Three-dimensional ultrasound volume and conventional ultrasound diameter changes are equally good markers of endoleak in follow-up after endovascular aneurysm repair.

INTRODUCTION: The main disadvantages of computed tomography angiography (CTA) in follow-up after endovascular aneurysm repair are the risks of contrast-induced renal impairment and radiation-induced cancer. Three-dimensional ultrasound is a new technique for volume estimation of the aneurysm sac. Some studies have reported promising results. The aim of this study was to evaluate the accuracy and precision of three-dimensional ultrasound aneurysm sac-volume estimates, and to explore whether volume and/or diameter changes on ultrasound can be used as markers of endoleak. METHODS: A single-center diagnostic accuracy study was performed. A total of 92 patients planned for endovascular aneurysm repair were prospectively and consecutively enrolled (2013-2016). Aneurysm sac diameter and volume were measured using CTA, conventional ultrasound, and three-dimensional ultrasound preoperatively and 1, 6, 12, and 24 months postoperatively. Three-dimensional ultrasound was performed with a commercially available electromechanical transducer. Patients with endoleak were observed 5 years after endovascular aneurysm repair. RESULTS: A total of 79 men and 13 women were included. Mean age was 74 years (57-92 years). Median follow-up was 24 months. Endoleak cases were observed for up to 55 months. Diameter measurements on conventional ultrasound correlated well with CT diameters (r = 0.9, P < .05, n = 347), and Bland-Altman analyses showed an upper limit of agreement of +0.5 cm and a lower limit of agreement of -0.8 cm. The mean difference was -0.13 cm ± 0.36 cm. Three-dimensional ultrasound volumes had a correlation with CTA diameters of r = 0.8 (P < .05, n = 347) and with three-dimensional CT volumes of r = 0.8 (P < .05, n = 155). Receiver operating characteristic analyses showed that the diameter and volume changes that led to reintervention were most accurate at 24-month follow-up, with area-under-the-curve percentage changes of 0.98 (two-dimensional ultrasound), 0.97 (three-dimensional ultrasound), and 0.97 (two-dimensional CT). DISCUSSION: Both diameter and volume changes can be used as markers for endoleak with excellent areas under the curve on receiver operating characteristic analyses. However, three-dimensional ultrasound volumes did not add any further diagnostic information. Conventional 2D diameter measurements were as accurate as volume changes as markers of endoleak. CONCLUSIONS: Type II endoleaks can safely be followed up using a simple diameter measurement on conventional ultrasound.

Contrast-enhanced ultrasound detects type II endoleaks during follow-up for endovascular aneurysm repair.

OBJECTIVE: Repeated computed tomography angiography (CTA) can be used during follow-up visits for endovascular aneurysm repair (EVAR) but leads to accumulated radiation exposure and may cause renal impairment. Therefore, the use of contrast-enhanced ultrasound (CEUS) has increased, and its ability to detect endoleaks has been promising. The aim of this study was to investigate the diagnostic accuracy of CEUS vs CTA for endoleak detection during EVAR follow-up. METHODS: Ninety-two patients with planned EVAR for abdominal aortic aneurysm were prospectively, consecutively enrolled. In total, 233 paired CTA and CEUS procedures were performed within the same day. Follow-up visits occurred 1 month, 6 months, 12 months, and 24 months postoperatively. RESULTS: Of 48 endoleaks discovered by CTA, 39 were also detected on CEUS, giving an overall sensitivity of 81.3% and specificity of 98.9%. All undetected endoleaks were minor, without clinical importance, and occurred in patients with high body mass index. CONCLUSIONS: In this study, CEUS was accurate for detecting type II endoleaks during follow-up visits for EVAR. Sensitivity was lower in obese patients. Doppler ultrasound has low sensitivity and seems to be unsuitable for the detection of endoleaks.

Corrosion and metal release from overlapping arterial stents under mechanical and electrochemical stress - An experimental study.

