[Recommendations for the specialist further training of nursing personnel on intensive care units in the treatment of abdominal aortic aneurysms: results of a modified Delphi procedure with experts]. / Empfehlungen zur Fachweiterbildung von Pflegefachpersonen der Intensivstation bei der Behandlung des Bauchaortenaneurysmas: Ergebnisse eines modifizierten Delphi-Verfahrens mit Expert:innen.

INTRODUCTION: The medical development in the previous 15 years and the changes in treatment reality of the comprehensive elective treatment of abdominal aortic aneurysms necessitate a re-evaluation of the quality assurance guidelines of the Federal Joint Committee in Germany (QBAA-RL). In the current version this requires a specialist further training quota for nursing personnel in intensive care wards of 50%. The quota was determined in 2008 based on expert opinions, although a direct empirical evidence base for this does not exist. METHODS: Representatives from the fields of patient representation, physicians, nursing personnel and other relevant interface areas were invited to participate in a modified Delphi procedure. Following a comprehensive narrative literature search, a survey and focus group discussions with national and international experts, a total of three anonymized online-based voting rounds were carried out for which previously determined key statements were assessed with a 4­point Likert scale (totally disagree up to totally agree). In addition, the expert panel had also defined a recommendation for a minimum quota for the specialist training of nursing personnel on intensive care wards in the treatment of abdominal aortic aneurysms, whereby an a priori agreement of 80% of the participants was defined as the consensus limit. RESULTS: Overall, 37 experts participated in the discussions and three successive voting rounds (participation rate 89%). The panel confirmed the necessity of a re-evaluation of the guideline recommendations and recommended the introduction of a shift-related minimum quota of 30% of the full-time equivalent of nursing personnel on intensive care wards and the introduction of structured promotional programs for long-term elevation of the quota. CONCLUSION: In this national Delphi procedure with medical and nursing experts as well as representatives of patients, the fundamental benefits and needs of professional specialist qualifications in the field of intensive care medicine were confirmed. The corresponding minimum quota for specialist further training of intensive care nursing personnel should generally apply without limitations to specific groups. The expert panel stipulates a shift-related minimum quota for intensive care nursing personnel with specialist training of 30% of the nursing personnel on intensive care wards and the obligatory introduction of structured and transparent promotion programs for the long-term enhancement.

Editor's Choice - Long Term Outcomes After Invasive Treatment of Carotid Artery Stenosis: a Longitudinal Study of German Health Insurance Claims.

OBJECTIVE: There is a paucity of observational data including long term outcomes after invasive treatment for carotid artery stenosis. METHODS: This retrospective study used nationwide insurance claims from the third largest provider in Germany, DAK-Gesundheit. Patients who underwent inpatient carotid endarterectomy (CEA) or carotid artery stenting (CAS) between 1 January 2008 and 31 May 2017 were included. The Elixhauser comorbidity scores from longitudinally linked hospital episodes were used. Kaplan-Meier analysis and the log rank test were used to determine long term stroke free survival. Multivariable regression models were developed to adjust for confounding. RESULTS: A total of 22 637 individual patients (41.6% female, median age 72.5 years) were included, of whom 15 005 (66.3%) were asymptomatic and 17 955 (79.3%) underwent CEA. After a median of 48 months, 5 504 any stroke or death events were registered. The mortality rate varied between 0.4% (CEA for asymptomatic stenosis) and 2.1% (urgent CAS for acute stroke patients) at 30 days, and between 4.1% and 8.4% at one year, respectively. The rate for any stroke varied between 0.6% (CEA for asymptomatic stenosis) and 2.5% (CAS for symptomatic patients) at 30 days, and between 2.5% and 6.4% at one year, respectively. The combined rate for any stroke and mortality at one year was 6.3% (CEA for asymptomatic stenosis), 8.7% (CAS for asymptomatic stenosis), and 12.5% (urgent CAS for acute stroke patients). After five years, the overall stroke rate was 7.4% after CEA and 9.0% after CAS. In adjusted analyses, both older age and van Walraven comorbidity score were associated with events, while treatment of asymptomatic stenosis was associated with lower event rates. CONCLUSION: The current study revealed striking differences between previous landmark trials and real world practice. It further suggested excess deaths among invasively treated asymptomatic patients.

