Reconsidering the Impact of Endovascular Repair on Short-Term and Mid-Term Outcomes in Peripheral Arterial Disease: A Retrospective Analysis.

BACKGROUND: The aim of the study is to compare the short-term and medium-term outcomes in patients who underwent open repair (OR) or endovascular repair (ER) for peripheral arterial disease (PAD) also including stratifications based on severity and year of the first intervention. METHODS: We conducted an observational retrospective single-center cohort study. We evaluated patients with PAD that primarily underwent ER, OR, minor, and major amputations in a single center from 2005 to 2020. The patients were then subdivided according to the type of intervention (OR versus ER), and stratified according to the International Classification of Diseases 9 code reported in the operating documents and to the year intervention. Mortality, minor, and major amputation rates occurring at 30 days, 2 years, and 5 years after the first intervention were evaluated as primary outcomes and compared between patient groups in both stratifications. Moreover, Kaplan-Maier curves were analyzed for these outcomes. RESULTS: One thousand four hundred ninety two patients (67.0% males) with PAD were evaluated. Their clinical presentations were intermittent claudication in 51.4% of cases, rest pain in 16.8%, ulcers in 10.3%, and gangrene in 21.5%. Nine hundred ninety seven (66.8%) underwent OR and 495 (33.2%) ER as first intervention for PAD. No statistical differences were observed in terms of mortality in the 2 groups (OR versus ER, P = 1,000, P = 0.357, and P = 0.688 at 30 days, 2 years, and 5 years, respectively). The rate of minor amputations was significantly higher (P < 0.012, P < 0.002, and P < 0.007 at 30 days, 2 years, and 5 years, respectively) for ER group in any of the observed follow-up periods. Also, we have observed that OR and ER do not have any significant short-term and medium-term major amputation rate differences. CONCLUSIONS: In our experience, the impact of ER does not significantly change short-term and mid-term major outcomes in patients with PAD.

Use of target vessel ballooning to facilitate endovascular treatment in the case of branched endovascular aneurysm repair with a retrograde approach.

A case of a new technique for branched endovascular aneurysm repair with a retrograde approach and ostial stenosis of the target vessel is reported. An angioplasty balloon was placed within the target vessel and used to give added stability to catheter advancement to place the stiff guidewire needed for placement of a bridging stent graft. In brief, a standard guidewire was first placed inside the target vessel through the retrograde approach. Next, the balloon was placed from outside the stent graft, again through a contralateral retrograde approach. Then, the angioplasty balloon was inflated, and a support catheter was advanced to the balloon and then slowly deflated to allow the catheter to advance. Finally, the stiff guidewire was placed. Subsequently, the bridging stent was placed and deployed. This technique is feasible and can be used in selected cases to use a retrograde approach when ostial stenosis of the target vessel is present.

Observational study of endoluminal mural thrombotic apposition in popliteal artery aneurysm stenting and its relationship with stent-graft geometrical features.

Introduction: The development of intrastent thrombosis is one of the mechanisms related to medium- to long-term failure of endovascular treatment of popliteal artery aneurysm. The present study aims to investigate possible links between the development of endoluminal mural thrombotic apposition in the stented zone (EMTS) with both geometrical features of stent-graft(s) and time of follow-up. Methods: Patients with popliteal artery aneurysm who underwent endovascular treatment were recruited during the follow-up period. Segmentation of computed tomography angiography scan was performed to detect femoropopliteal artery lumen, leg bones, EMTS, and stent-graft(s). The following parameters were assessed: number, diameter, and length of stent-graft(s); and shape, volume, and length of thrombotic apposition within the stent(s). The spiral shape of the thrombotic apposition was evaluated as well. Results: Eighteen male patients were recruited in the study. EMTS was observed in 13 of them (72%) during the follow-up analysis. An average of 1.8 ± 0.79 stents-grafts were implanted per patient with a median diameter and length of 6.2 (1.9) mm and 125 (50) mm, respectively. The percentage of the stent length where EMTS was present was 42.1 on average (interquartile range: 42.4%) with a mean volume of 206.8 mm3. A positive correlation was found between the length and volume of EMTS (R-squared = 0.71, p < 0.01). Moreover, EMTS had a helical shape in 8/13 patients, with 4/5 with counterclockwise rotation with stent-grafts in the left leg and 3/3 with clockwise direction treated in the right leg. A higher frequency of EMTS was observed in patients with longer follow-up and higher risk factors, as well. Conclusions: EMTS is observed in most of the patients under analysis, especially in those with medium- to long-term follow-up. The pattern of such EMTS follows a helical shape having a direction that depends on which leg, right or left, is treated. Our results suggest a close surveillance of popliteal aneurysm stenting by follow-up examinations to control the onset and progression of EMTS.

