The impact of radiation dose exposure during endovascular aneurysm repair on patient safety.

OBJECTIVE: Endovascular aneurysm repair (EVAR) exposes patients to radiation during the procedure and in subsequent follow-up. The study goal was to calculate the radiation dose in our unit and compare it against other published data and national guidelines. METHODS: All EVAR procedures were identified from a prospectively maintained database. Radiation dose, screening time, and volume of intravenous contrast during the procedure were reviewed. Radiation exposure from subsequent computed tomography (CT) imaging was included in the overall exposure. Results are expressed as mean +/- standard deviation. RESULTS: From October 1998 to October 2008, 320 elective patients underwent EVAR. Mean screening time was 29.4 +/- 23.3 minutes, and the radiation dose was 11.7 +/- 7.1 mSv. The EVAR was an emergency in 64 patients. The mean screening time was 22.9 +/- 18.2 minutes, and the radiation dose was 13.4 +/- 8.6 mSv. During the first postoperative year, follow-up CT scans exposed the patients to 24.0 mSv, with 8.0 mSv in subsequent years. Abdominal radiographs added an additional 1.8 mSv each year. CONCLUSION: EVAR and the follow-up investigations involve substantial amounts of radiation, with well-recognized carcinogenic risks. Because patient safety is paramount, radiation exposure should be minimized. This may be possible by standardizing radiation exposure throughout the United Kingdom by implementing national guidelines and considering other imaging modalities for follow-up.

Common polymorphisms of Fibulin-5 and the risk of abdominal aortic aneurysm development.

Fibulin-5 is a crucial protein in the connective tissue structure of the aortic wall. The purpose of this study was to determine if genetic variation within the Fibulin-5 gene was associated with abdominal aortic aneurysms (AAA). AAA patients, with disease-free controls, were recruited and a past medical history questionnaire completed. Three single nucleotide polymorphisms (SNPs) in the FBLN5 gene (rs2498834, rs2430366 and rs2254320) were genotyped. The two cohorts were compared and haplotype analysis performed. A total of 230 AAA cases and 278 controls were successfully genotyped. The mean age was 71.9 years (+/- 6.8). No difference between cases and controls was found in the distribution of alleles of FBLN5 SNPs rs2498834 (p = 0.47), rs2430366 (p = 0.45) or rs2254320 (p = 0.46). Haplotype analysis did not reveal any significant difference. In conclusion, genetic variation within FBLN5 is unlikely to play any role in the development of AAA.

Collected world and single center experience with endovascular treatment of ruptured abdominal aortic aneurysms.

BACKGROUND: Case and single center reports have documented the feasibility and suggested the effectiveness of endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs), but the role and value of such treatment remain controversial. OBJECTIVE: To clarify these we examined a collected experience with use of EVAR for RAAA treatment from 49 centers. METHODS: Data were obtained by questionnaires from these centers, updated from 13 centers committed to EVAR treatment whenever possible and included treatment details from a single center and information on 1037 patients treated by EVAR and 763 patients treated by open repair (OR). RESULTS: Overall 30-day mortality after EVAR in 1037 patients was 21.2%. Centers performing EVAR for RAAAs whenever possible did so in 28% to 79% (mean 49.1%) of their patients, had a 30-day mortality of 19.7% (range: 0%-32%) for 680 EVAR patients and 36.3% (range: 8%-53%) for 763 OR patients (P < 0.0001). Supraceliac aortic balloon control was obtained in 19.1% +/- 12.0% (+/-SD) of 680 EVAR patients. Abdominal compartment syndrome was treated by some form of decompression in 12.2% +/- 8.3% (+/-SD) of these EVAR patients. CONCLUSION: These results indicate that EVAR has a lower procedural mortality at 30 days than OR in at least some patients and that EVAR is better than OR for treating RAAA patients provided they have favorable anatomy; adequate skills, facilities, and protocols are available; and optimal strategies, techniques, and adjuncts are employed.

The vascular and biochemical effects of cilostazol in patients with peripheral arterial disease.

