Baseline characteristics of cases and controls
| Variable | Cases (n=35) | Controls (n=70) | Test value and significance of null hypothesis | Crude odds ratios with confidence intervals (1.96*SE) | |
|---|---|---|---|---|---|
| Sex(M/F) | 27/8 (77%/23%) | 53/17 (76%/24%) | χ2 = 0.26 | 1.08 (0.41, 2.83) | |
| p = 0.871 | |||||
| Age (years, mean ± SD) | 65.00 ± 7.92 | 63.79 ± 10.02 | T = 0.626 | 1.01 (0.97, 1.06) | |
| p = 0.533 | |||||
| Clinical stage of disease according to Rutherford | I | 0 0% | 7 10% | χ2 = 25.848 | 2.82 (1.77, 4.48) |
| II | 0 0% | 16 22% | p < 0.001* | ||
| III | 6 17% | 21 30% | |||
| IV | 11 31% | 13 19% | |||
| V | 15 43% | 13 19% | |||
| VI | 3 9% | 0 0% | |||
| Duration of smoking (years, mean ± SD) | 28.03 ± 16.08 | 26.51 ± 17.03 | U=1213,000 | 1.01 (0.98, 1.03) | |
| p = 0.934 | |||||
| Alcohol consumption | 8/27 (23%/77%) | 18/52 (26%/74%) | χ2 = 0.102 | 0.86 (0.33, 2.22) | |
| p = 0.749 | |||||
| Form of femoropopliteal bypass (below-knee vs above-knee) | 25/10 (71%,29%) | 22/48 (31%, 69%) | χ2 = 15.099 | 5.45 (2.24, 13.28) | |
| p < 0.001* | |||||
| Anticoagulant(AC) and Antiaggregant (AA) therapy | AC+AA 23 66% | AC+AA 34 49% | χ2 =4.001 | 0.58 (0.31, 1.11) | |
| AC 11 31% | AC 29 41% | p = 0.261 | |||
| AA 0 0% | AA 4 6% | ||||
| without | without | ||||
| AA/AC 3 3% | AA I AC 3 4% | ||||
| Type of heparin | SH 28 80% | S 54 77% | χ2 = 0.274 | 0.85 (0.42, 1.71) | |
| LMWH 5 14% | LMWH 10 14% | p = 0.872 | |||
| S+LMWH 2 6% | S+LMWH 6 9% | ||||
| Preoperative levels of haemoglobin | 128.91 ± 20.85 | 133.67 ± 19.98 | T = −1.134 | 0.99 (0.97, 1.01) | |
| p = 0.260 | |||||
| Preoperative levels of aPTT | 28.12 ± 5.11 | 27.92 ± 6.27 | U = 1157.500 | 1.01 (0.94, 1.08) | |
| p = 0.646 | |||||
| Preoperative levels of INR | 1.14 ± 0.30 | 1.08 ± 0.38 | U = 1067.000 | 1.57 (0.51, 4.89) | |
| p = 0.283 | |||||
| Preoperative levels of hematocrit | 38.57 ± 6.36 | 40.18 ± 5.67 | T = −1.323 | 0.95 (0.891, 1.023) | |
| p = 0.189 | |||||
| Aortoiliac stenosis | 6/29 (17%/83%) | 18/52 (26%/74%) | χ2 = 0.972 | 0.60 (0.21, 1.67) | |
| p = 0.324 | |||||
| Previous vascular intervention | 9/26 (26%/74%) | 13/57 (19%/81%) | χ2 = 0.719 | 1.52 (0.58, 4.00) | |
| p = 0.397 | |||||
| Angiotensin converting enzyme (ACE) inhibitors | 24/11 (69%/31%) | 50/19 (71%/29%) | χ2 = 0.677 | 0.80 (0.33, 1.94) | |
| p = 0.713 | |||||
| Beta blockers | 16/19 (46%/54%) | 28/42 (40%/60%) | χ2 = 0.313 | 1.26 (0.56, 2.86) | |
| p = 0.576 | |||||
| Diuretics | 11/24 (31%/69%) | 24/46 (34%/66%) | χ2 = 0.086 | 0.88 (0.37, 2.09) | |
| p = 0.770 | |||||
| Calcium channel blockers | 6/29 (17%/83%) | 17/53 (24%/76%) | χ2 = 0.696 | 0.64 (0.23, 1.82) | |
| p = 0.404 | |||||
| Metformin | 2/33 (6%/94%) | 14/56 (20%/80%) | χ2 = 3.687 | 0.24 (0.05, 1.13) | |
| p = 0.055 | |||||
| Insulin | 5/30 (14%/86%) | 9/61 (13%/87%) | χ2 = 0.041 | 1.13 (0.35, 3.67) | |
| p = 0.839 | |||||
| Type of graft (artificially vs venous) | 32/3 (91%/9%) | 61/9 (87%/13%) | χ2 = 0.423 | 1.57 (0.40, 6.22) | |
| p = 0.515 | |||||
| Finnvastic score | 5/30 (14%/86%) | 5/65 (7%/93%) | χ2 = 1.382 | 2.17 (0.58, 8.05) | |
| p = 0.295 | |||||
| Cardiovascular diseases | 20/15 | 26/44 | χ2 = 3.791 | 2.26 (0.98, 5.16) | |
| 57%/43% | 37%/63% | p = 0.052 | |||
| Chronic renal insufficiency | 5/30 | 4/66 | χ2 = 2.188 | 2.75 (0.69, 10.97) | |
| 14%/86% | 6%/94% | p = 0.156 | |||
| Peptic ulcer disease | 5/30 | 5/65 | χ2 = 1.382 | 2.17 (0.58, 8.05) | |
| 14%/86% | 7%/93% | p = 0.295 | |||
