Renal Stent Occlusion Research Articles

Preliminary experience with the new off-the-shelf 4 inner branches E-nside for the treatment of complex aortic disease

Abstract Objective In case of complex aortic aneurysmal disease, fenestrated or branched EVAR (b/f-EVAR) is considered as a valid and safe alternative to open surgery. However, one the main limitation is the time required for manufacture, limiting its use in emergent situations. The new off-the-shelf 4 inner branches E-nside (Jotec, Hechingen, Germany) has been developed to offer a solution in such circumstances. The aim of this study was to report our preliminary monocentric experience with this new device. Methods Retrospective analysis of prospective data retrieved from 1 center between November 2020 and January 2022 was done. Endpoints were technical success, postoperative morbidity, rate of endoleak and any aneurysm-related re-interventions during follow-up. Results In this study, 15 patients (mean age 73 years, range 59–90) were identified. There was a majority of male (9/15) and all of them but 3 were asymptomatic. The mean aneurysmal diameter was 60 mm (range 50–100). There were 3 cases of juxtarenal aortic aneurysms (20%), 1 Crawford type I (7%), 4 type II (27%), 4 type III (27%) and 3 type IV (20%) aneurysms. In 7 cases, a 2-steps procedure was done with a TEVAR first followed by Enside implantation. There was a technical success in 93% with 1 open conversion for a mesenterical bypass. There was no death in the post-operative period. During the post-operative period, 33% of patients (5/15) presented complications with 3 complications related to the femoral or iliac access and 2 cases of spinal cord ischemia (13%). One case occurred in an emergent setting of a type III aneurysm rupture. The other case was the open conversion and the patient also developed a colic ischemia and finally died 4 months alter. The mean length of stay was 9 days. During the follow-up, 2 reinterventions were necessary, 1 for a type Ic endoleak with distal prolongation of the stent and 1 renal stent occlusion treated by relining. The overall target vessel patency was 98%. Conclusion The use of the off-the-shelf 4 inner branches E-nside appears to be safe with good technical success for the treatment of complex aortic aneurysmal disease. It is associated with an acceptable rate of complications and allows for treatment of a wide variety of diseases in an emergent setting. Further patients and longer follow-up are required to better evaluate the exact role of this new device.

Patient-specific changes in aortic hemodynamics is associated with thrombotic risk after fenestrated endovascular aneurysm repair with large diameter endografts

BackgroundThe durability of fenestrated endovascular aneurysm repair (fEVAR) has been threatened by thrombotic complications. In the present study, we used patient-specific computational fluid dynamic (CFD) simulation to investigate the effect of the endograft diameter on hemodynamics after fEVAR and explore the hypothesis that diameter-dependent alterations in aortic hemodynamics can predict for thrombotic events. MethodsA single-institutional retrospective study was performed of patients who had undergone fEVAR for juxtarenal aortic aneurysms. The patients were stratified into large diameter (34-36 mm) and small diameter (24-26 mm) endograft groups. Patient-specific CFD simulations were performed using three-dimensional paravisceral aortic models created from computed tomographic images with allometrically scaled boundary conditions. Aortic time-averaged wall shear stress (TAWSS) and residence time (RT) were computed and correlated with future thrombotic complications (eg, renal stent occlusion, development of significant intraluminal graft thrombus). ResultsA total of 36 patients (14 with a small endograft and 22 with a large endograft) were included in the present study. The patients treated with large endografts had experienced a higher incidence of thrombotic complications compared with small endografts (45.5% vs 7.1%; P = .016). Large endografts were associated with a lower postoperative aortic TAWSS (1.45 ± 0.76 dynes/cm2 vs 3.16 ± 1.24 dynes/cm2; P < .001) and longer aortic RT (0.78 ± 0.30 second vs 0.34 ± 0.08 second; P < .001). In the large endograft group, a reduction >0.39 dynes/cm2 in aortic TAWSS demonstrated discriminatory power for thrombotic complications (area under the receiver operating characteristic curve, 0.77). An increased aortic RT of ≥0.05 second had similar accuracy for predicting thrombotic complications (area under the receiver operating characteristic curve, 0.78). The odds of thrombotic complications were significantly higher if patients had met the hemodynamic threshold changes in aortic TAWSS (odds ratio, 7.0; 95% confidence interval, 1.1-45.9) and RT (odds ratio, 8.0; 95% confidence interval, 1.13-56.8). ConclusionsPatient-specific CFD simulation of fEVAR in juxtarenal aortic aneurysms demonstrated significant endograft diameter-dependent differences in aortic hemodynamics. A postoperative reduction in TAWSS and an increased RT correlated with future thrombotic events after large-diameter endograft implantation. Patient-specific simulation of hemodynamics provides a novel method for thrombotic risk stratification after fEVAR.