Intra-arterial stenosis due to atherosclerosis is often treated with endovascular balloon dilatation with a metal stent. Restenosis is common and is frequently treated with a new stent placed inside the existing one or the stents are placed with overlap to cover a larger area of the vessels. Observations of stent fractures, stent compression, accumulation of immunocompetent cells around stents have suggested the possibility of immunologic reactions to substances released from stents. An accelerated corrosion model was developed to study corrosion behaviour of commonly used surgical peripheral stents. Single nitinol stents (n = 6), connected stents of the same material (stent-in-stent, both nitinol, n = 7) and connected stents of dissimilar alloys (Nitinol with stainless steel stent inside, n = 7) were investigated. The stents were subjected to mechanical pulsatile radial strain (up to 8% strain at 1 Hz) and electrochemical stress (+112 mV vs. SCE). The release of nickel and titanium ions was compared. Scanning electron images were obtained. There was a higher release of nickel when combining two similar (range: 1382-8018 µg/L, p = 0.0012) and dissimilar (range: 170-2497 µg/L, p = 0.0023) stents compared to single stents (range: 0.4-216 µg/L). The concentration of titanium was low (range: 1.6-98.4 µg/L) with only a difference between the single and two similar stents (p = 0.0047). Deposits of corrosion products were clearly visible after fretting and pitting corrosion mainly on the Nitinol stents. Several mesh wires were fractured. The study demonstrated that mechanical strain combined with weak electric potential resulted in pronounced corrosion and fracture of stents, especially with overlapping stents. Single stents after pulsatile load released the lowest amount of ions. The combination of stents of the same material (Nitinol) had the highest release of metal ions.

HbA1c predicts long-term postoperative mortality in patients with unknown glycemic status at admission for vascular surgery: An exploratory study.

BACKGROUND: Peripheral arterial disease (PAD) and diabetes mellitus (DM) represent major public health challenges and are tightly associated. To facilitate early diagnosis, HbA1c has been implemented as the preferred diagnostic tool for the diagnosis of type 2 DM. In this study, we compared and evaluated HbA1c, fasting plasma glucose (FPG), and 2-hour post-load glucose values to determine which test best predicted mortality in patients with PAD. METHODS: In all, 273 PAD patients with unknown glycemic status admitted to Haukeland University Hospital for elective surgery between October 2006 and September 2007 were included in the study. All 273 patients underwent a standard oral glucose tolerance test (OGTT) in addition to determination of HbA1c; patients were then grouped into those with DM, intermediate hyperglycemia, and normoglycemia according to World Health Organization and International Expert Committee criteria. RESULTS: All-cause mortality was 40% over a 9-year follow-up period. After adjusting for age, sex, and relevant medication, HbA1c was a predictor for mortality (hazard ratio [HR] 1.54; 95% confidence interval [CI] 1.03-2.32]; P = 0.04). The association did not achieve statistical significance in a fully adjusted Cox regression model, although the effect estimation of HbA1c on all-cause mortality remained largely unchanged (HR 1.39; 95% CI 0.92-2.09; P = 0.13). The OGTT was not a predictor of long-term mortality. CONCLUSIONS: The results indicate that HbA1c is a useful marker in the preoperative screening of patients of unknown glycemic status at the time of admission for vascular surgery, and may identify people at high risk of long-term mortality following surgical treatment for PAD.

Correction to: HbA1c versus oral glucose tolerance test as a method to diagnose diabetes mellitus in vascular surgery patients.

The authors found errors in Table 1 after publication of the original article [1].The correct values for medical history of coronary artery disease (CAD) at baseline are 110 (40%) of all patients, 54 (35.5%) of patients categorized as having normoglycaemia, 42 (46.7%) of patients categorized as having intermediate hyperglycaemia, and 14 (42.4%) of patients categorized as having DM.All presented numbers and calculations in Table 1 are checked. No other errors were found. The presented errors did not affect results, scientific content or conclusions.The corrected Table 1 is presented in this erratum.The authors apologize for having presented this error in the original article.

Abdominal aortic aneurysms--glycaemic status and mortality.

