Treatment Of Post-Operative Chylothorax: The Role Of Intranodal Lymphangiography And Thoracic Duct Disruption.

Thoracic duct embolization has been increasingly adopted as a first-line therapy of chylothorax and this procedure includes lipiodol lymphangiography, thoracic duct access and embolization. Lymphangiography itself has a therapeutic role, with volume-dependent success rates of 37%-97% and even a reported 100% success rate in outputs of < 500 mL/day. We present a clinical case of a 48-years-old man diagnosed with esophageal squamous cell carcinoma, who underwent esophagectomy and presented with post-operative high-output (> 1L/day) chylothorax; thoracic duct embolization was proposed. Even though thoracic duct access and embolization were not achieved due to technical and anatomical factors, lipiodol lymphangiography and possibly thoracic duct maceration (after several punctures/attempts) contributed to the clinical success of the procedure, and this chylothorax with output values superior to those reported in the literature resolved within three days. As such, the therapeutic role of intranodal lymphangiography and thoracic duct disruption should be taken into account.

Thoracic Duct Lymphangiography via the Testicular Parenchyma in a Rabbit Model.

This study aimed to establish an animal model for thoracic duct lymphangiography using ethiodized oil. Thoracic duct lymphangiography was performed via the testes in 21 Japanese white rabbits. The testicular parenchyma was punctured by palpation using a 30-gauge, 0.5-inch needle. Ethiodized oil was injected at a rate of 11.41 mL/h until the testicular efferent lymphatic vessels were delineated and then at a rate of 2.85 mL/h until the entire thoracic duct was delineated. Thoracic duct delineation was 100% successful and showed good depiction based on visual scores. The mean ethiodized oil dose administered was 4.59 mL ± 1.41, and the mean time to visualize the entire thoracic duct was 43.7 minutes ± 14.1. The presented model may serve as a method for future preclinical investigation of the thoracic duct anatomy and for thoracic duct interventions.

Estimation of the Lymph Flow Through Thoracic Duct in Human Subjects Using the Urine Osmolarity: Applicable for Evaluating the Effectiveness of Manual Lymph Drainage.

Currently, there are many methods to evaluate the effectiveness of manual lymph drainage in the treatment of lymphedema, that is, limb volume measurement, bio-electrical impedance measurement, computer tomography, and ultrasound imaging. However, it is difficult for these methods to accurately address the lymph flow generated by manual lymph drainage. Therefore, we aimed at developing a concise and accurate method to measure the lymph flow through the thoracic duct in human subjects, which is applicable for evaluating the effectiveness of manual lymph drainage. In the present mini-review, we demonstrate the developed method in detail and its scientific evidence for the effectiveness obtained with animal and human clinical experiments. In rat in vivo experiments, intragastric administration of distilled water significantly increased mesenteric flow, which was transported via the cisterna chyli and then the thoracic duct. The manual massage on the cisterna chyli in the anesthetized rabbit significantly accelerated the lymph flow through the thoracic duct, resulting in marked hemodilution. Abdominal respiration in the supine position in human subjects produced similar hemodilution, with a marked decrease in the concentration of vasopressin in the blood. On this basis, we developed a new method to accurately measure the lymph flow through the thoracic duct by using changes in the concentration of vasopressin in the blood. In addition, with changes in urine osmolarity depending on the concentration of vasopressin in the blood, we developed a more concise and noninvasive method for evaluating the lymph flow through the thoracic duct in human subjects. These methods may be applicable for evaluating the effectiveness for the manual lymph drainage in the patients with lymphedema.

A Canine Model for Lymphangiography and Thoracic Duct Access.

