Technical and clinical success analysis of transarterial embolization therapy in type II endoleaks following endovascular aortic repair.

This single-center study investigated the safety and efficacy of transarterial embolization of type II endoleaks for expanding aneurysm sacs following endovascular aortic repair (EVAR).36 patients (33 men, 75.9±6.6 years) underwent a total of 50 endovascular procedures for type II endoleak embolization between 2008 and 2023. Analyses included the assessment of patient risk profiles, aneurysm morphology, and endoleak characteristics. Outcome parameters comprised the technical success (i.e., complete lack of blood flow in the previously perfused aneurysm sac) and complication rates, while clinical success was defined as the absence of endoleak persistence or recurrence and freedom from aneurysm enlargement > 0.5 cm over the follow-up period.Transarterial embolization was technically successful in 84% of procedures with a complication rate of 2%. Most interventions were coil-based (72%), while a small number relied solely on liquid embolic agents (14%). Absence of a persisting endoleak in the earliest follow-up could be demonstrated in 75.6% of cases, whereas the absence rate for endoleak recurrence was substantially lower (46.3%). No aneurysm enlargement > 0.5 cm during follow-up was ascertained after 73.2% of interventions.Transarterial embolization represents a safe treatment for type II endoleaks after EVAR. While embolization was moderately effective in preventing further expansion of aneurysms due to endoleak recurrence, most procedures were successful in permanently eliminating the targeted feeder vessels. · Transarterial embolization of type II endoleaks has a high technical success rate.. · The emergence of new feeder vessels may necessitate multiple procedures over time.. · Patient risk profiles did not factor into the clinical outcome.. · Krompaß K, Grunz JP, Augustin AM et al. Technical and clinical success analysis of transarterial embolization therapy in type II endoleaks following endovascular aortic repair. Fortschr Röntgenstr 2024; DOI 10.1055/a-2384-4601.

Bridging Visual-Spatial Ability and Skill Performance: The Impact of Perceived Quality of a Practical Seminar in Interventional Radiology Education.

BACKGROUND: Medical education integrates skills training and simulation to prepare students for clinical tasks. A seminar on interventional radiology was restructured to include specific practical training utilizing a 3D-catheter model. We aimed to investigate the complex interplay between student evaluations, their visual-spatial ability and practical performance. METHODS: The seminar comprised a short plenary introduction followed by 3 practical training units. Students were tested for their visual-spatial ability and their catheter insertion performance. Students rated the seminar and their interest in the subject. Data were subjected to descriptive, factorial, regression, and moderating analysis. RESULTS: A total of 141 medical students enrolled in the seminar. They attributed a high didactic and practical quality and expressed great interest in the subject. Male students outperformed females in the cube perspective test. In the practical examination, males needed significantly less time on average (57.9 s) compared to females (73.1 s). However, there were no significant differences in the performance score, with a maximum of 5 attainable points: males 4.61 and females 4.51. The seminar evaluation explained a large portion of the variance (48.6%) in students' interest in the subject. There was a moderating role of practical quality (ß = 0.12, P < .05) on the link between the cube perspective test and the practical examination: rated high practical quality could partly compensate for low cube perspective scores, enhancing performance in the practical examination. CONCLUSIONS: Well-designed practical courses and a perceived high teaching quality may assist students with deficits in visual-spatial ability to acquire clinical-practical skills. Such initiatives not only enhance learning outcomes across diverse student groups but also stimulate interest in specialized fields like interventional radiology, thereby potentially guiding future career paths in medicine.

Endovascular therapy in intermittent claudication: Impact of IVUS guidance on treatment decisions.

