Table 1. Baseline and clinical characteristics.
| Variables | Unmatched groups | Matched groups | |||||
|---|---|---|---|---|---|---|---|
| T-RAMIE (N=144) | H-RAMIE (N=70) | P value | T-RAMIE (N=49) | H-RAMIE (N=49) | P value | ||
| Age (years) | 65.3±8.8 | 65.5±8.4 | 0.907 | 65.1±8.8 | 65.2±9.0 | 0.956 | |
| Sex (male) (n, %) | 133 (92.4) | 62 (88.6) | 0.361 | 43 (87.8) | 44 (89.8) | 0.739 | |
| BMI (kg/m2) | 23.0±3.1 | 23.6±3.3 | 0.164 | 23.2±3.8 | 23.7±3.0 | 0.469 | |
| Smoking status (n, %) | 0.046 | 0.161 | |||||
| Never smoker | 19 (13.2) | 15 (21.4) | 9 (18.4) | 9 (18.4) | |||
| Ex-smoker | 70 (48.6) | 22 (31.4) | 23 (46.9) | 13 (26.5) | |||
| Current smoker | 55 (38.2) | 33 (47.2) | 17 (34.7) | 27 (55.1) | |||
| Grade of dysphagia (n, %) | 0.626 | 0.885 | |||||
| 0 | 101 (70.1) | 45 (64.3) | 33 (67.3) | 33 (67.3) | |||
| 1 | 28 (19.4) | 15 (21.4) | 9 (18.4) | 10 (20.4) | |||
| ≥2 | 15 (10.5) | 10 (14.3) | 7 (14.3) | 6 (12.3) | |||
| ECOG PS (n, %) | 0.056 | 0.587 | |||||
| 0 | 104 (72.2) | 41 (58.6) | 34 (69.4) | 30 (61.2) | |||
| 1 | 39 (27.1) | 29 (41.4) | 14 (28.6) | 19 (38.8) | |||
| 2 | 1 (0.7) | 0 | 1 (2.0) | 0 | |||
| Comorbidities (n, %) | |||||||
| Hypertension | 56 (38.9) | 28 (40) | 0.876 | 17 (34.7) | 20 (40.8) | 0.532 | |
| Diabetes mellitus | 30 (20.8) | 10 (14.3) | 0.249 | 7 (14.3) | 7 (14.3) | 1.000 | |
| COPD | 12 (8.3) | 6 (8.6) | 0.953 | 1 (2.0) | 3 (6.1) | 0.317 | |
| Liver cirrhosis | 2 (1.4) | 5 (7.1) | 0.039 | 2 (4.1) | 3 (6.1) | 0.655 | |
| Renal disease | 2 (1.4) | 2 (2.9) | 0.599 | 2 (4.1) | 1 (2.0) | 0.564 | |
| Angina | 9 (6.3) | 7 (10.0) | 0.483 | 2 (4.1) | 3 (6.1) | 0.655 | |
| Stroke | 11 (7.6) | 8 (11.4) | 0.510 | 4 (8.2) | 7 (14.3) | 0.317 | |
| CCI (n, %) | 0.695 | 0.937 | |||||
| 0 | 91 (63.2) | 40 (57.1) | 32 (65.3) | 29 (59.2) | |||
| 1 | 32 (22.2) | 18 (25.7) | 10 (20.4) | 16 (32.6) | |||
| ≥2 | 21 (14.6) | 12 (17.2) | 7 (14.3) | 4 (8.2) | |||
| FEV1 (% of predicted value) | 102.3±16.6 | 99.5±17.7 | 0.278 | 106.1±17.6 | 101.9±18.5 | 0.259 | |
| Location of tumour (n, %) | 0.003 | 0.858 | |||||
| Cervical | 1 (0.7) | 1 (1.0) | 1 (2.0) | 1 (20.) | |||
| Upper thoracic | 20 (13.9) | 9 (12.9) | 6 (12.3) | 6 (12.3) | |||
| Mid thoracic | 98 (68.0) | 33 (47.1) | 30 (61.2) | 29 (59.2) | |||
| Lower thoracic | 25 (17.4) | 27 (38.6) | 12 (24.5) | 13 (26.5) | |||
| Clinical T stage (n, %) | 0.018 | 0.743 | |||||
| 1 | 69 (47.9) | 24 (34.3) | 24 (49.0) | 21 (42.9) | |||
| 2 | 50 (34.7) | 22 (31.4) | 11 (22.4) | 15 (30.6) | |||
| 3 | 25 (17.4) | 24 (34.3) | 14 (28.6) | 13 (26.5) | |||
| Clinical N stage (n, %) | 0.006 | 0.275 | |||||
| 0 | 98 (68.1) | 34 (48.6) | 31 (63.3) | 26 (53.1) | |||
| N+ | 46 (31.9) | 36 (51.4) | 18 (36.7) | 23 (46.9) | |||
| Neoadjuvant treatment (n, %) | 35 (24.3) | 25 (35.7) | 0.081 | 14 (28.6) | 16 (32.7) | 0.637 | |
| CCRT | 31 (21.5) | 25 (35.7) | 14 (28.6) | 16 (32.7) | |||
| CTx only | 3 (2.1) | 0 | 0 | 0 | |||
| RTx only | 1 (0.7) | 0 | 0 | 0 | |||
| Previous thoracic operation (n, %) | 2 (1.4) | 0 | 1.000 | 0 | 0 | NA | |
| Previous abdominal operation (n, %) | 5 (3.5) | 12 (17.1) | <0.001 | 5 (10.2) | 3 (6.1) | 0.414 | |
T-RAMIE, totally robot-assisted minimally invasive esophagectomy; H-RAMIE, hybrid robot-assisted minimally invasive esophagectomy; BMI, body mass index; ECOG PS, Eastern Cooperative Oncology Group performance status; COPD, chronic obstructive pulmonary disease; CCI, Charlson-Deyo comorbidity index; FEV1, forced expiratory volume in the first second; CCRT, concurrent chemoradiation therapy; CTx, chemotherapy; RTx, radiotherapy.