Computed Simulation 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 preprocedural planning and the clinical decision-making process is highly desirable. We sought to develop a finite element (FE) computational simulation model to predict results of transcatheter edge-to-edge (TEER) interventions. METHODS AND RESULTS: We prospectively enrolled patients with secondary mitral regurgitation (MR) referred for a clinically indicated TEER. Three-dimensional (3D) transesophageal 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(s) type, size, number, and implantation location that was used during the intervention. The 3D model of the MV obtained after simulation of the clip implantation was compared to the clinical results obtained at the end of the intervention. We analyzed the degree and location of residual MR and the shape and area of the diastolic mitral valve area. We performed computational simulation on 5 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. CONCLUSIONS: In this proof-of-concept study, we present preliminary results on our algorithm simulating clip implantation in 5 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 mitral valve area.

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.

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.

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.

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.

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.

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.

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.

Patient-specific simulation of endovascular repair surgery with tortuous aneurysms requiring flexible stent-grafts.

The rate of post-operative complications is the main drawback of endovascular repair, a technique used to treat abdominal aortic aneurysms. Complex anatomies, featuring short aortic necks and high vessel tortuosity for instance, have been proved likely prone to these complications. In this context, practitioners could benefit, at the preoperative planning stage, from a tool able to predict the post-operative position of the stent-graft, to validate their stent-graft sizing and anticipate potential complications. In consequence, the aim of this work is to prove the ability of a numerical simulation methodology to reproduce accurately the shapes of stent-grafts, with a challenging design, deployed inside tortuous aortic aneurysms. Stent-graft module samples were scanned by X-ray microtomography and subjected to mechanical tests to generate finite-element models. Two EVAR clinical cases were numerically reproduced by simulating stent-graft models deployment inside the tortuous arterial model generated from patient pre-operative scan. In the same manner, an in vitro stent-graft deployment in a rigid polymer phantom, generated by extracting the arterial geometry from the preoperative scan of a patient, was simulated to assess the influence of biomechanical environment unknowns in the in vivo case. Results were validated by comparing stent positions on simulations and post-operative scans. In all cases, simulation predicted stents deployed locations and shapes with an accuracy of a few millimetres. The good results obtained in the in vitro case validated the ability of the methodology to simulate stent-graft deployment in very tortuous arteries and led to think proper modelling of biomechanical environment could reduce the few local discrepancies found in the in vivo case. In conclusion, this study proved that our methodology can achieve accurate simulation of stent-graft deployed shape even in tortuous patient specific aortic aneurysms and may be potentially helpful to help practitioners plan their intervention.

Robotic total endoscopic sutureless aortic valve replacement: proof of concept for a future surgical setting.

BACKGROUND: Sutureless valves have recently enabled closed chest aortic valve replacement. This paper evaluates the feasibility of a robotic telemanipulation during thoracoscopic sutureless aortic valve implantation in cadavers. METHODS: Cadavers were prepared with a five thoracosopic trocar setting, with a transthoracic clamp inserted in the first right intercostal space and the optics inserted in the second. Seven sutureless valve implantations were scheduled using 5 Sorin Perceval and 2 Medtronic 3f Enable valves. RESULTS: In all cases performance of pericardial suspension, aortotomy and root exposure required less than 20 min. Native valve excision and sutureless bioprosthesis implantation was technically feasible in all cases. A satisfactory prosthesis sealing was ascertained visually and the absence of paravalvular leakages was assessed with a nerve hook test around the prosthetic flange. CONCLUSIONS: Closed chest and robot assisted sutureless valve implantation is feasible in cadavers. Robotic technology can enhance reproducibility of the technique. Copyright © 2015 John Wiley & Sons, Ltd.

Patient-specific numerical simulation of stent-graft deployment: Validation on three clinical cases.

