Patient-specific finite element simulation of peripheral artery percutaneous transluminal angioplasty to evaluate the procedure outcome without stent implantation.

The purpose of this work is to present a patient-specific (PS) modeling approach for simulating percutaneous transluminal angioplasty (PTA) endovascular treatment and assessing the balloon sizing influence on short-term outcomes in peripheral arteries, i.e. without stent implantation. Two 3D PS stenosed femoral artery models, one with a dominant calcified atherosclerosis while the other with a lipidic plaque, were generated from pre-operative computed tomography angiography images. Elastoplastic constitutive laws were implemented within the plaque and artery models. Implicit finite element method (FEM) was used to simulate the balloon inflation and deflation for different sizings. Besides vessel strains, results were mainly evaluated in terms of the elastic recoil ratio (ERR) and lumen gain ratio (LGR) attained immediately after PTA. Higher LGR values were shown within the stenosed region of the lipidic patient. Simulated results also showed a direct and quantified correlation between balloon sizing and LGR and ERR for both patients after PTA, with a more significant influence on the lumen gain. The max principal strain values in the outer arterial wall increased at higher balloon sizes during inflation as well, with higher rates of increase when the plaque was calcified. Results show that our model could serve in finding a compromise for each stenosis type: maximizing the achieved lumen gain after PTA, but at the same time without damaging the arterial tissue. The proposed methodology can serve as a step toward a clinical decision support system to improve angioplasty balloon sizing selection prior to the surgery.

Stretched reconstruction based on 2D freehand ultrasound for peripheral artery imaging.

PURPOSE: Endovascular revascularization is becoming the established first-line treatment of peripheral artery disease (PAD). Ultrasound (US) imaging is used pre-operatively to make the first diagnosis and is often followed by a CT angiography (CTA). US provides a non-invasive and non-ionizing method for the visualization of arteries and lesion(s). This paper proposes to generate a 3D stretched reconstruction of the femoral artery from a sequence of 2D US B-mode frames. METHODS: The proposed method is solely image-based. A Mask-RCNN is used to segment the femoral artery on the 2D US frames. In-plane registration is achieved by aligning the artery segmentation masks. Subsequently, a convolutional neural network (CNN) predicts the out-of-plane translation. After processing all input frames and re-sampling the volume according to the vessel's centerline, the whole femoral artery can be visualized on a single slice of the resulting stretched view. RESULTS: 111 tracked US sequences of the left or right femoral arteries have been acquired on 18 healthy volunteers. fivefold cross-validation was used to validate our method and achieve an absolute mean error of 0.28 ± 0.28 mm and a median drift error of 8.98%. CONCLUSION: This study demonstrates the feasibility of freehand US stretched reconstruction following a deep learning strategy for imaging the femoral artery. Stretched views are generated and can give rich diagnosis information in the pre-operative planning of PAD procedures. This visualization could replace traditional 3D imaging in the pre-operative planning process, and during the pre-operative diagnosis phase, to identify, locate, and size stenosis/thrombosis lesions.

Prospective Multicentre Cohort Study of Fenestrated and Branched Endografts After Failed Endovascular Infrarenal Aortic Aneurysm Repair with Type Ia Endoleak.

OBJECTIVE: Failed endovascular infrarenal aortic aneurysm repair (EVAR) due to development of late type Ia endoleak exposes patients to the risk of rupture and should be treated. The purpose of this study was to evaluate the results of fenestrated/branched EVAR (F/BEVAR) for treatment of failed EVAR with type Ia endoleak. METHODS: From January 2010 to December 2019, a prospective multicentre study was conducted (ClinicalTrials.gov identifier: NCT04532450) that included 85 consecutive patients who had undergone F/BEVAR to treat a type Ia endoleak following EVAR. The primary outcome was overall freedom from any re-intervention or death related to the F/BEVAR procedure. RESULTS: In 30 cases (35%) EVAR was associated with a short < 10 mm or angulated (> 60°) infrarenal aortic neck, poor placement of the initial stent graft (n = 3, 4%), sizing error (n = 2, 2%), and/or stent graft migration (n = 7, 8%). Type Ia endoleak was observed after a period of 59 ± 25 months following EVAR. The authors performed 82 FEVAR (96%) and three BEVAR (4%) procedures with revascularisation of 305 target arteries. Overall technical success was 94%, with three failures including one persistent Type Ia endoleak and two unsuccessful stent graft implantations. Intra-operative target artery revascularisation was successful in 303 of 305 attempts. The in hospital mortality rate was 5%. Cardiac, renal and pulmonary complications occurred in 6%, 14%, and 7% of patients, respectively. Post-operative spinal cord ischaemia occurred in four patients (4.7%). At three years, the survival rate was 64% with overall freedom from any re-intervention or aneurysm related death of 40%, and freedom from specific F/BEVAR re-intervention of 73%. At three years, the secondary patency rate of the target visceral arteries was 96%. During follow up, 27 patients (33%) required a revision procedure of the fenestrated (n = 11) or index EVAR stent graft (n = 16), including six open conversions. CONCLUSION: While manufactured F/BEVAR was effective in treating type Ia endoleak in patients with failed EVAR, it was at the cost of a number of secondary endovascular and open surgical procedures.