AIMS: The prevalence of diabetes mellitus (DM) and mortality with respect to glycaemic status in patients with abdominal aortic aneurysms (AAA) was evaluated. Glycaemic status was assessed by an oral glucose tolerance test (OGTT) and by HbA1c. METHODS: Sixty-six patients with AAA admitted to the vascular surgery unit for elective surgery between October 2006 and September 2007 were included. Seven patients had previously known DM. OGTT and HbA1c results were available from 58 patients. The patients were categorized as having DM, prediabetes and normoglycaemia according to the WHO's and American Diabetes Association's criteria. RESULTS: The prevalence of newly diagnosed DM according to the OGTT and HbA1c results were 12% and 14% respectively. Mean follow-up time was 68 months and all-cause mortality 43%. HbA1c was an independent predictor for mortality in the DM category. Hazard ratio of all-cause mortality in the DM category defined by the HbA1c values was 6.35, 95% [CI 1.49-27.1]; p = 0.01. CONCLUSIONS: DM defined by HbA1c ≥ 6.5% is an important determinant of mortality following surgical treatment for AAA. Half the patients with AAA and DM were unaware of their DM diagnosis. All patients with AAA should be tested for DM using HbA1c. The results should be confirmed in a larger prospective study.

Effects of enoxaparin and dalteparin on proliferation and migration of patient-derived vascular smooth muscle cells.

BACKGROUND: Proliferation and migration are the two main processes of intimal hyperplasia: the primary cause of intermediate and late vascular graft failure. Low-molecular-weight heparins (LMWHs) inhibit these processes on vascular smooth muscle cells (VSMCs) in animal models, but have failed to improve patency of vascular grafts in clinical trials. Despite these findings, they are still used therapeutically to reduce intimal hyperplasia following vascular interventions. This study was designed to investigate the effects of LMWHs compared to unfractioned heparin in patient-derived VSMCs. MATERIAL AND METHODS: Arterial patient-derived VSMCs were used to study the effects of enoxaparin and dalteparin on proliferation, migration and mitogen-activated protein kinase extracellular signal-regulated kinase (MAPK-ERK) signal transduction. The VSMCs were treated with the LMWHs in a range of concentrations and evaluated using image based cell enumeration, real time migration monitoring and flow cytometry. Series treated with unfractioned heparin were included as positive controls and untreated series as negative controls. RESULTS: Neither enoxaparin nor dalteparin influenced proliferation and MAPK-ERK phosphorylation. Migration was reduced slightly by both LMWHs. Unfractioned heparin exhibited dose-dependent effects different from those of the LMWHs in all analyses. CONCLUSIONS: This study demonstrated a difference in proliferative and migratory effects between the two LMWHs and unfractioned heparin in patient-derived VSMCs. The effects corresponded to the MAPK-ERK activation, suggesting different mechanisms of action. These results can explain why clinical trials using LMWHs to prevent intimal hyperplasia have failed to observe a reduced incidence of restenosis and do not support prolonged therapeutic use to prevent intimal hyperplasia.

Perioperative cytokine response to infection associated with elective arterial surgery.

OBJECTIVE: The aim was to assess the cytokine response to acute inflammation and infection in vascular surgery. DESIGN OF STUDY: Single-center, prospective cohort study. METHODS: Blood samples from 96 consecutive patients undergoing elective vascular surgery were analyzed for C-reactive protein (CRP), total leukocyte counts (LPK), neutrophil CD64 expression, and cytokines using enzyme-linked immunosorbent assay. RESULTS: Of the 25 investigated cytokines, 22 had lower postoperative mean values compared to preoperative values. Interleukin (IL) 6 (IL-6) was the only cytokine that increased significantly postoperatively. Combined analysis of CRP and CD64 together with IL-6 or IL-10 showed an individually unique association with postoperative infection (P < .05). CONCLUSION: We have shown a positive correlation with perioperative infection for the proinflammatory cytokines and the anti-inflammatory cytokine IL-10 as well as a number of chemokines. To our knowledge, this is the first report linking IL-10 and chemokine plasma levels to perioperative infection in vascular surgery.

HbA1c versus oral glucose tolerance test as a method to diagnose diabetes mellitus in vascular surgery patients.

