[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]

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 4‑point 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.

Aortic Vascular Graft and Endograft Infection-Patient Outcome Cannot Be Determined Based on Pre-Operative Characteristics

Vascular graft/endograft infection (VGEI) is a serious complication after aortic surgery. This study investigates VGEI and patient characteristics, PET/CT quantification before surgical or conservative management of VGEI and post-intervention outcomes in order to identify patients who might benefit from such a procedure. PET standard uptake values (SUV) were quantitatively assessed and compared to a non-VGEI cohort. The primary endpoints were in-hospital mortality and aortic reintervention-free survival at six months. Ninety-three patients (75% male, 65 ± 10 years, 82% operated) were included. The initial operation was mainly for aneurysm (67.7%: 31% EVAR, 12% TEVAR, 57% open aortic repair). Thirty-two patients presented with fistulae. PET SUVTLR (target-to-liver ratio) showed 94% sensitivity and 89% specificity. Replacement included silver-coated Dacron (21.3%), pericardium (61.3%) and femoral vein (17.3%), yet the material did not influence the overall survival (p = 0.745). In-hospital mortality did not differ between operative and conservative treatment (19.7% vs. 17.6%, p = 0.84). At six months, 50% of the operated cohort survived without aortic reintervention. Short- and midterm morbidity and mortality remained high after aortic graft removal. Neither preoperative characteristics nor the material used for reconstruction influenced the overall survival, and, with limitations, both the in-hospital and midterm survival were similar between the surgically and conservatively managed patients.

Endovascular aortic repair with sac embolization for the prevention of type II endoleaks (the EVAR-SE study): study protocol for a randomized controlled multicentre study in Germany

BACKGROUND

Beyond a certain threshold diameter, abdominal aortic aneurysms (AAA) are to be treated by open surgical or endovascular aortic aneurysm repair (EVAR). In a quarter of patients who undergo EVAR, inversion of blood flow in the inferior mesenteric artery or lumbar arteries may lead to type II endoleak (T2EL), which is associated with complications (e.g. AAA growth, secondary type I endoleak, rupture). As secondary interventions to treat T2EL often fail and may be highly invasive, prevention of T2EL is desirable. The present study aims to assess the efficacy of sac embolization (SE) with metal coils during EVAR to prevent T2EL in patients at high risk.

METHODS

Over a 24-month recruitment period, a total of 100 patients undergoing EVAR in four vascular centres (i.e. Klinikum rechts der Isar of the Technical University of Munich, University Hospital Augsburg, University Hospital Dresden, St. Joseph's Hospital Wiesbaden) are to be included in the present study. Patients at high risk for T2EL (i.e. ≥ 5 efferent vessels covered by endograft or aneurysmal thrombus volume <40%) are randomized to one group receiving standard EVAR and another group receiving EVAR with SE. Follow-up assessments postoperatively, after 30 days, and 6 months involve contrast-enhanced ultrasound scans (CEUS) and after 12 months an additional computed tomography angiography (CTA) scan. The presence of T2EL detected by CEUS or CTA after 12 months is the primary endpoint. Secondary endpoints comprise quality of life (quantified by the SF-36 questionnaire), reintervention rate, occurrence of type I/III endoleak, aortic rupture, death, alteration of aneurysm volume, or diameter. Standardized evaluation of CTA scans happens through a core lab. The study will be terminated after the final follow-up visit of the ultimate patient.

DISCUSSION

Although preexisting studies repeatedly indicated a beneficial effect of SE on T2EL rates after EVAR, patient relevant outcomes have not been assessed until now. The present study is the first randomized controlled multicentre study to assess the impact of SE on quality of life. Further unique features include employment of easily assessable high-risk criteria, a contemporary follow-up protocol, and approval to use any commercially available coil material. Overcoming limitations of previous studies might help SE to be implemented in daily practice and to enhance patient safety.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05665101. Registered on 23 December 2022.

Editor's Choice - Temporal fluctuations of hospital incidence and mortality of ruptured abdominal aortic aneurysms in Germany: A secondary data analysis of German hospital episode statistics 2009 - 2018

OBJECTIVE

Abdominal aortic aneurysm rupture (rAAA) is still associated with high mortality. Recent studies have shown higher incidences in autumn and winter, and worse outcomes after rAAA treatment on weekends in some countries. This study aimed to analyse seasonal, weekday, and daytime fluctuations of the hospital incidence, treatment modalities, and outcomes of rAAA, based on the most recent nationwide German real world data.

METHODS

A secondary data analysis of diagnosis related group statistics (2009 - 2018), obtained from the German Federal Statistical Office, was conducted. Cases encoded by a diagnosis of rAAA in conjunction with procedural codes for endovascular aortic repair (EVAR) or open aortic repair were included. Patient and procedural characteristics, comorbidities, and outcomes were analysed for seasonal (spring, summer, autumn, and winter), weekday (Monday - Sunday) and daytime (0:00 - 8:00, 8:00 -16:00, 16:00 -20:00, and 20:00 - 24:00) fluctuations by descriptive statistics and multivariable regression analyses.

RESULTS

Thirteen thousand and seventy patients (85% male, median age 75 years) were treated for rAAA. Endovascular aortic repair was associated with lower mortality (adjusted OR 0.40, 95% CI 0.37 - 0.44). While no significant seasonal fluctuations were found, on a weekday basis lower hospital incidences were found on Mondays (12%) and Sundays (11%) compared with other weekdays (15 - 16%). Similarly, EVAR rates were lower on Mondays and Sundays (25% and 24%, respectively) compared with other weekdays (30 - 33%). Multivariable analyses revealed higher mortality rates on Mondays and Sundays. On a daytime basis, lower EVAR rates and higher mortality rates were found during the 16:00 - 8:00 period.

CONCLUSION

In German hospitals, incidences and EVAR rates to treat rAAA were lowest on Mondays and Sundays. The associated overall mortality rates were highest on the respective days. Further restructuring and centralisation of AAA treatment in Germany could potentially mitigate this weekday effect.

Vascular e-Learning in the MENA Region during the COVID-19 Pandemic

<b><i>Introduction:</i></b> With the steady rise in interest in e-learning and the sudden boost provoked by the COVID-19 pandemic, it becomes necessary to explore the e-learning experience within the medical community in the MENA region. <b><i>Methods:</i></b> An online survey was conducted during the early phase of the COVID-19 pandemic (June 15 – October 15, 2020). <b><i>Results:</i></b> Seventy-eight vascular surgeons and trainees from 16 countries participated. 88% of the participants were male. 55% attended more than 4 activities. More than half of the activities did not lead to any official certification. Topic was the primary determinant for attending an activity. National societies and social media played a major role in disseminating activity-related information. Lack of time, increased workload, differences in time zone, and technical issues were the main obstacles cited. 84.7% of the participants had a positive impression. <b><i>Conclusion:</i></b> As the COVID-19 pandemic boosted e-learning activities in vascular surgery, a shift was observed in the learning mode and new leadership skills were called upon. Novel ways of quality control are required.