Bridging vascular physiology to vascular medicine: an integrative laboratory class.

Vascular diseases of the legs are highly prevalent and constitute an important part of medical curricula. The understanding of these diseases relies on strongly interwoven aspects of vascular physiology and vascular medicine. We aimed to connect these within a horizontally integrated laboratory class on vascular physiology of the leg that was designed in cooperation between the departments of physiology and vascular surgery. Conceptually, we applied examination techniques of vascular medicine to visualize physiological parameters that are altered by the most frequent diseases. This facilitates integrative discussions on malfunctions, trains diagnostic skills, and bridges to vascular medicine. In four experiments, we use oscillometry and impedance venous occlusion plethysmography to address key aspects of the arterial and venous system of the legs: 1) arterial pulse wave, 2) arterial systolic blood pressure, 3) venous capacitance and venous outflow, and 4) reactive hyperemia. After the experiments, physiological vascular function, the associated diseases, their impact on the recorded parameters, and diagnostic options are discussed. To allow reproduction, we describe the course structure and the experimental setup in detail. We present the experimental data of a cohort of medical students and document learning success and student satisfaction. All experiments were feasible and provided robust data on physiologically and clinically relevant vascular functions. The activity was perceived positively by the students and led to a substantial improvement of knowledge. With this work, we offer a template for reproduction or variation of a proven concept of horizontally integrated teaching of vascular physiology of the leg.NEW & NOTEWORTHY This article presents an integrative laboratory class on vascular physiology bridging to vascular medicine. The four experiments rely on oscillometry and venous occlusion plethysmography. We describe in detail this new class regarding structure, experimental setup, and experimental procedure, and we give insight into the applied materials. Moreover, we present the experimental data of 74 students and a quantitative evaluation of the students' learning success and acceptance.

Experimental Atherosclerosis Research on Large and Small Animal Models in Vascular Surgery.

Animal models have significantly advanced our understanding of the mechanisms of atherosclerosis formation and the evaluation of therapeutic options. The current focus of research is on preventive strategies and includes pharmacologic and biologic interventions directed primarily against smooth-muscle cell proliferation, endovascular devices for recanalization and/or drug delivery, and an integrated approach using both devices and pharmacobiologic agents. The experience over many decades with animal models in vascular research has established that a single, ideal, naturally available model for atherosclerosis does not exist. The spectrum ranges from large animals such as pigs to small animal experiments with genetically modified rodents such as the ApoE-/- mouse with correspondingly differently pronounced changes in their lipid and lipoprotein levels. The development of transgenic variants of currently available models, e.g., an ApoE-deficient rabbit line, has widened our options. Nevertheless, an appreciation of the individual features of natural or stimulated disease in each species is of importance for the proper design and execution of relevant experiments.

Intrinsic functional brain connectivity is resilient to chronic hypoperfusion caused by unilateral carotid artery stenosis.

INTRODUCTION: Chronic cerebral hypoperfusion caused by asymptomatic high-grade stenosis of the internal carotid artery (ICA) has been associated with impaired cognitive function. Only few studies exist on underlying changes of functional connectivity (FC). METHODS: 20 patients with unilateral high-grade ICA stenosis without MRI lesions and 25 aged-match controls underwent resting-state functional MRI (rsfMRI) and neuropsychological assessment. Patients were examined within ten days before and 6-10 weeks after surgical or interventional revascularization of carotid stenosis. We examined mean resting-state FC ipsi- and contralateral to stenosis and network topology using graph-theoretical measures. RESULTS: At baseline, intrahemispheric FC was similar for patients and healthy controls. After revascularization mean FC increased moderately without an effect on network topology. Patients performed worse in TMT B and Stroop test, while performance in global screening tests for dementia (Mini Mental Status Examination, DemTect) were comparable. Test results did not improve after revascularization. CONCLUSION: In our study population, we find no effect of chronic hypoperfusion on FC and global cognitive function, although we observe minor impairments in processing speed and mental flexibility. The subtle increase of FC after revascularization could indicate excessive upregulation after restoration of perfusion. However, it might as well be a coincidental finding due to the limited sample size.

