Diagnosis of EDC is usually established before the age of 2 years when the patient develops symptoms.2 On computed tomography it may present as homogenous lesion with regular margins (Jang et al. 2002). Surgical excision is the mainstay of treatment of EDC. Chylothorax could be one of the post-operative complications associated with EDC.
Causative factors described for development chylothorax can be classified into traumatic and non-traumatic. It could be due to surgical or non-surgical trauma. Whereas, non-traumatic factors include infectious disorder, congenital anomalies, malignancy, miscellaneous disorders or idiopathic. Thoracic duct injury and development of chylothorax after excision of the esophageal duplication cyst (EDC) is rare but known complication (Benedict et al. 2016; Kapoor et al. 2014).
The thoracic duct originates usually at the level of L1 vertebra as a continuation of cisterna chyli. It enters the thorax along the right side of the aorta through the aortic hiatus, in its course at the level of T5 thoracic vertebra it crosses the posterior surface of the aorta to the left, further it continues anterior to scalene muscle in neck, arches to the left and ultimately terminates in the left jugulo-subclavian junction. Thoracic duct injury above the level of T5-6 thoracic vertebra leads to left-sided pleural effusion, while injury below the T5-6 thoracic vertebral level results in right-sided pleural effusion (Merrigan et al. 1997; Bolger et al. 1991; Kettner et al. 1998).
Pleural fluid examination for chylomicrons and triglycerides plays an important role in diagnosing chylothorax. A chylous fluid in pleural effusion typically shows triglycerides levels > l1.1 nmol/l, cholesterol levels less < 200 mg/dl and the presence of chylomicrons (Staats et al. 1980; Seriff et al. 1977; Press et al. 1982). Chylothorax can cause dyselectrolemia, poor nutrition and immunological imbalance in the patient. If leak from thoracic duct is not diagnosed and managed timely it can cause significant morbidity and may even leads to mortality of the patient.
Diagnostic imaging modalities like lymphangiography and lymphoscintigraphy are helpful in confirming chylothorax and detecting the probable site of leak. Lymphangiography, considered as gold standard for chylothorax detection, is an invasive, technically more demanding and has more adverse effects. On the other hand, lymphoscintigraphy is a non-invasive, easy to perform and safe method in evaluating the thoracic duct injury (Pui and Yueh 1998; Sachs et al. 1991). In our case, we used filtered Tc99m sulphur colloid radiopharmaceutical for lymphoscintigraphy. Other agents which have been used for thoracic duct injury detection are serum albumin, Tc99m dextran, aurum-198 (Gold-198), iodine-131 triolein, nanocolloid, oral iodine-123 long-chain fatty acid derivative iodophenyl pentadecanoic acid, or oral iodine-123 heptadecanoic acid (Kettner et al. 1998; Bybel et al. 2001; Sado et al. 2001; Hvid-Jacobsen et al. 1987, 1989; Woolfenden and Struse 1977; Gates et al. 1972; Browse et al. 1997).
In present case, patient developed post-operative complication of chylothorax with continuous leak through ICD. Lymphoscintigraphy with filtered Tc99m sulphur colloid helped in confirming the diagnosis of chyle leak and identifying the possible site of chyle leak as well. In addition, formation of lymphocele was also revealed on SPECT-CT images. In view of above lymphoscintigraphy findings patient’s treatment plan was changed from conservative approach to surgical interventions. Thus, filtered Tc99m Sulphur colloid lymphoscintigraphy proved crucial in the patient management. It not only resolved the clinical dilemma but also gave additional information which could alter the surgical intervention and overall treatment plan.