Monoplane versus biplane fluoroscopy in patients undergoing fenestrated/branched endovascular aortic repair.

OBJECTIVE: Endovascular aortic repair (EVAR) with fenestrated (F-EVAR) or branched (B-EVAR) endografts represents an indispensable tool of modern patient care in vascular surgery. The purpose of this retrospective study was to evaluate the center's initial experience of F/B-EVAR procedures performed under biplane angiography guidance compared with a historical control group. METHODS: From January 2020 to March 2022, 80 consecutive patients underwent F/B-EVAR under general anesthesia at a single institution. As from January 2021, the deployment of complex stent grafts was performed using an alternative intraoperative imaging modality-a biplane fluoroscopy and angiography. The cohort was divided into monoplane (MPA) and biplane (BPA) groups according to the imaging modality applied. The end points were operation time, fluoroscopy time, radiation exposure, dose of contrast agent, and technical success. RESULTS: The MPA group included 59 patients (78% male; median age; 74 years; interquartile range [IQR], 66-78 years) and the BPA group 21 patients (85.7% males; median age, 75 years; IQR, 69-79 years). Operation time (median, 320 minutes; IQR, 266-376 minutes) versus (median, 275 minutes; IQR, 216-333 minutes) was significantly lower in the BPA group (P = .006). The median fluoroscopy time (median, 82 minutes; IQR, 57-110 minutes vs median, 68 minutes; IQR, 54-92 minutes), contrast agent volume applied (median, 220 mL; IQR, 179-250 mL vs median, 200 mL; IQR, 170-250 mL), and radiation dose (dose-area product, median, 413 Gy × cm2; IQR, 249-736 Gy × cm2; vs median, 542 Gy × cm2; IQR, 196-789 Gy × cm2) were similar in both groups. Technical success of 96.6% (57/59 cases) versus 100% (21/21 cases) could be achieved in MPA and BPA group, respectively. CONCLUSIONS: F/B-EVAR procedures performed under BPA guidance were associated with a significant decrease in operation time.

The prognostic impact of vascular calcification on abdominal aortic aneurysm progression.

OBJECTIVE: The maximal aortic diameter is currently the only clinically applied predictor of abdominal aortic aneurysm (AAA) progression. It is known that the risk of rupture is associated with aneurysm size; hence, accurate monitoring of AAA expansion is crucial. Aneurysmal vessel wall calcification and its implication on AAA expansion are insufficiently explored. We evaluated the vascular calcification using longitudinal computed tomography angiographies (CTA) of patients with an AAA and its association with AAA growth. METHODS: We conducted a retrospective study of 102 patients with an AAA with a total of 389 abdominal CTAs at 6-month intervals, treated and followed at the Division of Vascular Surgery, Department of General Surgery, Medical University of Vienna. Digitally stored CTAs were reviewed for vascular calcification (volume and score) of the infrarenal aorta and common iliac arteries as well as for morphometric AAA analysis. In the prognostic setting, slow versus fast AAA progression was defined as a less than 2 mm or a 2-mm or greater increase in AAA diameter over 6 months. In addition, to analyze the association of vascular calcification and the AAA growth rate with longitudinal monitoring data, a specifically tailored log-linear mixed model was used. RESULTS: An inverse relation of increased abdominal vessel wall calcification and short-term AAA progression was detected. Compared with fast progressing AAA, the median calcification volume of the infrarenal aorta (1225.3 mm³ vs 519.8 mm³; P = .003), the median total calcification volume (2014.1 mm³ vs 1434.9 mm³; P = .008), and the median abdominal total customized Agatston calcium (cAC) score (1663.5 vs 718.4; P = .003) were significantly increased in slow progressing AAA. Importantly, a log-linear mixed model efficiently predicted AAA expansion based on current diameter and abdominal total cAC score (P = .042). CONCLUSIONS: We assessed the prognostic value of CTA-measured vascular calcification for AAA progression. Increased vascular calcification stabilizes the aortic aneurysmal wall and likely protects against progressive AAA expansion, resulting in a significant decrease of aneurysm growth over time. As a consequence, this may have implications for rupture risk, mortality, morbidity, and cost.

Left Renal Vein Division for Juxtarenal Aortic Exposure: Influence on Renal Function and Role of the Communicating Lumbar Vein.