Conservative therapy is favored over revascularization for patients with peripheral arterial disease (PAD) and intermittent claudication (IC) owing to the better long-term results. The adjunctive use of intravascular ultrasound (IVUS) significantly improves endovascular therapy. However, data on IVUS and IC is scarce. Therefore, the aim of this investigation was to determine the safety and efficacy of IVUS in patients with IC and to evaluate discrepancies compared to angiography and potential consequences for treatment.This was a single-center prospective cohort study. Twenty patients with IC and femoropopliteal disease eligible for endovascular therapy were enrolled. Procedural data and discrepancies between IVUS and angiography were recorded.In total, 30 lesions were treated. IVUS-based measurements yielded substantially higher reference vessel diameters (RVD) and lesion lengths compared to DSA alone (RVD: 5.37 ± 0.71 mm vs. 4.74 ± 0.63 mm, p<.001, lesion length: 62.4 ± 41.4 mm vs. 42.18 ± 30.2 mm, p<.001). In 24 of 30 lesions (80%), a significant discrepancy in RVD (defined as difference >0.5 mm) and lesion length (defined as >20 mm) was determined between IVUS and standard DSA. Subsequently, IVUS assessment led to upsizing in 14 of 30 lesions (47%) and downsizing in 3 of 30 lesions (10%). On average, IVUS led to the selection of considerably larger balloons (5.25 ± 0.62 vs. 4.74 ± 0.63, p<.004) and device length (78.97 ± 44.19 mm vs. 42.18 ± 30.2, p<.001). Serious adverse events did not occur. Technical success was achieved in all cases.IVUS is safe and provides advantages regarding the evaluation of IC by depicting RVD and lesion length more reliably than standard DSA. More precise assessment of lesions resulted in the use of significantly larger devices. · The safety and efficacy of IVUS are confirmed for the distinct cohort of patients with IC.. · IVUS provides advantages for the evaluation of IC by depicting RVD and lesion length more reliably than standard DSA.. · More precise assessment of stenoses resulted in the selection of significantly larger devices, hence suggesting substantial clinical impact.. Hartung V, Augustin AM, Gruschwitz P et al. Endovascular therapy in intermittent claudication: Impact of IVUS guidance on treatment decisions. Fortschr Röntgenstr 2024; DOI 10.1055/a-2379-8857.

Ultra-high Versus Standard Resolution Photon-Counting Detector CT Angiography for Imaging of Femoral Stents in a Cadaveric Perfusion Model.

BACKGROUND AND AIMS: The aim of this study was to investigate the imaging performance and quality differences of PCD-CT in standard resolution mode (SR) versus ultra-high resolution mode (UHR) in the lower extremity runoff of dose-matched CTAs in a human cadaveric model. METHODS: Extracorporeal perfusion of the upper leg was established in one fresh-frozen human cadaver via inguinal and popliteal accesses using a peristaltic pump. Seven peripheral stents were deployed in the SFA. Photon-counting CTAs were performed under contrast perfusion in SR and UHR mode with dose-equivalent 120kVp acquisition protocols (low-/ medium-/ high-dose: CTDIVol=3, 5, 10 mGy) and reconstructed with four vascular convolution kernels. Lumen visibility and contrast-to-noise ratio were compared using analyses of variance. Subjective image quality was assessed using a pairwise, forced-choice comparison software. RESULTS: Lumen visibility was equal for SR and UHR at the used dose levels. CNR increase by UHR was significant for (ultra-)sharp convolution kernels BV60 (3 mGy; UHR vs. SR, 19.9 ± 1.9 vs. 15.7 ± 1.6, p < 0.046) and BV76 (8.0 ± 0.6 vs. 5.4 ± 0.3, p < 0.001). The relative CNR increase was higher for low-dose than high-dose scans (BV76: 48% vs. 36% at high dose, p < 0.033). The CNR of the low-dose scan in UHR mode was comparable to the high-dose scan in SR mode when the ultra-sharp kernel was used (8.0 ± 0.6 vs. 9.1 ± 1.1, p > 0.760). Among UHR examinations, a significant increase in CNR could only be measured in BV76 (8.0 ± 0.6 (3 mGy) vs. 12.4 ± 0.9 (10 mGy), p < 0.001). Readers preferred subjective image quality of UHR for all kernels with BV76 being ranked highest. CONCLUSION: The CNR increase in UHR mode is highest when combining low radiation dose and ultra-sharp reconstructions. Meanwhile, the subjective image quality in UHR mode generally supersedes SR images, suggesting further dose reduction potential.

Photon-Counting Detector CT Angiography Versus Digital Subtraction Angiography in Patients with Peripheral Arterial Disease.