Incidence, predictors, and outcomes of spinal cord ischemia in elective complex endovascular aortic repair: An analysis of health insurance claims.

OBJECTIVE: This study aimed to determine predictors and outcomes associated with spinal cord ischemia (SCI) after elective fenestrated or branched endovascular aneurysm repair (F/BEVAR) of thoracoabdominal aortic aneurysm (TAAA), abdominal aortic aneurysm (AAA), or aortic dissection. METHODS: Health insurance claims data of Germany's third largest insurance provider, DAK-Gesundheit, were used to investigate SCI in elective F/BEVAR performed between 2008 and 2017. The International Classification of Diseases and German Operation and Procedure Classification System were used. We stratified the results into F/BEVAR with one or two (AAA) vs three or more (TAAA) fenestrations or branches. RESULTS: A total of 877 patients (18.9% female; 5.8% with SCI) matching the inclusion criteria were identified during the study period. SCI occurred more often after F/BEVAR of TAAA vs AAA (10.7% vs 3.0%; P < .001). SCI was associated with female sex in the AAA group (odds ratio, 3.87; 95% confidence interval [CI], 1.25-11.15; P = .014) and with cardiac arrhythmias in the TAAA group (odds ratio, 2.98; 95% CI, 1.24-7.06; P = .013). Compared with patients without SCI, SCI patients were more likely to suffer from drug use disorders (eg, opioids, cannabinoids, sedatives) in the TAAA group (17.6% vs 2.1%; P < .05). After F/BEVAR of TAAA, the occurrence of SCI was associated with higher 90-day mortality (14.7% vs 1.1%; P < .05), longer postoperative hospital stay (22 vs 9 days; P < .05), and severe adverse events, such as acute respiratory insufficiency (44.1% vs 12.7%), acute renal failure (35.3% vs 11.3%), and pneumonia (29.4% vs 4.9%; all P < .05). In adjusted analyses, SCI was associated with worse long-term survival after F/BEVAR for TAAA (hazard ratio, 2.54; 95% CI, 1.37-4.73; P < .003). CONCLUSIONS: Female AAA patients and TAAA patients with cardiac arrhythmias are at highest risk for development of SCI after F/BEVAR. The occurrence of this event was strongly associated with higher major complication rates and worse short-term and long-term survival. This emphasizes a need to further illuminate the value of spinal cord protection protocols in F/BEVAR.

Determinants of Serum- and Plasma Sphingosine-1-Phosphate Concentrations in a Healthy Study Group.

Introduction To correctly interpret plasma- or serum-sphingosine-1-phosphate (S1P) concentrations measured in clinical studies it is critical to understand all major determinants in healthy controls. Methods Serum- and plasma-S1P from 174 healthy blood donors was measured by liquid chromatography-tandem mass spectrometry and correlated to clinical laboratory data. Selected plasma samples, 10 with high and 10 with low S1P concentrations, were fractionated into very low-density lipoprotein (VLDL)-, low density lipoprotein (LDL)-, high density lipoprotein (HDL)-, and lipoprotein-free fractions. S1P was then measured in each fraction to determine its distribution. Results The mean S1P concentration in serum (1.04 ± 0.24 nmol/mL) was found 39% higher compared with plasma (0.75 ± 0.16 nmol/mL) and overall was not different between men and women. Only when stratified for age and gender, older women were found to exhibit higher circulatory S1P levels than men. In plasma, S1P levels correlate to red blood cell (RBC) counts but not to platelet counts. Conversely, serum-S1P correlates to platelet counts but not to RBC counts. In addition, eosinophil counts are strongly associated with serum-S1P concentrations. Both serum- and plasma-S1P correlate to total cholesterol but not to HDL-C. The distribution of S1P between VLDL-, LDL-, HDL-, and lipoprotein-free fractions is independent of total plasma-S1P concentrations. S1P concentrations in HDL but not in LDL are highly variable. Conclusion These data indicate S1P concentrations in plasma and serum to be differentially associated with cell counts and S1P carrier proteins. Besides platelets, eosinophil counts are identified as a novel determinant for serum-S1P concentrations further suggesting a role for S1P in eosinophil pathologies.

