Perspective or Spectacle? Teaching thoracic aortic anatomy in a mixed reality assisted educational approach- a two-armed randomized pilot study.

PURPOSE: Anatomical understanding is an important basis for medical teaching, especially in a surgical context. The interpretation of complex vascular structures via two-dimensional visualization can yet be difficult, particularly for students. The objective of this study was to investigate the feasibility of an MxR-assisted educational approach in vascular surgery undergraduate education, comparing an MxR-based teaching-intervention with CT-based material for learning and understanding the vascular morphology of the thoracic aorta. METHODS: In a prospective randomized controlled trial learning success and diagnostic skills following an MxR- vs. a CT-based intervention was investigated in 120 thoracic aortic visualizations. Secondary outcomes were motivation, system-usability as well as workload/satisfaction. Motivational factors and training-experience were also assessed. Twelve students (7 females; mean age: 23 years) were randomized into two groups undergoing educational intervention with MxR or CT. RESULTS: Evaluation of learning success showed a mean improvement of 1.17 points (max.score: 10; 95%CI: 0.36-1.97). The MxR-group has improved by a mean of 1.33 [95% CI: 0.16-2.51], against 1.0 points [95% CI: -0.71- 2.71] in the CT-group. Regarding diagnostic skills, both groups performed equally (CT-group: 58.25 ± 7.86 vs. MxR-group:58.5 ± 6.60; max. score 92.0). 11/12 participants were convinced that MxR facilitated learning of vascular morphologies. The usability of the MxR-system was rated positively, and the perceived workload was low. CONCLUSION: MxR-systems can be a valuable addition to vascular surgery education. Further evaluation of the technology in larger teaching situations are required. Especially regarding the acquisition of practical skills, the use of MxR-systems offers interesting application possibilities in surgical education.

Image-based assessment of aortoiliac aneurysm anatomical characteristics in patients from the global iliac branch study.

OBJECTIVE: Endovascular repair is the preferred treatment for aortoiliac aneurysm, with preservation of at least one internal iliac artery recommended. This study aimed to assess pre-endovascular repair anatomical characteristics of aortoiliac aneurysm in patients from the Global Iliac Branch Study (GIBS, NCT05607277) to enhance selection criteria for iliac branch devices (IBD) and improve long-term outcomes. METHODS: Pre-treatment CT scans of 297 GIBS patients undergoing endovascular aneurysm repair were analyzed. Measurements included total iliac artery length, common iliac artery length, tortuosity index, common iliac artery splay angle, internal iliac artery stenosis, calcification score, and diameters in the device's landing zone. Statistical tests assessed differences in anatomical measurements and IBD-mediated internal iliac artery preservation. RESULTS: Left total iliac artery length was shorter than right (6.7 mm, P = .0019); right common iliac artery less tortuous (P = .0145). Males exhibited greater tortuosity in the left total iliac artery (P = .0475) and larger diameter in left internal iliac artery's landing zone (P = .0453). Preservation was more common on right (158 unilateral, 34 bilateral) than left (105 unilateral, 34 bilateral). There were 192 right-sided and 139 left-sided IBDs, with 318 IBDs in males and 13 in females. CONCLUSION: This study provides comprehensive pre-treatment iliac anatomy analysis in patients undergoing endovascular repair with IBDs, highlighting differences between sides and sexes. These findings could refine patient selection for IBD placement, potentially enhancing outcomes in aortoiliac aneurysm treatment. However, the limited number of females in the study underscores the need for further research to generalize findings across genders.

Clinically compatible subject-specific dynamic parallel transmit pulse design for homogeneous fat saturation and water-excitation at 7T: Proof-of-concept for CEST MRI of the brain.

