Henrik Christian Rieß

Registry and health insurance claims data in vascular research and quality improvement

The expansion of procedures in multidisciplinary vascular medicine has sparked a controversy regarding measures of quality improvement. In addition to primary registries, the use of health insurance claims data is becoming of increasing importance. However, due to the fact that health insurance claims data are not collected for scientific evaluation but rather for reimbursement purposes, meticulous validation is necessary before and during usage in research and quality improvement matters. This review highlights the advantages and disadvantages of such data sources. A recent comprehensive expert opinion panel examined the use of health insurance claims data and other administrative data sources in medicine. Results from several studies concerning the validity of administrative data varied significantly. Validity of these data sources depends on the clinical relevance of the diagnoses considered. The rate of implausible information was 0.04 %, while the validity of the considered diagnoses varied between 80 and 97 % across multiple validation studies. A matching study between health insurance claims data of the third-largest German health insurance provider, DAK-Gesundheit, and a prospective primary registry of the German Society for Vascular Surgery demonstrated a good level of validity regarding the mortality of endovascular and open surgical treatment of abdominal aortic aneurysm in German hospitals. In addition, a large-scale international comparison of administrative data for the same disorder presented important results in treatment reality, which differed from those from earlier randomized controlled trials. The importance of administrative data for research and quality improvement will continue to increase in the future. When discussing the internal and external validity of this data source, one has to distinguish not only between its intended usage (research vs. quality improvement), but also between the included diseases and/or treatment procedures. Linkage between primary registry data and administrative data could be a reasonable solution to some current major issues of validity.
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Short-term and long-term results of endovascular and open repair of abdominal aortic aneurysms in Germany

Background: Endovascular aortic repair (EVAR) has emerged as a standard of care for abdominal aortic aneurysm (AAA) repair. However, real‐world evidence to compare this technology to open aortic repair (OAR) is limited. Major gaps exist related to long‐term outcomes of therapies worldwide. Methods: Health insurance claims data of Germanys third largest insurance provider, DAK‐Gesundheit, were used to determine outcomes after interventions for intact AAA (iAAA) and ruptured AAA (rAAA). The study included patients operated on between October 2008 and April 2015. Results: Included were 5509 patients (3627 EVAR and 1859 OAR). Median follow‐up was 2.44 years (range, 0–6.46 years). The in‐hospital mortality was lower after EVAR compared with OAR for both iAAA (1.2% vs 5.4%) and rAAA (26.1% vs 42%; P < .001). Postoperative length of stay and occurrence of complications were also lower after EVAR. The in‐hospital mortality benefits of EVAR were most prominent in octogenarians (iAAA: EVAR, 2.2%; OAR, 18.2%; rAAA: EVAR, 34.4%; OAR, 62.3%; P < .001). However, the early survival benefit after EVAR reversed at ˜1.5 years, and Cox proportional hazard models revealed no differences in overall survival between EVAR and OAR. Landmark analysis focusing on patients surviving the procedure has shown lower survival in patients with EVAR. Conclusions: In this largest European investigation to date using health insurance claims data, we found that in‐hospital outcomes in Germany favor EVAR, which is comparable to findings reported in the United States and the United Kingdom. Trends toward lower long‐term survival after EVAR after discharge are important and require future research and reflection.

Gender differences in endovascular treatment of infrainguinal peripheral artery disease