Artificial Intelligence Application to Screen Abdominal Aortic Aneurysm Using Computed tomography Angiography.

The aim of our study is to validate a totally automated deep learning (DL)-based segmentation pipeline to screen abdominal aortic aneurysms (AAA) in computed tomography angiography (CTA) scans. We retrospectively evaluated 73 thoraco-abdominal CTAs (48 AAA and 25 control CTA) by means of a DL-based segmentation pipeline built on a 2.5D convolutional neural network (CNN) architecture to segment lumen and thrombus of the aorta. The maximum aortic diameter of the abdominal tract was compared using a threshold value (30 mm). Blinded manual measurements from a radiologist were done in order to create a true comparison. The screening pipeline was tested on 48 patients with aneurysm and 25 without aneurysm. The average diameter manually measured was 51.1 ± 14.4 mm for patients with aneurysms and 21.7 ± 3.6 mm for patients without aneurysms. The pipeline correctly classified 47 AAA out of 48 and 24 control patients out of 25 with 97% accuracy, 98% sensitivity, and 96% specificity. The automated pipeline of aneurysm measurements in the abdominal tract reported a median error with regard to the maximum abdominal diameter measurement of 1.3 mm. Our approach allowed for the maximum diameter of 51.2 ± 14.3 mm in patients with aneurysm and 22.0 ± 4.0 mm in patients without an aneurysm. The DL-based screening for AAA is a feasible and accurate method, calling for further validation using a larger pool of diagnostic images towards its clinical use.

Early Experience of Inner Branch Retrograde Cannulation With E-nside Branch Stent Graft for Thoracoabdominal Aortic Aneurysms.

PURPOSE: The aim of our study is to investigate the feasibility of retrograde cannulation using devices with inner branches (IB) for the endovascular treatment of thoracoabdominal aortic aneurysms (TAAAs). MATERIALS AND METHODS: A retrospective analysis using IB configuration with retrograde cannulation was carried out on TAAAs patients undergoing endovascular treatment. RESULTS: Seven patients underwent IB endovascular treatment with retrograde cannulation between September 2020 and November 2021. The mean age was 80.4 years and 4 patients were male. A total of 26 of 28 target vessels were cannulated by retrograde access with a technical success of 93% (2 of 26 target vessels). Two intra-procedural complications were observed (1 renal artery dissection and 1 collateral renal artery rupture). In total, 26 of 28 treated vessels were retrograde cannulated with a technical success of 93%. A total of 39 stent bridges were used (all Viabahn VBX devices). The mean duration of the procedure was 321±102 minutes, and the mean scan time was 134±62 minutes. Mortality at 30 days was observed in 1 case. During the follow-up, 1 stent bridge occlusion was observed without the need for reintervention. CONCLUSION: Retrograde cannulation can also be successfully performed in the case of inner branches. CLINICAL IMPACT: In inner branched cases, retrograde cannulation should be taken into consideration in particular cases or it could become the option of choice. Dedicated endovascular material available such as steerable catheters and latest generation covered stents is fundamental for the success of the treatment.

Endovascular aortic repair impact on myocardial contractility: A prospective study.

