Performance Evaluation of a Miniature and Disposable Endovascular Robotic Device.

PURPOSE: The LIBERTY® Robotic System is a miniature, single-use device designed to facilitate remote-controlled navigation to intravascular targets. We aim to evaluate the robot's performance to manipulate a range of microguidewires and microcatheters during percutaneous endovascular procedures. MATERIALS AND METHODS: Six interventional radiologists performed selective robotic-assisted catheterization of eight pre-determined vascular targets in a pig model. The navigation time from the guiding catheter tip to the target vessel was recorded. Each physician with a clinical experience of 20 years completed a questionnaire to evaluate the ease of use, accuracy, and safety of the robotic operation. RESULTS: Most of the physicians reached the vascular targets in less than one minute. There was no angiographic evidence of vascular injury such as artery laceration or contusion. All physicians reported consensus about the high performance of the robot. CONCLUSION: The miniature disposable robot is effective at reaching a range of vessels in a porcine model. Physicians found the device intuitive and easy to operate remotely.

Contrast-Enhanced Ultrasound after Endovascular Aortic Repair: Supplement and Potential Substitute for CT in Early- and Long-Term Follow-Up.

BACKGROUND: Endoleaks are the most common complication after endovascular aneurysm repair (EVAR). Computed tomography angiography (CTA) is presently the golden standard for lifelong surveillance after EVAR. Several studies and meta-analyses have shown contrast-enhanced ultrasound (CEUS) to be a good alternative. The main goal of our study was to further validate the inclusion of CEUS in follow-up examination protocols for the systematic surveillance after EVAR. METHODS: A retrospective analysis of patients who had received CEUS as part of their routine surveillance after EVAR at our center was conducted. Detection rate and classification of endoleak types were compared between available postinterventional CTA/magnetic resonance angiography and follow-up CEUS examinations. Last preinterventional CTAs before EVAR served as baselines with focus on potential cofactors such as age, body mass index, maximum aortic aneurysm diameters, endoleak orientation, and distance-to-surface influencing detection rates and classification. RESULTS: In total, 101 patients were included in the analysis. Forty-four endoleaks (43.5% of cases) were detected by either initial CEUS or CTA, mostly type II (37.6% of the included patients). Initial CEUS showed an endoleak sensitivity of 91.2%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 84.6%. No covariate with an influence on the correct classification could be identified either for CEUS or CT. CONCLUSIONS: CEUS should be considered a valid complementary method to CTA in the lifelong surveillance after EVAR. As type II endoleaks seem to be a common early-term, sometimes spontaneously resolving complication that can potentially be missed by CTA, we suggest combined follow-up protocols including CEUS in the early on postinterventional assessment.

Image fusion guidance for left subclavian artery in situ fenestration during thoracic endovascular repair.

OBJECTIVES: To evaluate the feasibility and clinical benefit of utilizing image fusion for thoracic endovascular repair (TEVAR) with in situ fenestration (ISF-TEVAR). MATERIALS AND METHODS: Between January 2020 and December 2020, we prospectively collected 18 consecutive cases with complex thoracic aortic lesions who underwent image fusion guided ISF-TEVAR. As a control group, 18 patients were collected from historical medical records from June 2019 to December 2019. The fusion group involved the use of 3D fusion of CTA and fluoroscopic images for real-time 3D guidance, and the control group involved the use of only regular fluoroscopic images for guidance. The total contrast medium volume, hand-injected contrast medium volume, overall operative time, radiation dose and fluoroscopy time were compared between the two groups. Accuracy was measured based on preoperative CTA and intraoperative digital subtraction angiography. RESULTS: 3D fusion imaging guidance was successfully implemented in all patients in the fusion group. Hand-injected contrast medium volume and overall operative time were significantly lower in the fusion group than in the control group (p = .028 and p = .011). Compared with the control group, the fusion group showed a significant reduction in time and radiation dose-area product (DAP) for fluoroscopy (p = .004 and p = .010). No significant differences in total radiation dose (DAP) or total contrast medium volume were observed (p = .079 and p = .443). Full accuracy was achieved in 8 cases (44%), with a mean deviation of 2.61 mm ± 3.1 (range 0.0-8.4 mm). CONCLUSIONS: 3D image fusion for ISF-TEVAR was associated with a significant reduction in hand-injected contrast medium, time and radiation exposure for fluoroscopy and overall operative time. The image fusion guidance showed potential clinical benefits towards improved treatment safety and accuracy for complex thoracic endovascular interventions.

