Covered Stent Graft Research Articles

Covered Stent Graft for Relining of Occluded Femoro-popliteal Bypass

Introduction: Chronic long femoro-popliteal occlusions remain a significant challenge. In case of failure of endovascular procedures bypass surgery remains an important tool for revascularization in these patients. If both endovascular and open revascularization have failed the risk of major amputation is high. Methods: A 69-year old man with an extensive medical history including cardiac arrest, myocardial infarction, CABG and stroke presented with gangrene of his left forefoot. His vascular history included an occluded left sided above-the-knee prosthetic bypass with stents across the distal anastomosis and popliteal artery, an occluded left sided below-the-knee venous bypass and multiple left groin procedures for thrombectomies and correction of a false aneurysm of the proximal anastomosis of the above-the-knee bypass. Ultrasound guided retrograde puncture of the right common femoral artery was performed. A crossover sheath was placed and the occluded bypass was engaged. Unfortunately it proved impossible to cannulate either the occluded above- or below-the-knee bypasses. An attempt to recanalize the native femoral artery also failed due to the impossibility for reentry into the true lumen. Then a retrograde puncture of the popliteal stent was performed, a guidewire was advanced and the occluded above-the-knee bypass was cannulated in a retrograde way. After picking up the wire in the common femoral artery we then proceeded in an antegrade way and predilated the occluded bypass and occluded part of the popliteal artery. The occluded bypass was then relined with two 25 cm length covered stent grafts. At the end of the procedure the second and third toe of the left foot were amputated. He was discharged 2 days later. Results: During follow-up the wound of the amputation healed and he required no additional amputations. At 6 month follow-up the surveillance duplex ultrasound revealed a 80% distal edge stenosis which was treated succesfully with angioplasty. Conclusion: This is a case report of succesfull percutaneous relining of an occluded femoropopliteal bypass using covered stent grafts in a very high-risk patient with a history of multiple vascular procedures and an inaccessible ipsilateral groin. Disclosure: Nothing to disclose

Risk of Spinal Cord Ischemia After Treatment of Complex Aortic Aneurysms with Fenestrated or Branched Devices

Introduction -The aim of our study was to analyze the incidence of spinal cord ischemia (SCI) in patients presenting with complex aortic aneurysms treated with fenestrated (F-EVAR) and branched endovascular aortic aneurysm repair (B –EVAR), and identify risk factors associated with this complication. Methods - A retrospective study of prospectively collected data was undertaken including patients presenting with complex aortic aneurysm (para-renal and thoraco-abdominal; TAAA) treated with the F-EVAR or B-EVAR. The primary end point was the incidence of SCI and the assessment of any associated factors. Results - Between January 2011 and August 2017, a total of 243 patients (mean aneurysm diameter and age of 65.2±15.3mm and 72.4±7.5 years, respectively; 73% males) were treated with F-EVAR or B-EVAR. Asymptomatic patients presented in 73% (177/243) (in contrast to 27%; urgent) and in 52% (126/243) were treated for TAAA (in contrast to 48%; pararenal AAA). F-EVAR (mean number of fenestrations 3.3/case) or B-EVAR (mean number of branches 3.7/case) were undertaken in 67% (164/243) and 33% (79/243), respectively. The total incidence of SCI was 17.7% [43/243; paraplegia in 4% (10/243), paraparesis in 13.7% (33/243)]. Most of the patients with SCI presented immediate post-operative symptoms (72%; 31/43). Spinal drainage had been preoperatively placed in 53% (130/243) and was associated with the prevention of SCI (SCI with spinal drainage 12%; 16/130 vs. SCI without spinal drainage, 24%; 27/113, P=.018). The 30-day mortality rate was 9% (21/243). After multiple logistic regression analysis, SCI was associated with pre-operative renal function (SCI with pre-operative GFR<60, OR 2.43; 95% C.I. 1.18 – 4.99, P= .016) and number of vertebral segments covered (SCI with higher position of proximal stent in terms of vertebra, OR 1.2; 95% C.I. 1.1 – 1.3, P= .000). Similar outcome derives when height of proximal end of stent graft is replaced by total length of aortic coverage. (SCI with pre-operative GFR<60, OR 2.36; 95% C.I. 1.11 – 5.00, P= .025 and with longer length of aortic coverage, OR 1.01; 95% C.I. 1.003 – 1.009, P= .000). Conclusion - The majority of SCI after F-/or B-EVAR of complex aortic aneurysms present immediate post-operatively. The use of preoperative spinal drainage may prevent SCI. Patients with GRF <60 mL/min/1.73 m2 and with longer aortic length stent graft coverage are at higher risk SCI.