PURPOSE: To evaluate the benefits and challenges of dynamic parallel transmit (pTx) pulses for fat saturation (FS) and water-excitation (WE), in the context of CEST MRI. METHODS: "Universal" kT -points (for FS) and spiral non-selective (for WE) trajectories were optimized offline for flip angle (FA) homogeneity. Routines to optimize the pulse shape online, based on the subject's fields maps, were implemented (target FA of 110°/0° for FS, 0°/5° for WE at fat/water frequencies). The pulses were inserted in a CEST sequence with a pTx readout. The different fat suppression schemes and their effects on CEST contrasts were compared in 12 volunteers at 7T. RESULTS: With a 25%-shorter pulse duration, pTx FS largely improved the FA homogeneity (root-mean-square-error (RMSE) = 12.3° vs. 53.4° with circularly-polarized mode, at the fat frequency). However, the spectral selectivity was degraded mainly in the cerebellum and close to the sinuses (RMSE = 5.8° vs. 0.2° at the water frequency). Similarly, pTx WE showed a trade-off between FA homogeneity and spectral selectivity compared to pTx non-selective pulses (RMSE = 0.9° and 1.1° at the fat and water frequencies, vs. 4.6° and 0.5°). In the brain, CEST metrics were reduced by up to 31.9% at -3.3 ppm with pTx FS, suggesting a mitigated lipid-induced bias. CONCLUSION: This clinically compatible implementation of dynamic pTx pulses improved the fat suppression homogeneity at 7T taking into account the subject-specific B0 heterogeneities online. This study highlights the lipid-induced biases on the CEST z-spectrum. The results are promising for body applications where B0 heterogeneities and fat are more substantial.

DeepCEST 7 T: Fast and homogeneous mapping of 7 T CEST MRI parameters and their uncertainty quantification.

PURPOSE: In this work, we investigated the ability of neural networks to rapidly and robustly predict Lorentzian parameters of multi-pool CEST MRI spectra at 7 T with corresponding uncertainty maps to make them quickly and easily available for routine clinical use. METHODS: We developed a deepCEST 7 T approach that generates CEST contrasts from just 1 scan with robustness against B1 inhomogeneities. The input data for a neural feed-forward network consisted of 7 T in vivo uncorrected Z-spectra of a single B1 level, and a B1 map. The 7 T raw data were acquired using a 3D snapshot gradient echo multiple interleaved mode saturation CEST sequence. These inputs were mapped voxel-wise to target data consisting of Lorentzian amplitudes generated conventionally by 5-pool Lorentzian fitting of normalized, denoised, B0 - and B1 -corrected Z-spectra. The deepCEST network was trained with Gaussian negative log-likelihood loss, providing an uncertainty quantification in addition to the Lorentzian amplitudes. RESULTS: The deepCEST 7 T network provides fast and accurate prediction of all Lorentzian parameters also when only a single B1 level is used. The prediction was highly accurate with respect to the Lorentzian fit amplitudes, and both healthy tissues and hyperintensities in tumor areas are predicted with a low uncertainty. In corrupted cases, high uncertainty indicated wrong predictions reliably. CONCLUSION: The proposed deepCEST 7 T approach reduces scan time by 50% to now 6:42 min, but still delivers both B0 - and B1 -corrected homogeneous CEST contrasts along with an uncertainty map, which can increase diagnostic confidence. Multiple accurate 7 T CEST contrasts are delivered within seconds.

Snapshot CEST++: Advancing rapid whole-brain APTw-CEST MRI at 3 T.

APTw CEST MRI suffers from long preparation times and consequently long acquisition times (~5 min). Recently, a consensus on the preparation module for clinical APTw CEST at 3 T was found in the community, and we present a fast whole-brain APTw CEST MRI sequence following this consensus preparation of pulsed RF irradiation of 2 s duration at 90% RF duty-cycle and a B1,rms of 2 µT. After optimization of the snapshot CEST approach for APTw imaging regarding flip angle, voxel size and frequency offset sampling, we extend it by undersampled GRE acquisition and compressed sensing reconstruction. This allows 2 mm isotropic whole-brain APTw imaging for clinical research at 3 T below 2 min. With this sequence, a fast snapshot APTw imaging method is now available for larger clinical studies of brain tumors.

7 tricks for 7 T CEST: Improving the reproducibility of multipool evaluation provides insights into the effects of age and the early stages of Parkinson's disease.