| Number of angiographically passable crural recipient arteries | 16/9/8 | 15/28/21 | χ2 = 6.359 | 1.75 (1.01, 3.06) | |
| 48,5%/27,3%/24,2% | 32,8%/43,8%/23,4% | p = 0.042* | |||
| 1/2/3 | |||||
| Diabetes | 11/24 | 23/47 | χ2 = 0.022 | 0.94(0.39, 2.24) | |
| 31%/69% | 33%/67% | p = 0.883 | |||
| Malignancy | 0/35 | 5/65 | χ2 = 2.625 | 0.00 | |
| 0%/100% | 7%/93% | p = 0.167 | |||
| Perioperative blood transfusion | 6/29 | 9/61 | χ2 = 0.350 | 1.40 (0.46, 4.31) | |
| 17%/83% | 13%/87% | p = 0.554 | |||
| Alpha blockers | 2/33 | 2/68 | χ2 = 0.520 | 2.06 (0.28, 15.28) | |
| 6%/94% | 3%/97% | p = 0.471 | |||
Crude and adjusted odds ratios of the risk factors for femoropopliteal bypass graft occlusions*
| Risk factors | Crude OR (95% CI) | Adjusted OR (95% CI) |
|---|---|---|
| Form of femoropopliteal bypass (below-knee vs above-knee) | 5.45(2.24, 13.28) | 115.34(4.02, 3306.55) |
| Type of graft (artificially vs venous) | 1.57(0.40, 6.22) | 81.62(1.03, 6486.32) |
| Cardiovascular diseases | 2.26(0.98, 5.16) | 55.64(2.63, 1176.94) |
| Previous vascular intervention | 1.52(0.58, 4.00) | 51.61(1.10, 2425.14) |
| Clinical stage of disease according to Rutherford | 2.82(1.77, 4.48) | 22.21(2.62, 188.39) |
| Preoperative levels of haemoglobin | 0.99(0.97, 1.01) | 1.33(1.01, 1.74) |
| Preoperative levels of hematocrit | 0.95(0.89, 1.02) | 0.34 (0.13, 0.98) |
Synergistic effects of risk factors for the femoropopliteal bypass graft occlusions
| Risk factors | Crude OR (95% CI) | Adjusted OR (95% CI) |
|---|---|---|
| Form of femoropopliteal bypass (below-knee vs above-knee) | 5.45(2.24, 13.28) | 115.34(4.02, 3306.55) |
| Type of graft (artificially vs venous) | 1.57(0.40, 6.22) | 81.62(1.03, 6486.32) |
| Cardiovascular diseases | 2.26(0.98, 5.16) | 55.64(2.63, 1176.94) |
| Previous vascular intervention | 1.52(0.58, 4.00) | 51.61(1.10, 2425.14) |
| Clinical stage of disease according to Rutherford | 2.82(1.77, 4.48) | 22.21(2.62,188.39) |
| Preoperative levels of haemoglobin | 0.99(0.97, 1.01) | 1.33(1.01, 1.74) |
| Preoperative levels of hematocrit | 0.95 (0.89, 1.02) | 0.34 (0.13, 0.98) |
| Form of femoropopliteal bypass(below-knee vs above-knee) by Type of graft (artificially vs venous) | 5.54(2.30,13.35) | 140.95(5.47, 3632.14)* |
| p=0.003 | ||
| Type of graft (artificially vs venous) by Previous vascular intervention | 1.50(0.52,4.35) | 75.96(1.14, 5060.94)* |
| p=0.043 | ||
| Cardiovascular diseases by Form of femoropopliteal bypass(below-knee vs above-knee) | 4.50(1.75,11.60) | 68.03(3.14, 1472.69)* |
| p=0.007 | ||
| Type of graft (artificially vs venous) by Cardiovascular diseases | 2.03(0.89,4.64) | 25.71(1.69, 391.30)* |
| p=0.019 | ||
| Previous vascular intervention by Form of femoropopliteal bypass(below-knee vs above-knee) | 2.70(0.76,9.53) | 4.22(0.20, 90.46) |
| p=0.357 | ||
| Type of graft (artificially vs venous) by Clinical stage of disease according to Rutherford | 1.86(1.39,2.61) | 2.83 (1.28, 6.24)* |
| p=0.010 | ||
| Clinical stage of disease according to Rutherford by Form of femoropopliteal bypass(below-knee vs above-knee) | 1.65(1.32,2.05) | 2.58(1.47, 4.51)* |
| p=0.001 | ||
| Preoperative levels of haemoglobin by Form of femoropopliteal bypass(below-knee vs above-knee) | 1.01(1.01,1.02) | 1.02(1.01,1.04) |
| p=0.008 | ||
| Preoperative levels of hematocrit by Form of femoropopliteal bypass(below-knee vs above-knee) | 1.04(1.02,1.06) | 1.06(1.02,1.12) |
| p=0.009 | ||
| Preoperative levels of haemoglobin by Preoperative levels of hematocrit | 1.00(1.00–1.00) | 1.00(0.99,1.00) |
| p=0.381 | ||