RATIONALE AND OBJECTIVES: This study aims to compare the diagnostic confidence of photon-counting detector CT angiography (PCD-CTA) depending on the used vascular reformatting kernels with digital subtraction angiography (DSA) as diagnostic reference standard in peripheral arterial occlusive disease (PAOD). MATERIAL AND METHODS: In 39 patients, 45 lower extremity PCD-CTA with subsequent DSA were analyzed. Advanced PAOD (Fontaine stage 4) was ascertained in 77.8% of patients. CTA post-processing comprised three vascular kernels (Bv36/48/56). Objective image quality assessment included vessel attenuation, image noise, contrast-to-noise (CNR) and signal-to-noise ratios (SNR). Subjective evaluation of calcium blooming, vessel sharpness, luminal attenuation and image noise was performed by three radiologists. Diagnostic performance and concordance to DSA were assessed. RESULTS: The luminal attenuation remained kernel-independent constant. With sharper kernels, image noise increased substantially, while SNR and CNR decreased. Subjective reduction of calcium blooming and increased vessel sharpness were noted for the sharp Bv56 kernel. While sensitivity in stenosis quantification was comparable between kernels (81.6% vs. 81.5% vs. 81.0%, p = 0.797), specificity increased slightly higher sharpness (71.1% vs. 76.9% vs. 79.6%, p = 0.067). Diagnostic concordance of stenosis ratings compared to DSA increased likewise (Bv36 vs. Bv56, p = 0.002). Severe crural vessel calcifications had no influence on sensitivity, regardless of kernel selection. Contrarily, specificity was substantially worse in severely calcified tibial vessels but could be improved by using the sharp Bv56 kernel (Bv36 vs. Bv56 p = 0.024). Diagnostic confidence was highest for Bv56. CONCLUSION: In lower leg PCD-CTA, sharp convolution kernels increase diagnostic confidence compared to DSA by improved vessel delineation and reduced calcium blooming with acceptable image noise.

Training for endovascular therapy of acute arterial disease and procedure-related complication: An extracorporeally-perfused human cadaver model study.

PURPOSE: The aim of this study was to evaluate the usability of a recently developed extracorporeally-perfused cadaver model for training the angiographic management of acute arterial diseases and periprocedural complications that may occur during endovascular therapy of the lower extremity arterial runoff. MATERIALS AND METHODS: Continuous extracorporeal perfusion was established in three fresh-frozen body donors via inguinal and infragenicular access. Using digital subtraction angiography for guidance, both arterial embolization (e.g., embolization using coils, vascular plugs, particles, and liquid embolic agents) and endovascular recanalization procedures (e.g., manual aspiration or balloon-assisted embolectomy) as well as various embolism protection devices were tested. Furthermore, the management of complications during percutaneous transluminal angioplasty, such as vessel dissection and rupture, were exercised by implantation of endovascular dissection repair system or covered stents. Interventions were performed by two board-certified interventional radiologists and one resident with only limited angiographic experience. RESULTS: Stable extracorporeal perfusion was successfully established on both thighs of all three body donors. Digital subtraction angiography could be performed reliably and resulted in realistic artery depiction. The model allowed for repeatable training of endovascular recanalization and arterial embolization procedures with typical tactile feedback in a controlled environment. Furthermore, the handling of more complex angiographic devices could be exercised. Whereas procedural success was be ascertained for most endovascular interventions, thrombectomies procedures were not feasible in some cases due to the lack of inherent coagulation. CONCLUSION: The presented perfusion model is suitable for practicing time-critical endovascular interventions in the lower extremity runoff under realistic but controlled conditions.

Photon-Counting Detector CT for Femoral Stent Imaging in an Extracorporeally Perfused Human Cadaveric Model.

