Risk factors for prolonged postoperative ileus in elderly patients undergoing laparoscopic radical resection for colorectal cancer

Table 1 Clinical baseline characteristics and pathological data of patients, n (%)

Baseline characteristics and pathological data	n = 167
Sex
Male	72 (43.1)
Female	95 (56.9)
Age (years)	71.4 ± 6.6
BMI (kg/m2)	23.9 ± 3.3
Smoking history
Yes	110 (65.9)
No	57 (34.1)
Preoperative CEA (ng/mL)	3.78 (2.13-8.88)
Preoperative albumin (g/L)	38.3 (35.9-41.2)
History of abdominal surgery	27 (16.2)
mFI-5 ≥ 2	71.0 (42.5)
Coronary heart disease	26 (15.6)
Operation time (minute)	173.6 ± 53.3
AJCC staging
I	26 (15.6)
II	72 (43.1)
III	69 (41.3)
Tumor location
Rectal cancer	128 (76.7)
Colon cancer	39 (23.4)
Lymphovascular/perineural invasion	48 (28.7)
PPOI	49 (29.3)

BMI: Body mass index; CEA: Carcinoembryonic antigen; mFI-5: Modified 5-item Frailty Index; AJCC: American Joint Committee on Cancer; PPOI: Prolonged postoperative ileus.

Table 2 Comparison between non-prolonged postoperative ileus and prolonged postoperative ileus groups, n (%)

Variable	Non-PPOI (n = 118)	PPOI (n = 49)	SMD	P value
Sex			-	0.520
Male	49 (41.5)	23 (46.9)
Female	69 (58.5)	26 (53.1)
Age (years)	71.7 ± 5.4	70.9 ± 8.8	0.113	0.504
BMI (kg/m2)	23.8 ± 3.3	24.2 ± 3.2	0.138	0.415
Smoking history	40 (33.9)	17 (34.7)	-	0.921
History of abdominal surgery	18 (15.3)	9 (18.4)	-	0.619
Coronary heart disease	19 (16.1)	7 (14.3)	-	0.768
mFI-5 ≥ 2	40 (33.9)	31 (63.3)	-	< 0.001
Preop CEA (ng/mL)	3.74 (2.09-10.3)	4.33 (2.52-7.42)	0.104	0.699
Preoperative albumin (g/L)	38.35 (36.1-41.2)	38 (35.3-41.1)	0.133	0.684
AJCC staging			-	0.251
I	15 (12.7)	11 (22.5)
II	54 (45.8)	18 (36.7)
III	49 (41.5)	20 (40.8)
ASA score			-	0.080
I	2 (1.7)	1 (2)
II	87 (73.7)	28 (57.1)
III	29 (24.6)	20 (40.8)
Auxiliary incision length (cm)	5 (5-5)	5 (5-5)	0.120	0.401
Operation time (minute)	176 ± 50	168 ± 60.9	0.151	0.374
Tumor location			-	0.167
Rectal cancer	87 (73.7)	41 (83.7)
Colon cancer	31 (26.3)	8 (16.3)
Lymphovascular/perineural invasion	36 (30.5)	12 (24.5)	-	0.434
Postoperative opioid use			-	0.008
Yes	39 (33.1)	27 (55.1)
No	79 (66.9)	22 (44.9)
Postoperative albumin (g/L)	32.7 (31-35.08)	32.06 (30.3-33.96)	0.093	0.129
POD 1 fluid (mL)	3611 (2900-4100)	3660 (2766-4130)	0.026	0.934
POD 2 fluid (mL)	3494 (2880-3930)	3300 (2844-3890)	0.175	0.340
POD 3 fluid (mL)	3465 (2780-4000)	3320 (2800-3936)	0.124	0.566
POD 1 K+ (mmol/L)	4.265 (4-4.5)	4.1 (3.63-4.4)	0.499	0.012
POD 1 Ca2+ (mmol/L)	2.03 (1.96-2.12)	2.01 (1.94-2.11)	0.085	0.402
POD 1 NLR	9.035 (7.6-12.6)	8.4 (6.91-11.38)	0.179	0.141
POD 1 PNI	37.54 (35.1-40.52)	37.55 (35.11-39.9)	0.025	0.965
POD 1 SII	1866.215 (1321.88-2471.95)	1683.44 (1156.09-2238.31)	0.274	0.174
POD 1 PIV	1238.155 (749.32-2038.9)	1071.18 (704.18-1790.47)	0.054	0.551

