Table 4. Pathological findings of the patients in the Xi® and Si® groups Pathology.
| Variables | All patients (n=286) | Conventional (n=169) | Reduced port (n=117) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Xi® (n=107) | Si® (n=179) | P-value | Xi® (n=61) | Si® (n=108) | P-value | Xi® (n=46) | Si® (n=71) | P-value | ||
| EGC | 73 (68.2) | 121 (67.5) | 0.828 | 39 (63.9) | 67 (62.0) | 0.806 | 34 (73.9) | 54 (76.1) | 0.774 | |
| AGC | 34 (31.7) | 58 (32.4) | - | 22 (36.1) | 41 (38.0) | - | 12 (26.1) | 17 (23.9) | - | |
| Histological type | 0.973 | 0.346 | 0.817 | |||||||
| Well differentiated | 6 (5.6) | 11 (6.1) | 2 (3.3) | 7 (6.5) | 4 (8.7) | 4 (5.6) | ||||
| Moderately differentiated | 34 (31.8) | 54 (30.2) | 22 (36.1) | 39 (36.1) | 12 (26.1) | 15 (21.1) | ||||
| Poorly differentiated | 38 (35.5) | 65 (36.3) | 19 (31.1) | 35 (32.4) | 19 (41.3) | 30 (42.3) | ||||
| Mucinous | 2 (1.9) | 2 (1.1) | 2 (3.3) | 0 (0.0) | 0 (0.0) | 2 (2.8) | ||||
| Signet ring carcinoma | 24 (22.4) | 39 (21.8) | 15 (24.6) | 22 (20.4) | 9 (19.6) | 17 (23.9) | ||||
| Others | 3 (2.8) | 8 (4.5) | 1 (1.6) | 5 (4.6) | 2 (4.3) | 3 (4.2) | ||||
| Tumor size (mm) | 32.7±24.4 | 32.5±20.3 | 0.946 | 33.8±21.5 | 32.6±21.8 | 0.743 | 31.3±27.9 | 32.3±17.9 | 0.804 | |
| Depth of invasion | 0.075 | 0.085 | 0.781 | |||||||
| Mucosa | 45 (42.1) | 58 (32.4) | 23 (37.7) | 29 (26.9) | 22 (47.8) | 29 (41.4) | ||||
| Submucosa | 28 (26.2) | 63 (35.2) | 16 (26.2) | 38 (35.2) | 12 (26.0) | 25 (34.3) | ||||
| Proper muscle | 11 (10.4) | 15 (8.4) | 7 (11.5) | 8 (7.4) | 4 (8.7) | 7 (10.0) | ||||
| Subserosal | 7 (6.6) | 26 (14.5) | 4 (6.6) | 21 (19.4) | 3 (6.5) | 5 (7.1) | ||||
| Serosal exposure | 15 (14.2) | 16 (8.9) | 10 (16.4) | 11 (10.2) | 5 (10.8) | 5 (7.1) | ||||
| Adjacent organ invasion* | 1 (0.9) | 0 (0.0) | 1 (1.6) | 0 (0.0) | - | - | ||||
| No residual cancer† | 0 (0.0) | 1 (0.6) | 0 (0.0) | 1 (0.9) | - | - | ||||
| N stage | 0.721 | 0.415 | 0.449 | |||||||
| N0 | 79 (73.8) | 127 (70.9) | 46 (75.4) | 71 (65.7) | 33 (71.7) | 56 (78.8) | ||||
| N1 | 21 (19.6) | 38 (21.2) | 11 (18) | 24 (22.2) | 10 (21.7) | 14 (19.7) | ||||
| N2 | 4 (3.7) | 11 (6.1) | 2 (3.3) | 10 (9.3) | 2 (4.3) | 1 (1.4) | ||||
| N3 | 3 (2.8) | 3 (1.7) | 2 (3.3) | 3 (2.8) | 1 (2.2) | 0 (0.0) | ||||
| Lymphovascular invasion | 0.688 | 0.668 | 0.199 | |||||||
| No | 75 (70.1) | 130 (72.3) | 43 (70.5) | 73 (67.3) | 32 (69.6) | 57 (80.0) | ||||
| Yes | 32 (29.9) | 49 (27.7) | 18 (29.5) | 35 (32.7) | 14 (30.4) | 14 (20.0) | ||||
| Perineural invasion | 0.542 | 0.668 | 0.431 | |||||||
| No | 84 (78.5) | 144 (80.4) | 46 (75.4) | 85 (78.7) | 38 (82.6) | 59 (82.9) | ||||
| Yes | 23 (21.4) | 35 (19.6) | 15 (24.6) | 23 (21.3) | 8 (17.4) | 12 (17.1) | ||||
| Retrieved LNs | 58.0±23.2 | 57.4±24.2 | 0.827 | 60.6±24.2 | 59.5±26.6 | 0.802 | 54.7±21.45 | 54.1±19.5 | 0.882 | |
| Metastatic LNs | 1.5±4.1 | 1.8±5.9 | 0.728 | 1.6±4.6 | 2.4±7.5 | 0.446 | 3.43±0.51 | 1.7±0.21 | 0.159 | |
Data are shown as mean±standard deviation or number (%).
EGC = early gastric cancer; AGC = advanced gastric cancer; Xi = the da Vinci Xi® system; Si = the da Vinci Si® system; LN = lymph node.
*Invasion to distal pancreas; †Post chemotherapy after cycles of docetaxel, oxaliplatin, and S-1 regimen.