BACKGROUND: This study aimed to estimate if the altered sphygmic wave transmission may affect the left ventricular (LV) contractile function in patients undergoing endovascular aortic repair (EVAR). METHODS: A prospective single-centre study was carried out on consecutive patients undergoing EVAR for abdominal aortic aneurysm. A preoperative and 6-month single photon emission computed tomography (SPECT) with arterial stiffness measurement were performed to evaluate variations in pressure wave curve and myocardial perfusion parameters. RESULTS: From 2018 to 2020 a total of 16 patients were included in the study. Among the parameters evaluated, we found a measurable reduction of the reflected wave transit time from pre- to postoperative period, for both stress (115.13 ± 7.2 ms-111.1 ± 7.0 ms, p = .08) and rest SPECT acquisitions (115.3 ± 6.2 ms-112.2 ± 5.6 ms, p = .1). Unidirectional increase of both LV end-systolic volume (34 ± 9 mL-39 ± 8 mL, p = .02) and end-diastolic volume (85 ± 34 mL-89 ± 29 mL, p = .6) was also observed. Lastly, the ratio between the end-systolic pressure and the end-systolic volume (maximal systolic myocardial stiffness) decreased from 3.6 ± 1.5 mmHg/mL to 2.66 ± .74 mmHg/mL (p = .03). CONCLUSIONS: Our data showed that EVAR induced an altered transmission of the sphygmic wave associated with an early LV contractile impairment.

Temporary Reperfusion of the Aneurysm Sac as a Prevention of Spinal Cord Ischemia After Endovascular Treatment of Thoracoabdominal Aortic Aneurysm: Systematic Review and Meta-analysis.

BACKGROUND: Spinal cord ischemia (SCI) is still a feared complication for patients suffering from thoracoabdominal aortic aneurysm (TAAA) who undergo endovascular treatment. The aims of this work are to review the available literature on different reperfusion methods of the aneurysm sac, and to analyze whether the different reperfusion methods, also in combination with other factors, are effective in reducing SCI risk and if the impact varies with the patient's age. METHODS: PubMed/MEDLINE library was searched for studies published until November 2020 concerning TAAA, endovascular repair, and SCI preventive measures. Systematic review and meta-analysis were conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses criteria. Primary outcome consisted of correlation between endovascular repair techniques (type A: single step; type B: staged approach with reperfusion branches; type C: staged sequential approach with positioning of the thoracic component). A logistic-weighted regression for each event (SCI, transient, and permanent) was then performed with type of treatment, age, and interaction between them as input factors. Finally, another logistic-weighted regression was performed to analyze the other relevant factors for which observations are available together with the endovascular technique. RESULTS: Data from 53 studies with a total of 3095 patients were analyzed. Type A, type B, and type C endovascular strategies were adopted in 75%, 13%, and 12% of studied patients, respectively. Data showed that both type B and type C treatments are associated with lower risk of SCI, with a higher reduction of type C with respect to type B, although this positive trend is limited for elder patients. Moreover, a greater aortic diameter, a reduced aneurysm extent, and the absence of cerebrospinal fluid drainage positioning contribute to lower the risk of SCI. Concerning permanent SCI, both type B and type C are effective in reducing percentages for all ages, with type C treatment more beneficial for younger patients and type B for elder ones. CONCLUSION: According to the anatomy and the endovascular repair feasibility criteria, staged endovascular treatment appears to offer relevant advantages over single-step treatment in reducing the risk of SCI, regardless of the reperfusion method adopted.

Geometric Analysis of Complex Endovascular Treatment of a Successfully Completed Residual Post-Type A Aortic Dissection.

We describe a case of complex multistep endovascular treatment of a post-Type A thoracoabdominal dissected aneurysm. Volume analysis documents true and false lumen improvements during follow-up. Centerline tortuosity of the aorta and of the iliac arteries straightens after endovascular treatment completion. In addition, analysis of stent-graft remodeling reveals the stent-graft tendency to spring back to its original status together with a caudal migration of the fenestrated body.

Ischemia-reperfusion damage is attenuated by GQ-11, a peroxisome proliferator-activated receptor (PPAR)-α/γ agonist, after aorta clamping in rats.