BACKGROUND: In this study, we evaluate the outcome of renal function in patients undergoing juxtarenal abdominal aortic aneurysm repair with or without division of the left renal vein with special focus on the role of the communicating lumbar vein. METHODS: A retrospective analysis of prospectively collected data of 110 patients undergoing elective juxtarenal abdominal aortic aneurysm repair between 2000 and 2018 was performed. The demographic characteristics and comorbidities were reviewed in detail and the renal function was analysed pre- and post-operatively. The cohort of patients was split into group A (left renal vein divided) and B (left renal vein mobilised). Group A was further sub-analysed regarding the presence of a communicating lumbar vein on preoperative imaging data (group A+ = vein present, group A- = no communicating lumbar vein present). RESULTS: The patients were matched well regarding their demographic characteristics and comorbidities. In the analysis of renal function, no statistically significant difference could be detected between group A and B. In the sub-analysis of group A, the group with a communicating lumber vein (group A+) turned out to have a significantly better renal function in the long term (sCrea 0.87 vs. 1.51; p = 0.016). CONCLUSION: Ligation of the left renal vein is a safe procedure in surgery of juxtarenal aortic aneurysms regarding the outcome of the renal function. A communicating lumbar vein between the left renal vein and the left ascending lumbar vein seems to play a key role to provide venous drainage after division of the left renal vein.

Novel prefabricated bovine pericardial grafts as alternate conduit for septic aortoiliac reconstruction.

OBJECTIVE: Infection of prosthetic aortic grafts represents a serious complication with high morbidity and mortality. Replacement with autologous material is recommended; however, in its absence, biological material should be favored. In the present retrospective cohort study, we evaluated the short- and midterm results with the use of commercially available prefabricated bovine pericardium grafts (BPGs) used for the management of aortic graft infection or aortic reconstructive surgery in the presence of systemic infection. METHODS: We performed a retrospective analysis of patients in whom BPGs had been used for aortic reconstruction at two vascular centers. Prefabricated vascular pericardium grafts were preferred over other biological reconstruction techniques for selected cases. Comorbidities, procedure-related details, perioperative morbidity, clinical outcomes, and mortality were analyzed. RESULTS: From 2014 to 2019, 21 patients had received BPGs at two Austrian vascular centers. Their median age was 63 years (interquartile range [IQR], 55-71 years), the patients were predominantly male (76%), and the median body mass index was 25.3 kg/m2 (IQR, 21.7-27.3 kg/m2). The major comorbidities included arterial hypertension, peripheral artery disease, smoking, and chronic pulmonary disease. The indications for surgery were vascular graft or endograft infection in 62% and aortic reconstruction in the presence of systemic infection in 38%. Three patients (14%) had aortoenteric fistulas. Surgery was technically successful in all cases. The median follow-up was 21.6 months (IQR, 6.0-34.6 months). The 30-day mortality was 9.5%. The 1- and 2-year overall survival was 84% and 75%, respectively. Of the 21 patients, 89% had remained free of recurrent infection. One of the two reinfections had resolved after treatment of the underlying focus. At 2 years, the primary and assisted primary patency rates were 86% and 94%, respectively. No limbs were lost during follow-up. CONCLUSIONS: Prefabricated BPGs represent a promising alternative for the management of aortic graft infections and aortoiliac reconstruction in the presence of systemic infection.

Neutrophil Gelatinase Associated Lipocalin (NGAL) for Identification of Unstable Plaques in Patients with Asymptomatic Carotid Stenosis.