OBJECTIVE: To evaluate the technical feasibility of intranodal lymphangiography and thoracic duct (TD) access in a canine model. MATERIALS AND METHODS: Five male mongrel dogs were studied. The dog was placed in the supine position, and the most prominent lymph node in the groin was accessed using a 26-gauge spinal needle under ultrasonography (US) guidance. If the cisterna chyli (CC) was not opacified by bilateral lymphangiography, the medial iliac lymph nodes were directly punctured and Lipiodol was injected. After opacification, the CC was directly punctured with a 22-gauge needle. A 0.018-in microguidewire was advanced through the CC and TD. A 4-Fr introducer and dilator were then advanced over the wire. The microguidewire was changed to a 0.035-in guidewire, and this was advanced into the left subclavian vein through the terminal valve of the TD. Retrograde TD access was performed using a snare kit. RESULTS: US-guided lymphangiography (including intranodal injection of Lipiodol [Guerbet]) was successful in all five dogs. However, in three of the five dogs (60%), the medial iliac lymph nodes were not fully opacified due to overt Lipiodol extravasation at the initial injection site. In these dogs, contralateral superficial inguinal intranodal injection was performed. However, two of these three dogs subsequently underwent direct medial iliac lymph node puncture under fluoroscopy guidance to deliver additional Lipiodol into the lymphatic system. Transabdominal CC puncture and cannulation with a 4-Fr introducer was successful in all five dogs. Transvenous retrograde catheterization of the TD (performed using a snare kit) was also successful in all five dogs. CONCLUSION: A canine model may be appropriate for intranodal lymphangiography and TD access. Most lymphatic intervention techniques can be performed in a canine using the same instruments that are employed in a clinical setting.

Yellow nail syndrome resulting from cardiac mitral valve replacement.

BACKGROUND: Yellow nail syndrome is a rare disease with unknown etiology, Attributed to functional anomalies or disturbance in lymphatic drainage. This condition is characterized by triad of nail discoloration, respiratory or intrathoracic manifestations and lymphedema. CASE PRESENTATION: Twenty days after mitral valve replacement for severe rheumatic mitral valve stenosis, 39 years old woman presented with face tenderness and hearing problems besides stuffy and clogged nose and underwent routin rhinosinusitis therapy. She came back to ears, nose and throat service with persistent rhinosinusitis as well as relapsing preoperative couphs and dyspnea besides lower extremities edema and toenails discoloration. After some modulations of treatment, she was introduced to pulmonary clinic on post -operative day = 30. Chest x ray showed a lot of left pleural effusion then she was returned to our service (cardiac surgery) on post- operative day = 33. The pigtail catheter was secured and we attained a significant amount of milky fluid which conformed with chylothorax. Finally Yellow nail syndrome was diagnosed with her on post-operative day = 35. Early conservative therapy such as bed rest, legs massage, low fat diet with medium chain triglycerides, diuretics, bronchodilator inhaler was not be able to satisfy us (chylous out put > 330 cc/d). Therefore the catheter replacement with chest tube was carried out followed by pleurodesis using Talc and doxycycline besides transition of oral intake to total parentral nutrition and vitamine E supplement, on post - operative day = 41. After that chylous leakage gradually subsided and patient was discharged to home on post- operative day = 47. At 4 weeks follow ups, chest x ray was clear without effusion and nails discoloration and legs lymphedema resolved. CONCLUSION: We reported the third post cardiac surgery Yellow nail syndrome which is an unclear entity with a set of associated signs and symptoms. Two prior reports involved with coronary artery bypass graft whereas we performed mitral valve replacement. In angiogram thoracic duct was not identified so that it seems post cardiac surgery Yellow nail the syndrome has iatrogenic origin due to the thoracic duct or its tributaries injury and requires meticulous assessment and management.

[Intranodal lymphangiography in pediatric chylothorax, a diagnostic and therapeutic tool]. / Linfangiografía intranodal en quilotórax pediátrico, una herramienta diagnóstica y terapéutica.

INTRODUCTION: High morbidity has been described in secondary chylothorax. Thoracic duct embolization (TDE) after intranodal lymphangiography (IL) is one of the treatments in adults but there is poor experience in children. We aim to describe our experience with this technique for refractory pediatric chylothorax. METHODS: A retrospective study of patients with refractory chylothorax treated with thoracic duct embolization at our Institution in the last 4 years was performed. Lymphatic vessels visualization was obtained by intranodal lymphangiography with ethiodized oil. Demographic and clinical data as well as imaging findings were collected. RESULTS: A total of 4 patients were treated during the study period with a median of age and weight of 2.5 months (1-16) and 4.25 kg (2.8-10) respectively. Chylothorax was secondary to cardiothoracic surgery in 3 patients and to venous thrombosis in the other one. Medical treatment was provided during a median of 47 days (13-56) without benefit in thoracic output [median: 46 ml/kg/day (19-64)]. After IL, thoracic duct catheterization was achieved in one patient however embolization was not possible. Chylothorax stopped in the 3 post-surgical patients regardless of how much lymphatic visualization was achieved in IL. In the venous thrombosis patient surgical treatment was performed 6 days after the study. CONCLUSION: IL can be a diagnostic and therapeutic tool in children. Ethiodized oil seems to seal lymphatic leak in postsurgical chylothorax. IL could be an option for chylothorax in patients too sick for surgical treatment or in whom thoracic duct embolization is not feasible.