BACKGROUND: The diagnosis of diabetes mellitus (DM) is based on either fasting plasma glucose levels or an oral glucose tolerance test (OGTT). Recently, an HbA1c value of ≥ 48 mmol/mol (6.5%) has been included as an additional test to diagnose DM. The purpose of this study was to validate HbA1c versus OGTT as a method to diagnose DM in vascular surgery patients. METHODS: The study population consisted of 345 patients admitted consecutively due to peripheral arterial disease. Sixty-seven patients were previously diagnosed with DM. Glucose levels of OGTT and HbA1c values were analyzed in 275 patients. The OGTT results were categorized into three groups according to the World Health Organization 1999 criteria: 1) DM defined as fasting plasma glucose (FPG) ≥ 7.0 mmol/L and/or two-hour value (2-h-value) ≥ 11.1 mmol/L; 2) intermediate hyperglycaemia, which consists of IGT (FPG < 7.0 mmol/L and a 2-h-value between 7.8 mmol/L and 11.1 mmol/L), and IFG (fasting glucose value between 6.1 mmol/L and 7.0 mmol/L with a normal 2-h-value); and 3) normal glucose metabolism defined as FPG < 6.1 mmol/L and a 2-h-value < 7.8 mmol/L. RESULTS: Of the 275 patients on whom OGTT was performed, 33 were diagnosed with DM, 90 with intermediate hyperglycaemia and 152 had normal glucose metabolism. An HbA1c value of ≥ 48 mmol/mol (6.5%) detected DM with a 45.5% sensitivity and a 90% specificity compared with the OGTT results. Combining the measurements of the HbA1c value with the fasting plasma glucose level (≥7.0 mmol/L) increased the sensitivity to 64%. The total prevalence of DM and intermediate hyperglycaemia was 85% based on HbA1c values and 45% based on the OGTT. CONCLUSIONS: Compared with the OGTT the HbA1c cut-off value of ≥ 48 mmol/mol (6.5%) had a 45.5% sensitivity to diagnose DM in patients with peripheral arterial disease. OGTT and HbA1c categorized different individuals with DM and intermediate hyperglycaemia. The total prevalence of pathologic glucose metabolism was substantially higher based on HbA1c values than based on OGTT. The high prevalence of DM and intermediate hyperglycaemia when using HbA1c in this study may reflect a high chronic glycaemic burden in patients with peripheral arterial disease. Further studies on vascular surgery patients are needed to identify which method, OGTT or HbA1c, is the better in predicting DM and future clinical development of vascular disease. TRIAL REGISTRATION: REK vest 14109.

Supplementation with orange and blackcurrant juice, but not vitamin E, improves inflammatory markers in patients with peripheral arterial disease.

Inflammation and endothelial activation are associated with an increased risk of CVD and epidemiological evidence suggests an association between levels of markers of inflammation or endothelial activation and the intake of fruit. Also, vitamin E, a fat-soluble antioxidant, has anti-inflammatory properties. We performed a randomised 2 x 2 factorial, crossover trial to determine the effect of orange and blackcurrant juice (500 ml/d) and vitamin E (15 mg RRR-alpha-tocopherol/d) supplementation on markers of inflammation and endothelial activation in forty-eight patients with peripheral arterial disease. Patients were randomly allocated to two dietary supplements from the four possible combinations of juice and vitamin E: juice+vitamin E; juice+placebo; reference beverage (sugar drink)+vitamin E; and reference beverage+placebo. The supplementations were given for 28 d, separated by a 4-week wash-out period. Analysis of main effects showed that juice decreased C-reactive protein (CRP) by 11% and fibrinogen by 3% while the reference drink increased CRP by 13% and fibrinogen by 2% (P<0.008 and P<0.002, respectively). No significant differences were measured for IL-6 and the endothelial activation markers von Willebrand factor, tissue-plasminogen activator and plasmin activator inhibitor-1. Vitamin E supplementation had no significant effects on the various markers. We observed no significant interaction between juice and vitamin E. In this study, orange and blackcurrant juice reduced markers of inflammation, but not markers of endothelial activation, in patients with peripheral arterial disease, relative to sugar drinks.

