A Rare Case of Bilateral Chylothorax Resulting From a Subclavian Bypass Surgery: What's the Protocol?

Abstract Chylothorax is a rare but potentially life-threatening complication of thoracic duct injury, occurring in 0.2-1% of cardiothoracic surgeries. It results from the accumulation of chyle in the pleural space, causing symptoms like shortness of breath, chest pain, and coughing. If untreated, it can lead to mortality rates up to 75%. Roughly 83% of chylothorax cases are unilateral with about 17% of cases being bilateral. Diagnosis is confirmed when triglyceride levels in the pleural fluid exceed 110 mg/dL. Due to the lack of standardized treatment protocols, management varies, and conservative approaches are often preferred. We present a case of postoperative bilateral chylothorax following left subclavian bypass surgery. A 66-year-old woman developed shortness of breath after undergoing left subclavian bypass surgery for subclavian steal syndrome. Chest X-ray (CXR) revealed bibasilar atelectasis with bilateral pleural effusions. Chest computerized tomography (CT) scan showed moderate bilateral pleural effusions, clustered pulmonary nodules (2-3 mm), and coronary atherosclerosis. Ultrasound-guided thoracentesis yielded 30cc of milky fluid, with triglyceride levels of 2,260 mg/dL, confirming chylothorax. Lymphoscintigraphy did not identify any active thoracic duct leak. Patient was started on a continuous octreotide drip at 50 mcg/hr for seven days and placed on a low-fat diet to reduce chyle formation. No chest tube was necessary, and her symptoms gradually improved. She did not require total parenteral nutrition (TPN) or strict bowel rest. Serial CXRs showed improvement in lung aeration and trace pleural effusions, eliminating the need for further interventions such as repeat thoracentesis or surgery. She was discharged on a low-fat diet for 4-6 weeks and completed her 7-day course of octreotide (100 mcg three times daily) outpatient. Follow-up CXR at two months confirmed complete resolution of the pleural effusions and chylothorax. This case highlights the challenges in treating chylothorax, given the absence of a standardized protocol. Conservative treatment comprising octreotide and dietary modifications was effective in this patient. Though clinical trials supporting the use of octreotide for chylothorax are limited, its role in reducing lymphatic flow is well-documented. A low-fat diet can also reduce chyle production, helping manage the condition. In this case, early recognition and non-invasive management helped avoid the need for more invasive procedures, such as chest tube placement or surgery. The absence of universally accepted treatment guidelines emphasizes the need for continued research to optimize management strategies. Healthcare professionals should remain vigilant for chylothorax in post-cardiothoracic surgery patients and consider conservative approaches before opting for invasive interventions.