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.

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.

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.

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.

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 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.

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.

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.

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.

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.

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.

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.

Advantages and pitfalls of abdominal aortic aneurysm screening in high-risk patients.

Screening for abdominal aortic aneurysm (AAA) has been suggested for older men. Our aim was to determine the effect of participant selection on prevalence and treatment suitability. Men aged 65 to 75 years attending cardiology clinics composed the high-risk group; the control group was from the community. AAA screening was performed, with follow-up or surgery arranged. Four hundred eight of 651 (62.7%) high-risk men and 109 of 908 (45.0%; p< .0001) men attended from the community. In the high-risk patients, 40 AAAs were diagnosed, with a mean diameter of 41.4 mm (+/-10.4 mm). In the control group, 22 new AAAs were found, with an average size of 40.9 mm (+/-10.4 mm). Higher polypharmacy existed in the high-risk group (4.6+/-2.2 vs 2.3+/-2.0; p< .0001). More aneurysm patients were on dual-antiplatelet therapy (32.5% vs 15.4%; p= .048) compared with the overall high-risk group. In this group, three underwent surgery; one was anatomically unsuitable for endovascular repair and medically unfit for open repair. Two in the control group had surgery. A higher prevalence of AAA is encountered in high-risk men. Most aneurysms are small; however, a significant proportion of the aneurysms detected were of a size that would warrant repair. The decision to perform surgical repair is likely to be influenced by the comorbid medical conditions, which placed the patients in the high-risk category.

Risk factors for abdominal aortic aneurysm and the influence of social deprivation.

INTRODUCTION: the objective of this abdominal aortic aneurysm (AAA) screening study was to determine attendance and disease prevalence patterns in Northern Ireland and the role of deprivation and other risk factors. PATIENTS AND METHODS: patients from primary care practices from Belfast, Lisburn, and Saintfield were screened. Past medical history and deprivation details were determined. RESULTS: 2264 men from Belfast, 1104 men in Lisburn, and 284 in Saintfield were invited to attend. Overall, 1659 (45.3%) men attended, with 40.6% from Belfast, 55.0% from Lisburn, and 45.8% from Saintfield (P < .0001). Ninety-two (5.5%) new AAAs were diagnosed, with 6.5%, 3.8%, and 6.2% in the 3 areas (P = .055). As deprivation decreased, attendance increased and prevalence decreased. Smoking, peripheral arterial disease, number of medications prescribed, and geographical origin were independent risk factors for AAAs. CONCLUSION: aneurysm prevalence is influenced by geographical origin and deprivation, which should, therefore, be important factors in health care planning and screening provision.

The effects of cilostazol on peripheral neuropathy in diabetic patients with peripheral arterial disease.

BACKGROUND: Evidence from diabetic animal models suggests that cilostazol, a cyclic AMP phosphodiesterase inhibitor used in the treatment of claudication, is efficacious in the treatment of peripheral neuropathy, although this is unproven in humans. The main aim of this study was to assess the effects of cilostazol on neuropathic symptomatology in diabetic patients with peripheral arterial disease (PAD). METHODS: Diabetic patients with PAD were prospectively recruited to a randomized double-blinded placebo-controlled trial. Baseline clinical data were recorded prior to trial commencement following medical optimization. Neurological assessment included the Toronto Clinical Neuropathy Scoring system (TCNS) and vibration perception thresholds (VPT) with a neurothesiometer at baseline, 6 weeks, and 24 weeks. RESULTS: Twenty-six patients were recruited from December 2004 to January 2006, which included 20 males. Baseline patient allocation to treatment arms was matched for age, sex, and medical comorbidities. There was no significant difference in neurological assessment between the treatment groups using the TCNS and VPT at 6 and 24 weeks. CONCLUSIONS: Despite extensive animal-based evidence that cilostazol attenuates neuropathic symptomatology, our results do not support this effect in human diabetic PAD patients.

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.

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.

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.

Prosthetic stent graft infection after endovascular abdominal aortic aneurysm repair.

OBJECTIVE: The purpose of this report is to discuss the incidence, diagnosis, and management of stent graft infections after endovascular aneurysm repair (EVAR). METHODS: Data were collected from the hospital database and medical case notes for all patients with infected endografts after elective or emergency EVAR for abdominal aortic aneurysm (AAA) during the last 8 years in two university teaching hospitals in Northern Ireland. The data included the patient's age, gender, presentation of sepsis, treatment offered, and the ultimate outcome. The diagnosis of graft-related sepsis was established by a combination of investigations including inflammatory markers, labelled white cell scan, computed tomography (CT) scan, microbiology cultures, and postmortem examination. RESULTS: Graft-related septic complications occurred in six of 509 patients, including 433 elective repairs and 76 emergency endografts for ruptured AAA. Two patients presented with left psoas abscess and were treated successfully with extra-anatomic bypass and removal of the infected stent graft. Two more patients presented with infected graft without other evidence of intra-abdominal sepsis: one underwent successful removal of the infected prosthesis with extra-anatomical bypass, and the other was treated conservatively and died of progressively worsening sepsis. The fifth patient presented with unexplained fever and died suddenly, with a postmortem diagnosis of aortoenteric fistula and ruptured aneurysm. The last patient presented with an aortoenteric fistula, was treated conservatively in view of concurrent myelodysplasia, and died of possible aneurysm rupture. CONCLUSION: This report emphasizes the need for continued awareness of potential graft-related septic complications in patients undergoing EVAR of AAA. Attention to detail with regard to sterility and antibiotic prophylaxis during stent grafting and during any secondary interventions is vital in reducing the risk of infection. In addition, early recognition and prompt treatment are essential for a successful outcome.