INTRODUCCION: El quilotórax secundario es una entidad rara con una alta morbilidad. La embolización del conducto torácico (CT) mediante linfangiografía intranodal (LI) con aceite etiodizado (AE) forma parte del arsenal terapéutico del quilotórax en el adulto. Presentamos nuestra experiencia con esta técnica en pacientes pediátricos con quilotórax refractario al tratamiento médico. METODOS: Estudio retrospectivo de los pacientes tratados en nuestro centro por quilotórax refractario con LI en los últimos 4 años. Se recogieron los datos epidemiológicos, clínicos, terapéuticos y linfangiográficos. RESULTADOS: Se identificaron 4 pacientes, con unas medianas de edad y peso de 2,5 meses (1-16) y 4,25 kg (2,8-10) respectivamente. En 3 de los pacientes el quilotórax fue secundario a cirugía cardiaca y en el restante a trombosis extensa de vena cava superior. La mediana de débito fue de 46 ml/kg/día (19-64) y la de tiempo de tratamiento médico de 47 días (13-56). En todos ellos se realizó LI, opacificándose el CT solo en un paciente, sin lograrse la embolización. A pesar de ello, tras la LI, el quilotórax cesó en el grupo postquirúrgico independientemente del nivel de opacificación del árbol linfático. En el paciente secundario a trombosis, se realizó ligadura quirúrgica del CT 6 días después del estudio. CONCLUSIONES: La LI es una técnica diagnóstica e incluso terapéutica en casos de quilotórax refractario, que comienza a ser necesaria y realizable en centros con experiencia. El AE parece sellar la fuga linfática por un mecanismo embolizante en casos postquirúrgicos, eliminando la necesidad del cierre quirúrgico.

Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery.

PURPOSE: This study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route. METHODS: Data were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct and leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5-1:20). RESULTS: Clinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped. CONCLUSIONS: TDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.

Nontraumatic Chylothorax: Diagnostic Algorithm and Treatment Options.

Nontraumatic chylothorax is a relatively rare condition in which the intestinal lymph (chyle) leaks into the pleural cavity. Nontraumatic chylothorax is more difficult to treat than the more common traumatic chylothorax because the site of chylous leak may occur in less predictable locations. In the past, patients with nontraumatic chylothoraces were offered traditional fluoroscopically guided lymphangiography and thoracic duct embolization similar to traumatic chylothorax. However, the observation that thoracic duct embolization outcomes for nontraumatic chylothorax differed based on the imaging findings during lymphangiography has led to the development of a treatment algorithm, which incorporates noninvasive diagnostic studies, such as magnetic resonance lymphangiography. The development of this systematic approach allows better delineation of the source of the chylous leak and selection of the appropriate method of embolization. In this article, we will review the etiologies of nontraumatic chylothorax, the diagnostic work-up for managing this condition, and the treatment algorithm to care for these patients.

Therapeutic role of ultrasound-guided intranodal lymphangiography in refractory cervical chylous leakage after neck dissection: Report of a case and review of the literature.

BACKGROUND: Chylous leakage is a well-recognized but rare complication of head and neck surgery, affecting approximately 1% to 2.5% of head and neck dissections. It is a potentially life-threatening condition characterized by electrolyte imbalance, immunosuppression, delayed wound healing, risk of infection, and generalized sepsis. Management can be problematic and prolonged. METHODS: We present a case of refractory cervical chylous leakage after neck dissection treated with ultrasound-guided intranodal lymphangiography. RESULTS: Ultrasound-guided intranodal lymphangiography alone resulted in rapid and complete resolution of chylous leakage with minimal morbidity. CONCLUSION: Based on our clinical experience and after a thorough literature review, we propose that ultrasound-guided intranodal lymphangiography with contrast agent could be considered a viable therapeutic option for persistent chylous leakages in selected patients.