A prospective survey study on the education and awareness about walking exercise amongst inpatients with symptomatic peripheral arterial disease in Germany

Background: To determine the adherence to supervised exercise training and underlying reasons for non-adherence amongst patients with inpatient treatment of symptomatic lower extremity peripheral arterial disease (PAD). Patients: This was a prospective questionnaire-based survey study of all consecutively treated inpatients with treatment for either intermittent claudication or chronic limb-threatening ischaemia (CLTI) surveyed at sixteen participating centres in Germany. Results: A total of 235 patients (median age 70 years) were included, thereof 29.4% females and 34.6% with CLTI. The median time from first PAD diagnosis was 4 years (IQR: 1-8). Only 11.4% have previously participated in any walking exercise programme before the index treatment, thereby 10.0% in the IC subgroup and 12.0% with CLTI. Amongst all patients, 35.6% responded they were appropriately informed about the necessity and benefits of walking exercise programmes by their hospital physicians (25.8% by general practitioners), and 65.3% agreed that adherence to supervised exercise may improve their pain-free walking distance. A total of 24.5% responded they had access to necessary information concerning local walking exercise programmes. Amongst 127 free text comments on the reasons for non-adherence to supervised exercise training, 64% of the comments contained lack of information or consent on such measures. Conclusions: Less than 12% of the patients enrolled in the current study have ever participated in a walking exercise programme during their life course. Although all practice guidelines contain corresponding class I recommendations, especially for patients suffering from IC, most patients responded that they were not appropriately informed about the necessity of exercise training along with the fact that 65% agreed that exercise may increase the pain-free walking distance. Taken all together, these results emphasise that we miss an important opportunity in the patient-physician communication. Efforts should be made to improve acceptance and application of structured walking-exercise for patients with PAD.

External Validity of Randomised Controlled Trials on Carotid Revascularisation: Trial Populations May Not Always Reflect Patients in Clinical Practice

OBJECTIVE

The external validity of randomised controlled trials (RCTs) and their transferability to clinical practice is under investigated. This study aimed to analyse the exclusion criteria of recent carotid RCTs comparing carotid endarterectomy (CEA) and carotid artery stenting, and to assess the eligibility of consecutive clinical practice cohorts to those RCTs.

METHODS

An analysis of the clinical and anatomical exclusion criteria of RCTs for asymptomatic (SPACE-2, ACST-2, CREST-1, and CREST-2) and symptomatic carotid stenosis (SPACE-1, CREST-1, ICSS, and EVA-3S) was performed. Two hundred consecutive asymptomatic and 200 consecutive symptomatic patients, treated by CEA, or transfemoral or transcarotid artery stenting at a tertiary referral university centre were assessed for their potential eligibility for each corresponding RCT. RCT patient data were pooled and differences from the clinical practice cohort analysed. Statistics were descriptive and comparative using Fisher's exact and t tests.

RESULTS

The number of clinical and anatomical exclusion criteria differed widely between RCTs. Potential eligibility rates of the clinical practice cohort for RCTs with regard to asymptomatic carotid stenosis were 80.5% (ACST-2), 79.5% (SPACE-2), 47% (CREST-1), and 20% (CREST-2). For RCTs on symptomatic carotid stenosis the eligibility rates were 89% (ICSS), 86.5% (EVA-3S), 64% (SPACE-1), and 39% (CREST-1). Both clinical practice cohorts were older by about three years and patients were more often male vs. the RCTs. Furthermore, a history of smoking (asymptomatic patients), hypertension (symptomatic patients), and atrial fibrillation was diagnosed more often, whereas hypercholesterolaemia and coronary heart disease (asymptomatic patients) were less prevalent. More clinical practice patients were on antiplatelets, anticoagulants, and lipid lowering drugs. Symptomatic clinical practice patients presented more often with retinal ischaemia and less often with minor hemispheric strokes than patients in the RCTs.

CONCLUSION

The external validity of contemporary carotid RCTs varies considerably. Patients in routine clinical practice differ from RCT populations with respect to age, comorbidities, and medication. These data are of interest for clinicians and guideline authors and may be relevant for the design of future comparative trials.

Vascular education through e-Learning

Summary: Background: The COVID-19 pandemic has changed everyday life and work in many ways. As travelling to meetings and conferences was almost completely suppressed for most of healthcare professionals, e-Learning became increasingly prominent. The overall utility of e-Learning during the COVID-19 pandemic as well as its shortcomings in the international community of vascular surgery were assessed through the EL-COVID study. Regional variability was observed amongst participating nations, which is currently being addressed through several ongoing subgroup analyses. Our study completes the aforementioned efforts and aims to investigate the adherence and adoption of vascular e-Learning in Germany. Methods and participants: Using an online survey, EL-COVID gathered answers from 856 vascular surgeons, of whom 70 were located in Germany. We analyzed the answers of 62 German responders that attended at least one e-Learning activity and compared them with the remaining worldwide data. Results: Out of all European countries, Germany was best represented and ranked second worldwide after Mainland China (n=109). 30.6 percent of the German responders were female (vs. 20% worldwide; p=0.048) and 56.4% were vascular surgeons with >5 years of practice (vs. 56.3; p=0.975). The international cohort generally engaged in more e-Learning. Most German participants attended less than 4 online activities, while only 24.2% took part in more than 4 such events (vs. 56.3; p<0.0001). While the overall impression of e-Learning activities during the COVID-19 pandemic was positive, German employers were less supportive of participation during working hours (30.6% vs. 44%; p=0.042). The main reason for not attending was lack of time due to increased workload (56.5% vs. 50%; p=0.328). National and international societies played a lesser role in promoting such activities in Germany (22.6% vs. 39.2%; p=0.010), the same accounts for social media (16.1 vs. 30.3; p=0.017). Conclusions: E-Learning complements the classical training methods and has been embraced as a relevant alternative in the time of the COVID-19 pandemic. The results of this survey appeal to German employers and national societies to improve support and dissemination of e-Learning activities in the vascular medicine community.

Radiation and chemotherapeutics are associated with altered aortic aneurysm growth in cancer patients

INTRODUCTION

Co-prevalence of aorto-iliac aneurysm (i.e. AAA) and cancer confronts patients and physicians with two life-threatening diseases. Modern chemotherapeutics and target therapies might impact the aneurysm wall integrity and subsequently affect growth. The purpose of this study was to assess associations between malignancy, therapeutic regimens and the growth rates of aorto-iliac aneurysms.

PATIENTS AND METHODS

A retrospective single-center analysis identified patients with aneurysm + cancer. Patients with ≥2 CT angiograms over ≥6 months and additional malignancy were included. Clinical data and aneurysm diameters were analyzed. AAA growth under cancer therapy (chemotherapy/radiation) was compared to a non-cancer AAA control cohort and to meta-analysis data. Statistics included t-tests and a linear regression model with correction for initial aortic diameter and type of treatment.