INTRODUCTION: Ischemia-Reperfusion (I/R) damage is one of the major challenges in cardiothoracic surgeries and in a pathological manner, is identified by exacerbated damage signals resulted from blood supply restriction and subsequent flow restoration and re­oxygenation. I/R damage includes cellular dysfunction and death, impairing tissue and organ function. Inflammation and oxidative stress are known to underlie either ischemia or reperfusion, leaded by HIF, TNF-α, NF-κB, IL-6 and ROS formation. However, the available approaches to prevent I/R damage has been unsuccessful so far. As agonists of peroxisome-proliferation activation receptor (PPAR) are described as transcription factors related to anti-inflammatory factors, we proposed to observe the effects of novel dual agonist, GQ-11, in I/R-related damage. METHODS: Male, Wistar rats, 60 days age and 305 g body weight average were treated with vehicle, pioglitazone or GQ-11 (20 mg/kg) for 7 consecutive days and were submitted to aorta clamping for 30 min followed by 3 h of reperfusion. 18F-fluorodeoxyglucose (18F-FDG), an analog of glucose associated with inflammation when accumulated, was observed in liver and bowel by positron emission tomography (PET). RESULTS: GQ-11 decreased 18F-FDG uptake in liver and bowel when compared to vehicle and pioglitazone. The treatment also modulated inflammatory markers IL-10, TGF-ß, IL-6, IL1-ß, TNFα, and CCL-2, besides antioxidant enzymes such as catalase, GPx and SOD. CONCLUSION: Inflammation and oxidative stress showed to be important processes to be regulated in I/R in order to prevent exacerbated responses that leads to cell/tissue dysfunction and death. PPAR agonists - including GQ-11 - might be promising agents in a strategy to avoid tissue dysfunction and death after cardiothoracic surgeries.

Deep Learning to Automatically Segment and Analyze Abdominal Aortic Aneurysm from Computed Tomography Angiography.

PURPOSE: Although segmentation of Abdominal Aortic Aneurysms (AAA) thrombus is a crucial step for both the planning of endovascular treatment and the monitoring of the intervention's outcome, it is still performed manually implying time consuming operations as well as operator dependency. The present paper proposes a fully automatic pipeline to segment the intraluminal thrombus in AAA from contrast-enhanced Computed Tomography Angiography (CTA) images and to subsequently analyze AAA geometry. METHODS: A deep-learning-based pipeline is developed to localize and segment the thrombus from the CTA scans. The thrombus is first identified in the whole sub-sampled CTA, then multi-view U-Nets are combined together to segment the thrombus from the identified region of interest. Polygonal models are generated for the thrombus and the lumen. The lumen centerline is automatically extracted from the lumen mesh and used to compute the aneurysm and lumen diameters. RESULTS: The proposed multi-view integration approach returns an improvement in thrombus segmentation with respect to the single-view prediction. The thrombus segmentation model is trained over a training set of 63 CTA and a validation set of 8 CTA scans. By comparing the thrombus segmentation predicted by the model with the ground truth data, a Dice Similarity Coefficient (DSC) of 0.89 ± 0.04 is achieved. The AAA geometry analysis provided an Intraclass Correlation Coefficient (ICC) of 0.92 and a mean-absolute difference of 3.2 ± 2.4 mm, for the measurements of the total diameter of the aneurysm. Validation of both thrombus segmentation and aneurysm geometry analysis is performed over a test set of 14 CTA scans. CONCLUSION: The developed deep learning models can effectively segment the thrombus from patients affected by AAA. Moreover, the diameters automatically extracted from the AAA show high correlation with those manually measured by experts.

Renal Ischemia/Reperfusion Early Induces Myostatin and PCSK9 Expression in Rat Kidneys and HK-2 Cells.

