Risk Factors For Graft Occlusion Research Articles

The Results of Femorofemoral Bypass Using a Saphenous Vein Graft as an Alternative to PTFE Grafts.

This study aimed to report the results of femorofemoral bypass (FFB) using a great saphenous vein (GSV) graft as an alternative to polytetrafluoroethylene (PTFE) grafts. From January 2012 to December 2021, 168 patients who underwent FFB (PTFE, 143; GSV, 25) were included. The patients' demographic features and surgical intervention results were retrospectively reviewed. There were no intergroup differences in patients' demographic features. In GSV vs. PTFE grafts, the superficial femoral artery provided statistically significant inflow and outflow (P<0.001 for both), and redo bypass was more common (P=0.021). The mean follow-up duration was 24.7±2.3 months. The primary patency rates at 3 and 5 years were 84% and 74% for PTFE grafts and 82% and 70% for GSV grafts, respectively. There was no significant intergroup difference in primary patency (P=0.661) or clinically driven target lesion revascularization (CD-TLR)-free survival (P=0.758). Clinical characteristics, disease details, and procedures were analyzed as risk factors for graft occlusion. Multivariate analysis revealed that none of the factors was associated with an increased risk of FFB graft occlusion. FFB using PTFE or GSV grafts is a useful method with an approximately 70% 5-year primary patency rate. The GSV and PTFE grafts showed no difference in primary patency or CD-TLR-free survival during follow-up; however, FFB using GSV may be an option in selective situations.

A SYSTEMATIC REVIEW AND META-ANALYSIS OF 45 RANDOMIZED STUDIES USING PROTOCOL-DRIVEN ASSESSMENT OF SAPHENOUS VEIN GRAFT PATENCY

The saphenous vein (SV) is still the most commonly used conduit for coronary artery bypass grafting (CABG). Data on graft patency varies widely between studies. Here, we performed a systematic review and meta-analysis only of studies using protocol-driven angiogram and CT angiogram (CTA) to determine SV graft patency and identify risk factors for graft occlusion.

An evaluation of the long-term patency of the aortocoronary bypass graft anastomosed to a vascular prosthesis.

Although concomitant surgery for coronary artery disease (CAD) and thoracic aortic aneurysm is performed often, the long-term patency of the coronary artery bypass grafting (CABG) anastomosed to a vascular prosthesis has not been fully investigated. Here, we explored the long-term patency of the graft in comparison with the proximal anastomosis site on the native ascending aorta or vascular prosthesis. A total of 84 patients with concomitant CABG who underwent surgery for thoracic aortic aneurysm at 3 Osaka Cardiovascular Research Group institutes were retrospectively investigated for this study. The patency of 109 aortocoronary bypasses using saphenous vein grafts was evaluated with computed tomography angiography or coronary angiography, comparing the grafts anastomosed on the vascular prosthesis (group P, n = 75) to those anastomosed on the native ascending aorta (group N, n = 34). During 45.9 ± 39.7 months follow-up, significantly worse patency of the grafts in group P was revealed when compared with those in group N (100% vs 77.6% in 12 months, 100% vs 52.7% in 36 months and 100% vs 31.6% in 57 months, log rank P < 0.001). The poor patency of the grafts was confirmed in each target lesions (left anterior descending artery: P = 0.050, right coronary artery: P = 0.045, left circumflex artery: P = 0.051) and regardless of the severities of the target coronary vessels (severe stenosis: P = 0.013, mild-to-moderate stenosis: P = 0.029). Furthermore, an analysis of graft occlusion risk factors using the univariate Cox proportional hazards model revealed that the proximal anastomosis site on the vascular prosthesis was the sole risk factor for graft occlusion (P < 0.001). In the simultaneous surgery for CAD and thoracic aortic aneurysm, CABG design from vascular prosthesis to coronary artery should be avoided if possible, although further studies are warranted.

Prosthetic graft interposition of the brachiocephalic veins or superior vena cava combined with resection of malignant tumours: graft patency and risk factors for graft occlusion.