BACKGROUND AND AIMS: This study aims to compare the performance of first-generation dual-source photon-counting detector computed tomography (PCD-CT) to third-generation dual-source energy-integrating detector (EID-CT) regarding stent imaging in the femoral arterial runoff. METHODS: Continuous extracorporeal perfusion was established in 1 human cadaver using an inguinal and infragenicular access and peristaltic pump. Seven peripheral stents were implanted into both superior femoral arteries by means of percutaneous angioplasty. Radiation dose-equivalent CT angiographies (high-/medium-/low-dose: 10/5/3 mGy) with constant tube voltage of 120 kVp, matching iterative reconstruction algorithm levels, and convolution kernels were used both with PCD-CT and EID-CT. In-stent lumen visibility, luminal and in-stent attenuation as well as contrast-to-noise ratio (CNR) were assessed via region of interest and diameter measurements. Results were compared using analyses of variance and regression analyses. RESULTS: Maximum in-stent lumen visibility achieved with PCD-CT was 94.48% ± 2.62%. The PCD-CT protocol with the lowest lumen visibility (BV40: 78.93% ± 4.67%) performed equal to the EID-CT protocol with the best lumen visibility (BV59: 79.49% ± 2.64%, P > 0.999). Photon-counting detector CT yielded superior CNR compared with EID-CT regardless of kernel and dose level ( P < 0.001). Maximum CNR was 48.8 ± 17.4 in PCD-CT versus 31.28 ± 5.7 in EID-CT (both BV40, high-dose). The theoretical dose reduction potential of PCD-CT over EID-CT was established at 88% (BV40), 83% (BV48/49), and 73% (BV59/60), respectively. In-stent attenuation was not significantly different from luminal attenuation outside stents in any protocol. CONCLUSIONS: With superior lumen visibility and CNR, PCD-CT allowed for noticeable dose reduction over EID-CT while maintaining image quality in a continuously perfused human cadaveric model.

An Intra-Individual Comparison of Low-keV Photon-Counting CT versus Energy-Integrating-Detector CT Angiography of the Aorta.

This retrospective study aims to provide an intra-individual comparison of aortic CT angiographies (CTAs) using first-generation photon-counting-detector CT (PCD-CT) and third-generation energy-integrating-detector CT (EID-CT). High-pitch CTAs were performed with both scanners and equal contrast-agent protocols. EID-CT employed automatic tube voltage selection (90/100 kVp) with reference tube current of 434/350 mAs, whereas multi-energy PCD-CT scans were generated with fixed tube voltage (120 kVp), image quality level of 64, and reconstructed as 55 keV monoenergetic images. For image quality assessment, contrast-to-noise ratios (CNRs) were calculated, and subjective evaluation (overall quality, luminal contrast, vessel sharpness, blooming, and beam hardening) was performed independently by three radiologists. Fifty-seven patients (12 women, 45 men) were included with a median interval between examinations of 12.7 months (interquartile range 11.1 months). Using manufacturer-recommended scan protocols resulted in a substantially lower radiation dose in PCD-CT (size-specific dose estimate: 4.88 ± 0.48 versus 6.28 ± 0.50 mGy, p < 0.001), while CNR was approximately 50% higher (41.11 ± 8.68 versus 27.05 ± 6.73, p < 0.001). Overall image quality and luminal contrast were deemed superior in PCD-CT (p < 0.001). Notably, EID-CT allowed for comparable vessel sharpness (p = 0.439) and less pronounced blooming and beam hardening (p < 0.001). Inter-rater agreement was good to excellent (0.58-0.87). Concluding, aortic PCD-CTAs facilitate increased image quality with significantly lower radiation dose compared to EID-CTAs.

Comparison of ultrahigh and standard resolution photon-counting CT angiography of the femoral arteries in a continuously perfused in vitro model.

BACKGROUND: With the emergence of photon-counting CT, ultrahigh-resolution (UHR) imaging can be performed without dose penalty. This study aims to directly compare the image quality of UHR and standard resolution (SR) scan mode in femoral artery angiographies. METHODS: After establishing continuous extracorporeal perfusion in four fresh-frozen cadaveric specimens, photon-counting CT angiographies were performed with a radiation dose of 5 mGy and tube voltage of 120 kV in both SR and UHR mode. Images were reconstructed with dedicated convolution kernels (soft: Body-vascular (Bv)48; sharp: Bv60; ultrasharp: Bv76). Six radiologists evaluated the image quality by means of a pairwise forced-choice comparison tool. Kendall's concordance coefficient (W) was calculated to quantify interrater agreement. Image quality was further assessed by measuring intraluminal attenuation and image noise as well as by calculating signal-to-noise ratio (SNR) and contrast-to-noise ratios (CNR). RESULTS: UHR yielded lower noise than SR for identical reconstructions with kernels ≥ Bv60 (p < 0.001). UHR scans exhibited lower intraluminal attenuation compared to SR (Bv60: 406.4 ± 25.1 versus 418.1 ± 30.1 HU; p < 0.001). Irrespective of scan mode, SNR and CNR decreased while noise increased with sharper kernels but UHR scans were objectively superior to SR nonetheless (Bv60: SNR 25.9 ± 6.4 versus 20.9 ± 5.3; CNR 22.7 ± 5.8 versus 18.4 ± 4.8; p < 0.001). Notably, UHR scans were preferred in subjective assessment when images were reconstructed with the ultrasharp Bv76 kernel, whereas SR was rated superior for Bv60. Interrater agreement was high (W = 0.935). CONCLUSIONS: Combinations of UHR scan mode and ultrasharp convolution kernel are able to exploit the full image quality potential in photon-counting CT angiography of the femoral arteries. RELEVANCE STATEMENT: The UHR scan mode offers improved image quality and may increase diagnostic accuracy in CT angiography of the peripheral arterial runoff when optimized reconstruction parameters are chosen. KEY POINTS: • UHR photon-counting CT improves image quality in combination with ultrasharp convolution kernels. • UHR datasets display lower image noise compared with identically reconstructed standard resolution scans. • Scans in UHR mode show decreased intraluminal attenuation compared with standard resolution imaging.