OBJECTIVES: Cilostazol improves walking distance and quality of life in patients with peripheral arterial disease (PAD). This study assessed the vascular and biochemical effects of cilostazol therapy in PAD patients. METHODS: PAD patients were prospectively recruited to a randomized, double-blinded, placebo-controlled trial. Baseline clinical data were recorded. Clinical assessment included measurement of arterial compliance, transcutaneous oxygenation, ankle-brachial index (ABI), and treadmill walking distance. Blood analyses included a full blood panel, coagulation screen, urea and electrolytes, liver function tests, estimated glomerular filtration rate, and lipid profiles. Quality of life indices were recorded using validated generic and walking-specific questionnaires. All tests were performed at baseline, 6, and 24 weeks. RESULTS: Eighty patients (53 men) were recruited from December 2004 to January 2006. The cilostazol group had a significant reduction in the augmentation index compared with the placebo group at 6 weeks (19.7% vs 26.7%, P = .001) and at 24 weeks (19.7% vs 27.7%, P = .005). A paradoxic reduction in transcutaneous oxygenation levels was identified in the cilostazol group for the left foot at 6 weeks and for the right foot at both 6 and 24 weeks. The ABIs were not significantly different between treatment groups at baseline, 6 weeks, or 24 weeks for the left and right lower limbs. The mean percentage change in walking distance from baseline improved more markedly in the cilostazol compared with the placebo group for absolute claudication distance at 6 (78.6% vs 26.4%, P = .20) and 24 weeks (173.1% vs 92.1%, P = .27); however, these failed to reach significance. Significant improvements in lipid profiles were demonstrated with cilostazol therapy at 6 weeks (triglycerides, high-density lipoprotein [HDL]) and at 24 weeks (cholesterol, triglycerides, HDL, and low-density lipoprotein). The cilostazol treatment group demonstrated significant improvements in the Short Form-36 (physical functioning, physical component score), Walking Impairment (distance and speed), and Vascular Quality of Life (pain) indices at 6 and 24 weeks. Although cilostazol was associated with side effects in approximately one-third of patients, most settled within 6 weeks, facilitating the continuation of therapy in >89%. CONCLUSION: Cilostazol is a well-tolerated, safe, and efficacious treatment for PAD patients. It not only improves patients' symptomatology and quality of life but also appears to have beneficial effects on arterial compliance, possibly through its lipid-lowering property.

The effects of abdominal compartment hypertension after open and endovascular repair of a ruptured abdominal aortic aneurysm.

OBJECTIVE: This study assessed if emergency endovascular repair (eEVR) reduces the increase in intra-abdominal compartment pressure and host inflammatory response in patients with ruptured abdominal aortic aneurysm (AAA). METHODS: Thirty patients with ruptured AAA were prospectively recruited. Patients were offered eEVR or emergency conventional open repair (eOR) depending on anatomic suitability. Intra-abdominal pressure was measured postoperatively, at 2 and 6 hours, and then daily for 5 days. Organ dysfunction was assessed preoperatively by calculating the Hardman score. Multiple organ dysfunction syndrome, systemic inflammatory response syndrome, and lung injury scores were calculated regularly postoperatively. Hematologic analyses included serum urea and electrolytes, liver function indices, and C-reactive protein. Urine was analyzed for the albumin-creatinine ratio. RESULTS: Fourteen patients (12 men; mean age, 72.2 +/- 6.2 years) underwent eEVR, and 16 (14 men; mean age, 71.4 +/- 7.0 years) had eOR. Intra-abdominal pressure was significantly higher in the eOR cohort compared with the eEVR group. The eEVR patients had significantly less blood loss (P < .001) and transfused (P < .001) and total intraoperative intravenous fluid infusion (P = .001). The eOR group demonstrated a greater risk of organ dysfunction, with a higher systemic inflammatory response syndrome score at day 5 (P = .005) and higher lung injury scores at days 1 and 3 (P = .02 and P = .02) compared with eEVR. A significant correlation was observed between intra-abdominal pressure and the volume of blood lost and transfused, amount of fluid given, systemic inflammatory response syndrome score, multiple organ dysfunction score, lung injury score, and the length of stay in the intensive care unit and hospital. CONCLUSION: These results suggest that eEVR of ruptured AAA is less stressful and is associated with less intra-abdominal hypertension and host inflammatory response compared with eOR.

C-reactive protein (CRP) elevation in patients with abdominal aortic aneurysm is independent of the most important CRP genetic polymorphism.

OBJECTIVE: C-reactive protein (CRP) is a marker of cardiovascular disease. The objective was to determine if abdominal aortic aneurysm (AAA) and CRP serum concentration and its CRP gene are associated. METHODS AND RESULTS: AAA patients and AAA negative controls were recruited. CRP concentration was measured and the single nucleotide polymorphism (SNP), rs3091244, assessed. AAA cases were divided into those measuring 30-55 mm and >55 mm in diameter, to assess correlation of CRP with AAA size. A total of 248 (227 male) cases and 400 (388 male) controls were included. CRP concentration was higher in cases (385.0 microl/dL [310.4-442.8] vs 180.3 microl/dL [168.1-196.9]; P < .0001). It was higher in large aneurysms (685.7 microl/dL [511.8-1083.0] vs 291.0 microl/dL [223.6-349.6]; P < .0001), with significant correlation observed to size (r = 0.37, P < .0001). CC was the most common SNP genotype with no difference in distribution (P = .43) between cases and controls. No difference existed in CRP for each genotype in the overall cohort (P = .17), cases (P = .18) and controls (P = .19). CONCLUSION: The results demonstrate that CRP production may be related to the presence of AAA, especially in advanced disease. The serum concentration of CRP does not appear to be influenced by the functional SNP of the CRP gene, which also appears to have no association with AAA formation.