The objective of the current study was to optimize the postprocessing pipeline of 7 T chemical exchange saturation transfer (CEST) imaging for reproducibility and to prove this optimization for the detection of age differences and differences between patients with Parkinson's disease versus normal subjects. The following 7 T CEST MRI experiments were analyzed: repeated measurements of a healthy subject, subjects of two age cohorts (14 older, seven younger subjects), and measurements of 12 patients with Parkinson's disease. A slab-selective, B 1 + -homogeneous parallel transmit protocol was used. The postprocessing, consisting of motion correction, smoothing, B 0 -correction, normalization, denoising, B 1 + -correction and Lorentzian fitting, was optimized regarding the intrasubject and intersubject coefficient of variation (CoV) of the amplitudes of the amide pool and the aliphatic relayed nuclear Overhauser effect (rNOE) pool within the brain. Seven "tricks" for postprocessing accomplished an improvement of the mean voxel CoV of the amide pool and the aliphatic rNOE pool amplitudes of less than 5% and 3%, respectively. These postprocessing steps are: motion correction with interpolation of the motion of low-signal offsets (1) using the amide pool frequency offset image as reference (2), normalization of the Z-spectrum using the outermost saturated measurements (3), B 0 correction of the Z-spectrum with moderate spline smoothing (4), denoising using principal component analysis preserving the 11 highest intensity components (5), B 1 + correction using a linear fit (6) and Lorentzian fitting using the five-pool fit model (7). With the optimized postprocessing pipeline, a significant age effect in the amide pool can be detected. Additionally, for the first time, an aliphatic rNOE contrast between subjects with Parkinson's disease and age-matched healthy controls in the substantia nigra is detected. We propose an optimized postprocessing pipeline for CEST multipool evaluation. It is shown that by the use of these seven "tricks", the reproducibility and, thus, the statistical power of a CEST measurement, can be greatly improved and subtle changes can be detected.

Linear projection-based chemical exchange saturation transfer parameter estimation.

Isolated evaluation of multiparametric in vivo chemical exchange saturation transfer (CEST) MRI often requires complex computational processing for both correction of B0 and B1 inhomogeneity and contrast generation. For that, sufficiently densely sampled Z-spectra need to be acquired. The list of acquired frequency offsets largely determines the total CEST acquisition time, while potentially representing redundant information. In this work, a linear projection-based multiparametric CEST evaluation method is introduced that offers fast B0 and B1 inhomogeneity correction, contrast generation and feature selection for CEST data, enabling reduction of the overall measurement time. To that end, CEST data acquired at 7 T in six healthy subjects and in one brain tumor patient were conventionally evaluated by interpolation-based inhomogeneity correction and Lorentzian curve fitting. Linear regression was used to obtain coefficient vectors that directly map uncorrected data to corrected Lorentzian target parameters. L1-regularization was applied to find subsets of the originally acquired CEST measurements that still allow for such a linear projection mapping. The linear projection method allows fast and interpretable mapping from acquired raw data to contrast parameters of interest, generalizing from healthy subject training data to unseen healthy test data and to the tumor patient dataset. The L1-regularization method shows that a fraction of the acquired CEST measurements is sufficient to preserve tissue contrasts, offering up to a 2.8-fold reduction of scan time. Similar observations as for the 7-T data can be made for data from a clinical 3-T scanner. Being a fast and interpretable computation step, the proposed method is complementary to neural networks that have recently been employed for similar purposes. The scan time acceleration offered by the L1-regularization ("CEST-LASSO") constitutes a step towards better applicability of multiparametric CEST protocols in a clinical context.

A 10-Year Single-Center Experience With the GORE TAG Conformable Thoracic Stent Graft in the Treatment of Thoracic Aortic Disease.

OBJECTIVE: The aim of this study was to report 10-year real-world single-center experience with the GORE TAG conformable thoracic aortic graft (CTAG), focusing on rupture-free survival, aortic-related reintervention, and device-related complications during midterm and long-term follow-up (FU). METHODS: This retrospective study analyzes results of thoracic endovascular aortic repair (TEVAR) performed between January 2009 and December 2018. Out of 419 TEVAR procedures within this period, 194 patients (male 57.2%, 111/194), with a mean age of 65 ± 13 years, were treated with the CTAG device. Indication for TEVAR was a thoracic aortic aneurysm in 24.7% (48/194), type B aortic dissection in 32.5% (63/194), penetrating aortic ulcer 15.5% (30/194), and miscellaneous 27.3% (53/194). Emergently were operated 43.8% (85/194) patients. Median follow-up (FU) including computed tomography imaging was 43.5 months (Q1-Q3: 8.6-67.0) and was completed in 91.2% (177/194) of patients. RESULTS: Overall survival rates were 75.8% (95% confidence interval [CI] = [0.76-0.70]) and 56.6% (95% CI = [0.57-0.50]) at 12 and 60 months, respectively. Cumulative incidence for aortic rupture was 11.9% (95% CI = [0.07-0.17]) at 60 and 90 months, respectively. Cumulative incidence for aortic-related reintervention was 27.5% (95% CI = [0.21-0.34]) at 60 and 90 months. Cumulative incidence for migration was 2.8% (95% CI = [0.004-0.05]) and 3.9% (95% CI = [0.007-0.07]) at 60 and 90 months, respectively. New endograft infections or material fatigue were not observed. CONCLUSIONS: The herein reported 10-year real-world single-center experience with the CTAG observed favorable long-term outcome. Thus, the device demonstrates appropriate persistent safety, efficacy, and clinical durability up to long-term FU in the treatment of diverse thoracic aortic pathologies.

