Bilateral Chylothorax as a Unique Presentation of Pancreaticobiliary or Upper Gastrointestinal Cancer

Chylothorax presents as exudate with lymphocytic predominance and high triglyceride-low LDH levels, usually due to a traumatic disruption of the thoracic duct, possibly iatrogenic. Other causes include malignancy, sarcoidosis, goiter, AIDS, or tuberculosis. Here we present a case of a 66-year-old male who came in with cough and shortness of breath for few weeks. A week earlier, at an ED visit, he was diagnosed with pneumonia based on CT angiogram of the chest without contrast that showed bilateral pleural effusion and bilateral pulmonary infiltrates. The CT-guided placement of bilateral chest tube drained 1160 cc of creamy yellow fluid on the right and 1200 cc of creamy yellow fluid on the left. CT chest/abdomen/pelvis showed bilateral ground-glass opacities within the lungs and possible bony metastasis. A whole-body bone scan showed multiple bony metastatic lesions throughout the skeleton. IR guided bone biopsy suggested upper GI or pancreaticobiliary cancer. Venous ultrasound with Doppler of left upper extremity showed findings suggestive of a nonocclusive DVT of proximal/mid left subclavian vein which is difficult to compress. Eventually, malignancy-related DVT of the left subclavian/brachiocephalic vein was identified as the possible etiology for the bilateral chylothorax.

Therapeutic delivery to the peritoneal lymphatics: Current understanding, potential treatment benefits and future prospects

The interest in approaches to deliver therapeutics to the lymphatic system has increased in recent years as the lymphatics have been discovered to play an important role in a range of disease states such as cancer metastases, inflammatory and metabolic disease, and acute and critical illness. Therapeutic delivery to lymph has the potential to enhance treatment of these conditions. Currently much of the existing data explores therapeutic delivery to the lymphatic vessels and nodes that drain peripheral tissues and the intestine. Relatively little focus has been given to understanding the anatomy, function and therapeutic delivery to the peritoneal lymphatics. Gaining a better understanding of peritoneal lymphatic structure and function would contribute to the understanding of disease processes involving these lymphatics and facilitate the development of delivery systems to target therapeutics to the peritoneal lymphatics. This review explores the basic anatomy and ultrastructure of the peritoneal lymphatics system, the lymphatic drainage pathways from the peritoneum, and therapeutic and delivery system characteristics (size, lipophilicity and surface properties) that favour lymph uptake and retention after intraperitoneal delivery. Finally, techniques that can be used to quantify uptake into peritoneal lymph are outlined, providing a platform for future studies.

The Visibility of the Terminal Thoracic Duct Into the Venous System Using MR Thoracic Ductography with Balanced Turbo Field Echo Sequence

RATIONALE AND OBJECTIVES

Magnetic resonance thoracic ductography (MRTD) with balanced turbo field echo (bTFE) can visualize both the thoracic duct and its surrounding vessels. This study aimed to investigate the visibility of the terminal thoracic duct into the venous system in the subclavian region using MRTD with bTFE.

MATERIALS AND METHODS

MRTD was performed with bTFE as a preoperative workup comprising respiratory gating on a 1.5-T magnetic resonance system for patients with esophageal cancer. The portion and the number of terminal thoracic ducts into the venous system and preterminal branching in the left subclavian region were assessed using MRTD in 132 patients. The confidence level of the visibility using MRTD was also evaluated.

RESULTS

The most frequent terminal portion of the thoracic duct was the jugulovenous angle (92 patients, 69.7%), followed by the subclavian vein (27 patients, 20.5%) and the internal jugular vein (8 patients, 6.1%). Four patients also exhibited double entry of the thoracic duct into the venous system. The preterminal branching was single in 96 patients (72.7%) and multiple in 36 patients (27.3%). The confidence level of the visibility of the thoracic duct using MRTD was absolutely certain in 112 patients (84.8%) and was somewhat certain in 20 patients (15.2%).

CONCLUSIONS

MRTD with bTFE is a robust imaging modality to visualize the terminal portion of the thoracic duct into the venous system in the subclavian region.

Lymphatic Pump Manipulation in Patients with Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) show a persistent local and systemic inflammatory pattern which stimulates negative remodeling of the airways. Globally, chronic respiratory disease is the third leading cause of death. One of the rehabilitative strategies used to improve the symptoms of COPD patients is the use of lymphatic pump manipulation; this procedure aims to reduce the concentration of pro-inflammatory substances. However, research results relating to this technique are contradictory. This article reviews the mechanisms that determine lymphatic flow, lymphatic lung anatomy, and the lymphatic response to respiratory pathology. Also highlighted is the manual approach to the mediastinum which can be used to improve the lymphatic and inflammatory response in COPD. Finally, new manual strategies have been discussed with which lymphatic flow in patients with COPD can be improved.