Current results of left gonadal vein transposition to treat nutcracker syndrome.

OBJECTIVE: Nutcracker syndrome can cause disabling chronic pain requiring surgical intervention. At present, data describing a straightforward management approach are lacking. Transposition of the left gonadal vein is one of the surgical therapeutic alternatives. The aim of the present study was to describe our clinical results with gonadal vein transposition. METHODS: All 11 patients from three centers who had undergone left gonadal vein transposition for nutcracker syndrome from 2016 to 2019 were retrospectively included. The surgical cases were mainly selected according to the morphologic criteria of the left gonadal vein. The diameter and length dictated the type of approach (laparotomy or retroperitoneal) and the transposition level. A minimally invasive retroperitoneal approach was preferred. Pain was assessed using a numeric rating scale. RESULTS: We included 11 patients (10 women) with a median age of 35 years (range, 25-69). Preoperative computed tomography angiography showed anterior nutcracker syndrome in 10 patients (91%). All 11 patients had experienced lower back and/or pelvic pain, which was associated with pelvic congestion syndrome in 6 patients (55%) and hematuria in 5 patients (45%). The median preoperative numeric rating scale score for pain was 7.0 (range, 3.5-10.0) and 6.0 (range, 3.5-8.0) for lower back pain and pelvic pain, respectively. At the level of the iliac vein crossing (external or common), the median diameter of the left gonadal vein was 7.87 mm (range, 6.45-11.28). The left gonadal vein was transposed to the inferior vena cava in one case (9%), the left external iliac vein in five (45%), and the left common iliac vein in five cases (45%). The median in-hospital stay was 4 days (range, 2-20 days). Two early complications (18%) requiring surgical revision occurred: one of active bleeding and one hematoma. The median follow-up was 15 months (range, 6-44 months). The median postoperative pain score was 1.0 (range, 0.0-4.0) and 0.0 (range, 0.0-6.0) for lower back and pelvic pain, respectively. Incisional and/or neuropathic pain was noted, with a median score of 3.5 (range, 1.0-6.0) in seven patients (64%). Two late complications (18%) were observed: one case of thrombosis and one case of anastomotic stenosis. The hematuria had disappeared in all patients who had presented with it initially. CONCLUSIONS: Left gonadal vein transposition can be proposed as a first approach if the diameter of the left gonadal vein is sufficient to perform the anastomosis. It is an easily achievable, minimally invasive alternative that achieves satisfactory results without the use of foreign material.

Use of rifampicin and graft removal are associated with better outcomes in prosthetic vascular graft infection.

OBJECTIVES: Prosthetic vascular graft infection (PVGI) is a very severe disease. We aimed to determine the factors associated with treatment failure. METHODS: Patients admitted to two University Hospitals with PVGI were included in this retrospective study. PVGI was classified as possible, probable or proven according to an original set of diagnostic criteria. We defined treatment failure if one of the following events occurred within the first year after PVGI diagnosis: death and infection recurrence due to the same or another pathogen. RESULTS: One hundred and twelve patients were diagnosed with possible (n = 26), probable (n = 22) and proven (n = 64) PVGI. Bacterial documentation was obtained for 81% of patients. The most frequently identified pathogen was Staphylococcus aureus (n = 39). Surgery was performed in 96 patients (86%). Antibiotics were administered for more than 6 weeks in 41% of patients. Treatment failure occurred in 30 patients (27.5%). The factors associated with a lower probability of treatment failure were total removal of the infected graft (OR = 0.2, 95% CI [0.1-0.6]), rifampicin administration (OR = 0.3 [0.1-0.9]) and possible PVGI according to the GRIP criteria (OR = 0.3 [0.1-0.9]). CONCLUSIONS: Treatment failure occurred in 27.5% of patients with PVGI. Total removal of the infected graft and rifampicin administration were associated with better outcomes.