Late Endograft Migration After Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-analysis.

PURPOSE: The objective of this systematic review was to report the cumulative incidence of endograft migration (EM), as well as the morbidity, reintervention rates, and mortality related to EM. This study aimed to provide evidence-based data on patient-relevant sequelae of EM after thoracic endovascular aortic repair (TEVAR) performed using contemporary aortic endografts. MATERIALS AND METHODS: A systematic electronic search of literature in MEDLINE (via PubMed), Web of Science, and Cochrane Central Register of Controlled Trials was performed. The pooled synthesis of outcomes was performed using the inverse variance method. RESULTS: Seven prospective non-randomized and 4 retrospective studies, including a total of 1783 patients presenting 70 EMs, were considered for the quantitative analysis. The pooled rate of EM was 4% (95% CI, 2%-7%; range, 0.2%-11%; I2=82%); pooled morbidity rate was 31% (95% CI, 12%-59%; range, 0%-100%; I2=64%) and pooled reintervention rate was 32% (95% CI, 15%-56%; range, 0%-100%; I2=55%). The pooled mortality rate due to EM was 5% (95% CI, 1%-21%; range, 0%-40%; I2=24%). CONCLUSION: For the first time, this meta-analysis provides pooled reference estimates of EM after TEVAR. Thus, the results hold the potential to further characterize EM after TEVAR. The clinical relevance of EM is underlined by its association with high rates of endoleak-related morbidity, reintervention, and mortality. Close standardized surveillance after TEVAR for early detection of EM and prophylaxis of its sequelae is essential.

Males and females with first episode psychosis present distinct profiles of social cognition and metacognition.

Deficits in social cognition and metacognition impact the course of psychosis. Sex differences in social cognition and metacognition could explain heterogeneity in psychosis. 174 (58 females) patients with first-episode psychosis completed a clinical, neuropsychological, social cognitive, and metacognitive assessment. Subsequent latent profile analysis split by sex yielded two clusters common to both sexes (a Homogeneous group, 53% and 79.3%, and an Indecisive group, 18.3% and 8.6% of males and females, respectively), a specific male profile characterized by presenting jumping to conclusions (28.7%) and a specific female profile characterized by cognitive biases (12.1%). Males and females in the homogeneous profile seem to have a more benign course of illness. Males with jumping to conclusions had more clinical symptoms and more neuropsychological deficits. Females with cognitive biases were younger and had lower self-esteem. These results suggest that males and females may benefit from specific targeted treatment and highlights the need to consider sex when planning interventions.

Outcome Analysis and Risk Factors for Perioperative Myocardial Ischemia After Elective Aortic Surgery.

BACKGROUND: Perioperative myocardial ischemia (PMI) after non-cardiac surgery remains a serious postoperative complication. This study analyzed the risk factors and outcomes of patients who suffered from PMI after elective aortic surgery. PATIENTS AND METHODS: Data from 863 patients who underwent elective aortic surgery for aneurysms or Leriche syndrome were retrospectively analysed with regard to PMI. The diagnosis of PMI was based on a positive serum troponin diagnostic test. According to the clinical signs and symptoms, the patients with PMI were divided into two groups: symptomatic and asymptomatic patients. Comorbidities, preoperative medication, intraoperative parameters, postoperative complications, mortality, length of intensive care stay and hospitalisation, as well as the long-term follow-up, were compared in a matched-pair analysis (1:3) with patients without PMI. Logistic regression analyses were performed to identify independent risk factors for PMI. RESULTS: Thirty-two patients with PMI were identified. Cardiac comorbidities (previous myocardial ischemia, P = 0.0099; left ventricular systolic dysfunction, P = 0.0429), ASA score ≥III (P = 0.0114) and preoperative elevated creatinine (P = 0.0194) were more common in patients who suffered PMI. The regression analysis confirmed that peripheral artery disease and prolonged operative duration >180 min are significant predictors of PMI. Surgical complications (wound healing deficit, P = 0.0027; rate of secondary interventions during primary admission, P = 0.0057) and medical complications (pneumonia, P = 0.0002; renal dysfunction, P = 0.0041) were more common in patients with PMI compared to the control group. Patients who suffered PMI remained in intensive care for a significantly longer period (P = 0.0001) and were also hospitalized for longer (P = 0.0001) than the control group. The long-term survival of patients who suffered PMI after aortic surgery was significantly worse than the control group (P < 0.0001, median 53 vs. 84 months), independent of clinical ischemia-associated symptoms. CONCLUSIONS: PMI after aortic surgery not only affects long-term survival, but also correlates with worsening of surgical outcome. Thus, meticulous preoperative risk stratification is required for high-risk patients, together with routine postoperative monitoring of troponin levels after aortic surgery.