Jotec E-Ventus BX Stent Graft Deployment in the FEVAR and Iliac Branch Device: Single Centre Experience.

Objectives: To evaluate the outcomes of the E-ventus BX balloon-expandable stent graft system (Jotec, Hechingen, Germany) implanted as bridging stent grafts during fenestrated endovascular aortic repair (FEVAR) and the iliac branch device (IBD) of complex aneurysms.Methods: This was a single centre retrospective analysis prospective study including all consecutive patients treated by FEVAR and the IBD performed with E-ventus BX stent grafts as bridging stents. Demographics of patients, the diameter and length of the bridging stent grafts, technical success, reinterventions, occlusions, post-operative events, and imaging (computed tomography [CT] scan and ultrasound) were prospectively collected in an electronic database. Follow-ups were performed with clinical assessment and a CT angiogram scan at four weeks after discharge followed by a duplex ultrasound every six months for two years and then a yearly duplex scan afterwards.Results: Between June 2015 and October 2017, 40 consecutive patients (three females) were treated with custom made fenestrated endografts and the iliac branch device for complex aneurysms, using the E-Ventus BX stent graft. All 82 E-Ventus BX stent grafts were successfully delivered and deployed. There was no in-hospital mortality. The early bridging stents patency rate was 97.6% (80 out of 82). The two-target vessel post-operative occlusion was secondary to kink of the renal stents and failure for re-lining of the renal artery. Of the two patients, only one needed permanent dialysis. On the late follow-up (after 30 days), two other patients demonstrated a renal stent occlusion, with one treated successfully with re-lining of the stent and the other patient treated conservatively. Neither of them needed permanent dialysis. A follow-up was maintained for 36 patients until April 2018 with a median follow-up of 18 months. All bridging stents E-Ventus BX stent grafts remained patent (78 out of 82, 95.1%).Conclusion: E-Ventus BX stent grafts used as bridging stents during FEVAR and the IBD are associated with favourable outcomes at the mid-term follow-up. Long-term follow-up is required to confirm these promising results.

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.

Mid-term Outcomes of Endovascular Repair of Ruptured Thoraco-abdominal Aortic Aneurysms with Off the Shelf Branched Stent Grafts

ObjectiveTo assess the mid-term outcomes and feasibility of branched endovascular repair (b-EVAR) of ruptured thoracoabdominal aortic aneurysms (rTAAAs). MethodsAll patients undergoing b-EVAR of rTAAAs between 2011 and 2016 were included. Pre-, intra and postoperative imaging was reviewed to assess technical success, outcomes, and feasibility of b-EVAR in the emergent setting. ResultsEleven emergency b-EVAR of rTAAAs (10 aneurysms and 1 chronic dissection) were performed using off-the-shelf (OTS) branched stentgrafts. Only 18% of patients complied to the anatomical instruction-for-use of the OTS device; a small aortic lumen and occluded target vessels were the main violations. Median operative time was 430 (IQR 395-629) minutes. Technical failure was 36% including one intraoperative death, one target vessel catheterization failure, one type Ia and one type III endoleak. Thirty-day mortality was 27%. Only early re-intervention was for the type Ia endoleak. Spinal cord ischemia occurred in 4 patients (30%), of which 2 recovered completely. Median clinical follow-up were 15 (IQR 7-39) months respectively. The median clinical follow-up index (FUI) was 0.65 (0.32–0.95). Overall survival was 75 ± 21.7% at 18 months. Four branch occlusions occurred; one renal stent occlusion led to permanent hemodialysis. Branch patency was 87.5 ± 8.3% and 72.2 ± 12% at 1 and 2 years, respectively. One stentgraft migrated but no late major endoleak occurred. ConclusionEmergency b-EVAR of rTAAA with OTS device is feasible despite a low anatomical suitability. With proper adjunctive procedures, it can be offered to most hemodynamically stable patients. These time-consuming complex procedures are not suitable for unstable patients. Often the procedure is done as life-saving in the emergency setting and reinterventions may be needed later. Consequently, the success rates are lower than in the elective setting. These results need to be confirmed by larger studies and longer follow-up.