OBJECTIVE: Neutrophil gelatinase associated lipocalin (NGAL) and matrix metalloproteinase (MMP)-9/NGAL complex were investigated in asymptomatic patients with carotid artery stenosis including gender specific differences aiming at vulnerable plaques prone to embolisation. METHODS: Serum NGAL and MMP-9/NGAL levels were analysed in 83 patients with asymptomatic carotid artery stenosis. Pre-operative ultrasound and post-endarterectomy histology of carotid atherosclerotic lesions were evaluated. RESULTS: Patients with vulnerable plaques, as determined by ultrasound (plaques with decreased echogenicity) and histological analysis (type VI according to the classification of the American Heart Association), displayed the highest levels of NGAL and MMP-9/NGAL complex (p = .0003 and p = .0078, respectively). Grade VI plaques were primarily detected in patients with "soft" plaques (12 type VI plaques in 25 patients), but also in patients with mixed (four of 19) and calcified (three of 39) plaques according to ultrasound. Higher grade carotid artery stenosis (≥90%) was not associated with elevated NGAL levels. The receiver operating characteristic curve analysis detecting grade VI lesions yields an area under the curve (AUC) = 0.85, with respect to soft plaque on ultrasound the AUC = 0.86. There were no gender specific differences in levels of NGAL 80.9 (37.7) ng/mL in women vs. 76.7 (36.3) ng/mL in men, p = .607) nor of MMP-9/NGAL 33.0 (18.2-55.5) ng/mL in women vs. 36.7 (20.2-54.0) ng/mL in men, p = .969. Likewise, there were no gender associated differences in vulnerable plaque characteristics: either for grade VI plaques (17.9% vs. 27.3%, p = .582) or for the presence of soft plaques as evaluated by ultrasound (35.9% vs. 25%, p = .503). CONCLUSION: Circulating NGAL and MMP-9/NGAL are significantly increased in asymptomatic patients with vulnerable carotid atherosclerotic plaques independent of gender. Accordingly, serum NGAL may be proposed as a valuable biomarker for the detection of unstable carotid plaques in asymptomatic patients, who can then be selected for early carotid endarterectomy or stenting.

NGAL and MMP-9/NGAL as biomarkers of plaque vulnerability and targets of statins in patients with carotid atherosclerosis.

BACKGROUND: Neutrophil gelatinase associated lipocalin (NGAL) is expressed in atherosclerotic lesions and was recently implicated in the pathogenesis of cardiovascular pathologies. Statins are known to exert stabilizing effects on atherosclerotic plaque. The aims of our study were (1) to investigate the association of serum NGAL and metalloproteinase (MMP)-9/NGAL complex with the vulnerability of the atherosclerotic plaque, and (2) to reveal the effects of statin treatment on circulating NGAL and MMP-9/NGAL levels in patients with carotid artery stenosis. METHODS: We examined the levels of NGAL and MMP-9/NGAL in blood samples from 136 patients with carotid artery stenosis by specific enzyme-linked immunosorbent assays. RESULTS: Patients with vulnerable plaques, as determined by ultrasound (plaques with decreased echogenicity) and histological analysis (type VI according to the classification of American Heart Association [AHA]), displayed the highest levels of NGAL (both p<0.0001) and MMP-9/NGAL complex (p=0.0004 and p=0.004, respectively). Moreover, patients with symptomatic carotid atherosclerosis had significantly higher NGAL levels compared to asymptomatic patients (p=0.0007). The statin-treated group (n=108) demonstrated lower NGAL (73.9 vs. 128.0 µg/L, p<0.0001) and MMP-9/NGAL (28.9 vs. 40.6 µg/L, p=0.046) as compared to the non-statin group (n=28). Furthermore, in multivariate regression analysis NGAL, but not MMP-9/NGAL levels, were independently associated with symptomatic carotid artery stenosis. In addition, statin treatment was independently associated with lower NGAL levels. CONCLUSIONS: Circulating NGAL and MMP-9/NGAL are associated with plaque vulnerability in patients with carotid artery stenosis. Statin treatment could contribute to plaque stabilization by reducing circulating NGAL and MMP-9/NGAL levels.

Red blood cell transfusion-related dynamics of extracellular vesicles in intensive care patients: a prospective subanalysis.

Extracellular vesicles (EVs) accumulate during packed red blood cell (PRBC) storage. To date, the involvement of EVs in transfusion-related immunomodulation (TRIM) has not been prospectively evaluated in intensive care unit (ICU) patients. This was a prospective subanalysis of a recent observational feasibility study in postoperative ICU patients after: (1) open aortic surgery (Aorta), (2) bilateral lung transplantation (LuTx), and (3) other types of surgery (Comparison). Patient plasma was collected three times each before and after leukoreduced PRBC transfusion at 30-min intervals. The total number of EVs and EVs derived from erythrocytes (EryEVs), total platelets (total PEVs), activated platelets, granulocytes (GEVs), monocytes, and myeloid cells in PRBC samples and patient plasma were analyzed by flow cytometry. Statistical analysis was performed by Spearman's correlation test, linear mixed models and pairwise comparisons by Wilcoxon matched-pairs test. Twenty-three patients (Aorta n = 5, LuTx n = 9, Comparison n = 9) were included in the final analysis. All EV subgroups analyzed were detectable in all PRBCs samples (n = 23), but concentrations did not correlate with storage time. Moreover, all EVs analyzed were detectable in all plasma samples (n = 138), and EV counts were consistent before transfusion. Concentrations of total EVs, EryEVs, total PEVs, and GEVs increased after transfusion compared with baseline in the entire cohort but not in specific study groups. Furthermore, the change in plasma EV counts (total EVs and EryEVs) after transfusion correlated with PRBC storage time in the entire cohort. Extracellular vesicles were detectable in all PRBC and plasma samples. Individual EV subtypes increased after transfusion in the entire cohort, and in part correlated with storage duration. Future clinical studies to investigate the role of EVs in TRIM are warranted and should anticipate a larger sample size.Trial registration: Clinicaltrials.gov: NCT03782623.