Editor's Choice - A Cost Effectiveness Analysis of Outpatient versus Inpatient Hospitalisation for Lower Extremity Arterial Disease Endovascular Revascularisation in France: A Randomised Controlled Trial.

OBJECTIVE: The AMBUVASC trial evaluated the cost effectiveness of outpatient vs. inpatient hospitalisation for endovascular repair of lower extremity arterial disease (LEAD). METHODS: AMBUVASC was a national multicentre, prospective, randomised controlled trial conducted in nine public and two private French centres. The primary endpoint was the incremental cost effectiveness ratio (ICER), defined by cost per quality adjusted life year (QALY). Analysis was conducted from a societal perspective, excluding indirect costs, and considering a one month time horizon. RESULTS: From 16 February 2016 to 29 May 2017, 160 patients were randomised (80 per group). A modified intention to treat analysis was performed with 153 patients (outpatient hospitalisation: n = 76; inpatient hospitalisation: n = 77). The patients mainly presented intermittent claudication (outpatient arm: 97%; inpatient arm: 92%). Rates of peri-operative complications were 20% (15 events) and 18% (14 events) for the outpatient and inpatient arms respectively (p = .81). Overall costs (difference: €187.83; 95% confidence interval [CI] -275.68-651.34) and QALYs (difference: 0.00277; 95% CI -0.00237 - 0.00791) were higher for outpatients due to more re-admissions than the inpatient arm. The mean ICER was €67 741 per QALY gained for the base case analysis with missing data imputed using multiple imputation by predictive mean matching. The outpatient procedure was not cost effective for a willingness to pay of €50 000 per QALY and the probability of being cost effective was only 59% for a €100 000/QALY threshold. CONCLUSION: Outpatient hospitalisation is not cost effective compared with inpatient hospitalisation for endovascular repair of patients with claudication at a €50 000/QALY threshold.

Fusion Imaging with a Mobile C-Arm for Peripheral Arterial Disease.

BACKGROUND: Fusion imaging makes it possible to improve endovascular procedures and is mainly used in hybrid rooms for aortic procedures. The objective of this study was to evaluate the feasibility of fusion imaging for femoropopliteal endovascular procedures with a mobile flat plane sensor and dedicated software to assist endovascular navigation. MATERIALS AND METHODS: Between May and December 2017, 41 patients requiring femoropopliteal endovascular revascularization were included. Interventions were carried out in a conventional surgical room equipped with a mobile plane sensor (Cios Alpha, Siemens). The numerical video stream was transmitted to an angionavigation station (EndoNaut (EN), Therenva). The software created an osseous and arterial panorama of the treated limb from the angiographies carried out at the beginning of procedure. After each displacement of the table, the software relocated the current image on the osseous panorama, with 2D-2D resetting, and amalgamated the mask of the arterial panorama. The success rates of creation of osseous and arterial panorama and the success of relocation were evaluated. The data concerning irradiation, the volume of contrast (VC) injected, and operative times were recorded. RESULTS: Osseous panoramas could be automatically generated for the 41 procedures, without manual adjustment in 33 cases (80.5%). About 35 relocations based on a 2D-2D resetting could be obtained in the 41 procedures, with a success rate of 85%. The causes of failure were a change in table height or arch angulation. The average duration of intervention was 74.5 min. The irradiation parameters were duration of fluoroscopy 17.8 ± 13.1 min, air kerma 80.5 ± 68.4 mGy, and dose area product 2140 ± 1599 µGy m2. The average VC was 24.5 ± 14 mL. CONCLUSIONS: This preliminary study showed that fusion imaging is possible in a nonhybrid room for peripheral procedures. Imagery of mobile C-arms can be improved for femoropopliteal endovascular procedures without heavy equipment. These imagery tools bring an operative comfort and could probably reduce irradiation and the injected VC. The clinical benefit must be evaluated in more patients in a randomized comparative study with a rigorous methodology.

