Table 1 Patients characteristics

Age (years), mean ± SD

58.6 ± 10.9

59.3 ± 10.5

58.7 ± 10.9

Gender (%)

 Female

220 (47.9%)

15 (37.5%)

235 (47.1%)

 Male

239 (52.1%)

25 (62.5%)

264 (52.9%)

BMI

 < 25 kg/m²

344 (74.9%)

31 (77.5%)

375 (75.2%)

 ≥ 25 kg/m²

76 (16.6%)

8 (20%)

84 (16.8%)

 Missing

39 (8.5%)

1 (2.5%)

40 (8%)

Diabetes mellitus (%)

 Yes

35 (7.6%)

2 (5%)

37 (7.4%)

 No

424 (92.4%)

38 (95%)

462 (92.6%)

Hypertension (%)

 Yes

66 (14.4%)

8 (20%)

74 (14.8%)

 No

393 (85.6%)

32 (80%)

425 (85.2%)

Previous abdominal surgery (%)

 Yes

77 (16.8%)

6 (15%)

83 (16.6%)

 No

382 (83.2%)

34 (85%)

416 (83.4%)

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

41 ± 3.3

41.4 ± 3

41 ± 3.3

Neoadjuvant therapy (%)

 Yes

9 (2%)

0 (0%)

9 (1.8%)

 No

450 (98%)

40 (100%)

490 (98.2%)

ASA score

 III–IV

22 (4.8%)

2 (5%)

24 (4.8%)

 I–II

437 (95.2%)

38 (95%)

475 (95.2%)

Operation time (%)

 < 180 min

357 (77.8%)

31 (77.5%)

388 (77.8%)

 ≥ 180 min

102 (102)

9 (22.5%)

111 (22.2%)

Tumor location (%)

 ≤ 5 cm

119 (25.9%)

13 (32.5%)

132 (26.5%)

 > 5 cm

340 (74.1%)

27 (67.5%)

367 (73.5%)

AJCC stage (%)

 0–II

283 (61.7%)

23 (57.5%)

306 (61.3%)

 III–IV

176 (38.3%)

17 (42.5%)

193 (38.7%)

Type of anastomosis (%)

 Stapled

429 (93.5%)

36 (90%)

465 (6.8%)

 Hand-sewn

30 (6.5%)

4 (10%)

34 (6.8%)

Estimated blood loss (%)

 ≤ 300 ml

444 (96.7%)

35 (87.5%)

479 (96%)

 > 300 ml

15 (3.3%)

5 (12.5%)

20 (4%)

Surgery approach (%)

 Laparoscopic surgery

380 (82.8%)

33 (82.5%)

413 (82.8%)

 Open surgery

69 (15%)

7 (17.5%)

76 (15.2%)

 Conversion

10 (2.2%)

0 (0%)

10 (2%)

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

29.3 ± 3.5

28.3 ± 3.2

29.2 ± 3.5

The average relative decline in serum albumin

28.2% ± 8.8%

31.5% ± 8%

28.5% ± 8.8%