Fenestrated Endovascular Aortic Repair of Complex Aneurysm Using the Anaconda Fenestrated Device: 1-Year Results From the French Multicenter Registry.

PURPOSE: This study aims to assess the safety and efficacy of the fenestrated Anaconda device for the treatment of complex aortic aneurysms over 1 year in daily clinical practice. MATERIALS AND METHODS: All patients who received the graft between October 2019 and October 2020 were prospectively enrolled in an observational, multicenter national registry. The primary endpoint was the aneurysm-related 1-year mortality rate. Secondary endpoints included all-cause mortality, technical success, device-related adverse events (AEs) and major complications, secondary reinterventions, endoleaks, target vessel (TV) outcomes, and a center-volume analysis comparing mortality and secondary reintervention rate between expert centers (>15 F/BEVAR per year) and nonexpert centers (≤15 F/BEVAR per year). RESULTS: Ninety-seven patients from 28 centers were treated. Aneurysms types included juxta-renal and short neck (84.6%), pararenal (5.2%), paravisceral (3.1%), and type IV thoracoabdominal (2.5%). Configurations with 1, 2, 3, and 4 fenestrations were used in 2, 12, 18, and 65 cases, respectively, totaling 350 TVs. Technical success was 98.0%, with 1 type Ic and 1 type IIIc endoleak. Mean follow-up was 468 days. Ten patients died, with 8 deaths (8.2%) due to non-aortic causes and 2 deaths (2.1%) from unknown causes. The estimated 1-year survival rate was 92.7% (95% CI: 87.8-98.1%). The reintervention rate at 30 days was 11.3% and the estimated reintervention rate at 1 year was 21.6% (95% CI: 12.7-29.6%). No type Ia endoleak occurred during follow-up. Three type III endoleaks occurred and required reintervention. Three TV occlusion occurred, yielding a 1-year TVI-free rate of 92.4% (95% CI: 89.4-99.3). No device-related major complication was recorded, and 3 device-related AEs occurred: 1 limb migration, 1 limb kinking and 1 limb thrombosis. There was no statistically significant difference in mortality and survival without reintervention between expert and nonexpert centers (Log rank p=0.52 and p=0.16, respectively). CONCLUSION: The fenestrated Anaconda device demonstrated acceptable early and at 1-year safety and efficacy for treating primarily juxta-renal and short-neck aortic aneurysms, in centers with varying levels of experience. CLINICAL IMPACT: The Anaconda Fenestrated, as the second commercially available custom-made device for complex endovascular aortic surgery, might adress some anatomical challenges. Following market authorization, this registry presents the 1-year outcomes of real-world device usage in a large number of centers, including small clinics. The results indicate that the device provided adequate efficacy and safety for treating mostly juxta-renal and short neck aneurysms, with notable improvement in technical success rate compared to older reports.

Assessment of fenestrated Anaconda stent graft design by numerical simulation: Results of a European prospective multicenter study.

OBJECTIVE: A crucial step in designing fenestrated stent grafts for treatment of complex aortic abdominal aneurysms is the accurate positioning of the fenestrations. The deployment of a fenestrated stent graft prototype in a patient-specific rigid aortic model can be used for design verification in vitro, but is time and human resources consuming. Numerical simulation (NS) of fenestrated stent graft deployment using the finite element analysis has recently been developed; the aim of this study was to compare the accuracy of fenestration positioning by NS and in vitro. METHODS: All consecutive cases of complex aortic abdominal aneurysm treated with the Fenestrated Anaconda (Terumo Aortic) in six European centers were included in a prospective, observational study. To compare fenestration positioning, the distance from the center of the fenestration to the proximal end of the stent graft (L) and the angular distance from the 0° position (C) were measured and compared between in vitro testing (L1, C1) and NS (L2, C2). The primary hypothesis was that ΔL (|L2 - L1|) and ΔC (|C2 - C1|) would be 2.5 or less mm in more than 80% of the cases. The duration of both processes was also compared. RESULTS: Between May 2018 and January 2019, 50 patients with complex aortic abdominal aneurysms received a fenestrated stent graft with a total of 176 fenestrations. The ΔL and ΔC was 2.5 mm or less for 173 (98%) and 174 (99%) fenestrations, respectively. The NS process duration was significantly shorter than the in vitro (2.1 days [range, 1.0-5.2 days] vs 20.6 days [range, 9-82 days]; P < .001). CONCLUSIONS: Positioning of fenestrations using NS is as accurate as in vitro and could significantly decrease delivery time of fenestrated stent grafts.