Local Anesthesia for Endovascular Repair of Abdominal Aortic Aneurysm Allows for Accurate Graft Deployment with Durable Results.

BACKGROUND: Local anesthesia (LA) is sparsely used in endovascular aneurysm repair (EVAR) despite short-term benefit, likely secondary to concerns over patient movement preventing accurate endograft deployment. The objective of this study is to examine the association between anesthesia type and endoleak, sac regression, reintervention, and mortality. METHODS: The Vascular Quality Initiative database was queried for all EVAR cases from 2014 to 2022. Patients were included if they underwent percutaneous elective EVAR with anatomical criteria within instructions for use of commercially approved endografts. Multivariable logistic regression with propensity score weighting was used to determine the association between anesthesia type on the risk of any endoleak noted by intraoperative completion angiogram and sac regression. Multivariable survival analysis with propensity score weighting was used to determine the association between anesthesia type and endoleak at 1 year, long-term reintervention, and mortality. RESULTS: Thirteen thousand nine hundred thirty two EVARs met inclusion criteria: 1,075 (8%) LA and 12,857 (92%) general anesthesia (GA). On completion angiogram, LA was associated with fewer rates of any endoleaks overall (16% vs. 24%, P < 0.001). On multivariable analysis with propensity score weighting, LA was associated with similar adjusted odds of any endoleak on intraoperative completion angiogram (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.47-0.68) as well as combined type 1a and type 1b endoleaks (OR 0.72, 95% CI 0.47-1.09). Follow-up computed tomography imaging at 1 year was available for 4,892 patients, 377 (8%) LA and 4,515 (92%) GA. At 1 year, LA was associated with similar rate of freedom from any endoleaks compared to GA (0.66 [95% CI 0.63-0.69] vs. 0.71 [95% CI 0.70-0.72], P = 0.663) and increased rates of sac regression (50% vs. 45%, P = 0.040). On multivariable analysis with propensity score weighting, LA and GA were associated with similar adjusted odds of sac regression (OR 1.22, 95% CI 0.97-1.55). LA and GA had similar rates of endoleak at 1 year (hazard ratio [HR] 0.14, 95% CI 0.63-1.07); however, LA was associated with decreased hazards of combined type 1a and 1b endoleaks at 1 year (HR 0.87, 95% CI 0.80-0.96). LA and GA had similar adjusted long-term reintervention rate (HR 0.77, 95% CI 0.44-1.38) and long-term mortality (HR 1.100, 95% CI 079-1.25). CONCLUSIONS: LA is not associated with increased adjusted rates of any endoleak on completion angiogram or at 1-year follow-up compared to GA. LA is associated with decreased adjusted rates of type 1a and type 1b endoleak at 1 year, but similar rates of sac regression, long-term reintervention, and mortality. Concerns for accurate graft deployment should not preclude use of LA and LA should be increasingly considered when deciding on anesthetic type for standard elective EVAR.

Clinical comparative analysis of 3D printing-assisted extracorporeal pre-fenestration and Castor integrated branch stent techniques in treating type B aortic dissections with inadequate proximal landing zones.

BACKGROUND: This study aims to compare the clinical effects of two distinct surgical approaches, namely 3D printing-assisted extracorporeal pre-fenestration and Castor integrated branch stent techniques, in treating patients with Stanford type B aortic dissections (TBAD) characterized by inadequate proximal landing zones. METHODS: A retrospective analysis was conducted on 84 patients with type B aortic dissection (TBAD) who underwent thoracic endovascular aortic repair (TEVAR) with left subclavian artery (LSA) reconstruction at our center from January 2022 to July 2023. Based on the different surgical approaches, the patients were divided into two groups: the group assisted by 3D printing for extracorporeal pre-fenestration (n = 44) and the group using the castor integrated branch stent (n = 40). Clinical indicators: including general patient information, operative time, surgical success rate, intraoperative and postoperative complication rates, re-intervention rate, and mortality, as well as postoperative aortic remodeling, were compared between the two groups. The endpoint of this study is the post-TEVAR mortality rate in patients. RESULTS: The surgical success rate and device deployment success rate were 100% in both groups, with no statistically significant difference (P > 0.05). However, the group assisted by 3D printing for extracorporeal pre-fenestration had a significantly longer operative time (184.20 ± 54.857 min) compared to the group using the castor integrated branch stent (152.75 ± 33.068 min), with a statistically significant difference (t = 3.215, p = 0.002, P < 0.05). Moreover, the incidence of postoperative cerebral infarction and beak sign was significantly lower in the group assisted by 3D printing for extracorporeal pre-fenestration compared to the castor-integrated branch stent group, demonstrating statistical significance. There were no significant differences between the two groups in terms of other postoperative complication rates and aortic remodeling (P > 0.05). Notably, computed tomography angiography images revealed the expansion of the vascular true lumen and the reduction of the false lumen at three specified levels of the thoracic aorta. The follow-up duration did not show any statistically significant difference between the two groups (10.59 ± 4.52 vs. 9.08 ± 4.35 months, t = 1.561, p = 0.122 > 0.05). Throughout the follow-up period, neither group experienced new endoleaks, spinal cord injuries, nor limb ischemia. In the castor-integrated branch stent group, one patient developed a new distal dissection, prompting further follow-up. Additionally, there was one case of mortality due to COVID-19 in each group. There were no statistically significant differences between the two groups in terms of re-intervention rate and survival rate (P > 0.05). CONCLUSION: Both 3D printing-assisted extracorporeal pre-fenestration TEVAR and castor-integrated branch stent techniques demonstrate good safety and efficacy in treating Stanford type B aortic dissection with inadequate proximal anchoring. The 3D printing-assisted extracorporeal pre-fenestration TEVAR technique has a lower incidence of postoperative cerebral infarction and beak sign, while the castor-integrated branch stent technique has advantages in operative time.