Successful repair of bilateral common carotid artery dissections from hanging.

The management of blunt carotid artery dissections caused by hanging remains controversial, especially with regard to diagnostic work-up and treatment options. We present 2 men, 49 and 41 years of age, who were treated for bilateral common carotid artery dissection caused by strangulation. In the first patient, additional cricotracheal separation and blunt thyroid gland trauma was observed. Bilateral saphenous vein graft interposition was accomplished in both patients. In the first patient, tracheal repair and suture of the thyroid gland completed the procedure. At 1 year of follow-up, both patients were capable of managing their lives independently. A systematic review of the literature on managing near-hanging and nonfatal strangulation victims is included in this report to allow this case series to be put into perspective.

Abdominal Aortic Aneurysm Detection in Bioelectrical Impedance Cardiovascular Screenings-A Pilot Study.

Screening and diagnosing abdominal aortic aneurysms (AAA) are currently dependent on imaging studies such as ultrasound or computed tomography angiography. All imaging studies offer distinct advantages but also suffer from inherent limitations such as examiner dependency or ionizing radiation. Bioelectrical impedance analysis has previously been investigated with respect to its use in the detection of several cardiovascular and renal pathologies. The present pilot study assessed the feasibility of AAA detection based on bioimpedance analysis. In this single-center exploratory pilot study, measurements were conducted among three different cohorts: patients with AAA, end-stage renal disease patients without AAA, and healthy controls. The device used in the study, CombynECG, is an open-market accessible device for segmental bioelectrical impedance analysis. The data was preprocessed and used to train four different machine learning models on a randomized training sample (80% of the full dataset). Each model was then evaluated on a test set (20% of the full dataset). The total sample included 22 patients with AAA, 16 chronic kidney disease patients, and 23 healthy controls. All four models showed strong predictive performance in the test partitions. Specificity ranged from 71.4 to 100%, while sensitivity ranged from 66.7 to 100%. The best-performing model had 100% accuracy for classification when applied to the test sample. Additionally, an exploratory analysis to approximate the maximum AAA diameter was conducted. An association analysis revealed several impedance parameters that might possess predictive ability with respect to aneurysm size. AAA detection via bioelectrical impedance analysis is technically feasible and appears to be a promising technology for large-scale clinical studies and routine clinical screening assessments.

Comparing maximum diameter and volume when assessing the growth of small abdominal aortic aneurysms using longitudinal CTA data: cohort study.

BACKGROUND: Monitoring of abdominal aortic aneurysms (AAAs) is currently based on serial measurements of maximum aortic diameter. Additional assessment of aneurysm volume has previously been proposed to possibly improve growth prediction and treatment decisions. To evaluate the use of supplementing volume measurements, the authors aimed to characterise the growth distribution of AAA volume and to compare the growth rates of the maximum diameter and volume at the patient level. METHODS: Maximum diameter and volume were monitored every 6 months in 84 patients with small AAAs, with a total of 331 computed tomographic angiographies (with initial maximum diameters of 30-68 mm). A previously developed statistical growth model for AAAs was applied to assess the growth distribution of volume and to compare individual growth rates for volume and for maximum diameter. RESULTS: The median (25-75% quantile) expansion in volume was 13.4 (6.5-24.7) % per year. Cube root transformed volume and maximum diameter showed a closely linear association with a within-subject correlation of 0.77. At the surgery threshold maximum diameter of 55 mm, the median (25-75% quantile) volume was 132 (103-167) ml. In 39% of subjects, growth rates for volume and maximum diameter were equivalent, in 33% growth was faster in volume and in 27% growth was faster in maximum diameter. CONCLUSION: At the population level, volume and maximum diameter show a substantial association such that the average volume is approximately proportional to the average maximum diameter raised to a power of three. At the individual level, however, in the majority of patient's AAAs grow at different pace in different dimensions. Hence, closer monitoring of aneurysms with sub-critical diameter but suspicious morphology may benefit from complementing maximum diameter by volume or related measurements.

