Bridging Stent Graft Research Articles

Use of Bilateral Cook Zenith Iliac Branch Devices to Preserve Internal Iliac Artery Flow During Endovascular Aneurysm Repair

Iliac branch devices (IBD) have become a widespread option to preserve antegrade internal iliac artery (IIA) flow during endovascular aneurysm repair (EVAR). Reported experience with bilateral implantation of IBDs is limited. This study aimed to describe the indications, technical options, and outcomes with the use of bilateral IBDs. All patients undergoing elective implantation of bilateral Cook Zenith IBD between January 2010 and September 2017 in a single centre were included. Bilateral IBD was indicated in physically active, anatomically suitable patients and those with previous or concomitant surgery for a thoraco-abdominal aortic aneurysm or impaired collateral circulation to the IIA. Data were collected prospectively. Twenty-nine patients (29 male, mean age 64.1±10 years) were included. Of the 58 IBDs, 48 (83%) were implanted in one procedure and 10 (17%) in two procedures (mean time between procedures 30.4±9 months). Nineteen patients (65%) had a previous or simultaneous EVAR and the remaining 10 (35%) a previous or simultaneous complex aortic repair. Mean CIA diameter was 35.2±8mm. Technical success was achieved in 55 of the 58 IBDs (95%) with no mortality. Axillary artery access was used in 13 (38%) procedures. During follow up, four (7%) IIA branches occluded (1 bilateral occlusion and 2 unilateral). Estimated IIA branch patency at one and three years was 97.8%±2% and 88.5%±7%, respectively. All patients with late IIA occlusion remained asymptomatic. Re-intervention was needed in four patients (14%): two bridging stent graft extensions for type Ib endoleak, one relining of the external iliac artery because of mural in-stent thrombus and one femoro-femoral crossover bypass to treat an external iliac limb occlusion. Bilateral implantation of IBDs is a safe and effective technique to preserve IIA flow in selected patients with suitable anatomy, showing similar technical success and mid-term outcomes to the unilateral use of the device.

Technical Note: Dissection Flap Perforation with Use of a TIPS-Needle During Fenestrated Endografting for Post-dissection Thoracoabdominal Aneurysms.

Fenestrated/branched thoracic endovascular aneurysm repair (F/Br-TEVAR) is a new minimal invasive treatment option for patients with post-dissection thoracoabdominal aortic aneurysms. This specific pathology is challenging to F/Br-TEVAR, especially when target vessels originate from the false lumen. Crossing from the true lumen into the false lumen to catheterize such target vessels may prove cumbersome in the usually thickened dissection flap. We describe a bailout technique when standard catheterization techniques fail, by using a transjugular intrahepatic portosystemic shunt (TIPS)-needle to perforate the dissection flap. The fenestration is subsequently dilated using balloon angioplasty to allow for insertion and deployment of the bridging stent graft. When other catheterization techniques fail in vessel originating from the false lumen, TIPS-needle perforation of the dissection flap is a useful bailout tool.

One Year Outcomes of 101 BeGraft Stent Grafts used as Bridging Stents in Fenestrated Endovascular Repairs

To evaluate the outcomes of the second generation BeGraft balloon expandable covered stent Graft System (Bentley InnoMed, Hechingen, Germany) implanted as bridging stent grafts during fenestrated endovascular aortic repair (FEVAR) of complex aneurysms. This was a single centre prospective study including all consecutive patients treated by FEVAR performed with second generation BeGraft stent grafts as bridging stents. Demographics of patients, diameter and length of the bridging stent grafts, technical success, re-interventions, occlusions, post-operative events, and imaging (Cone Beam CT and/or CT scan, and contrast enhanced ultrasound) were prospectively collected in an electronic database. Duplex ultrasound was performed before discharge and at 6 month follow-up. At 1 year, patients were evaluated clinically and by imaging (CT and ultrasound). Between November 2015 and September 2016, 39 consecutive patients (one woman) were treated with custom made fenestrated endografts (2-5 fenestrations) for complex aneurysms or type 1 endoleak after EVAR, using a variety of bridging stents including the BeGraft. All 101 BeGraft stent grafts were successfully delivered and deployed. There was no in hospital mortality. Early fenestration patency rate was 99% (96/97); the sole target vessel post-operative occlusion was secondary to a dissection of the renal artery distal to the stent. Complementary stenting was unsuccessful in recovering renal artery patency; bilateral renal stent occlusion was observed in the same patient on a CT scan performed 2 months after the procedure. He required post-operative dialysis. No additional renal impairment was observed. During follow-up (median 13 months [11-15]), all fenestrations stented with BeGraft stent grafts remained patent (95/97, 98%). One type 1b endoleak was detected and treated (2.6%). BeGraft stent grafts used as bridging stents during FEVAR are associated with favourable outcomes at 1 year follow-up. Long-term follow-up is required to confirm these promising results.