A radio-anatomical correlation study of the cisterna chyli

Surgical laparoscopic procedures in the retroperitoneal and supramesocolic spaces are increasingly frequent. There is a high risk of iatrogenic intraoperative injury of the retroperitoneal lymphatic structures during these procedures. A precise understanding of the anatomy of the thoracic duct (TD) and the cisterna chyli (CC) is essential for safe surgical procedures in this area. However, routine imaging procedures rarely and often incorrectly visualize the CC. The objective of this study was to evaluate the feasibility of a retrograde injection of the TD to fill the CC with a contrast agent in 16 human cadavers. Both magnetic resonance lymphography (MRI) and computed tomography (CT) studies could be performed on the same anatomical specimen, using a contrast medium which hardened, allowing gross dissection. MRI and CT detectability were evaluated, and imaging results were compared with the anatomical dissection. The CC of 12/16 cadavers were successfully injected, and four were unsuccessful due to technical difficulties, showing the effectiveness of the method. This technique can improve understanding of the anatomy of the TD and CC and provides an original option to study the complex anatomy of these structures by correlating precise cadaveric dissections with cross-sectional imaging.

The anatomy and physiology of the terminal thoracic duct and ostial valve in health and disease: potential implications for intervention

The thoracic duct (TD) transports lymph drained from the body to the venous system in the neck via the lymphovenous junction. There has been increased interest in the TD lymph (including gut lymph) because of its putative role in the promotion of systemic inflammation and organ dysfunction during acute and critical illness. Minimally invasive TD cannulation has recently been described as a potential method to access TD lymph for investigation. However, marked anatomical variability exists in the terminal segment and the physiology regarding the ostial valve and terminal TD is poorly understood. A systematic review was conducted using three databases from 1909 until May 2017. Human and animal studies were included and data from surgical, radiological and cadaveric studies were retrieved. Sixty-three articles from the last 108 years were included in the analysis. The terminal TD exists as a single duct in its terminal course in 72% of cases and 13% have multiple terminations: double (8.5%), triple (1.8%) and quadruple (2.2%). The ostial valve functions to regulate flow in relation to the respiratory cycle. The patency of this valve found at the lymphovenous junction opening, is determined by venous wall tension. During inspiration, central venous pressure (CVP) falls and the valve cusps collapse to allow antegrade flow of lymph into the vein. During early expiration when CVP and venous wall tension rises, the ostial valve leaflets cover the opening of the lymphovenous junction preventing antegrade lymph flow. During chronic disease states associated with an elevated mean CVP (e.g. in heart failure or cirrhosis), there is a limitation of flow across the lymphovenous junction. Although lymph production is increased in both heart failure and cirrhosis, TD lymph outflow across the lymphovenous junction is unable to compensate for this increase. In conclusion the terminal TD shows marked anatomical variability and TD lymph flow is controlled at the ostial valve, which responds to changes in CVP. This information is relevant to techniques for cannulating the TD, with the aid of minimally invasive methods and high resolution ultrasonography, to enable longitudinal physiology and lymph composition studies in awake patients with both acute and chronic disease.

Anatomical study of the left superior mediastinal lymphatics for tracheal branches of left recurrent laryngeal nerve-preserving mediastinoscope-assisted surgery in esophageal cancer

PURPOSE

Curative treatment of esophageal cancer requires meticulous superior mediastinal lymphadenectomy, in addition to esophagectomy, because superior mediastinal lymph node metastases are common in esophageal cancer. When preserving the tracheal branches of the left recurrent laryngeal nerve (RLN), good anatomical understanding is required for confirmation of the positional relationships between the courses of lymphatic vessels, lymph node distribution, and the left RLN and its tracheal branches. We performed a detailed anatomical examination of these relationships.

METHODS

Macroscopic anatomical observation and histological examination was performed on cadavers. In addition to hematoxylin and eosin staining, immunostaining using antipodoplanin antibody D2-40 (podoplanin) was performed to identify the lymphatic vessels.

RESULTS

The tracheal branches of the left RLN were clearly observed, but no lymphatic vessels crossing the ventral or dorsal side of the branches were identified either macro-anatomically or histologically.

CONCLUSION

No complex lymphatic network structure straddling the plane composed of tracheal branches of the left RLN was found in the left superior mediastinum. This suggests that dissection of the lymph nodes around the left RLN via the pneumomediastinum method using the left cervical approach may allow preservation of the tracheal branches of the left RLN by maintaining dissection accuracy.