Very long-term follow-up after aortic stenting for coarctation of the aorta.

INTRODUCTION AND OBJECTIVES: Stent implantation is the preferred treatment in older children and adults with aortic coarctation (CoA). We aimed to determine the incidence of very late events after CoA stenting. METHODS: We analyzed a cohort of CoA patients who underwent stent implantation at our center between 1993 and 2018. Patients were periodically followed up in outpatient clinics, including computed tomography (CT) and fluoroscopy assessment. RESULTS: A total of 167 patients with CT and fluoroscopy data were included: 83 (49.7%) were aged ≤ 12 years and 46 (28%) were female. The mean clinical follow-up time was 17±8 (range 4-30) years and the mean time to CT/fluoroscopy was 11±7 years. Aortic aneurysm was present in 13% and was associated with the PALMAZ stent (OR, 3.09; 95%CI, 1.11-9.49; P=.036) and the stented length (OR, 0.94; 95%CI, 0.89-0.99; P=.039). Stent fracture was frequent (34%), but was not related to the presence of aneurysm. Stent fracture was associated with young age (OR, 3.57; 95%CI, 1.54-8.33; P=.003), male sex (OR, 4.00; 95%CI, 1.51-12.5, P=.008) and inversely with the PALMAZ stent (OR, 0.29; 95%CI, 0.12-0.67, P=.005). Reintervention was lower in adults (10%), mainly related to aneurysms. Those treated when aged ≤ 12 years had higher reintervention rates (43%) due to recoarctation somatic growth. CONCLUSIONS: This long-term follow-up study of CoA patients treated with stenting revealed a significant incidence of late events. Reintervention rates were higher in patients treated at younger ages. Periodic imaging surveillance appears to be advisable.

The effect of Fiber Optic RealShape technology on the reduction of radiation during complex endovascular surgery.

OBJECTIVE: Despite the advantages that fenestrated endovascular aortic repair has over open repair, it is accompanied by the consequence of radiation exposure, which can result in long-term complications for both the patient and surgical staff. Fiber Optic RealShape (FORS) technology is a novel advancement that uses emitted light from a fiber optic wire and enables the surgeon to cannulate vessels in real time without live fluoroscopy. This technology has been implemented at select centers to study its effectiveness for cannulation of target vessels and its impact on procedural radiation. METHODS: We collected prospective data on physician-modified endograft (PMEG) cases before and after the introduction of FORS technology. FORS PMEGs were matched with up to three conventional fluoroscopy cases by number of target vessels, inclusion of a bifurcated device below, aneurysm extent, and patient body mass index. The procedural radiation parameters were compared between these cohorts. Within the FORS cohort, we analyzed the rate of successful target vessel cannulation for all cases done with this technology (including cases other than PMEGs), and we compared the radiation between the cannulations using only FORS with those that abandoned FORS for conventional fluoroscopy. RESULTS: Nineteen FORS PMEGs were able to be matched to 45 conventional fluoroscopy cases. Procedures that used FORS technology had significantly reduced total air kerma (527 mGy vs 964 mGy), dose area product (121 Gy∗cm2 vs 186 Gy∗cm2), fluoroscopy dose (72.1 Gy∗cm2 vs 132.5 Gy∗cm2), and fluoroscopy time (45 minutes vs 72 minutes). There was no difference in procedure length, total contrast, or digital subtraction angiography. Within FORS cases, 66% of cannulations were completed using only FORS. Cannulations using only FORS had significant reduction of navigation air kerma (5.0 mGy vs 26.5 mGy), dose area product (1.2 Gy∗cm2 vs 5.1 Gy∗cm2), and fluoroscopy time (0.6 minutes vs 2.3 minutes) compared with cannulations abandoning FORS for conventional fluoroscopy. CONCLUSIONS: This study demonstrates the advantages of FORS for total procedural radiation as well as during individual cannulation tasks. The implementation of FORS for target vessel catheterization has the potential to decrease the total degree of radiation exposure for the patient and surgical staff during complex endovascular aortic surgeries.

