Complete anatomic segmentectomy shows improved oncologic outcomes compared to incomplete anatomic segmentectomy.

Abstract

To compare oncologic outcomes after segmentectomy with division of segmental bronchus, artery and vein (complete anatomic segmentectomy) versus segmentectomy with division of <3 segmental structures (incomplete anatomic segmentectomy). We conducted a single-centre, retrospective analysis of patients undergoing segmentectomy from March 2005 to May 2020. Operative reports were audited to classify procedures as complete or incomplete anatomic segmentectomy. Patients who underwent neoadjuvant therapy or pulmonary resection beyond indicated segments were excluded. Survival was estimated with Kaplan-Meier models and compared using log-rank tests. Cox proportional hazards models were used to estimate hazard ratios (HRs) for death. Cumulative incidence functions for loco-regional recurrence were compared with Gray's test, with death considered a competing event. Cox and Fine-Gray models were used to estimate cause-specific and subdistribution HRs, respectively, for loco-regional recurrence. Of 390 cases, 266 (68.2%) were complete and 124 were incomplete anatomic segmentectomy. Demographics, pulmonary function, tumour size, stage and perioperative outcomes did not significantly differ between groups. Surgical margins were negative in all but 1 case. Complete anatomic segmentectomy was associated with improved lymph node dissection (5 vs 2 median nodes sampled; P < 0.001). Multivariable analysis revealed reduced incidence of loco-regional recurrence (cause-specific HR = 0.42; 95% confidence interval 0.22-0.80; subdistribution HR = 0.43; 95% confidence interval 0.23-0.81), and non-significant improvement in overall survival (HR = 0.66; 95% confidence interval: 0.43-1.00) after complete versus incomplete anatomic segmentectomy. This single-centre experience suggests complete anatomic segmentectomy provides superior loco-regional control and may improve survival relative to incomplete anatomic segmentectomy. We recommend surgeons perform complete anatomic segmentectomy and lymph node dissection whenever possible.