3:00 PM Abstract No. 386 Viabahn VBX as a novel bridging stent graft (BSG) for fenestrated and branched endovascular abdominal aortic aneurysm repair (FB-EVAR)

3:00 PM Abstract No. 386 Viabahn VBX as a novel bridging stent graft (BSG) for fenestrated and branched endovascular abdominal aortic aneurysm repair (FB-EVAR)

Abstract No. 444 Endovascular revascularization of acutely thrombosed renal fenestration bridging stent grafts: initial experience

Abstract No. 444 Endovascular revascularization of acutely thrombosed renal fenestration bridging stent grafts: initial experience

Up-and-Over Technique for Implantation of Iliac Branch Devices After Prior Aortic Endograft Repair

Purpose: To describe a modified up-and-over access technique for treatment of iliac artery aneurysms in patients with prior bifurcated stent-grafts for endovascular aneurysm repair (EVAR). Technique: This technique uses a coaxial 12-F flexible sheath that is docked with a through-and-through wire into a 7-F sheath advanced from the contralateral femoral approach. This maneuver allows both sheaths to be moved as a unit while maintaining position of the apex of the system as it loops over the flow divider, avoiding damage to or displacing the extant endograft. Once the 12-F sheath is positioned in the iliac limb of the aortic stent-graft and secured in place with the through-and-through wire, the repair is extended into the internal iliac artery using a bridging stent-graft or covered stent introduced via a coaxial sheath. Conclusion: The up-and-over technique with a flexible 12-F sheath mated with a 7-F sheath from the opposite side allows bilateral femoral access to be used for iliac branch device placement after prior aortic endograft procedures that create a higher, acutely angled bifurcation. Use of a through-and-through wire and a coaxial sheath for stent delivery creates a very stable platform for intervention.

Femoro-Supragenicular Popliteal Bypass with a Bridging Stent Graft in a Diffusely Diseased Distal Target Popliteal Artery: Alternative to Below-Knee Popliteal Polytetrafluoroethylene Bypass.

BackgroundLesions in distal target arteries hinder surgical bypass procedures in patients with peripheral arterial occlusive disease.MethodsBetween April 2012 and October 2015, 16 patients (18 limbs) with lifestyle-limiting claudication (n=12) or chronic critical limb ischemia (n=6) underwent femoral–above-knee (AK) polytetrafluoroethylene (PTFE) bypass grafts with a bridging stent graft placement between the distal target popliteal artery and the PTFE graft. Ring-supported PTFE grafts were used in all patients with no available vein for graft material. Follow-up evaluations assessed clinical symptoms, the ankle-brachial index, ultrasonographic imaging and/or computed tomography angiography, the primary patency rate, and complications.ResultsAll procedures were successful. The mean follow-up was 12.6 months (range, 11 to 14 months), and there were no major complications. The median baseline ankle-brachial index of 0.4 (range, 0.2 to 0.55) significantly increased to 0.8 (range, 0.5 to 1.0) at 12 months (p<0.01). The primary patency rate at 12 months was 83.3%. The presenting symptoms resolved within 2 weeks.ConclusionIn AK bypasses with a diffusely diseased distal target popliteal artery or when below-knee (BK) bypass surgery is impossible, this procedure could be clinically effective and safe when used as an alternative to femoral-BK bypass surgery.