Red blood cell transfusion-related eicosanoid profiles in intensive care patients-A prospective, observational feasibility study.

Introduction: Eicosanoids are bioactive lipids present in packed red blood cells (PRBCs), and might play a role in transfusion-related immunomodulation (TRIM). We tested the feasibility of analyzing eicosanoid profiles in PRBC supernatant and in plasma samples of postoperative intensive care unit (ICU) patients transfused with one unit of PRBCs. Methods: We conducted a prospective, observational feasibility study enrolling postoperative ICU patients: 1) patients treated with acetylsalicylic acid following abdominal aortic surgery (Aorta); 2) patients on immunosuppressants after bilateral lung transplantation (LuTx); and 3) patients undergoing other types of major surgery (Comparison). Abundances of arachidonic acid (AA) and seven pre-defined eicosanoids were assessed by liquid chromatography and tandem mass spectrometry. PRBC supernatant was sampled directly from the unit immediately prior to transfusion. Spearman's correlations between eicosanoid abundance in PRBCs and storage duration were assessed. Patient plasma was collected at 30-min intervals: Three times each before and after transfusion. To investigate temporal changes in eicosanoid abundances, we fitted linear mixed models. Results: Of 128 patients screened, 21 were included in the final analysis (Aorta n = 4, LuTx n = 8, Comparison n = 9). In total, 21 PRBC and 125 plasma samples were analyzed. Except for 20-hydroxyeicosatetraenoic acid (HETE), all analyzed eicosanoids were detectable in PRBCs, and their abundance positively correlated with storage duration of PRBCs. While 5-HETE, 12-HETE/8-HETE, 15-HETE, 20-HETE, and AA were detectable in virtually all plasma samples, 9-HETE and 11-HETE were detectable in only 57% and 23% of plasma samples, respectively. Conclusions: Recruitment of ICU patients into this transfusion study was challenging but feasible. Eicosanoid abundances increased in PRBC supernatants during storage. In plasma of ICU patients, eicosanoid abundances were ubiquitously detectable and showed limited fluctuations over time prior to transfusion. Taken together, larger clinical studies seem warranted and feasible to further investigate the role of PRBC-derived eicosanoids in TRIM.

Evaluation of national institute for health and care excellence guidance for ruptured abdominal aortic aneurysms by emulating a hypothetical target trial.

Objective: This retrospective study evaluates the performance of UK National Institute for Health and Care Excellence (NICE) Guidelines on management of ruptured abdominal aortic aneurysms in a "real world setting" by emulating a hypothetical target trial with data from two European Aortic Centers. Methods: Clinical data was retrospectively collected for all patients who had undergone ruptured endovascular aneurysm repair (rEVAR) and ruptured open surgical repair (rOSR). Survival analysis was performed comparing NICE compliance to usual care strategy. NICE compliers were defined as: female patients undergoing rEVAR; male patients >70 years old undergoing rEVAR; and male patients ≤70 years old undergoing rOSR. Hemodynamic instability was considered additionally. Results: This multicenter study included 298 patients treated for rAAA. The majority of patients were treated with rOSR (186 rOSR vs. 112 rEVAR). Overall, 184 deaths (68 [37%] with rEVAR and 116 [63%] with rOSR) were observed during the study period. Overall survival under usual care was 69.2% at 30 days, 56.5% at one year, and 42.4% at 5 years. NICE compliance gave survival outcomes of 73.1% at 30 days, 60.2% at 1 year and 42.9% at 5 years. The risk ratios at these time points, comparing NICE-compliance to usual care, were 0.88, 0.92 and 0.99, respectively. Conclusions: We support NICE recommendations to manage men below the age of 71 years and hemodynamic stability with rOSR. There was a slight survival advantage for NICE compliers overall, in men >70 years and women of all ages.

Prospective evaluation of high-resolution MRI using gadofosveset for stent-graft planning: comparison with CT angiography in 30 patients.