During visceral interventions, the transient clampage of supraceliac aorta causes ischemia/reperfusion (I/R) in kidneys, sometime resulting in acute renal failure; preclinical studies identified redox imbalance as the main driver of I/R injury. However, in humans, the metabolic/inflammatory responses seem to prevail on oxidative stress. We investigated myostatin (Mstn) and proprotein convertase subtilisin/kexin type 9 (PCSK9), proatherogenic mediators, during renal I/R. Compared to sham-operated animals, the kidneys of rats who had experienced ischemia (30 min) had higher Mstn and PCSK9 expression after 4 h of reperfusion. After 24 h, they displayed tubular necrosis, increased nitrotyrosine positivity, and nuclear peroxisome proliferator-activated receptor gamma coactivator-1alpha relocation, markers of oxidative stress and mitochondria imbalance. Mstn immunopositivity was increased in tubuli, while PCSK9 immunosignal was depleted; systemically, PCSK9 was higher in plasma from I/R rats. In HK-2 cells, both ischemia and reperfusion enhanced reactive oxygen species production and mitochondrial dysfunction. H2O2 upregulated Mstn and PCSK9 mRNA after 1 and 3.5 h, respectively. Accordingly, ischemia early induced Mstn and PCSK9 mRNA; during reperfusion Mstn was augmented and PCSK9 decreased. Mstn treatment early increased PCSK9 expression (within 8 h), to diminish over time; finally, Mstn silencing restrained ischemia-induced PCSK9. Our study demonstrates that renal I/R enhances Mstn and PCSK9 expression and that Mstn induces PCSK9, suggesting them as therapeutic targets for vascular protection during visceral surgery.

Endovascular Versus Open Surgical Repair for Ruptured Descending Aortic Pathologies: A Systematic Review and Meta-Analysis of Observational Studies.

PURPOSE: Ruptured descending thoracic aorta (rDTA) is an harmful condition requiring emergent treatment. Thoracic endovascular aortic repair (TEVAR) is replacing the traditional open repair in the majority of descending thoracic aortic disease. An unanimous agreement regarding the optimal approach to treat rDTA has not been reached yet due to the lack of evidences supporting the improvement of long-term survival. The present meta-analysis of observational cohort studies aims to estimate the outcome of endovascular (TEVAR) versus surgical (OR) approach in the treatment of rDTA. METHODS: Prisma Statement for performing and reporting meta-analysis has been used. MEDLINE, Scopus and the Cochrane Library databases were searched. A meta-analysis of observational cohort studies that examined the outcomes after OR and TEVAR for the management of rDTA was performed. RESULTS: A total of 10,466 patients with rDTA were screened. Endovascular therapy was associated with a lower risk of in-hospital mortality compared with open repair (Risk Ratio[RR] 0.63; 95% CI0.57-0.70). The risk of stroke rate was not statistically different between endovascular versus open approach (RR0.86; 95% CI0.62-1.19). Endovascular treatment had benefits on paraplegia (RR0.70; 95% CI0.55-0.91) and other neurological complications (RR0.24; 95% CI0.10-0.56). TEVAR was associated with lower renal failure, cardiac complications and vascular injuries. Late mortality (Hazard Ratio[HR] 0.84; 95% CI0.63-1.13) and re-intervention rate (RR1.48; 95% CI0.80-2.74) were not significantly different between TEVAR and OR. CONCLUSIONS: TEVAR seems to offer advantages in terms of early mortality and complications rate. Moreover, data on late mortality and re-intervention are encouraging to consider endovascular treatment comparable to open repair for acute thoracic aorta emergency on long-term follow-up.

Initial Clinical Experience With a New Conformable Abdominal Aortic Endograft: Aortic Neck Coverage and Curvature Analysis in Challenging Aortic Necks.

OBJECTIVES: Aim of this work was to investigate precision of deployment and conformability of a new generation GORE EXCLUDER Conformable Endoprosthesis with active control system (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) by analyzing aortic neck coverage and curvature. METHODS: All consecutive elective patients affected by abdominal aortic aneurysm or aortoiliac aneurysm treated at our institution between November 2018 and June 2019 with the new CEXC Device were enrolled. Validated software was adopted to determine the available apposition surface area into the aortic neck, apposition of the endograft to the aortic wall, shortest apposition length (SAL), shortest distance between the endograft fabric and the lowest renal arteries (SFD) and between the endograft fabric and the contralateral renal artery (CFD). Pointwise centerline curvature was also computed. RESULTS: Twelve patients (10 men, median age 78 years (71.75, 81.0)) with available pre- and postoperative computed tomography angiography (CTA) were included. Technical success was obtained in all the cases. Preoperative median length of the proximal aortic neck was 16.1 mm (10.7, 21.7) and suprarenal (α) and infrarenal (ß) neck angulation were, respectively, 28.9° (15.7°, 47.5°) and 75.0° (66.9°, 81.4°). Postoperative median apposition surface coverage was 79% (69.25%, 90.75%) of the available apposition surface. SFD and CFD were 1.5 mm (0.75, 5.25) and 7 mm (4.5, 21.5), respectively. Average curvature over the infrarenal aorta decreased from 25 m-1 (21.75, 29.0) to 22.5 m-1 (18.75, 24.5) postoperatively (p=0.02). Maximum curvature did not decrease significantly from 64.5 m-1 (54.25, 92.0) to 62 m-1 (41.75, 71.5) (p=0.1). CONCLUSIONS: Our early experience showed that deployment of the CEXC Device is safe and effective for patients with challenging proximal aortic necks. Absence of significant changes between pre- and postoperative proximal aortic neck angulations and curvature confirms the high conformability of this endograft.