Initial Experience with the Begraft Balloon Expandable Covered Stent-Graft System for Endovascular Treatment of Penetrating Aortic Ulcer

Introduction - Penetrating aortic ulcer (PAU) is defined as ulceration of an aortic atherosclerotic plaque penetrating through the internal elastic lamina into the media. PAU is a rare pathology, often clinically silent, but potentially fatal when manifesting as an acute aortic syndrome (AAS). PAU can occur at any point throughout the aorta, most commonly in the middle and lower descending aorta, less frequently in the aortic arch, abdominal aorta and iliac arteries. Complicated PAU involves degeneration towards pseudoaneurysm formation, dissection or rupture. According to the guidelines uncomplicated type B PAU should be treated medically, and followed by serial imaging surveillance, whereas endovascular repair (EVAR) should be considered for symptomatic and complicated type B PAU.1 The present study reports a single center experience with treatment of patients with PAU using the second generation BeGraft balloon expandable covered stent graft system. Methods - Between 6/2017 and 12/2017 four patients with the mean age of 62 years (range 42-81 years), were treated with the endovascular procedure due to symptomatic abdominal aorta or iliac artery ulcer. The diagnosis of PAU was confirmed by computed tomography (CT) scan. PAUs were treated by implantation of the BeGraft balloon expandable covered stent graft system (Bentley InnoMed, Hechingen, Germany) using a transfemoral vascular access. The delivery of the graft to aorta was achieved through a right femoral artery cut open over an extra-stiff guide wire. The stent-graft was placed with a 14F sheath. In the first procedure aorta with PAU was covered using two 18 mm diameter and 48 mm long BeGraft stents. In the second patient two 24 mm diameter and 48 mm long stents were implanted. In case of the iliac localization the ulcer was covered with one 10.0 mm or 9.0 mm diameter and 57 mm long stent using 7F sheath. Technical success (defined as delivery and implantation of the stent-graft in the intended position with complete exclusion of the PAU), procedure-related complications and patency were evaluated. Results - In two patients the PAU of the abdominal aorta was treated, in the other two cases covered stents were implanted due to left common iliac artery ulcer. Average procedural time was 33.8 ± 8.8 min. All six stent grafts were successfully delivered and deployed. No peri-procedural complication or adverse events were noted. The average hospital stay was 4 days (range 3-5). After a mean follow-up of 225 days all stent grafts remained patent. During follow-up, no endoleak or ulcer recurrence were observed. Conclusion - Endovascular surgery remain the method of choice in treating penetrating aortic or iliac ulcer when intervention is indicated. Currently, the preferred and most commonly used endovascular approach for PAU is a standard EVAR with a bifurcated endograft. To date, none of the balloon expandable covered stents which are currently available in Europe have been specifically designed and evaluated for that purpose. This is so far the first reported endovascular therapy of PAU with BeGraft. Although this is off-label use, it can surely help the endovascular surgeon in some challenging situation when no standard stent-graft system is available. Endovascular repair of penetrating ulcer with BeGraft has excellent short-term results. Long-term follow-up is required to confirm these promising results. References1V. Riambau, D. Bockler, J. Brunkwall, et al. Management of Descending Thoracic Aorta Disease. Eur J Vasc Endovasc Surg (2017) 53, 4-52.

AAA 5. Bridging Stent Grafts in Fenestrated Aortic Repair: Performance of Different Covered Stents for This Indication in an In Vitro Model

The objective of this report was to study the performance of different covered stents as bridging stent grafts in a plain fenestrated model. Four different balloon-expandable covered stent grafts (Advanta V12 [Getinge AB, Gothenburg, Sweden], BeGraft [Bentley Innomed GmbH, Hechingen, Germany], BeGraft Plus [Bentley Innomed GmbH], and VBX [Gore Medical, Flagstaff, Ariz], each in 6 mm, 10 of each) were placed in a flat fenestrated model and flared by a 10-mm balloon. After this, the polytetrafluoroethylene (PTFE) fabric was analyzed by a micro camera (Keyence, Milton Keynes, United Kingdom). The stent structure was investigated by radiography. Pullout force was measured by recording force vs displacement to analyze the strength of the connection between the bridging stent graft and the fenestration. Tangential force vs displacement was measured to assess the shear stability of the different stents and to analyze the ability of the stents to resist migration and misalignment of a fenestrated endograft (Fig 1). No damage or rupture of the PTFE fabric was observed in all types of covered stents. Moreover, no stent fractures in any of the covered stents was seen by radiography. Maximal pullout force for 6-mm stents was 16.9 ± 1.9 N for the Advanta V12, 23.0 ± 4.3 N for the VBX, 17.6 ± 1.3 N for the BeGraft, and 28.1 ± 4.2 N for the BeGraft Plus. The slope of the measured pullout force of these stents in the first part was 2.83 N/mm for the Advanta V12, 1.9 N/mm for the VBX, 1.87 N/mm for the BeGraft, and 2.12 N/mm for the BeGraft Plus. Maximal shear strength was 29.6 ± 3.2 N for the Advanta V12, 20.4 ± 3.1 N for the VBX, 18.9 ± 1.9 N for the BeGraft, and 28.8 ± 2.0 N for the BeGraft Plus. Shear force at 6-mm displacement was 7.2 ± 1.4 N for the Advanta V12, 8.7 ± 1.9 N for the VBX, 6.7 ± 0.8 N for the BeGraft, and 9.6 ± 1.5 N for the BeGraft Plus (Fig 2). The material of all tested covered stents has withstood the flaring forces without damage of the PTFE fabric or stent fracture. Pullout force was highest in the BeGraft Plus, followed by VBX, BeGraft, and Advanta V12, but the slope of the pullout force at the first part was highest in the Advanta V12 stent, followed by BeGraft Plus, VBX, and BeGraft. The ability to withstand crushing forces was highest in Advanta and BeGraft Plus, followed by VBX and BeGraft. These findings together with the special features of the tested stents should have an important implication for clinical practice. Fatigue tests for these stents in this special indication are mandatory to ave a dedicated bridging stent graft for fenestrated aortic repair in the future.Fig 2Shear strength 6-mm bridging stent graft.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Suivi clinique après implantation d’un stent couvert dans l’artère fémorale commune au décours immédiat d’une complication vasculaire per-TAVI

