Low ligation has a lower anastomotic leakage rate after rectal cancer surgery

Table 1 Patient demographics

Variables	High ligation (n = 235)	Low ligation (n = 227)	P value
Gender, n (%)			0.356
Male	127 (54.0)	117 (51.5)
Female	108 (46.0)	110 (48.5)
Age (yr, mean ± SD)	57.9 ± 9.1	58.6 ± 8.9	0.57
BMI (kg/m2, mean ± SD)	24.1 ± 2.6	23.7 ± 3.1	0.761
Neoadjuvant therapy, n (%)	80 (34.0)	75 (33.0)	0.819
ASA score, n (%)			0.624
ASA I	80 (34.0)	69 (30.4)
ASA II	127 (54.0)	126 (55.5)
ASA III	28 (12.0)	32 (14.1)

SD: Standard deviation; BMI: Body mass index; ASA: American Society of Anesthesiologists.

Table 2 Surgical data and complications

Variables	High ligation (n = 235)	Low ligation (n = 227)	P value
Type of operation, n (%)			0.453
AR + anastomosis	218 (92.7)	216 (95.1)
AR + Hartmann's procedure	5 (2.1)	2 (0.9)
AR + anastomosis + ileostomy	12 (5.1%)	9 (4.0)
Conversion to open surgery, n (%)	4 (1.7%)	6 (2.6)
Operation time (min, mean ± SD)	163.1 ± 51.3	174.4 ± 61.8	0.142
Estimated blood loss (mL, mean ± SD)	47.5 ± 21.2	52.6 ± 23.7	0.363
Number of harvested lymph nodes (mean ± SD)	16.8 ± 6.2	13.7 ± 7.4	0.399
Transanal tube, n (%)	147 (62.5)	96 (42.3)	< 0.001
Anastomotic leakage, n (%)	24 (10.2)	6 (2.6)	0.001
Anastomotic bleeding, n (%)	4 (1.7)	3 (1.3)	0.738
Urinary dysfunction, n (%)	9 (3.8)	7 (3.1)	0.661
Time to first flatus (d, mean ± SD)	2.1 ± 0.6	1.9 ± 0.8	0.177
Hospital stay after operation (d, mean ± SD)	7.0 ± 1.2	6.3 ± 1.3	0.236

AR: Anterior resection.

Table 3 Pathological outcomes

Variables	High ligation (n = 235)	Low ligation (n = 227)	P value
Tumor size (cm, mean ± SD)	4 ± 0.7	4.1 ± 0.8	0.314
Tumor location, n (%)			0.114
Below the peritoneal reflection	127 (54.0)	106 (46.7)
Above the peritoneal reflection	108 (46.0)	121 (53.3)
Differentiation degree, n (%)			0.324
Poor	66 (28.1)	50 (22.0)
Moderate	146 (62.1)	153 (67.4)
Well	23 (9.8)	24 (10.6)
p-Stage, n (%)			0.184
I	24 (10.2)	19 (8.4)
II	95 (40.4)	111 (48.9)
III	116 (49.4)	97 (42.7)

Table 4 Stratification analysis of anastomotic leakage in the anterior resection + anastomosis group (n = 424)

Variables	High ligation (n = 218)	Low ligation (n = 216)	P value
AL patients, n (%)	24 (11.0)	6 (2.8)	0.001
Grade, n (%)			0.464
A	0	0
B	2 (0.1)	0
C	22 (10.1)	6 (2.8)
Onset of AL, n (%)			0.464
Early AL	22 (10.1)	6 (2.8)
Delayed AL	2 (0.1)	0

AL: Anastomotic leakage.

Table 5 Multivariate logistic regression analysis factors which might influence anastomotic leakage

Variables	P value	OR	95%CI
High or Low ligation	0.009	3.599	1.374-9.425
Age (< 65 yr or ≥ 65 yr)	0.032	2.494	1.080-5.760
ASA score	0.108	1.798	0.879-3.675
Neoadjuvant therapy	0.058	2.144	0.974-4.717
Gender	0.195	0.583	0.258-1.317
Transanal tube	0.180	1.754	0.772-3.985
Tumor location	0.031	2.715	1.098-5.760
pTNM	0.477	1.245	0.680-2.280

ASA: American Society of Anesthesiologists.

Table 6 Patients with diverting stoma

Variables	High ligation (n = 235)	Low ligation (n = 227)	P value
Stoma, n (%)			0.003
Yes	39 (16.5)	17 (7.5)
No	196 (83.5)	210 (92.5)