Adapting to a total endovascular approach for complex aortic aneurysm repair: Outcomes after fenestrated and branched endovascular aortic repair

ObjectiveThis study reports the feasibility of adopting a total endovascular approach for the treatment of complex abdominal aortic aneurysms (AAAs) at a European aortic center and compares the short- and midterm results against those from large and multicenter studies. MethodsAll patients treated endovascular aortic repair (EVAR) for juxta/pararenal AAAs or thoracoabdominal aortic aneurysms (TAAAs), both elective and acute, as well as reoperations, from 2010 to 2015 were included. Treatment was fenestrated (FEVAR) or branched (BEVAR), and outcomes were analyzed for technical success and mortality at 30 and 90 days and by Kaplan-Meier curve estimates at 3 years. Outcomes on target vessels were reported as freedom from branch instability in the follow-up period. Reinterventions, endoleaks and perioperative and postoperative morbidities were analyzed. ResultsA total of 71 patients were treated for juxta/pararenal AAA (n = 40) or TAAA (n = 31): 14 type II, 4 type III, and 13 type IV. There were 47 FEVAR (including 2 physician-modified fenestrated grafts) and 24 BEVAR procedures performed. Four TAAAs were ruptured. No open repairs were performed for these pathologies in this period. Mortality was 2.8% (n = 2) at 30 days and 9.9% at 90 days (n = 7). One late rupture occurred in a patient whose treatment was a technical failure. Survival at 3 years was 77.9% ± 5.6% overall, 90.9% ± 5.2% for juxta/pararenal AAAs, and 60.7% ± 10.3% for TAAAs. Graft deployment was successful in 69 of 71 patients. Revascularization was successful in 205 of 208 target vessels (98.6%): 51 of 51 superior mesenteric arteries, 27 of 27 celiac arteries, and 127 of 130 renal arteries. There were 131 fenestrated bridging stent grafts and 74 branched bridging stent grafts. Technical success was 68 of 71 (95.7%). There were nine cases of branch instability (5 BEVARs, 4 FEVARs) in five patients (7.0%). Seven vessels (5 renal arteries and 2 superior mesenteric arteries) underwent reintervention: 5 for stenoses, 1 for occlusion, and 1 for stent migration. Freedom from branch instability at 3 years was 92.7% ± 2.5% overall, 88.6% ± 6.4% for BEVAR, and 94.6% for FEVAR. ConclusionsThe short- and midterm results obtained here indicate that the benefits of a total endovascular treatment for complex aortic aneurysms, as demonstrated by large and multicenter studies, can be adapted and replicated at other centers with a dedicated aortic service. This may help guide future considerations of how to refer or treat this complex patient group.

Initial Experience With the 6-F and 8-F Indigo Thrombectomy System for Acute Renovisceral Occlusive Events

Purpose: To examine the safety and effectiveness of the new large-bore Indigo thrombectomy catheters to treat patients with acute renovisceral occlusion without the need of thrombolytic agents. Methods: Between November 2015 and 2016, 7 consecutive patients (mean age 65±5 years; 5 men) with acute renovisceral artery occlusion were treated with the new large-bore (6-F and 8-F) vacuum-assisted thrombectomy catheters. The occluded vessels were 6 renal arteries and 3 superior mesenteric arteries (SMAs); 5 of the 9 thromboses were in bridging stent-grafts associated with branched endografts. Mean lesion length was 63±36 mm. For the SMA and all bridging stent-grafts, 8-F catheters are routinely used through a brachial access, whereas 6-F aspiration catheters were used in native renal arteries. Technical success was defined as restoration of antegrade blood flow without the need of lysis or alternative thrombectomy/revascularization strategies. Safety endpoints were any in-hospital major adverse events. Pre- and postoperative hemoglobin and hematocrit levels were compared. Results: Technical success was 100% with no major adverse events or fatal bleeding. The mean amount of aspirated blood was 219±97 mL. The mean hemoglobin and hematocrit values were 13.1±2.1 g/dL and 39%±6% prior to and 11.6±2.2 g/dL (p=0.001) and 34%±6% (p<0.0001) directly after the intervention, respectively. Conclusion: The first assessment of the new large-bore Indigo thrombectomy catheters showed them to be an effective and safe lysis-free frontline therapy for acute renovisceral artery occlusion in a small cohort of patients. New users should be fully aware of the potential blood loss during aspiration.