[Diagnosis and Management of Perioperative Myocardial Ischemia after Elective Aortic Aneurysm Surgery]. / Diagnostik und Management der perioperativen Myokardischämie im Rahmen elektiver Eingriffe bei Aortenaneurysmen.

INTRODUCTION: Perioperative myocardial ischemia (PMI) is a serious postoperative complication. Aortic operations represent an especially high-risk surgery concerning cardiac complications. This aim of this study was to analyse the clinical features of PMI after elective aortic aneurysm surgery. PATIENTS AND METHODS: This study is a retrospective analysis of 863 patients who underwent elective aortic aneurysm surgery between 2005 and 2012 in the Department of Vascular and Endovascular Surgery of Heidelberg University Hospital with regard to PMI. The PMI diagnosis was based on a positive serum troponin diagnostic test. We evaluated the clinical course, time point of the diagnosis and features of diagnostics to characterise PMI. Moreover, we analysed the treatment options and management of the patients' discharge. RESULTS: Thirty-one patients (3.6% of 863) with PMI after elective aortic aneurysm surgery were identified. Of these, 21 patients (67.7%) underwent open surgery and 10 patients (32.3%) received endovascular treatment. PMI was diagnosed in 24 patients (77%) during the first 3 days. More than half of these patients (16/31) were clinically asymptomatic. Electrocardiogram did not show pathological findings in 24 cases (77.4%). The first troponin measurement was not elevated in eight patients (25.8%). Drug therapy alone was used in 17 cases (54.8%) of PMI, coronary catheterisation was performed in 12 patients (38.7%) and two patients (6.5%) received aortocoronary bypass. Fourteen patients (45.1%) were discharged home and another 14 patients (44.1%) were transferred to another hospital or to a rehabilitation institution. Two patients died because of multi-organ failure. CONCLUSION: PMI is not a rare complication after elective aortic surgery. The diagnosis of PMI can be challenging because of occult symptoms especially in a perioperative setting. Due to the potentially serious consequences, cardiac enzyme diagnostics should be initiated immediately if there is suspicion of PMI or routinely in defined at-risk patients after aortic surgery.

[Discuss Many to Benefit More - Five-Year Analysis of a Multidisciplinary Aortic Board]. / Discuss Many to Benefit More ­ Fünf-Jahres-Analyse eines interdisziplinären Aortenkolloquium.

BACKGROUND: Multidisciplinary aortic boards (mAB) are a valuable tool for decision making in patients with aortic pathologies. The aim of this study was to evaluate the mAB of a maximum care hospital with regards to total patient volume and discipline-specific presentations. Furthermore, the indications for conservative/surgical treatment and the patients' allocation were reviewed. METHODS: A retrospective analysis was performed of all patients discussed in the mAB of Heidelberg University Hospital (Department of Vascular and Endovascular Surgery [VS]/Department of Cardiac Surgery [CS]/Department of Radiology), between 01/2014 and 12/2018. RESULTS: Within a five-year period, 344 patients (median of 71 patients/year) were discussed. Of those, 262 (76%) were presented by VS, mostly recruited from the outpatient sector. Another 63 cases (18%), originated from CS and 19 patients (6%) from other disciplines. An indication for surgical treatment was defined in 153 of 344 patients (45%), whereas 191 of 344 cases (55%) were treated in a conservative fashion. Procedures performed by VS were indicated in 85/153 (55%) cases, including 25% (22/85) of non-VS-patients. Procedures performed by CS were indicated in 68/153 (45%) cases containing 84% (57/68) of non-CS-patients. Despite a dedicated indication for surgery, 59/153 patients (39%) did not receive the recommended therapy. CONCLUSION: mAB maintenance is highly dependent on the outpatient sector. With respect to patient selection, the mAB has an important filter function towards conservative treatment. The nearly balanced distribution between VS and CS underlines the importance of a multidisciplinary approach to aortic surgery. Given the relevant number of untreated patients, a central management office with an in-hospital registry seems crucial in order to improve mAB performance.