Outcomes of Chimney and/or Periscope Techniques in the Endovascular Management of Complex Aortic Pathologies.

Background:The chimney/periscope technique has been used to address complex aortic pathologies. This study aimed to report the outcomes and experiences of chimney and/or periscope grafts (CPGs) used in the endovascular management of complex aortic pathologies.Methods:Twenty-two patients with complex aortic pathologies were retrospectively studied from January 2013 to August 2016 in two vascular centers of teaching hospitals. All patients were diagnosed using computed tomography angiography (CTA). The patients were followed up at postoperative 1, 3, 6, and 12 months and yearly thereafter with X-ray, ultrasound, and/or CTA.Results:Twenty-two cases (17 males; mean age 60.7 ± 16.3 years) with complex aortic pathologies were analyzed. Nineteen patients underwent CPGs only, and the other three cases underwent the simultaneous implantation of chimney/periscope and fenestrated/scallop grafts. Twenty-six arteries were managed with forty CPGs during the procedures. Complete angiographies revealed two Type I endoleaks, one Type III endoleak, and one Type IV endoleak. Other intraoperative complications included brachial thrombosis, external iliac artery rupture, and left renal stenosis. The 30-day mortality was 0. The mean follow-up was 26.1 ± 10.1 months with a range of 2–39 months. During the follow-up, two Type I endoleaks and one Type IV endoleak were observed. One right renal stent occlusion occurred in the 5th month and turned patent after reintervention. Three patients died during the follow-up, one due to an aneurysm rupture as a Type I endoleak, and two due to myocardial infarction. The instant technical success was 96%. The primary and secondary patencies were 92% and 96%, respectively. The overall survival rates were 95%, 84%, and 84% at 12, 24, and 36 months, respectively. Stent migration was not observed in any patient.Conclusions:Chimney/periscope techniques could be used to tackle complex aortic pathologies, but the indications must be strictly controlled, and additional experiences are required.

Renal Outcomes Following Fenestrated and Branched Endografting

The purpose of this study was to analyze immediate and long-term renal outcomes (renal function and renal events) after fenestrated (FEVAR) and branched endovascular aortic aneurysm repair (BEVAR). All FEVAR and BEVAR performed between October 2004 and October 2012 were included in this study. Post-operative acute renal failure (ARF) was defined according to the RIFLE criteria. Renal volume (calculated with a 3D workstation) and estimated glomerular filtration rate (GFR) (estimated with the Modification of Diet in Renal Disease [MDRD] formula) were evaluated before the procedure, before discharge, 12 months after, and yearly thereafter. Renal stent occlusion, dissection, fracture, stenosis, kink, renal stent related endoleak, and renal stent secondary intervention were all considered "renal composite events" and analyzed. A time to event analysis was performed for renal events and secondary renal interventions. 225 patients were treated with FEVAR and BEVAR. Renal target vessels (n = 427) were perfused by fenestrations (n = 374), or branches (n = 53). Median follow up was 3.1 years (2.9-3.3 years). Technical success was achieved in 95.5% of patients. Post-operative ARF was seen in 64 patients (29%). Mean total renal volume and eGFR at 1 year, 2 year, and 3 year follow up were significantly lower when compared with pre-operative levels (after BEVAR and FEVAR); the decrease at 3 years was 14.8% (6.7%; 22.2%) (p = .0006) for total renal volume and 14.3% (3.1%; 24.3%) (p = .02) for eGFR. The 30 day and 5 year freedom from renal composite event was 98.6% (95.8-99.6%) and 84.5% (76.5-89.9%) after FEVAR and BEVAR (NS). The 30 day and 5 year freedom from renal occlusion was 99.5% (96.7-99.9%) and 94.4% (89.3-97.1%) after FEVAR and BEVAR (NS). FEVAR and BEVAR are durable options for the treatment of complex aortic aneurysms and are associated with low renal morbidity, without differences between devices types. The clinical impact of decreasing renal volume over time in these patients is yet to be fully understood.