OBJECTIVE: The purpose of our study was to compare high-resolution gadofosveset-enhanced MR angiography (MRA) with the reference standard CT angiography (CTA) in planning endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms. SUBJECTS AND METHODS: Thirty consecutive patients were included in this prospective study. CTA was performed routinely before EVAR for stent-graft implantation planning and selection. In addition, first-pass and, after a delay of 10 minutes, steady-state MRA were performed using the blood pool contrast agent gadofosveset for study purposes. Standard diameter and length parameters for stent-graft evaluation rendered from CTA and MRA were compared. According to the results of MRA measurements, stent-grafts were selected for each patient and compared with the device actually implanted. Image quality was assessed using subjective image quality parameters. RESULTS: Diameter and length measurements showed small but significant differences (p < 0.001) between MRA and CTA. Stent-graft selection according to these measurements showed 100% concordance between both modalities. Subjective imaging parameters showed significantly better results for CTA compared with MRA (p < 0.001). CONCLUSION: In this study, MRA using a blood pool contrast agent has shown the ability to provide reliable and exact measurements before EVAR, allowing noninvasive planning of the intervention despite lower image-quality and without the disadvantages of ionizing radiation and nephrotoxicity.

Complement Factor C5a Is Increased in Blood of Patients with Abdominal Aortic Aneurysm and Has Prognostic Potential for Aneurysm Growth.

In this observational case-control study, circulating levels of complement factors C3a and C5a and leukotriene B4 (LTB4) were analysed in abdominal aortic aneurysm (AAA) patients regarding their association with diagnosis and prognosis. Serum C5a was significantly raised in AAA patients compared to healthy controls-median 84.5 ng/ml (IQR = 37.5 ng/ml) vs. 67.7 ng/ml (IQR = 26.2 ng/ml), p = 0.007-but was not elevated in patients with athero-occlusive disease. Serum C5a levels correlated significantly with the increase in maximum AAA diameter over the following 6 months (r = 0.319, p = 0.021). The median growth in the lowest quartile of C5a (< 70 ng/ml) was 50% less compared to the highest C5a quartile (> 101 ng/ml): 1.0 mm/6 months (IQR = 0.8 mm) vs. 2.0 mm/6 months (IQR = 1.5 mm), p = 0.014. A log-linear mixed model predicted AAA expansion based on current diameter and C5a level. To our knowledge, this is the first study linking complement activation, in particular C5a serum level, with AAA progression.

Inverse probability of treatment analysis of open vs endovascular repair in ruptured infrarenal aortic aneurysm - Cohort study.

BACKGROUND: To compare open repair (OR) with EVAR for the management of ruptured infrarenal abdominal aortic aneurysms (RAAA) in a cohort study over a time period of 15 years with inverse probability of treatment weights. MATERIAL AND METHODS: From 2000/01 through 2015/12 136 patients were treated for RAAA, 98 (72.1%) underwent OR, 38 (27.9%) were treated with EVAR. Thirty-day and long-term mortality (survival) were analyzed in this IRB-approved retrospective cohort study. Treatment modalities were compared using inverse probability of treatment weights to adjust for imbalances in demographic data and risk factors. RESULTS: EVAR patients were older (75.11 ± 7.17 vs 69.79 ± 10.24; p=0.001). There was no statistical difference in gender, hypertension, COPD, CAD, or diabetes. GFR was significantly higher in OR patients (71.4 ± 31.09 vs. 53.68 ± 25.73). Postoperative dialysis was required more frequently in EVAR patients: 11% vs. 2% (p = 0.099). In the OR group, adjusted cumulative survival was 70.4% (61.1, 81.1) at 30 days, 47.0% (37.1, 59.6) at one year and 38.3% (28.6, 51.3) at 5 years. In the EVAR group the corresponding numbers were 77.0% (67.7, 87.5), 67.5% (57.0, 80.0) and 41.7% (30.4, 57.4), respectively. CONCLUSION: There is evidence for EVAR patients exhibiting a benefit in one-year survival, while patients treated with OR may have more favorable long-term survival given they survive for at least one year. Herein we provide a statistically rigorous comparison of OR and EVAR in short and long-term outcomes with up to 15 years of follow-up.

Does the choice of intraoperative fluid modify abdominal aneurysm repair outcomes?: A cohort analysis.

