J Thorac Cardiovasc Surg 2003;126:1199-1200
© 2003 The American Association for Thoracic Surgery
Chylous leak after cervical mediastinoscopy
Françoise Le Pimpec Barthes, MDa,
Nicola D'Attellis, MDb,
Jalal Assouad, MDa,
Alain Badia, MDa,
Redha Souilamas, MDa,
Marc Riquet, MD, PhDa,*
a Service de Chirurgie Thoracique, Hôpital Européen Georges Pompidou, Paris, France,
b Service d'Anesthésie Réanimation, Hôpital Européen Georges Pompidou, Paris, France
Received for publication August 29, 2002; accepted for publication October 22, 2002.
* Address for reprints: Marc Riquet, MD, PhD, Service de Chirurgie Thoracique, Hôpital Européen Georges Pompidou, 20-40 rue Leblanc, 75015 Paris, France
marc.riquet{at}hop.egp.ap-hop-paris.fr
Chylous leak after cervical mediastinoscopy is a rare complication.1 To our knowledge, 3 cases have been reported in the literature.2-4 Three consecutive cases observed at our institution drew our attention to its possibly underrated occurrence.
Clinical summary
PATIENT 1. A 16-year-old girl reported having weight loss and asthenia after an episode of erythema nodosum. On physical examination, there was no lymphadenopathy or hepatomegaly. The chest radiograph demonstrated bulky paratracheal lymph nodes. Tuberculosis was suspected but could not be confirmed. Diagnosis was assessed by cervical mediastinoscopy, so as to rule out a lymphoma. During the procedure, active suction drainage of the mediastinal bed was used, yielding 300 mL of a milky fluid on postoperative day 1. A chylous leak was confirmed by the presence of chylomicrons and triglycerides (14.6 mmol/L) in the fluid. Suction was discontinued, and a medium-chain triglyceride (MCT) diet was started. Lymphangiography demonstrated backflow of the contrast medium from the thoracic duct into the paratracheal lymph nodes (Figure 1).
The chylous leak stopped, the mediastinum remained unchanged on successive chest radiographs, and the drain was removed on the fourth postoperative day.
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Figure 1. Lymphangiogram: paratracheal nodes are demonstrated by contrast medium backflowing from the thoracic duct.
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PATIENT 2. A 56-year-old man had a superior vena caval obstruction syndrome. On physical examination, there was no lymphadenopathy or hepatomegaly. Chest tomodensitometry demonstrated a huge right lung tumor and large paratracheal lymph nodes. Fibrobronchoscopy failed to provide a diagnosis. A mediastinoscopy was performed. The mediastinal bed was not drained. The diagnosis of squamous cell carcinoma was confirmed. On postoperative day 3, the mediastinoscopy incision leaked a milky fluid that proved to be chylous (triglycerides, 33.72 mmol/L). An MCT diet was started. The chylous leak ceased 4 days later and never reappeared.
PATIENT 3. A 65-year-old man was admitted to our hospital because of hoarseness related to left recurrent nerve palsy. Chest radiography demonstrated a left upper lobe tumor. Tomodensitometry revealed adenopathies at the level of the aortic window and root of the left main bronchus. The results of fibrobronchoscopy were normal. A mediastinoscopy was performed, confirming the diagnosis of adenocarcinoma. Active suction drainage yielded 250 mL of a milky fluid on postoperative day 1. An MCT diet was started, and the chylous effusion resolved in 7 days after yielding 1500 mL.
Discussion
The chylous leaks observed were moderate and easily controlled with conservative treatment, contrary to those reported in the English literature, which appeared to be more worrisome: in 2 cases the chylous effusion collected within the mediastinum and then ruptured into the pleural cavity, resulting in chylothorax,2,3 and in one case the leak, directly drained from the mediastinum, persisted after failure of thoracic duct ligation before being successfully managed with somatostatin.4 The fact that these 3 cases were observed consecutively in a single institution is probably coincidental but not surprising. In fact, the nodes commonly undergoing biopsy during mediastinoscopy are located along paratracheal lymphatic pathways draining the lymph from the lungs into the venous confluents of the neck. Anatomic studies5 have demonstrated lymphatic vessels joining the thoracic duct directly within the mediastinum (Figure 2)
from nodes located on the right and left lower part6 of these tracheal pathways. Such lymphatic vessels possess valves that prevent reflux of chyle from the thoracic duct. Biopsies of nodes supplied with chylum by lymph vessels with insufficient valves, as illustrated in our first case (Figure 1), might lead to a chylous leak. To our knowledge, such valve insufficiency remains unexplained and is rare. Chylous reflux within the mediastinum remains moderate because of the lymph node tissue mass, which acts as a barrier. Drainage of the mediastinal bed after mediastinoscopy is currently not performed1 and might have disclosed the chylous leak in 2 of our cases. Therefore, in most cases such moderate chylous leaks are probably restrained and plugged within the mediastinum.
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Figure 2. Location of lymph vessels connecting with the thoracic duct within the mediastinum from 4R to 4L.6
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We hypothesize that major chylous backflow leading to significant complications, as reported in the literature, remain rare. On the contrary, we believe that small leaks are probably not so uncommon, remaining undiagnosed because they are restrained within an undrained mediastinum. Such chylous collections are probably unknown, and their frequency is probably underreported.
References
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- Kostiainer S, Menala H, Mattila S, Appelqvist P. Chylothorax. Scand J Thorac Cardiovasc Surg. 1983;17:79–83[Medline]
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- Collard JM, Laterre PF, Boemer F, Reynaert M, Ponlot R. Conservative treatment of post surgical lymphatic leaks with somatostatin-14. Chest. 2000;117:902–905[Abstract/Free Full Text]
- Riquet M, Hidden G, Debesse B. The lymphatic drainage of the lungs into the thoracic duct in the mediastinum. Surg Radiol Anat. 1988;10:165–166[Medline]
- Mountain CF, Dresler CM. Regional lymph node classification for lung cancer staging. Chest. 1997;111:1718–1723[Abstract/Free Full Text]