Patient Specific Computer Modelling for Automated Sizing of Fenestrated Stent Grafts.

OBJECTIVE: The aim was to validate a computational patient specific model of Zenith® fenestrated device deployment in abdominal aortic aneurysms to predict fenestration positions. METHODS: This was a retrospective analysis of the accuracy of numerical simulation for fenestrated stent graft sizing. Finite element computational simulation was performed in 51 consecutive patients that underwent successful endovascular repair with Zenith® fenestrated stent grafts in two vascular surgery units with a high volume of aortic procedures. Longitudinal and rotational clock positions of fenestrations were measured on the simulated models. These measurements were compared with those obtained by (i) an independent observer on the post-operative computed tomography (CT) scan and (ii) by the stent graft manufacturer planning team on the pre-operative CT scan. (iii) Pre- and post-operative positions were also compared. Longitudinal distance and clock face discrepancies >3 mm and 15°, respectively, were considered significant. Reproducibility was assessed using Bland-Altman and linear regression analysis. RESULTS: A total of 195 target arteries were analysed. Both Bland-Altman and linear regression showed good reproducibility between the three measurement techniques performed. The median absolute difference between the simulation and post-operative CT scan was 1.0 ± 1.1 mm for longitudinal distance measurements and 6.9 ± 6.1° for clock positions. The median absolute difference between the planning centre and post-operative CT scan was 0.8 ± 0.8 mm for longitudinal distance measurements and 5.1 ± 5.0° for clock positions. Finally, the median absolute difference between the simulation and the planning centre was 0.96 ± 0.97 mm for longitudinal distance measurements and 4.8 ± 3.6° for clock positions. CONCLUSION: The numerical model of deployed fenestrated stent grafts is accurate for planning position of fenestrations. It has been validated in 51 patients, for whom fenestration locations were similar to the sizing performed by physicians and the planning centre.

Treatment of Complex Aortic Aneurysms Using Combination of Renal and Visceral Bypass and Fenestrated/Branched Stent Grafts.

BACKGROUND: The purpose of this study was to report our experience of treatment of aortic aneurysms using combination of renal and visceral arteries bypasses and fenestrated/branched stent graft in various complex anatomical situations. METHODS: Between November 2005 and March 2017, 10 patients underwent a hybrid strategy combining bypasses for renal and/or visceral arteries and custom-made fenestrated/branched stent grafts. Two patients had abdominal aortic aneurysm (1 juxtarenal and 1 suprarenal), and 8 patients had thoracoabdominal aortic aneurysm (1 type I, 2 type II including one dissection, 2 type III, 1 type IV, and 2 type V). In total, 37 renal and visceral arteries were targeted, of which 23 were treated using fenestrated or branched stent graft and 14 were treated by bypass (11 to renal artery and 3 to celiac trunk). RESULTS: Technical success was 100%, and no patient died during a mean follow-up of 24.3 ± 21 months. Six patients had 7 postoperative complications after bypass surgery, and 3 patients had 3 complications after fenestrated or branched endovascular aneurysm repair (FEVAR/BEVAR) procedure. Seven reinterventions were performed in 3 patients. No occlusion of target vessels occurred. Renal function was stable during follow-up in all patients except one who developed end-stage renal failure requiring permanent dialysis. On the last follow-up computed tomography scan, aneurysm diameter decreased for 6 patients, was stable for 3 patients, and increased for one patient, in which persistent type II endoleak was observed. Aneurysm exclusion was complete in the remaining 9 patients. CONCLUSIONS: Combination of FEVAR/BEVAR procedures with renal and/or visceral artery bypass in patients with complex aortic aneurysms is feasible with acceptable results. Morbidity associated with bypass surgery has to be carefully balanced with the risk of catheterization difficulties in the setting of adverse anatomical features of the visceral/renal arteries or the aorta.

Cryopreserved arterial allografts for in situ reconstruction of abdominal aortic native or secondary graft infection.