Iatrogenic lymphocutaneous fistula secondary to right-sided pheresis catheter placement and its percutaneous treatment: a case report

We present a case of an iatrogenic lymphocutaneous fistula secondary to placement of a tunneled, large bore (14.5 Fr) right-sided internal jugular vein for plasmapheresis to treat antibody-mediated kidney transplant rejection. While iatrogenic lymphatic leaks caused by neck and thoracic surgeries are well described in the literature, lymphatic leak or lymphocutaneous fistula resulting from image-guided placement of a central venous catheter through the right internal jugular vein has yet to be described. We also describe the successful percutaneous treatment of this lymphocutaneous fistula using a combination of n-butyl cyanoacrylate glue and embolization coils.

Life threatening presentation of thoracic duct injury post thyroid surgery; a case report

•

Injury to thoracic duct, and the formation of chyle leak, is a rare complication and carries significant metabolic and immunological consequences.

•

Thoracic duct injury during thyroid surgery is an uncommon event with an incidence rate of 0.5–1.8%.

•

High output chyle leak in a confined space was life threatening.

•

Surgeons must be familiar with thoracic duct anatomy.

Background

Injury to thoracic duct is a rare potential complication of time-honored conventional thyroidectomy. Nevertheless, it can be a cause of significant morbidity, and sometimes life-threatening.

Patient findings

A 78-year-old female patient with a previous surgical history of thyroid lobectomy for nodular disease presented with primary hyperparathyroidism, and a nodule in the remaining thyroid lobe. The patient underwent completion thyroidectomy and parathyroidectomy. Less than 24 h post operatively, the patient developed progressive shortness of breath and neck swelling requiring immediate intubation and re-exploration. A large amount of chyle was drained and an injured thoracic duct was identified and ligated.

Summary

In experienced hands thyroid surgery is safe. Nevertheless, factors such as the type of pathology and its extent, the level of surgery, and re-operative surgery increase the risk of postoperative complications. Immediate surgical exploration is necessary when patients present with neck swelling and respiratory distress. In our case, a high output chyle leak in a confined space was life threatening.

Conclusion

Timely re-exploration following thyroid surgery and thorough knowledge of the anatomy of neck structures is crucial in sparing patients potential morbidity and/or mortality.

Chylothorax and central vein thrombosis, an under-recognized association: a case series

Chylothorax is defined as the presence of chyle in the pleural cavity. Central vein thrombosis is an under‐recognized cause of chylothorax in the adult population and is commonly related to central venous catheterization. Case 1 illustrates a patient with AIDS and disseminated tuberculosis with left chylothorax and central vein thrombosis after a month of antituberculosis therapy. Case 2 was a patient with advanced seminoma who presented with left chylothorax and central vein thrombosis while on chemotherapy. Chylothorax resolved with anticoagulation for both cases. Case 3 was a lymphoma patient with central vein thrombosis who developed chylothorax during chemotherapy. Chylothorax resolved with the continuation of anticoagulation and did not recur despite his progressive underlying lymphoma. There was no central venous catheterization in any of these three cases. These cases illustrate the unique association of central vein thrombosis and chylothorax and the importance of anticoagulation in its management.

Localization of thoracic duct using heavily T2W MRI for intractable post-esophagectomy chylothorax-a case report

Post-esophagectomy chylothorax is a rare yet serious complication. Herein we report the case of a patient with intractable post-esophagectomy chylothorax despite medical treatment with total parenteral nutrition and octreotide, as well as prophylactic and repeated thoracic duct mass ligation. The patient was eventually treated with localization of thoracic duct using T2-weighted magnetic resonance imaging (T2W MRI), followed by video-assisted thoracoscopic thoracic duct ligation.

Investigational lymphatic imaging at the bedside in a pediatric postoperative chylothorax patient

Chylothorax is a rare but serious complication in children who undergo heart surgery. Its pathogenesis is poorly understood, and invasive surgical treatments are considered only after conservative management fails. Current diagnostic imaging techniques, which could aid decision making for earlier surgical intervention, are difficult to apply. Herein, we deployed near-infrared fluorescence (NIRF) lymphatic imaging to allow the visualization of abnormal lymphatic drainage in an infant with postoperative chylothorax to guide the choice of surgical management. A 5-week-old male infant, who developed chylothoraces after undergoing Norwood surgery for hypoplastic left heart syndrome, was intradermally administered trace doses of indocyanine green in both feet and the left hand. NIRF imaging was then performed at the bedside to visualize lymphatic drainage patterns. Imaging results indicated impeded lymphatic drainage from the feet toward the trunk with no fluorescence in the chest indicating no leakage of peripheral lymph at the thoracic duct. Instead, lymph drainage occurred from the axilla directly into the pleural cavity. As a result of imaging, left pleurodesis was performed to stop the pleural effusion with the result of temporary decrease of left chest tube drainage. Although additional studies are required to understand normal and abnormal lymphatic drainage patterns in infants, we showed the potential of using NIRF lymphatic imaging at the bedside to visualize the lymphatic drainage pathway to guide therapy. Timely management of chylothorax may be improved by using NIRF imaging to understand lymphatic drainage pathways.