Use of Numerical Simulation to Predict Iliac Complications During Placement of An Aortic Stent Graft.

BACKGROUND: During endovascular aneurysm repair (EVAR), complex iliac anatomy is a source of complications such as unintentional coverage of the hypogastric artery. The aim of our study was to evaluate ability to predict coverage of the hypogastric artery using a biomechanical model simulating arterial deformations caused by the delivery system. METHODS: The biomechanical model of deformation has been validated by many publications. The simulations were performed on 38 patients included retrospectively, for a total of 75 iliac arteries used for the study. On the basis of objective measurements, two groups were formed: one with "complex" iliac anatomy (n = 38 iliac arteries) and the other with "simple" iliac anatomy (n = 37 iliac arteries). The simulation enabled measurement of the lengths of the aorta and the iliac arteries once deformed by the device. Coverage of the hypogastric artery was predicted if the deformed renal/iliac bifurcation length (Lpre) was less than the length of the implanted device (Lstent-measured on the postoperative computed tomography [CT]) and nondeformed Lpre was greater than Lstent. RESULTS: Nine (12%) internal iliac arteries were covered unintentionally. Of the coverage attributed to perioperative deformations, 1 case (1.3%) occurred with simple anatomy and 6 (8.0%) with complex anatomy (P = 0.25). All cases of unintentional coverage were predicted by the simulation. The simulation predicted hypogastric coverage in 35 cases (46.7%). There were therefore 26 (34.6%) false positives. The simulation had a sensitivity of 100% and a specificity of 60.6%. On multivariate analysis, the factors significantly predictive of coverage were the iliac tortuosity index (P = 0.02) and the predicted margin between the termination of the graft limb and the origin of the hypogastric artery in nondeformed (P = 0.009) and deformed (P = 0.001) anatomy. CONCLUSIONS: Numerical simulation is a sensitive tool for predicting the risk of hypogastric coverage during EVAR and allows more precise preoperative sizing. Its specificity is liable to be improved by using a larger cohort.

Fusion Imaging for EVAR with Mobile C-arm.

BACKGROUND: Fusion imaging is a technique that facilitates endovascular navigation but is only available in hybrid rooms. The goal of this study was to evaluate the feasibility of fusion imaging with a mobile C-arm in a conventional operating room through the use of an angionavigation station. METHODS: From May 2016 to June 2017, the study included all patients who underwent an aortic stent graft procedure in a conventional operating room with a mobile flat-panel detector (Cios Alpha, Siemens) connected to an angionavigation station (EndoNaut, Therenva). The intention was to perform preoperative 3D computerized tomography/perioperative 2D fluoroscopy fusion imaging using an automatic registration process. Registration was considered successful when the software was able to correctly overlay preoperative 3D vascular structures onto the fluoroscopy image. For EVAR, contrast dose, operation time, and fluoroscopy time (FT) were compared with those of a control group drawn from the department's database who underwent a procedure with a C-arm image intensifier. RESULTS: The study included 54 patients, and the procedures performed were 49 EVAR, 2 TEVAR, 2 IBD, and 1 FEVAR. Of the 178 registrations that were initialized, it was possible to use the fusion imaging in 170 cases, that is, a 95.5% success rate. In the EVAR comparison, there were no difference with the control group (n = 103) for FT (21.9 ± 12 vs. 19.5 ± 13 min; P = 0.27), but less contrast agent was used in the group undergoing a procedure with the angionavigation station (42.3 ± 22 mL vs. 81.2 ± 48 mL; P < 0.001), and operation time was shorter (114 ± 44 vs. 140.8 ± 38 min; P < 0.0001). CONCLUSIONS: Fusion imaging is feasible with a mobile C-arm in a conventional operating room and thus represents an alternative to hybrid rooms. Its clinical benefits should be evaluated in a randomized series, but our study already suggests that EVAR procedures might be facilitated with an angionavigation system.

An improved nonlinear diffusion in Laplacian pyramid domain for cone beam CT denoising during image-guided vascular intervention.