Ultrasound Surveillance is Feasible After Endovascular Aneurysm Repair.

BACKGROUND: Surveillance after endovascular aneurysm repair (EVAR) is traditionally done with computed tomography angiography (CTA) scans that exposes patient to radiation, nephrotoxic contrast media, and potentially increased risk for cancer. Ultrasound (US) is less labor intensive and expensive and might thus provide a good alternative for CTA surveillance. The aim of this study was to evaluate in real-life patient cohorts whether US is able to detect post-EVAR aneurysm-related complications similarly to CTA. METHODS: This retrospective study compared the outcome of consecutive patients who underwent EVAR for intact abdominal aortic aneurysm and were surveilled solely by CTA (CTA-only cohort, n = 168) in 2000-2010 or by combined CTA and US (CTA/US cohort, n = 300) in 2011-2016, as a standard surveillance protocol in the department of vascular surgery, Helsinki University Hospital. The CTA-only patients were imaged at 1, 3, and 12 months and annually thereafter. The CTA/US patients were imaged with CTA at 3 and 12 months, US at 6 months and annually thereafter. If there were suspicion of >5 mm aneurysm growth, CTA scan was performed. The patients were reviewed for imaging data, reinterventions, aneurysm ruptures, and death until December 2018. The 2 groups were compared for secondary rupture, aneurysm-related and cancer-related death, reintervention related to abdominal aortic aneurysm, and maximum aneurysm diameter increase ≥5 mm. The mean follow-up in the CTA-only cohort was 67 months and in CTA/US cohort 43 months. RESULTS: The 2 cohorts were alike for basic characteristics and for the mean aneurysm diameter. The total number of CT scans for detecting aneurysm was 84.1/100 patient years in the CTA-only cohort compared to 74.5/100 patient years for US/CTA cohort. Forty percent of patients under combined CTA/US surveillance received 1 or more additional CTA scans. The 2 cohorts did not differ for 1-year, 5-year and 8-year freedom from aneurysm related death, secondary sac rupture, nor the incidence of rupture preventing interventions. CONCLUSIONS: Based on the follow-up data of this real-life cohort of 468 patients, combined surveillance with US and additional CTA either per protocol or due to suspicion of aneurysm-related complications had comparable outcome with sole CTA-surveillance. Thus, US can be considered a reasonable alternative for the CTA. However, our study showed also that the need of additional CTAs due to suspicion of endoleak or aneurysm nonrelated reasons is substantial.

Safety, Effectiveness and Pitfalls of Carbon Dioxide Routine Use as a Contrast Agent for Endovascular Abdominal Aortic Repair.

BACKGROUND: Despite the evidence of good performance, carbon dioxide (CO2) routine employment as a contrast agent for endovascular procedures is far from being adopted with its use currently limited to patients with renal impairment and known allergy to iodinated contrast medium (ICM). The purpose of our study is to evaluate the safety and effectiveness of CO2 guided endovascular abdominal aortic aneurysm repair (EVAR) in a standard population and to assess the rationale for a future widespread use. METHODS: We retrospectively collected data of every patient who underwent CO2 guided standard EVAR from September 2020 to May 2021 and compared them with the data of every patient who underwent EVAR using ICM from December 2019 to August 2020 in our unit. The selection of the contrast medium was not based on any preoperative factor as the contrast medium was routinely used in every patient in both periods. The primary end point of the study was the technical success rate. Secondary end points were the early and late complication rates, radiation exposure and renal function impairment. RESULTS: 49 patients underwent ICM guided EVAR and 52 patients underwent CO2 guided EVAR in our unit in the time frames specified above. The technical success rate was 100% in both groups with no accidental coverage of any target vessel. Intraoperative endoleaks were observed in 14% of ICM patients and 25% of CO2 patients. The radiation exposure was higher in the CO2 group if compared to the ICM group (311.48 vs. 159.86 median mGy/cm2 - P < 0.001). The incidence of postoperative acute kidney injury was low and similar in the 2 groups. No significant worsening over time of the renal function has been reported in both groups. CONCLUSIONS: EVAR can be safely performed under CO2 guidance without the integration of any quantity of ICM but with an increase in radiation exposure. The nephroprotective role of CO2 guided EVAR in a standard population is unclear and the same role in renal impaired patients should be validated with further studies on selected populations.

