Risk factors and nomogram prediction of postoperative incisional hernia following liver transplantation: A retrospective cohort study

Table 1 Baseline characteristics of patients, n (%)/median (interquartile range)

Characteristics	No incisional hernia	Developed incisional hernia	P value
n	435	76
Gender			0.287
Male	339 (66.3)	55 (10.8)
Female	96 (18.8)	21 (4.1)
Age	51 (44, 57)	66 (64, 67)	< 0.001
Smoking			0.379
No	297 (58.1)	48 (9.4)
Yes	138 (27)	28 (5.5)
Hepatitis			< 0.001
No	435 (85.1)	56 (11)
Yes	0 (0)	20 (3.9)
COPD			< 0.001
No	435 (85.1)	69 (13.5)
Yes	0 (0)	7 (1.4)
Ascites			< 0.001
No	429 (84)	67 (13.1)
Yes	6 (1.2)	9 (1.8)
Other1			0.106
No	402 (78.7)	66 (12.9)
Yes	33 (6.5)	10 (2)
Abdominal surgeries history2			< 0.001
No	435 (85.1)	73 (14.3)
Yes	0 (0)	3 (0.6)
Cancer3			< 0.001
No	339 (66.3)	37 (7.2)
Yes	96 (18.8)	39 (7.6)
Red blood cell counts, 1 × 1012/L	4.42 (3.925, 4.875)	4.15 (3.4075, 4.5875)	< 0.001
White blood cell counts, 1 × 109/L	5.81 (4.31, 7.76)	5.095 (3.7025, 6.545)	0.013
PLT (125-350), 1 × 109/L	172 (120, 238.5)	181 (103.75, 234.25)	0.539
ALB, g/L	41.8 (37.7, 44.7)	35.3 (32.275, 40.375)	< 0.001
Total bilirubin, μmol/L	20 (14, 32)	25.5 (14, 50)	0.021
ALT, U/L	19.7 (14.2, 30.95)	34.9 (22.45, 53.725)	< 0.001
AST, U/L	23.7 (17.8, 33.55)	44.8 (26.175, 71.5)	< 0.001
PT (8.8-13.8), seconds	15.3 (14.2, 16.5)	12.9 (11.875, 15.05)	< 0.001
INR (0.8-1.2)	1.05 (1, 1.16)	1.16 (1.0675, 1.3425)	< 0.001

¹The presence of other comorbidities.

²A history of prior abdominal operations.

³Liver transplantation performed for malignancy.

COPD: Chronic obstructive pulmonary disease; PLT: Platelet; ALB: Albumin; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; PT: Prothrombin time; INR: International normalized ratio.

Table 2 Univariate and multivariate Cox regression analysis of risk factors for incisional hernia after liver transplantation

Characteristics	Total (n)	Univariate analysis		Multivariate analysis
		Hazard ratio (95%CI)	P value	Hazard ratio (95%CI)	P value
Gender	487
Male	376	Reference
Female	111	1.225 (0.736-2.037)	0.435
Age	487	1.191 (1.148-1.235)	< 0.001	1.131 (1.075-1.191)	< 0.001
Smoking	487
No	328	Reference
Yes	159	1.147 (0.711-1.852)	0.574
Hepatitis	487
No	468	Reference		Reference
Yes	19	15.240 (8.958-25.926)	< 0.001	2.225 (1.058-4.682)	0.035
COPD	487
No	480	Reference		Reference
Yes	7	5.032 (2.291-11.054)	< 0.001	0.266 (0.089-0.792)	0.017
Ascites	487
No	472	Reference		Reference
Yes	15	6.538 (3.242-13.185)	< 0.001	5.687 (1.925-16.802)	0.002
Other1	487
No	446	Reference
Yes	41	1.396 (0.691-2.818)	0.353
Abdominal surgeries history2	487
No	484	Reference		Reference
Yes	3	25.832 (7.797-85.579)	< 0.001	2.182 (0.338-14.068)	0.412
Cancer3	487
No	359	Reference		Reference
Yes	128	2.810 (1.779-4.437)	< 0.001	1.116 (0.651-1.916)	0.689
Red blood cell counts, 1 × 1012/L	487	0.503 (0.373-0.678)	< 0.001	0.829 (0.592-1.163)	0.277
White blood cell counts, 1 × 109/L	487	0.887 (0.803-0.981)	0.020	0.902 (0.796-1.023)	0.108
PLT (125-350), 1 × 109/L	487	0.999 (0.996-1.002)	0.425
ALB, g/L	487	0.895 (0.864-0.927)	< 0.001	0.933 (0.886-0.982)	0.008
Total bilirubin, μmol/L	487	1.002 (1.000-1.004)	0.031	1.000 (0.997-1.002)	0.775
ALT, U/L	487	1.005 (1.003-1.007)	< 0.001	1.013 (1.004-1.021)	0.003
AST, U/L	487	1.002 (1.001-1.003)	< 0.001	0.996 (0.993-0.999)	0.023
PT (8.8-13.8), seconds	486	0.803 (0.750-0.861)	< 0.001	0.903 (0.816-0.999)	0.047
INR (0.8-1.2)	487	2.915 (1.616-5.257)	< 0.001	2.042 (0.735-5.674)	0.171

¹The presence of other comorbidities.

²A history of prior abdominal operations.

³Liver transplantation performed for malignancy.

COPD: Chronic obstructive pulmonary disease; PLT: Platelet; ALB: Albumin; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; PT: Prothrombin time; INR: International normalized ratio; CI: Confidence interval.