BackgroundVascular complications are frequent in the context of transcatheter aortic valve replacement and may require the implantation of a covered stent graft in the common femforal artery. However, common femoral artery is considered to be at high risk of stent fracture or occlusion due to high mobility of the hip joint. Patients and methodsWe analyzed medical records of patients with transcatheter aortic valve replacement related vascular complications between 2015 and 2018, treated with commom femoral artery transluminal angioplasty or surgery. Vascular complications or suspect symptoms were followed up by phone calls. ResultsAmong 552 patients, 43 patients were included. Twelve (11.6 %) were managed by prolonged balloon inflation, 5 (11.6 %) by first line surgery and 26 (60.4 %) by the implantation of a covered stent graft. Among the latter group, the covered stent graft was efficient in 24 patients (92.3 %). The median follow-up was 430 days [3–1499]. The first-line surgery group had a higher risk of red blood cell transfusion and all causes mortality. At follow-up, no patient had suspicious symptoms of vascular covered stent complication. Four patients (9.3 %) had US-doppler or CT vascular imaging at follow-up, showing no evidence of stent fracture or occlusion. ConclusionIn our study, the implantation of a covered stent graft in the common femoral artery was an efficient and safe strategy for the management of transcatheter aortic valve replacement related vascular complications.

STABLE II clinical trial on endovascular treatment of acute, complicated type B aortic dissection with a composite device design

ObjectiveTo evaluate the safety and effectiveness of a composite device design (covered stent graft and bare metal stent) for the treatment of patients with acute, complicated type B aortic dissection (TBAD) presenting with aortic rupture and/or branch vessel malperfusion. MethodsIn this prospective, nonrandomized, multicenter study, 73 patients (65.8% male; mean age, 60.7 years) with acute, complicated TBAD were enrolled between August 2012 and January 2015 to receive treatment with the Zenith Dissection Endovascular System (William Cook Europe, Aps, Bjaeverskov, Denmark) at institutions in the United States and Japan. The primary safety end point was the rate of freedom from major adverse events at 30 days, and the primary effectiveness end point was the rate of survival at 30 days. This article reports primary outcomes at 30 days and follow-up results through 1 year, reflecting study data as of March 2018. ResultsOf 73 patients, 20 presented with aortic rupture (27%) and 57 presented with branch vessel obstruction/compromise (78%), including 4 patients presenting with both conditions. The covered stent graft was used in all patients (median, 1; range, 1-3; 1 stent graft used in 64.4%; 47/73), and the bare metal dissection stent was used in 58 of 73 patients (79.5%). Thirty-day mortality occurred in five patients (6.8%): one procedure related, three unrelated to dissection repair, and one indeterminate. Thirty-day major adverse events included myocardial infarction (1.4%), bowel ischemia (1.4%), renal insufficiency/renal failure requiring dialysis (6.8%), stroke (6.8%), paraplegia or paraparesis (5.5%), and prolonged ventilatory support (13.7%). Nine deaths occurred from 31 to 365 days (only one death related to dissection repair); the Kaplan-Meier estimate of freedom from all-cause mortality was 80.3% ± 4.7% at 1 year. Within 365 days, 9 of 73 patients (12.3%) underwent 10 secondary interventions; no patients required conversion to open surgery. At the 12-month follow-up, complete or partial thrombosis of the false lumen was seen in 100% of patients (46/46) within the stent graft region and in 97.4% of patients (38/39) within the dissection stent region. Growth (>5 mm) of the maximum transaortic diameter was observed in 14.9% of patients (7/47) in the stent graft region and in 38.5% of patients (15/39) within the dissection stent region at 12 months. ConclusionsThirty-day and 1-year results from the STABLE II study demonstrated favorable clinical and anatomical outcomes for the treatment of rupture and malperfusion in the setting of acute, complicated TBAD. Five-year follow-up is ongoing.

