Table 2 Frequency of assessed lymph nodes and number of assessed lymph nodes by stations and surgical approach

frequency of stations assessed

N1

472

59.6%

502

63.4%

 hilar (#10)

131

66.2%

153

77.3%

0.02

 interlobar (#11)

168

84.8%

167

84.3%

1.00

 lobar (#12)

13

6.6%

18

9.1%

0.45

 intrapulmonary

160

80.8%

164

82.8%

0.69

N2

554

69.9%

567

71.6%

 paratracheal (#2,#4)

125

63.1%

129

65.2%

0.75

 aortopulmonary window (#5,#6)

76

38.4%

76

38.4%

1.00

 subcarinal (#7)

182

91.9%

186

93.9%

0.56

 pulmonary ligament/paraesophageal (#8,#9)

171

86.4%

176

88.9%

0.54

mean

sd

mean

sd

p-value

# of LN assessed

N1

5.8

4.0

7.4

4.6

0.001

 hilar (#10)

1.5

1.8

1.9

1.8

0.043

 interlobar (#11)

2.2

1.9

2.4

2.1

0.23

 lobar (#12)

0.2

0.9

0.2

0.9

0.79

 intrapulmonary

2.6

2.3

3.5

3.8

0.007

N2

8.4

4.8

10.2

7.0

0.003

 paratracheal (#2,#4)

2.9

3.4

3.8

4.5

0.033

 aortopulmonary window (#5,#6)

1.1

1.9

1.2

2.1

0.77

 subcarinal (#7)

2.6

2.2

3.0

2.7

0.15

 pulmonary ligament/paraesophageal (#8,#9)

2.0

1.7

2.4

2.2

0.03

overall stations assessed

6.1

1.1

6.5

1.2

0.002

overall LN count

15.5

6.8

19.0

9.2

< 0.0001

mean

sd

mean

sd

p-value

# of affected stations

 overall

0.21

0.73

0.30

0.77

0.26

 N1 LN

0.14

0.44

0.22

0.55

0.09

 N2 LN

0.08

0.40

0.08

0.35

1.00

# of affected LN

 overall

0.38

1.64

0.51

1.66

0.45

 N1 LN

0.24

1.00

0.40

1.31

0.16

 N2 LN

0.15

0.87

0.11

0.51

0.57