Prediction model of isolated iliac and abdominal aneurysms.

OBJECTIVES: We analyse the cardiovascular risk factors in patients undergoing screening for Isolated Iliac Aneurysm (IIA) and Abdominal Aortic Aneurysm (AAA) and propose a logistic regression model to indicate patients at risk of IIA and/or AAA. METHODS: A screening programme was carried out to identify the presence of aneurysm based on Duplex scan examination. Cardiovascular risk factors information was collected from each subject. A descriptive analysis for the incidence of IIA and AAA stratified by age and sex was carried out to evaluate factors incidence. A logistic regression model was developed to predict the probability of developing an aneurysm based on the observed risk factor levels. A threshold probability of aneurysm risk for a datum patient was also identified to effectively direct screening protocols to patients most at risk. RESULTS: A cohort of 10 842 patients was evaluated: 1.52% affected by IIA, 2.69% by AAA and 3.90% by at least one. Risk factors analysis showed that: IIA was correlated with cardiological status, diabetes, cardiovascular disease family history, and dyslipidaemia; AAA was correlated with cardiological status, body mass index, hypertension, and dyslipidaemia; diabetes and dyslipidaemia were the most relevant factors with at least one aneurysm. The prediction tool based on the logistic regression and the threshold probability predict the presence of IIA and AAA in 69.7% and 83.8% of cases, under k-fold cross-validation. CONCLUSIONS: The proposed regression model can represent a valid aid to predict IIA and AAA presence and to select patients to be screened.

Geometric Analysis to Determine Kinking and Shortening of Bridging Stents After Branched Endovascular Aortic Repair.

PURPOSE: To evaluate bridging stent geometry in patients who underwent branched endovascular aortic repair (B-EVAR) and to correlate the outcomes with intrinsic bridging stent characteristics aiming to identify the stent(s) that guarantees the best performance. METHODS: Pre-operative and post-operative computed tomography images of all patients undergoing B-EVAR between September 2016 and April 2019 were retrospectively analyzed. Following geometrical features were measured: target vessel take-off angle (TOA); longitudinal stent shortening; shape index (SI), intended as ratio between minimum and maximum diameter of the lumen cross sections, averaged on three segments: zone 1 (proximal stented zone), zone 2 (intermediate), and zone 3 (distal). RESULTS: Thirty-eight branches (8 right (RRA) and 8 left renal arteries (LRA), 11 superior mesenteric arteries (SMA), 11 celiac trunks (CTR)) were treated. Fluency (Bard Peripheral Vascular), COVERA (Bard Peripheral Vascular), and VBX (WLGore&Assoc) stent-grafts were implanted in 10, 12, and 16 branches, respectively. Pre-operative TOA was more acute in RRA and LRA when compared to CTR and SMA, and straightened in post-operative configuration (109.86 ± 28.65° to 150.27 ± 21.0°; P < 0.001). Comparable values of SI among the stent types were found in zone 1 (P = 0.08), whereas higher SI in VBX group was detected in zones 2 (P < 0.001) and 3 (P < 0.001). The VBX group was also the most affected by stent shortening (11.12 ± 5.65%; P = 0.001). CONCLUSION: Our early experience showed that the VBX stent offers greater stent circularity than the other devices even if a greater shortening has been observed drawing attention with regards to the decision of the nominal stent length.

COVID-19 Impact on Vascular Surgery Practice: Experience From an Italian University Regional Hub Center for Vascular Pathology.