SMD: Standardized mean differences; BMI: Body mass index; Pre-op CEA: Preoperative carcinoembryonic antigen; mFI-5: Modified 5-item Frailty Index; PPOI: Prolonged postoperative ileus; ASA: American Society of Anesthesiologists; POD 1: Postoperative day 1; NLR: Neutrophil-to-lymphocyte ratio; PNI: Prognostic nutritional index; SII: Systemic immune-inflammation index; PIV: Pan-immune-inflammation value.

Table 3 Univariate and multivariate logistic regression analysis of risk factors for prolonged postoperative ileus, n (%)

Variable	Univariable analysis		Multivariable analysis
	OR (95%CI)	P value	OR (95%CI)	P value
Sex
Male	Reference	-
Female	0.80 (0.41-1.57)	0.520
Age (years)	0.98 (0.94-1.03)	0.506
BMI (kg/m2)	1.04 (0.94-1.16)	0.413
Smoking history	1.04 (0.51-2.09)	0.921
History of abdominal surgery	1.25 (0.52-3.01)	0.619
Coronary heart disease	0.87 (0.34-2.22)	0.768
mFI-5 ≥ 2	3.36 (1.68-6.73)	0.001	2.31 (1.10-4.86)	0.028
Preop CEA (ng/mL)	0.99 (0.98-1.01)	0.546
Preoperative albumin (g/L)	1.02 (0.96-1.09)	0.443
AJCC staging
I	Reference	-
II	0.45 (0.18-1.17)	0.101
III	0.56 (0.22-1.42)	0.220
ASA score
I	Reference	-
II	0.64 (0.06-7.37)	0.723
III	1.38 (0.12-16.26)	0.798
Auxiliary incision length (cm)	0.82 (0.48-1.42)	0.484
Operation time (minute)	1.00 (0.99-1.00)	0.373
Tumor location
Rectal cancer	Reference	-
Colon cancer	0.55 (0.23-1.3)	0.171
Lymphovascular/perineural invasion	0.74 (0.35-1.58)	0.435
Postoperative opioid use
Yes	2.49 (1.26-4.91)	0.009	2.39 (1.14-5.01)	0.021
No	Reference	-
Postoperative albumin (g/L)	0.98 (0.9-1.06)	0.584
POD 1 fluid (per mL)	1.00 (0.97-1.04)	0.878
POD 2 fluid (per mL)	0.98 (0.93-1.02)	0.303
POD 3 fluid (per mL)	0.99 (0.96-1.02)	0.501
POD 1 K+ (mmol/L)	0.34 (0.16-0.72)	0.005
≥ 3.61	0.14 (0.05-0.41)	< 0.001	0.17 (0.05-0.55)	0.003
< 3.61	Reference	-
POD 1 Ca2+ (mmol/L)	0.55 (0.05-5.71)	0.614
POD 1 NLR	0.96 (0.90-1.03)	0.293
POD 1 PNI	1.00 (0.93-1.06)	0.880
POD 1 SII (per 100)	0.97 (0.94-1.01)	0.114
POD 1 PIV (per 100)	0.99 (0.96-1.03)	0.749

BMI: Body mass index; Pre-op CEA: Preoperative carcinoembryonic antigen; mFI-5: Modified 5-item Frailty Index; PPOI: Prolonged postoperative ileus; ASA: American Society of Anesthesiologists; POD 1: Postoperative day 1; NLR: Neutrophil-to-lymphocyte ratio; PNI: Prognostic nutritional index; SII: Systemic immune-inflammation index; PIV: Pan-immune-inflammation value; OR: Odds ratio; CI: Confidence interval.