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

Visualization and prediction of the pleura and thoracic duct: elucidation of changes due to respiration using arterial landmarks and CT images

PURPOSE

The thoracic duct uses the pulsation of accompanying arteries to facilitate lymphatic flow. However, the lymphatic flow mechanism cannot be explained when it does not accompany the arteries. This study aimed to clarify the anatomical position of the thoracic duct and surrounding structures and determine the differences in the thoracic duct length and course during inspiration and expiration.

METHODS

Six cadavers were dissected to observe the positional relationship between the thoracic duct and surrounding structures. Image sequences of anatomical sections from the Visible Korean Human Open Resource were observed and reconstructed to understand their three-dimensional positioning. Inspiratory and expiratory computed tomography scans were used to measure and examine respiratory variations in the distance between the arterial landmarks to predict the thoracic duct length.

RESULTS

The thoracic duct accompanied the arteries for most of its course and was sandwiched between the arteries and pleura, entering the mediastinum. However, there was an area on the cranial side of the aortic arch where the thoracic duct did not accompany the arteries. The distance between the arterial landmarks in this area, which approximate the thoracic duct length, was significantly longer during inspiration (39.3 ± 7.81 mm) than during expiration (31.49 ± 7.01 mm).

CONCLUSION

This study suggests that the pleura entering the mediastinum pushes the thoracic duct toward the arteries to promote lymphatic flow generation by arterial pulsation. Additionally, this study suggests that the lymphatic flow in the thoracic duct is generated by the expansion and contraction of the thoracic duct with respiratory movement.

The right lymphatic duct: basic anatomy and clinical relevance

The anatomical variability of the thoracic duct and the right lymphatic duct predisposes them to inadvertent damage following head and neck surgery thereby leading to chyle leak which is an uncommon complication with potentially significant associated morbidity. Although chyle leak is predominately associated with left-sided neck surgery, it also occurs as a complication of the right-sided neck dissection. Variable figures concerning chyle leakage after right-sided neck dissections were reported, ranging from 0 per cent to higher prevalences such as 14%, 24%, 33% and 60% of total cases of chyle leakages associated with neck surgery. The right-sided complications may implicate the right lymphatic duct and right-sided terminations of the thoracic duct into the venous system which occur in about 1-6% of humans. Other clinically relevant conditions involving the right-sided major lymphatic vessels include chyle leaks following right anterior cervical spine surgery, cysts of the right lymphatic duct and dilatation of the right lymphatic duct in the setting of recurrent cervical swelling. This article presents a review of the literature concerning the basic anatomy and the clinical relevance of the right lymphatic duct and the right-sided terminations of the thoracic duct into the venous circulation.

A Rare Case of Right-Sided Chylothorax Following Thoracoscopic Sympathectomy Due to an Anomalous Thoracic Duct

Chylothorax, despite being a common complication after thoracic surgery, is rare after thoracic sympathectomy, especially on the right side of the thorax. We present a case of a patient who developed a right chylothorax after a thoracoscopic sympathectomy due to the presence of an anomalous thoracic duct located on the right side of the patient's chest. A 37-year-old woman underwent a bilateral video-assisted thoracic sympathectomy for the treatment of primary focal axillary hyperhidrosis. During the postoperative period, there was an excessive discharge of a white, milky fluid through the chest drain, with an average daily output of 350-500 mL/day. Chylothorax was confirmed after laboratory analysis, which revealed a triglyceride level of 146 mg/dL. Due to the worsening appearance of the pleural fluid and the increased drainage volume, reaching 1,000 mL, the patient underwent exploratory videothoracoscopy. During the procedure, a lymphatic fistula was visualized in the region of the sympathetic chain, allowing the identification of an anomalous thoracic duct on the right side of the patient's thorax. The anomalous thoracic duct was dissected, with inferior and superior clipping of the duct. The patient remained stable and was discharged three days after the procedure. This case report describes an especially rare presentation, being one of the few cases of right chylothorax after thoracoscopic sympathectomy described in the literature to date. This study points out that, despite thoracic sympathectomy being considered a safe surgical procedure, unusual complications, such as chylothorax, and anatomical variations of the thoracic duct must be considered.

The Anatomy of the Thoracic Duct and Cisterna Chyli: A Meta-Analysis with Surgical Implications

Background: The thoracic duct (TD) and the cisterna chyli (CC) exhibit a high degree of variability in their topographical and morphometric properties. Materials and Methods: PubMed, Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar were searched to identify all studies that included information regarding the morphometric and topographical characteristics of the TD and CC. Results: The most frequent location of the TD termination was the left venous angle, with a pooled prevalence of 45.29% (95% CI: 25.51-65.81%). Moreover, the TD terminated most commonly as a single vessel (pooled prevalence = 78.41%; 95% CI: 70.91-85.09%). However, it divides into two or more terminating branches in approximately a quarter of the cases. The pooled prevalence of the CC was found to be 55.49% (95% CI: 26.79-82.53%). Conclusions: Our meta-analysis reveals significant variability in the anatomy of the TD and CC, particularly regarding TD termination patterns. Despite the predominance of single-vessel terminations, almost a quarter of cases exhibit branching, highlighting the complexity of the anatomy of the TD. These findings demonstrate the importance of detailed anatomical knowledge for surgeons to minimize the risk of accidental injury during head and neck, as well as thoracic surgeries. Our study provides essential insights that can enhance surgical safety and efficacy, ultimately improving patient outcomes.

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.