428 Progressive shortness of breath in a post CABG patient: Thinking beyond the obvious
B Sain, R Chakraborty, A Varma, K Sarkar- Surgery
Abstract
Background
Post-coronary artery bypass graft (CABG) chylothorax is rare accounting for 0.06-0.09% of the cases.
Case presentation
A 62 year old male patient presented with progressive shortness of breath (mMRC grade 1 to 3) for 6 months. He underwent CABG surgery 7 months prior due to ischemic heart disease. Clinical examination supplemented with radiological imaging revealed evidence of progressive bilateral pleural effusion. Pleural fluid aspiration showed bloody appearance of fluid on right side. Lipid analysis of the aspirate confirmed presence of chylomicrons along with a raised triglyceride level(138mg/dL).
Clinical outcome
A diagnosis of right-sided post CABG chylothorax with left sided transudative fluid was made. Patient was managed with ICD insertion on the right side and started on total parenteral nutrition (TPN). This was followed by permissible carbohydrate intake and TPN for 11 days. Gradual decrease in collection was noticed in the follow-up x-ray with no recurrence of symptoms.
Discussion
Most likely that the anterior mediastinal lymphatic chain got injured during the harvesting of internal mammary artery causing leakage of chyle into the thoracic cavity leading to dyspnoea and chest discomfort.
Conclusion
Lipid measurements may be indicated in all patients with undiagnosed pleural effusion in order to rule out chylothorax. Chylothorax can meet criteria of transudate if associated with congestive cardiac failure, cirrhosis, or nephrotic syndrome. However, the colour of pleural fluid is not always indicative of a chylothorax. While most of the patients can be managed conservatively, surgery is recommended if drainage lasts for more than 1-3 weeks, and daily drainage is 200-500mL.