Editor's Choice - Long Term Survival after Femoropopliteal Artery Revascularisation with Paclitaxel Coated Devices: A Propensity Score Matched Cohort Analysis.

OBJECTIVE: The aim of this study was to determine the survival of patients after use of paclitaxel coated devices (PCX), as a recent meta-analysis of randomised trials reported higher mortality in patients treated with PCX balloons and stents METHODS: A retrospective health insurance claims analysis of patients covered by the second largest insurance fund in Germany, BARMER, was used to identify index femoropopliteal arterial interventions between 1 January 2010 and 31 December 2018. To ensure first PCX exposure, patients with prior deployment of PCX were excluded. The study cohort was stratified into patients with chronic limb threatening ischaemia (CLTI) and intermittent claudication (IC), then into balloons vs. stents cohorts. Within each stratum PCX were compared with uncoated devices. Propensity score matching was used to balance the study groups. Survival was evaluated using the Kaplan-Meier method and Cox regression. RESULTS: There were 37 914 patients (mean age 73.3 years; 48.8% female) included in the study. The annual proportion of PCX use increased from 3% to 39% during the study period for CLTI and from 4% to 48% for IC (both p < .001). Paclitaxel coated balloons and stents were associated with improved overall survival (hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.77-0.90), amputation free survival (HR 0.85, 95% CI 0.78-0.91), and freedom from major cardiovascular events (HR 0.82, 95% CI 0.77-0.89) vs. uncoated devices at five years for CLTI. In IC cohort, mortality was significantly lower after using drug coated balloons (DCB) (HR 0.87, 95% CI 0.76-0.99) or combined DCB and drug eluting stents (HR 0.88, 95% CI 0.80-0.98). CONCLUSION: In this large health insurance claims analysis, rapid adoption of PCX, higher long term survival, better amputation free survival, and lower rates of major cardiovascular events were seen after their use for the treatment of CLTI.

Ten Years of Urgent Care of Ruptured Abdominal Aortic Aneurysms in a High-Volume-Center.

BACKGROUND: The urgent treatment of ruptured abdominal aortic aneurysms (rAAA) remains a challenging condition with devastating morbidity and mortality. Available studies are often limited due to a significant selection bias. This study aims to illuminate real-world evidence using comprehensive data from electronic health records, registries, postmortem findings, and administrative data on all consecutively treated patients presenting with rAAA at a tertiary care center. METHODS: This is a retrospective cross-sectional cohort study covering consecutively treated patients with rAAA between 2009 and 2018. All noninvasive treatments, fatalities, and invasive repairs were included. Information on patient's characteristics, prehospital, and inpatient care was gathered. Short-term outcomes and long-term survival were analyzed for relevant subgroups. RESULTS: In total, 139 patients with rAAA (median age 75 years and 20.9% females, 79.9% infrarenal) were treated increasingly frequent by endovascular aortic repair (EVAR) when compared to open-surgical aortic repair (OSR) during the study period (16.7% in 2009 to 33.3% in 2018, P < 0.05). The rate of patients who had been turned down for rAAA repair was 10.8%, and the overall in-hospital mortality was 43.2%. Perioperative morbidity and mortality were similar for EVAR and OSR, although patients treated by OSR presented with a lower mean Glasgow Coma Scale during the prehospital (12.7 vs. 14.3) and inpatient care (12.7 vs. 14.4) (both P < 0.001), higher rates of intubation (12.8% vs. 10.9%, P < 0.001), lower systolic blood pressure (115 mm Hg vs. 127 mm Hg, P = 0.042), and more often had a cardiac arrest before the operation (14.1% vs. 2.3%, P < 0.001). Higher patient's age (Odds Ratio, OR 1.09; Hazard Ratio, HR 1.06), history of stroke or transient ischemic attack (OR 5.30; HR 2.64), higher serum creatinine (OR 1.81; HR 1.31), and occurrence of colonic ischemia (OR 11.31; HR 2.82) were significantly associated with higher odds of dying in hospital and in the longer term, respectively. CONCLUSIONS: We observed comparable outcomes following OSR and EVAR, although hemodynamically unstable patients were more likely to be treated by OSR. This study also confirmed the impact of colonic ischemia as a devastating complication following rAAA repair emphasizing the need for further reflection by the vascular community.