No influence of increased intake of orange and blackcurrant juices and dietary amounts of vitamin E on paraoxonase-1 activity in patients with peripheral arterial disease.

BACKGROUND: Paraoxonase-1 (PON1) is an antioxidative enzyme associated with HDL and its serum activity is associated with risk of cardiovascular disease. The interindividual variation in PON1 activity is partly determined by genetic factors, such as polymorphisms in the PON1 gene, but also by dietary factors like the antioxidants. AIM OF THE STUDY: We examined the effect of antioxidant-rich orange and blackcurrant juices and vitamin E supplement on PON1 activity in patients with peripheral arterial disease. Furthermore, we studied whether genetic polymorphisms in the PON1 gene predicted the change in PON1 activity. METHODS: The study was designed as a cross-over trial with 48 participants who received two of the four possible treatments: (1) 250 ml orange juice and 250 ml blackcurrant juice; (2) 15 mg vitamin E; (3) 250 ml orange juice and 250 ml blackcurrant juice and 15 mg vitamin E; or (4) control/placebo (energy-equivalent sugar-containing beverage). The treatments were given for 28 days, separated by a 4-week wash-out period. RESULTS: The PON1 activity was not affected by juice or vitamin E supplement neither was there evidence of synergetic effects. However, a statistically significant interaction was observed between treatment and PON1 genotype, such that PON1 activity increased after juice alone in patients carrying the PON1 L55-allele. Results need to be interpreted with care since the study population was relatively small. CONCLUSION: Consumption of orange and blackcurrant juice and vitamin E supplement does not affect the activity of PON1 in patients with peripheral arterial disease. However, a gene-diet interaction may be present.

Pseudoaneurysm of the abdominal aorta due to a needle-like osteophyte on the first lumbar vertebra.

A 46-year-old woman was admitted with acute abdominal pain radiating to the back. Computed tomography examinations showed a needle-thin perforation of the aorta, opposite the origin of the superior mesenteric artery, with a pseudoaneurysm. A needle-sharp spinal osteophyte was located exactly opposite the perforation. There was no sign of infection, and the perforation seemed to have been caused by the osteophyte. This aortic perforation occurred without any major trauma, but repeated minor occupational trauma to her abdomen may have played an etiologic role. The pseudoaneurysm and adjacent aorta were exposed through a thoracolaparotomy. The aortic wall was normal, with good tensile strength; therefore, the perforation in the aortic wall was sutured with a double vascular suture, and the osteophyte was resected. To our knowledge, aortic perforation due to a vertebral osteophyte in the absence of major trauma has not previously been described.

[Intermittent claudication--diagnosis and treatment]. / Claudicatio intermittens--diagnostikk og behandling.

BACKGROUND: Intermittent claudication occurs in 5% of the population over 60 years, and may involve reduced walking distance, pain and a reduced quality of life. The mortality rate is 5% per year and the annual amputation rate 1%. This review article gives an update on diagnosis and medical, endovascular and surgical treatment of intermittent claudication. MATERIAL AND METHODS: The article is based on publications found on Pubmed, supplemented by clinical experience. RESULTS AND INTERPRETATION: The aims of medical, endovascular and surgical treatments are to enable the patient to walk further, obtain an improved quality of life and to live longer. Patients should first be treated medically. Endovascular treatment or open surgery, are options for patients with reduced quality of life due to limited walking distance. The treatment choice depends on the location of the arterial lesions and if the patient has any other illness.

Treatment of a hepatic artery aneurysm by endovascular stent-grafting.

Aneurysms of the visceral arteries are rare. Traditional treatment has been surgical or endovascular with coil embolization. Recently, however, reports on endovascular therapy with stent-grafts have been published. We report the case of a 61-year-old man who was successfully treated with a stent-graft for a symptomatic combined celiac/hepatic artery aneurysm.

Flow measurement before and after papaverine injection in above-knee prosthetic femoropopliteal bypass.

