Table 2. Characteristics of Surgery According to Treatment Group After Time-Dependent Propensity Score Matching.
| Characteristic | Patients, No. (%) | P Value | |
|---|---|---|---|
| MILS (n = 104) | Open Surgery (n = 412) | ||
| Extent of liver resection | |||
| Major | 28 (26.9) | 111 (26.9) | >.99 |
| Minor | 76 (73.1) | 301 (73.1) | |
| Difficulty score, median (range) | 6 (2-10) | 7 (2-10) | .92 |
| Liver resection | |||
| Right hepatectomy | 16 (15.4) | 64 (15.5) | .57 |
| Left hepatectomy | 10 (9.6) | 40 (9.7) | |
| Right trisectionectomy | 2 (1.9) | 8 (1.9) | |
| Left trisectionectomy | 0 | 0 | |
| Left lateral sectionectomy | 11 (10.6) | 44 (10.7) | |
| Bisegmentectomy | 17 (16.3) | 68 (16.5) | |
| Segmentectomy | 18 (17.3) | 72 (17.5) | |
| Single wedge resection | 17 (16.3) | 68 (16.5) | |
| Multiple wedge resections | 9 (8.7) | 36 (8.7) | |
| Right posterior sectionectomy | 3 (2.9) | 12 (2.9) | |
| Right anterior sectionectomy | 1 (1.0) | 4 (1.0) | |
| Conversion | 16 (15.4) | NA | NA |
| Two-stage hepatectomy | 6 (5.8) | 34 (8.3) | .09 |
| Associated procedures | 27 (26.0) | 112 (27.2) | .49 |
Abbreviations: MILS, minimally invasive liver surgery; NA, not assessable.