Table 1 Patients’ characteristics
|  | Overall (n=173) | VR− group (n=132) | VR+ group (n=41) | P-value |
|---|---|---|---|---|
Age (years), mean | 68.7±10.8 | 68.6±11.1 | 69±10.0 | 0.850 |
Male/female | 84/89 | 67/65 | 17/24 | 0.298 |
BMI (kg/m2), mean | 25.9±3.9 | 26.6±3.9 | 23±3.8 | 0.063 |
ASA class | ||||
 I–II (%) | 85 (49.1) | 61 (46.2) | 24 (58.5) | 0.168 |
 III (%) | 88 (50.9) | 71 (53.8) | 17 (41.5) | 0.168 |
Comorbidities | ||||
 Diabetes (%) | 24 (13.9) | 16 (12.1) | 8 (19.5) | 0.232 |
 Cardiovascular disease (%) | 25 (14.5) | 20 (15.2) | 5 (12.2) | 0.638 |
 COPD (%) | 2 (1.2) | 2 (1.5) | 0 | 0.428 |
 Obstructive jaundice (%) | 43 (24.9) | 25 (18.9) | 18 (43.9) | 0.001 |
Preoperative biliary drainage (%) | 20 (11.6) | 10 (7.6) | 10 (24.4) | 0.003 |
Tumour stage | ||||
 I (%) | 47 (27.2) | 39 (29.5) | 8 (19.5) | 0.207 |
 II (%) | 70 (40.5) | 55 (41.7) | 15 (36.6) | 0.563 |
 III (%) | 47 (27.2) | 32 (24.2) | 15 (36.6) | 0.121 |
 IV (%) | 9 (5.2) | 6 (4.5) | 3 (7.3) | 0.485 |
Degree of tumour contact at CT | ||||
 < 180° (%) | 31 (17.9) | – | 31 (75.6) |  |
 > 180° (%) | 10 (5.8) | – | 10 (24.4) |  |