Endovascular repair of thoracoabdominal aortic aneurysm using the off-the-shelf multibranched t-Branch stent graft

Endovascular repair has been increasingly used to treat thoracoabdominal aortic aneurysms using patient-specific or off-the-shelf fenestrated and branched stent grafts. Device customization limits the application of patient-specific devices in patients who need urgent or emergency repair because of ruptured or large, rapidly expanding aneurysms. For these patients, an off-the-shelf multibranched stent graft, the t-Branch stent graft (Cook Medical, Bjaeverskov, Denmark) hasbeen developed based on the relative predictability of visceral vessel anatomy, allowing incorporation and intraoperative customization of target vessels with four down-going directional branches. We used the t-Branch stent graft in a 66-year-old woman with a rapidly enlarging type III thoracoabdominal aortic aneurysm. Completion angiography and follow-up computed tomography angiography demonstrated successful exclusion of the aneurysm sac, patent target vessels, and nearly complete sac shrinkage at the 12-month follow-up.

Performance of Bridging Stent Grafts in Fenestrated and Branched Aortic Endografting

Bridging stent grafts (BSGs) are used to connect the target vessel with the main body during fenestrated or branched aortic endografting (f/bEVAR). No dedicated devices are available for BSG. The aims of this study were to assess the performance of BSGs. Between January 2004 and May 2014 the data of patients treated with f/bEVAR were prospectively collected. Only patients treated after January 2010 were included. The main measurement outcome was any BSG related complications. A logistic regression analysis, including target vessel type, type of joint (fenestration or cuff), and type of BSG identified potential risk factors. One hundred and fifty consecutive patients underwent f/bEVAR, and 523 target vessels were involved. These included 104 celiac, 140 superior mesenteric, 275 renal, and four other arteries. The technical success rate was 99% (520/523 target vessels). Balloon expandable BSGs were mainly used (n = 494; 95%), and in 336 (65%) relining stents were combined. The primary reasons for technical failure were the dislocation of the main body (n = 1) and unsuccessful cannulation (n = 2). One was revascularized by means of the periscope technique. Four target vessel injuries were recorded and four renal arteries occluded peri-operatively. After a median follow up of 14 months (interquartile range 5.5-23.0), 13 (2%) BSGs occluded and 19 (4%) required re-interventions. Two SMA occlusions occurred, leading to death in both patients. The patency and freedom from re-intervention rates at 3 years amounted to 85% and 91%, respectively. Use of a branched main body was the only independent risk factor for re-intervention and for the composite event (hazard ratio [HR] 3.5, 95% confidence interval [CI] 1.3-9.9 [P = .02]; and HR 2.8, 95% CI 1.2-7.0 [P < .01], respectively). Of note, the use of relining stents seemed not to prevent BSG related complications. The currently used BSGs had low occlusion and re-intervention rates. Modifications of the branched design or dedicated BSG devices may improve outcome, especially after bEVAR.

Implantation of an Iliac Branch Device After EVAR via a Femoral Approach Using a Steerable Sheath

Purpose: To describe a contralateral femoral approach for iliac branch device implantation using a steerable sheath in the setting of an existing bifurcated stent-graft. Technique: The method is demonstrated in an 80-year-old man who developed a 4-cm iliac aneurysm 3 years after implantation of an Endurant bifurcated stent-graft. Both femoral arteries were cannulated after surgical cutdown. The steerable sheath was advanced from the contralateral side over the neobifurcation of the bifurcated stent-graft. A 0.014-inch Roadrunner wire was used as a through-and-through wire to stabilize the curve of the sheath and to get proper push. The bridging stent-graft for the iliac branch was advanced over this sheath to seal the iliac aneurysm. During the entire procedure, the sheath was stable over the neobifurcation without pulling it down. Conclusion: The contralateral femoral approach for iliac branch graft implantation is feasible in cases with an extant bifurcated stent-graft using a steerable sheath and a through-and-through wire.

