The Association of Chylothorax With Aggressiveness of Lymph Node Management During Pulmonary Resection.

Abstract

Background: Chylothorax is a morbid and costly complication that can originate in lymph node resection beds. We hypothesized a close association between the occurrence of chylothorax and the extent and aggressiveness of lymph node dissection.

Methods: We conducted a nested case-control study of 1728 non-small cell lung cancer patients who underwent resection at our institution between January 2005 and July 2023. Cases were defined as patients who developed chylothorax. Each case was matched with 3 control patients who did not develop chylothorax, based on year of diagnosis, clinical N descriptor, presence of granulomatous lymph nodes, extent of resection, and tumor laterality. Using conditional logistic regression, we estimated risk ratios with 95% CIs to examine the association between the occurrence of chylothorax and several measures of the extent of lymph node resection.

Results: The incidence of chylothorax was 33 of 1728 (1.9%). In the matched groups, patients with chylothorax had higher rates of complete lymphadenectomy (82% vs 65%, P = .059) and systematic lymph node dissection as defined by International Association for the Study of Lung Cancer, European Society of Medical Oncology, and European Society of Thoracic Surgeons (85% vs 52%, P = .002). Station 2 was resected significantly more often in the chylothorax group (48.5% vs 29%, P = .04). The chylothorax group had a longer median in-hospital stay (7 vs 4 days, P = .003) and higher rates of reoperation (18% vs 1.0%, P = .006) and readmission (18% vs 5%, P = .03).

Conclusions: In matched groups, chylothorax is associated with several measures of more aggressive lymph node management and results in substantial postoperative morbidity. This finding provides additional support for more selective lymph node management approaches when resecting smaller, less solid, and less 18-fluorodeoxyglucose-avid tumors.