TABLE 2.
Baseline Characteristics Development and Validation Cohort
| Development cohort (2014–2017); N = 1954; n (%) | Validation cohort (2018); N= 545; n (%) | |
|---|---|---|
| Patient demographics | ||
| Age (yr); median (IQR) | 65 (57–72) | 64 (57–72) |
| Sex | ||
| Female | 540 (27.6) | 154 (28.3) |
| Male | 1414 (72.4) | 391 (71.7) |
| BMI (kg/m2) | ||
| Underweight (<18.5) | 91 (4.7) | 30 (5.5) |
| Normal (18.5–24.9) | 579 (29.6) | 169 (31) |
| Overweight (25.0–29.9) | 738 (37.8) | 193 (35.4) |
| Obese (>30) | 380 (19.4) | 119 (21.8) |
| Missing | 166 (8.5) | 34 (6.2) |
| ASA classification | ||
| ASA-I | 302 (15.5) | 80 (14.7) |
| ASA-II | 1098 (56.2) | 290 (53.2) |
| ASA-III/IV | 508 (25.9) | 162 (29.7) |
| Missing | 46 (2.4) | 13 (2.4) |
| Tumor characteristics | ||
| Clinical T-classification | ||
| T0 | 6 (0.3) | 4 (0.6) |
| T1 | 73 (3.7) | 10 (1.8) |
| T2 | 390 (20) | 117 (21.6) |
| T3 | 1206 (61.7) | 340 (62.4) |
| T4 | 190 (9.7) | 57 (10.5) |
| Missing | 89 (4.6) | 17 (3.1) |
| Clinical N-classification | ||
| N0 | 716 (36.6) | 218 (40) |
| N1 | 590 (30.2) | 182 (33.4) |
| N2 | 393 (20.1) | 110 (20.2) |
| N+ | 125 (6.4) | 23 (5.1) |
| Missing | 130 (6.7) | 12 (2.2) |
| Clinical M-disease | ||
| M0 | 1536 (78.6) | 428 (78.5) |
| M1 | 150 (7.7) | 43 (7.9) |
| Missing | 268 (13.7) | 74 (13.6) |
| Neoadjuvant therapy | ||
| None | 839 (42.9) | 241 (44.2) |
| Radiotherapy only | 238 (12.2) | 57 (10.5) |
| Chemotherapy | 41 (2.1) | 7 (1.3) |
| Chemoradiation | 836 (42.8) | 240 (44) |
| Tumor distance from the anorectal junction (mm); median (IQR) | 60 (32–90) | 60 (30–82) |
| Surgical characteristics | ||
| Abdominal approach | ||
| Laparoscopic | 1181 (60.4) | 357 (65.5) |
| Robot-assisted | 179 (9.2) | 58 (10.6) |
| Laparotomy | 593 (30.3) | 130 (23.9) |
| Missing | 1 (0.05) | — |
| TaTME | ||
| No | 1599 (81.8) | 433 (79.4) |
| Yes | 355 (18.2) | 111 (20.4) |
| Missing | — | 1 (0.2) |
| Specification approach | ||
| Open (TATA) | 82 (23.1) | 13 (11.7) |
| Transanal platform | 243 (68.5) | 90 (81.1) |
| Missing | 30 (8.4) | 8 (7.2) |
| Configuration anastomosis | ||
| End-to-end | 1184 (60.6) | 382 (70.1) |
| Side-to-end | 604 (30.9) | 138 (25.3) |
| Other* | 81 (4.1) | 10 (1.8) |
| Missing | 85 (4.4) | 15 (2.8) |
| Multivisceral resection | ||
| No | 1781 (91.1) | 494 (90.6) |
| Yes | 127 (6.5) | 41 (7.5) |
| Missing | 46 (2.4) | 10 (1.9) |
| Splenic flexure mobilization | ||
| No | 630 (32.2) | 183 (33.6) |
| Yes | 1014 (51.9) | 294 (53.9) |
| Missing | 310 (15.9) | 68 (12.5) |
| Defunctioning stoma created at index surgery | ||
| No | 656 (33.6) | 212 (38.9) |
| Yes | 1298 (66.4) | 333 (61.1) |
| Diagnostic characteristics | ||
| Clinical setting diagnosis AL | ||
| Surgical ward | 1324 (67.8) | 387 (71.0) |
| ICU/HC | 84 (4.3) | 24 (4.4) |
| ED | 198 (10.1) | 51 (9.4) |
| Out-patient clinic | 346 (17.7) | 81 (14.9) |
| Missing | 2 (0.1) | 1 (0.2) |
| Postoperative day of AL diagnosis; median (IQR) | 8 (5–18) | 7 (4–15) |
| Leakage characteristics | ||
| Leakage location | ||
| Circular | 1090 (55.8) | 337 (61.8) |
| Side-to-end | 183 (9.3) | 47 (8.6) |
| Missing | 681 (34.9) | 161 (29.6) |
| Anastomotic defect circumference | ||
| 0%–25% | 433 (39.7) | 139 (41.3) |
| 25%–50% | 230 (21.1) | 79 (23.4) |
| 50%–100% | 142 (13.0) | 55 (16.3) |
| Missing | 285 (26.2) | 64 (19) |
| Ischemia bowel wall | ||
| No | 1406 (72.0) | 376 (69.0) |
| Yes | 197 (10.1) | 64 (11.7) |
| Missing | 351 (17.9) | 105 (19.3) |
| Retraction afferent colon | ||
| No | 1426 (73.0) | 402 (73.8) |
| Yes | 76 (3.9) | 23 (4.2) |
| Missing | 452 (23.1) | 123 (22.6) |
| Fistula(s) | ||
| No | 1721 (88.1) | 473 (86.8) |
| Yes | 130 (6.7) | 47 (8.6) |
| Missing | 103 (5.2) | 25 (4.6) |
| Abdominal contamination | ||
| No | 1160 (59.4) | 294 (53.9) |
| Yes | 623 (31.9) | 200 (36.7) |
| Missing | 171 (8.7) | 51 (9.4) |
| Reactivation leakage | ||
| No | 1253 (64.1) | 354 (64.9) |
| Yes | 130 (6.7) | 31 (5.7) |
| Missing | 571 (29.2) | 160 (29.4) |
| Mortality | ||
| Mortality within 1 yr after index surgery | ||
| No | 1738 (88.9) | 485 (89.0) |
| Yes | 103 (5.3) | 27 (4.9) |
| Missing | 113 (5.8) | 33 (6.1) |
| Outcome | ||
| Stoma-free survival | ||
| No | 891 (45.6) | 252 (46.2) |
| Yes | 880 (45.0) | 238 (43.7) |
| Missing | 183 (9.4) | 55 (10.1) |
*
Other = colon pouch, coloplasty, ileal pouch-anal anastomosis.
BMI indicates body mass index; ED, emergency department; HC, high-dependency care; ICU, intensive care unit; TaTME, transanal total mesorectal excision; TATA, Transanal Abdominal Transanal Resection.