Abstract
BACKGROUND: Minimally invasive surgery (MIS) has become a mainstay for lung cancer treatment because of comparable outcomes to open thoracotomy; however, chylothorax remains a notable complication, which can lead to protein and electrolyte depletion, malnutrition, and increased morbidity. This study aimed to (1) determine the incidence of chylothorax after MIS for lung cancer; (2) identify pertinent risk factors; (3) evaluate the effectiveness and limitations of a predominantly conservative treatment algorithm; and (4) assess perioperative changes in nutritional status associated with chyle leakage. METHODS: This single-center, retrospective cohort study included patients who underwent multiport or single-port video-assisted thoracoscopic surgery, or robot-assisted thoracoscopic surgery at our institution between September 2009 and August 2024. Chylothorax was diagnosed based on visual and laboratory confirmation (pleural fluid triglyceride ≥ 110 mg/dL or high lymphocyte fraction), and was managed using a stepwise protocol including total parenteral nutrition (TPN), no-fat or low-fat diet, and pleurodesis as needed. If high output persisted or recurred, reoperation or thoracic duct ligation was considered. Patients were categorized into high-volume (HV) or low-volume chylothorax groups, using a threshold of 500 mL/day to reflect severity. The outcomes included chest tube duration, hospital stay, perioperative nutritional parameters (albumin, white blood cell count, and total lymphocyte count), and nutritional risk scores. RESULTS: Among the 1,038 patients included, 21 (2.0%) developed chylothorax. Risk factors for chylous leakage included right-sided tumors (p = 0.04), single-port or robotic approaches (p = 0.017), and a higher median number of dissected lymph nodes (p = 0.005) and N2 nodes (p = 0.001). Patients with chylothorax had a significantly longer chest tube duration (p < 0.001) and postoperative hospital stay (p < 0.001). Although conservative management was successful in most cases, the HV group had greater drainage volumes, more frequent pleurodesis, extended dietary interventions, and delayed recovery. Notable declines in albumin and total lymphocyte counts, and increased nutritional risk scores, underscored the metabolic burden posed by chylothorax. CONCLUSION: Chylothorax remains an important complication of MIS for lung cancer. Conservative measures are effective for many patients; however high-output chylothorax can prolong hospital stay and compromise nutritional status. Early recognition of the risk factors and judicious consideration of interventional and surgical options are essential.