Pancreatic Ischemia-Reperfusion Injury Following Endovascular Treatment of Symptomatic Celiac and Superior Mesenteric Artery Stenosis.

CLINICAL IMPACT: With endovascular therapy becoming the first-line treatment for symptomatic chronic mesenteric ischemia, acute pancreatitis within the context of abdominal ischemia-reperfusion injury may be seen more often in cross-sectional imaging following this kind of interventions and should therefore be kept in mind by the reading physician.

Standardized assessment of vascular reconstruction kernels in photon-counting CT angiographies of the leg using a continuous extracorporeal perfusion model.

This study evaluated the influence of different vascular reconstruction kernels on the image quality of CT angiographies of the lower extremity runoff using a 1st-generation photon-counting-detector CT (PCD-CT) compared with dose-matched examinations on a 3rd-generation energy-integrating-detector CT (EID-CT). Inducing continuous extracorporeal perfusion in a human cadaveric model, we performed CT angiographies of eight upper leg arterial runoffs with radiation dose-equivalent 120 kVp acquisition protocols (CTDIvol 5 mGy). Reconstructions were executed with different vascular kernels, matching the individual modulation transfer functions between scanners. Signal-to-noise-ratios (SNR) and contrast-to-noise-ratios (CNR) were computed to assess objective image quality. Six radiologists evaluated image quality subjectively using a forced-choice pairwise comparison tool. Interrater agreement was determined by calculating Kendall's concordance coefficient (W). The intraluminal attenuation of PCD-CT images was significantly higher than of EID-CT (414.7 ± 27.3 HU vs. 329.3 ± 24.5 HU; p < 0.001). Using comparable kernels, image noise with PCD-CT was significantly lower than with EID-CT (p ≤ 0.044). Correspondingly, SNR and CNR were approximately twofold higher for PCD-CT (p < 0.001). Increasing the spatial frequency for PCD-CT reconstructions by one level resulted in similar metrics compared to EID-CT (CNRfat; EID-CT Bv49: 21.7 ± 3.7 versus PCD-CT Bv60: 21.4 ± 3.5). Overall image quality of PCD-CTA achieved ratings superior to EID-CTA irrespective of the used reconstruction kernels (best: PCD-CT Bv60; worst: EID-CT Bv40; p < 0.001). Interrater agreement was good (W = 0.78). Concluding, PCD-CT offers superior intraluminal attenuation, SNR, and CNR compared to EID-CT in angiographies of the upper leg arterial runoff. Combined with improved subjective image quality, PCD-CT facilitates the use of sharper convolution kernels and ultimately bears the potential of improved vascular structure assessability.

Continuous extracorporeal femoral perfusion model for intravascular ultrasound, computed tomography and digital subtraction angiography.

