Table 2 Univariate and multivariate analyses of each factor’s ability in predicting conversion

Age [year]

0.276

–

 ≤ 60

Ref

 60 ~ 80

1.175(0.745–1.851)

 >80

1.962(0.850–4.529)

Sex

0.040^*

–

0.128

 Male

Ref

 Female

1.566(1.021–2.401)

BMI [Kg/m²]

0.551

–

  < 24

Ref

 24 ~ 28

1.014(0.638–1.611)

  > 28

0.270(0.063–1.149)

Diabetes (Yes/No)

0.789(0.411–1.514)

0.476

–

Hypertension (Yes/No)

0.758(0.468–1.230)

0.262

–

PUAS (Yes/No)

2.314(1.409–3.799)

0.001^*

4.014(2.077–7.755)

< 0.001^*

History of ERCP surgery (Yes/No)

1.310(0.519–3.302)

0.567

–

Pancreatitis (Yes/No)

0.306(0.072–1.299)

0.108

WBC[*10⁹/L]

0.739

–

  ≤ 10

Ref

  > 10

1.125(0.563–2.246)

ALB [g/L]

0.018^*

–

0.477

  ≤ 35

Ref

  > 35

0.578(0.367–0.910)

TBIL [μmol/L]

0.267

–

  ≤ 17.1

Ref

  > 17.1

0.786(0.513–1.203)

ALP [U/L]

0.921

–

  ≤ 125

Ref

  > 125

1.024(0.645–1.625)

ALT [U/L]

0.922

–

  ≤ 40

Ref

  > 40

1.024(0.639–1.640)

AST [U/L]

0.769

–

  ≤ 40

Ref

  > 40

1.069(0.685–1.667)

GGT [U/L]

> 0.95

–

  ≤ 50

Ref

  > 50

0.998(0.564–1.766)

Maximum diameter of CBD stone [mm]

< 0.001*

0.003^*

  < 12

Ref

Ref

  ≥ 12

2.635(1.705–4.073)

2.312(1.318–4.057)

CBD stone’s location

 Duodenal upper segment (Yes/No)

1.612(0.989–2.627)

0.055

–

 Duodenal posterior segment (Yes/No)

1.044(0.673–1.618)

0.848

–

 Pancreatic segment (Yes/No)

0.873(0.543–1.402)

0.573

–

 Medial wall of the duodenum (Yes/No)

4.588(2.406–8.748)

< 0.001^*

5.393(2.513–11.574)

< 0.001^*

The number of stones in CBD

0.711

–

 Negative/sludge

Ref

 Single

0.911(0.296–2.803)

 Multiple

1.096(0.361–3.330)

IHD stone (Yes/No)

1.991(1.220–3.249)

0.006^*

–

0.182

Thickening of gallbladder wall (Yes/No)

2.316(1505–3.564)

< 0.001^*

4.318(2.454–7.597)

< 0.001^*

Thickening of CBD wall (Yes/No)

6.037(3.195–11.411)

< 0.001^*

4.513(2.111–9.646)

< 0.001^*

Diameter of CBD

1.055(1.019–1.093)

0.002^*

–

0.153

Stone size/CBD size

< 0.001^*

0.026^*

  < 0.75

Ref

Ref

  ≥ 0.75

2.650(1.666–4.216)

1.909(1.078–3.378)

Surgery method

 Simultaneous LC (Yes/No)

0.689(0.389–1.221)

0.202

–

 Simultaneous LH (Yes/No)

4.521(2.624–7.789)

< 0.001^*

7.032(3.683–13.426)

< 0.001^*

 Laser lithotripsy (Yes/No)

2.536(0.749–8.586)

0.135