Predictive Parameters of Type 1A Endoleak for Elective Endovascular Aortic Repair: A Single-Center Experience.

BACKGROUND: One of the most important factors that affects the success of Endovascular Aortic Repair (EVAR) treatment is the morphology of the neck of the aneurysm. Today, EVAR can be performed even in patients who do not meet the Instruction For Use criteria with hostile neck risk factors; thanks to the developing experience and technology. Our aim in this study was to determine risk factors for Type 1a endoleaks in patients who underwent EVAR and predictive factors for Type 1a endoleaks in patients with combinations of these risk factors. METHODS: Patients who underwent elective EVAR for infrarenal abdominal aortic aneurysm in our medical center between July 2016 and January 2021 were enrolled. Of these 244 patients, 180 patients with documented preoperative and postoperative computed tomographic angiography results and a follow-up of at least 1 year were included in the study. The Mann-Whitney U test and Student's t-test were used to assess the relationship between nominal data and numerical values, and the t-test and Wilcoxon test were used to compare dependent groups. Logistic regression analysis was performed to model risk factors associated with endoleaks. RESULTS: The results showed that a neck length less than 15 mm increased the development of type 1a endoleak by 10.4 times (P < 0.001). Furthermore, a neck diameter more than 28 mm increased the development of type 1a endoleak by 21.9 times (P = 0.04). A conical neck structure (gradual neck dilation > 2 mm) increased the development of type 1a endoleaks 4.8 times (P = 0.04). The presence of calcification (> 150 Hounsfield Unit and > 2 mm) in the neck increased the risk of type 1a endoleaks fourfold (P = 0.04). Hostile neck parameters were analyzed and patients with only 1 parameter (n = 69) had a 7.2% type 1a endoleak rate, while patients with 2 parameters (n = 15) had 26.6% and patients with more than 2 parameters (n = 11) had 45.5% type 1a endoleak rate. CONCLUSIONS: Morphologic features of the neck structure of the aneurysm are among the most important parameters that affect the success of EVAR treatment. Alternative treatments should be considered in patients with more than 1 unfavorable neck parameter.

Computational prediction of proximal sealing in endovascular abdominal aortic aneurysm repair with unfavorable necks.

BACKGROUND AND OBJECTIVE: Endovascular aortic aneurysm repair (EVAR) has become the standard treatment for abdominal aortic aneurysms in most centers. However, proximal sealing complications leading to endoleaks and migrations sometimes occur, particularly in unfavorable aortic anatomies and are strongly dependent on biomechanical interactions between the aortic wall and the endograft. The objective of the present work is to develop and validate a computational patient-specific model that can accurately predict these complications. METHODS: Based on pre-operative CT-scans, we developed finite element models of the aorta of 10 patients who underwent endovascular aortic aneurysm repair, 7 with standard morphologies and 3 with unfavorable anatomies. We simulated the deployment of stent grafts in each aorta by solving mechanical equilibrium with a virtual shell method. Eventually we compared the actual stent ring positions from post-operative computed-tomography-scans with the predicted simulated positions. RESULTS: A successful deployment simulation could be performed for each patient. Relative radial, transverse and longitudinal deviations were 6.3 ± 4.4%, 2.5 ± 0.9 mm and 1.4 ± 1.1 mm, respectively. CONCLUSIONS: The numerical model predicted accurately stent-graft positions in the aortic neck of 10 patients, even in complex anatomies. This shows the potential of computer simulation to anticipate possible proximal endoleak complications before EVAR interventions.

Towards biomechanics-based pre-procedural planning for thoracic endovascular aortic repair of aortic dissection.