OBJECTIVES: We developed a novel human cadaveric perfusion model with continuous extracorporeal femoral perfusion suitable for performing intra-individual comparison studies, training of interventional procedures and preclinical testing of endovascular devices. Objective of this study was to introduce the techniques and evaluate the feasibility for realistic computed tomography angiography (CTA), digital subtraction angiography (DSA) including vascular interventions, and intravascular ultrasound (IVUS). METHODS: The establishment of the extracorporeal perfusion was attempted using one formalin-fixed and five fresh-frozen human cadavers. In all specimens, the common femoral and popliteal arteries were prepared, introducer sheaths inserted, and perfusion established by a peristaltic pump. Subsequently, we performed CTA and bilateral DSA in five cadavers and IVUS on both legs of four donors. Examination time without unintentional interruption was measured both with and without non-contrast planning CT. Percutaneous transluminal angioplasty and stenting was performed by two interventional radiologists on nine extremities (five donors) using a broad spectrum of different intravascular devices. RESULTS: The perfusion of the upper leg arteries was successfully established in all fresh-frozen but not in the formalin-fixed cadaver. The experimental setup generated a stable circulation in each procedure (ten upper legs) for a period of more than six hours. Images acquired with CT, DSA and IVUS offered a realistic impression and enabled the sufficient visualization of all examined vessel segments. Arterial cannulating, percutaneous transluminal angioplasty as well as stent deployment were feasible in a way that is comparable to a vascular intervention in vivo. The perfusion model allowed for introduction and testing of previously not used devices. CONCLUSIONS: The continuous femoral perfusion model can be established with moderate effort, works stable, and is utilizable for medical imaging of the peripheral arterial system using CTA, DSA and IVUS. Therefore, it appears suitable for research studies, developing skills in interventional procedures and testing of new or unfamiliar vascular devices.

Bilateral inferior petrosal sinus sampling: Procedural data from a German single-center study.

PURPOSE: To assess radiation exposure and diagnostic performance of bilateral inferior petrosal sinus sampling for the distinction of pituitary and ectopic adrenocorticotropin-dependent Cushing's syndrome. MATERIALS AND METHODS: Procedural data of bilateral inferior petrosal sinus procedures were retrospectively evaluated. The analysis included the patients' clinical and demographic data, procedural radiation exposure, and complication rates, sampling results, clinical course of the patients, and calculation of diagnostic performance data. RESULTS: The cases of 46 patients diagnosed with adrenocorticotropin-dependent Cushing's syndrome were evaluated. Bilateral inferior petrosal sinus sampling was successfully performed in 97.8 % of the cases. The overall median procedure-related fluoroscopy time was 7.8 min. (range 3.2-36.2 min.), and the median procedural dose area product was 11.9 Gy*cm2 (range 2.1-73.7 Gy*cm2). Radiation doses due to digital subtraction angiography series for visualization of the inferior petrosal sinus were 3.6 Gy*cm2 (range 1.0-18.1 Gy*cm2). Radiation doses due to fluoroscopy had a higher impact on the overall radiation exposure and were significantly influenced by the patients' habitus. The sensitivity, specificity, and positive and negative predictive values were 84 %, 100 %, 100 %, and 72 % before stimulation with corticotropin-releasing hormone, and 97 %, 100 %, 100 %, and 93 % after stimulation. Concordance between magnetic resonance imaging studies and bilateral inferior petrosal sinus sampling results was only found in 35.6 % of the cases. The periprocedural complication rate was 2.2 %, with one patient experiencing vasovagal syncope during catheterization. CONCLUSION: Bilateral inferior petrosal sinus sampling is a safe procedure with high technical success rates und excellent diagnostic performance. The procedure-related radiation exposure shows large variations and depends on the complexity of cannulation as well as the patients' habitus. Fluoroscopy accounted for the largest proportion of radiation exposure. Acquisition of digital subtraction angiography series for the verification of correct catheter placement appears justified. KEY POINTS: · Bilateral inferior petrosal sinus sampling with CRH stimulation provides high diagnostic performance in the distinction of pituitary and ectopic Cushing's syndrome.. · The associated radiation exposure is not negligible and is significantly influenced by the use of fluoroscopy and the patients' habitus.. · Digital subtraction angiography contributes less to the overall radiation dose and appears justified for the verification of correct catheter placement.. CITATION FORMAT: · Augustin A, Detomas M, Hartung V et al. Bilateral inferior petrosal sinus sampling: Procedural data from a German single-center study. Fortschr Röntgenstr 2023; 195: 1009 - 1017.

Malignant obstruction of the inferior vena cava: clinical experience with the self-expanding Sinus-XL stent system.