OBJECTIVE: To investigate the value of intraoperative blood flow measurements on early and long-term patency of above-knee prosthetic femoropopliteal bypass. METHODS: Flow was measured with a transit time flowmeter before (basal flow) and after an intragraft injection of papaverine (papaverine flow) in 87 operations (86 patients) between January 1990 and December 2001. Sixty-one grafts were of polyester, and 26 were of polytetrafluoroethylene. The operations were done under epidural anesthesia. The preoperative angiographic run-off score and clinical risk factors were recorded. Patency rates were analyzed with the product limit method and compared with the log-rank test. Variables found to be near significantly related to patency rates (P < .1) were included in a multivariate analysis performed with the Cox proportional hazard model. RESULTS: Basal flow measurements were not related to patency. The 2- and 5-year patency rates for grafts with a papaverine flow < or = 500 mL/min were 48% and 18% compared with 66% and 52% for grafts with a papaverine flow > or = 500 mL/min. These differences were statistically significant (P = .012, hazard ratio, 2.6). Two- and 5-year patency rates for smokers vs nonsmokers were 44% and 18% vs 69% and 54%. The patency rates for patients with poor vs good run-off were 42% and 27% vs 66% and 31%. Smoking (P = .008, hazard ratio, 2.75) and poor run-off score (P = .009, hazard ratio, 2.38) were found to be independent risk factors for reduced patency rates. Poor run-off score did not correlate with low values of measured basal or papaverine flow. CONCLUSIONS: Papaverine flow of < or = 500 mL/min is associated with reduced mid- and long-term patency rates. Additional antithrombotic medication and frequent follow-up for these grafts should be considered. The inferior patency rates of smokers and patients with poor run-off indicate that prosthetic bypass is less suitable for these groups of patients.

[Pseudoaneurysm in the femoral artery after repeated hip surgery--combined thrombolytic and surgical treatment]. / Pseudoaneurisme i arteria femoralis communis efter gentagen hoftekirurgi--kombineret trombolytisk og kirurgisk behandling.

Pseudoaneurysms in the femoral artery seldom occur spontaneously. Commonly they occur secondarily to trauma or as a complication to surgery or angiography. This study reports the occurrence of a pseudoaneurysm in the left common femoral artery. The patient, a 54-year-old woman, had undergone leftsided hip replacement five years before and several subsequent operations on the left hip due to dislocation and loose cup. She was admitted with a palpable non-pulsating mass in her left inguinal region and pain and cyanosis in her left lower limb. Ultrasound and angiography showed a pseudoaneurysm with occlusion of the popliteal, the tibial, and the peroneal arteries. The patients was successfully treated with actilysis for 48 hours and subsequent vascular surgery.

Intraoperative angioscopy may improve the outcome of in situ saphenous vein bypass grafting: a prospective study.

OBJECTIVE: To find out whether intraoperative angioscopic assistance has any effect on graft outcome in patients with critical leg ischemia. MATERIAL AND METHODS: One hundred one patients requiring a below-knee bypass were assigned to undergo in situ saphenous vein bypass with or without intraoperative angioscopic assistance; otherwise treated similarly including preoperative duplex vein mapping, intraoperative graft flow measurements, and angiography. Data on operative details, morbidity, hospital stay, and graft patency were collected prospectively and compared. All patients were followed up for 12 months. RESULTS: The group that underwent angioscopy (A) and the control group (B) were similar in all respects, except for the number of patients enrolled in the groups (32 and 69, respectively). Angioscopy revealed incompletely destructed valves in 34 patients (range, 0 to 5; mean 1), undiagnosed vein branches in 111 patients (mean 4.3), and partly occluding thrombus in 5 patients. The number of postoperative arteriovenous fistulas with signs of failing graft and a need for angiographic or surgical reintervention were significantly higher in group B (P <.0001). The 1-year primary patency rate was significantly better in group A (P <.01), but the primary assisted and secondary patency rates did not differ between the groups. CONCLUSIONS: Angioscopic assistance has an impact on primary graft patency, minimizes the risk for graft failure and thus reduces the need for reintervention by allowing identification of persistent saphenous vein branches, incomplete valve destruction, and partly occluding graft thrombus without adding extra operative time.