RESULTS

From 2003 - 2020, 217 patients (median age 70 years; 92% male) with 246 aneurysms (58.8% AAA) and 238 malignancies were identified. Prostate (27%) and lung (16%) cancer were most frequently seen, 157 patients (72%) received chemotherapy and 105 patients (48%) radiation, thereof 79 (36.4%) both. Annual AAA growth was not significantly different for cancer and non-cancer patients (2.0±2.3 vs. 2.8±2.1mm/y, p=0.20). However, subgroup analyses revealed that radiation was associated with a significantly reduced aneurysm growth rate compared to cancer patients without radiation (1.1±1.3 vs. 1.6±2.1 mm/y, p=0.046) and to the non-cancer control cohort (1.7±1.9 vs. 2.8±2.1 mm/y, p=0.007). Administration of antimetabolites showed significantly increased AAA growth (+0.9mm/year, p=0.011), while e.g. topoisomerase inhibitors (-0.8mm/year, p=0.17) and anti-androgens (-0.5mm/year, p=0.27) showed a possible trend for reduced growth. Similar was observed for iliac aneurysms (n=85). Additionally, effects were persistent in combinations of chemotherapies (2.6±1.4 substances/patient).

CONCLUSION

Cancer patients with concomitant aortic aneurysms may require intensified monitoring when undergoing specific therapies, such as antimetabolites, since they may experience an increased aneurysm growth rate. Radiation may be associated with reduced aneurysm growth.

Can We Still Teach Open Repair of Abdominal Aortic Aneurysm in The Endovascular Era? Single-Center Analysis on The Evolution of Procedural Characteristics Over 15 Years

OBJECTIVE

In many vascular centers an endovascular first policy for the treatment of abdominal aortic aneurysms (AAA) has resulted in endovascular aortic repair (EVAR) outnumbering open aortic repair (OAR). The declining routine in OAR raises the question whether this might influence procedural outcomes and diminish surgical expertise for current and future vascular surgeons. We aimed to analyze OAR outcomes, AAA morphology and procedural details over the past 15 years while an endovascular first approach was successively implemented.

PARTICICPANTS AND DESIGN

All patients operated for (i)ntact infra-/juxtarenal AAA between January 1, 2005 and December 31, 2019 were identified. Outcome parameters were length of stay (hospital/ICU), in-hospital mortality and medical/surgical complications. Operative details were clamping zone, access and graft configuration. AAA anatomy including neck and iliac parameters was analyzed with Endosize©. Logistic regression, uni- and multivariate analysis were applied.

RESULTS

293 patients received elective OAR for iAAA. Baseline characteristics (age, sex, hypertension, smoking, occlusive disease, coronary disease, hyperlipidemia, diabetes, renal insufficiency and obesity) did not change over time. The number of OAR dropped significantly (-0.5 cases/year p = 0.02). The procedure time (2005-2007: 192.2 ± 87.5min to 2017-2019: 235.6 ± 88.2min; p = 0.0001) and the length of stay (2005-2007: 12.0 ± 7.9 to 2017-2019: 17.0 ± 23.1; p = 0.03) increased significantly, whereas the in-hospital mortality, length of ICU stay and complication rates didn't, nor did AAA anatomy. Upon multivariate analysis, annual number of OAR and any additional anastomosis significantly influenced procedure time, trainee involvement, for example, did not. Hospital length-of-stay depended on patient age (p = 0.002), complication rates (p < 0.0001) and procedure time (p = 0.006).

CONCLUSION

Mortality and complication rates for OAR have remained low and constant. With the increase of EVAR, the absolute number of OARs has decreased significantly. However, the total procedure time has increased and depends significantly on the annual number of OARs in total and per surgeon. This might influence outcome parameters and should be implanted in future surgical education.

Concomitantly discovered visceral artery aneurysms do rarely grow during cancer therapy

Visceral artery aneurysms (VAA) are a rare entity of arterial aneurysms with the imminent threat of rupture. The impact of cancer and chemotherapy on the growth of VAAs is unknown. A retrospective dual center cohort study of patients with concomitant VAA and different types of cancer was conducted and the impact of various chemotherapeutic agents on VAA growth was studied by sequential CT analysis. For comparison, a non-cancer all comer cohort with VAAs and no cancer was studied to compare different growth rates. The primary endpoint was aneurysm progress or regression >1.75 mm. Chi-square test, Fisher's exact test and Mann-Whitney test was used for statistical comparison. In the 17-year-period from January 2003 to March 2020, 59 patients with 30 splenic artery aneurysms, 14 celiac trunk aneurysms, 11 renal artery aneurysms and 4 other VAA and additional malignancy were identified. 20% of patients suffered from prostate cancer, the rest were heterogeneous. The most prevalent chemotherapies were alkylating agents (23%), antimetabolites (14%) and mitose inhibitors (10%). Eight patients had relevant growth of their VAA and one patient showed diameter regression (average growth rate 0.1 ± 0.5 mm/year). Twenty-nine patients with 14 splenic, 11 RAAs (seven right) and 4 celiac trunk aneurysms were available in the non-cancer comparison cohort (average growth rate 0.5 ± 0.9 mm/year, p = 0.058). However, the growth rate of patients receiving operative treatment for relevant VAA growth was significantly higher (p = 0.004). VAAs grow rarely, and rather slow. Cancer and/or chemotherapy do not significantly influence the annual growth rate. Additional control examinations seem unnecessary.

Vascular e-Learning During the COVID-19 Pandemic: The EL-COVID Survey

BACKGROUND

The corona virus disease (COVID-19) pandemic has radically changed the possibilities for vascular surgeons and trainees to exchange knowledge and experience. The aim of the present survey is to inventorize the e-learning needs of vascular surgeons and trainees as well as the strengths and weaknesses of vascular e-Learning.

METHODS

An online survey consisting of 18 questions was created in English, with a separate bilingual English-Mandarin version. The survey was dispersed to vascular surgeons and trainees worldwide through social media and via direct messaging from June 15, 2020 to October 15, 2020.

RESULTS

Eight hundred and fifty-six records from 84 different countries could be included. Most participants attended several online activities (>4: n = 461, 54%; 2-4: n = 300, 35%; 1: n = 95, 11%) and evaluated online activities as positive or very positive (84.7%). In deciding upon participation, the topic of the activity was most important (n = 440, 51.4%), followed by the reputation of the presenter or the panel (n = 178, 20.8%), but not necessarily receiving accreditation or certification (n = 52, 6.1%). The survey identified several shortcomings in vascular e-Learning during the pandemic: limited possibility to attend due to lack of time and increased workload (n = 432, 50.5%), no protected/allocated time (n = 488, 57%) and no accreditation or certification, while technical shortcomings were only a minor problem (n = 25, 2.9%).

CONCLUSIONS

During the COVID-19 pandemic vascular e-Learning has been used frequently and was appreciated by vascular professionals from around the globe. The survey identified strengths and weaknesses in current e-Learning that can be used to further improve online learning in vascular surgery.