Bilateral popliteal artery occlusion in a competitive bike rider: case report and clinical review.

Since its first description in 1879, popliteal artery entrapment syndrome remains a debilitating condition, which frequently affects young active people. Increased awareness of popliteal artery entrapment syndrome combined with improvements in investigative modalities has resulted in a more frequent diagnosis of this eminently treatable condition. In this article, a rare case of bilateral popliteal artery entrapment syndrome in a physically active 33-year-old man precipitated by competitive Bicycle Moto-Cross riding is presented. A higher index of suspicion for popliteal artery entrapment syndrome is recommended as the underlying pathology in a young active person with symptoms of lower limb claudication. Popliteal artery entrapment syndrome should be investigated with thorough radiological assessment prior to any therapeutic intervention, which is often fraught with difficulty due to chronically diseased vasculature and inherent anatomical anomalies.

Effect of preoperative renal dysfunction on mortality and postoperative renal failure following endovascular abdominal aortic aneurysm repair.

This study was aimed to assess the effect of preoperative renal dysfunction on mortality and postoperative renal failure in patients undergoing elective endovascular repair of abdominal aortic aneurysm. A total of 155 patients with a mean age of 74.9 years (+/-6.4) were included. In all, 31 patients (20%) had a preoperative creatinine level of >1.5 mg/dL, whereas 66 patients (42.6%) had an estimated glomerular filtration rate of <60 mL/min. Perioperative mortality was 2.6% with no significant difference between those with and without abnormal renal indices. Long-term survival at 4 years was 30% in patients with creatinine >1.5 mg/dL compared to over 60% in those with normal creatinine (P < .02). The difference in long-term survival was not as significant in patients with normal or reduced glomerular filtration rate (P = .13). However, neither creatinine nor glomerular filtration rate were found to accurately predict survival even though both demonstrated strong predictivity for postoperative renal failure in patients undergoing elective endovascular repair of abdominal aortic aneurysm.

Prescribing practice of general practitioners in Northern Ireland for peripheral arterial disease.

Peripheral arterial disease is prevalent and reflects overall cardiovascular disease state. Best medical treatment is the cornerstone of management to reduce peripheral arterial disease symptoms and to minimize vascular morbidity and mortality. The aim of this study was to assess the prescription practice of general practitioners in Northern Ireland for patients with peripheral arterial disease. All general practitioners were from the Northern Ireland Professional Medical Directory, and a questionnaire was used to determine the prescribing patterns for peripheral arterial disease. In all, 468 general practitioners responded; 94% prescribed aspirin to nondiabetic patients, and 44.9% prescribed statin, with similar results for diabetic patients. Angiotensin-converting enzyme inhibitors, multivitamins, and beta-blockers were not often prescribed. Statin was prescribed to patients with diabetic peripheral arterial disease at a lower cholesterol concentration. In all, 52% would consider statin and fibrate together. Budgetary consideration influenced 6%. Northern Ireland general practitioners are reluctant to prescribe medication that is effective in the secondary prevention of vascular morbidity and mortality in high-risk patients.

Inflammatory infrarenal abdominal aortic aneurysm in a young woman.

Inflammatory abdominal aortic aneurysm is a rare cause of abdominal pain in young adults that may be difficult to diagnose in the Emergency Department. This case highlights the significance of this condition as a possible diagnosis in young patients presenting with abdominal symptoms. A 32-year old woman presented with lower abdominal and back pain. She had four previous visits to the Emergency Department and one hospital admission with similar symptoms and had been discharged without a definite diagnosis. Her vascular risk factors included hypercholesterolemia and smoking. A computed tomography (CT) scan showed a non-leaking infrarenal saccular abdominal aortic aneurysm and para-aortic lymphadenopathy. A transthoracic echocardiogram excluded endocarditis. There was no evidence of bacterial, viral, or fungal infection on blood and serum assays, and her autoimmune screen was negative. She underwent urgent open repair using a synthetic graft. The aneurysmal wall and para-aortic lymph node histology confirmed the diagnosis of inflammatory aneurysm with periaortitis. She remained asymptomatic at 8 months after surgery with no evidence of additional aneurysmal disease. Inflammatory abdominal aortic aneurysm is an unusual cause of abdominal pain in young adults. It is more likely in patients with persistent or recurrent abdominal symptoms.