[Transnodal ultrasound-guided lymphangiography for thoracic duct embolization in chylothorax]. / Ultraschall-gesteuerte transnodale Lymphangiographie mit perkutanem Verschluss des Ductus thoracicus beim Chylothorax.

INTRODUCTION: To evaluate the feasibility of ultrasound-guided transnodal lymphangiography as an modified technique for visualization of the abdomino-thoracic lymphatic system for thoracic duct embolization in patients with chylothorax after thoracic surgery. METHODS: 10 patients (six men and four women, mean age 53 y [range, 22-72 y]) with chylothorax after thoracic surgery underwent ultrasound-guided transnodal lymphangiography. An inguinal lymph node was accessed under ultrasound guidance with a 25-gauge spinal needle and lipiodol was injected. Opacification of the lymphatic system was intermittently controlled by fluoroscopy. The thoracic duct was percutaneously accessed and embolization was performed. Following mean times were assessed: for the procedure of inguinal puncture, number of inguinal punctures, time from start of lipiodol injection until inguinal lymphangiogram, volume of injected contrast media, duration of opacification of target lymphatics, number of percutaneous punctions and time for thoracic duct access, time for thoracic duct embolization and complications. Procedure times until initial lymphangiogram were compared with times of a control group (n=10) in patients who had undergone pedal lymphangiography. RESULTS: The procedure of ultrasound guided lymph node puncture was successful in all cases (10 /10). Mean procedure times from inguinal access to initial lymphangiogram were 12.3 ±â€…2 minutes (pedal lymphangiography : 30.4 ±â€…5 minutes). Average of inguinal punctions was 1.3 (1-3). Small extravasation occurred in 4 of 10 patients. In 2 patients a contralateral inguinal punction was necessary because of lymphovenous shunts. In 10 /10 patients the lymphatic systems was opacified about 24.5 ±â€…9 minutes for thoracic duct embolization without required additional injection. Average of thoracic duct punctions were 1.5 (1-3). Procedure times until catheterization of the target lymphatics and until embolization of the thoracic duct were 19.3 ±â€…9 minutes and 14.5 ±â€…2 minutes respectively. CONCLUSION: Ultrasound-guided transnodal lymphangiography is a less technically challenging technique for opacification of the abdomino-thoracal lymphatic system for subsequent thoracic duct embolization.

The effect of photodynamic therapy on cisterna chyli patency in rats.

OBJECTIVE: To radiographically and histologically evaluate the effects of photodynamic therapy on the cisterna chyli in rats. STUDY DESIGN: Experimental study. ANIMALS: Adult male Sprague-Dawley rats (n = 60). METHODS: Cecal lymph nodes were injected with the photodynamic compound verteporfin. A 690 nm, 500 mW diode laser was then directed at the area of the cisterna chyli for either 0, 1.5, or 3 minutes. Cisterna chyli patency was evaluated using lymphography, and histologic changes were evaluated on postoperative Days 1, 3, 5, 7, and 14. RESULTS: Histologically, minimal to marked injury to the cisternal and/or pericisternal tissues was present in all treated rats at all time periods. Radiographically, 8/20 cisternae were occluded in the 1.5-minute treatment group (including 1/4 on Day 1, 2/4 on Day 3, 3/4 on Day 5, 0/4 on Day 7, and 2/4 on Day 14), and 9/20 cisternae were occluded in the 3-minute treatment group (including 0/4 on Day 1, 1/4 on Day 3, 3/4 on Day 5, 3/4 on Day 7, and 2/4 on Day 14). There was minimal to no histologic evidence of tissue injury in control rats. All control cisternae were radiographically open. CONCLUSIONS: Further investigations into the timing of laser application and light dose, or alternative photodynamic agents are required to limit injury to adjacent tissues and to improve the effectiveness of cisternal photoablation.

EUS-guided transesophageal study of the human thoracic duct diameter after instillation of intraduodenal fatty acids (EUS-TEST study).

