Table 2 Comparisons of clinical characteristics by gender

Age (%)

 ≤ 65 years

175 (74.5%)

175 (66.3%)

350 (70.1%)

 > 65 years

60 (25.5%)

89 (33.7%)

149 (29.9%)

Age (years), mean ± SD

57.5 ± 11.1

59.7 ± 10.6

58.7 ± 10.9

BMI

 < 25 kg/m²

173 (73.6%)

202 (76.5%)

375 (75.2%)

 ≥ 25 kg/m²

47 (20%)

37 (14%)

84 (16.8%)

 Missing

15 (6.4%)

25 (9.5%)

40 (8%)

 Smoking

2 (0.9%)

85 (32.2%)

87 (17.4%)

Diabetes mellitus (%)

 Yes

18 (7.7%)

19 (7.2%)

37 (7.4%)

 No

217 (92.3%)

245 (92.8%)

462 (92.6%)

Hypertension (%)

 Yes

33 (14%)

41 (15.5%)

74 (14.8%)

 No

202 (86%)

223 (84.5%)

425 (85.2%)

Previous abdominal surgery (%)

 Yes

53 (22.6%)

30 (11.4%)

83 (16.6%)

 No

182 (77.4%)

234 (88.6%)

416 (83.4%)

 Preoperative serum albumin(g/L), mean ± SD

41.2 ± 3.3

40.9 ± 3.3

41 ± 3.3

Neoadjuvant therapy (%)

 Yes

0 (0%)

9 (3.4%)

9 (1.8%)

 No

235 (100%)

255 (96.6%)

490 (98.2%)

ASA score

 III–IV

8 (3.4%)

16 (6.1%)

24 (4.8%)

 I–II

227 (96.6%)

248 (93.9%)

475 (95.2%)

Operation time (%)

 < 180 min

185 (78.7%)

203 (76.9%)

388 (77.8%)

 ≥ 180 min

50 (21.3%)

61 (23.1%)

111 (22.2%)

Tumor location (%)

 ≤ 5 cm

65 (27.7%)

67 (25.4%)

132 (26.5%)

 > 5 cm

170 (72.3%)

197 (74.6%)

367 (73.5%)

AJCC stage (%)

 0–II

134 (57%)

172(65.2%)

306(61.3%)

 III–IV

101 (43%)

92(34.8%)

193(38.7%)

Type of anastomosis (%)

 Stapled

222 (94.9%)

243 (97%)

465 (6.8%)

 Hand-sewn

13 (5.1%)

21 (3%)

34 (6.8%)

Estimated blood loss (%)

 ≤ 300 ml

223 (96.7%)

256 (87.5%)

479 (96%)

 > 300 ml

12 (3.3%)

8 (12.5%)

20 (4%)

Surgery approach (%)

 Laparoscopic surgery

190 (80.9%)

223 (84.5%)

413 (82.8%)

 Open surgery

39 (16.6%)

37 (14%)

76 (15.2%)

 Conversion

6 (2.6%)

4 (1.5%)

10 (2%)

Postoperative serum albumin (g/L), mean ± SD

28.9 ± 3.5

29.5 ± 3.5

29.3 ± 3.5

The average relative decline in serum albumin

29.5% ± 8.8%

27.6% ± 8.7%

28.5% ± 8.8%

Anastomotic leakage

15 (6.4%)

25 (9.5%)

40 (8%)