BACKGROUND AND OBJECTIVE: Although thoracic aortic endovascular repair (TEVAR) has shown promising outcomes in the treatment of patients with complicated type B aortic dissection, complications still occur after TEVAR that can lead to catastrophic events. Biomechanical interactions between the stent-graft (SG) and the local aortic tissue play a critical role in determining the outcome of TEVAR. Different SG design may cause different biomechanical responses in the treated aorta, but such information is not known at the time of pre-procedural planning. By developing patient-specific virtual stent-graft deployment tools, it is possible to analyse and compare the biomechanical impact of different SGs on the local aorta for individual patients. METHODS: A finite element based virtual SG deployment model was employed in this study. Computational simulations were performed on a patient-specific model of type B aortic dissection, accounting for details of the SG design and the hyperelastic behaviour of the aortic wall. Based on the geometry reconstructed from the pre-TEVAR CTA scan, the patient-specific aortic dissection model was created and pre-stressed. Parametric models of three different SG products (SG1, SG2 and SG3) were built with two different lengths for each design. The SG models incorporated different stent and graft materials, stent strut patterns, and assembly approaches. Using our validated SG deployment simulation framework, virtual trials were performed on the patient-specific aortic dissection model using different SG products and varying SG lengths. CONCLUSION: Simulation results for different SG products suggest that SG3 with a longer length (SG3-long) would be the most appropriate device for the individual patient. Compared to SG1-short (the SG deployed in the patient), SG3-long followed the true lumen tortuosity closely, resulted in a more uniform true lumen expansion and a significant reduction in peak stress in the distal landing zone. These simulation results are promising and demonstrate the feasibility of using the virtual SG deployment model to assist clinicians in pre-procedural planning.

Endograft position and endoleak detection after endovascular abdominal aortic repair with low-field tiltable MRI: a feasibility study.

BACKGROUND: Abdominal aortic endoleaks after endovascular aneurysm repair might be position-dependent, therefore undetectable using supine imaging. We aimed to determine the feasibility and benefit of using a low-field tiltable magnetic resonance imaging (MRI) scanner allowing to study patients who can be imaged in both supine and upright positions of endoleaks. METHODS: Ten EVAR patients suspected of endoleak based on ultrasound examination were prospectively included. MRI in upright and supine positions was compared with routine supine computed tomography angiography (CTA). Analysis was performed through (1) subjective image quality assessment by three observers, (2) landmark registration between MRI and CTA scans, (3) Euclidean distances between renal and endograft landmarks, and (4) evaluation of endoleak detection on MRI by a consensus panel. Statistical analysis was performed by one-way repeated measures analysis of variance. RESULTS: The image quality of upright/supine MRI was inferior compared to CTA. Median differences in both renal and endograft landmarks were approximately 6-7 mm between upright and supine MRI and 5-6 mm between supine MRI and CTA. In the proximal sealing zone of the endograft, no differences were found among all three scan types (p = 0.264). Endoleak detection showed agreement between MRI and CTA in 50% of the cases, with potential added value in only one patient. CONCLUSIONS: The benefit of low-field upright MRI for endoleak detection was limited. While MRI assessment was non-inferior to standard CTA in detecting endoleaks in selected cases, improved hardware and sequences are needed to explore the potential of upright MRI in patients with endoleaks. RELEVANCE STATEMENT: Upright low-field MRI has limited clinical value in detecting position-dependent endoleaks; improvements are required to fulfil its potential as a complementary modality in this clinical setting. KEY POINTS: • Upright MRI shows potential for imaging endoleaks in aortic aneurysm patients in different positions. • The image quality of upright MRI is inferior to current techniques. • Upright MRI complements CTA, but lacks accurate deformation measurements for clinical use. • Advancements in hardware and imaging sequences are needed to fully utilise upright MRI capabilities.

Bursting Heart Syndrome: A Rare Case Of Aortocaval Fistula Repair.

In this case report we will discuss the case of a 47-year-old woman who presented with abdominal pain, nausea, oliguria and right heart failure. A Computed Tomography (CT) aortogram revealed a fistulous abdominal aortic aneurysm. The objective of this study is to discuss the haemodynamic changes regarding aortocaval fistula and consider various management options. A literature search was undertaken on PubMed using appropriate search terms. Case series and reviews reporting presentation, diagnosis and operative management of aortocaval fistula were selected and discussed. We reached a conclusion that early identification improves surgical planning and reduces mortality. Major abdominal arteriovenous fistula repair appears to be a safer and more successful therapy with positive short and midterm outcomes. Aortocaval fistula care requires a more extensive patient series, so even better conclusions can be drawn.

Novel repair of acute Stanford type B aortic dissection using combined endovascular graft and transfemoral replacement of vascular plug.

