Results
There were 172 female and 230 male patients. The mean age was 61.1 ± 10.5 years (range of 25–86 years). Table 1 and Table 2 summarize the clinical and pathological data. The incidence of postoperative complications was 17.4% (70/402). The postoperative mortality was 0.5% (2/402). One patient died from respiratory failure caused by postoperative pneumonia and the other one died from postoperative bronchopleural fistula. The total number of LNs (N1 + N2) was 16.0 ± 5.9 (range of 5–52), and the number of N2 LNs was 9.5 ± 4.0 (range of 3–23). The incidences of postoperative upstaging from N0 to N1 and N2 disease were 7.7% (31/402) and 12.2% (49/402), respectively. Table 3 shows the number of LNs harvested from each N2 station.