Intraoperatively administered hydroxyethyl starch could be a risk indicator for postoperative acute kidney injury (AKI) in vascular surgical patients.In a single-center retrospective cohort analysis, we assessed the impact of hydroxyethyl starch and other risk indicators on AKI and mortality in 1095 patients undergoing elective open abdominal aneurysm repair (AAA-OR) or endovascular aortic repair (EVAR). We established logistic regression models to determine the effect of various risk indicators, including hydroxyethyl starch, on AKI, as well as Cox proportional hazard models to assess the effect on mortality.The use of intravenous hydroxyethyl starch was not associated with an increased risk of AKI or mortality. Patients undergoing EVAR were less likely to develop AKI (4% vs 18%). Multivariate risk indicators associated for AKI included suprarenal or pararenal aortic cross-clamp [odds ratio (OR), 4.44; 95% confidence interval (95% CI), 2.538-7.784; P < .001] and procedure length (OR, 1.005; 95% CI, 1.003-1.007; P < .001), and favored EVAR (OR, 0.351; 95% CI, 0.118-0.654; P < .01). Main multivariate risk indicators associated with mortality included patients needing an urgent procedure [hazard ratio (HR), 2.294; 95% CI, 1.541-3.413; P < .001], those with suprarenal or pararenal aortic cross-clamp (HR, 1.756; 95% CI, 1.247-2.472; P < .01), and patients undergoing EVAR (HR, 1.654; 95% CI, 1.292-2.118; P < .001).We found neither a benefit nor a negative effect of hydroxyethyl starch on the risk of AKI or mortality. Instead, other variables and comorbidities were found to be relevant for the development of postoperative AKI and survival. Nevertheless, clinicians should be aware of the high risk of postoperative AKI, particularly among those undergoing AAA-OR procedures.

Lower levels of Caveolin-1 and higher levels of endothelial nitric oxide synthase are observed in abdominal aortic aneurysm patients treated with simvastatin.

This study was undertaken to verify whether simvastatin modulates Cav-1/eNOS expression, and if this modulation is associated with changes in pro- and anti-inflammatory cytokine and Toll-like receptor 4 (TLR4) level in abdominal aortic aneurysm (AAA). It is a 1:2 case-control study of non-statin (n=12) and simvastatin-treated patients (n=24) who underwent open AAA repair. Simvastatin treatment decreased Cav-1 (p<0.05) and increased eNOS expression (p<0.01) in the AAA wall. These changes might be dose dependent. The changes in Cav-1 and eNOS were associated with a trend towards decreased IL-6 and IL-17 concentration (p>0.05) and increased IL-10 concentration (p=0.055); however, TLR4 expression was unaffected, suggesting that simvastatin influences Cav-1 and eNOS in the AAA wall by other mechanisms. Simvastatin may modulate Cav-1 and eNOS expression in the aneurysmal wall, indicating a potentially beneficial role for statins in AAA patients.

The complement dependent cytotoxicity (CDC) immune effector mechanism contributes to anti-CD154 induced immunosuppression.

BACKGROUND: In many situations, anti-CD154 (CD40 ligand) monoclonal antibody (mAb) treatment is very potent in producing allograft tolerance. In accordance to our previously reported results, combined donor specific transfusion (DST)3 plus anti-CD154 mAb (MR1) treatment enables the permanent engraftment of DBA/2 (H-2(d)) islets into B6AF1 (H-2(b/kd)) recipients in all cases. It has been widely assumed that the MR1 anti-154 is a noncytolytic neutralizing mAb, and it exerts immune suppressive effects by blockade of CD40/CD154 signal pathway. In this study, we sought to test the role of complement dependent cytotoxicity (CDC) immune effector mechanism in MR1 anti-CD154 induced immunosuppression. METHODS: We have evaluated the contributions of CDC in the context of the potent tolerizing effects of DST plus anti-CD154 mAb treatment regiment in recipients of islet allografts. We have used CD40 knockout (KO) mice and complement C5 deficient mice DBA/2 as islet allograft recipients as well as cobra venom factor (CVF), a complement blocker, treatment. RESULTS: The absence of direct and indirect CD40/CD154 pathway signals does not prevent islet allograft acute rejection. Interestingly, MR1 anti-CD154 induces islet allograft tolerance in the absence of CD40/CD154 pathway. In a wild-type major histocompatibility complex (MHC) mismatched strain combination, DST results in accelerated islet allograft rejection. Combination of DST and MR1 anti-CD154 treatment prevents presensitization and permits permanent engraftment. However, administration of CVF abolishes the tolerance induction. Moreover, DST plus MR1 anti-CD154 regiment, a potent tolerizing therapy, does not prevent acute islet allograft rejection when complement C5 deficient DBA/2 mice are used as recipients. Thus, the mechanisms of the tolerizing effects by MR1 anti-CD154 are not limited to blockade of CD40/CD154 signals. The CDC immune effector mechanism contributes to MR1 anti-CD154 induced immunosuppression.