Cervical Debranching in the Endovascular Era: A Single Centre Experience.

OBJECTIVE/BACKGROUND: Debranching of the supra-aortic arteries is a common practice either as part of a hybrid treatment of aortic arch pathology or owing to arterial occlusive disease. Results of the debranching techniques have not been reported frequently. METHODS: This was a retrospective single centre study of all consecutive patients with cervical debranching procedures as part of hybrid aortic arch repair. RESULTS: Between 2010 and 2017, 201 patients underwent 211 cervical debranching procedures in a tertiary centre. Mean ± SD patient age was 67.7 ± 10.7 years (70.6% males; n = 142/201) and mean ± SD body mass index (BMI) was 26.3 ± 5. In 78.7% of the cases carotid-subclavian bypass was performed alone (n = 166/211) followed by transposition of the subclavian artery to the ipsilateral carotid (n = 17/211; 8.1%) and in 28 cases (13.3%) a combination of procedures was performed. Twenty-four cases (11.4%) were complicated with local bleeding and 21 cases required re-intervention (10.4%). Nineteen patients (9.5%) developed local peripheral neurological damage post-operatively. Eight patients (3.8%) developed a chylous fistula and five (2.4%) presented with a local wound infection. One patient (0.5%) developed a bypass graft infection. The thirty day mortality was 7.6% (n = 16/211): one death occurred after isolated debranching without thoracic endovascular aneurysm repair (TEVAR; 0.5%). Whether the hybrid procedures were undertaken in a single stage (simultaneous TEVAR and cervical debranching) or two stage fashion appeared to have a significant impact on 30 day mortality (single stage n = 9/60 [15%] vs. debranching alone or two stage hybrid procedures n = 7/144 [4.9%]; p = .018). The major stroke incidence was 4.3% (n = 9/211); no strokes occurred after isolated debranching. Stroke was correlated with longer operating times (odds ratio [OR] 1.006; 95% confidence interval [CI] 1.000-1.011; p = .045) and higher BMI (OR 1.195; 95% CI 1.009-1.415; p = .039). Mean ± SD follow up was 15 ± 17 months (range 0-89 months). Primary cumulative graft patency during follow up was 98.1% (n = 207/211) and secondary patency was 100%. CONCLUSION: The results of cervical debranching procedures showed not only excellent patency rates, but also a significant rate of local complications. Carotid-subclavian bypass appeared to be safer with significantly fewer post-operative complications. Staged hybrid procedures also seemed to be safer.

Cortical thickness and cognitive performance in asymptomatic unilateral carotid artery stenosis.

BACKGROUND: We investigated changes of cortical thickness and its association with cognitive performance in patients with high-grade carotid artery stenosis without ischemic brain lesions. METHODS: We studied 25 patients with unilateral carotid artery stenosis ≥50% and 25 age-matched controls. All subjects underwent T1-weighted MRI, and cortical thickness was measured in 33 regions of interest in each hemisphere, as well as in brain regions belonging to the vascular territory of the middle cerebral artery (MCA). General linear mixed models were fitted to the dependent variable cortical thickness. Cognitive assessment comprised the Stroop Test and Trail Making Test B. RESULTS: In the linear mixed model, presence of carotid stenosis had no effect on cortical thickness. There was a significant interaction of stenosis and region with a trend towards lower cortical thickness in the MCA region on the side of carotid stenosis. Patients with carotid stenosis performed significantly worse on the Stroop test than controls, but there was no correlation with cortical thickness. CONCLUSION: In patients with carotid stenosis without ischemic brain lesions, neither a clear pattern of reduced cortical thickness nor an association of cortical thickness with cognitive function was observed. Our data do not support the hypothesized association of cortical thinning and cognitive impairment in carotid stenosis.