We aimed to assess graft patency in patients undergoing prosthetic graft interposition of the brachiocephalic veins (BCVs) or the superior vena cava (SVC) combined with resection of malignant tumours. A retrospective analysis was conducted on 16 patients who underwent prosthetic graft interposition of the BCVs or the SVC between 1998 and 2012. Among a total of 20 grafts in 16 patients (unilateral graft interposition in 12, bilateral graft interposition in 4), 8 grafts were occluded in 8 patients. Overall graft patency rate was 64.6%, 42.4% at the 2- and 5-year follow-up. Graft patency rate of the left BCV was significantly lower than that of the right BCV or the SVC (2-year patency, 38.1% vs. 81.8%, P=0.024). In univariate analysis, the superior anastomosis site [left BCV vs. right BCV; hazard ratio (HR) =2.312; 95% confidence interval (CI), 1.015-5.265; P=0.046], the inferior anastomosis site (right atrial appendage vs. SVC; HR =2.409; 95% CI, 1.124-5.161; P=0.024), and interruption of warfarin (HR =5.015; 95% CI, 1.106-22.734; P=0.037) were significant risk factors for graft occlusion. Graft occlusive symptoms were identified in 4 patients who underwent unilateral graft interposition. Prosthetic graft interposition between the left BCV and the right atrial appendage resulted in a significant rate of graft occlusion. Prosthetic graft interposition of the bilateral BCVs and long-term warfarin therapy may be necessary to prevent graft occlusive symptoms.

Balloon Angioplasty as the Primary Treatment for Failing Infrainguinal Vein Grafts

Background: We sought to evaluate the role of balloon angioplasty as the primary modality in the management of vein graft stenoses. Methods: Patients who underwent infrainguinal vein graft bypass from January 2002 to December 2007 were enrolled into a surveillance program. Grafts which developed critical stenoses were identified and underwent urgent angiography with a view to angioplasty of the stenotic lesion. Lesions which were deemed unsuitable for angioplasty underwent urgent surgical repair. Results: Four hundred and eleven grafts were followed up for a median of 19 months (range: 2–61). Ninety-six grafts (22.6%) developed critical stenosis. Twelve grafts occluded prior to repair and one was not intervened upon electively. Eight grafts underwent primary surgical repair. Seventy-six grafts underwent 99 endovascular procedures. Technical success was achieved in 60 grafts (78.9%). Of the grafts in which technical success had not been achieved, eight underwent repeat angioplasty and three were surgically repaired. Twenty-four grafts underwent repeat angioplasty for re-stenosis with a technical success rate of 71%. No difference was observed in graft patency (P = 0.08) or amputation rates (P = 0.32) between the grafts requiring intervention to maintain patency, and grafts which did not. Smoking [OR: 2.61 (95% CI: 1.51–4.53), (P = 0.006)], diabetes [OR: 2.55 (95% CI: 1.49–4.35), (P = 0.006)], renal failure [OR: 1.89 (95% CI: 1.19–3.38), (P = 0.040)] and recurrent stenosis [OR: 3.22 (95% CI: 1.63–4.69), (P < 0.001)] were risk factors for graft occlusion. Conclusions: Balloon angioplasty of failing infrainguinal vein bypass grafts is safe and can be performed with an acceptable medium term patency rate, albeit with a significant risk of re-stenosis which can be successfully treated in most patients using repeat endovascular intervention.

Balloon Angioplasty as the Primary Treatment for Failing Infra-inguinal Vein Grafts

Background We sought to evaluate the role of balloon angioplasty as the primary modality in the management of vein graft stenoses. Methods Patients who underwent infrainguinal vein graft bypass from January 2002 to December 2007 were enrolled into a surveillance program. Grafts which developed critical stenoses were identified and underwent urgent angiography with a view to angioplasty of the stenotic lesion. Lesions which were deemed unsuitable for angioplasty underwent urgent surgical repair. Results Four hundred and eleven grafts were followed up for a median of 19 months (range: 2–61). Ninety-six grafts (22.6%) developed critical stenosis. Twelve grafts occluded prior to repair and one was not intervened upon electively. Eight grafts underwent primary surgical repair. Seventy-six grafts underwent 99 endovascular procedures. Technical success was achieved in 60 grafts (78.9%). Of the grafts in which technical success had not been achieved, eight underwent repeat angioplasty and three were surgically repaired. Twenty-four grafts underwent repeat angioplasty for re-stenosis with a technical success rate of 71%. No difference was observed in graft patency ( P = 0.08) or amputation rates ( P = 0.32) between the grafts requiring intervention to maintain patency, and grafts which did not. Smoking [OR: 2.61 (95% CI: 1.51–4.53), ( P = 0.006)], diabetes [OR: 2.55 (95% CI: 1.49–4.35), ( P = 0.006)], renal failure [OR: 1.89 (95% CI: 1.19–3.38), ( P = 0.040)] and recurrent stenosis [OR: 3.22 (95% CI: 1.63–4.69), ( P < 0.001)] were risk factors for graft occlusion. Conclusions Balloon angioplasty of failing infrainguinal vein bypass grafts is safe and can be performed with an acceptable medium term patency rate, albeit with a significant risk of re-stenosis which can be successfully treated in most patients using repeat endovascular intervention.

