Retrospective Study
Copyright
©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Surg Proced. Jul 28, 2016; 6(2): 19-29
Published online Jul 28, 2016. doi: 10.5412/wjsp.v6.i2.19
Table 1 Baseline demographic and clinical characteristics
Characteristic Total n = 4063 Neoadjuvant patients n = 236 (5.81%) Surgery-only patients n = 3827 (94.19%) P -value1 Age (yr), median (IQR) 68 (61-75) 66 (55-72) 69 (61-75) < 0.0012 Male (%) 2003 (49.30) 125 (52.97) 1878 (49.07) 0.246 Race (%) White 3019 (74.30) 189 (80.08) 2830 (73.95) 0.173 Black 222 (5.46) 12 (5.08) 210 (5.49) Latino(a) 432 (10.63) 17 (7.20) 415 (10.84) Other or unknown 390 (9.60) 18 (7.63) 372 (9.72) ASA classification (%) 1-2 no-mild disturbance 769 (18.97) 38 (16.24) 731 (19.14) 0.523 3 serious disturbance 2888 (71.24) 171 (73.08) 2717 (71.13) 4-5 life threatening/moribund 397 (9.79) 25 (10.68) 372 (9.74) Functional status Independent 3985 (98.08) 229 (97.03) 3756 (98.14) 0.227 Partially/totally dependent 78 (1.92) 7 (2.97) 71 (1.86) Obese, BMI ≥ 30 (%) 1155 (28.65) 58 (24.79) 1097 (28.88) 0.178 Diabetes (%) 598 (14.72) 27 (11.44) 571 (14.92) 0.143 Current smoker (%) 1448 (35.64) 114 (48.31) 1334 (34.86) < 0.0012 Alcohol consumption (%) 221 (5.44) 15 (6.36) 206 (5.38) 0.522 Dyspnea (%) 1106 (27.22) 57 (24.15) 1049 (27.41) 0.275 History of COPD (%) 1082 (26.63) 54 (22.88) 1028 (26.86) 0.179 History of heart disease (%) 42 (1.03) 3 (1.27) 39 (1.02) 0.734 Hypertension (%) 2375 (58.45) 111 (47.03) 2264 (59.16) < 0.0012 Previous cardiac surgery (%) 308 (7.58) 11 (4.66) 297 (7.76) 0.081 Weight loss (%) 152 (3.74) 16 (6.78) 136 (3.55) 0.0112 Steroid use (%) 161 (3.96) 22 (9.32) 139 (3.63) < 0.0012 Year of operation (%) 2005-2008 834 (20.53) 53 (22.46) 781 (20.41) 0.662 2009-2010 1794 (44.15) 105 (44.49) 1689 (44.13) 2011-2012 1435 (35.32) 78 (33.05) 1357 (35.46) Preoperative WBC (%) Normal (4.5-11.0 × 109 /L) 3364 (85.88) 174 (74.36) 3190 (86.61) < 0.0012 Abnormal (< 4.5 or > 11.0 × 109 /L) 553 (14.12) 60 (25.64) 493 (13.39) Preoperative hematocrit (%) Normal (≥ 36) 3147 (80.53) 110 (47.01) 3037 (82.66) < 0.0012 Abnormal (< 36) 761 (19.47) 124 (52.99) 637 (17.34) Surgery type (%) VATS 1203 (29.61) 34 (14.41) 1169 (30.55) < 0.0012 Open 2860 (70.39) 202 (85.59) 2658 (69.45)
Table 2 Unadjusted intraoperative and postoperative complications
Characteristic Total n = 4063 Neoadjuvant patients n = 236 (5.81%) Surgery-only patients n = 3827 (94.19%) P -value1 30-d mortality (%) 107 (2.63) 19 (8.05) 88 (2.30) < 0.0012 Overall morbidity (%) 646 (15.90) 63 (26.69) 583 (15.23) < 0.0012 Wound infection 4 (0.10) 0 (0.00) 4 (0.10) 0.787 Pneumonia 5 (0.73) 0 (0.00) 5 (0.77) 0.774 Urinary tract infection 1 (0.15) 0 (0.00) 1 (0.16) 0.956 Return to OR 201 (4.95) 22 (9.32) 179 (4.68) < 0.0012 Venous thromboembolism 80 (1.97) 7 (2.97) 73 (1.91) 0.256 Cardiac complication 60 (1.48) 10 (4.24) 50 (1.31) < 0.0012 Shock/sepsis 107 (2.63) 11 (4.66) 96 (2.51) 0.0452 Unplanned intubation 207 (5.09) 27 (11.44) 180 (4.70) < 0.0012 Bleeding transfusion 178 (4.38) 28 (11.86) 150 (3.92) <0.0012 Renal complication 22 (0.54) 0 (0.00) 22 (0.57) 0.636 On ventilator > 48 h 3 (0.07) 1 (0.42) 2 (0.05) 0.164 Organ space SSI 44 (1.08) 1 (0.42) 43 (1.12) 0.516 Serious morbidity (%) 469 (11.54) 44 (18.64) 425 (11.11) < 0.0012 Length of stay (d), median (IQR) 6 (4-9) 6 (4-9) 6 (4-8) 0.915 Prolonged length of stay (%) 816 (20.08) 46 (19.49) 770 (20.12) 0.815 Operative time (min), median (IQR) 161 (123-216) 160 (121-214) 192 (147-250) < 0.0012 Prolonged operative time (%) 1006 (24.76) 91 (38.56) 915 (23.91) < 0.0012
Table 3 Intraoperative/postoperative outcomes overall and among propensity-score matched cohorts (results represent odds ratios unless otherwise indicated)
Characteristic Unadjusted (95%CI) P -value1 Risk-adjusted (95%CI) P -value1 Propensity-score matched cohort3 (95%CI) P -value1 30-d mortality (%) 3.72 (2.22-6.22) < 0.0011 2.70 (1.54-4.72) 0.0011 1.63 (0.77-3.45) 0.197 Overall morbidity (%) 2.02 (1.50-2.74) < 0.0011 1.53 (1.12-2.11) 0.0101 1.68 (1.08-2.62) 0.0211 Return to OR 2.09 (1.32-3.33) 0.0011 1.77 (1.08-2.90) 0.0231 3.37 (1.41-8.04) 0.0061 Cardiac complication 3.34 (1.67-6.70) 0.0011 3.11 (1.47-6.57) 0.0031 2.57 (0.79-8.30) 0.116 Shock/sepsis 1.90 (1.00-3.60) 0.0491 1.53 (0.78-3.02) 0.217 3.80 (1.05-13.80) 0.0431 Unplanned intubation 2.62 (1.71-4.02) < 0.0011 2.03 (1.28-3.22) 0.0021 1.66 (0.88-3.14) 0.116 Bleeding transfusion 3.30 (3.15-5.06) < 0.0011 1.72 (1.08-2.73) 0.0231 2.31 (1.17-4.58) 0.0161 Serious morbidity (%) 1.83 (1.30-2.58) 0.0011 1.55 (1.08-2.23) 0.0181 1.70 (1.02-2.85) 0.0421 Length of stay (d)2 Predicted difference in means -0.02 (-0.38 to 0.35) 0.927 -0.93 (-1.32 to -0.55) < 0.0011 -1.02 (-1.54 to -0.50) < 0.0011 Prolonged length of stay (%) 0.96 (0.87-1.34) 0.815 0.67 (0.47-0.96) 0.0301 0.63 (0.41-0.97) 0.0371 Operative time (min)2 Predicted difference in means 30.5 (28.8-32.1) < 0.0011 26.4 (24.7-28.1) < 0.0011 29.0 (26.5-31.6) < 0.0011 Prolonged operative time (%) 2.00 (1.52-2.62) < 0.0011 1.81 (1.36-2.41) < 0.0011 1.73 (1.17-2.57) 0.0061
Table 4 Baseline demographic and clinical characteristics among the unmatched population cohort
Characteristic Surgery only n = 3593 (94.21%) Chemotherapy n = 64 (1.68%) Radiotherapy n = 100 (2.62%) Chemo and radio n = 57 (1.49%) P -value1 Age (yr), median (IQR) 69 (61-75) 66 (62-73) 66 (53-69) 62 (52-70) < 0.0012 Male (%) 1774 (49.59) 35 (54.69) 45 (45.45) 28 (49.12) 0.662 Race (%) Non-Hispanic White 2678 (78.58) 48 (78.69) 83 (86.46) 46 (85.19) 0.508 Non-Hispanic Black 194 (5.69) 3 (4.92) 5 (5.21) 4 (7.41) Hispanic 393 (11.53) 7 (11.48) 4 (4.17) 3 (5.56) Other or unknown 143 (4.20) 3 (4.92) 4 (4.17) 1 (1.85) ASA classification (%) 1-2 no-mild