Lenvatinib halts aortic aneurysm growth by restoring smooth muscle cell contractility

Abdominal aortic aneurysm (AAA) is a disease with high morbidity and mortality, especially when ruptured. The rationale of this study was to evaluate the repurposing of lenvatinib, a multi–tyrosine kinase inhibitor, in limiting experimental AAA growth targeting vascular smooth muscle cells (VSMCs) and angiogenesis. We applied systemic and local lenvatinib treatment to elastase-induced murine aortic aneurysms, and RNA profiling identified myosin heavy chain 11 (Myh11) as the most deregulated transcript. Daily oral treatment substantially reduced aneurysm formation in 2 independent mouse models. In addition, a large animal aneurysm model in hypercholesterolemic low-density lipoprotein receptor–knockout (LDLR^–/–) Yucatan minipigs was applied to endovascularly deliver lenvatinib via drug-eluting balloons (DEBs). Here, a single local endovascular delivery blocked AAA progression successfully compared with a DEB-delivered control treatment. Reduced VSMC proliferation and a restored contractile phenotype were observed in animal tissues (murine and porcine), as well as AAA patient-derived cells. Apart from increasing MYH11 levels, lenvatinib reduced downstream ERK signaling. Hence, lenvatinib is a promising therapy to limit aortic aneurysm expansion upon local endovascular delivery. The tyrosine kinase inhibitor was able to positively affect pathways of key relevance to human AAA disease, even in a potentially new local delivery using DEBs.

[Relationship between regional settlement structure and hospital incidence, type of therapy and mortality of non-ruptured abdominal aortic aneurysms]

INTRODUCTION

In Germany, the regional settlement structure is heterogenous, ranging from densely populated cities with a tight network of vascular health care to large regions in which access to health care is limited in terms of space and time. Therefore, the aim of this secondary data analysis was to investigate the association between the settlement structure of the patient's home district (KT), and the hospital incidence, type of therapy, and mortality of non-ruptured abdominal aortic aneurysms (nrAAA).

METHODS

The microdata of the DRG statistics of the Federal Statistical Office for the years 2005-2014 were evaluated. All patients with nrAAA (ICD-10 Code I71.4) who were admitted to a German hospital and treated by open surgery and endovascular repair were included. Classification of treatment was based on the German Operation and Procedure Code. Patients were grouped according to the settlement structure of their home district defined by the Federal Institute for Research on Building, Urban Affairs and Spatial Development (KT1 independent city, KT2 urban district, KT3 rural district, KT4 sparsely populated region). The age-, sex- and risk-adjusted association between the type of settlement structure and in-hospital mortality was analysed using a multivariable multi-level regression model. The Elixhauser co-morbidity score validated for administrative data was used for risk adjustment.

RESULTS

Of 95,452 cases included, 88 % were men. Mean age was 72 years. There were 28,970 (30 %) patients in KT1, 37,759 (40 %) in KT2, 14,442 (15 %) in KT3 and 14,281 (15 %) in KT4. The hospital incidence was 12.4 per 100,000 inhabitants in KT1, 11.8 in KT2, 10.8 in KT3 and 11.2 in KT4 (p <0.001, falling trend). The proportion of EVAR treatment was 56 % in KT1, 54 % in KT2, 57 % KT3, and 59 % in KT4 (p <0.001, increasing trend). The raw hospital mortality of patients from KT1 to KT4 was 3.4 %, 3.4 %, 3.2 % and 3.6 %, respectively (p=0.553 for trend). The multivariable regression analysis revealed no statistically significant association between the KT and hospital mortality (KT1=reference, RR KT2=0.97 [95% CI 0.79-1.15], RR KT3=0.98 [0.81-1.14], RR KT4=0.98 [0.86-1.11]).

CONCLUSIONS

The study shows that both the hospital incidence and the type of therapy (endovascular vs. open) differed between the settlement structural district types, but there is no urban-rural gap regarding in-hospital mortality of treated nrAAA.

Editor's Choice - Distribution of Care and Hospital Incidence of Carotid Endarterectomy and Carotid Artery Stenting: A Secondary Analysis of German Hospital Episode Data

OBJECTIVE

This is a description of the German healthcare landscape regarding carotid artery disease, assessment of hospital incidence time courses for carotid endarterectomy (CEA) and carotid artery stenting (CAS), and simulation of potential effects of minimum hospital caseload requirements for CEA and CAS.

METHODS

The study is a secondary data analysis of diagnosis related group statistics data (2005-2016), provided by the German Federal Statistical Office. Cases encoded by German operation procedure codes for CEA or CAS and by International Classification of Diseases (ICD-10) codes for carotid artery disease were included. Hospitals were categorised into quartiles according to annual caseloads. Linear distances to the closest hospital fulfilling hypothetical caseload requirements were calculated.

RESULTS

A total of 132 411 and 33 709 patients treated with CEA and CAS from 2012 to 2016 were included. CEA patients had lower rates of myocardial infarction (1.4% vs. 1.8%) and death (1.2% vs. 4.0%), and CAS patients were more often treated after emergency admission (38.1% vs. 27.1%). Age standardised annual hospital incidences were 67.2 per 100 000 inhabitants for CEA and 16.3 per 100 000 inhabitants for CAS. The incidence for CEA declined from 2005 to 2016, with CAS rising again until 2016 after having declined from 2010 to 2013. Regarding distance from home to hospital, centres offering CEA are distributed more homogeneously across Germany, compared with those performing CAS. Hypothetical introduction of minimum annual caseloads (> 20 for CEA; > 10 for CAS) imply that 75% of the population would reach their hospital after travelling 45 km for CEA and 70 km for CAS.

CONCLUSION

Differences in spatial distribution mean that statutory minimum annual caseloads would have a greater impact on CAS accessibility than CEA in Germany. Presumably because of a decline in carotid artery disease and a transition towards individualised therapy for asymptomatic patients, hospital incidence for CEA has been declining.

Early and Midterm Outcomes of Open and Endovascular Revascularization of Chronic Mesenteric Ischemia

Background

Revascularization strategies for chronic mesenteric ischemia (CMI) include open (OR) and endovascular (ER) modalities. The primary objective of this study was to analyze the safety and effectiveness of OR and ER and the impact of clinical and morphological variables on early and midterm outcomes in a consecutive series of CMI patients in a tertiary referral center.

Patients and methods

From 2004 to 2017, all CMI patients treated with OR and ER were retrospectively identified. Patient records, preoperative imaging, as well as peri- and postoperative outcomes were analyzed. Univariable and multivariable analysis was performed to identify clinical or morphological variables affecting reintervention rates within 2 years.

Results

In total, 63 patients (33% male; mean age 71, range 60–76 years) were treated by ER (41 patients) or OR (22 patients) for CMI. Mean follow-up was 26 (10–71) months. 30-day mortality was 0.0% after ER and 4.5% after OR (p = 0.069); 30-day morbidity was 9.8% vs. 31.8%, respectively (p = 0.030). Length of stay was significantly longer after OR (14 vs. 4 days; p < 0.001). Freedom from reintervention rate after 2 years was 82% after OR and 73% after ER (p = 0.14). Overall survival did not differ after 2 years (OR 85% vs. ER 86%; p = 0.35). Multivariable analysis revealed that smoking was associated with higher risk of reintervention (hazard ratio, HR: 4.14; 95% confidence interval, CI 1.11–15.53; p = 0.03). Additionally, a nonsignificant trend of lower reintervention rates after OR was detected (HR 0.23 95% CI 0.05–1.08; p = 0.06).

