Table 2. Comparative Analysis of Surgical Procedures and Outcomes in the Conventional Nipple-Sparing Mastectomy (C-NSM) and Minimal Access Nipple-Sparing Mastectomy (M-NSM) Groups.
| Variable | No. (%) | P value | |
|---|---|---|---|
| C-NSM (n = 1356) | M-NSM (n = 227) | ||
| Risk-reducing surgery | |||
| No | 1348 (99.41) | 226 (99.56) | >.99 |
| Yes | 8 (0.59) | 1 (0.44) | |
| Surgical extent | |||
| Unilateral | 1228 (90.56) | 180 (79.3) | <.001 |
| Bilateral | 128 (9.44) | 47 (20.7) | |
| Arm position | |||
| Raising arm | 17 (1.25) | 113 (49.78) | <.001 |
| Laying down | 129 (9.51) | 34 (14.98) | |
| 90° Extension | 894 (65.93) | 76 (33.48) | |
| Unknown | 316 (23.3) | 4 (1.76) | |
| Sentinel lymph node biopsy | |||
| No | 89 (6.56) | 6 (2.64) | .01 |
| Yes | 1267 (93.44) | 221 (97.36) | |
| Axillary lymph node dissection | |||
| No | 1135 (83.7) | 199 (87.67) | .07 |
| Yes | 221 (16.3) | 28 (12.33) | |
| Gas or gasless technique | |||
| Gasless | NA | 78 (34.36) | |
| Gas | NA | 149 (65.64) | |
| Incision location | |||
| Upper outer radial | 468 (34.51) | 6 (2.64) | <.001 |
| Inframammary | 332 (24.48) | 10 (4.41) | |
| Periareolar and extension | 153 (11.28) | 1 (0.44) | |
| Elliptical | 131 (9.66) | 0 | |
| Periareolar only | 16 (1.18) | 0 | |
| Horizontal | 28 (2.06) | 0 | |
| Mid or anterior axillary | 5 (0.37) | 177 (77.97) | |
| Inferior radial | 2 (0.15) | 0 | |
| Axillary | 0 | 12 (5.29) | |
| Other | 210 (15.49) | 18 (11.45) | |
| Initial incision size, mean (SD), cm | NA | 45.33 (11.49) | <.001 |
| Final incision size, mean (SD), cm | NA | 48.61 (11.89) | <.001 |
| Subcutaneous flap dissecting method | |||
| Hydrodissection | 21 (1.55) | 7 (3.08) | <.001 |
| Electrocauterization | 697 (51.4) | 33 (14.54) | |
| Both | 212 (15.63) | 187 (82.38) | |
| Unknown | 426 (31.42) | NA | |
| Time for mastectomy, mean (SD), min | 116.01 (47.21) | 146.94 (47.09) | <.001 |
| Specimen weight, mean (SD), g | 361.71 (197.53) | 347.88 (156.77) | .26 |
| Reconstruction method | |||
| Tissue expander | 338 (24.93) | 38 (16.74) | <.001 |
| Direct to implant | 682 (50.29) | 167 (73.57) | |
| TRAM/DIEP flap | 183 (13.5) | 14 (6.17) | |
| LD flap | 110 (8.11) | 4 (1.76) | |
| Other | 43 (3.17) | 4 (1.76) | |
| Using energy device | |||
| No | 441 (32.52) | 13 (5.73) | <.001 |
| Yes | 915 (67.48) | 214 (95.96) | |
| Using acellular dermal matrix | |||
| No | 382 (28.17) | 12 (5.29) | <.001 |
| Yes | 959 (70.72) | 215 (94.71) | |
| Unknown | 15 (11.06) | NA | |
| Implant volume, mean (SD), mL3 | 287.99 (189.36) | 339.95 (114.75) | <.001 |
| Amount of intraoperative bleeding, mean (SD), mL | 170.55 (195.72) | 136.24 (178.17) | .10 |
| Total amount of drainage, mean (SD), mL | 959.33 (657.59) | 1333.28 (859.29) | <.001 |
| Duration of drainage tube placement, mean (SD), d | 12.61 (4.11) | 16.88 (9.84) | <.001 |
Abbreviations: DIEP, deep inferior epigastric artery perforator; LD, latissimus dorsi myocutaneous; NA, not applicable; TRAM, transverse rectus abdominis musculocutaneous flap.