Renal Outcomes Following Fenestrated and Branched Endografting

Introduction: The purpose of this study was to analyze immediate and long-term renal outcomes (renal function and renal events) after fenestrated (FEVAR) and branched endovascular aortic aneurysm repair (BEVAR). Methods: All FEVAR and BEVAR performed between October 2004 and October 2012 were included in this study. Postoperative acute renal failure (ARF) was defined and classified according to the RIFLE criteria. Renal volume (calculated with a 3D workstation) and eGFR (estimated with the MDRD formula) were evaluated before the procedure, before discharge, 12 months after and yearly thereafter. Renal stent occlusion, dissection, fracture, stenosis, kink, renal stent related type III endoleak and renal stent secondary intervention were all considered “renal composite events” and analyzed. A time-to-event analysis was performed for renal events and renal secondary interventions. Results: During the study period, 225 patients were treated with FEVAR and BEVAR. Renal target vessels (n = 427) were perfused by fenestrations (n = 274) or branches (n = 53). Median follow-up was 2.4 years (2.2–2.6). FEVAR and BEVAR were associated with similar mean renal artery diameter and renal artery angulations. Preoperative renal stenosis rate was higher with BEVAR (p < 0.021). Technical success was achieved in 96.4% of patients. Postoperative ARF was depicted in 64 patients (29%), requiring transient hemodialysis in 12 patients (5.3%) and permanent hemodialysis in one case (0.44%). An additional 4 patients (1.9%) required hemodialysis during follow-up. Significant decrease in right renal volume (17.07 cm3; 95% confidence interval (CI), 12.52–21.67), left renal volume (24.55 cm3; 95% CI, 19.14–29.97) and eGFR (12.54 ml/min per 1.73 m2; 95% CI, 8.43–16.66) were observed during follow-up (p < 0.000). The 30-day, 1-year and 5-year freedom from renal composite event was 98.1% (95% CI, 97.2%–99%), 95% (95% CI, 93.5%–96.5%) and 87.5% (95% CI, 84.7%–90%). Freedom for renal composite events was significantly higher in FEVAR (p < 0.048) compared to BEVAR. The 30-day, 1-year and 5-year freedom from renal occlusion was 99.5% (95% CI, 99%–100%), 98.5% (95% CI, 97.6%–99.4%) and 93.8% (95% CI, 91.7%–95.9%) after FEVAR and BEVAR (NS). Median time to renal related secondary intervention was 450 days (Q1–Q3, 124–991.5) for both procedures. Conclusion: FEVAR and BEVAR are durable options for the treatment of complex aortic aneurysms and are associated with a low renal morbidity rate. Freedom from renal composite events was significantly higher with FEVAR. Renal volume is as accurate way to depict renal dysfunction during follow-up.

Visceral stent patency in fenestrated stent grafting for abdominal aortic aneurysm repair