The influence of hyperhomocysteinemia on graft patency after infrainguinal bypass surgery in the Dutch BOA Study

Objective: Hyperhomocysteinemia has been identified as a risk factor for (cardio)vascular disease. Whether hyperhomocysteinemia contributes to graft failure after peripheral bypass surgery remains unclear. The present study evaluated the influence of hyperhomocysteinemia on graft patency after infrainguinal bypass surgery. Design: The present study was designed as a nested case-control study. Method: In this study (nested in the Dutch Bypass Oral anticoagulants or Aspirin Study), 150 patients with graft occlusion were each matched with two randomly selected controls with patent grafts (N = 299) from the same trial. Venous blood samples were drawn from cases and controls, and total plasma homocysteine (tHcy) was determined. Mean serum homocysteine levels and the presence of hyperhomocysteinemia (>95th percentile in healthy individuals) were compared between cases and controls. Results: No significant differences were found between serum levels of homocysteine in patients with and without graft occlusion. The mean plasma homocysteine levels were 14.4 μmol/L and 14.9 μmol/L in the case and control groups, respectively. The resulting mean difference was −0.4 (95% confidence interval [CI], −1.8-0.9). The odds ratio of hyperhomocysteinemia was 0.81 (95% CI, 0.49-1.33). Adjustment for risk factors of graft occlusion did not change these results. Conclusions: Postoperative raised serum levels of homocysteine proved not to be a risk factor for graft occlusion after infrainguinal bypass grafting. (J Vasc Surg 2002;36:336-40.)

Worse clinical outcome but similar graft patency in women versus men one year after coronary artery bypass graft surgery owing to an excess of exposed risk factors in women

OBJECTIVESThis retrospective study sought to assess differences in graft patency and clinical outcome between women and men after coronary artery bypass graft surgery (CABG).BACKGROUNDA less favorable clinical outcome has been reported in women as compared with men. Its relation to graft patency has not been studied.METHODSWe analyzed one-year follow-up data of 912 patients (120 women) who entered a randomized clinical drug trial. All patients received vein grafts; in 494 patients (56 women) internal mammary artery (IMA) grafts were also used. Graft patency was assessed by coronary angiography at one year. Primary clinical end points were myocardial infarction, revascularization procedures and death; secondary clinical end points included recurrent angina, heart failure and arrhythmias.RESULTSOcclusion rates of vein grafts were 16.7% in women and 12.4% in men (odds ratio [OR] 1.62, 95% confidence interval [CI] 0.88 to 3.00, p = 0.12); occlusion rates of IMA grafts were 3.4% and 5.7% in women and men, respectively (OR 0.56, 95% CI 0.08 to 3.96, p = 0.56). Primary clinical end points were observed in 16.7% of women and 9.2% of men (OR 1.97, 95% CI 1.10 to 3.34, p = 0.022), and any clinical end point in 41.7% of women and 25.8% of men (OR 2.06, 95% CI 1.39 to 3.04, p = 0.0004). Myocardial infarction (15% vs. 7.6%, OR 2.15, 95% CI 1.24 to 3.75, p = 0.013) and recurrent angina (26.7% vs. 15.4%, OR 2.00, 95% CI 1.28 to 3.11, p = 0.004) occurred most frequently. Multivariate regression analysis did not identify gender as an independent risk factor for graft occlusion or the clinical end points. Graft occlusion was an independent predictor of the composite primary clinical end point (OR 2.75, 95% CI 1.59 to 4.75, p = 0.0003) and each of the secondary clinical end points. The observed differences were due to an imbalance of risk factors at baseline and to surgical and graft characteristics.CONCLUSIONSOne-year occlusion rates of vein and IMA grafts were comparable in women and men. Clinical outcome was related to graft patency and was less favorable in women owing to their uneven distribution of risk factors among both groups.