BACKGROUND: The aim of the study is to evaluate the impact of COVID-19 pandemic on vascular surgery practice in a regional hub center for complex vascular disease. METHODS: This is an observational single-center study in which we collected clinical and surgical data during (P1) and after (P2) the COVID-19 outbreak and the lockdown measures implemented in Northern Italy. We compared those data with the two-month period before the pandemic (P0). RESULTS: Compared to P0, ambulatory activities were severely reduced during P1 and limited to hospitalized patients and outpatients with urgent criteria. We performed 61 operations (18 urgent and 43 elective), with a decrease in both aortic (-17.8%), cerebrovascular (-53.3%), and peripheral artery (-42.6%) disease treatments. We also observed a greater drop in open procedures (-53.2%) than in endovascular ones (-22%). All the elective patients were treated for notdeferrable conditions and they were COVID-19 negative at the ward admission screening; despite this one of them developed COVID19 during the hospital stay. Four COVID-19 positive patients were treated in urgent setting for acute limb ischemia. Throughout P2 we gradually rescheduled elective ambulatory (+155.5%) and surgical (+18%) activities, while remaining substantially lower than during P0 (respectively -45.6% and -25.7%). CONCLUSIONS: Despite COVID-19 pandemic, our experience shows that with careful patient's selection, dedicated prehospitalization protocol and proper use of personal protective equipment it is possible to guarantee continuity of care.

Ficolin-2 serum levels predict the occurrence of acute coronary syndrome in patients with severe carotid artery stenosis.

BACKGROUND AND PURPOSE: erosion of vulnerable atherosclerotic plaques may cause life-threatening thromboembolic complications. There is indeed an urgent need to recognize a clear-cut biomarker able to identify vulnerable plaques. Here, we focused on circulating proteins belonging to the lectin pathway (LP) of complement activation. METHODS: we analyzed mannose-binding lectin (MBL), ficolin-1, -2 and -3 (LP initiators) levels by ELISA in sera from n = 240 of an already published cohort of patients undergoing endarterectomy for severe carotid stenosis and followed-up until 18 months after surgery. Immunofluorescence followed by confocal and polarized light microscopy was used to detect LP initiator intraplaque localization. Spearman's rank test was drawn to investigate correlation between serum LP levels and circulating inflammatory proteins or intraplaque components. Survival analyses were then performed to test the predictive role of LP on long-term adverse outcome. RESULTS: ficolins, but not MBL, correlated positively with 1) high circulating levels of inflammatory markers, including MPO, MMP-8, MMP-9, ICAM-1, osteopontin, neutrophil elastase, and; 2) immune cell intraplaque recruitment. Immunofluorescence showed ficolins in calcified plaques and ficolin-2 in cholesterol-enriched plaque regions in association with macrophages. In the multivariate survival analysis, ficolin-2 serum levels predicted a major adverse cardiovascular event during the follow-up, independently of symptomatic status and inflammatory markers (hazard ratio 38.6 [95 % CI 3.9-385.2]). CONCLUSIONS: ficolins support intraplaque immune cell recruitment and inflammatory processes ultimately leading to plaque vulnerability. Especially for ficolin-2 a strong predictive value toward adverse cardiovascular events was demonstrated. This evidence offers potentially new pharmacological target to dampen the inflammatory mechanisms leading to plaque vulnerability.

Patient-specific computational fluid dynamics of femoro-popliteal stent-graft thrombosis.

Intra-stent thrombosis is one of the major failure modes of popliteal aneurysm endovascular repair, especially when the diseased arterial segment is long and requires overlapping stent-grafts having different nominal diameters in order to accommodate the native arterial tapering. However, the interplay between stent sizing, post-operative arterial tortuosity, luminal diameter, local hemodynamics, and thrombosis onset is not elucidated, yet. In the present study, a popliteal aneurysm was treated with endovascular deployment of two overlapped stent-grafts, showing intra-stent thrombosis at one-year follow-up examination. Patient-specific computational fluid-dynamics analyses including straight- and bent-leg position were performed. The computational fluid-dynamics analysis showed that the overlapping of the stent-grafts induces a severe discontinuity of lumen, dividing the stented artery in two regions: the proximal part, affected by thrombosis, is characterized by larger diameter, low tortuosity, low flow velocity, low helicity, and low wall shear stress; the distal part presents higher tortuosity and smaller lumen diameter promoting higher flow velocity, higher helicity, and higher wall shear stress. Moreover, leg bending induces an overall increase of arterial tortuosity and reduces flow velocity promoting furtherly the luminal area exposed to low wall shear stress.

