Detection of Chlamydia pneumoniae but not cytomegalovirus in occluded saphenous vein coronary artery bypass grafts.
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BACKGROUND: A causal relation between atherosclerosis and chronic infection with Chlamydia pneumoniae and/or cytomegalovirus (CMV) has been suggested. Whether the unresolved problem of venous coronary artery bypass graft occlusion is related to infection with C pneumoniae and/or CMV has not been addressed. METHODS AND RESUTLS: Thirty-eight occluded coronary artery vein grafts and 20 native saphenous veins were examined. Detection of C pneumoniae DNA was performed by use of nested polymerase chain reaction (PCR). Homogenisates from the specimen were cultured for identification of viable C pneumoniae. Both conventional PCR and quantitative PCR for detection of CMV DNA were applied. Differential pathological changes (degree of inflammation, smooth muscle cell proliferation [MIB-1]) were determined and correlated to the detection of both microorganisms. C pneumoniae DNA could be detected in 25% of occluded vein grafts. Viable C pneumoniae was recovered from 16% of occluded vein grafts. Except for 1 native saphenous vein, all control vessels were negative for both C pneumoniae detection and culture. All pathological and control specimens were negative for CMV DNA detection. Pathological changes did not correlate with C pneumoniae detection. CONCLUSIONS: Occluded aorto-coronary venous grafts harbor C pneumoniae but not CMV. The detection of C pneumoniae in occluded vein grafts warrants further investigation. (+info)
Right atrial bypass grafting for central venous obstruction associated with dialysis access: another treatment option.
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PURPOSE: Central venous obstruction is a common problem in patients with chronic renal failure who undergo maintenance hemodialysis. We studied the use of right atrial bypass grafting in nine cases of central venous obstruction associated with upper extremity venous hypertension. To better understand the options for managing this condition, we discuss the roles of surgery and percutaneous transluminal angioplasty with stent placement. METHODS: All patients had previously undergone placement of bilateral temporary subclavian vein dialysis catheters. Severe arm swelling, graft thrombosis, or graft malfunction developed because of central venous stenosis or obstruction in the absence of alternative access sites. A large-diameter (10 to 16 mm) externally reinforced polytetrafluoroethylene (GoreTex) graft was used to bypass the obstructed vein and was anastomosed to the right atrial appendage. This technique was used to bypass six lesions in the subclavian vein, two lesions at the innominate vein/superior vena caval junction, and one lesion in the distal axillary vein. RESULTS: All patients except one had significant resolution of symptoms without operative mortality. Bypass grafts remained patent, allowing the arteriovenous grafts to provide functional access for 1.5 to 52 months (mean, 15.4 months) after surgery. CONCLUSION: Because no mortality directly resulted from the procedure and the morbidity rate was acceptable, this bypass grafting technique was adequate in maintaining the dialysis access needed by these patients. Because of the magnitude of the procedure, we recommend it only for the occasional patient in whom all other access sites are exhausted and in whom percutaneous dilation and/or stenting has failed. (+info)
Factors influencing the development of vein-graft stenosis and their significance for clinical management.
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OBJECTIVES: To assess the influence of clinical and graft factors on the development of stenotic lesions. In addition the implications of any significant correlation for duplex surveillance schedules or surgical bypass techniques was examined. PATIENTS AND METHODS: In a prospective three centre study, preoperative and peroperative data on 300 infrainguinal autologous vein grafts was analysed. All grafts were monitored by a strict duplex surveillance program and all received an angiogram in the first postoperative year. A revision was only performed if there was evidence of a stenosis of 70% diameter reduction or greater on the angiogram. RESULTS: The minimum graft diameter was the only factor correlated significantly with the development of a significant graft stenosis (PSV-ratio > or = 2.5) during follow-up (p = 0.002). Factors that correlated with the development of event-causing graft stenosis, associated with revision or occlusion, were minimal graft diameter (p = 0.001), the use of a venovenous anastomosis (p = 0.005) and length of the graft (p = 0.025). Multivariate regression analysis revealed that the minimal graft diameter was the only independent factor that significantly correlated with an event-causing graft stenosis (p = 0.009). The stenosis-free rates for grafts with a minimal diameter < 3.5 mm, between 3.5-4.5 and > or = 4.5 mm were 40%, 58% and 75%, respectively (p = < 0.05). Composite vein and arm-vein grafts with minimal diameters > or = 3.5 mm were compared with grafts which consisted of a single uninterrupted greater saphenous vein with a minimal diameter of < 3.5 mm. One-year secondary patency rates in these categories were of 94% and 76%, respectively (p = 0.03). CONCLUSIONS: A minimal graft diameter < 3.5 mm was the only factor that significantly correlated with the development of a graft-stenosis. However, veins with larger diameters may still develop stenotic lesions. Composite vein and arm-vein grafts should be used rather than uninterrupted small caliber saphenous veins. (+info)
Frame dislocation of body middle rings in endovascular stent tube grafts.