We present successful treatment of dissected thoracoabdominal aorta using combined thoracic endovascular aortic repair and transfemoral replacement of Amplatzer™ vascular plug in a 38-year-old patient. Computed tomography angiography revealed a false lumen from the left subclavian artery to the left common iliac trunk, with re-entries connecting it to the true lumen of the aorta. We replaced the prosthetic endovascular graft just below the left subclavian artery to the top of the superior mesenteric artery. Amplatzer™ vascular plug was replaced below the diaphragm in a closed transfemoral procedure to prevent re-entry. The patient was discharged in good condition and 2 years postoperation imaging showed complete pseudoaneurysm closure.

Factors Affecting False Lumen Thrombosis In Type B Aortic Dissection. / Fatores que Afetam a Trombose da Falsa Luz na Dissecção Aórtica Tipo B.

BACKGROUND: Complete thrombosis of the false lumen facilitates remodeling of type B aortic dissection (TBAD). Morphological characteristics affect thrombosis in the false lumen. OBJECTIVES: Discuss the factors present before admission that influence false lumen thrombosis in patients with TBAD. METHODS: We studied 282 patients diagnosed with TBAD in our hospital between January 2008 and December 2017. We divided the subjects into a thrombotic group and a non-thrombotic group based on whether any thrombus was detectable in the false lumen. We analyzed the differences between the two groups with respect to clinical data, the vertical length of the dissection, and the diameter of the aorta. P values < 0.05 were considered statistically significantly different. RESULTS: Significant differences between the thrombotic group and non-thrombotic group were found with respect to age (53.92 ± 11.40 vs. 50.36 ± 10.71, p = 0.009) and proportion of patients with renal insufficiency (7.83% vs. 16.38%, p = 0.026). In zones 3-9, the true lumen diameter of the thrombotic group was significantly larger than in the non-thrombotic group (p < 0.05). Binary logistic regression analysis showed that true lumen diameter in zone 5 and renal insufficiency were independent predictors of false lumen thrombosis. CONCLUSIONS: Age and renal function were associated with thrombosis in the false lumen. Potentially, the difference between the diameter of the true lumen diameter and that of the false lumen may influence the thrombosis of the false lumen.

FUNDAMENTO: A trombose completa da falsa luz facilita a remodelação da dissecção aórtica tipo B (DATB). As características morfológicas afetam a trombose na falsa luz. OBJETIVOS: Discutir os fatores pré-admissão presentes, que influenciam a trombose da falsa luz em pacientes com DATB. METODOLOGIA: Ao todo, 282 pacientes diagnosticados com DATB em nosso hospital foram estudados, no período entre janeiro de 2008 e dezembro de 2017. Os indivíduos foram divididos em um grupo trombótico e um grupo não trombótico, com base na detecção de qualquer trombo na falsa luz. Analisamos as diferenças entre os dois grupos com relação aos dados clínicos, o comprimento vertical da dissecção e o diâmetro da aorta. Valores de p < 0,05 foram considerados estatisticamente diferentes de modo significativo. RESULTADOS: Diferenças significativas entre o grupo trombótico e o grupo não trombótico foram encontradas com relação à idade (53,92 ± 11,40 vs. 50,36 ± 10,71, p = 0,009) e proporção de pacientes com insuficiência renal (7,83% vs. 16,38%, p = 0,026). Nas zonas 3­9, o diâmetro da luz verdadeira do grupo trombótico foi significativamente maior do que no grupo não trombótico (p < 0,05). A análise de regressão logística binária mostrou que o diâmetro da luz verdadeira na zona 5 e a insuficiência renal foram preditores independentes de trombose da falsa luz. CONCLUSÕES: A idade e a função renal estiveram associadas à trombose na falsa luz. Potencialmente, a diferença entre o diâmetro da luz verdadeira e o da falsa luz pode influenciar na trombose da falsa luz.

Kommerell's Diverticulum in a Right-Sided Aortic Arch With an Aberrant Left Subclavian Artery Hybrid Repair.

