Christoph Domenig

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

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

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

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

Background: We aimed to verify the accuracy of the Computational Fluid Dynamics (CFD) algorithm for blood flow reconstruction for type IIIb aortic dissection (TBAD) before and after thoracic endovascular aortic repair (TEVAR). Methods: We made 3D models of the aorta and its branches using pre- and post-operative CT data from five patients treated for TBAD. The CFD technique was used to quantify the displacement forces acting on the aortic wall in the areas of endograft, mass flow rate/velocity and wall shear stress (WSS). Calculated results were verified with ultrasonography (USG-Doppler) data. Results: CFD results indicated that the TEVAR procedure caused a 7-fold improvement in overall blood flow through the aorta (p = 0.0001), which is in line with USG-Doppler data. A comparison of CFD results and USG-Doppler data indicated no significant change in blood flow through the analysed arteries. CFD also showed a significant increase in flow rate for thoracic trunk and renal arteries, which was in accordance with USG-Doppler data (accuracy 90% and 99.9%). Moreover, we observed a significant decrease in WSS values within the whole aorta after TEVAR compared to pre-TEVAR (1.34 ± 0.20 Pa vs. 3.80 ± 0.59 Pa, respectively, p = 0.0001). This decrease was shown by a significant reduction in WSS and WSS contours in the thoracic aorta (from 3.10 ± 0.27 Pa to 1.34 ± 0.11Pa, p = 0.043) and renal arteries (from 4.40 ± 0.25 Pa to 1.50 ± 0.22 Pa p = 0.043). Conclusions: Post-operative remodelling of the aorta after TEVAR for TBAD improved hemodynamic patterns reflected by flow, velocity and WSS with an accuracy of 99%.

The aim of this paper was to report our preliminary experience in outcome, safety and mid-term results in the treatment of thoracoabdominal aortic aneurysms (TAAA) with a novel multibranchstentgraft (E-xtra DESIGN ENGINEERING, JOTEC, Germany). Eight patients (mean age 66 years, 2 female) with TAAA (Crawford type I: 2 cases, type III: 3 cases, type IV: 3 cases), mean aneurysm diameter 61 mm, growth over 5 mm per year were treated. Implantation was performed under general anesthesia and surgical exposition of the common femoral artery. Brachial access was percutaneous in 5/8 patients. Balloon-expandable (Advanta V12) bridging stent-grafts were employed and lined with self-expanding nitinol stents. All patients except type IV TAAA received a spinal drainage catheter. The device was successfully deployed in 8/8 patients. 29/32 visceral branches were engaged. One stenosed celiac trunk was left untreated without further consequences, two renal arteries which could not be cannulated were revascularized with iliorenal bypass. One patient needed surgical revision of groin hematoma, one patient suffered from permanent protopathic sensory deficit. No renal complications occurred. Since the primary implantation was deliberately kept short and amount of contrast agent was minimised, four patients needed a secondary percutaneous procedure (Palmaz stent implantation for type I endoleak, re-PTA or additional bridging stent-graft implantation for type III endoleak). The assisted primary success rate was 8/8. Mean follow-up was 18 months. Success was stable in 7/8 patients, one patient shows type V endoleak with 5mm sac expansion. No mortality or complication occurred during follow-up. The JOTEC E-xtra DESIGN ENGINEERING multibranch stent-graft is a promising new candidate for endovascular TAAA treatment with sufficient safety and efficacy. Its short delivery time suggests its use in patients with rapid aneurysm growth or high anxiety.

We present a case of carotidynia that we believe supports its classification as a distinct inflammatory disease entity. Doppler sonography and cervical magnetic resonance imaging are appropriate imaging modalities for diagnosing presumed carotidynia. Wir stellen einen Fall mit Carotidynie vor, der unseres Erachtens die Klassifikation dieser Erkrankung als eigenständige entzündliche Krankheit unterstützt. Doppler Ultraschall und Magnetresonanz der Halsregion sind geeignete bildgebende Verfahren zur Diagnose einer suspizierten Carotidynie.