Unexpected doornail hilar lymph nodes during robot-assisted pulmonary resection: intraoperative challenges and...

Hilar lymph nodes with dense adhesion to the bronchus and pulmonary artery ("doornail" nodes) can be encountered unexpectedly during robot-assisted pulmonary resection. We report our experience managing these nodes and associated factors. This retrospective single-center cohort study included 1,185 patients undergoing robot-assisted pulmonary resection (March 2021-September 2024). Preoperative factors were analyzed using Firth penalized logistic regression in a clinically selected model (age, maximal voluntary ventilation [MVV], and tumor diameter). Operative time and blood loss were compared using robust regression models. Perioperative outcomes were compared descriptively between attempted separate dissection and en bloc stapling. Doornail hilar lymph nodes occurred in 48 of 1,185 patients (4.05%; 95% CI, 3.07-5.33%). Older age remained associated with this finding after adjusting for MVV and tumor diameter (adjusted OR per 10 years, 2.316; 95% CI, 1.533-3.596; P<0.001). Operative time was longer unadjusted (105 vs 92 min; P=0.027) but not after adjustment. Among these 48 patients, 45 (93.8%) received en bloc stapling with no blood loss exceeding 200 mL, transfusion, or prespecified in-hospital complication, whereas all 3 (6.3%) who underwent attempted separate dissection had substantial bleeding (700-2,400 mL), and 2 required transfusion. No conversion to thoracotomy occurred. Doornail hilar lymph nodes occurred in about 4% of patients; older age remained associated with this finding after adjusting for MVV and tumor diameter. Because strategy selection was non-random and groups differed in resection extent, comparative safety cannot be established; en bloc stapling after tissue thinning may be feasible when a node cannot be safely separated.