Successful treatment of thoracic duct injury from blunt trauma

Abstract

Chylothorax is a rare condition after blunt trauma. We present a 32-year-olds man with a thoracic duct injury resulting in the right chylothorax after a motor vehicle collision. After the failure of conservative management, the patient underwent lymphangiography and successfully embolized the thoracic duct. This report emphasizes the importance of identifying thoracic duct injury in setting blunt trauma and management of this injury.

Introduction

Chylothorax is an uncommon clinical event, of which most cases are caused by malignancy or thoracic surgical complication and rarely associated with blunt trauma [1]. Once recognized, chylothorax needs proper treatment to avoid severe complications or mortality [2,3]. We report a case of thoracic duct injury from blunt trauma, which was successfully treated by percutaneous embolization.

Case presentation

A 32-year-old male patient was transferred from a peripheral hospital to our hospital due to a thoracic spine injury after a motorcycle collision. At the admission, he was conscious with Glasgow of 15 points, paraplegia. A thoracic computed tomography (CT) showed a translation and dislocation fractures involving T9 and T10 vertebrae (Fig. 1). Bilateral pleural effusion with 2 chest tubes in place. The patient then underwent reduction with pedicle screw surgery. After that, the right chest tube output was 1200 mL/24 h and changed from serosanguinous to milky, 1200 mL/24 h. Left pleural fluid was still serosanguinous, with an amount of 400 mL/24 h. The pleural fluid sample test from the right chest tube demonstrated a triglyceride level of 25.21 mmol/L and cholesterol of 2.67 mmol/L, confirming the presence of chyle.

Fig. 1.

Axial (A), (B) and sagittal (C) CT at the admission showing a translation and dislocation fractures involving T9 and T10 vertebraes and bilateral pleural effusion with 2 chest tubes in place.

Initially, the patient was treated conservatively with octreotide and total parenteral nutrition. With slight improvement after 4 days, a lymphangiography was then performed by a single-beam DSA (Allura Xper FD20, Philips). Under ultrasound guidance, 10 mL lipiodol was slowly injected into bilateral inguinal lymph nodes through a 22-gauge needle. The uptake into the lymphatic chain was then evaluated by intermittent fluoroscopy. At 60 minutes after the injection, an extravasation of lipiodol from the thoracic duct at the level of the ninth thoracic vertebra was found, indicating the disruption of the thoracic duct (Fig. 2). The beam was set oblique position with 25 degrees to the right and 10 degrees caudally. Then, a 22G, 20-cm-long Chiba needle (Chiba, Cook) was approached towards the cisterna chyli under fluoroscopy until touching the vertebra. After that, we turned the beam to other views, and the needle was slowly retracted until the tip was in the cisterna chyli. A haft to 1 mL of contrast was slowly injected into the needle to confirm the needle tip. Afterward, we inserted a stiff 0.018″ guidewire into the thoracic duct through the needle. A 2.7 Fr microcatheter (Progreat, Terumo, Japan) was inserted over the guidewire into the thoracic duct under fluoroscopic guidance. Digital subtraction lymphangiography from the thoracic duct with 3 mL of contrast was then performed to identify the leakage point. Two nonfibered coils of 6/20 cm and 5/15 cm (Interlock-18 coils, Boston Scientific, Natick, MA) were placed just under the disruption of the thoracic duct. Following this, 3 mL of a mixture of N-butyl 2-cyanoacrylate and Lipiodol (ratio 1:2) was injected from the coils to the cisterna chyli before removing the microcatheter (Fig. 2).

Fig. 2.

Intranodal lymphangiography (A) and (B) showing rupture of the thoracic duct at the level of T10 (asterisk). A microcatheter 2.7 Fr (white arrowheads) was accessed into the thoracic duct until the leakage point (C), then the thoracic duct was embolized (D) by 2 metal coils and a mixture of lipiodol and N-butyl 2-cyanoacrylate (NBCA) (ratio 1:2).

After embolization, the patient was treated conservatively with total parenteral nutrition for 5 days before slowly transitioning to an oral diet. The drainage fluid then was remarkably decreased. His diet was advanced without any recurrence of the chylothorax. A thoracic CT was performed on day 2 after embolization and found total occlusion of the thoracic duct (Fig. 3). The chest tubes were removed on day 5 for the left and day 7 for the right, with no recurrent pleural effusion noted. The patient was then transferred to a rehabilitation center.

Fig. 3.

Axial (A), (B) and sagittal (C) CT on Day 2 after embolization showing an accumulation in the thoracic duct (black arrows). The traces of lipiodol are observed in the right pleural space (white arrows) but not in the left pleural space.

Discussion

In general, chylothorax is an unusual clinical event, of which is most often associated with thoracic surgical complication or malignancy but very rare due to nonsurgical trauma. In a report by Valentine & Raffin [4] nonsurgical trauma causes only 6 of 191 cases (3%) of chylothorax during 22 years. Doerr et al. [1] reported 203 patients presenting chylothorax over 21 years, with approximately 50% caused by trauma or surgery but only 1 case of chylothorax due to blunt trauma.