BACKGROUND: Cone-beam computed tomography (CBCT) acquisition during endovascular aneurysm repair is an emergent technology with more and more applications. It may provide 3-D information to achieve guidance of intervention. However, there is growing concern on the overall radiation doses delivered to patients, thus a low dose protocol is called when scanning. But CBCT images with a low dose protocol are degraded, resulting in streak artifacts and decreased contrast-to-noise ratio (CNR). In this paper, a Laplacian pyramid-based nonlinear diffusion is proposed to improve the quality of CBCT images. METHOD: We first transform the CBCT image into its pyramid domain, then a modified nonlinear diffusion is performed in each level to remove noise across edges while keeping edges as far as possible. The improved diffusion coefficient is a function of the gradient magnitude image; the threshold in the modified diffusion function is estimated using the median absolute deviation (MAD) estimator; the time step is automatically determined by iterative image changes and the iteration is stopped according to mean absolute error between two adjacent diffusions. Finally, we reconstruct the Laplacian pyramid using the processed pyramid images in each level. RESULT: Results from simulation show that the filtered image from the proposed method has the highest peak signal-noise ratio (81.92), the highest correlation coefficient (99.77%) and the lowest mean square error (27.61), compared with the other four methods. In addition, it has highest contrast-to-noise ratio and sharpness in ROIs. Results from real CBCT images show that the proposed method shows better smoothness in homogeneous regions meanwhile keeps bony structures clear. CONCLUSION: Simulation and patient studies show that the proposed method has a good tradeoff between noise/artifacts suppression and edge preservation.

Predictive Factors of Silent Brain Infarcts after Asymptomatic Carotid Endarterectomy.

BACKGROUND: The optimization of medical treatment regularly challenges the role of carotid surgery for asymptomatic patients. Current research seeks to determine which of these patients will benefit most from surgery. The goal of this study was to identify in a multicenter study, using magnetic resonance imaging (MRI), the risk factors for postoperative silent cerebral ischemic lesions after carotid surgery for asymptomatic stenosis. METHODS: The multicenter, retrospective study included patients with asymptomatic severe carotid stenosis suitable for surgical treatment and who did not have a history of cerebral ischemia. A diffusion MRI scan was performed the day before and in the 3 days after the procedure. An analysis by an independent neuroradiologist determined the presence of preoperative silent ischemia and the appearance of new lesions postoperatively. The analysis also took into account the plaque type, lesions of supra-aortic trunks, the circle of Willis, the type of surgery, and anesthesia, shunt use, and clamp time. RESULTS: Between April 2011 and November 2015, 141 patients were included. The mean degree of carotid stenosis in the patients who underwent surgery was 78.2% ± 6.5, with 9 (6.4%) cases of contralateral stenosis ≥70% and 6 (4.3%) of which were thrombosis. The circle of Willis was incomplete in 23 (16.3%) patients. Twenty-one (14.9%) plaques were of high embolic risk. The preoperative MRI found 34 (24.1%) patients with embolic ischemic lesions. The majority of procedures were eversions performed under general anesthesia, 7 (5%) required a shunt, and the mean clamp time was 39 ± 16 min. The postoperative MRI revealed that 10 (7%) patients had a new ischemic lesion on the operated side. None of these lesions were symptomatic. On multivariate analysis, the risk factors for appearance of a new ischemic lesion on the operated side were significant severe stenosis of the vertebral artery ipsilateral to the lesion (odds ratio [OR] = 9.2, 95% confidence interval [CI] [2.1-39.8], P = 0.003) and insertion of a shunt (OR = 9.1, 95% CI [1.1-73.1], P = 0.039). The 30-day follow-up showed one death at D4 due to hemorrhagic stroke on the operated side and one contralateral stroke. None of the study patients had a myocardial infarction. CONCLUSIONS: In this multicenter study, the rate of silent ischemic lesions in asymptomatic carotid surgery showed 43.3% of preoperative silent ischemic lesions and 9.2% of new silent lesions after surgery. The use of a shunt and presence of ipsilateral vertebral stenosis are risk factors for perioperative embolism.

A hybrid image fusion system for endovascular interventions of peripheral artery disease.