Lumbar Drain Complications in Patients Undergoing Fenestrated/Branched Endovascular Aortic Aneurysm Repair

Lumbar drain placement, with cerebrospinal fluid (CSF) drainage, has been demonstrated to be an effective adjunct for reducing the risk of spinal cord ischemia in patients undergoing complex aortic aneurysm repair. However, lumbar drain placement is a challenging procedure and can be associated with significant complications. We sought to characterize complications occurring as a result of lumbar drain placement in a large, single-center experience of patients who underwent fenestrated/branched endovascular aneurysm repair (F/BEVAR). All patients who underwent F/BEVAR and attempted lumbar drain placement from 2010 to 2019 were retrospectively reviewed. At our institution, all lumbar drains are placed by four cardiovascular anesthesiologists who compose the complex aortic anesthesia team. Lumbar drain placement is guided by a set protocol and used whenever the aortic stent graft coverage is planned to extend more proximal than 40 mm above the celiac artery. Details relating to lumbar drain placement, management, frequency, and type of associated complications were characterized. During the study period, 256 patients underwent F/BEVAR, of whom 100 (39%) were planned for lumbar drain placement. Successful placement occurred in 98 (98%) of the cases. All lumbar drains were placed before induction of general anesthesia, with use of fluoroscopy guidance in 28 cases (28%). The most common level of placement was L4-5 (n = 42 [42%]). The majority (n = 82 [82%]) were left in place ≤48 hours, with 21% removed during the first 24 hours and 61% removed between 24 and 48 hours. Nonfunctionality was the most common complication, occurring in 16 (16%) patients. Catheter dislodgment/fracture, CSF leak, and postdural puncture headache were observed in four (4%), seven (7%), and four (4%) patients, respectively. The most common bleeding complication was the presence of asymptomatic blood in the CSF (n = 11 [11%]), whereas subarachnoid hemorrhage combined with intraventricular hemorrhage occurred in three patients (3%); none of these patients required surgical drainage or intervention. No infectious complications were observed. Lumbar drain placement for CSF drainage is a commonly employed adjunct to prevent spinal cord ischemia in F/BEVAR. Our experience demonstrates that lumbar drain placement can be performed successfully, with low complication rates, in experienced centers.

IP133. Successful Repair of an Arteriovesical Fistula as a Complication After Coil Embolization for Right Hypogastric Artery Aneurysm

We describe a complicated repair of an arterio-vesical fistula from a percutaneous arterial embolization for a right hypogastric artery aneurysm. One patient case report. An 84-year-old man presented to outpatient clinic for gross hematuria. He was several years status post excluding stent graft coverage and incomplete outflow coil embolization of a right internal iliac artery aneurysm. The aneurysm continued to enlarge owing to type II endoleak and multiple percutaneous translumbar coil embolizations. Four years after the last embolization intervention, he was seen by urology for hematuria and cystoscopy showed several vascular embolization coils extruding into his bladder (Fig 1). Computed tomography angiography and transfemoral catheter angiography confirmed resolution of the endoleak and revealed a very large right internal iliac artery aneurysm, defined by the coils that extended toward midline (Fig 2). There were no overt signs of sepsis. Given the extent of the bladder injury, the persistent hematuria, and exposure of the previous endograft to the genitourinary contents, he underwent a joint open repair of the bladder with urology. We revascularized with a left-to-right femoral-femoral bypass graft through clean incisions. Via midline laparotomy, we removed in entirety the iliac endograft and all the coils. The right external and common iliac arteries were isolated and oversewn. The bladder was repaired primarily. While no pus was encountered the coils were found extruding out the aneurysm into the retroperitoneum. Graft cultures grew Staphylococcus epidermidis. Patient received long term antibiotic treatment. On follow-up, he is doing well and has had complete healing of the bladder. Arteriovesical fistula is a rare pathology and should be suspected in patients with hypogastric artery aneurysm and hematuria.Fig 2Very large right internal iliac artery aneurysm.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Long-term results of the heparin-bonded Viabahn stent graft in femoropopliteal TASC C and D lesions with a covered stent length of minimum 25 cm.

Background Heparin-bonded covered stent grafts (Viabahn) are used to treat femoropopliteal long-segment arteriosclerotic lesions. The aim of this study was to evaluate the long-term outcome of Viabahn grafts with a covered stent length of minimum 25 cm. Methods We conducted a retrospective analysis of patients receiving a heparin-bonded stent graft in our clinic who met the length criteria between July 2010 and March 2018. Primary endpoints were patency rates, limb salvage and survival after five years. Secondary endpoint was the 30-day outcome including early complications. Results A total of 62 patients (45 male, median age 70.5 years) were included. The median arteriosclerotic lesion length was 25 cm (22.0–41.3 cm), the minimum covered stent length was 25 cm (25–46 cm). All lesions were TASC C and D lesions. The 30-day mortality was 0%, an early stent graft occlusion occurred in 8.1%. A major amputation was performed in 1.6%. Primary patency, primary assisted patency, secondary patency, limb salvage and survival were 38.5%, 45.7%, 52.4%, 92.8% and 68.9% after five years. Distal stent graft end below the femoral condyles and critical limb ischemia was associated with a significant decreased survival. The diameter of the stent had no influence on the outcome. Conclusion The Viabahn stent graft for long segment arteriosclerotic lesions is a feasible treatment with adequate long-term results.