Endovascular repair of abdominal aortic aneurysms faces some adverse outcomes, such as kinks or endoleaks related to incomplete stent apposition, which are difficult to predict and which restrain its use although it is less invasive than open surgery. Finite element simulations could help to predict and anticipate possible complications biomechanically induced, thus enhancing practitioners' stent-graft sizing and surgery planning, and giving indications on patient eligibility to endovascular repair. The purpose of this work is therefore to develop a new numerical methodology to predict stent-graft final deployed shapes after surgery. The simulation process was applied on three clinical cases, using preoperative scans to generate patient-specific vessel models. The marketed devices deployed during the surgery, consisting of a main body and one or more iliac limbs or extensions, were modeled and their deployment inside the corresponding patient aneurysm was simulated. The numerical results were compared to the actual deployed geometry of the stent-grafts after surgery that was extracted from postoperative scans. We observed relevant matching between simulated and actual deployed stent-graft geometries, especially for proximal and distal stents outside the aneurysm sac which are particularly important for practitioners. Stent locations along the vessel centerlines in the three simulations were always within a few millimeters to actual stents locations. This good agreement between numerical results and clinical cases makes finite element simulation very promising for preoperative planning of endovascular repair.

Total endoscopic sutureless aortic valve replacement: rationale, development, perspectives.

Transcatheter valve implantation is progressively becoming the first line option for high risk patients in the management of severe aortic valve stenosis. Surgery is likely to remain the gold standard treatment option for intermediate risk patients since it ensures ablation of the underlying pathology and the calcified aortic valvular tissue, which potentially can act as a nidus of chronic embolization and provoke neurocognitive dysfunction in this subset of active patients. The surgical approach is continually evolving, with sutureless technology having the potential to facilitate ministernotomy and minithoracotomy approaches. Furthermore, Nitinol stented models can be introduced through thoracoscopic trocars, enabling the evolution of totally endoscopic aortic valve replacement (TEAVR). We present herein the development of TEAVR, starting from the cadaver experience in our lab. We transitioned through a clinical minithoracotomy video-assisted experience until we finally could initiate a program of human sutureless TEAVR. The limitations of this approach, which is still in refinement, and possible innovative solutions in order to build up a quick and reproducible procedure are discussed.

Endovascular repair of mitroaortic intervalvular fibrosa aneurysm after bentall surgery.

We report the first case of a successful transapical transcatheter treatment of a giant pseudoaneurysm originating from a rupture of the mitroaortic fibrosa that occurred 3 months after a Bentall procedure in a 81-year-old male patient. Because of the age of the patient and the location of the leak at the mitroaortic fibrosa, the risk of a conventional ascending aorta reoperation was considered too high, and a transcatheter approach was chosen. A transapical puncture was performed with a left minithoracotomy followed by a catheterization of the pseudoaneurysm neck and an 8-mm Amplatzer (St. Jude Medical, Saint Paul, MN, USA) device was delivered, resulting in a successful complete endovascular exclusion of the pseudo-aneurysmal sac.

Deployment of stent grafts in curved aneurysmal arteries: toward a predictive numerical tool.

The mechanical behavior of aortic stent grafts plays an important role in the success of endovascular surgery for aneurysms. In this study, finite element analysis was carried out to simulate the expansion of five marketed stent graft iliac limbs and to evaluate quantitatively their mechanical performances. The deployment was modeled in a simplified manner according to the following steps: (i) stent graft crimping and insertion in the delivery sheath, (ii) removal of the sheath and stent graft deployment in the aneurysm, and (iii) application of arterial pressure. In the most curved aneurysm and for some devices, a decrease of stent graft cross-sectional area up to 57% was found at the location of some kinks. Apposition defects onto the arterial wall were also clearly evidenced and quantified. Aneurysm inner curve presented significantly more apposition defects than outer curve. The feasibility of finite element analysis to simulate deployment of marketed stent grafts in curved aneurysm models was demonstrated. The study of the influence of aneurysm tortuosity on stent graft mechanical behavior shows that increasing vessel curvature leads to stent graft kinks and inadequate apposition against the arterial wall. Such simulation approach opens a very promising way toward surgical planning tools able to predict intra and/or post-operative short-term stent graft complications.

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.