Effect of the extrahepatic bile duct anatomy on choledocholithiasis and its clinical significance

Table 1 Univariate analysis for general data

Variable	Without CBD stones (n = 124)	With CBD stones (n = 108)	P value
Age (yr)	50.88 ± 15.60	55.06 ± 18.00	0.060
Sex, n (%)			0.575
Female	70 (56.45)	57 (52.78)
Male	54 (43.55)	51 (47.22)
BMI (kg/m2)	23.79 ± 3.78	23.62 ± 3.71	0.732
Hypertension, n (%)	19 (15.32)	9 (8.33)	0.103
Diabetes, n (%)	12 (9.68)	5 (4.63)	0.141
Hyperlipidemia, n (%)	23 (18.55)	6 (5.56)	0.003
ALT (U/L)	24.50 (16.00, 45.25)	100.45 (32.00, 216.25)	< 0.001
AST (U/L)	24.00 (19.00, 39.25)	53.00 (26.00, 130.75)	< 0.001
ALP (U/L)	84.50 (70.00, 116.50)	160.80 (104.50, 275.25)	< 0.001
GGT (U/L)	43.00 (23.00, 118.25)	251.50 (121.50, 576.50)	< 0.001
DBil (µmol/L)	4.25 (2.98, 6.60)	10.00 (4.90, 29.48)	< 0.001
IBil (µmol/L)	9.35 (6.47, 13.38)	10.70 (7.50, 15.20)	0.167

BMI: Body mass index; ALT: Alanine transaminase; AST: Aspartate transaminase; ALP: Alkaline phosphatase; GGT: γ-glutamyl transferase; DBil: Direct bilirubin; IBil: Indirect bilirubin; CBD: Common bile duct.

Table 2 Univariate analysis for anatomical factors of the extrahepatic bile duct

Variable	Without CBD stones (n = 124)	With CBD stones (n = 108)	P value
CHD diameter (mm)	4.10 (3.20, 6.03)	9.40 (6.88, 12.50)	< 0.001
CD diameter (mm)	3.10 (2.40, 4.93)	5.85 (3.70, 8.50)	< 0.001
CBD diameter (mm)	5.00 (3.80, 6.70)	10.35 (8.10, 13.00)	< 0.001
CHD length (mm)	20.51 ± 8.88	25.12 ± 12.58	0.002
CD length (mm)	26.10 ± 12.76	35.83 ± 21.69	< 0.001
CBD length (mm)	50.46 ± 12.87	52.65 ± 13.84	0.212
CBD angulation (°)	138.94 ± 19.19	112.79 ± 19.12	< 0.001
Oblique angle of the CBD (°)	60.12 ± 18.54	47.08 ± 19.85	< 0.001
Insertion position of CD, n (%)
Anterior	15 (12.10)	21 (19.44)	0.123
Posterior	8 (6.45)	33 (30.56)	< 0.001
Lateral	95 (76.61)	50 (46.30)	< 0.001
Medial	6 (4.84)	4 (3.70)	0.920
Upper	85 (68.55)	57 (52.78)	0.014
Middle	38 (30.65)	48 (44.44)	0.030
Lower	1 (0.81)	3 (2.78)	0.519
Route of CD, n (%)
Linear type	15 (12.10)	8 (7.41)	0.233
Curved type	92 (74.19)	80 (74.07)	0.983
Spiral type	8 (6.45)	14 (12.96)	0.091
Complex type	9 (7.26)	6 (5.56)	0.599
Route of CBD, n (%)
Polyline type	118 (95.16)	98 (90.74)	0.185
S type	6 (4.84)	10 (9.26)	0.185

CHD: Common hepatic duct; CD: Cystic duct; CBD: Common bile duct.

Table 3 Independent risk factors for common bile duct stones in multivariate analysis

Variable	aOR (95%CI)	Adjusted P value
CHD diameter	1.43 (1.07-1.92)	0.016
CBD diameter	1.68 (1.27-2.23)	< 0.001
CHD length	0.92 (0.84-0.99)	0.034
CBD angulation	0.92 (0.89-0.95)	< 0.001

aOR: Adjusted odds ratio; CHD: Common hepatic duct; CBD: Common bile duct.