A modified endovascular treatment protocol for iatrogenic internal carotid artery injuries following endoscopic endonasal surgery.

Internal carotid artery (ICA) injuries during endoscopic endonasal surgery (EES) are catastrophic complications. Alongside the advancements in medical instrumentation and material, there is a need to modify previous treatment modalities and principles. A retrospective review of 3658 patients who underwent EES performed at the authors' institution between January 2012 and December 2017 was conducted. Ultimately, 20 patients (0.55%) with ICA injury following EES were enrolled for analysis. Data collection included demographic data, preoperative diagnosis, injury setting, repair method, and immediate and follow-up angiographic and clinical outcomes. Among the 20 patients, 11 received immediate endovascular therapy and 9 were treated only with packing. Of the 11 patients who received endovascular treatment, 6 were treated by covered stent and 5 by parent artery occlusion (PAO). The preservation rate of injured ICA increased from 20.0% (1 of 5) to 83.3% (5 of 6) after the Willis covered stent graft became available in January 2016. Of the 20 patients in the study, 19 recovered well and 1 patient-who had a pseudoaneurysm and was treated by PAO with a detachable balloon-suffered epistaxis after the hemostat in her nasal cavity was removed in ward, and she died later that day. The authors speculated that the detachable balloon had shifted to the distal part of ICA, although the patient could not undergo a repeat angiogram because she quickly suffered shock and could not be transferred to the catheter room. After the introduction of a hybrid operating room (OR), one patient whose first angiogram showed no ICA injury was found to have a pseudoaneurysm. He received endovascular treatment when he was brought for a repeat angiogram 5 days later in the hybrid OR after removing the hemostat in his nasal cavity. Of the 4 surviving patients treated with PAO, no external carotid artery-ICA bypass was required. The authors propose a modified endovascular treatment protocol for ICA injuries suffered during EES that exploits the advantage of the covered stent graft and the hybrid OR. The endovascular treatment protocol used in this study for ICA injuries during EES was helpful in the management of this rare complication. Willis stent placement improved the preservation rate of injured ICA during EES. It would be highly advantageous to manage this complication in a hybrid OR or by a mobile C-arm to get a clear intraoperative angiogram.

Early- and long-term results of thoracic endovascular aortic repair for blunt traumatic thoracic aortic injury: a single-centre experience.

Endovascular repair has been proposed as an alternative to classical surgical repair for the management of blunt traumatic thoracic aortic injury. However, the long-term outcomes of endovascular repair and the risks of left subclavian coverage remain unclear. From April 2001 to August 2018, 33 patients with blunt traumatic thoracic aortic injury underwent endovascular repair in our institution. A follow-up computed tomography and a clinical examination were performed before discharge and at 1 month, and yearly or every 2 years thereafter. The mean age was 45 ± 19 years. The technical success rate was 100%. Complete coverage of the left subclavian artery (LSCA) was performed in 20 patients (60.6%). Among 20 patients with coverage of the LSCA, revascularization was performed in 1 patient. No in-hospital deaths occurred. The clinical follow-up rate was 97%, with a mean period of 7 years and a maximum of 18 years. The survival rates were 100% at 1 year, 95% at 5 years and 88.7% at 10 years after the event. Among the 5 patients (20%) who developed neurological complications, 1 who had undergone implantation of a 200-mm long stent graft and LSCA coverage without revascularization developed paraplegia during the long-term follow-up. This study demonstrates that the endovascular treatment of blunt traumatic thoracic aortic injury is a safe and effective therapeutic method over a long-term follow-up period. LSCA coverage and long stent graft placement might be indications for revascularization to prevent spinal cord injury.

Midterm results of laser generated in situ fenestration of the left subclavian artery during thoracic endovascular aneurysm repair