INTRODUCTION: The accession of the thoracic duct (TD) may be vital for obtaining lymph samples, which may be potentially important for early detection of gastrointestinal cancers. The feasibility and safety of endoscopic ultrasound (EUS)-guided TD puncture were recently demonstrated in a swine model. However, the actual process of lymph aspiration is difficult because of small TD diameter (TDD) as well as sluggish flow. This study was designed to examine the change in TDD following intraduodenal instillation of fatty acids (Intralipid(®); manufactured by Fresenius Kabi [Uppsala, Sweden] for Baxter Healthcare [Deerfield, IL]) in patients undergoing diagnostic EUS. PATIENTS AND METHODS: Ten patients undergoing EUS for routine indications were enrolled in this interventional study at a tertiary-care center in the United States. Baseline TDD was first recorded with EUS in the mediastinum, and the endoscope was advanced into the second part of the duodenum, where 20% Intralipid was instilled. Patients then underwent the complete EUS procedure, and TDD was again measured at 30, 45, 60, 75, and 90 minutes. RESULTS: Mean age of the patients was 63 years (range, 46-83 years). The mean (±2 standard deviation) TDD at baseline was 0.17±0.04 cm (range, 0.11-0.23 cm). Values for TDD at 30 minutes (0.22±0.03 cm; P=.11), 60 minutes (0.35±0.08 cm; P=.0007), and 90 minutes (0.27±0.08 cm; P=.04) were all higher than the baseline measurement. Maximum increase in TDD was observed at 60 minutes, after which TD started returning toward baseline. CONCLUSIONS: TDD increases after intraduodenal instillation of Intralipid in human subjects. This change was statistically most significant at 60 minutes. These observations may be critical for aspiration of lymph samples for early detection of gastrointestinal cancers in humans.

Feasibility of ultrasound-guided intranodal lymphangiogram for thoracic duct embolization.

PURPOSE: To show the feasibility of opacifying the thoracic duct using ultrasound-guided intranodal lymphangiogram (IL) for thoracic duct embolization (TDE). MATERIALS AND METHODS: Six patients (two women and four men, mean age, 59.2 y [range, 43-74 y]) underwent IL and TDE for chylothorax. Under ultrasound guidance, a needle was positioned in a groin lymph node, and lipiodol was injected. The thoracic duct was catheterized, and embolization was performed as indicated. Cumulative times from start of the procedure until initiation of the lymphangiogram, until identification of target lymphatic, until catheterization of the thoracic duct, and until completion of the procedure were collected. Times were compared with times of a control group of six patients (two women and four men, mean age, 66.7 y [range, 49-82 y]) who had undergone TDE using pedal lymphangiography (PL). RESULTS: The procedure of opacification, catheterization, and embolization of the thoracic duct was successful in all cases. Cumulative times (mean ± standard deviation) in the IL and PL groups from start of the procedure until (i) initial lymphangiogram were 20.5 minutes ± 8.6 and 46.5 minutes ± 22.6, (ii) identification of a target lymphatic for catheterization were 60.5 minutes ± 18.2 and 110.5 minutes ± 31.6, (iii) catheterization of the thoracic duct were 79.0 minutes ± 28.9 and 128.2 minutes ± 37.0, and (iv) completion of procedure were 125.8 minutes ± 49.0 and 152.8 minutes ± 36.4. CONCLUSIONS: IL is a feasible technique to visualize the thoracic duct for embolization. Using IL, the thoracic duct may be more quickly visualized and catheterized for TDE than with PL.

[A case of chylothorax in which thoracoscopy under local anesthesia and thoracic duct scintigraphy were useful to locate the leakage site].