Analyses of coronary graft patency after aprotinin use: Results from the international multicenter aprotinin graft patency experience (IMAGE) trial

Objective: We examined the effects of aprotinin on graft patency, prevalence of myocardial infarction, and blood loss in patients undergoing primary coronary surgery with cardiopulmonary bypass. Methods: Patients from 13 international sites were randomized to receive intraoperative aprotinin (n = 436) or placebo (n = 434). Graft angiography was obtained a mean of 10.8 days after the operation. Electrocardiograms, cardiac enzymes, and blood loss and replacement were evaluated. Results: In 796 assessable patients, aprotinin reduced thoracic drainage volume by 43% ( P < .0001) and requirement for red blood cell administration by 49% ( P < .0001). Among 703 patients with assessable saphenous vein grafts, occlusions occurred in 15.4% of aprotinin-treated patients and 10.9% of patients receiving placebo ( P = .03). After we had adjusted for risk factors associated with vein graft occlusion, the aprotinin versus placebo risk ratio decreased from 1.7 to 1.05 (90% confidence interval, 0.6 to 1.8). These factors included female gender, lack of prior aspirin therapy, small and poor distal vessel quality, and possibly use of aprotinin-treated blood as excised vein perfusate. At United States sites, patients had characteristics more favorable for graft patency, and occlusions occurred in 9.4% of the aprotinin group and 9.5% of the placebo group ( P = .72). At Danish and Israeli sites, where patients had more adverse characteristics, occlusions occurred in 23.0% of aprotinin- and 12.4% of placebo-treated patients ( P = .01). Aprotinin did not affect the occurrence of myocardial infarction (aprotinin: 2.9%; placebo: 3.8%) or mortality (aprotinin: 1.4%; placebo: 1.6%). Conclusions: In this study, the probability of early vein graft occlusion was increased by aprotinin, but this outcome was promoted by multiple risk factors for graft occlusion. (J Thorac Cardiovasc Surg 1998;116:716-30)

Risk factors for graft occlusion after coronary artery bypass grafting.

A cohort of 610 well-characterized patients undergoing coronary artery bypass grafting were followed through the first postoperative year. Graft patency was angiographically assessed in 578 (94.8%) of the patients on average 12.1 (SD 1.5) months postoperatively and was related to characteristics of grafts and patients. For internal mammary artery grafts the incidence of graft occlusion was higher in women than in men and was inversely related to body surface area. In multivariate analysis the influence of gender was no longer significant when adjusted for body surface area. With vein grafts the incidence of occlusion was inversely related to body surface area and was positively associated with ejection fraction. Occlusion of vein grafts was less common in patients treated with beta-blockers pre- and peroperatively.

Fibrinolytic capacity after venous stasis in patients undergoing aorto‐coronary by‐pass surgery. Relation to shunt occlusion

In a prospective study 99 consecutive patients admitted for elective aorto‐coronary by‐pass surgery were subjected to estimation of their fibrinolytic capacity.Reevaluation after 16 months included shunt angiography and repeated testing of the fibrinolytic capacity.In the total material consisting of 244 grafts (2.7 per patient) 76 (31%) were occluded. In the subgroup of 24 patients with reduced fibrinolytic capacity, 25 (38%) of the 66 grafts were occluded as compared to 53 (30%) of the 178 grafts in patients with normal fibrinolytic capacity (p = 0.2). The number of grafts per patient and the values of the peroperatively measured blood flow in the grafts were similar in the 2 groups.Looking into the subgroup of grafts with “poor flow values” as measured peroperatively (≤ 35 ml/min), 14 (78%) of 18 grafts were occluded in patients with reduced fibrinolytic capacity, whereas 28 (53%) of 53 grafts were occluded in patients with normal fibrinolytic capacity (p = 0.06).In conclusion, the present study is thought to indicate that reduced fibrinolytic capacity might be an additional risk factor for graft occlusion in patients undergoing aorto‐coronary by‐pass surgery, particularly so in grafts where low blood flow values are obtained.