ObjectiveTo analyze the midterm result of in situ fenestration (ISF) of the left subclavian artery (LSA) during thoracic endovascular aneurysm repair (TEVAR). MethodsIn this clinical study, between 2014 and 2016, ISF for LSA revascularization was attempted during TEVAR in 10 patients (7 males; median age, 68 years). An excimer laser, placed from the left brachial artery, was used to create a fenestration and all fenestrations were stented with covered stent grafts. Follow-up included computed tomography scans 1 month postoperatively and annually thereafter. Survival was analyzed according to Kaplan-Meier. ResultsNine of the 10 laser-assisted ISF were successful. No 30-day mortality occurred. One patient had a transient ischemic attacked in the left carotid territory. After a median follow-up of 27 months, all fenestrations were patent. At 1 month, computed tomography follow-up showed nonspecific endoleaks of unknown origin in five of the nine patients. At 27 months follow-up, only two endoleaks remained. One reintervention was done after 24 months owing to a type Ic endoleak from the LSA. Overall TEVAR success, defined as survival with no aneurysm expansion, was eight of nine. One patient showed aneurysm expansion after 14 months. Two deaths occurred (at 33 and 31 months postoperative), one of unknown reason and one aneurysm related. ConclusionsLaser fenestration might be an option for LSA revascularization during emergent or semiurgent TEVAR and electively in patients with hostile neck anatomy (eg, previous neck radiation, short and adipose necks) that might make a carotid–subclavian bypass difficult. The LSA fenestration has excellent patency and TEVAR success was not affected by nonspecific endoleaks around the LSA.

Stent graft coverage of dual-stent strategy in the management of abdominal aortic aneurysms

Treating an abdominal aortic aneurysm (AAA) with a stent graft (SG) and a multilayer stent (MS) is a key technology in isolating flow fields. Clinically, dual stents (an SG in the proximal and an MS in the distal of AAA) are used for treatment of AAA, but only a few studies have examined the relationship between SG coverage and treatment effects. Through numerical simulation of the hemodynamics after SG and MS implantation, the SG coverage and position were simulated at 0% (0 mm), 25% (13.75 mm), 50% (27.5 mm), and 75% (41.25 mm). With increasing SG coverage, the pressure on the aneurysm sac wall and the flow of branch vessels gradually decreased, and the lower wall shear stress (WSS) gradually increased. The changes in pressure, lower WSS, and the mass flow rate of the branch vessels did not change significantly. The coverage of the SG has a nonsignificant effect on hemodynamics in the treatment of AAA; the implantation position need not be very precise. This research can provide theoretic support for clinicians’ decision-making.

Risk of spinal cord ischemia after fenestrated or branched endovascular repair of complex aortic aneurysms

ObjectiveThe aim of our study was to analyze the incidence of spinal cord ischemia (SCI) in patients presenting with complex aortic aneurysms treated with endovascular aneurysm repair (EVAR) and to identify risk factors associated with this complication. MethodsA retrospective study was undertaken of prospectively collected data including patients presenting with complex aortic aneurysm (pararenal abdominal aortic aneurysm and thoracoabdominal aortic aneurysm) treated with fenestrated EVAR (F-EVAR) or branched EVAR (B-EVAR). The primary end point was the incidence of SCI and the assessment of any associated factors. ResultsBetween January 2011 and August 2017, a total of 243 patients (mean aneurysm diameter, 65.2 ± 15.3 mm; mean age, 72.4 ± 7.5 years; 73% male) were treated with F-EVAR or B-EVAR. Asymptomatic patients were treated in 73% of the cases (177/243, in contrast to 27% urgent), and 52% (126/243) were treated for thoracoabdominal aortic aneurysm (in contrast to 48% for pararenal abdominal aortic aneurysm). F-EVAR (mean number of fenestrations, 3.3/case) and B-EVAR (mean number of branches, 3.7/case) were undertaken in 67% (164/243) and 33% (79/243), respectively. The total incidence of SCI was 17.7% [43/243; paraplegia in 4% (10/243) and paraparesis in 13.7% (33/243)]. Most of the patients with SCI presented with immediate postoperative symptoms (72% [31/43]). A spinal drain was preoperatively placed in 53% (130/243) and was associated with the prevention of SCI (SCI with spinal drainage, 12% [16/130]; SCI without spinal drainage, 24% [27/113]; P = .018). The 30-day mortality rate was 9% (21/243). After multiple logistic regression analysis, SCI was associated with preoperative renal function (SCI with preoperative glomerular filtration rate <60 mL/min/1.73 m2: odds ratio [OR], 2.43; 95% confidence interval [CI], 1.18-4.99; P = .016) and the number of vertebral segments covered (SCI with higher position of proximal stent in terms of vertebra: OR, 1.2; 95% CI, 1.1-1.3; P = .000). A similar outcome was derived when the height of the proximal end of the stent graft was replaced by the total length of aortic coverage (SCI with preoperative glomerular filtration rate <60 mL/min/1.73 m2: OR, 2.36 [95% CI, 1.11-5.00; P = .025]; SCI with longer length of aortic coverage: OR, 1.01 [95% CI, 1.003-1.009; P = .000]). ConclusionsThe majority of SCI incidence after F-EVAR or B-EVAR of complex aortic aneurysms is manifested immediately postoperatively. The use of preoperative spinal drainage may prevent SCI. Patients with GRF <60 mL/min/1.73 m2 and with longer aortic stent graft coverage are at higher risk of SCI.