PURPOSE: Interventional endovascular treatment has become the first line of management in the treatment of peripheral artery disease (PAD). However, contrast and radiation exposure continue to limit the feasibility of these procedures. This paper presents a novel hybrid image fusion system for endovascular intervention of PAD. We present two different roadmapping methods from intra- and pre-interventional imaging that can be used either simultaneously or independently, constituting the navigation system. METHODS: The navigation system is decomposed into several steps that can be entirely integrated within the procedure workflow without modifying it to benefit from the roadmapping. First, a 2D panorama of the entire peripheral artery system is automatically created based on a sequence of stepping fluoroscopic images acquired during the intra-interventional diagnosis phase. During the interventional phase, the live image can be synchronized on the panorama to form the basis of the image fusion system. Two types of augmented information are then integrated. First, an angiography panorama is proposed to avoid contrast media re-injection. Information exploiting the pre-interventional computed tomography angiography (CTA) is also brought to the surgeon by means of semiautomatic 3D/2D registration on the 2D panorama. Each step of the workflow was independently validated. RESULTS: Experiments for both the 2D panorama creation and the synchronization processes showed very accurate results (errors of 1.24 and [Formula: see text] mm, respectively), similarly to the registration on the 3D CTA (errors of [Formula: see text] mm), with minimal user interaction and very low computation time. First results of an on-going clinical study highlighted its major clinical added value on intraoperative parameters. CONCLUSION: No image fusion system has been proposed yet for endovascular procedures of PAD in lower extremities. More globally, such a navigation system, combining image fusion from different 2D and 3D image sources, is novel in the field of endovascular procedures.

The FREEDOM Study: A Pilot Study Examining the Feasibility and Safety of Early Walking following Femoral Manual Compression after Endovascular Interventions Using 5F Sheath-Compatible Devices.

BACKGROUND: Increasing prevalence of peripheral arterial disease (PAD) burning and pressure to reduce costs and promote patient empowerment make outpatient endovascular procedures an attractive alternative to conventional hospitalization. For outpatient peripheral endovascular procedures, femoral manual compression could replace the use of arterial closure devices for small-bore punctures. Presently, safety and feasibility evidence for femoral manual compression is still lacking. FREEDOM is a pilot study designed to demonstrate the feasibility and safety of early walking after femoral manual puncture point compression following a therapeutic endovascular procedure for PAD. METHODS: From May to August 2015, all patients requiring endovascular treatment for PAD were prospectively screened. Those patients that received therapeutic endovascular procedures involving retrograde femoral punctures with a 5F sheath were included. Manual compression and pressure dressing of the femoral puncture points was applied. The primary end point was defined as the walking ability 5 hr after index procedure (H5), which was assessed by a walk test. RESULTS: In total, 129 consecutive patients were screened, and 30 patients met the study criteria. The mean age was 66 ± 11 years. The mean duration of the procedure and of the manual compression was 63 ± 24 min and 12.8 ± 4 min, respectively. At 5 hr following the procedure, 97% of the patients were able to walk 100 m. Two patients failed to walk due to cardiac arrhythmia and to a false aneurysm at the femoral puncture site. No further complications were observed at 1 month, and quality of life assessed by EQ-5D test was significantly increased compare to baseline (72.3 vs. 60.4; P = 0.001). CONCLUSIONS: This pilot study demonstrated the benefits of manual compression to close arterial punctures over procedures using 5F shealth-compatible endovascular devices. A sufficiently powered randomized controlled trial is needed to further characterize the potential benefits of manual compression following use of low-profile devices.

Comparison of Radiation Exposure during Endovascular Treatment of Peripheral Arterial Disease with Flat-Panel Detectors on Mobile C-arm versus Fixed Systems.