BACKGROUND: Kommerell's diverticulum (KD) with a right aortic arch (RAA) and aberrant left subclavian artery (aLSCA) is a rare congenital anomaly of the aortic arch. Treatment is not well defined due to its uncommon presentation, with rupture and dissection risk rates of up to 53%. CASE SUMMARY: A 54-year-old male with a history of chronic obstructive pulmonary disease (COPD) and hypertension presented with difficulty breathing during exercise without dysphagia. Follow-up computerized tomography angiogram (CTA) revealed the presence of a RAA and aLSCA arising from the descending thoracic aorta with an adjacent 58 × 41-mm KD and tracheal and esophageal displacement. Due to the size of the KD, risk of rupture, unsuitable anatomy for total endovascular aortic repair (EVAR), and high COPD burden, the patient was planned to undergo a hybrid surgical repair. Left common carotid (LCCA) artery to LSCA bypass, full aortic debranching, LSCA embolization and percutaneous thoracic endovascular aortic repair (TEVAR) were performed. Successful device position and exclusion of the diverticulum and aneurysmal aorta were observed after completion thoracic aortogram. 18-month follow-up CTA demonstrated patency of the LSCA to LCCA bypass graft and arch vessel branches, as well as stable exclusion of the KD. Persistence of a type II endoleak originated at the right first posterior intercostal artery has been noted and is being followed conservatively since no sac growth has occurred. CONCLUSION: We highlight the presence of a KD with RAA and aberrant subclavian artery, a rare congenital anatomic variation of the aortic arch with complex anatomy. Surgical planning must be individualized according to comorbidities and anatomical variations identified on imaging and 3D reconstructions.

Ascending thoracic aortic aneurysm elongation occurs in parallel with dilatation in a nonsurgical population.

OBJECTIVES: Rapid diameter growth is a criterion for ascending thoracic aortic aneurysm repair; however, there are sparse data on aneurysm elongation rate. The purpose of this study was to assess aortic elongation rates in nonsyndromic, nonsurgical aneurysms to understand length dynamics and correlate with aortic diameter over time. METHODS: Patients with <5.5-cm aneurysms and computed tomography angiography imaging at baseline and 3-5 years follow-up underwent patient-specific three-dimensional aneurysm reconstruction using MeVisLab. Aortic length was measured along the vessel centreline between the annulus and aortic arch. Maximum aneurysm diameter was determined from imaging in a plane normal to the vessel centreline. Average rates of aneurysm growth were evaluated using the longest available follow-up. RESULTS: Over the follow-up period, the mean aortic length for 67 identified patients increased from 118.2 (95% confidence interval: 115.4-121.1) mm to 120.2 (117.3-123.0) mm (P = 0.02) and 15 patients (22%) experienced a change in length of ≥5% from baseline. The mean annual growth rate for length [0.38 (95% confidence interval: 0.11-0.65) mm/year] was correlated with annual growth rate for diameter [0.1 (0.03-0.2) mm/year] (rho = 0.30, P = 0.01). Additionally, annual percentage change in length [0.3 (0.1-0.5)%/year] was similar to percentage change in diameter [0.2 (0.007-0.4)%/year, P = 0.95]. CONCLUSIONS: Aortic length increases in parallel with aortic diameter at a similar percentage rate. Further work is needed to identify whether elongation rate is associated with dissection risk. Such studies may provide insight into why patients with aortic diameters smaller than surgical guidelines continue to experience dissection events.

Intraoperative computed tomography during fenestrated and branched endovascular aortic repair: a feasibility study.

BACKGROUND: Endovascular aortic repair with fenestrated or branched endografts is technically challenging, and proper intraoperative assessment of all stent graft components with only angiography and fluoroscopy can be difficult. Intraoperative computed tomography (CT) imaging can be a valuable aid for the operators in the evaluation of stent grafting results prior to completion of surgery. PURPOSE: To examine the feasibility of performing intraoperative CT imaging during fenestrated and branched endovascular aortic repair (f-bEVAR) under sterile conditions and with patients under general anesthesia. MATERIAL AND METHODS: Intraoperative CT imaging was performed in 10 patients undergoing elective aortic repair with fenestrated or branched endografts. Adverse events, time consumption for CT set-up and image acquisition, and additional radiation dose to the patient were recorded. CT image quality was graded. Immediate corrective maneuvers performed based on the CT findings was registered. RESULTS: There were no adverse events related to intraoperative CT imaging. The median additional operating time by including intraoperative CT was 16 min (interquartile range [IQR] = 12-19), comprising 7% of the median total operating time. The median estimated additional radiation dose to the patient was 4.8 mSv (IQR = 3.8-4.9). All intraoperative CT examinations were considered to be of sufficient quality for stent graft evaluation. No immediate corrective procedures were performed on the basis of CT findings in this study cohort. CONCLUSION: CT imaging intraoperatively during f-bEVAR is feasible with an acceptable increase in operating time and radiation dose.