Midterm single-center results after endovascular aneurysm sealing reveal a high rate of stent graft migration, secondary aneurysm ruptures, and device-related reinterventions.

OBJECTIVE: To report procedural results and mid-term follow-up outcomes of patients treated with endovascular aneurysm sealing (EVAS) for abdominal aortic disease. METHODS: In this retrospective observational study, all patients treated with EVAS between March 2013 and January 2018 for abdominal aortic aneurysm (AAA) or abdominal penetrating aortic ulcer were included. The datasets included demographics, aneurysm morphology, and procedural and clinical surveillance outcomes. Furthermore, patients treated within the original instructions for use (IFU-group) were compared with patients treated outside the IFU (non-IFU-group) with regard to survival, reintervention-free survival, freedom from type I endoleak, and freedom from stent graft migration. RESULTS: Seventy patients were included (67 male; median age, 72.5 years). Sixty-five patients were treated for AAA and 5 patients for abdominal penetrating aortic ulcer. Sixty-nine cases were treated electively (98.6%). Technical success was achieved in 68 cases (97.1%). The median clinical follow-up was 50.5 months (interquartile range, 29.3-62.7 months) with a median computed tomography angiographic follow-up of 38.5 months (interquartile range, 17.1-60.2 months). There were five deaths during the study period (7.1%), four of which were aneurysm related (5.7%). Five secondary AAA ruptures were detected (7.1%). Overall, 25 of 70 patients (35.7%) underwent 35 reinterventions, mostly owing to thrombotic complications (18.6%), stent graft migration (17.1%), and type I endoleak (12.9%). Fifteen patients were treated outside of the IFU (non-IFU-group) (21.4%). The estimated reintervention-free survival for the entire cohort at 30 days and 1, 3, and 5 years was 94.3%, 88.5%, 72%, and 56.9%, respectively. Freedom from stent graft migration at 1, 3, and 5 years was 98.6%, 82.0%, and 47.3%, respectively. The estimated freedom from type I endoleak at 30 days and 1, 3, and 5 years in the IFU-group was 100%, 100%, 94.9% and, 91.1% and significantly different when compared with the non-IFU-group with 79.5%, 72.2%, 72.2%, and 72.2% (P = .012). CONCLUSIONS: Although the technical and initial results were satisfying, the mid-term results were disappointing. The enforcement of a close follow-up protocol for all patients treated with EVAS, especially vigilant for stent graft migration to prevent secondary type I endoleak and rupture, is strongly recommended.

Thoracic Endografting for Aortic Occlusion after Coarctation Surgery.

Acute occlusion of the descending thoracic aorta (DTA) is rare and associated with high morbidity and mortality. In the case described here, rescue thoracic endovascular aortic repair (TEVAR) was successful in a 59-year-old man with acute occlusion of the DTA accompanied by lower body hypoperfusion after two previous open repairs for aortic coarctation.

Outcomes of thoracic endovascular aortic repair in thoracic aortic aneurysm and penetrating aortic ulcer using the Conformable Gore TAG within and outside the instructions for use.