Invited commentary

Treatment of dissection of the aorta remains one of the great challenges in vascular surgery, but one in which steady progress has been made. In years past, even making the diagnosis was difficult, and the best means of doing so was a matter of controversy. The universal availability of high-speed and high-quality computed tomography scanning now requires only a low index of suspicion before an accurate picture of the anatomic nature of the dissection can be defined. The clinical question, therefore, no longer is What is the diagnosis? but rather What is the best course of action? As vascular surgeons, we must remember that our fundamental rules about intervention in the case of a type B dissection were built on a risk-benefit ratio calculated when options for treatment involved medical management or the performance of a very substantial operation (open fenestration or emergency thoracoabdominal aortic replacement) that favored medical management the overwhelming percentage of the time. The availability of appropriate covered stent grafts, the development of intravascular ultrasound, and the availability of hybrid imaging and operative environments helped shift the calculation of the risk-benefit ratio dramatically toward intervention. We are still trying to define the role of intervention in the treatment of this pathologic process.1Ulug P. McCaslin J.E. Stansby G. Powell J.T. Endovascular versus conventional medical treatment for uncomplicated chronic type B aortic dissection.Cochrane Database Syst Rev. 2012; 11: CD006512PubMed Google Scholar, 2Nienaber C.A. Rousseau H. Eggebrecht H. Kische S. Fattori R. Rehders T.C. et al.Randomized comparison of strategies for type B aortic dissection: the INvestigation of STEnt Grafts in Aortic Dissection (INSTEAD) trial.Circulation. 2009; 120: 2519-2528Crossref PubMed Scopus (563) Google Scholar The classic anatomic division of vascular surgery territory from cardiothoracic surgery territory just distal to the left subclavian artery has been pushed proximally in the aorta by debranching procedures and snorkel/chimney adaptations to stent grafts. In spite of this advancing level of skill set and ingenuity, the treatment of the type A aortic dissection has been firmly in the hands of the cardiac surgeons, in which only incremental advances have been made in a maximally invasive operative technique, with outcomes leaving much room for improvement. Although the postmortem deployment of a surgeon-modified graft in a flow model using a nondiseased aortic arch specimen is a preliminary study, the endovascular approach to the treatment of this pathologic process is a logical extension of the ideas and skills developed from work done on type B dissections and the transcatheter aortic valve replacement procedures. Where will this lead us? Imagination and ingenuity have forged ahead of the availability of devices that will eventually be developed as standardized approaches become adopted. Will access to the ascending aorta be transapical, as in this report, or transfemoral or even transvenous/trans-septal? The invasiveness and outcomes of the open repair of type A dissections make the endovascular approach to the treatment of ascending aortic dissection a pursuit whose time is coming. Experimental evaluation of homemade distal stent graft fenestration for thoracic endovascular aortic repair of type A dissection by a transapical approachJournal of Vascular SurgeryVol. 68Issue 4PreviewThe use of off-the-shelf stent grafts for thoracic endovascular aortic repair of type A dissections is limited by variability in both the length of the ascending aorta and the location of the proximal intimal tear. This experimental study aimed to assess the feasibility of using a physician-modified thoracic aortic stent graft to treat acute type A dissection by a transapical cardiac approach. Full-Text PDF Open Archive

Endovascular Rescue of Simultaneous Renal Stent Thrombosis: Case Report

The chimney/periscope technique has been used to address complex aortic pathologies. This case report aims to report the outcomes of the endovascular management of the acute and simultaneous thrombosis of both renal covered stent grafts after bilateral renal arteries chimney technique for endovascular repair (CH-EVAR) of a juxtarenal abdominal aortic aneurysm. The cause of this early occlusion of stent grafts may be related to how procedures and devices combinations alter the native anatomy. The authors aimed to compare renal artery geometry before and after CH-EVAR to find a possible cause of stent thrombosis.

A Narrative Review on Contrast-Enhanced Ultrasound in Aortic Endograft Endoleak Surveillance.

Endovascular repair of abdominal aortic aneurysms have been performed successfully since 1991. However, 20% to 50% of these patients may develop an endoleak or continued aneurysmal sac expansion or perfusion despite stent graft coverage. Current recommendations suggest lifelong surveillance with computed tomographic angiography (CTA) at least 1 month after intervention and yearly after that. In select patients with a stable aneurysm sac on computed tomography performed 1 year after treatment, future screening could be performed with ultrasonography. However, color Doppler ultrasound can fail to detect as many as 31% of endoleaks. Contrast-enhanced ultrasound (CEUS) provides an alternative approach to excluded aneurysm sac follow-up imaging. The Society for Vascular Surgery notes a need for further research on the role of CEUS in endovascular aortic repair surveillance. The European Federation of Societies for Ultrasound in Medicine and Biology suggests that early results are promising. Meta-analyses report pooled sensitivities and specificities of CEUS compared with CTA for the detection of endoleak between 89% and 98% and 86% and 88%, respectively. Owing to the dynamic flow information it provides, CEUS may actually be more sensitive than CTA at detection and characterization in select circumstances. Challenges with adoption, patient selection, and operator dependency remain, but current and future research suggests a role for CEUS in endoleak surveillance.

