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

Chylothorax: a rare postoperative complication in paediatric cardiac surgery patients - a 15-year retrospective study from a tertiary care centre in a developing country

Chylothorax, a postoperative complication of CHD surgery, involves chyle accumulation in the pleural cavity, posing challenges in diagnosis and management. This retrospective study investigates the prevalence, aetiology, management, and outcomes of postoperative chylothorax in paediatric patients undergoing cardiac corrective surgery at a tertiary care centre over 15 years. Medical records of paediatric patients who underwent cardiothoracic surgery at the Children's Heart Center at the American University of Beirut Medical Center between 2007 and 2022 were retrospectively reviewed. Data collection included demographic characteristics, blood parameters, chylous fluid characteristics, diagnostic criteria, treatment modalities, and hospitalisation details. Ethical approval was obtained, and descriptive statistics were employed using SAS 9.4. Among 2,997 children who underwent cardiothoracic surgery, nineteen cases of postoperative chylothorax were identified. The majority were females (63.2%) with a median age of 9 months. Glenn, Fontan, and Blalock-Taussig shunt-related surgeries were the most common operations associated with chylothorax. Single ventricle physiology was the predominant CHD observed (58%). Diagnosis relied primarily on clinical presentation, imaging studies, and triglyceride levels in pleural fluid. Treatment options included conservative dietary modifications, medical therapy such as octreotide, and surgical intervention if necessary. No mortalities were reported, and patients were adequately followed up. This study sheds light on postoperative chylothorax in paediatric cardiac patients, offering insights into its epidemiology, aetiology, clinical features, and treatment outcomes. While conservative and medical approaches effectively managed chylothorax in this group, larger studies are needed to develop standardised diagnostic and treatment protocols, improving outcomes in paediatric patients with postoperative chylothorax.

Pleurodesis using OK-432 for persistent pleural effusion after cardiac surgery in the neonatal period or early infancy

OBJECTIVE

To evaluate the efficacy of pleurodesis using OK-432 after cardiac surgery in the neonatal period or early infancy.

METHODS

We retrospectively reviewed the data of 11 consecutive patients who underwent cardiac surgery in the neonatal period or early infancy and pleurodesis using OK-432 for persistent postoperative pleural effusion in two institutions.

RESULTS

The median age at surgery was 8 days (interquartile range [IR], 2-18) with a body weight of 2.84 kg (IR, 2.30-3.07). The maximum amount of pleural drainage before pleurodesis was 94.7 (IR, 60.2-107.7) ml/kg/day. Pleurodesis was initiated at postoperative day 20 (IR, 17-22) and performed in bilateral pleural spaces in seven patients and unilateral in four. The median numbers of injection were 4 (IR, 3-6) times per patient and 3 (IR, 2-3) times per pleural space. In 10 patients, pleural effusion was decreased effectively, and drainage tubes were removed without reaccumulation within 15 (IR, 12-28) days after initial pleurodesis. However, in one patient, with severe lymphedema, pleural effusion was uncontrollable, resulting in death due to sepsis. Adverse events were observed in nine patients; temporal deterioration of lung compliance and arterial blood gas occurred in two, insufficient drainage requiring new chest tube(s) in five, temporal atrial tachyarrhythmia in one, and lymphedema in four.

CONCLUSIONS

Pleurodesis using OK-432 is effective and reliable for persistent postoperative pleural effusion in neonates and early infants. Most of the complications, which derived from inflammatory reactions, were temporary and controllable. However, severe lymphedema is difficult to control.

Understanding Lymphatic Anatomy and Abnormalities at Imaging

Lymphatic abnormalities encompass a wide range of disorders spanning solitary common cystic lymphatic malformations (LMs) to entities involving multiple organ systems such as lymphangioleiomyomatosis. Many of these disorders are rare, yet some, such as secondary lymphedema from the treatment of malignancy (radiation therapy and/or lymph node dissection), affect millions of patients worldwide. Owing to complex and variable anatomy, the lymphatics are not as well understood as other organ systems. Further complicating this is the variability in the description of lymphatic disease processes and their nomenclature in the medical literature. In recent years, medical imaging has begun to facilitate a deeper understanding of the physiology and pathologic processes that involve the lymphatic system. Radiology is playing an important and growing role in the diagnosis and treatment of many lymphatic conditions. The authors describe both normal and common variant lymphatic anatomy. Various imaging modalities including nuclear medicine lymphoscintigraphy, conventional lymphangiography, and MR lymphangiography used in the diagnosis and treatment of lymphatic disorders are highlighted. The authors discuss imaging many of the common and uncommon lymphatic disorders, including primary LMs described by the International Society for the Study of Vascular Anomalies 2018 classification system (microcystic, mixed, and macrocystic LMs; primary lymphedema). Secondary central lymphatic disorders are also detailed, including secondary lymphedema and chylous leaks, as well as lymphatic disorders not otherwise easily classified. The authors aim to provide the reader with an overview of the anatomy, pathology, imaging findings, and treatment of a wide variety of lymphatic conditions. ^©RSNA, 2022.

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.

Nutrition Considerations in the Pediatric Cardiac Intensive Care Unit Patient

Adequate caloric intake plays a vital role in the course of illness and the recovery of critically ill patients. Nutritional status and nutrient delivery during critical illness have been linked to clinical outcomes such as mortality, incidence of infection, and length of stay. However, feeding practices with critically ill pediatric patients after cardiac surgery are variable. The Pediatric Cardiac Intensive Care Society sought to provide an expert review on provision of nutrition to pediatric cardiac intensive care patients, including caloric requirements, practical considerations for providing nutrition, safety of enteral nutrition in controversial populations, feeding considerations with chylothorax, and the benefits of feeding beyond nutrition. This article addresses these areas of concern and controversy.