BACKGROUND Despite ongoing research concerning comorbidities and clinical presentation of peripheral arterial disease (PAD), the issue of gender associated differences in treatment is far from being settled. PATIENTS AND METHODS This was a prospective, non-randomized multicentre study design. All patients suffering from intermittent claudication (IC) or critical limb ischaemia (CLI) were included. RESULTS A total of 2,798 procedures for symptomatic PAD in the infrainguinal region were recorded, with 1,696 (61.4 %) males. Distribution of comorbidities for patients with IC were gender-specifically different. Smoking was more common in men (41.9 vs. 31.9 %, p < .001), men had more often previous coronary heart disease (35.2 vs. 27.7 %, p = .007), and suffered more often from diabetes (33.9 vs. 28.2 %, p = .037). Women were generally older (71 vs. 77 years). Men were more prone to present with IC (46.9 vs. 43.6 %, p < .001) and ulcer/gangrene (43.6 vs. 41.2 %, p < .001). Women were more likely to present with rest pain (9.5 vs. 15.1 %, p < .001). Men were more often treated for a lesion below the knee (BTK) (21.1 vs. 14.9 %, p < .001), and females above the knee (ATK) (58.1 vs. 61.5 %, p < .001). Logistic regression analysis revealed a significant association of male gender and treatment for lesions BTK (OR 1.565, 95 % CI 1.281-1.913, p < .001). Dissections and bleeding complications were more often observed in females with IC (3.3 vs. 7.2 %, p = 0.003; 0.4 vs. 1.5 %, p = 0.044). Women were rather discharged to rehabilitation and had a longer hospital stay compared to men (3.4 vs. 8.9 %, p < .001; three vs. four days, p = .023). CONCLUSIONS The present study provides an overview on gender-specific differences in endovascular treatment of PAD. To date, available evidence on this topic is limited, emphasising the importance of further vascular research targeting this topic.

Gender differences in abdominal aortic aneurysms in Germany using health insurance claims data

BACKGROUND Endovascular aortic repair (EVAR) has emerged as standard of care for abdominal aortic aneurysm (AAA). Real-world evidence is limited to compare this technology to open repair (OAR). Major gaps exist related to short-term and long-term outcomes, particularly in respect of gender differences. MATERIALS AND METHODS Health insurance claims data from Germanys third largest insurance provider, DAK-Gesundheit, was used to investigate invasive in-hospital treatment of intact (iAAA) and ruptured AAA (rAAA). Patients operated between October 2008 and April 2015 were included in the study. RESULTS A total of 5,509 patients (4,966 iAAA and 543 rAAA) underwent EVAR or OAR with a median follow-up of 2.44 years. Baseline demographics, comorbidities, and clinical characteristics of DAK-G patients were assessed. In total, 84.6 % of the iAAA and 79.9 % of the rAAA were male. Concerning iAAA repair, the median age (74 vs. 73 years, p < .001) compared to men was higher in females, but their EVAR-rate (66.8 % vs. 71.1 %, p = .018) was lower. Besides higher age of female patients (80 vs. 75 years, p < .001), no further statistically significant differences were seen following rAAA repair. In-hospital mortality was slightly lower in males compared to females following iAAA (2.3 % vs. 3.1 %, p = .159) and rAAA (37.3 % vs. 43.1 %, p = .273) repair. Concerning iAAA repair, a higher rate of female patients was transferred to another hospital (3.7 % vs. 2.0 %, p = 0.008) or discharged to rehabilitation (6.0 % vs. 2.7 %, p < .001) compared to male patients. CONCLUSIONS In this large German claims data cohort, women are generally older and more often transferred to another hospital or discharged to rehab following iAAA repair. Nonetheless, no significantly increased risk of in-hospital or late death appeared for women in multivariate analyses. Further studies are necessary to evaluate the impact of recent gender-specific treatment strategies on overall outcome under real-world settings.

Indicators of outcome quality in peripheral arterial disease revascularisations – a Delphi expert consensus

INTRODUCTION Peripheral arterial disease (PAD) affects a continuously increasing number of people worldwide leading to more invasive treatments. Indication to perform invasive revascularisations usually arises from consensus-based recommendations of practice guidelines and from few randomized controlled trials where outcome measures focus mainly on risk factors associated with mortality and morbidity. To date, no broad consensual agreement of experts on valid indicators of outcome quality exists for PAD. METHODS A literature review was conducted to collect indicators of outcome quality from studies of PAD. The Delphi technique was used to achieve a consensual agreement on a set of core indicators. The expert panel of the two-round Delphi approach was formed by leading vascular specialists joining the IDOMENEO study, physician assistants, wound nurses, and patient representatives. Items were scored via a web-based anonymised electronic questionnaire using a five-point Likert-scale. RESULTS Out of 40 invited experts 30 joined the panel and completed round one. Twenty-four experts completed the second and final round. Forty-three indicators of outcome quality were initially identified and validated by the panel. After two Delphi rounds, 12 indicators (27.9 %) achieved the limit of agreement for relevance and four (9.3 %) for practicability. Major adverse limb events (MALE), major amputation, and major re-intervention (or re-operation) were consented as both highly relevant and practicable. Additionally, major adverse cardiovascular events (MACE), myocardial infarction, stroke or transient ischaemic attack, all-cause death, all re-intervention (or re-operation), wound infection, vascular access-related major complication, walking distance, and Rutherford-classification were consented as highly relevant. Ankle-brachial-index was consented as highly practicable. CONCLUSIONS This Delphi approach of vascular experts identified three indicators as highly relevant and clinically practicable to be recommended as indicators of outcome quality in invasive PAD treatment. Among others, these consented items may help in harmonising future studies and quality benchmarking increasing their comparability, validity, and efficiency.