PURPOSE: To evaluate the technical and clinical outcome of Sinus-XL stent placement in patients with malignant obstruction syndrome of the inferior vena cava. METHODS: Between October 2010 and January 2021, 21 patients with different malignant primary disease causing inferior vena cava obstruction were treated with Sinus-XL stent implantation. Procedural data, technical and clinical outcome parameters were retrospectively analyzed. RESULTS: Technical success was 100%. Analysis of available manometry data revealed a significant reduction of the mean translesional pressure gradient following the procedure (p = 0.008). Reintervention rate was 4.8% (1/21). The available follow-up imaging studies showed primary and primary-assisted stent patency rates of 93% (13/14) and 100% (14/14), respectively. Major complications did not occur. The clinical success regarding lower extremity edema was 82.4% (14/17) for the first and 85.7% (18/21) for the last follow-up. Longer lengths of IVC obstruction were associated with reduced clinical improvement after the procedure (p = 0.025). Improvement of intraprocedural manometry results and lower extremity edema revealed only minor correlation. Ascites and anasarca were not significantly positively affected by the procedure. CONCLUSION: Sinus-XL stent placement in patients with malignant inferior vena cava obstruction showed high technical success and low complication rates. Regarding the clinical outcome, significant symptom improvement could be achieved in lower extremity edema, whereas ascites and anasarca lacked satisfying symptom relief. Based on our results, this procedure should be considered as a suitable therapy in a palliative care setting for patients with advanced malignant disease.

2D-perfusion angiography for intra-procedural endovascular treatment response assessment in chronic mesenteric ischemia: a feasibility study.

BACKGROUND: Endovascular revascularization has become the first-line treatment of chronic mesenteric ischemia (CMI). The qualitative visual analysis of digital subtraction angiography (DSA) is dependent on observer experience and prone to interpretation errors. We evaluate the feasibility of 2D-Perfusion Angiography (2D-PA) for objective, quantitative treatment response assessment in CMI. METHODS: 49 revascularizations in 39 patients with imaging based evidence of mesenteric vascular occlusive disease and clinical signs of CMI were included in this retrospective study. To assess perfusion changes by 2D-PA, DSA-series were post-processed using a dedicated, commercially available software. Regions of interest (ROI) were placed in the pre- and post-stenotic artery segment. In aorto-ostial disease, the inflow ROI was positioned at the mesenteric artery orifice. The ratios outflow to inflow ROI for peak density (PD), time to peak and area-under-the-curve (AUC) were computed and compared pre- and post-interventionally. We graded motion artifacts by means of a four-point scale. Feasibility of 2D-PA and changes of flow parameters were evaluated. RESULTS: Motion artifacts due to a mobile vessel location beneath the diaphragm or within the mesenteric root, branch vessel superimposition and inadequate contrast enhancement at the inflow ROI during manually conducted DSA-series via selective catheters owing to steep vessel angulation, necessitated exclusion of 26 measurements from quantitative flow evaluation. The feasibility rate was 47%. In 23 technically feasible assessments, PDoutflow/PDinflow increased by 65% (p < 0.001) and AUCoutflow/AUCinflow increased by 85% (p < 0.001). The time to peak density values in the outflow ROI accelerated only minimally without reaching statistical significance. Age, BMI, target vessel (celiac trunk, SMA or IMA), stenosis location (ostial or truncal), calcification severity, plaque composition or the presence of a complex stenosis did not reach statistical significance in their distribution among the feasible and non-feasible group (p > 0.05). CONCLUSIONS: Compared to other vascular territories and indications, the feasibility of 2D-PA in mesenteric revascularization for CMI was limited. Unfavorable anatomic conditions contributed to a high rate of inconclusive 2D-PA results.

Percutaneous implantation of peripherally inserted totally implantable venous access systems in the forearm in adolescent patients.

BACKGROUND: Children with different underlying malignant diseases require long-term central venous access. As for port systems in a pectoral position, peripherally implanted port systems in the forearm revealed high levels of technical and clinical success in adult cohorts. OBJECTIVE: To investigate the technical and clinical outcomes of percutaneous central venous port implantation in the forearm in adolescents. MATERIALS AND METHODS: Between April 2010 and August 2020, 32 children ages 9 to 17 years with underlying malignancy received 35 totally implantable venous access ports (TIVAPs) in the forearm. All venous port systems were peripherally inserted under ultrasound guidance. Correct catheter placement was controlled by fluoroscopy. As primary endpoints, the technical success, rate of complications and catheter maintenance were analyzed. Secondary endpoints were the side of implantation, vein of catheter access, laboratory results on the day of the procedure, procedural radiation exposure, amount of contrast agent and reasons for port device removal. RESULTS: Percutaneous TIVAP placement under sonographic guidance was technically successful in 34 of 35 procedures (97.1%). Procedure-related complications did not occur. During the follow-up, 13,684 catheter days were analyzed, revealing 11 complications (0.8 per 1,000 catheter-duration days), Of these 11 complications, 7 were major and 10 occurred late. In seven cases, the port device had to be removed; removal-related complications did not occur. CONCLUSION: Peripheral TIVAP placement in the forearms of children is a feasible, effective and safe technique with good midterm outcome. As results are comparable with standard access routes, this technique may be offered as an alternative when intermittent venous access is required.