BACKGROUND: Detailed investigation of the cause of chylothorax and its treatment should be performed by thoracoscopy under general anesthesia, but if this is difficult due to multiple complications it is possible to perform a detailed investigation by combining thoracoscopy under local anesthesia and thoracic duct scintigraphy. CASE PRESENTATION: A 74-year-old woman presented with exertional dyspnea. Chest X-ray films showed right pleural effusion, and thoracocentesis yielded a milky white pleural effusion, meeting the criteria of chylothorax, after excluding conditions such as malignant lymphoma, amyloidosis and trauma. Since the patient's medical history included pacemaker insertion, dialysis and diabetes, thoracoscopy was performed under local anesthesia rather than general anesthesia, to investigate the cause in detail. The pleural cavity was visualized, but no obvious tumor or other cause was present in the parietal pleura. There was partial adhesion of the lower lobe and chest wall, and the leakage of a milky white pleural effusion from this site was confirmed. We then performed thoracic duct scintigraphy, which revealed an area of enhancement corresponding to the leakage site near the right pulmonary hilum. CONCLUSION: We describe a case in which thoracoscopy under local anesthesia and thoracic duct scintigraphy were useful for determining the leakage site in chylothorax.

Visualization of the thoracic duct with injections of dyes or contrast media into the testicular parenchyma in the rabbit.

The thoracic duct drains lymph from the caudal part of the body to the venous system. The visualization of the thoracic duct is important for diagnosis of chylothorax, which may be caused by the damage of the duct. However, it is not easy to visualize the thoracic duct by injecting dyes and/or contrast media into peripheral lymph nodes and mesenteric lymphatics. In the present study, we examined whether the thoracic duct can be visualized by injecting dyes and contrast media directly into the testicular parenchyma. Under deep pentobarbital anesthesia, 14 male Japanese White rabbits were percutaneously injected with dyes (India ink or methylene blue) or contrast media (iohexol 240, 300, or Lipiodol(TM)) into the testicular parenchyma. Then, we grossly observed the stained thoracic duct or took radiographs and CT images of the duct. In all cases with dyes injections, the thoracic duct was successfully visualized. We observed stained lymphatic vessels from the testis to the duct. In case of contrast media injections, the thoracic duct was visualized with X-ray and CT imaging, when 1.5-2.0 ml per one testis of iohexol 240 at 37 degrees C were injected into the right or both testes. The duct was most clearly visible, 3-5 min after the injections. The results show that the thoracic duct is reliably visualized simply by injecting dyes or contrast media into the testicular parenchyma. Our visualization method may also be applicable to the diagnosis of chylothorax in male animals.

Post-esophagectomy chylous leakage from a duplicated left-sided thoracic duct ligated successfully with left-sided video-assisted thoracoscopic surgery.

Three months after esophagectomy for esophageal cancer, a 58-year-old man presented with fluid trapped in his upper mediastinum due to chylous leakage from a duplicated left-sided thoracic duct that remained after excision of the main thoracic duct. Classical lymphangiography using lipiodol confirmed the presence of duplicated thoracic ducts. Conservative treatments were not effective, and then we performed ligation of the left-sided thoracic duct with left-sided video-assisted thoracoscopic surgery. Anatomic variations of the thoracic duct can result in chylous leakage after thoracic surgery. Even if the patient has anomaly of the thoracic duct, classical lymphangiography is useful for detecting locations of the thoracic duct precisely, allowing for certain ligation of the duct with video-assisted thoracoscopic surgery.

Application of direct cannulation and injection lymphangiography to the study of the canine cardiac and pulmonary efferent mediastinal lymphatics.

Lymphangiograms of canine cardiac and pulmonary efferent mediastinal lymphatics were made by cannulation and injection of Ethiodol. Injections were made singly and serially. The mediastinal lymphatics and lymph nodes, which constitute the pathways of drainage of the heart and lungs, were delineated from the point of cannulation to the right and left inferior cervical region where the right lymphatic duct and thoracic duct are located. Lymphangiography reveals that the lymphatics which drain the heart and lungs may join to form common mediastinal lymphatic channels. Interconnections between mediastinal channels were demonstrated. The lymphatics terminated in the region of both the right lymphatic duct and thoracic duct in every subject. The so-called "cardiac node of Drinker" is usually a group of pretracheal nodes rather than a single node. The pretracheal nodes and those more cephalad receive drainage of lymph from both the heart and lungs. These studies suggest that lymph collected by cannulation of a "cardiac" lymphatic adjacent to the "cardiac node" will contain pulmonary as well as cardiac lymph. Thus the high flows reported by many investigators for "cardiac" lymph probably indicates that pulmonary lymph is mixed with cardiac lymph, and that the experimental data should be interpreted with this in mind.