Description of a new technique for repairing chronic type B dissections that involve visceral branches being fed by both true and false lumen by using both lumens as conduits

Here we present three cases performed using a novel technique where aortic flow is compartmentalized proximal to the target vessels through a physician-modified endograft. The visceral segment is then further compartmentalized by the use of another physician modified endograft. By compartmentalizing the flow proximal to the visceral segment, both the true lumen and false lumen can be used as conduits for coextensive bridging stent grafts. Overall, patients have tolerated this procedure extremely well, and while further study and follow-up must be conducted, this procedure could offer a reasonable long-term solution to thoracoabdominal aortic aneurysms complicated by dissection.

Performance of Bridging Stent Grafts in Fenestrated and Branched Aortic Endografting

Bridging stent grafts (BSGs) are used to connect the target vessel with the main body during fenestrated or branched aortic endografting (f/bEVAR). No dedicated devices are available for BSG. The aims of this study were to assess the performance of BSGs. Between January 2004 and May 2014 the data of patients treated with f/bEVAR were prospectively collected. Only patients treated after January 2010 were included. The main measurement outcome was any BSG related complications. A logistic regression analysis, including target vessel type, type of joint (fenestration or cuff), and type of BSG identified potential risk factors. One hundred and fifty consecutive patients underwent f/bEVAR, and 523 target vessels were involved. These included 104 celiac, 140 superior mesenteric, 275 renal, and four other arteries. The technical success rate was 99% (520/523 target vessels). Balloon expandable BSGs were mainly used (n = 494; 95%), and in 336 (65%) relining stents were combined. The primary reasons for technical failure were the dislocation of the main body (n = 1) and unsuccessful cannulation (n = 2). One was revascularized by means of the periscope technique. Four target vessel injuries were recorded and four renal arteries occluded peri-operatively. After a median follow up of 14 months (interquartile range 5.5-23.0), 13 (2%) BSGs occluded and 19 (4%) required re-interventions. Two SMA occlusions occurred, leading to death in both patients. The patency and freedom from re-intervention rates at 3 years amounted to 85% and 91%, respectively. Use of a branched main body was the only independent risk factor for re-intervention and for the composite event (hazard ratio [HR] 3.5, 95% confidence interval [CI] 1.3-9.9 [p = .02]; and HR 2.8, 95% CI 1.2-7.0 [p < .01], respectively). Of note, the use of relining stents seemed not to prevent BSG related complications. The currently used BSGs had low occlusion and re-intervention rates. Modifications of the branched design or dedicated BSG devices may improve outcome, especially after bEVAR.

Performance of Bridging Stent-grafts in Fenestrated and Branched Aortic Endografting