Conclusion

Due to a lower invasiveness, despite the higher reintervention rate, an “endovascular first” strategy is justified and recommended.

Lack of durability after transarterial ethylene-vinyl alcohol copolymer-embolization of type II endoleak following endovascular abdominal aortic aneurysm repair

Background: Type II endoleak (T2EL) after endovascular aortic repair is associated with AAA sac enlargements in up to 25%, reduction of attachment zones and rarely with aortic rupture. Indications for therapy and efficacy of interventions of T2EL are not clearly established. Transarterial embolization with application of ethylene-vinyl alcohol copolymer has been described with varying outcomes. Aim of this study is to evaluate durability of Onyx^TM embolization (OE) in T2EL in a consecutive series at a single tertiary vascular center. Patients and methods: Demographic data, technical success, pre- and postoperative aneurysm growth, morbidity, mortality and reintervention rates during hospital stay as well as in follow up were recorded in patients treated with OE for T2EL between 01/2015 and 12/2017. The primary endpoint was defined as persistence or reoccurrence of T2EL (durability of OE). Results: In total 15 patients (78 ± 6 years, 13 men) were treated with OE because of sac enlargement (average growth of 12 ± 8%, n = 12), persistent bleeding after AAA rupture (n = 2) or persistent T2EL with stable but large aneurysm diameter (n = 1). Mean length of stay was 8 ± 11 days. Technical success was 93.3% (n = 14). Inhospital-morbidity was 26.7%, in-hospital- and 1-year-mortality rate were 6.6% (n = 1) and 20.0% (n = 3). T2EL persisted in 20.0% (n = 3) despite of OE. Re-EL-II occurred after 40 (30-114) days in 33.3% (n = 5). Reintervention rate was 13.3% (n = 2, at day 48 and 319). Altogether clinical success with stable aneurysm diameter was achieved in 80.0% (n = 12), but durable elimination of EL was only achieved in 46.7% of patients (n = 7). Conclusions: OE is technically possible in more than 90% of patients but might be associated with severe complications. Durability of this treatment is low, since T2EL persist or reoccur in more than 50% of all patients. OE of T2EL should be reserved for few selected cases.

The Effects of Minimum Caseload Requirements on Management and Outcome in Abdominal Aortic Aneurysm Repair

BACKGROUND

The German quality assurance guideline on abdominal aortic aneurysm (AAA) was implemented by the Joint Federal Committee (Gemeinsamer Bundesausschuss, G-BA) in 2008. The aims of this study were to verify the association between hospital case volume and outcome and to assess the hypothetical effect of minimum caseload requirements.

METHODS

The German diagnosis-related groups statistics for the years 2012 to 2016 were scrutinized for AAA (ICD-10 GM I71.3/4) with procedure codes for endo - vascular or open surgical treatment. The primary endpoint was in-hospital mortality. Logistic regression models were used for risk adjustment, and odds ratios (OR) were calculated as a function of the annual hospital-level case volume of AAA. In a hypo - thetical approach, the linear distances for various minimum caseloads (MC) were evaluated to assess accessibility.

RESULTS

The mortality of intact AAA (iAAA) was 2.7% (men [M] 2.4%, women [W] 4.2%); ruptured AAA (rAAA), 36.9% (M 36.9%, F 37.5%). An inverse relationship between annual hospital case volume of AAA and mortality was confirmed (iAAA/rAAA: from 3.9%/51% [<10 cases/year] through 3.3%/37% [30-39 cases/year] to 1.9%/28% [≥ 75 cases/year]). For a reference category of 30 AAA procedures/year, the following significant OR were found: 10 AAA cases/year, OR 1.21 (95% confidence interval [1.20; 1.21]); 20 cases, OR 1.09 [1.09; 1.09]; 50 cases, OR 0.89 [0.89; 0.89]; 75 cases, OR 0.82 [0.82; 0.82]. In a hypothetical centralization scenario with assumed MC of 30/year, 86% of the population would have to travel less than 100 km to the nearest hospital; with an MC of 40, this would apply to only 50% (without redistribution effects).

CONCLUSION

In the observed period, a significant correlation was confirmed between high annual case volume and low in-hospital mortality. A minimum caseload requirement of 30 AAA operations/year seems reasonable in view of the accessibility of hospitals. Cite this.

Hospital Incidence and In-Hospital Mortality of Surgically and Interventionally Treated Aortic Dissections: Secondary Data Analysis of the Nationwide German Diagnosis-Related Group Statistics From 2006 to 2014

Background

Population‐based data about the incidence and mortality of patients with aortic dissections (ADs) are sparse. Therefore, the hospital incidence and in‐hospital mortality of patients undergoing open or endovascular surgery for type A ADs (TAADs) and type B ADs (TBADs) in Germany were analyzed on a nationwide basis between 2006 and 2014.

Methods and Results

A secondary data analysis of the nationwide diagnosis‐related group statistics, compiled by the German Federal Statistical Office, was performed for patients who were surgically/interventionally treated for AD (International Classification of Diseases, Tenth Revision, German Modification [ICD‐10‐GM] codes I71.00‐I71.07; n=20 533). By using specific procedure codes, a distinction between TAAD (n=14 911/72.6%) and TBAD (n=5622/27.4%) could be made. The standardized hospital incidence of surgically/interventionally treated AD was 2.7/100 000 per year, comprising 2.0/100 000 per year for TAAD and 0.7/100 000 per year for TBAD. The in‐hospital mortality of TAAD was 19.5%; and of TBAD, 9.3%. Both the incidence and in‐hospital mortality increased over the 9‐year period. The share of endovascularly treated TBAD increased steadily during the same time interval. A multilevel multivariable analysis revealed that, for TAAD, age and comorbidity were significantly associated with a higher mortality risk.

The latter was also true for TBAD. Sex was not significantly associated with mortality. A significant association between higher annual center volume and mortality was found for TAAD, but not for TBAD.

Conclusions

This is the first report on hospital incidence and mortality for surgically/interventionally treated AD on a nationwide basis. Overall, in Germany, hospital incidence and mortality of TAAD and TBAD increased over time. In addition, TAAD is performed more safely in high‐volume centers.

See Editorial Svensson

Effect Modification of Sex and Age for the Hospital Volume-Outcome Relationship in Abdominal Aortic Aneurysm Treatment: Secondary Data Analysis of the Nationwide German Diagnosis Related Groups Statistics From 2005 to 2014

Background Trials and registries associated female sex and high age with unfavorable outcomes in abdominal aortic aneurysm treatment. Many studies showed an inverse correlation between annual hospital volume and in-hospital mortality. The volume-outcome relationship has not been investigated separately for women and men or across the age range. The aim was to analyze whether sex and age are effect modifiers or confounders of the volume-outcome association. Methods and Results In a nationwide setting, all in-hospital cases from 2005 to 2014 with a diagnosis of intact abdominal aortic aneurysm and procedure codes for endovascular or open aortic repair were included. Primary outcome was in-hospital mortality. Using a multilevel multivariable regression model, hospital volume was modeled as a continuous variable. Separate analyses were performed for women and men and for predefined age groups. A total of 94 966 cases were included (12% women; median age, 72 years). Mortality was 4.9% in women and 3.0% in men (3.2% overall). Mortality increased with age. Although there was no significant volume-outcome association in women (P=0.57), there was in men (P=0.02). The strongest volume-outcome association was found in younger men. The younger female subpopulation was found to show a trend for an inverse volume-outcome relationship, whereas an opposite association was found for the women aged >79 years. Conclusions Women have a higher mortality risk after elective abdominal aortic aneurysm treatment. Sex and age are modifiers of the volume-outcome relationship. Unlike in male patients, in women there is no consistent effect of hospital volume on outcome.