BACKGROUND: Flat-panel detectors on mobile C-arm (MC-arm) systems are currently challenging fixed C-arm (FC-arm) systems used in hybrid operating rooms. MC-arm systems offer an alternative to FC-arm systems in the endovascular treatment of peripheral arterial disease (PAD) but their efficiency has not been evaluated comparatively. METHODS: Two series of patients undergoing arteriography with intention to treat were included. Each series consisted of 2 nonrandomized groups: an MC-arm group and an FC-arm group. Series 1 evaluated exposure to the patient (MC-arm, n = 113; FC-arm, n = 206) while series 2 evaluated exposure to patients and also health care personnel (MC-arm, n = 24; FC-arm, n = 76). The primary end points for evaluating exposure were air kerma (AK, in mGy) for patients and effective dose for health care personnel (in µSv). RESULTS: After adjustment for the effect of body mass index (analysis of covariance test), AK was found to be lower in the MC-arm group than in the FC-arm group (124.1 ± 142 vs. 173.3 ± 248.7, P = 0.025). There was no difference between the groups with regard to effective dose recorded for senior surgeons or for operating room nurses. However, a higher effective dose was recorded by the MC-arm group external dosimeter for the trainee resident and for nurse anesthetists. CONCLUSIONS: In endovascular treatment of lower limb PAD, use of an FC-arm system is associated with more radiation exposure to the patient than an MC-arm system. However, this type of imaging system does not appear to affect exposure to health care personnel.

Impact of Vascular Calcifications on Long Femoropopliteal Stenting Outcomes.

BACKGROUND: Vascular calcifications (VCs) may be a prognostic factor for outcome after endovascular treatment of peripheral arterial disease (PAD). Semiquantitative analysis with X-ray imaging is the main limiting factor for assessing VCs. The aim of the present study was to find a correlation between the amount of VC with computed tomography (CT) scan quantification and midterm results of endovascular treatment of Trans-Atlantic Inter-Society Consensus C/D femoropopliteal (FP) lesions. METHODS: Patients belonging to 2 previously published registries (STELLA and STELLA PTX) and who underwent a preoperative CT scan were retrospectively included in the study. VC quantification was performed with a dedicated workstation (EndoSize, Therenva) on the basis of Hounsfield units (HU). The VC percentage was calculated as the ratio between VC volume and the volume of the region of interest. For the analysis, patients were divided into 3 groups according to VC percentage, from lowest to highest: group 1 (G1) included the first quartile of VCs, group 2 (G2) included the second and third quartiles, and group 3 (G3) included the fourth quartile. Risk of in-stent thrombosis was analysed using a multivariate model. RESULTS: Thirty-nine patients were included (10 in G1, 19 in G2, and 10 in G3), and mean follow-up duration was 24 ± 14.6 months. Patients in G1 and G3 had, respectively, a VC rate of <1% (no VC) and >20% (severe VC). In G2, VC was considered to be intermediate. There was no statistical difference in the cardiovascular risk factors and preoperative medication. A significant difference was found for the healthy FP diameter between G1 (4.6 ± 0.8 mm) and G3 (6.8 ± 0.8 mm, P < 0.0001) and between G2 (5.2 ± 1 mm) and G3 (P < 0.0001). The rate of drug-eluting stents was similar in all groups. There was no difference between groups concerning the rate of in-stent restenosis, target lesion revascularization, and target extremity revascularization. There was a higher rate of in-stent thrombosis for G1 versus G2 (P = 0.037), and no difference was noted between G1 versus G3 (P = 0.86) or G2 versus G3 (P = 0.12). G3 was associated with early stent thrombosis (<1 month), while G1 was associated with late stent thrombosis (6-24 months). On multivariate analysis, only one predictive factor for stent thrombosis was found: patients with intermediate VC seemed to be protected against in-stent thrombosis (odds ratio = 0.27, 95% confidence interval: 0.1-0.77; P = 0.014). CONCLUSIONS: The study showed that VC quantification with CT imaging is feasible and useful for comparing outcomes following PAD endovascular revascularization. Below a certain threshold, the presence of VC might be necessary for plaque stability and may protect against in-stent thrombosis.

Elective frozen elephant trunk procedure using the E-Vita Open Plus prosthesis in 94 patients: a multicentre French registry.