Introduction: Bridging stent-grafts (BSGs) are used to connect the target vessel with the main body during fenestrated or branched aortic endografting (f/bEVAR). At present, no dedicated device is available as BSG and different combinations of stent-grafts and relining stents have been proposed. Aims of this study were to assess the performance of the BSGs and to address potential risk factors for poor outcomes. Methods: Between 01/2010 and 03/2014, 150 consecutive patients underwent f/bEVAR and 515 target vessels were revascularized. Main measure outcome was any BSG-related complication. A logistic regression analysis including target vessel type, type of endografting (fenestrated or branched) and type of BSG identified potential risk factors for the main measure outcome. Results: The main body consisted of only fenestrations in 72 patients (48%), only branches in 68 patients (45%) and a combination of both in 10 patients (7%). Fenestrated devices were implanted mainly by Crawford type 4 and juxtarenal aneurysms (n = 57, p < 0.001). The target vessels included 104 celiac-, 139 superior mesenteric-, 268 renal- and 3 other arteries. The technical success amounted to 99.6% (511 out of 515 target vessels). Balloon expandable BSG were mainly used (n 490, 95.7%) and in 329 was relining stent combined (64.4%). Main reasons for technical failure were the dislocation of the main body (n = 2) and unsuccessful cannulation (n = 2). One could be revascularized by means of the periscope technique. Three renal arteries in two patients (0.5%) occluded perioperatively. After a mean follow-up of 11 months (range 1–41), 5 other renal artery occlusions (0.9%) occurred and 17 BSG-reinterventions (3%) were performed (Figure: residual distal type 1 endoleak celiac artery after renal extension). No SMA occlusion was reported. The patency and freedom-from-reintervention rate at 2 years amounted to 97% and 93% respectively. Revascularization of the renal artery and use of a branched main body were the only independent risk factors for occlusion (odds ratio: 11.7; 95% CI: 1.4–91.9 P = 0.03 and 3.4; 95% CI: 0.9–13.3 P = 0.03, respectively). The branched main body was also risk factor for reintervention (odds ratio 4.0; 95% CI: 1.2–13.4 P = 0.002). Of note, use of relining stents seems not to prevent BSG-related complications. Conclusion: The currently used BSGs are showed low occlusion and reintervention rates. Outcomes after bEVAR and revascularization of the renal arteries might be improved by means of a dedicated device. SMA-related complications are rare or probably underestimated due to the associated mortality.

Technical Considerations and Performance of Bridging Stent-Grafts for Iliac Side Branched Devices Based on a Pooled Analysis of Single-Center Experiences

To report a pooled analysis of single-center experiences designed to determine the performance of self-expanding vs. balloon-expandable bridging stent-grafts used in iliac branch devices (IBDs) for the repair of iliac artery aneurysms. The English-language literature in the MEDLINE and EMBASE databases was searched for articles published between 2006 and 1 March 2012 on the performance of bridging stent-grafts in the internal iliac artery. Studies were eligible for the analysis if they contained the type of bridging stent-grafts used and the time and cause of any occlusion of the bridging devices. Eight of the 13 studies published between 2006 and 2011 fulfilled the eligibility criteria. The outcome measure was the patency of bridging stent-grafts defined as absence of occlusion of the side branch in the internal iliac artery. Additionally, the performance of the self-expanding stent-grafts vs. balloon-expandable stent-grafts used in conjunction with the IBDs was compared. In the 8 studies, 100 (42%) self-expanding stent-grafts and 136 (58%) balloon-expandable stent-grafts were placed in 185 patients. Of these 236 bridging stent-grafts, 15 (6%) occluded in 13 (7%) patients: 10 within 30 days after the intervention [2 (1.5%) balloon-expandable and 8 (8%) self-expanding stent-grafts] and 5 beyond 30 days [2 (1.5%) balloon-expandable and 3 (3%) self-expanding stent-grafts]. Symptomatic presentation (hip and/or buttock claudication) of the occluded iliac branch was recorded in 7 of the 13 patients. The current literature does not support robust conclusions about the performance of bridging endografts of IBDs due to the heterogeneity of the studies. However, the occlusion rate of the bridging stent-grafts was low, especially for balloon-expandable stent-grafts compared to self-expanding devices.

Wire-loop technique to implant an iliac branched device in a patient with previous surgery for ruptured abdominal aortic aneurysm

We described a modified technique for implanting a bridging stent-graft into an iliac branched device. A 79-year-old male who had received aortobiiliac synthetic graft surgery for a ruptured abdominal aortic aneurysm six months earlier was admitted to our unit for treatment of a left common iliac aneurysm involving the origin of the hypogastric artery. A standard technique was unsuccessful at implanting the bridging stent-graft, and therefore a wire-loop guidewire over the graft bifurcation was used to stabilize the contralateral sheaths and to complete the implantation.