OBJECTIVE: The objective of this study was to evaluate the early and long-term outcome of cryopreserved arterial allografts (CAAs) used for in situ reconstruction of abdominal aortic native or secondary graft infection and to identify predictors of mortality. METHODS: We retrospectively included 71 patients (mean age, 65.2 years [range, 41-84 years]; men, 91.5%) treated for abdominal aortic native or secondary graft infection (65 prosthetic graft infections; 16 of them had secondary aortoenteric fistula, 2 venous graft infections, and 4 mycotic aneurysms) by in situ reconstruction with CAA in the university hospitals of Clermont-Ferrand and Saint-Etienne from 2000 to 2016. The cryopreservation protocol was identical in both centers (-140°C). Early (<30 days) and late (>30 days) mortality and morbidity, reinfection, and CAA patency were assessed. Computed tomography was performed in all survivors. Survival was analyzed with the Kaplan-Meier method. Univariate analyses were performed with the log-rank test and multivariate analysis with the Cox regression model. RESULTS: Mean follow-up was 45 months (0-196 months). Early postoperative mortality rate was 16.9% (11/71). Early postoperative CAA-related mortality rate was 2.8% (2/71); both patients died of proximal anastomotic rupture on postoperative days 4 and 15. Early CAA-related reintervention rate was 5.6% (4/71); all had an anastomotic rupture, and two were lethal. Early postoperative reintervention rate was 15.5% (11/71). Intraoperative bacteriologic samples were positive in 56.3%, and 31% had a sole microorganism. Escherichia coli was more frequently identified in the secondary aortoenteric fistula and Staphylococcus epidermidis in the infected prosthesis. Late CAA-related mortality rate was 2.8%: septic shock at 2 months in one patient and proximal anastomosis rupture at 1 year in one patient. Survival at 1 year, 3 years, and 5 years was 75%, 64%, and 54%, respectively. Multivariate analysis identified type 1 diabetes (hazard ratio, 2.49; 95% confidence interval, 1.05-5.88; P = .04) and American Society of Anesthesiologists class 4 (hazard ratio, 2.65; 95% confidence interval, 1.07-6.53; P = .035) as predictors of mortality after in situ CAA reconstruction. Reinfection rate was 4% (3/71). Late CAA-related reintervention rate was 12.7% (9/71): proximal anastomotic rupture in one, CAA branch stenosis/thrombosis in five, ureteral-CAA branch fistula in one, and distal anastomosis false aneurysm in two. Primary patency at 1 year, 3 years, and 5 years was 100%, 93%, and 93%, respectively. Assisted primary patency at 1 year, 3 years, and 5 years was 100%, 96%, and 96%, respectively. No aneurysm or dilation was observed. CONCLUSIONS: The prognosis of native or secondary aortic graft infections is poor. Aortic in situ reconstruction with CAA offers acceptable early and late results. Patients with type 1 diabetes and American Society of Anesthesiologists class 4 are at higher risk of mortality.

Renovascular hypertension: results in adulthood of renal autotransplantation performed in children.

BACKGROUND: This study describes the long-term results of renal autotransplantation for renovascular hypertension performed in children who are now 21 years of age or older. METHODS: Sixteen children (4 boys, 12 girls) with a mean age of 11.2 years at the time of the procedure underwent ex-vivo surgery at the university hospital of Saint-Etienne between 1992 and 2008. Acetylsalicylic acid was used for antiplatelet therapy in the postoperative period, without routine anticoagulation. The mean follow-up period was 15 years. The clinical course of these patients was retrospectively reviewed in adulthood and the results analyzed. RESULTS: The children were treated with a mean of 2.37 drugs per patient, and the mean preoperative blood pressure of the entire patient population was 151/89 mmHg. Mean preoperative creatinine clearance was 80 ml/min/1.73 m2. There was no postoperative death. One patient experienced a thrombosis immediately after the surgery, leading to a redo surgery. In this patient diuresis was restarted, but without efficient concentration and filtration, ultimately leading the patient to have a renal transplant after 1 year. At the end of the follow-up period, eight of the 16 patients (50%) were cured and the others were improved. At the last follow-up the mean blood pressure was 127/70 mmHg, and the mean number of drugs per patient was 0.68. The mean creatinine clearance at last follow-up was 104.3 ml/min/1.73 m2. Three patients had secondary procedures, with two undergoing percutaneous angioplasty (at postoperative months 9 and 12, respectively) and one having an hepatorenal bypass at postoperative year 4. Primary patency was 12/16 (75%); primary assisted patency was 15/16 (94%); secondary patency was 16/16 (100%). CONCLUSION: This study shows that renal autotransplantation has good and stable long-term results and is an effective conservative strategy for treating renovascular hypertension in children, thus avoiding nephrectomy.

