Postoperative chylomediastinum following subaortic membrane resection with septal myectomy: a rare lymphatic complication of median sternotomy

This is the authors' abstract. We don't add key points for this paper.

A woman in her early 40s with symptomatic subaortic membrane and severe left ventricular outflow tract (LVOT) obstruction underwent subaortic membrane resection with limited septal myectomy via median sternotomy. Her postoperative course was complicated by chylomediastinum, diagnosed by characteristic chest tube drainage and markedly elevated triglyceride levels. Intranodal lymphangiography demonstrated mediastinal lymphatic extravasation with contrast pooling along the superior mediastinal lymphatic chain, without evidence of a discrete thoracic duct injury. Multiple attempts at thoracic duct cannulation and embolisation were unsuccessful. Conservative management was continued with total parenteral nutrition, nil per os status and subcutaneous octreotide, leading to gradual resolution of chylous drainage and complete clinical recovery. At 1-year follow-up, the patient remained asymptomatic with durable relief of LVOT obstruction. This case highlights the effectiveness of conservative therapy for postoperative chylomediastinum when percutaneous interventions fail and underscores the importance of early diagnosis and a stepwise management strategy to avoid unnecessary reoperation.