OBJECTIVE: To describe the outcome of thoracic endovascular aortic repair (TEVAR) in thoracic aortic aneurysm and penetrating aortic ulcer with respect to instructions for use status. METHODS: Between October 2009 and September 2017, a total of 532 patients underwent TEVAR; of which 195 have been treated using the Conformable GORE® TAG® thoracic endoprosthesis (CTAG). Fifty-six patients of this cohort underwent TEVAR for thoracic aortic aneurysm/penetrating aortic ulcer using the CTAG. Depending on the preoperative computed tomography angiography findings, patients were classified as inside or outside the device's instructions for use. All inside instruction for use patients underwent postoperative reclassification regarding the instructions for use status. Study endpoints included TEVAR-related reintervention, exclusion of the pathology (endoleak type I/III), TEVAR-related mortality, and graft-related serious adverse events. The median duration of follow-up was 29.7 months (range: 0-109.4 months). RESULTS: Of the 56 patients, 17 were primarily classified as outside instruction for use, and in additional 13 patients, TEVAR was performed outside instruction for use, leading to 30 outside instruction for use patients (53.6%). Twenty-six patients (46.4%) were treated inside instruction for use. Reintervention-free survival was lower in outside instruction for use patients (P = 0.016) with a hazard ratio of 9.74 (confidence interval 1.2-80.2; P = 0.034) for TEVAR-related reintervention. With respect to endoleak type I/III, relevant difference was detected between inside/outside instruction for use status (P = 0.012). The serious adverse event rate was 30.4%, mainly in outside instruction for use patients (P = 0.004). Logistic regression analysis indicated an association between graft-related serious adverse event/instructions for use status (odds ratio 6.11; confidence interval 1.6-30.06; P = 0.012). In-hospital death was seen more frequently in outside instruction for use patients (P = 0.12) as was procedure-related death (log-rank test: P = 0.21). CONCLUSION: TEVAR for thoracic aortic aneurysm/penetrating aortic ulcer is frequently performed outside instruction for use despite preoperative inside instruction for use eligibility, leading to important consequences for technical/clinical outcome. Instructions for use adherence in TEVAR should be of interest for further large-scale studies.

Isolated femoral artery revascularisation with or without iliac inflow improvement - a less invasive surgical option in critical limb ischemia.

Background: Isolated femoral artery revascularisation (iFAR) represents a well-established surgical method in the treatment of peripheral arterial disease (PAD) involving common femoral artery disease. Data for iFAR in multilevel PAD are inconsistent, particularly in patients with critical limb ischemia (CLI). The aim of the study was to evaluate the outcome of iFAR in CLI regarding major amputation and reintervention and to identify associated risk factors for this outcome. Patients and methods: The data used have been derived from the German Registry of Firstline Treatment in Critical Limb Ischemia (CRITISCH). A total of 1200 patients were enrolled in 27 vascular centres. This sub-analysis included patients, which were treated with iFAR with/without concomitant iliac intervention. For detection of risk factors for the combined endpoint of major amputation and/or reintervention, selection of variables for multiple regression was conducted using stepwise forward/backward selection by Akaike's information criterion. Results: 95 patients were included (mean age: 72 years ± 10.82; 64.2% male). Of those, 32 (33.7%) participants reached the combined endpoint. Risk factor analysis revealed continued tobacco use (odds ratio [OR] 2.316, confidence interval [CI] 0.832-6.674), TASC D-lesion (OR: 2.293, CI: 0.869-6.261) and previous vascular intervention in the trial leg (OR: 2.720, CI: 1.037-7.381) to be associated with reaching the combined endpoint. Conclusions: iFAR provides a reasonable, surgical option to treat CLI. Lesion length (TASC D) seems to have a negative impact on outcome. Further research is required to better define the future role of iFAR for combined femoro-popliteal lesions in CLI - best in terms of a randomised controlled trial.

Evaluation of Anti-Biofilm Activity of Mouthrinses Containing Tannic Acid or Chitosan on Dentin In Situ.

In contrast to enamel, dentin surfaces have been rarely used as substrates for studies evaluating the effects of experimental rinsing solutions on oral biofilm formation. The aim of the present in situ study was to investigate the effects of tannic acid and chitosan on 48-h biofilm formation on dentin surfaces. Biofilm was formed intraorally on dentin specimens, while six subjects rinsed with experimental solutions containing tannic acid, chitosan and water as negative or chlorhexidine as positive control. After 48 h of biofilm formation, specimens were evaluated for biofilm coverage and for viability of bacteria by fluorescence and scanning electron microscopy. In addition, saliva samples were collected after rinsing and analyzed by fluorescence (five subjects) and transmission electron microscopy (two subjects) in order to investigate the antibacterial effect on bacteria in a planktonic state and to visualize effects of the rinsing agents on salivary proteins. After rinsing with water, dentin specimens were covered by a multiple-layered biofilm with predominantly vital bacteria. In contrast, chlorhexidine led to dentin surfaces covered only by few and avital bacteria. By rinsing with tannic acid both strong anti-adherent and antibacterial effects were observed, but the effects declined in a time-dependent manner. Transmission electron micrographs of salivary samples indicated that aggregation of proteins and bacteria might explain the antiadhesion effects of tannic acid. Chitosan showed antibacterial effects on bacteria in saliva, while biofilm viability was only slightly reduced and no effects on bacterial adherence on dentin were observed, despite proteins being aggregated in saliva after rinsing with chitosan. Tannic acid is a promising anti-biofilm agent even on dentin surfaces, while rinsing with chitosan could not sufficiently prevent biofilm formation on dentin.