Color-coded summation images for the evaluation of blood flow in endovascular aortic dissection fenestration.

BACKGROUND: To analyze the benefit of color-coded summation images in the assessment of target lumen perfusion in patients with aortic dissection and malperfusion syndrome before and after fluoroscopy-guided aortic fenestration. METHODS: Between December 2011 and April 2020 25 patients with Stanford type A (n = 13) or type B dissection (n = 12) and malperfusion syndromes were treated with fluoroscopy-guided fenestration of the dissection flap using a re-entry catheter. The procedure was technically successful in 100% of the cases and included additional iliofemoral stent implantation in four patients. Intraprocedural systolic blood pressure measurements for gradient evaluation were performed in 19 cases. Post-processed color-coded DSA images were obtained from all DSA series before and following fenestration. Differences in time to peak (dTTP) values in the compromised aortic lumen and transluminal systolic blood pressure gradients were analyzed retrospectively. Correlation analysis between dTTP and changes in blood pressure gradients was performed. RESULTS: Mean TTP prior to dissection flap fenestration was 6.85 ± 1.35 s. After fenestration, mean TTP decreased significantly to 4.96 ± 0.94 s (p < 0.001). Available systolic blood pressure gradients between the true and the false lumen were reduced by a median of 4.0 mmHg following fenestration (p = 0.031), with significant reductions in Stanford type B dissections (p = 0.013) and minor reductions in type A dissections (p = 0.530). A moderate correlation with no statistical significance was found between dTTP and the difference in systolic blood pressure (r = 0.226; p = 0.351). CONCLUSIONS: Hemodynamic parameters obtained from color-coded DSA confirmed a significant reduction of TTP values in the aortic target lumen in terms of an improved perfusion in the compromised aortic region. Color-coded DSA might thus be a suitable complementary tool in the assessment of complex vascular patterns prevailing in aortic dissections, especially when blood pressure measurements are not conclusive or feasible.

Percutaneous mechanical thrombectomy device assisted TIPS recanalization: a feasibility study.

BACKGROUND: Despite improved shunt patency, transjugular intrahepatic portosystemic shunt (TIPS) occlusion remains a serious complication, and effective debulking of the existing tract is needed to restore sufficient blood flow. PURPOSE: To evaluate the technical and clinical success of percutaneous mechanical thrombectomy in restoring patency of acutely and chronically thrombosed covered TIPS using the Aspirex®S and Rotarex®S system. MATERIAL AND METHODS: We evaluated mechanical thrombectomy-assisted revisions in five patients between January 2012 and April 2021. Two patients had to be revised twice due to recurrent occlusion. We designated thrombosis within 10 days after shunt creation or revision as acute. Insidious deterioration of portal hypertension related symptoms for at least 6-8 weeks was recorded in chronic cases. We treated four acute and three chronic occlusions. After transjugular lesion crossing, we performed two mechanical thrombectomy device passages. If indicated, balloon dilatation, covered stent placement, or variceal embolization were added. RESULTS: The technical success rate was 100%. No procedure-related complications occurred. In one patient with acute decompensation of Budd-Chiari syndrome and acute-on-chronic liver failure, early re-thrombosis occurred twice with patency intervals of up to eight days. In contrast, stable patency was achieved in the other four patients with documented patency intervals of at least five months and improvement of portal hypertension-related symptoms, resulting in a patient based clinical success rate of 80%. CONCLUSION: In five patients, percutaneous mechanical thrombectomy assisted TIPS recanalization of four acute and three chronic occlusions proved to be technically feasible and safe with a high clinical success rate.