Page 30 - 66 thorax49-55_opt

Chylothorax 343
Clinical Presentation Management
The accumulation of chyle in the pleural space from a thoracic duct Nonoperative Management
leak may occur rapidly and produce pressure on other structures in the Thoracentesis may be sufficient to relieve spontaneous chylothorax in
chest, causing acute respiratory distress, dyspnea, and cyanosis with occasional infants; however, chest tube drainage will be necessary for
tachypnea. In the foetus, a pleural effusion may be secondary to gener- the majority of patients. Further, tube drainage allows quantification of
alised hydrops, but a primary lymphatic effusion (idiopathic, secondary the daily chyle leak and promotes pulmonary re-expansion, which may
to subpleural lymphangiectasia, pulmonary sequestration, or associated enhance healing. Chylothorax in newborns usually ceases spontane-
with syndromes such as Down, Turner, and Noonan) can cause medi- ously. In some cases of congenital chylothorax, supportive mechanical
astinal shift and result in hydrops or lead to pulmonary hypoplasia. ventilation may be necessary because of insufficient lung expansion,
Postnatally, the effects of chylothorax and the prolonged loss of chyle persistent foetal circulation, or lung hypoplasia. In cases of severe chylo-
may include malnutrition, hypoproteinaemia, fluid and electrolyte thorax leading to nonimmunologic hydrops foetalis, antenatal manage-
imbalance, metabolic acidosis, and immunodeficiency. ment by intrauterine thoracocentesis or pleuroperitoneal shunting should
In a neonate, symptoms of respiratory embarrassment observed be considered in the absence of significant underlying malformations.
in combination with a pleural effusion strongly suggest chylothorax. For postnatal chylothorax, since identifying the actual site of the
Similar findings are noted in the traumatic postoperative chylothorax. fluid leak is difficult, surgery is often deferred for several weeks.
In the older child, nutritional deficiency is a late manifestation of chyle Most cases of traumatic injury to the thoracic duct can be managed
depletion and occurs when dietary intake is insufficient to replace the successfully by chest tube drainage and replacement of the protein
thoracic duct fluid loss. Fever is not common.
and fat loss. Feeding restricted to medium- or short-chain triglycerides
Diagnosis theoretically results in reduced lymph flow in the thoracic duct and may
Chest roentgenograms typically show massive fluid effusion in the enhance spontaneous healing of a thoracic duct fistula. However, it has
ipsilateral chest with pulmonary compression and mediastinal shift. been shown that any enteral feeding, even with clear fluids, greatly
Bilateral effusions may also occur. Aspiration of the pleural effusion increases thoracic duct flow. Therefore, the optimum management
reveals a clear straw-colored fluid in the fasting patient, which becomes for chyle leak is chest tube drainage, withholding oral feedings, and
milky after feedings. Analysis of the chyle generally reveals a total fat providing total parenteral nutrition (TPN). Cultures of chylous fluid
content of more than 400 mg/dl and a protein content of more than 5 are rarely positive; therefore, providing long-term antibiotics during
g/dl. In a foetus or a fasting neonate, the most useful and simple test the full course of chest tube drainage is not considered necessary.
is to perform a complete cell count and differential on the fluid; when In nonresolving chylothorax, subcutaneous injection of octerotide, a
lymphocytes exceed 80% or 90% of the white cells, a lymphatic effu- somatostatin analogue, at 10 µg/kd/day in 3 divided doses is reported
sion is confirmed. The differential can be compared to that obtained to have excellent results in a number of case reports and should be tried
from the blood count, where lymphocytes rarely represent more than prior to surgical intervention.
70% of white blood cells. Surgical Management
Lymphangiography is useful for defining the site of chyle leakage When chylothorax remains resistant despite prolonged chest tube drain-
or obstruction with penetrating trauma, spontaneous chylothorax, age (2–3 weeks) and TPN, thoracotomy on the ipsilateral side may be
and lymphangiomatous malformation. However, in a nontraumatised necessary. The decision whether to continue with conservative manage-
patient, the site of lymphatic leakage is often difficult to localise. ment or to undertake surgical intervention should be based on the nature
Lymphoscintigraphy may be an alternative to lymphangiography, as it of the underlying disorder, the duration of the fistula, the daily volume
is a faster and less traumatic procedure. of fluid drainage, and the severity of nutritional and/or immunologic
depletion. Ingestion of cream before surgery may facilitate identifica-
tion of the thoracic duct and the fistula. When identified, the draining
lymphatic vessel should be suture ligated above and below the leak with
reinforcement by a pleural or intercostal muscle flap. When a leak can-
not be identified with certainty, or when multiple leaks originate from
the mediastinum, ligation of all the tissues surrounding the aorta at the
level of the hiatus provides the best results. Fibrin glue and argon-beam
coagulation have also been used for ill-defined areas of leakage or
incompletely resected lympangiomas.
Thoracoscopy may occasionally be used to avoid thoracotomy.
The leak, if visualised, can be ligated, cauterised, or sealed with
fibrin glue. If the leak cannot be identified, pleurodesis can be
accomplished with talc or other sclerotic agents under direct vision
through the thoracoscope, but this technique should probably be
avoided in infancy due to the potential consequences on lung and chest
wall growth. If there is concomitant chylopericardium, a pericardial
window can be fashioned.
During any thoracotomy, if chyle leak is noted, the proximal and
distal ends of the leaking duct should be ligated.
Pleuroperitoneal shunts have been reserved for refractory
chylothorax. A Denver double-valve shunt system is the type most
commonly employed; it is totally implanted and allows the patient or
parent to pump the valve to achieve decompression of the pleural fluid
into the abdominal cavity where it is reabsorbed.
Figure 55.1: Right-sided congenital chylothorax in a newborn.