Dynamics of brain perfusion and cognitive performance in revascularization of carotid artery stenosis.

INTRODUCTION: There is evidence suggesting a detrimental effect of asymptomatic carotid artery stenosis on cognitive function even in the absence of ischemic cerebral lesions. Hypoperfusion has been suggested as pathophysiological mechanism causing cognitive impairment. We aimed to assess cognitive performance and cerebral perfusion changes in patients with carotid artery stenosis without ischemic lesions by arterial spin labeling (ASL) and contrast enhanced (CE) perfusion MRI before and after revascularization therapy. METHODS: 17 asymptomatic patients with unilateral high-grade (≥70%) carotid artery stenosis without evidence of structural brain lesions underwent ASL and CE perfusion MRI and cognitive testing (MMSE, DemTect, Clock-Drawing Test, Trail-Making Test, Stroop Test) before and 6-8 weeks after revascularization therapy by endarterectomy or stenting. Multiparametric perfusion maps (ASL: cerebral blood flow (ASL-CBF), bolus arrival time (ASL-BAT); CE: cerebral blood flow (CE-CBF), mean transit time (CE-MTT), cerebral blood volume (CE-CBV)) were calculated and analyzed by vascular territory. Relative perfusion values were calculated. RESULTS: Multivariate analysis revealed a significant impact of revascularization therapy on all perfusion measures analyzed. At baseline post-hoc testing showed significant hypoperfusion in MCA borderzones as assessed by ASL-CBF, ASL-BAT, CE-MTT and CE-CBV. All perfusion alterations normalized after revascularization. We did not observe any significant correlation of cognitive test results with perfusion parameters. There was no significant change in cognitive performance after revascularization. CONCLUSION: We found evidence of traceable perfusion alterations in patients with high grade carotid artery stenosis in the absence of structural brain lesions, which proved fully reversible after revascularization therapy. In this cohort of asymptomatic patients we did not observe an association of hypoperfusion with cognitive performance.

Gender disparities in fenestrated and branched endovascular aortic repair.

OBJECTIVES: Gender disparities in risk factors and outcomes following aortic repair are important issues in healthcare. To date, no large-scale multicentre study addresses this topic in complex endovascular aortic repair. We aimed to determine the outcomes following fenestrated or branched endovascular aortic repair of aneurysms and dissections in female and male patients. METHODS: Health insurance claims data of Germany's third largest insurance provider, DAK-Gesundheit, were used to investigate gender disparities in elective fenestrated or branched endovascular aortic repair of thoraco-abdominal or abdominal aortic aneurysms or dissections performed between 2008 and 2017. Elixhauser comorbidities and the linear van Walraven score were used to adjust for confounders in the multivariable analyses. RESULTS: There were 959 patients in the cohort, in whom 163 (17%) were female. The mean age was 73 ± 8 years with no differences between females and males. No gender disparities were observed regarding the van Walraven comorbidity score (6.9 vs 6.8, P = 0.83), but complications occurred more frequently in females. Acute renal failure (relative risk 1.71, 95% confidence interval 1.06-2.77), paraplegia (relative risk 2.71, 95% confidence interval 1.28-5.77) and bleeding or anaemia requiring transfusion (relative risk 1.76, 95% confidence interval 1.39-2.22) were more common in women. In multivariable models, female patients were at a higher risk of in-hospital death (odds ratio 3.206, P < 0.001). Consequently, female gender was associated with lower long-term survival (hazard ratio 1.506, P = 0.006). CONCLUSIONS: In complex endovascular aortic repair, females are more likely to experience complications and have worse in-hospital and, consequently, long-term survival when compared to males. Future studies should include anatomic parameters to determine the impact of anatomy on outcome disparities.

Incidence, Predictors, and Outcomes of Colonic Ischaemia in Abdominal Aortic Aneurysm Repair.