Prognostic Value of Aortoiliac Calcification Score in Kidney Transplantation Recipients.

BACKGROUND: Kidney recipients are increasingly older with arterial disease and extended arterial calcifications. In a kidney transplantation population, the prognosis value of aortic and iliac calcifications remains poorly explored. We aimed to assess the impact of pretransplantation aortoiliac vascular calcifications on patients, grafts survival, and cardiovascular events. METHODS: This retrospective study included kidney transplantation patients from 2006 to 2012 for whom we had available presurgery abdominal computed tomography results (n = 100). We designed a score to quantify aortoiliac calcifications. Primary end points were patient and graft survival. Secondary end points were renal function and cardiovascular morbidity. Predictive performances of calcification score were assessed using area under receiver-operating characteristic curves. Patients were classified in quartiles depending on global calcium score value. RESULTS: The cumulated rate of death and graft loss was 13% with no significant differences for survival between quartiles. No significant difference was observed in renal function (P = 0.4). Seventeen cardiovascular events were registered with a significant correlation between calcium score elevation and need of cardiovascular surgery during the follow-up (P = 0.01). Global calcium score had a predictive value of 74.5% (95% confidence interval 0.62-0.87) with 71% sensitivity and 73% specificity. CONCLUSIONS: Aortoiliac calcifications do not decrease patient and graft survival. High calcium score predict cardiovascular events and procedures during the follow-up.

Endovascular Repair of a Short Neck Abdominal Aortic Aneurysm with a Physician-Modified Vascutek Anaconda Stent Graft.

An 81-year-old woman was referred for the treatment of a 79-mm-diameter short neck abdominal aortic aneurysm with highly tortuous iliac arteries. She was considered at high risk for open repair and not suitable for standard endovascular repair given the short length of the proximal neck. Delay for a manufactured custom-made fenestrated stent graft was too long given the diameter of the aneurysm. A flexible stent graft was preferred because of severe iliac tortuosity. Endovascular repair was performed using a physician-modified Anaconda stent graft with 1 fenestration for the left renal artery. The technique for device modification and implantation is described. Postoperative course was uneventful and 1-year computed tomography scan showed complete exclusion of the aneurysm sac and patent left renal artery.

Renal Function after Fenestrated or Branched Endovascular Aortic Repair: The Early Impairment Predictive Factors.

BACKGROUND: The purpose of this study was to define predictive factors of early renal impairment after fenestrated or branched endovascular aortic repair (FEVAR or BEVAR) for aortic aneurysm. METHODS: Eighty-two patients underwent FEVAR or BEVAR for aortic aneurysm from January 2008 to December 2014. The primary end point was postoperative renal impairment on day 15 (D15). Renal impairment was defined as a 25% decrease in the glomerular filtration rate (GFR) and a GFR < 60 mL/min/1.73 m2 according to the Risk Injury Failure Loss and End-Stage criteria. Univariate and multivariate analyses were used to determine variables associated with early postoperative renal impairment. RESULTS: Seventy-seven of the 82 patients had a creatinine level on D15 and were included in this study, including a total of 145 target renal arteries. A preoperative GFR < 60 mL/min/1.73 m2 was present in 16 (20.8%) patients. On D15, 8 (10.4%) patients had an early postoperative renal impairment and 21 (27.3%) patients had a GFR < 60 mL/min/1.73 m2. A single patient had immediate postoperative dialysis for 10 days. "Perirenal hematoma" and "preoperative renal length under 100 mm" were significantly associated with the occurrence of the renal impairment after mutual adjustment in multivariate analysis (P < 0.001 and P = 0.01). No significant association was found between preoperative renal insufficiency combining all stages or with a GFR < 60 mL/min/1.73 m2 and early renal impairment after surgery (P = 0.096 and P = 0.263). CONCLUSION: The presence of a reduced preoperative renal length and the postoperative occurrence of a perirenal hematoma are predictive factors of renal impairment on D15 for patients treated with FEVAR or BEVAR.