Decreased antioxidant vitamin concentration may be a risk factor for recurrent carotid stenosis.

Carotid endarterectomy has been found to be associated with a transient increase in systemic oxidative stress, and this has been shown to be a predictor of restenosis. The aim of this study was to determine the incidence of early recurrent stenosis and investigate a possible role of oxidative stress in its development by measuring the concentration of antioxidant vitamins. Patients undergoing carotid endarterectomy between August 2001 and February 2003 were included in the study. A preoperative blood sample was analyzed for antioxidant vitamin concentrations. All patients were followed up by duplex scans 3 and 12 months postoperatively. Ninety-three patients (101 carotid endarterectomies) were recruited. Nine arteries had developed restenosis by 12 months. Those patients who developed recurrent stenosis had significantly lower vitamin C concentrations (19.10 +/- 3.69 vs 30.11 +/- 19.10, P = .02) than those who did not. This study suggests that low antioxidant vitamin levels may predispose to early restenosis after carotid endarterectomy.

Benefits of a supervised exercise program after lower limb bypass surgery.

This study evaluated the efficacy of an exercise program after arterial bypass surgery. Patients undergoing bypass surgery were randomized to a control group (group I), with standard preoperative and postoperative care, or the intervention group (group II) with a supervised exercise program of twice-weekly treadmill assessments from 4 to 10 weeks postoperatively. Ankle-brachial pressure indices and hemodynamic measurements were recorded before and after exercise. The mean increase of maximum walking distance was 3.8% in group I and 175.4% in group II (P = .001). There was a significant difference between group I and II in the mean ankle-brachial pressure indices increase at the second assessment (0.08 versus 0.23; P = .02). A supervised exercise program leads to better improvement after lower limb bypass surgery for ischemia, but the feasibility of a formal exercise program would be undermined by the reluctance of patients to participate, both in the short-term and long-term.

No difference in medium-term outcome between Zenith and Talent stent-grafts in endovascular aneurysm repair.

BACKGROUND: Many devices are available for endovascular aneurysm repair (EVAR). Our aim was to analyze morphological effects of the Zenith and Talent systems. METHODS: Patients included underwent EVAR from June 1999 to June 2005 using a Zenith or Talent stent-graft, with computed tomography follow-up. Aortic dimensions over time and clinical outcome were analyzed. RESULTS: Twenty-nine patients with Zenith stent-grafts and 33 with Talent devices were included. Mean preoperative age was similar (75.5+/-6.0 years vs 74.2+/-6.7 years; P=.29). Preoperative neck length was longer in the Zenith group (29.9+/-15.2 mm vs 25.5 +/- 10.8 mm; P=.10), and stent-graft oversizing was greater in the Talent patients (20.2%+/-7.9% vs 23.0% +/- 11.3%). There was proximal aortic dilatation and aneurysm sac shrinkage in each group. Complication rates were comparable, with 83% of both groups free from 10-mm migration. CONCLUSION: Although device designs differ, there is no difference in clinical outcome between Zenith and Talent stent-grafts. Migration rates were not influenced by suprarenal fixation.

Setting the standards for reporting ruptured abdominal aortic aneurysm.

INTRODUCTION: Reported mortality rates for endovascular repair (EVR) of ruptured abdominal aortic aneurysm (rAAA) vary from 0% to 50%. Selection bias, inaccurate reporting, and lack of uniform reporting standards are responsible for this significant discrepancy. MATERIAL AND METHODS: Existing literature about the classification/reporting systems of rAAA is reviewed. A standard way of reporting rAAA based on the physiological, radiological, and operative findings is proposed. CONCLUSION: The proposed system attempts to provide a universal language of communicating the severity of rupture, address the reporting bias, and allow comparing the outcomes of rAAA.

Evaluation of angiography as the sole imaging study for the proximal aortic neck prior to EVAR.