Regional variation in endovascular treatment rate and in-hospital mortality of abdominal aortic aneurysms in Germany

Summary: Background: Abdominal aortic aneurysms (AAA) can be treated by either open surgery (OAR) or endovascular aortic repair (EVAR). The aim of this study was to analyze regional variations in application of (EVAR) and in-hospital mortality after intact AAA (iAAA) repair. Methods: Using data provided by the German Federal Statistical Office, a nationwide analysis for 2012 to 2014 was conducted. Patients with a diagnosis of iAAA (I71.4) and corresponding procedure codes for OAR (5-384.5/7) or EVAR (5-38a.1) were included. Odds ratios (ORs) for use of EVAR (proportion of EVAR among total EVAR + OAR cases) and mortality were calculated for all regions in Germany. ORs for EVAR use were adjusted for age, sex, and risk (Elixhauser score). ORs for mortality were additionally adjusted for type of procedure (OAR/EVAR). Results: Finally, 31,757 procedures for iAAA were included. Median age of all patients was 73 years (interquartile range 67–78 years) and 87.1 % were male. The mean proportion of EVAR procedures was 72.6 %; however, the application of EVAR for repair of iAAA varied widely depending on region. The lowest unadjusted regional rate of EVAR use was 48.8 %, while the highest was 92.5 %. After adjustment, the lowest regional OR for EVAR use (compared to the nationwide mean) was 0.23 (95 % confidence interval [0.15–0.36]), the highest 5.93 [1.79–19.65]. Overall in-hospital mortality was 2.9 % (OAR 6.2 %; EVAR 1.7 %). The adjusted regional OR for mortality ranged from 0.31 [0.07–1.42] to 4.98 [2.08–11.93]. Conclusions: This study reveals variations in use of EVAR and in-hospital mortality for iAAA treatment in Germany. This may imply that selection of treatment might not only be influenced by patient characteristics, but also by regional location. These results need to be taken into account when discussing centralization of AAA treatment in Germany.

Long noncoding RNAs in key cellular processes involved in aortic aneurysms

Aortic aneurysm (AA) is a complex and dangerous vascular disease, featuring progressive and irreversible vessel dilatation. AA is typically detected either by screening, or identified incidentally through imaging studies. To date, no effective pharmacological therapies have been identified for clinical AA management, and either endovascular repair or open surgery remains the only option capable of preventing aneurysm rupture. In recent years, multiple research groups have endeavored to both identify noncoding RNAs and to clarify their function in vascular diseases, including aneurysmal pathologies. Notably, the molecular roles of noncoding RNAs in AA development appear to vary significantly between thoracic aortic aneurysms (TAAs) and abdominal aortic aneurysms (AAAs). Some microRNAs (miRNA - a non-coding RNA subspecies) appear to contribute to AA pathophysiology, with some showing major potential for use as biomarkers or as therapeutic targets. Studies of long noncoding RNAs (lncRNAs) are more limited, and their specific contributions to disease development and progression largely remain unexplored. This review aims to summarize and discuss the most current data on lncRNAs and their mediation of AA pathophysiology.

•

This current review covers studies that have identified long non-coding RNAs in aortic aneurysm development and progression.

•

We separately discuss transcripts and mechanisms of importance to thoracic as well as abdominal aortic aneurysms.

•

Functional data on lncRNAs being identified are highlighted.

•

Some have been studied in human as well as experimental models of the disease pathology.

Effects of Iliac Stenosis on Abdominal Aortic Aneurysm Formation in Mice and Humans

Reduced lower-limb blood flow has been shown to lead to asymmetrical abdominal aortic aneurysms (AAAs) but the mechanism of action is not fully understood. Therefore, small animal ultrasound (Vevo2100, FUJIFILM VisualSonics) was used to longitudinally study mice that underwent standard porcine pancreatic elastase (PPE) infusion (n = 5), and PPE infusion with modified 20% iliac artery stenosis in the left (n = 4) and right (n = 5) iliac arteries. Human AAA computed tomography images were obtained from patients with normal (n = 9) or stenosed left (n = 2), right (n = 1), and bilateral (n = 1) iliac arteries. We observed rapid early growth and rightward expansion (8/9 mice) in the modified PPE groups (p < 0.05), leading to slightly larger and asymmetric AAAs compared to the standard PPE group. Further examination showed a significant increase in TGFβ1 (p < 0.05) and cellular infiltration (p < 0.05) in the modified PPE group versus standard PPE mice. Congruent, yet variable, observations were made in human AAA patients with reduced iliac outflow compared to those with normal iliac outflow. Our results suggest that arterial stenosis at the time of aneurysm induction leads to faster AAA growth with aneurysm asymmetry and increased vascular inflammation after 8 weeks, indicating that moderate iliac stenosis may have upstream effects on AAA progression.

Biobanking: Objectives, Requirements, and Future Challenges-Experiences from the Munich Vascular Biobank

Collecting biological tissue samples in a biobank grants a unique opportunity to validate diagnostic and therapeutic strategies for translational and clinical research. In the present work, we provide our long-standing experience in establishing and maintaining a biobank of vascular tissue samples, including the evaluation of tissue quality, especially in formalin-fixed paraffin-embedded specimens (FFPE). Our Munich Vascular Biobank includes, thus far, vascular biomaterial from patients with high-grade carotid artery stenosis (n = 1567), peripheral arterial disease (n = 703), and abdominal aortic aneurysm (n = 481) from our Department of Vascular and Endovascular Surgery (January 2004–December 2018). Vascular tissue samples are continuously processed and characterized to assess tissue morphology, histological quality, cellular composition, inflammation, calcification, neovascularization, and the content of elastin and collagen fibers. Atherosclerotic plaques are further classified in accordance with the American Heart Association (AHA), and plaque stability is determined. In order to assess the quality of RNA from FFPE tissue samples over time (2009–2018), RNA integrity number (RIN) and the extent of RNA fragmentation were evaluated. Expression analysis was performed with two housekeeping genes—glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB)—using TaqMan-based quantitative reverse-transcription polymerase chain reaction (qRT)-PCR. FFPE biospecimens demonstrated unaltered RNA stability over time for up to 10 years. Furthermore, we provide a protocol for processing tissue samples in our Munich Vascular Biobank. In this work, we demonstrate that biobanking is an important tool not only for scientific research but also for clinical usage and personalized medicine.