Fenestrated endovascular abdominal aortic aneurysm repair (F-EVAR) has been introduced for treatment of aneurysms in which visceral arteries are incorporated. Patency of target vessels has been reported to be excellent. Results of the use of stent grafts to accommodate visceral arteries in F-EVAR are presented in this study, including an overview of factors that affect outcome. All patients treated with fenestrated stent grafts in a single center between November 2001 and October 2011 were reviewed. Patients treated for suprarenal, juxtarenal, and infrarenal short-necked aortic aneurysms were included. Patients with thoraco-abdominal aneurysms or aneurysms treated with grafts with fixed side branches were excluded. Polytetrafluoroethylene covered stents were used routinely since June 2005. Target vessels and stents were examined using computed tomography angiography reconstructions. Primary end points were primary patency, defined as the absence of occlusion, and loss of renal function. Secondary end points were technical success, stenosis (defined as a ≥50% angiographic diameter reduction), stent fracture, and mortality. A total of 138 patients with a median age of 73 years (range, 50-91 years) met the inclusion criteria. Median computed tomography angiography follow-up was 13 months (range, 1-97 months). In total, 392 target vessels were provided with 140 scallops and 252 fenestrations. Visceral stents (-grafts) were placed in 254 target vessels. Technical success was obtained in 249 arteries (98.0%). Overall stent patency of target vessels was 95.7% at 1 year and 88.6% at 4 years. Renal artery stent patency was 97.4% at 1 year and 91.2% at 4 years (96.8% and 89.1% for uncovered stents; 97.3% and 92.4% for covered stents, respectively). There was no significant difference in patency between covered and uncovered stents in renal arteries (P = .71). Renal artery stenosis occurred in 26 stented arteries (11.3%) and occlusion in seven arteries. Renal artery stent stenosis occurred significantly more in uncovered than in covered stents (P = .04). Stent fractures occurred more in uncovered than in covered stents (P = .01) and was associated with a significantly lower visceral stent patency rate (P < .01). During follow-up, 13 patients developed permanent renal function impairment (9.4%), of which two required permanent dialysis (1.4%). Renal dysfunction was significantly associated with renal stent occlusion or stenosis (P < .01). Patency rates of visceral artery stent (-grafts) in F-EVAR were 95.7% at 1 year and 88.6% at 4 years. Patency rates were affected by stent fractures, which occurred more in uncovered compared with covered stents. Renal artery stent stenosis occurred more in uncovered compared with covered stents. Renal dysfunction was significantly associated with renal stent occlusion or stenosis.

Outcomes of fenestrated endovascular repair of juxtarenal aortic aneurysm

To evaluate late outcomes after fenestrated endovascular aortic repair (f-EVAR) in a tertiary European referral center. In 2009, we published short- and midterm results after f-EVAR in the first 54 patients treated with this technique at our center between September 2002 and June 2007. In this paper, we provide long-term follow-up of the same patient cohort with the main focus on target vessel (TV) patency, renal function, reinterventions, and survival. A total of 54 patients were included in this study. Median age was 72 years (interquartile range [IQR], 68-76 years) at primary operation, and 85% were men. Median preoperative aneurysm diameter was 60 mm (IQR, 53-66 mm). One hundred thirty-four vessels were targeted (mean, 2.5 per patient), and 96 TV stents were placed. The median clinical follow-up was 67 months (IQR, 37-90 months), and computed tomography follow-up was 60 months (IQR, 35-72 months). Aneurysm diameter decreased ≥ 5 mm in 39% ± 7% at 12 months, 64% ± 8% at 36 months, and 71% ± 8% at 60 months. Primary TV patency was 94% ± 2% at 12 months, 91% ± 3% at 36 months, and 90% ± 3% at 60 months. Glomerular filtration rate decreased by 17% at 59 months (IQR, 26-73 months) follow-up (60 [IQR, 46-79] vs 50 [IQR, 38-72] mL/min/1.73 m(2); P < .001), and one patient became dialysis-dependent secondary to a renal stent occlusion. Reintervention-free survival was 88% ± 5% at 12 months, 69% ± 7% at 36 months, and 56% ± 5% at 60 months. At least one reintervention was done in 37% of patients, of which 29% were endoleak-related, 26% TV-related, 13% graft-limb-related, and 32% due to other causes. The majority of reinterventions (68%) were based on complications detected on routine follow-up. Estimated overall survival was 93% ± 4% at 12 months, 76% ± 6% at 36 months, and 60% ± 7% at 60 months. In total, 54% of the patients died during the 10-year study period, where 9% died of aneurysm-related causes. Long-term mortality after f-EVAR is high, but most patients die from nonaneurysmal causes. Aneurysm-related mortality is associated with technical complications that can be reduced with increased experience. Reinterventions are common, and most complications are detected on routine follow-up.