Bericht über die ersten 50 endovaskulären thorako-abdominellen Behandlungen mit Seitenarmprothesen

Developments with fenestrated and branched stent grafts have opened the way to treat complex aortic aneurysms involving the visceral arteries. First reports on endovascular treatment of thoracoabdominal aneurysms have demonstrated the feasibility of the technique. A literature review and results of first 50 patients treated with a custom-made Zenith device with fixed branches are presented. Most of the patients were refused open surgery mainly for the extent of the disease combined with co-morbidity, which included in most patients a combination of several risk factors. Mean aneurysm size was 71 mm and extent of the aneurysm was type I (n = 9), type II (n = 13), type III (n = 19), and type IV (n = 9), respectively. Primary and primary assisted technical successes in our series were 88 % (44 / 50) and 92 % (46 / 50), respectively. One patient died on day 1 from an intraoperative aneurysm rupture. In two patients a renal artery was lost, one due to rupture and one due to malpositioning of the bridging stent graft. In a fourth patient, a celiac artery could not be catheterised and was lost. Finally, in two more patients, catheterisation of in total three renal arteries proved impossible. This was solved by a retrograde approach for two renal arteries via laparotomy in one patient, and a spleno-renal bypass in the other patient. Thirty-day mortality was 8 %. Estimated survival at 6 months, 1 year, and 2 years was 91.2 %, 79.8 %, and 69.7 %, respectively. Freedom of reintervention of all kinds at 1 and 2 years was 81.9 % and 73.7 %, respectively. Results of fully endovascular repair of thoracoabdominal aneurysms in a high-risk cohort are promising. A learning curve should be expected. Although longer term results need to be awaited, it is likely that endovascular repair of thoracoabdominal aneurysms will become a preferential treatment option for many patients in the future.

Bridging Stent-Graft Pullout Force Analysis

To assess the pullout force (POF) of bridging stent-grafts used in thoracoabdominal stent-grafts and iliac bifurcated grafts. In an experimental setup, the POFs of Viabahn or Fluency with or without a Zilver stent were measured when deployed into the renal and celiac branches of a Zenith thoracoabdominal cuff-bearing branched stent-graft. The POFs of the Atrium i-Cast, Viabahn, Fluency, and Fluency+Zilver were measured when deployed into an iliac bifurcated graft with a short side-branch for the internal iliac artery. At least 10 trials were performed for each stent in air at room temperature. The median POF (IQR; absolute range) required to dislodge each bridging stent-graft from the 6-mm renal branch was 1.89 N (0.47 N; 1.65-2.5) for the 7-mm Viabahn, 1.17 N (0.39 N; 0.68-1.57 N) for the 7-mm Fluency, and 2.08 N (0.49 N; 1.59-2.62 N) for the 7-mm Fluency with a supporting 8-mm Zilver stent (p<0.001). For the 8-mm celiac branch, the POFs were 2.79 N (0.82 N; 2.31-4.16 N), 1.74 N (0.18 N; 1.51-1.91 N), and 2.73 N (0.94 N; 1.9-3.61 N) for the 9-mm Viabahn, 9-mm Fluency, and 9-mm Fluency with a 10-mm Zilver stent, respectively (p<0.001). For the 8-mm internal iliac branch, the POFs were 3.53 N (0.85 N; 2.55-4.72 N) for the 9-mm i-Cast, 3.82 N (0.41 N; 3.29-4.45 N) for the 9-mm Viabahn, 2.32 N (0.23 N; 1.63-2.64 N) for the 9-mm Fluency, and 2.61 N (0.71 N; 1.65-3.63 N) for the 9-mm Fluency with a 10-mm Zilver stent (p<0.001). There is a small but significant difference in pullout forces among various bridging stent-grafts. As pullout forces may be one factor contributing to type III endoleaks in complex endovascular repairs involving fenestrated and branched stent-grafts, further study is warranted to compare these grafts clinically to determine if they perform differently. According to this study, the theoretical advantages associated with the Viabahn stent-graft make it a strong choice for minimizing branch dislocations.

Abstract No. 363: Branched stent-graft repair: Which bridging stent-grafts should be used?

Abstract No. 363: Branched stent-graft repair: Which bridging stent-grafts should be used?