[Effects of an In-House Antibiotic Stewardship Initiative on Diagnosis and Management of Community-Acquired Pneumonia in Childhood and Adolescence]. / Ergebnisse der Einführung eines Antibiotic-Stewardship-Programms im stationären Bereich am Beispiel der ambulant erworbenen Pneumonie des Kindes- und Jugendalters.

BACKGROUND: Pediatric community-acquired pneumonia (pCAP) often leads to prescription of antibiotics and hospital admission of children. Unfortunately, adherence to diagnosis and treatment guidelines is inconsistent, and misuse of antibiotics may occur. Antimicrobial stewardship interventions, which were started in many hospitals during the last decade, can optimize management of pCAP without negative patient outcomes. OBJECTIVES: The objective of this retrospective analysis was to assess the influence of a newly implemented in-house pediatric antibiotic stewardship (ABS) initiative on guideline adherence and treatment quality. MATERIALS AND METHODS: Retrospective, patients' file-based analysis of the effects of an ABS initiative in a pediatric university hospital from January 2017 until March 2020. ABS initiative included creation of a local pCAP guideline for hospitalized children aged 90 days - 18 years, periodic training and continuous ABS support. RESULTS: A total of 230 patients with pCAP were included (145 before and 85 after intervention). Implementation of the ABS program led to reduction of antibiotics prescription without clear indication from 26 % to 10 % (p < 0.05). The inappropriate use of antibiotics decreased from 64 % to 27 % (p < 0.05), the rate of incorrect doses declined from 17 % to 10 % (p < 0.05) and the mean duration of antibiotic treatment declined from 10 to 7 days (p < 0.05). There were no differences between the two groups regarding length of stay, treatment failure or readmissions for respiratory infection. CONCLUSIONS: Pediatric antibiotic stewardship is an appropriate and safe method, and is beneficial to hospitalized patients with pCAP. Application of ABS programs may increase adherence to clinical guidelines and improve appropriate antimicrobial use without negative impact on patient outcomes. Multicenter follow-up studies are needed to clarify long-term effects of ABS programs.

Outcome analysis and risk factors for postoperative colonic ischaemia after aortic surgery.

PURPOSE: Colonic ischaemia (CI) represents a serious complication after aortic surgery. This study aimed to analyse risk factors and outcome of patients suffering from postoperative CI. METHODS: Data of 1404 patients who underwent aortic surgery were retrospectively analysed regarding CI occurrence. Co-morbidities, procedural parameters, colon blood supply, procedure-related morbidity and mortality as well as survival during follow-up (FU) were compared with patients without CI using matched-pair analysis (1:3). RESULTS: Thirty-five patients (2.4%) with CI were identified. Cardiovascular, pulmonary and renal comorbidity were more common in CI patients. Operation time was longer (283 ± 22 vs. 188 ± 7 min, p < 0.0001) and blood loss was higher (2174 ± 396 vs. 1319 ± 108 ml, p = 0.0049) in the CI group. Patients with ruptured abdominal aortic aneurysm (AAA) showed a higher rate of CI compared to patients with intact AAA (5.4 vs. 1.9%, p = 0.0177). CI was predominantly diagnosed by endoscopy (26/35), generally within the first 4 postoperative days (20/35). Twenty-eight patients underwent surgery, all finalised with stoma creation. Postoperative bilateral occlusion and/or relevant stenosis of hypogastric arteries were more frequent in CI patients (57.8 vs. 20.8%, p = 0.0273). In-hospital mortality was increased in the CI group (26.7 vs. 2.9%, p < 0.0001). Survival was significantly reduced in CI patients (median: 28.2 months vs. 104.1 months, p < 0.0001). CONCLUSION: CI after aortic surgery is associated with considerable perioperative sequelae and reduced survival. Especially in patients at risk, such as those with rAAA, complicated intraoperative course, severe cardiovascular morbidity and/or perioperative deterioration of the hypogastric perfusion, vigilant postoperative multimodal monitoring is required in order to initiate diagnosis and treatment.