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OBJECTIVES: To understand the cause, and propose a mechanism for frame dislocation in endovascular grafts. MATERIALS AND METHODS: Five tube grafts were explanted due to secondary distal leakage 15-21 months after operation. One bifurcated graft was removed during emergency operation after aortic rupture caused by secondary leakage. A second bifurcated graft was harvested from a patient with thrombotic occlusion of one limb, who died after transurethral prostatic resection. The inside of the grafts were examined endoscopically. The stent was inspected after removal of the fabric, broken ligatures were counted and examined by scanning electron microscopy. The fabric strength was tested by probe puncture. RESULTS: We found 17-44% of the stent ligatures of the body middle rings to be loose. The knots were intact. Degradation of the polyester textile was not observed. CONCLUSIONS: Continuous movements in the grafted aorta and blood pressure impose permanent stress to the stent frame and the polyester fabric resulting in morphological changes in the body middle ring of grafts. The clinical implications of the suture breakages are unknown although they may be related to distal secondary leakage in tube grafts. (+info)
Relationship of femorodistal bypass patency to clinical outcome. Iloprost Bypass International Study Group.
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OBJECTIVE: To investigate the relationship between bypass patency, limb survival and clinical symptoms after femorodistal bypass procedures. DESIGN: Multicentre, prospectively planned 12-month postoperative follow-up. PATIENTS AND METHODS: Five hundred and seventeen patients undergoing femorodistal bypass surgery for severe ischaemia. Clinical symptoms, bypass patency were recorded at regular intervals up to 12 months postoperatively. RESULTS: Complete follow-up data was obtained on 498 patients (96%). Fifty-six (17%) of the 341 patients with patent bypasses had either rest pain or ulcers or had undergone major amputation at 12 months. Of the 167 patients with an occluded bypass, 22 patients (13%) had improved clinical symptoms and a total of 59 patients (35%) had avoided major amputation at 12 months. The clinical outcome for patients classified preoperatively as Fontaine stage IV was significantly worse than for those in stage III preoperatively despite similar bypass patency rates. CONCLUSIONS: There is a fair correlation between technical and clinical outcome after femorodistal bypass surgery at 12 months, but there are significant numbers of patients with occluded bypasses who have a good clinical outcome and of patients with patent bypasses who have a poor clinical outcome. The reporting of symptoms in addition to bypass patency would aid the interpretation of surgical results. (+info)
Lipoprotein(a) and coronary thrombosis and restenosis after stent placement.
