TABLE 1.
Demographic and clinicopathologic factors of the study population
| Variable | All patients (N = 877) | IMA ligation (N = 755), 86% | SRA ligation (N = 122), 14% | p |
|---|---|---|---|---|
| Age at diagnosis, median (IQR), y | 59 (52–67) | 59 (52–67) | 61 (51–68) | 0.2 |
| Sex, n (%) | ||||
| Men | 541 (62) | 454 (60) | 87 (71) | 0.02* |
| Women | 336 (38) | 301 (40) | 35 (29) | |
| Race, n (%) | ||||
| White | 682 (90) | 682 (90) | 98 (81) | <0.01* |
| Black | 59 (8) | 59 (8) | 15 (12) | |
| Other | 13 (2) | 13 (2) | 8 (7) | |
| Diabetes, n (%) | ||||
| No | 732 (84) | 623 (84) | 109 (90) | 0.17 |
| Yes | 135 (16) | 123 (16) | 12 (10) | |
| Smoking history, n (%) | ||||
| No | 644 (74) | 553 (74) | 91 (75) | 0.87 |
| Yes | 228 (26) | 198 (26) | 30 (25) | |
| Neoadjuvant therapy, n (%) | ||||
| No | 202 (23) | 171 (23) | 31 (25) | 0.59 |
| Yes | 673 (77) | 582 (77) | 91 (75) | |
| Functional status, n (%) | ||||
| Independent | 811 (98) | 697 (98) | 114 (98) | 0.88 |
| Partially dependent | 19 (2) | 17 (2) | 2 (2) | |
| ASA class, n (%) | ||||
| I | 6 (<1) | 5 (1) | 1 (1) | 0.14 |
| II | 371 (45) | 323 (45) | 48 (41) | |
| III | 439 (53) | 377 (53) | 62 (54) | |
| IV | 13 (2) | 8 (1) | 5 (4) | |
| Operation type, n (%) | ||||
| LAR | 620 (71) | 541 (72) | 79 (65) | 0.13 |
| APR | 257 (29) | 214 (28) | 43 (35) | |
| Approach, n (%) | ||||
| Open | 294 (34) | 223 (30) | 71 (58) | <0.01* |
| Minimally invasive | 582 (66) | 531 (70) | 51 (42) | |
| Small bowel resection(s), n (%) | ||||
| No | 605 (98) | 516 (99) | 89 (97) | 0.46 |
| Yes | 11 (2) | 8 (1) | 3 (3) | |
| Splenic flexure mobilization, n (%) | ||||
| No | 193 (24) | 170 (24) | 12 (21) | 0.61 |
| Yes | 628 (76) | 524 (76) | 86 (79) | |
| Lymph nodes retrieved, median (IQR) | 15 (12–19) | 15 (12–19) | 15 (13–20) | 0.38 |
| Lymph harvest, n (%) | ||||
| <12 lymph nodes | 190 (22) | 174 (23) | 16 (13) | 0.02* |
| ≥12 lymph nodes | 685 (78) | 580 (77) | 105 (87) | |
| Level of tumor from sphincters, mean, median (IQR), cm | 2.0, 1 (0–3) | 2.1, 1 (0–3) | 1.9, 1 (0–4) | 0.89 |
| Level of anastomosis from anal verge, mean, median (IQR), cm | 4.4, 4 (3–6) | 4.3, 4 (3–6) | 4.6, 5 (3–6) | 0.45 |
| Tumor differentiation, n (%) | ||||
| Well | 33 (5) | 30 (5) | 3 (3) | 0.08 |
| Moderate | 591 (86) | 498 (85) | 93 (94) | |
| Poor | 56 (8) | 53 (9) | 3 (3) | |
| Undifferentiated | 8 (1) | 8 (1) | 0 (0) | |
| Pathologic T stage (AJCC eighth edition), n (%) | ||||
| T0 | 110 (13) | 99 (13) | 11 (9) | <0.02* |
| Tis | 4 (<1) | 4 (<1) | 0 (0) | |
| T1 | 85 (10) | 71 (10) | 14 (12) | |
| T2 | 274 (31) | 227 (30) | 47 (39) | |
| T3 | 343 (39) | 308 (41) | 35 (29) | |
| T4a | 14 (2) | 11 (2) | 3 (2) | |
| T4b | 42 (5) | 31 (4) | 11 (9) | |
| Pathologic N stage (AJCC eighth edition), n (%) | ||||
| N0 | 592 (68) | 524 (70) | 68 (56) | 0.12 |
| N1a | 111 (13) | 93 (12) | 18 (15) | |
| N1b | 61 (7) | 50 (7) | 11 (9) | |
| N1c | 37 (4) | 29 (4) | 8 (7) | |
| N2a | 39 (4) | 31 (4) | 8 (7) | |
| N2b | 34 (4) | 27 (3) | 7 (6) | |
| Pathologic stage (AJCC eighth edition), n (%) | ||||
| 0 | 101 (12) | 91 (12) | 10 (9) | <0.01* |
| I | 281 (33) | 241 (33) | 40 (34) | |
| II | 206 (24) | 189 (26) | 17 (14) | |
| III | 269 (31) | 218 (30) | 51 (43) | |
| Final margin status, n (%) | ||||
| R0 | 833 (95) | 717 (95) | 116 (95) | 1.00 |
| R1 | 44 (5) | 38 (5) | 6 (5) | |
| Any complication, n (%) | ||||
| No | 403 (49) | 349 (49) | 54 (49) | 1.00 |
| Yes | 421 (51) | 364 (51) | 57 (51) | |
| Anastomotic leak, n (%) | ||||
| No | 393 (91) | 306 (91) | 87 (92) | |
| Yes | 38 (9) | 30 (9) | 8 (8) | 1.00 |
| Follow-up, median (IQR), mo | 31 (13–55) | 30 (13–55) | 36 (18–51) | 0.05* |
IQR = interquartile range; LAR = low anterior resection; APR = abdominoperineal resection; IMA = inferior mesenteric artery; SRA = superior rectal artery; AJCC = American Joint Committee on Cancer.
*
P value is significant.