Digital twin and artificial intelligence technologies for predictive planning of endovascular procedures.

Current planning of aortic and peripheral endovascular procedures is based largely on manual measurements performed from the 3-dimensional reconstruction of preoperative computed tomography scans. Assessment of device behavior inside patient anatomy is often difficult, and available tools, such as 3-dimensional-printed models, have several limitations. Digital twin (DT) technology has been used successfully in automotive and aerospace industries and applied recently to endovascular aortic aneurysm repair. Artificial intelligence allows the treatment of large amounts of data, and its use in medicine is increasing rapidly. The aim of this review was to present the current status of DTs combined with artificial intelligence for planning endovascular procedures. Patient-specific DTs of the aorta are generated from preoperative computed tomography and integrate aorta mechanical properties using finite element analysis. The same methodology is used to generate 3-dimensional models of aortic stent-grafts and simulate their deployment. Post processing of DT models is then performed to generate multiple parameters related to stent-graft oversizing and apposition. Machine learning algorithms allow parameters to be computed into a synthetic index to predict Type 1A endoleak risk. Other planning and sizing applications include custom-made fenestrated and branched stent-grafts for complex aneurysms. DT technology is also being investigated for planning peripheral endovascular procedures, such as carotid artery stenting. DT provides detailed information on endovascular device behavior. Analysis of DT-derived parameters with machine learning algorithms may improve accuracy in predicting complications, such as Type 1A endoleaks.

Computational simulation model of transcatheter edge-to-edge mitral valve repair: a proof-of-concept study.

AIMS: As transcatheter mitral valve (MV) interventions are expanding and more device types and sizes become available, a tool supporting operators in pre-procedural planning and the clinical decision-making process is highly desirable. We sought to develop a finite element computational simulation model to predict the results of transcatheter edge-to-edge repair (TEER) interventions. METHODS AND RESULTS: We prospectively enrolled patients with secondary mitral regurgitation (MR) referred for a clinically indicated TEER. The 3D trans-oesophageal echocardiograms performed at the beginning of the procedure were used to perform the simulation. On the 3D dynamic model of the MV that was first obtained, we simulated the clip implantation using the same clip type, size, number, and implantation location that was used during the intervention. The 3D model of the MV obtained after the simulation of the clip implantation was compared with the clinical results obtained at the end of the intervention. We analysed the degree and location of residual MR and the shape and area of the diastolic MV area. We performed computational simulation on five patients. Overall, the simulated models predicted well the degree and location of the residual regurgitant orifice(s) but tended to underestimate the diastolic mitral orifice area. CONCLUSION: In this proof-of-concept study, we present preliminary results on our algorithm simulating clip implantation in five patients with functional MR. We show promising results regarding the feasibility and accuracy in terms of predicting residual MR and the need to improve the estimation of the diastolic MV area.

Finite element analysis of the mechanical performances of 8 marketed aortic stent-grafts.

PURPOSE: To assess numerically the flexibility and mechanical stresses undergone by stents and fabric of currently manufactured stent-grafts. METHODS: Eight marketed stent-graft limbs (Aorfix, Anaconda, Endurant, Excluder, Talent, Zenith Flex, Zenith LP, and Zenith Spiral-Z) were modeled using finite element analysis. A numerical benchmark combining bending up to 180° and pressurization at 150 mmHg of the stent-grafts was performed. Stent-graft flexibility, assessed by the calculation of the luminal reduction rate, maximal stresses in stents, and maximal strains in fabric were assessed. RESULTS: The luminal reduction rate at 90° was <20% except for the Talent stent-graft. The rate at 180° was higher for Z-stented models (Talent, Endurant, Zenith, and Zenith LP; range 39%-78%) than spiral (Aorfix, Excluder, and Zenith Spiral-Z) or circular-stented (Anaconda) devices (range 14%-26%). At 180°, maximal stress was higher for Z-stented stent-grafts (range 370-622 MPa) than spiral or circular-stented endografts (range 177-368 MPa). At 90° and 180°, strains in fabric were low and did not differ significantly among the polyester stent-grafts (range 0.5%-7%), while the expanded polytetrafluoroethylene fabric of the Excluder stent-graft underwent higher strains (range 11%-18%). CONCLUSION: Stent design strongly influences mechanical performances of aortic stent-grafts. Spiral and circular stents provide greater flexibility, as well as lower stress values than Z-stents, and thus better durability.