3D Automatic Segmentation of Aortic Computed Tomography Angiography Combining Multi-View 2D Convolutional Neural Networks.

PURPOSE: The quantitative analysis of contrast-enhanced Computed Tomography Angiography (CTA) is essential to assess aortic anatomy, identify pathologies, and perform preoperative planning in vascular surgery. To overcome the limitations given by manual and semi-automatic segmentation tools, we apply a deep learning-based pipeline to automatically segment the CTA scans of the aortic lumen, from the ascending aorta to the iliac arteries, accounting for 3D spatial coherence. METHODS: A first convolutional neural network (CNN) is used to coarsely segment and locate the aorta in the whole sub-sampled CTA volume, then three single-view CNNs are used to effectively segment the aortic lumen from axial, sagittal, and coronal planes under higher resolution. Finally, the predictions of the three orthogonal networks are integrated to obtain a segmentation with spatial coherence. RESULTS: The coarse segmentation performed to identify the aortic lumen achieved a Dice coefficient (DSC) of 0.92 ± 0.01. Single-view axial, sagittal, and coronal CNNs provided a DSC of 0.92 ± 0.02, 0.92 ± 0.04, and 0.91 ± 0.02, respectively. Multi-view integration provided a DSC of 0.93 ± 0.02 and an average surface distance of 0.80 ± 0.26 mm on a test set of 10 CTA scans. The generation of the ground truth dataset took about 150 h and the overall training process took 18 h. In prediction phase, the adopted pipeline takes around 25 ± 1 s to get the final segmentation. CONCLUSION: The achieved results show that the proposed pipeline can effectively localize and segment the aortic lumen in subjects with aneurysm.

Geometrical Evaluation of Aortic Sac Remodeling During Two-Step Thoracoabdominal Aortic Aneurysm Endovascular Repair.

BACKGROUND: The present study evaluates aneurysmal sac remodeling and the loss of the intercostal arteries after the first step of staged treatment of thoracoabdominal aortic aneurysms (TAAAs). The purpose of this approach is to keep the aneurysmal sac temporarily perfused to induce progressive thrombosis of the aneurysm while simultaneously allowing the spinal cord to establish adequate perfusion thereby promoting the development of collateral circulation. METHODS: All patients with type II or type III TAAAs, having undergone 2-step endovascular treatment with at least a 2-branch endoprosthesis at our institution between April 2017 and May 2019, were retrospectively evaluated. Thirty-day mortality and spinal cord ischemia was assessed. The mean number of the intercostal and lumbar arteries, coverage length between the left subclavian artery and the stent graft proximal landing zone, total volume of the aneurysmal sac, lumen volume, and thrombosis volume were measured by preoperative and first-step postoperative computed tomography angiography. Patients were also grouped based on the chosen endoprosthesis (group A: double-branch aneurysmal sac reperfusion; group B: single-branch aneurysmal sac reperfusion). RESULTS: Eleven patients (mean age: 76.5 years; range: 61-86) were considered. No 30-day mortality was observed after the first-step procedure, and 1 patient died after second-step treatment. No permanent paraplegia was observed after either the first or second endovascular steps. The lumen volume significantly decreased (27%; P < 0.001) after first-step endovascular treatment although there was a significant increase in aneurysm thrombosis (34% to 54%). The mean number of the intercostal arteries decreased from 19.7 to 9.3 (P < 0.001) after first-step endovascular treatment. Volume variations and percentage of intercostal loss did not significantly differ between the 2 groups. CONCLUSIONS: Although aneurysm volume continued to increase after first-step treatment, two-step endovascular treatment is a feasible alternative to reduce the risk of severe ischemia in patients with extended TAAAs.