Table 3. Association between patient characteristics and conversion to thoracotomy.
| Estimated variables | Total (N=475) | Conversion to thoracotomy | P value | |
|---|---|---|---|---|
| Yes (N=16) | No (N=459) | |||
| Mean age, years (SD) | 62.67±8.52 | 69.81±6.54 | 62.42±8.48 | 0.001 |
| Age categorization, n (%) | ||||
| Age ≤65 years | 298 (62.7) | 6 (37.5) | 292 (63.6) | 0.034 |
| Age >65 years | 177 (37.3) | 10 (62.5) | 167 (36.4) | |
| Gender (Male, %) | 278 (58.5) | 13 (81.3) | 265 (57.7) | 0.061 |
| Mean BMI, kg/m2 (SD) | 23.59±3.07 | 24.91±2.29 | 23.54±3.08 | 0.080 |
| BMI categorization, n (%) | ||||
| Underweight/normal (BMI <25.0 kg/m2) | 326 (68.6) | 10 (62.5) | 316 (68.8) | 0.59 |
| Overweight/obese (BMI ≥25.0 kg/m2) | 149 (31.4) | 6 (37.5) | 143 (31.2) | |
| Mean BSA, m2 (SD) | 1.74±0.16 | 1.79±0.16 | 1.74±0.16 | 0.22 |
| BSA categorization, n (%) | ||||
| BSA ≤1.73 m2 | 239 (50.3) | 3 (18.8) | 236 (51.4) | 0.010 |
| BSA >1.73 m2 | 236 (49.7) | 13 (81.3) | 223 (48.6) | |
| Smoking history | 227 (47.8) | 11 (68.8) | 216 (47.1) | 0.088 |
| COPD, n (%) | 110 (23.2) | 10 (62.5) | 100 (21.8) | <0.001 |
| Tuberculosis, n (%) | 39 (8.2) | 4 (25.0) | 35 (7.6) | 0.043 |
| Preoperative respiratory infection, n (%) | 43 (9.1) | 7 (43.8) | 36 (7.8) | <0.001 |
| Hypertension, n (%) | 168 (35.4) | 5 (31.3) | 163 (35.5) | 0.73 |
| Diabetes mellitus, n (%) | 51 (10.7) | 1 (6.3) | 50 (10.9) | 0.86 |
| Coronary heart disease, n (%) | 55 (11.6) | 3 (18.8) | 52 (11.3) | 0.61 |
| Renal insufficiency, n (%) | 34 (7.2) | 3 (18.8) | 31 (6.8) | 0.18 |
| Severe liver diseases, n (%) | 51 (10.7) | 2 (12.5) | 49 (10.7) | 1.0 |
| Previous malignancy, n (%) | 28 (5.9) | 3 (18.8) | 25 (5.4) | 0.093 |
| Steroid use, n (%) | 22 (4.6) | 2 (12.5) | 20 (4.4) | 0.36 |
| Neoadjuvant induction therapy, n (%) | 35 (7.4) | 2 (12.5) | 33 (7.2) | 0.76 |
| Adjuvant chemotherapy, n (%) | 161 (33.9) | 5 (31.3) | 156 (34.0) | 0.82 |
| Tumor location, n (%) | ||||
| Right upper lobe | 163 (34.3) | 5 (31.3) | 158 (34.4) | 0.84 |
| Left upper lobe | 94 (19.8) | 2 (12.5) | 92 (20.0) | |
| Right lower lobe | 99 (20.8) | 4 (25.0) | 95 (20.7) | |
| Left lower lobe | 66 (13.9) | 2 (12.5) | 64 (13.9) | |
| Right middle lobe | 53 (11.2) | 3 (18.8) | 50 (10.9) | |
| Pleural invasion, n (%) | ||||
| None | 223 (46.9) | 5 (31.3) | 218 (47.5) | 0.19 |
| Visceral | 219 (46.1) | 8 (50.0) | 211 (46.0) | |
| Parietal | 33 (6.9) | 3 (18.8) | 30 (6.5) | |
| Pleural adhesion, n (%) | ||||
| None | 205 (43.2) | 2 (12.5) | 203 (44.2) | <0.001 |
| Light | 148 (31.2) | 1 (6.3) | 147 (32.0) | |
| Moderate | 79 (16.6) | 9 (56.3) | 70 (15.3) | |
| Severe/atresia | 43 (9.1) | 4 (25.0) | 39 (8.5) | |
| Pulmonary fissure status, n (%) | ||||
| Complete fissures | 318 (66.9) | 6 (37.5) | 312 (68.0) | 0.011 |
| Incomplete fissures | 157 (33.1) | 10 (62.5) | 147 (32.0) | |
| Histology, n (%) | ||||
| Adenocarcinoma | 365 (76.8) | 12 (75.0) | 353 (76.9) | 0.60 |
| Squamous cell carcinoma | 88 (18.5) | 4 (25.0) | 84 (18.3) | |
| Adeno-squamous carcinoma | 13 (2.7) | 0 (0.0) | 13 (2.8) | |
| Others | 9 (1.9) | 0 (0.0) | 9 (2.0) | |
| Differentiation degree, n (%) | ||||
| Low | 84 (17.7) | 1 (6.3) | 83 (18.1) | 0.38 |
| Moderate/high | 391 (82.3) | 15 (93.7) | 376 (81.9) | |
| Tumor invasion (T status), n (%) | ||||
| T1-2 | 452 (95.2) | 13 (81.3) | 439 (95.6) | 0.041 |
| T3-4 | 23 (4.8) | 3 (18.8) | 20 (4.4) | |
| Lymph node metastasis (N status), n (%) | ||||
| N1-2 | 98 (20.6) | 3 (18.8) | 95 (20.7) | 0.85 |
| N0 | 377 (79.4) | 13 (81.3) | 364 (79.3) | |
| TNM stage, n (%) | ||||
| I | 349 (73.4) | 11 (68.8) | 338 (73.7) | 0.81 |
| II | 70 (14.7) | 2 (12.5) | 68 (14.8) | |
| IIIa | 56 (11.8) | 3 (18.8) | 53 (11.5) | |
BMI, body mass index; BSA, body surface area, COPD, chronic obstructive pulmonary disease; SD, standard deviation.