ACR Appropriateness Criteria ® Chylothorax Treatment Planning

Abstract

Chylothorax is an uncommon but serious medical condition, which arises when intestinal lymphatic fluid leaks into the pleural space. Treatment strategies depend on the daily output and underlying etiology, which may be due to direct injury to lymphatic vessels or a nontraumatic disorder. Chest radiographs confirm the presence of pleural fluid and lateralize the process. In the setting of direct injury, lymphangiography can often be both diagnostic and facilitate a minimally invasive attempt at therapy. CT and MRI in this setting may be appropriate for cases when lymphangiography is not diagnostic. When the etiology is nontraumatic or unknown, CT or MRI can narrow the differential diagnosis, and lymphangiography is useful if a minimally invasive approach to treatment is desired. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

An uncommon therapeutic option for a challenging cause of pleural effusion

“…The causes of chylothorax (table 2) are traumatic or nontraumatic interruption of the flow of chyle through the thoracic duct [2, 4, 5]. The iatrogenic traumatic causes occur after thoracic surgery, most often surgery of the oesophagus, or after radiotherapy.…”

“…The first step of treatment for a chylothorax is medical [2, 4–6]: chest tube drainage and a low-fat diet (<10 g·day −1 ), rich in proteins, without long-chain triglycerides but rich in medium-chain triglycerides [7, 8]. This diet may be replaced by parenteral nutrition alone.…”

“…If there is high output of chyle (>1000 mL·day −1 ), a persistence of output >500 mL·day −1 over 2 weeks or an underlying neoplastic aetiology, invasive treatment should be considered: either surgical treatment or interventional radiology [2, 4–6]. In this case report, there was a 2-month delay before invasive treatment, exposing the patient to malnutrition (reflected by his low albumin level on arrival) and social problems because he was not able to work while hospitalised.…”

MRI of the Central Lymphatic System

“…19 The recently published ACR guidelines from 2017 regarding chylothorax treatment assign contrast-enhanced and noncontrast MRL an appropriateness score of 7 (usually appropriate) for chylothorax of nontraumatic or unknown etiology, and a score of 6 (may be appropriate) for chylothorax of traumatic etiology. 20 …”

Outpatient facility-based order variation in combined imaging

“…[5] Likewise, the ACR has released Appropriateness Criteria® stating that combined thoracic imaging may be appropriate for chylothorax treatment planning, as well as for the evaluation of chronic chest pain among patients with high probability of coronary artery disease. [6, 7] Similarly, while simultaneous CTs of the brain and sinus are often not needed due to the highly overlapping anatomy, such exams may be appropriate in situations involving comorbidities such as cancer, trauma, or orbital cellulitis. [8]…”