Osteoprotegerin and parathyroid hormone as markers of high-turnover osteodystrophy and decreased bone mineralization in hemodialysis patients.

Osteoprotegerin (OPG) has a profound inhibitory effect on osteoclast differentiation and bone resorption. Because high-turnover renal osteodystrophy (ROD) is characterized by increased osteoclast activity, serum OPG concentrations might be used to distinguish between forms of ROD. Twenty-six patients on maintenance hemodialysis therapy underwent a transiliac crest biopsy for evaluation of histopathologic characteristics and histomorphometric studies. ROD was diagnosed as type II (normal or low turnover) or type III (high turnover plus osteoidosis) disease. Bone mineralization density distribution (BMDD) was characterized by measuring the mean trabecular calcium concentration in the biopsy specimen with quantitative backscattered electron imaging. Patients underwent additional dual-energy x-ray absorptiometry (DEXA) of the spine and hip and measurement of such biochemical markers of bone turnover as OPG, intact parathyroid hormone (iPTH), osteocalcin, calcitonin, bone alkaline phosphatase, and cross-laps. OPG levels were significantly reduced in patients with ROD III compared with ROD II (118 +/- 38 versus 204 +/- 130 pg/mL; P < 0.05) and correlated with BMDD (r = 0.43; P < 0.05). Patients with ROD III showed significantly lower BMDD compared with healthy controls (21.42% +/- 0.12% versus 22.17% +/- 0.81% weight; P < 0.01). Besides iPTH, which showed significantly greater levels in patients with ROD III than ROD II (382 +/- 322 versus 136 +/- 156 pg/mL; P < 0.05), none of the serological markers or DEXA was useful in separation of the groups. Discriminant function analysis showed that a combination of OPG and iPTH correctly classifies ROD II in 72% and ROD III in 88% of patients. We conclude that OPG in combination with iPTH can be used as a marker for noninvasive diagnosis of ROD in hemodialysis patients. Furthermore, OPG serum levels might be used to estimate trabecular bone mineralization in these subjects.

Anticoagulation with prostaglandins and unfractionated heparin during continuous venovenous haemofiltration: a randomized controlled trial.

BACKGROUND: The objective of this prospective, randomized, controlled clinical study was to compare efficacy, safety, and costs of fixed-dose prostaglandins with adjusted-dose unfractionated heparin as anticoagulants for continuous venovenous haemofiltration. PATIENTS AND METHODS: Perioperative critically ill patients requiring continuous haemofiltration for acute renal failure received unfractionated heparin anticoagulation titrated to achieve an activated clotting time in the extracorporeal system of > 120 s. Patients were randomly assigned to receive a test infusion containing either prostaglandin I2 (5 ng/kg/min; group I; n = 15; 75 filters), prostaglandin E1 (5 ng/kg/min; group E; n = 18; 72 filters), or placebo (group H; n = 17; 63 filters). Heparin and test solutions were infused into the extracorporeal circuit before the haemofilter. All AN69-surface hollow fiber filters were primed with normal saline containing 5.000 IU heparin. RESULTS: The primary outcome measure--adequate haemofilter life span > 24 h--was compared by using Cochran's Q test. There was a significant difference in the frequencies of adequate haemofilter life span between the groups (36% group H, 65% group I, 59% group E; P < 0.05 versus group H). There were 6 bleeding episodes in group H, 2 in group E, and only 1 trivial bleeding episode in group I (P < 0.05 versus group H). Daily costs of haemofiltration were 61% higher in group I and 23% higher in group E than in group H (P < 0.05 versus group H). A heparin-sparing effect of prostaglandins was observed. CONCLUSIONS: Fixed-dose prostaglandins I2 and E1 reduced the incidence of haemofilter failure and bleeding when compared with adjusted-dose unfractionated heparin. There was no significant difference between the two prostaglandin groups. The increase in daily costs for haemofiltration treatment under prostaglandins is not clinically relevant.