Perioperative evaluation of iliac ZBIS branch devices: a French multicenter study.

BACKGROUND: The purpose of this study was to evaluate short-term results of endovascular treatment of common iliac artery (CIA) aneurysms without a distal neck by using iliac branch devices (IBDs), which enable maintenance of antegrade perfusion to the internal iliac artery (IIA). METHODS: Our investigation was done in a prospective, multicenter, nonrandomized manner. IBD were implanted to exclude CIA aneurysms with a diameter >25 mm in patients unfit for open repair. The stent grafts were designed based on preoperative angio-CT findings. A covered stent implantation between the IBD and the target IIA was performed during the same surgical procedure. Angio-CT was performed within the 30 days after the procedure. From January 2009 to April 2010, 39 patients were included in our study (38 men and 1 woman, mean age 73 years). RESULTS: The CIA aneurysm (mean diameter 32.3 mm) was isolated in 15 patients and associated with an abdominal aorta aneurysm (mean diameter 66 mm) in 24 patients. The IBD was systematically connected to a bifurcated aortobiiliac stent graft. The bifurcated stent graft was implanted during the same procedure in all patients, except for two who had a bifurcated stent graft history. Median surgery time, fluoroscopy time, and volume of contrast product were 192 (range 90-360) minutes, 32 (10-120) minutes, and 150 (60-352) mL, respectively. In 37 patients (95%), the internal iliac branch was patent at the end of the surgery. In two patients (5%), it was occluded, entailing a subischemic colic episode and buttock claudication in one of them. To treat a type I endoleak, a proximal extension partially covering a renal artery was implanted during the same surgery. A type III endoleak was diagnosed on the postoperative angio-CT. In three patients, a cross-over femorofemoral bypass was performed for an external iliac leg thrombosis (and for an internal iliac branch thrombosis in one case). In all, at 30 days, no death was reported and the success rate was 90% (three leg stenoses and a type III endoleak). CONCLUSIONS: IBD implantation to maintain an antegrade internal iliac perfusion is possible and has shown promising early success. Our results can be compared with those in the published literature. A learning curve will be needed to improve the technical success rate.

Carotid artery surgery: high-risk patients or high-risk centers?

BACKGROUND: Carotid angioplasty and stenting has been proposed as an alternative to carotid endarterectomy (CEA) in patients deemed as at high risk for this surgical procedure. To date, definitely accepted criteria to identify "high-risk" patients for CEA do not exist. Our objective was to assess the relevance of numerous supposed high-risk factors in our experience, as well as their possible effect on our early postoperative results. METHODS: A retrospective review of 1,033 consecutive CEAs performed during a 5.6-year period at a single institution was conducted (Vascular Surgery Department, St. Etienne University Hospital, France). Early results in terms of mortality and neurologic events were recorded. Univariate and multivariate analyses for early risk of stroke, myocardial infarction, and death were performed, considering the influence of age, sex, comorbidities, clinical symptoms, and anatomic features. RESULTS: The cumulative 30-day stroke and death rate was 1.2%. A total of 10 strokes occurred and resulted in three deaths. The postoperative stroke risk was significantly higher in the subgroup of patients treated for symptomatic carotid artery disease: 2,6% (P = 0,004). Univariate analysis and logistic regression did not show statistical significance for 30-day results in any of the considered variables. CONCLUSION: Patients with significant medical comorbidities, contralateral carotid occlusion, and high carotid lesions can undergo surgery without increased complications. Those parameters should not be used as exclusion criteria for CEA.

Secondary procedures after infrarenal abdominal aortic aneurysms endovascular repair with second-generation endografts.