Due to the cover of hemothorax, chylothorax is rarely recognized in a traumatic emergency. When the serosanguinous reduces, chylothorax will appear more clearly with milky color. Once chylothorax is suspected, a pleural fluid sample test is indicated. A plural fluid triglyceride level> 1.24 mmol/L (110 mg/dL) with cholesterol < 5.18 mmol/L (200 mg/dL), the presence of chylomicrons allows making a conclusive diagnosis of chylothorax [1]. After confirming the chylothorax, determining the location of the thoracic duct injury is necessary to plan treatment. Magnetic resonance imaging lymphangiography is a valuable imaging modality to find abnormalities in the lymphatic structure, especially in the thoracic duct [5,6]. Ten milliliters of gadolinium contrast were injected into the bilateral inguinal lymph nodes for 1-2 minutes. 3D spoiled gradient-echo sequence (LAVA) was then performed at the abdominal and thoracic levels to cover from the lumbar lymphatic trunks, cisterna chyli and all the thoracic duct. This technique takes less time than lipiodol lymphangiography because the gadolinium moves in the lymphatic system more quickly than lipiodol. However, the evaluation of the lymphatic injuries may be difficult due to movement artifacts or metal artifact. Lymphangiography is still the gold standard for identifying the thoracic duct injuries [3]. Because lipiodol stays in the lymphatic system long, lymphangiography allows diagnosis and guides the percutaneous intervention [2], [3], [4], [5].

Because the thoracic duct can drain up to 2.4 liters of fluid to the systemic circulation, a thoracic duct leak can result in significant volume losses and even hemodynamic compromise if not appropriately treated [1]. In addition, the chylohydrate contains a large amount of nutrients from the intestine, including (triglycerides, cholesterol, chylomicrons, and proteins) and lymphocytes, so the long-term loss of lymphatic fluid will lead to malnutrition nutrition and immunosuppression [2]. The mortality rate for traumatic chylothorax is 50% if there is no proper treatment [7]. Although there are currently no consensus treatment guidelines for lymphatic duct injury, most authors start with conservative management before offering definitive treatment. The patients will receive a thoracentesis and total parenteral nutrition during 1-2 weeks. The low-fat diets are indicated to minimize the body's production of chyle. Octreotide is usually prescribed to reduce the production of chyle. The success rates of the conservative treatment range from 20% to 80% [4].

Lipiodol lymphangiography will be performed in case of failure with conservative therapy because of both therapeutic and diagnostic benefits [2,3]. Lipiodol is injected into bilateral inguinal lymph nodes under ultrasound guidance or pedal [3,4]. The former is preferred over the latter because of the saving time of the procedure and the volume of lipiodol used. Although lymphangiography is typically performed to plan percutaneous intervention or surgery, it can spontaneously stop chyle leakage in over 50% [8], [9], [10]. Some authors hypothesized that lipiodol might selectively block pathologic lymph ducts and causes a sterile inflammatory reaction that promotes the resolution of lymphatic leakage [3,[8], [9], [10]]. But this phenomenon seems to be efficacy with minor injuries of the lymphatic system. For major injuries, such as total rupture of the thoracic duct in our case, they need to definitive treatments (thoracic duct embolization or thoracic duct ligation) [3].

Thoracic duct embolization is a percutaneous intervention performed immediately after lipiodol lymphangiography. The cisterna chyli is accessed through percutaneous transabdominal catheterization. The microcatheter then is advanced to the chyle leakage position, allowing the thoracic duct to embolize by metallic coils and/or liquid glue (eg, n-butyl-2-cyanoacrylate) [2], [3], [4]. The success rate of this technique is up to 90% if completed embolization. Some potential complications of thoracic duct embolization are lymphedema, protein-losing enteropathy, chylous ascites, and chyluria [11]. Alternatively, surgical thoracic duct ligation is a practical option for high-output or recurrent chylothorax, with a high overall success rate of 90% [9,[12], [13], [14]]. However, more invasive with higher morbidity and mortality (38.8% and 25%, respectively) are drawbacks of this technique [9,[12], [13], [14]].

In conclusion, chylothorax due to blunt trauma is a rare clinical event. Conservative treatment should be tried before definitive treatment. Lymphatic embolization is a safe and effective and feasible for treatment of thoracic duct trauma.

Authors' contributions

LTD, TVS and NTL, DTT, DTH, VVC, THN prepared, drafted, and revised manuscript critically for important intellectual content. Each author gave the final approval of the version to be published and agreed to be accountable for all aspects of the work, ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Ethical approval

Owing to design of case report, institutional review board approval was waived.

Patient consent

Informed consent of patient and his relationship was obtained. Consent for publication was obtained for individual person's data included in the study during the postwithdrawal visit, noted in the patient's paper medical record.