disturbance 2573 (71.61) 51 (79.69) 71 (71.00) 41 (71.93) 0.445 3 serious disturbance 665 (18.51) 10 (15.63) 19 (19.00) 7 (12.28) 4-5 life threatening/moribund 355 (9.88) 3 (4.69) 10 (10.00) 9 (15.79) Functional status Independent 3528 (98.19) 61 (95.31) 98 (98.00) 56 (98.25) 0.413 Partially/totally dependent 65 (1.81) 3 (4.69) 2 (2.00) 1 (1.75) Obese, BMI ≥ 30 (%) 1093 (30.42) 20 (31.25) 22 (22.00) 14 (24.56) 0.245 Diabetes (%) 546 (15.20) 11 (17.19) 9 (9.00) 5 (8.77) 0.178 Current smoker (%) 1223 (34.04) 29 (45.31) 48 (48.00) 30 (52.63) < 0.0012 Alcohol consumption (%) 193 (5.37) 5 (7.81) 6 (6.00) 4 (7.02) 0.785 Dyspnea (%) 975 (27.14) 14 (21.88) 24 (24.00) 16 (28.07) 0.711 History of COPD (%) 962 (26.77) 19 (29.69) 21 (21.00) 11 (19.30) 0.317 History of heart disease (%) 38 (1.06) 0 (0.00) 3 (3.00) 0 (0.00) 0.186 Hypertension (%) 2134 (59.39) 31 (48.44) 48 (48.00) 25 (43.86) 0.0042 Previous cardiac surgery (%) 280 (7.79) 2 (3.13) 6 (6.00) 3 (5.26) 0.422 Weight loss (%) 115 (3.20) 0 (0.00) 8 (8.00) 5 (8.77) 0.0032 Steroid use (%) 132 (3.67) 6 (9.38) 10 (10.00) 3 (5.26) 0.0012 Year of operation (%) 2005-2008 728 (20.26) 6 (9.38) 34 (34.00) 9 (15.79) < 0.0012 2009-2010 1577 (43.89) 21 (32.81) 61 (61.00) 18 (31.58) 2011-2012 1288 (35.85) 37 (57.81) 5 (5.00) 30 (52.63) Preoperative WBC (%) Normal (4.5-11.0 × 109 /L) 2988 (83.16) 54 (84.38) 73 (73.00) 38 (66.67) < 0.0012 Abnormal (< 4.5 or > 11.0 × 109 /L) 468 (13.03) 10 (15.63) 27 (27.00) 17 (29.82) Preoperative hematocrit (%) Normal (≥ 36) 2860 (79.60) 32 (50.00) 52 (52.00) 23 (40.35) < 0.0012 Abnormal (< 36) 588 (16.37) 32 (50.00) 48 (48.00) 32 (56.14) Preoperative albumin (%) Normal (≥ 3.5 g/dL) 3345 (93.10) 58 (90.63) 82 (82.00) 55 (96.49) < 0.0012 Abnormal (< 3.5 g/dL) 248 (6.90) 6 (9.38) 18 (18.00) 2 (3.51) Managing specialty (%) Thoracic 2243 (62.43) 48 (75.00) 48 (48.00) 40 (70.18) 0.0082 General 991 (27.58) 11 (17.19) 42 (42.00) 11 (19.30) Other specialty 359 (9.99) 5 (7.81) 10 (10.00) 6 (10.53) Surgery type (%) Open 2545 (70.83) 51 (79.69) 86 (86.00) 53 (92.28) < 0.0012 VATS 1048 (29.17) 13 (20.31) 14 (14.00) 4 (7.02)
Table 5 Unadjusted intraoperative/postoperative outcomes among the unmatched population cohort
Characteristic Surgery only n = 3593 (94.21%) Chemotherapy n = 64 (1.68%) Radiotherapy n = 100 (2.62%) Chemo and radio n = 57 (1.49%) P -value1 30-d mortality (%) 83 (2.31) 3 (4.69) 9 (9.00) 5 (8.77) < 0.0012 Overall morbidity (%) 415 (11.55) 13 (20.31) 21 (21.00) 17 (29.82) < 0.0012 Wound infection 3 (0.08) 0 (0.00) 0 (0.00) 0 (0.00) -- Pneumonia 4 (0.11) 0 (0.00) 0 (0.00) 0 (0.00) -- Urinary tract infection 1 (0.03) 0 (0.00) 0 (0.00) 0 (0.00) -- Return to OR 170 (4.73) 7 (10.94) 10 (10.00) 4 (7.02) 0.0122 Venous thromboembolism 70 (1.95) 0 (0.00) 2 (2.00) 3 (5.26) 0.212 Cardiac complication 47 (1.31) 2 (3.13) 2 (2.00) 4 (7.02) 0.0022 Shock/sepsis 92 (2.62) 2 (3.13) 5 (5.00) 2 (3.51) 0.513 Unplanned intubation 169 (4.70) 5 (7.81) 12 (12.00) 7 (12.28) < 0.0012 Bleeding transfusion 133 (3.70) 8 (12.50) 7 (7.00) 10 (17.54) < 0.0012 Renal complication 22 (0.61) 0 (0.00) 0 (0.00) 0 (0.00) -- On ventilator > 48 h 2 (0.06) 1 (1.56) 0 (0.00) 0 (0.00) -- Organ space SSI 38 (1.06) 0 (0.00) 1 (1.00) 0 (0.00) -- Serious morbidity (%) 372 (10.35) 12 (18.75) 19 (19.00) 10 (17.54) 0.0022 Length of stay (d), median (IQR) 6 (4-8) 5 (4-7) 6 (5-9) 5 (4-8) 0.134 Prolonged length of stay (%) 899 (25.02) 10 (15.63) 28 (28.00) 13 (22.81) 0.306 Operative time (min), median (IQR) 160 (121-214) 187 (140-246) 202 (151-253) 182 (142-249) < 0.0012 Prolonged operative time (%) 858 (23.44) 23 (35.94) 41 (41.00) 20 (35.09) < 0.0012
Table 6 Intraoperative/postoperative outcomes among propensity-score matched cohorts3 relative to the surgery only group (results represent odds ratios unless otherwise indicated)
Characteristic Surgery only varied size with cohort Chemotherapy n = 64 matched patients Radiotherapy n = 100 matched patients Chemo and radio n = 57 matched patients 30-d mortality (%) 1.00 (reference) 0.74 (0.16-3.43) 1.24 (0.73-2.13) 1.38 (0.79-2.43) Overall morbidity (%) 1.00 (reference) 1.10 (0.46-2.65) 1.14 (0.80-1.62) 1.38 (1.01-1.89)1 Serious morbidity (%) 1.00 (reference) 1.25 (0.50-3.13) 1.00 (0.70-1.42) 1.00 (0.72-1.38) Length of stay (d)2 Predicted mean difference 0.00 (reference) -1.43 (-2.19 to -0.68)1 0.34 (0.08-0.60)1 -0.04 (-0.28-0.21) Prolonged length of stay (%) 1.00 (reference) 0.56 (0.21-1.46) 0.95 (0.68-1.31) 0.78 (0.57-1.06) Operative time (min)2 Predicted mean difference 0.00 (reference) 13.8 (10.7-17.0)1 19.9 (18.7-21.1)1 9.49 (8.41-10.6)1 Prolonged operative time (%) 1.00 (reference) 2.20 (1.00-4.87)1 1.56 (1.15-2.11)1 1.03 (0.79-1.34)
Table 7 Rates of intraoperative and postoperative complications in cohorts matched for each outcome
Characteristic Neoadjuvant patients n = 234 (50.00%)3 Surgery-only patients n = 234 (50.00%)3 Odds ratio (95%CI) P -value1 30-d mortality (%) 19 (8.12) 12 (5.13) 1.63 (0.77-3.45) 0.197 Overall morbidity (%) 63 (26.92) 42 (17.95) 1.68 (1.08-2.62) 0.0211 Return to OR 22 (9.40) 7 (2.99) 3.37 (1.41-8.04) 0.0061 Cardiac complication 10 (4.27) 4 (1.71) 2.57 (0.79-8.30) 0.116 Shock/sepsis 11 (4.70) 3 (1.28) 3.80 (1.05-13.80) 0.0431 Unplanned intubation 27 (11.54) 17 (7.26) 1.66 (0.88-3.14) 0.116 Bleeding transfusion 28 (11.97) 13 (5.56) 2.31 (1.17-4.58) 0.0161 Serious morbidity (%) 44 (18.80) 28 (11.97) 1.70 (1.02-2.85) 0.0421 Length of stay (d)2 Predicted difference in means -- -- -1.02 (-1.54 to -0.50) < 0.0011 Prolonged length of stay (%) 44 (18.80) 63 (26.92) 0.63 (0.41-0.97) 0.0371 Operative time (min)2 Predicted difference in means -- -- 29.0 (26.5-31.6) < 0.0011 Prolonged operative time (%) 90 (38.46) 62 (26.50) 1.73 (1.17-2.57) 0.0061