BACKGROUND: Angiographic assessment is an alternative to computerised tomography (CT) prior to endovascular aneurysm repair (EVAR). We evaluated angiography in aortic neck morphology assessment as an alternative investigation. METHODS: Patients admitted for elective or emergency EVAR were assessed by pre-operative CT and intra-operative angiography. The proximal and distal aortic neck diameters, and neck length were measured. Measurements were expressed as median (95% CI). RESULTS: 35 patients (20 male) were assessed from August 2003 to January 2005 for elective (26) and emergency (9) EVAR. In the overall group, the proximal neck diameter was 22.0mm (21.0-23.0) on CT, and 20.7 mm (19.3-22.3) on angiography. The distal neck diameter was 23.0mm (22.0-24.0) on CT, and 22.3mm (20.3-24.6) on angiography, while the neck length was only slightly greater on angiography [23.0mm (17.5-28.4)] relative to CT [23.0mm (20.0-28.0)]. The stent-grafts deployed were oversized by 26.8% (+/- 14.8%) relative to the CT measurements, and 33.7% (+/- 15.6%) relative to angiographic measurements. Good correlation was found for all three measurements between CT and angiography. CONCLUSIONS: Angiography alone is inadequate for endovascular aneurysm repair. Although it has timesaving potential, the accuracy achieved is not sufficient to use alone.

The influence of COX-2 single nucleotide polymorphisms on abdominal aortic aneurysm development and the associated inflammation.

INTRODUCTION: Cyclooxygenase (COX)-2 influences cardiovascular disease and serum concentration of high-sensitivity C-reactive protein (hsCRP). The study purpose was to determine the influence of single nucleotide polymorphisms (SNPs) of the COX-2 gene on abdominal aortic aneurysm (AAA) development and serum hsCRP concentrations. PATIENTS AND METHODS: Patients with AAA and disease-free controls were recruited. High-sensitivity C-reactive protein was measured by an enzyme-linked immunosorbent assay (ELISA) test. The distributions of COX-2 SNPs were investigated (rs20417 and rs4648307). The influence of the COX-2 SNPs on the hsCRP serum concentration was assessed. RESULTS: A total of 230 patients with AAA and 279 controls were included. No difference was found in the genotype distribution of the COX-2 SNPs rs20417 (P = .26) and rs4648307 (P = .90). They did not influence the hsCRP concentration (P = .24 and P = .61, respectively). Haplotype analysis of COX-2 SNPs revealed no difference. CONCLUSION: These COX-2 SNPs do not play any role in AAA development and do not influence serum hsCRP. These results differentiate AAA development from atherosclerotic diseases.

The role of smoking in abdominal aortic aneurysm development.

Abdominal aortic aneurysm is common. The aim of this study was to assess the effect of smoking on prevalence and management. Patients attending the vascular unit and appropriate controls were prospectively recruited. A smoking history revealed tobacco exposure in pack years. Serum cotinine was assessed biochemically. Independent risk factors were statistically determined. In all, 202 (186 men) patients were recruited, with 202 (197 men) controls. A total of 69 patients tested positive for cotinine, whereas 39 controls were positive (P = .001). Smoking and ischemic heart disease were significant predictors for aneurysm prevalence. Cardiac disease emerged as a more important predictor than smoking in symptomatic patients. In noncardiac patients, smoking and hypercholesterolemia were significant risk factors. Smoking is a significant predictor for aneurysm development. In high-risk patients, the cardiac disease process is the most important factor, with control of this imperative. However, in noncardiac patients, smoking cessation and lipid-lowering therapy are crucial.

Inferior vena cava thrombosis in young adults--a review of two cases.

We present two cases of clinically extensive bilateral DVTs associated with inferior vena caval thrombosis. Young patients presenting with symptoms of DVT should be investigated not only to establish any thrombophilic pre-disposition, but to ascertain the proximal extent of thrombus which may itself influence treatment.

Effects of antioxidants on endothelial function in human saphenous vein in an ex vivo model.

This ex vivo study is aimed at determining the beneficial effects of antioxidant agents on human saphenous vein endothelial function. Vein rings harvested during infrainguinal bypass surgery were assessed in an organ bath for endothelium-dependent relaxation, initially without and then with the addition of 10 microM manganese tetrakis benzoic acid porphyrin (MnTBAP), 0.01% N-acetylcysteine (NAC), 0.02% NAC, 10 microM vitamin C, and 100 microM vitamin C. Fifty-five vein rings from 22 patients were analyzed. MnTBAP improved the endothelium-dependent relaxation when compared with control (57.0% vs 37.8%, P < .01). Addition of 0.01% or 0.02% NAC did not improve the endothelium-dependent vasorelaxation (28.2% vs 18.6%, P = ns and 37.8% vs 29.8%, P = ns, respectively). Although 10-microM vitamin C failed to improve endothelial function (50.6% vs 37.2%, P = ns), 100-microM vitamin C significantly enhanced endothelium-dependent relaxation (66.5% vs 38.3%, P < .001). These results suggest that the addition of MnTBAP and high-dose vitamin C can improve the endothelial function of harvested saphenous vein segments in an ex vivo model.