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OBJECTIVES: The objective of this prospective study was to evaluate the relation between high lipoprotein(a) levels and thrombotic and restenotic events after coronary stent implantation. BACKGROUND: Lipoprotein(a) may promote atherogenesis, coronary thrombosis and restenosis after balloon angioplasty, but the clinical significance remains unclear. METHODS: The study included 2,223 consecutive patients with successful coronary stent placement. According to the serum level of lipoprotein(a), patients were divided in two groups: 457 patients of the highest quintile formed the high lipoprotein(a) group, and 1,766 patients of the lower four quintiles formed the low lipoprotein(a) group. Primary end points were the incidence of angiographic restenosis at six months and the event-free survival at one year. Secondary end point was the incidence of angiographic stent occlusion. RESULTS: Early stent occlusion occurred in four of the 457 patients (0.9%) with high and 37 of the 1,766 patients (2.1%) with low lipoprotein(a) levels, odds ratio of 0.41 (95% confidence interval, 0.15 to 1.16). Angiographic restenosis occurred in 173 of the 523 lesions (33.2%) in the high lipoprotein(a) group and 636 of the 1,943 lesions (32.7%) in the low lipoprotein(a) group, odds ratio of 1.02 (0.83 to 1.25). The probability of event-free survival was 73.0% in the high lipoprotein(a) group and 74.8% in the low lipoprotein(a) group (p = 0.45). On the basis of the findings in the low lipoprotein(a) group, the power of this study to detect a 25% increase in the incidence of restenosis and adverse events in the group with elevated lipoprotein(a) was 90% and 75%, respectively. CONCLUSIONS: Elevated lipoprotein(a) levels did not influence the one-year clinical and angiographic outcome after stent placement. Thrombotic events and measures of restenosis were not adversely affected by the presence of high lipoprotein(a) levels. (+info)
Prospective study of health related quality of life before and after coronary artery bypass grafting: outcome at five years.
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OBJECTIVE: To determine the long term health related quality of life of coronary artery bypass graft patients, to look at changes between one and five years after surgery, and to examine the ability of preoperative variables to predict longer term outcome. DESIGN: Nottingham health profile (NHP) was used to assess patients at five years compared to results obtained at one year. PATIENTS: 100 male patients aged < 60 years at time of surgery; 77 had three vessel disease and 84 received three or more saphenous vein grafts. RESULTS: In comparing the five year results with those at one year, lower mean scores, indicating slight improvements, were seen in the NHP dimensions of pain, sleep, social isolation, and emotional reactions, whereas signs of deterioration were noted in the physical mobility and energy scores. Chest pain was experienced by 34 of 84 patients at five years compared with 17 of 89 patients at one year. The proportion of patients who were unrestricted in their activities ranged from 61-70% at five years compared with 82-88% at one year. Absence of dyspnoea before surgery, indicating relatively good left ventricular function, was a predictor of good outcome at both one and five years. CONCLUSIONS: Evidence of deterioration in physical function is compatible with expected decline in graft patency; specific rather than generic measures were most sensitive to this change. (+info)
Coronary artery stenting in unstable angina pectoris: a comparison with stable angina pectoris.
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OBJECTIVE: To compare early complication rates in unselected cases of coronary artery stenting in patients with stable v unstable angina. SETTING: Tertiary referral centre. PATIENTS: 390 patients with stable angina pectoris (SAP) and 306 with unstable angina (UAP). Patients treated for acute myocardial infarction (primary angioplasty) or cardiogenic shock were excluded. INTERVENTIONS: 268 coronary stents were attempted in 211 patients (30.3%). Stents used included AVE (63%), Freedom (14%), NIR (7%), Palmaz-Schatz (5%), JO (5%), and Multilink (4%). Intravascular ultrasound was not used in any of the cases. All stented patients were treated with ticlopidine and aspirin together with periprocedural unfractionated heparin. RESULTS: 123 stents were successfully deployed in 99 SAP patients v 132 stents in 103 UAP patients. Failed deployment occurred with nine stents in SAP patients, v four in UAP patients (NS). Stent thrombosis occurred in four SAP patients and 11 UAP patients. Multivariate analysis showed no relation between stent thrombosis and clinical presentation (SAP v UAP), age, sex, target vessel, stent length, or make of stent. Stent thrombosis was associated with small vessel size (p < 0.001) and bailout stenting (p = 0.01) compared with elective stenting and stenting for suboptimal PTCA, with strong trends toward smaller stent diameter (p = 0.052) and number of stents deployed (p = 0.06). Most stent thromboses occurred in vessels < 3 mm diameter. CONCLUSIONS: Coronary artery stenting in unstable angina is safe in vessels >/= 3 mm diameter, with comparable initial success and stent thrombosis rates to stenting in stable angina. (+info)