BACKGROUND: To study the incidence, the types, and the results of secondary procedures performed after endovascular treatment of infrarenal abdominal aortic aneurysm (AAA). To compare the population of patients who underwent secondary procedure (P2) with the population of those who did not require it. MATERIAL AND METHODS: Between 1998 and 2008, this study included all the patients electively treated for AAA with stentgrafts that were still available on the market on January 1, 2009. Data were prospectively collected and retrospectively analyzed. The postoperative follow-up included at least a systematic computed tomography scan at 6, 12, 18, and 24 months and then every year. P2 were defined as any additionnal procedures performed to treat aneurysm related complications after initial stentgraft implantation. RESULTS: We studied 162 patients with a mean 40 ± 31 months' follow-up. In 32 patients (19.7%), there were 46 P2, 3 of them were surgical conversion and 1 with endovascular conversion. Thirty-nine P2 were scheduled, and seven were performed in emergency. Nine patients underwent more than one P2. P2 was indicated for type II endoleak in 17 cases, 13 of them with a diameter increase; for type I endoleak in 10 cases; for AAA rupture in 3 cases; for occlusion or stentgraft stenosis in 13 cases; and for 1 type III endoleak, 1 endotension, and 1 femoro-femoral crossover bypass infection. Two ruptures occurred in patients who had undergone P2. The immediate technical success was 89.1%. At 30 days, morbidity was 10.9%, and there was no mortality. Survival rates at 3 and 5 years were respectively 85.2% and 71.9% in patients with secondary procedure and 70.6% and 47.5% in the others (p = 0.046). CONCLUSIONS: In patients treated for AAA with second generation stentgrafts, in the long term, secondary procedure rate was 19.7%. Survival rate for patients who underwent a secondary procedure was better, which was probably related to the fact that they were younger at the time of stentgraft implantation. Large AAA diameter was a secondary-procedure risk factor.

Evaluation and Verification of Fast Computational Simulations of Stent-Graft Deployment in Endovascular Aneurysmal Repair.

Fenestrated Endovascular Aortic Repair, also known as FEVAR, is a minimally invasive procedure that allows surgeons to repair the aorta while still preserving blood flow to kidneys and other critical organs. Given the high complexity of FEVAR, there is a pressing need to develop numerical tools that can assist practitioners at the preoperative planning stage and during the intervention. The aim of the present study is to introduce and to assess an assistance solution named Fast Method for Virtual Stent-graft Deployment for computer assisted FEVAR. This solution, which relies on virtual reality, is based on a single intraoperative X-ray image. It is a hybrid method that includes the use of intraoperative images and a simplified mechanical model based on corotational beam elements. The method was verified on a phantom and validated on three clinical cases, including a case with fenestrations. More specifically, we quantified the errors induced by the different simplifications of the mechanical model, related to fabric simulation and aortic wall mechanical properties. Overall, all errors for both stent and fenestration positioning were less than 5 mm, making this method compatible with clinical expectations. More specifically, the errors related to fenestration positioning were less than 3 mm. Although requiring further validation with a higher number of test cases, our method could achieve an accuracy compatible with clinical specifications within limited calculation time, which is promising for future implementation in a clinical context.

Aneurysmal extension to the iliac bifurcation increases the risk of complications and secondary procedures after endovascular repair of abdominal aortic aneurysms.

BACKGROUND: To compare the outcome of endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) in patients with and without associated common iliac artery aneurysm (CIAA) extending to the iliac bifurcation. METHODS: Review of 157 patients who underwent endovascular aneurysm repair between 1999 and 2007. Group 1 included 133 patients with and without CIAA and suitable distal common iliac neck (type A, B, C, or D). Group 2 included 24 patients with associated CIAA extending to the iliac bifurcation (type E). Stent-grafts were Powerlink (Endologix, Irvine, CA) in 42, Zenith (Cook, Bjaeverskov, Danemark) in 55, and Talent (Medtronic, Sunnyvale, CA) in 60 patients. Forty patients had aorto-uni-iliac stent-grafts. RESULTS: No difference in overall mortality and AAA rupture was observed. AAA-related complication-free survival at 5 year was 72 +/- 5% and 41 +/- 14% in group 1 and 2, respectively (p = 0.006). Secondary intervention-free survival was 84 +/- 5% and 55 +/- 12% in group 1 and 2, respectively (p = 0.0008). Incidence of distal type 1 endoleak and stent-graft thrombosis was 17 and 8 % in group 2, 3.8 and 0.8 % in group 1, respectively (p = 0.07 and p = 0.01, respectively). CONCLUSION: AAA-related complications and secondary interventions occur more frequently in patients with type E AAA. Distal type 1 endoleak and stent-graft thrombosis are more frequent in these patients. These results warrant further development of technologies that are better adapted for treatment of CIAAs, such as branched and flexible stent-grafts.