Rationale and methods of the IDOMENEO health outcomes of the peripheral arterial disease revascularisation study in the GermanVasc registry

BACKGROUND Atherosclerotic disease of the lower extremity arteries (PAD) remains a significant burden on global healthcare systems with increasing prevalence. Various guidelines on the diagnosis and treatment of patients with PAD are available but they often lack a sufficient evidence base for high-grade recommendations since randomized and controlled trials (RCT) remain rare or are frequently subject to conflicts of interest. This registry trial aims to evaluate the outcomes of catheter-based endovascular revascularisations vs. open-surgical endarterectomy vs. bypass surgery for symptomatic PAD on medical and patient-reported outcomes. METHODS AND DESIGN The study is a prospective non-randomized multicentre registry trial including invasive revascularisations performed in 10 000 patients treated for symptomatic PAD at 30 to 40 German vascular centres. All patients matching the inclusion criteria are consecutively included for a recruitment period of six months (between May and December 2018) or until 10 000 patients have been included in the study registry. There are three follow-up measures at three, six, and 12 months. Automated completeness and plausibility checks as well as independent site visit monitoring will be performed to assure high internal and external validity of the study data. Study endpoints include relevant major cardiovascular and limb events and patient-reported outcomes from two Delphi studies with experts in vascular medicine and registry-based research. DISCUSSION It remains unclear if results from RCT can reflect daily treatment practice. Furthermore, great costs and complexity make it challenging to accomplish high quality randomized trials in PAD treatment. Prospective registry-based studies to collect real-world evidence can help to overcome these limitations.

International Consortium of Vascular Registries Consensus Recommendations for Peripheral Revascularisation Registry Data Collection

OBJECTIVE/BACKGROUND To achieve consensus on the minimum core data set for evaluation of peripheral arterial revascularisation outcomes and enable collaboration among international registries. METHODS A modified Delphi approach was used to achieve consensus among international vascular surgeons and registry members of the International Consortium of Vascular Registries (ICVR). Variables, including definitions, from registries covering open and endovascular surgery, representing 14 countries in ICVR, were collected and analysed to define a minimum core data set and to develop an optimum data set for registries. Up to three different levels of variable specification were suggested to allow inclusion of registries with simpler versus more complex data capture, while still allowing for data aggregation based on harmonised core definitions. RESULTS Among 31 invited experts, 25 completed five Delphi rounds via internet exchange and face to face discussions. In total, 187 different items from the various registry data forms were identified for potential inclusion in the recommended data set. Ultimately, 79 items were recommended for inclusion in minimum core data sets, including 65 items in the level 1 data set, and an additional 14 items in the more specific level 2 and 3 recommended data sets. Data elements were broadly divided into (i) patient characteristics; (ii) comorbidities; (iii) current medications; (iv) lesion treated; (v) procedure; (vi) bypass; (vii) endarterectomy (viii) catheter based intervention; (ix) complications; and (x) follow up. CONCLUSION A modified Delphi study allowed 25 international vascular registry experts to achieve a consensus recommendation for a minimum core data set and an optimum data set for peripheral arterial revascularisation registries. Continued global harmonisation of registry infrastructure and definition of items will overcome limitations related to single country investigations and enhance the development of real world evidence.

