Traumatic Chylothorax after Right Pulmonary Resection. Successful Conservative Management

To the Editor

In relation to the paper published by Terzi [1] about the occurrence of chylothorax after right pulmonary resection, we would like to present a new clinical observation.

A 68-year-old man was admitted to our center for surgical treatment of lung cancer. He had presented with hemoptysis one year before. A right upper lobe lesion was discovered using Thorax CT, but without any intrabronchial lesion visible by bronchoscopy. After mediastinoscopy, the tumor was staged as T₂ N₂ M₀. The patient received neoadjuvant chemotherapy, after which a regression in the ganglion stage was established. A right upper lobectomy associated with a mediastinal lymphadenectomy, including the upper paratracheal region, was performed. The thoracic drainage amounted to about 2,000 ml after 48 hours, and had a clearly milky appearance. Pleural fluid was analyzed; the results were as follows: pH 7.5, glucose 15 mg/dl, proteins 3.3 g/dl, LDH 708 U/l. Cholesterol 59 mg/dl and triglyceride 325 mg/dl.

Conservative treatment for a chylothorax was started immediately, including fasting and total parenteral nutrition via a right subclavian vein catheter. The patient had a satisfactory evolution. The thoracic drainage rate presented a progressive tendency to reduction, until the fourteenth day after diagnosis of this complication, when oral uptake was reinitiated. Drainage tubes were removed without any residual signs of persistence of chylothorax. Chylothorax is a debilitating postoperative complication resulting in an impaired immune system and nutritional state. A chylothorax is formed when the thoracic duct is disrupted and chyle enters the pleural space [2]. The most frequent etiology is tumor, especially lymphoma. The second cause is trauma, usually surgery related to pulmonary, cardiovascular or esophageal procedures. It seems that the incidence of chylothorax is clearly increased by interventions affecting the left subclavian artery, due to the proximity of the confluence of the thoracic duct to the junction of left subclavian and internal jugular veins.

Regarding pulmonary surgery, the risk of developing chylothorax is by far the highest in left upper-lobe procedures. Right pulmonary resections can damage the thoracic duct in its ascending portion in the posterior mediastinum, where it runs between the azygous vein and the descending thoracic aorta [3] [4]. Therefore, radical mediastinal nodal dissection is a risk factor in this complication [1]. See [4] for a description of the anatomic variability of the thoracic duct. Leakage of the lymph can occur when small lymphatic vessels or major tributaries to the thoracic duct have been damaged during surgical procedures on the right side of the thorax, as may have happened in this patient.

 This case also shows the effectiveness of conservative treatment for postoperative chylothorax, particularly the condition has been recognized early - despite high drainage volume in the first postoperative days [1]. Total parenteral nutrition with an adequate composition of medium-chain triglycerides and proteins is of capital importance in avoiding fatal debilitation of the patient due to denourishment and immunodeficiency. More important seems to be intraoperative prevention. Any lymphatic leakage visualized during the operation should be sutured. Routine thoracic duct ligation when an extensive mediastinal lymphadenectomy is planned is another option.

References

• 1 Terzi A, Furlan G, Magnanelli G, Terrini A, Ivic N. Chylothorax after pleuro-pulmonary surgery: a rare but unavoidable complication.  Thorac Cardiovasc Surg. 1994;  42 81-84
• 2 Light R W. Chylothorax and pseudochylothorax. In: Light RW Pleural Diseases. Baltimore; Williams & Wilkins 1990: 284-298
• 3 Vallieres E, Shamji F M, Todd T R. Postneumonectomy chylothorax.  Ann Thorac Surg. 1993;  55 1006-1008
• 4 Malthaner R A, McKneally M F. Anatomy of the thoracic duct and chylothorax. In: Griffith Pearson F Thoracic Surgery. New York; Churchill Livingstone 1995: 1069-1081