OBJECTIVE/BACKGROUND: Colonic ischaemia (CI) is a severe complication following abdominal aortic aneurysm (AAA) repair, leading to high morbidity and mortality. The aim of the study was to determine the incidence, predictors, and outcomes of CI following AAA repair. METHODS: National claims from Germany's third largest insurance provider, DAK-Gesundheit, were used to investigate CI after intact (iAAA) and ruptured (rAAA) AAA repairs. Patients undergoing endovascular (EVAR) or open surgical (OSR) repairs between January 2008 and December 2017 were included in the study. RESULTS: There were 9145 patients (8248 iAAA and 897 rAAA) undergoing EVAR or OSR procedures and the median follow up was 2.28 years. Most patients were male (79.2% iAAA, 79.3% rAAA); the median age was 73.0 years (iAAA group) and 76.0 years (rAAA group). Overall, CI occurred 97 (1.2%) times after iAAA and 95 (10.6%) after rAAA. In univariable analyses CI occurred less often after EVAR than after OSR (0.6% vs. 3.7%; p < .001). Acute post-operative renal and respiratory insufficiencies were also related to the occurrence of CI (p < .001). CI was associated with greater in hospital mortality (42.2% vs. 2.7% for iAAA, 64.2% vs. 36.3% for rAAA; p < .001) and lower long-term survival for iAAA (Kaplan-Meier analysis). In multivariable analyses, rAAA (odds ratio [OR] 5.59), and higher van Walraven comorbidity score (OR 1.09) were independently associated with greater risk of CI occurrence. EVAR use (OR 0.30) was protective. EVAR use remained protective in stratified analyses within iAAA (OR 0.32) and rAAA (OR 0.26). CONCLUSION: Post-operative CI after AAA repair is not common but is associated with worse in hospital outcomes and lower long-term survival. EVAR was protective after both rAAA and iAAA repairs. When discussing the treatment of AAA with patients the protective effect of EVAR should be considered. Future studies should validate predictive scores and advance preventive strategies.

Sphingosine-1-phosphate receptor 1 regulates neointimal growth in a humanized model for restenosis.

OBJECTIVE: The main objective of this study was to define a role of sphingosine-1-phosphate receptor 1 (S1PR1) in the arterial injury response of a human artery. The hypotheses were tested that injury induces an expansion of S1PR1-positive cells and that these cells accumulate toward the lumen because they follow the sphingosine-1-phosphate gradient from arterial wall tissue (low) to plasma (high). METHODS: A humanized rat model was used in which denuded human internal mammary artery (IMA) was implanted into the position of the abdominal aorta of immunosuppressed Rowett nude rats. This injury model is characterized by medial as well as intimal hyperplasia, whereby intimal cells are of human origin. At 7, 14, and 28 days after implantation, grafts were harvested and processed for fluorescent immunostaining for S1PR1 and smooth muscle α-actin. Nuclei were stained with 4',6-diamidine-2'-phenylindole dihydrochloride. Using digitally reconstructed, complete cross sections of grafts, intimal and medial areas were measured, whereby the medial area had virtually been divided into an outer (toward adventitia) and inner (toward lumen) layer. The fraction of S1PR1-positive cells was determined in each layer by counting S1PR1-positive and S1PR1-negative cells. RESULTS: The fraction of S1PR1-postive cells in naive IMA is 58.9% ± 6.0% (mean ± standard deviation). At day 28 after implantation, 81.6% ± 4.4% of medial cells were scored S1PR1 positive (P < .01). At day 14, the ratio between S1PR1-positive and S1PR1-negative cells was significantly higher in the lumen-oriented inner layer (9.3 ± 2.1 vs 6.0 ± 1.0; P < .01). Cells appearing in the intima at day 7 and day 14 were almost all S1PR1 positive. At day 28, however, about one-third of intimal cells were scored S1PR1 negative. CONCLUSIONS: From these data, we conclude that denudation of IMA specifically induces the expansion of S1PR1-positive cells. Based on the nonrandom distribution of S1PR1-positive cells, we consider the possibility that much like lymphocytes, S1PR1-positive smooth muscle cells also use S1PR1 to recognize the sphingosine-1-phosphate gradient from tissue (low) to plasma (high) and so migrate out of the media toward the intima of the injured IMA.