Incidence, Treatment and Mortality in Patients with Abdominal Aortic Aneurysms

BACKGROUND

Aim of this study was to analyze hospital incidence, type of treatment, and hospital mortality rates of patients with abdominal aortic aneurysm (AAA) in Germany from 2005 to 2014.

METHODS

Microdata of the diagnosis-related group (DRG) statistics compiled by the German Federal Statistical Office for the years 2005-2014 were analyzed. Patients who were hospitalized for a ruptured AAA (rAAA, ICD-10 code I71.3, treated either surgically or conservatively) or received surgical treatment for an unruptured AAA (nrAAA, ICD-10-Code I71.4, treated either with open surgery or an endovascular procedure) were included in the analysis. The "European Standard Population 2013" was used for direct standardization of the hospital incidences. In-hospital mortality was calculated with standardization for age and risk.

RESULTS

The standardized overall hospital incidence of AAA was 27.9 and 3.3 cases per 100 000 people for men and women, respectively; over the period of the study, the incidence of rAAA fell by 30% in both sexes and that of nrAAA rose by 16% in men and 42% in women. The percentage of patients receiving endovascular treatment rose from 29% to 75% in patients with nrAAA and from 8% to 36% in patients with rAAA. The age- and risk-standardized in-hospital mortality of nrAAA was 3.3% in men and 5.3% in women. The in-hospital mortality of surgically treated rAAA was 39% in men and 48% in women.

CONCLUSION

The hospital incidence of AAA rose from 2005 to 2014, while that of rAAA fell. Endovascular treatment became more common for nrAAA as well as rAAA, and in-hospital mortality fell for both.

Open Versus Endovascular Repair of Isolated Iliac Artery Aneurysms

PURPOSE:

Outcomes of open iliac artery repair (OIR) and endovascular iliac artery repair (EVIR) were compared at a tertiary referral vascular center.

METHODS:

From 2004 to 2015, all patients treated for isolated iliac artery aneurysms (IAAs) were retrospectively identified, and patient records and computed tomography (CT) scans were analyzed. The primary end point was overall survival; secondary end points were 30-day mortality and morbidity and freedom from reintervention. For follow-up, data from outpatient visits and CT scans following a standard surveillance protocol were used.

RESULTS:

A total of 106 IAAs in 94 patients were treated (mean follow-up: 35.7 months; 66 OIR; 40 EVIR). Six (15%) aneurysms from the EVIR group and 4 (6.1%) from open-operated IAA presented in the state of rupture. There was no difference in overall survival between EVIR and OIR ( P = .14). In multivariable analysis, higher risk of death was associated with ruptured IAA (rIAA; hazard ratio [HR]: 40.44, 95% confidence interval [CI]: 2.05-796.18; P = .02) and coronary heart disease (HR: 11.07, 95% CI: 1.94-63.36; P < .01). The 30-day mortality was 1.9% overall (0% OIR, 5.0% EVIR, P = .27), but there were no differences between OIR and EVIR in 30-day morbidity ( P = .11). Freedom from reintervention was higher for OIR than for EVIR ( P < .01). In multivariable analysis, a higher reintervention rate was seen in EVIR (HR: 10.80, 95% CI: 2.20-53.01; P < .01) and in rIAA (HR: 12.02, 95% CI: 1.31-111.11; P = .03).

CONCLUSION:

Iliac artery aneurysmss can be safely and effectively treated by EVIR or OIR regarding 30-day morbidity, mortality, and long-term survival, although freedom from reintervention is significantly lower after EVIR.

Spatial Analysis of Hospital Incidence and in Hospital Mortality of Abdominal Aortic Aneurysms in Germany: Secondary Data Analysis of Nationwide Hospital Episode (DRG) Data

OBJECTIVE

This study aimed to analyze the spatial distribution and regional variation of the hospital incidence and in hospital mortality of abdominal aortic aneurysms (AAA) in Germany.

METHODS

German DRG statistics (2011-2014) were analysed. Patients with ruptured AAA (rAAA, I71.3, treated or not) and patients with non-ruptured AAA (nrAAA, I71.4, treated by open or endovascular aneurysm repair) were included. Age, sex, and risk standardisation was done using standard statistical procedures. Regional variation was quantified using systematic component of variation. To analyse spatial auto-correlation and spatial pattern, global Moran's I and Getis-Ord Gi* were calculated.

RESULTS

A total of 50,702 cases were included. Raw hospital incidence of AAA was 15.7 per 100,000 inhabitants (nrAAA 13.1; all rAAA 2.7; treated rAAA 1.6). The standardised hospital incidence of AAA ranged from 6.3 to 30.3 per 100,000. Systematic component of variation proportion was 96% in nrAAA and 55% in treated rAAA. Incidence rates of all AAA were significantly clustered with above average values in the northwestern parts of Germany and below average values in the south and eastern regions. Standardised mortality of nrAAA ranged from 1.7% to 4.3%, with that of treated rAAA ranging from 28% to 52%. Regional variation and spatial distribution of standardised mortality was not different from random.

CONCLUSIONS

There was significant regional variation and clustering of the hospital incidence of AAA in Germany, with higher rates in the northwest and lower rates in the southeast. There was no significant variation in standardised (age/sex/risk) mortality between counties.

Cathepsin S is associated with degradation of collagen I in abdominal aortic aneurysm

BACKGROUND

Cathepsins have been described in the pathogenesis of abdominal aortic aneurysm (AAA), their exact role, especially in collagen degradation, is still unclear. The aim of the present study was therefore to analyse relevant cathepsins in human AAA tissue samples in relation to collagen I, III, and their degradation products.

MATERIALS AND METHODS

Samples from 37 AAA patients obtained from elective open surgical repair and eight healthy non-aneurysmatic aortas from kidney donors were included. Expression of cathepsins B, D, K, L, S, cystatin C, collagen I and III, their degraded products C-Telopeptide of type 1 and 3 collagen (CTX-I, CTX-III), cellular markers for leukocytes (CD45), T cells (CD3), macrophage scavenger receptor-1 (MSR-1), synthetic, and contractile smooth muscle cells (SMCs) (smoothelin: SMTH, collagen I and III, myosin heavy chain: MHC, embryonic smooth muscle myosin heavy chain: SMemb) were determined at messenger RNA (mRNA) level, using SYBRGreen-based quantitative PCR and at protein level using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Expression of cathepsins B, D, L, and S at mRNA level was significantly elevated in AAA compared to control aorta (1.7-fold, p = 0.025; 2.5-fold, p = 0.002; 2.6-fold, p = 0.034; and 7.0-fold, p = 0.003). Expression of cathepsin S correlated significantly with leukocytes and macrophages (ρ = 0.398, p = 0.033 and ρ = 0.422, p = 0.020), synthetic SMCs were significantly associated with cathepsins B, D, and L (ρ = 0.522, p = 0.003; ρ = 0.431, p = 0.015 and ρ = 0.467, p = 0.008). At protein level, cathepsins B and S were elevated in AAA compared to controls (5.4-fold, p = 0.001 and 7.3-fold, p < 0.001). Significant correlations were observed between collagen I, its degraded product, and cathepsin S (r = -0.350, p = 0.034 and r = +0.504, p < 0.001). Expression of cathepsin B was associated with SMCs, expression of cathepsin S with inflammatory cells.