Initial experience with a new quantitative assessment tool for fluorescent imaging in peripheral artery disease

BACKGROUND Perioperative evaluation in peripheral artery disease (PAD) by common vascular diagnostic tools is limited by open wounds, medial calcinosis or an altered collateral supply of the foot. Indocyanine green fluorescent imaging (ICG-FI) has recently been introduced as an alternative tool, but so far a standardized quantitative assessment of tissue perfusion in vascular surgery has not been performed for this purpose. The aim of this feasibility study was to investigate a new software for quantitative assessment of tissue perfusion in patients with PAD using indocyanine green fluorescent imaging (ICG-FI) before and after peripheral bypass grafting. PATIENTS AND METHODS Indocyanine green fluorescent imaging was performed in seven patients using the SPY Elite system before and after peripheral bypass grafting for PAD (Rutherford III-VI). Visual and quantitative evaluation of tissue perfusion was assessed in an area of low perfusion (ALP) and high perfusion (AHP), each by three independent investigators. Data assessment was performed offline using a specially customized software package (Institute for Laser Technology, University Ulm, GmbH). Slope of fluorescent intensity (SFI) was measured as time-intensity curves. Values were compared to ankle-brachial index (ABI), slope of oscillation (SOO), and time to peak (TTP) obtained from photoplethysmography (PPG). RESULTS All measurements before and after surgery were successfully performed, showing that ABI, TTP, and SOO increased significantly compared to preoperative values, all being statistically significant (P < 0.05), except for TTP (p = 0.061). Further, SFI increased significantly in both ALP and AHP (P < 0.05) and correlated considerably with ABI, TTP, and SOO (P < 0.05). CONCLUSIONS In addition to ABI and slope of oscillation (SOO), the ICG-FI technique allows visual assessment in combination with quantitative assessment of tissue perfusion in patients with PAD. Ratios related to different perfusion patterns and SFI seem to be useful tools to reduce factors disturbing ICG-FI measurements.

Open surgical treatment for postthrombotic syndrome

The postthrombotic syndrome counts as a frequent long-term complication after deep vein thrombosis with approximately 20%–50% of affected patients after deep vein thrombosis. The earliest that diagnosis of postthrombotic syndrome can be made is 6 months after deep vein thrombosis. Most patients suffer from swelling and chronic pain. In all, 5%–10% of patients may even develop venous ulcers. The complex etiology consists of limited venous drainage because of chronic occlusions and secondary insufficiencies of venous valves inducing non-physiological venous reflux. Conservative management, first of all compression therapy, is of crucial importance in treatment of postthrombotic syndrome. Endovascular and open surgical techniques can additionally be used in a small subgroup of patients. Although rarely performed, this article illuminates the open surgical techniques in treatment of postthrombotic syndrome such as venous bypass surgery, valve repair and varicose vein surgery.

Complete Ipsilateral Femoral Approach Using an Iliac Branch Device to Preserve a Sole Internal Iliac Artery After Aortic Stent-Graft Placement.

Purpose: To report implantation of an iliac branch device (IBD) for preserving antegrade blood flow to a sole internal iliac artery (IIA) via an ipsilateral approach during endovascular repair to reline an aortobi-iliac allograft. Technique: The technique is described in a 55-year-old man with an enteric fistula involving an aortobi-iliac Y-prosthesis. After complete excision, the prosthesis was replaced by an allograft. Due to rebleeding and resuturing of the graft, total stent-graft relining of the allograft was planned with preservation of the sole left IIA using an iliac side branch (ZBIS). During introduction of a 12-F sheath over the allograft’s neobifurcation to establish a femorofemoral through-and-through approach, the allograft ruptured. A compliant balloon was inflated to control the hemorrhage. The IBD was first fully deployed, followed by stent-graft relining. Consequently, stent-graft implantation in the left IIA using a crossover maneuver was no longer feasible, so a 0.035-inch super stiff wire was introduced through the IBD’s 20-F sheath. A 12-mm semi-compliant balloon was inflated in the common iliac artery above the iliac branch to act as an abutment for a 7-F sheath to run over the stiff wire into the IIA for delivery/deployment of a stent-graft. Conclusion: It is feasible to use a complete ipsilateral femoral approach for IBD implantation after aortic stent-graft placement.