Outcomes of fetal intervention for primary hydrothorax

OBJECTIVE

Primary hydrothorax is a rare congenital anomaly with outcomes ranging from spontaneous resolution to fetal demise. We reviewed our experience with fetuses diagnosed with primary hydrothorax to evaluate prenatal management strategies.

METHODS

We reviewed the records of patients evaluated for fetal pleural effusions at our Fetal Treatment Center between 1996 and 2013. To define fetuses with primary hydrothorax, we excluded those with structural or genetic anomalies, diffuse lymphangiectasia, immune hydrops, and monochorionic diamniotic twin gestations.

RESULTS

We identified 31 fetuses with primary hydrothorax, of whom 24 had hydrops. Hydropic fetuses were more likely to present with bilateral effusions. Of all fetuses with primary hydrothorax, 21 had fetal interventions. Survival without hydrops was 7/7 (100%), whereas survival with hydrops depended on whether or not the patient had fetal intervention: 12/19 (63%) with intervention and 1/5 (20%) without intervention. Premature delivery was common (44%) among those who had fetal intervention.

CONCLUSIONS

Fetal intervention for primary hydrothorax may lead to resolution of hydrops, but preterm birth and neonatal demise still occur. Understanding the pathophysiology of hydrops may provide insights into further prenatal management strategies, including targeted therapies to prevent preterm labor.

Evolution of chylous fistula management after neck dissection

PURPOSE OF REVIEW

The present review is focused on the management of lymphatic, chylous, and thoracic duct lesions following head and neck surgery, with particular attention to these complications after neck dissection. Postoperative scenarios may include chylous fistula, chylothorax, chylomediastinum, chylopericardium, lymphocele, persistent lymphorrhea, and secondary lymphedema.

RECENT FINDINGS

There is a paucity of literature on the treatment of lymphatic, chylous, and thoracic duct injuries following head and neck surgery; however, this review suggests that the most appropriate treatment should include both conservative and surgical approaches. Nonsurgical options consist of low-fat diet with medium-chain triglycerides, total parenteral nutrition, careful monitoring of fluid and electrolytes, drainage of the leakage, somatostatin analogs such as octreotide, and negative-pressure wound therapy. On the other hand, surgical management includes therapeutic percutaneous lymphography-guided thoracic duct cannulation and embolization, thoracic duct ligation, excision and imbrication of leaking lymphatics, chylous fistula surgical/microsurgical repair, fistula closure by locoregional flaps, video-assisted thoracoscopic surgery, thoracotomy, pleurodesis and decortication, pericardial 'window', and pleura-venous/pleura-peritoneal shunts. In addition, single or, preferably, multiple lymphovenous anastomoses may be taken into account.

SUMMARY

The various possible clinical presentations of such challenging lymphatic, chylous, and thoracic duct injuries require an appropriate multidisciplinary approach by experienced teams. Primary prevention of these complications can be achieved through adequate surgical planning to minimize lesions, including structured and thorough patient assessment, and centralization of resources and teams.

[Anatomic variations in the surgical anatomy of the thoracic esophagus and its surrounding structures]

BACKGROUND

Esophagectomy is a challenging procedure due to: a) it is a complex operation; b) it is linked to very high morbidity and mortality rates; c) surgical anatomy of the esophagus is very peculiar. The anatomic variations that can be unexpectedly found during an operation may cause complications and influence the outcome.

AIM

To review the anatomic basis for esophagectomy focusing on anatomic variations found in the mediastinal structures based on literature review and cadaver dissection.

METHODS

Literature related to the surgical anatomy of the esophagus and mediastinal structures was reviewed. Also, a total of 20 fresh (non-embalmed, non-preserved, time of death under 12 h) human cadavers were dissected. There were 16 male and mean age was 53 ± 23 years.

RESULTS

Anatomic variations for aorta, azygos system, pleura, vagus nerve, lymph nodes and thoracic duct were documented.

CONCLUSIONS

The organs and structures of the mediastinum may frequently present anatomic variations. Some of these may be clinically significant during an esophagectomy. Because only a part of them may be identified before the operation with the current imaging tools, surgeons must be aware of these anatomic variations.

Defying gravity: subdiaphragmatic causes of pleural effusions

Intra-abdominal fluid may migrate readily into the pleural space through naturally occurring holes in the diaphragm or intradiaphragmatic lymphatics. Although any type of fluid in the abdomen may migrate, additional pathologic mechanisms are involved in the development of chylous ascites/chylothorax, yellow nail syndrome, urinothorax, pancreaticopleural fistulas, or other connections. In the differential diagnosis of the large list of potential pleural fluid causes, intra-abdominal sources should be entertained by the practicing physician in the right clinical context.