Complete Endovascular Arch Reconstruction With a Multibranch Device for the Management of Aortic Arch Aneurysm

Open surgical repair through median sternotomy remains the standard of care for aortic arch aneurysms; however, such operative approach is associated with significant morbidity and mortality. New endovascular technology now allows us to treat those patients who are poor candidates for open surgical repair. The patient is a 57-year-old man who we have been observing for an expanding aortic arch aneurysm. During the last 3 years, this has grown in size from 53 to 64 mm. Given his multiple cardiac and pulmonary comorbidities, our cardiothoracic colleagues have deemed him a poor candidate for open repair. Based on radiologic imaging, he was found to have appropriate anatomy for a branched endovascular reconstruction. The operation was performed in collaboration with the cardiothoracic surgery team. At the start of our operation, a left-sided carotid-subclavian arterial bypass was created. Open access to the right carotid and left femoral arteries was also employed. The main thoracic endograft, incorporating two internal branches, was delivered from the femoral artery and deployed in zone 0 under rapid ventricular pacing. The internal branches were cannulated from the left and right common carotid arteries. Self-expanding covered stent grafts were deployed into the internal branches, extending to the innominate and left common carotid arteries. The proximal left subclavian artery was occluded with an endovascular plug. He was discharged home in stable condition on postoperative day 7. Follow-up outpatient imaging revealed an intact repair with no endoleak. Branched endovascular technology will allow us to treat aortic arch disease not readily amenable to open surgical repair. Early experience with multibranch endovascular arch devices is promising.

Stent fractures after common femoral artery bail-out stenting due to suture device failure in TAVR

Vascular access site-related complications are frequent in the context of transfemoral transcatheter aortic valve replacement (TAVR). The implantation of a covered stent graft is an effective treatment option for bleeding control. However, the external iliac and common femoral arteries are exposed to flexion of the hip joint. Therefore, stent compression and stent/strut fractures may occur, facilitating stent occlusion. In all 389 patients who received transfemoral TAVR from 2013-2015 at the Düsseldorf Heart Centre, we monitored the management of vascular access site-related complications. Our analyses focused on immediate technical success and bleeding control, primary patency, and the occurrence of stent/strut fractures after six to 12 months of follow-up. Vascular access site-related complications occurred in 13 % (n = 51), whereof in 10 patients, the bleeding was successfully managed by prolonged compression. In 40 out of 51 patients, a covered stent graft was implanted in the common femoral artery, leading to 100 % immediate bleeding control. After a mean follow-up of 334 ± 188 days, 28 stents out of 29 patients with completed follow-up (excluding e. g. death) were without flow-limiting stenosis (primary patency 97 %) or relevant stent compression (diameter pre/post 8.6/8.1 mm, p = 0.048, late lumen loss 1.1 ± 0.2 mm, mean flow velocity 92 ± 34 cm/s). In four asymptomatic patients, stent/strut fractures were detected (14 %) without flow-limiting stenosis. The implantation of a covered stent graft is highly effective and safe to control vascular access site-related complications after TAVR. Stent/strut fractures in the flexible segment of the common femoral artery may occur, as consequently verified by X-ray visualization, but show no impairment on flow or clinical parameters after six to 12 months.

Technical issues and clinical outcomes of endovascular repair of isolated iliac artery aneurysms: A single-center experience.

Isolated iliac artery aneurysms are the relatively uncommon condition. This study aims to evaluate the technical issues and clinical outcomes of endovascular repair in a cohort of isolated iliac artery aneurysms treated. We retrospectively reviewed 22 consecutive patients with isolated iliac artery aneurysms between December 2006 and September 2016. Iliac artery aneurysms were treated in one of the three ways: (1) standard bifurcated aortic stent graft placement with limb extension; (2) coverage of iliac artery aneurysms with covered stent grafts; and (3) embolization of the arterial branches distal to the aneurysms with coils or vascular plugs. Twenty-two patients (20 men) with a mean age 64.7 years underwent endovascular repair during the study period. The median diameter of the isolated iliac artery aneurysms was 5.9 ± 1.7 cm (2.9-9.0 cm). Technical success was 95.5%. Conversion to open surgery was performed in one patient with bilateral internal iliac artery aneurysms. Four patients underwent placement of a bifurcated stent graft. A covered stent graft was deployed in 16 patients, with embolization of internal iliac artery in 14 patients. Simple coil embolization of isolated internal iliac artery aneurysm was performed in one patient. There was one sudden cardiac death on day 4 after the procedure due to heart failure. During the follow-up period (range: 1-50 months, mean 19.8 months), five patients died of causes not related to isolated iliac artery aneurysms, and transient buttock claudication was observed in one patient. Our study documents the safety and effectiveness of endovascular repair of isolated iliac artery aneurysms with low morbidity and mortality.