OBJECTIVES: Our goal was to evaluate the operative outcomes of the frozen elephant trunk technique using the E-Vita Open Plus® hybrid prosthesis in chronic aortic arch diseases and report clinical and radiological outcomes at the 1-year follow-up. METHODS: As determined from a prospective multicentre registry, 94 patients underwent frozen elephant trunk procedures using the E-Vita Open Plus hybrid device for the treatment of chronic aortic conditions, including 50% chronic aortic dissections, 40% degenerative aneurysms and 10% miscellaneous indications. Fifty percent of the cases were reoperations. RESULTS: The perioperative mortality rate was 11.7%. Spinal cord ischaemia and stroke rates were 4% and 9.6%, respectively. The mean cardiopulmonary bypass time was 252 ± 97 min, cardiac ischaemia time was 152 ± 53 min and cerebral perfusion time was 82 ± 22 min. Concomitant procedures were observed in 15% of patients. Among the 83 surviving patients, the survival rate after the 1-year follow-up was 98%. Eleven percent of patients underwent endovascular completion, whereas 4% of patients required aortic reintervention at 1 year. CONCLUSIONS: The E-Vita Open Plus hybrid device confirms the favourable short- and mid-term outcomes offered by its predecessor in frozen elephant trunk procedures in patients with chronic aortic arch disease. Implantation of the E-Vita Open Plus is associated with good 1-year survival rates, good rates of favourable aortic remodelling in both chronic dissection and degenerative aneurysms and a reproducible technique in a multicentre registry. Continued follow-up is required due to the risk of evolution at the downstream aorta.

Endovascular Treatment of Asymptomatic Abdominal Aortic Aneurysms in Octogenarians: Factors Influencing Long-term Survival.

BACKGROUND: Beyond the age of 80 years, the preventive treatment of an asymptomatic abdominal aortic aneurysm (AAA) has to be decided in light of the life expectancy which it is difficult to evaluate, but it is important to determine who in this population will benefit from it. The objective of our study was to determine the factors influencing short-term mortality and long-term survival in patients aged 80 years and older after the endovascular treatment of AAAs (EVAR). MATERIAL AND METHODS: We present a retrospective analysis of the prospective databases of 4 French academic departments of vascular surgery, bringing together the data of all the patients presenting an AAA who were treated by EVAR between 1998 and 2011. Logistic regression and multivariate analysis with a Cox survival model were used to determine the factors influencing perioperative and long-term mortality. The cumulative rate of events for the measurement of survival was calculated with the technique of Kaplan-Meier. RESULTS: We treated 345 octogenarians and 339 younger patients. The average follow-up was 40 months. Average survival was 75% at 36 months and 49% at 60 months. There was no evidence of any risk factor influencing mortality at 30 days in the octogenarians. However, chronic kidney disease (odds ratio [OR] = 3.95, P <0.001) and chronic respiratory failure (OR = 2.62, P <0.001) proved to be independent factors of a poor long-term prognosis. CONCLUSIONS: The treatment by stent graft in octogenarians is effective in the long term. The presence of an impaired renal function or respiratory failure in this population could put into question the operative indication.

Generic thrombus segmentation from pre- and post-operative CTA.

PURPOSE: Abdominal aortic aneurysm (AAA) is a localized, permanent and irreversible enlargement of the artery, with the formation of thrombus into the inner wall of the aneurysm. A precise patient-specific segmentation of the thrombus is useful for both the pre-operative planning to estimate the rupture risk, and for post-operative assessment to monitor the disease evolution. This paper presents a generic approach for 3D segmentation of thrombus from patients suffering from AAA using computed tomography angiography (CTA) scans. METHODS: A fast and versatile thrombus segmentation approach has been developed. It is composed of initial centerline detection and aorta lumen segmentation, an optimized pre-processing stage and the use of a 3D deformable model. The approach has been designed to be very generic and requires minimal user interaction. The proposed method was tested on different datasets with 145 patients overall, including pre- and post-operative CTAs, abdominal aorta and iliac artery sections, different calcification degrees, aneurysm sizes and contrast enhancement qualities. RESULTS: The thrombus segmentation approach showed very accurate results with respect to manual delineations for all datasets ([Formula: see text] and [Formula: see text] for abdominal aorta sections on pre-operative CTA, iliac artery sections on pre-operative CTAs and aorta sections on post-operative CTA, respectively). Experiments on the different patient and image conditions showed that the method was highly versatile, with no significant differences in term of precision. Comparison with the level-set algorithm also demonstrated the superiority of the 3D deformable model. Average processing time was [Formula: see text]. CONCLUSION: We presented a near-automatic and generic thrombus segmentation algorithm applicable to a large variability of patient and imaging conditions. When integrated in an endovascular planning system, our segmentation algorithm shows its compatibility with clinical routine and could be used for pre-operative planning and post-operative assessment of endovascular procedures.