CONCLUSIONS

Particularly cathepsin S was associated with the degradation product of collagen I and thus might be involved in the progression of AAA. Furthermore, cathepsin S correlated with inflammatory cells.

Nationwide analysis of risk factors for in-hospital mortality in patients undergoing abdominal aortic aneurysm repair

BACKGROUND

There is increasing awareness that women may have worse outcomes following repair of abdominal aortic aneurysm (AAA). The aim of this study was to analyse the association between sex, age and in-hospital mortality after AAA using hospital episode data collected routinely at the nationwide level.

METHODS

Data were extracted from the nationwide statutory Diagnosis Related Group statistics provided by the German Federal Statistical Office. Patients with a diagnosis of intact (non-ruptured) AAA (ICD-10 GM I71.4) and procedure codes (OPS; 2005-2013) for endovascular aneurysm repair (EVAR) (5-38a.1*) or open aneurysm repair (5-384.5, 5-384.7), treated from 2005 to 2013, were included. A multilevel multivariable regression model was applied to adjust for medical risk (using the Elixhauser co-morbidity score), type of procedure, type of admission, and to account for clustering of patients within centres. The primary outcome was in-hospital mortality.

RESULTS

Some 84 631 patients were identified, of whom 10 039 (11·9 per cent) were women. Women were significantly older than men at admission (median 74 (i.q.r. 69-80) versus 72 (66-77) years; P < 0·001). EVAR was used less frequently in women (48·1 versus 54·7 per cent; P < 0·001). The in-hospital mortality rate was higher in women, overall (5·0 versus 3·1 per cent; relative risk 1·60, 95 per cent c.i. 1·45 to 1·75), and for EVAR (2·8 versus 1·5 per cent; RR 1·90, 1·60 to 2·30) and open repair (6·8 versus 5·0 per cent; RR 1·36, 1·22 to 1·52). In-hospital mortality increased with age and was highest in patients aged over 80 years. In multivariable regression analysis, female sex (RR 1·20, 1·07 to 1·35) and age per 10-year increase (RR 1·83, 1·73 to 1·95) were independent risk factors for higher in-hospital mortality.

CONCLUSION

In Germany, women were older when undergoing AAA repair and were less likely to receive EVAR. Mortality rates were higher in older patients and in women, irrespective of the surgical technique used.

Association of Matrix Metalloproteinase Levels with Collagen Degradation in the Context of Abdominal Aortic Aneurysm

OBJECTIVE/BACKGROUND

Matrix metalloproteinases (MMPs) have already been identified as key players in the pathogenesis of abdominal aortic aneurysm (AAA). However, the current data remain inconclusive. In this study, the expression of MMPs at mRNA and protein levels were investigated in relation to the degradation of collagen I and collagen III.

METHODS

Tissue samples were obtained from 40 patients with AAA undergoing open aortic repair, and from five healthy controls during kidney transplantation. Expression of MMPs 1, 2, 3, 7, 8, 9, and 12, and tissue inhibitor of metalloproteinase (TIMP)1, and TIMP2 were measured at the mRNA level using quantitative reverse transcription polymerase chain reaction. At the protein level, MMPs, collagen I, and collagen III, and their degradation products carboxy-terminal collagen cross-links (CTX)-I and CTX-III, were quantified via enzyme linked immunosorbent assay. In addition, immunohistochemistry and gelatine zymography were performed.

RESULTS

In AAA, significantly enhanced mRNA expression was observed for MMPs 3, 9, and 12 compared with controls (p ≤ .001). MMPs 3, 9, and 12 correlated significantly with macrophages (p = .007, p = .018, and p = .015, respectively), and synthetic smooth muscle cells with MMPs 1, 2, and 9 (p = .020, p = .018, and p = .027, respectively). At the protein level, MMPs 8, 9, and 12 were significantly elevated in AAA (p = .006, p = .0004, and p < .001, respectively). No significant correlation between mRNA and protein was observed for any MMP. AAA contained significantly reduced intact collagen I (twofold; p = .002), whereas collagen III was increased (4.6 fold; p < .001). Regarding degraded collagen I and III relative to intact collagens, observations were inverse (1.4 fold increase for CTX-1 [p < .001]; fivefold decrease for CTX-III [p = .004]). MMPs 8, 9, and 12 correlated with collagen I (p = .019, p < .001, and p = 0.003, respectively), collagen III (p = .015, p < .001, and p < .001, respectively), and degraded collagen I (p = .012, p = .049, and p = .001, respectively).

CONCLUSION

No significant relationship was found between mRNA and protein and MMP levels. MMPs 9 and 12 were overexpressed in AAA at the mRNA and protein level, and MMP-8 at the protein level. MMP-2 was detected in synthetic SMCs. Collagen I and III showed inverse behaviour in AAA. In particular, MMPs 8, 9, and 12 appear to be associated with collagen I, collagen III, and their degradation products.

Trends in Patient Safety of Intact Abdominal Aortic Aneurysm Repair: German Registry Data on 36,594 Procedures

OBJECTIVE/BACKGROUND

The study aim was to determine whether patient safety for non-ruptured abdominal aortic aneurysm (nrAAA) repair has changed between 1999 and 2010 in a large German cohort.

METHODS

The data source was the prospective quality assurance registry of the German Vascular Society from 1999 to 2010. Patient characteristics, surgical techniques (open aortic repair [OAR], endovascular aortic repair [EVAR]), procedural time and outcomes, including the length of hospital stay (LOS), were analysed using the Cochran-Armitage test for binary parameters and Spearman's correlation coefficient for quantitative parameters.

RESULTS

A total of 36,594 operations (23,037 OAR, 13,557 EVAR) for infrarenal nrAAA in 201 hospitals in Germany were investigated. Patients' mean age increased from 69.6 to 72.0 years (p < .001). The rate of patients with American Society of Anesthesiologists scores of 3 or 4 increased (p < .001). Use of EVAR increased (1999: 16.7%; 2010: 62.7%; p < .001), and since 2009, EVAR has been more frequently used than OAR. The overall in hospital mortality decreased from 3.1% in 1999 to 2.3% in 2010 (p < .001). There were no temporal trends for mortality rates for EVAR (p = .233) or OAR (p = .281) when considered separately. Cardiac (1999: 8.1%; 2010: 5.1%; p < .001) and pulmonary (1999: 7.8%; 2010: 4.8%; p < .001) complications decreased. The rate of post-operative renal failure increased (1999: 3.6%; 2010 4.1%; p = .017), without increasing the rate of patients needing dialysis (1999: 1.7%; 2010: 1.7%; p = .171). The median LOS decreased from 17 days in 1999 to 10 days in 2010 (p < .001).

CONCLUSION

This study shows significantly improved post-procedural in hospital outcomes and decreased use of resources for nrAAA repair. This trend can probably be attributed to the implementation of EVAR as a standard technique, but some trends could also possibly be explained by a change in the remuneration system. The main limitation of the registry is the lack of internal and external validation. However, in hospital patient safety for AAA repair seems to have improved significantly in the participating hospitals.