Prehospital treatment of infrarenal ruptured abdominal aortic aneurysms: a multicentric analysis.

BACKGROUND: The aim of this study was to evaluate the quality of the current treatment of patients presenting with ruptured abdominal aortic aneurysms (RAAAs), from the first symptoms to the operating room with an analysis of preoperative mortality risk factors. METHODS: For 3 years, in four vascular surgery departments, we have collected all the consecutive cases of patients operated on for RAAA. We analyzed the initial clinical situation, the means of transportation, the time elapsed before treatment, and the mortality rate at 3 days. Sixty-six RAAAs were operated on. Mean patient age was 76 years (range, 52-93 years). RESULTS: The initial symptoms were a precisely located pain either abdominal (45.3%), lumbar (17.2%), or both (14.1%) or feeling faint (10.9%). In 22.7% of the cases, an initial hemodynamic instability was observed. In 46.8% of the cases, patients first went to a peripheral hospital before being admitted into a referral centre. In 84.5% of the cases, medical mean of transportation was used. The mean distance covered was 59.8 kilometers (range, <5 km to 213 km). The initial diagnosis was accurate in 67.3% of the cases. The mean intrahospital waiting period between the arrival at a reference center and the admission into an operating room was 127 minutes. Global mortality rate was 44.2%. The main preoperative mortality factor to be noticed was the initial hemodynamic instability (p=0.0031). Among stable patients, only two of them (5.4%) worsened during the preoperative treatment. CONCLUSION: In our study, hemodynamic instability corresponds to the main prognosis factor of mortality. In most cases, the initial stability persisted and allowed additional evaluation. However, the intrahospital waiting periods appeared to be too long. To be optimal, the adequate treatment should be specifically designed as soon as a diagnosis has been established.

Compliance of abdominal aortic aneurysms before and after stenting with tissue doppler imaging: evolution during follow-up and correlation with aneurysm diameter.

Usual imaging after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) consists of AAA diameter monitoring and endoleak detection. Among additional predictor parameters previously proposed to help clinicians in better identifying subgroups of AAA still at risk of rupture, AAA wall motion after EVAR has been studied, but its value was not clearly established. Tissue Doppler imaging (TDI) is an ultrasonographic modality which allows wall motion measurements along an arterial segment. The aim of the current study was to analyze AAA wall motion with TDI before and after EVAR and to describe its evolution in patients with more than 1 month of follow-up. Twenty-five consecutive patients undergoing EVAR between February 2005 and June 2007 gave informed consent to be prospectively investigated with the TDI system before EVAR and at each visit during follow-up. The mean (SD) follow-up was 13.7 (9.7) months. Maximum mean segmental dilation (MMSD), segmental compliance, dilation at maximum diameter, pressure strain elastic modulus (Ep), and stiffness were compared between three periods (before stenting, before discharge, and at last follow-up), and their relation with AAA diameter was analyzed. A significant decrease in AAA compliance was immediately observed after successful EVAR and remained stable during later follow-up. On the other hand, AAA diameter progressively decreased along time and was statistically lower at the last control compared to the initial value. MMSD, segmental compliance, and dilation at maximum diameter were positively related to AAA diameter. This means that the larger the AAA diameter after stenting, the higher the value for these parameters can be expected. On the contrary, percentage of AAA diameter decrease and percentage of MMSD decrease were not related after successful EVAR. There was no parallelism between loss in compliance and diameter decrease along time, and there is not a unique pattern of AAA diameter and compliance evolution after EVAR. Even if comparison between patients without and with endoleak was weak due to the small sample of the latter group (five patients with endoleak), compliance tended to be greater in case of endoleak. AAA wall motion after successful EVAR reflects complex interactions between all the components of the stented aneurysm which evolve over time, including true compliance of the aneurysm wall itself; intra-aneurysm sac pressure with possible different effects for peak, mean, and pulse pressures; remodeling of the thrombus; stiffness characteristics of the graft; and systemic pressure. Combining simultaneous MMSD records with actual intrasaccular pressure measurements in patients with and without endoleak would improve our understanding of the clinical pulsatility mechanism within AAA after EVAR.