Biocompatibility between stent graft and abdominal aorta

To evaluate the biocompatibility between the domestic stent-graft and abdominal aorta.Methods We made stent-graft with felting of expanding-polytetra- fluroethylene (ePTFE) graft and nitinol stent.They were implanted in the subrenal abdominal aorta.The specimes were taken out 2,4,12 weeks afterwards and underwnet HE/special pigmentation of collagen and elastin,immunohistochemistry of α actin from vascular smooth muscle cells(VSMC),in-situ apoptosis detection and scan of electromicroscopy.The comparison between them and normal abdominal aorta in intimal thickness,relative content of collagen and elastin,density and apoptosis ratio of VSMC in medium was made through the image analysis.Results The stent-graft was covered with intima as early as 2 weeks but suffered more severe intimal hyperplasia all the time (P<0.01).The morphology and distribution of collagen and elastin were generally normal in the experimental group (P>0.05).However,its density and apoptosis ratio of VSMC in medium were significantly higher than in the normal ones (P<0.01) in 2,4 weeks.Conclusion The stent-graft shared fine biocompatibility with the abdominal aorta except for the significant intimal hyperplasia.3 refs.

Case Report of a Pseudoaneurysm of Ascending Aorta Treated by Stent

Pseudoaneurysms of the ascending aorta are a rare complication of aortic and cardiac surgery. In this article, we present a clinical case of a 56-year-old patient with a fortuitous diagnosis of a pseudoaneurysm of ascending aorta that was treated by an endovascular stent-graft. We discuss in this article the diagnostic and therapeutic aspect of the case and the place of endovascular treatment for the ascending aorta.

Custom Made Fenestrated Stent Graft Collapse after Thoracic Endovascular Aortic Repair: A Case Report

We present a case of stent graft collapse after performing thoracic endovascular aortic repair with a custom-made fenestrated stent graft. The patient was a 70-year-old woman with an asymptomatic aneurysm of the distal aortic arch, and thoracic endovascular aortic repair was performed. The patient showed a blood pressure difference between the left arm and the right arm on postoperative day (POD) 17 prompting the performance of a chest computed tomography scan which revealed stent graft collapse. She then underwent staged debranching of thoracic endovascular aortic repair. Stent graft collapse is a rare but well-described complication of thoracic endovascular repair. Therefore, patients who undergo such a procedure should be carefully monitored for signs and symptoms, which suggest the possibility of stent collapse.

Surgical strategies for severely atherosclerotic(porcelain)aorta during coronary artery bypass grafting

Porcelain aorta(PA)is an asymptomatic atherosclerotic disease,characterized by circumferential calcification throughout the whole perimeter of the aorta.It is seen in 2%to 9.3%of patients undergoing elective coronary artery bypass grafting(CABG)and makes manipulation of the ascending aorta impossible.It has been clearly shown that most emboli seen and detected during the CABG procedure occur during aortic cross-clamping and aortic side-clamping.Manipulation of porcelain or a severely atherosclerotic aorta increases the risk of perioperative stroke.The incidence of stroke after CABG is between 0.48%and 2.9%,and the risk is correlated with the extent and severity of the atherosclerotic disease.A conventional CABG procedure involves successive steps that include cannulation of the ascending aorta,application of a cross-clamp to the aorta,and partial clamping of the aorta to create the proximal anastomosis.Therefore in procedures that involve cannulation,clamping,or proximal anastomosis,and where aortic manipulation is inevitable,preassessment of the atherosclerotic aortic plaques is crucial.Although many surgeons still rely on intraoperative manual aortic palpation,this approach has very low sensitivity and underestimates the severity of the atherosclerotic illness.Imaging methods including preoperative computed tomography or intraoperative epiaortic ultrasonography enable modification of the surgical technique according to the severity of atherosclerosis.Various surgical techniques have been described to reduce the risk of atheroembolism that may lead to cerebrovascular events in patients with severely atherosclerotic ascending aorta.Anaortic or“no-touch”techniques that do not utilize aortic manipulation may significantly decrease the development of neurological complications by avoiding aortic maneuvers known to cause emboli.In cases where severe atherosclerotic disease or other factors preclude safe use of the ascending aorta,modifications in the surgical techniques,such as switching to different cannulation sites including the axillary/subclavian,femoral and innominate arteries,or using hypothermic ventricular fibrillation and in-situ pedicled arterial grafts,or performing proximal anastomoses at alternative anatomical locations will enable CABG operations to be performed safely with low morbidity and mortality rates in patients with porcelain aortas.

Progress of research on the biomechanics of aorta and stent graft

With improvements in the technology of clinical diagnosis of aortic diseases, more and more cases have been found on such vascular lesions as aortic dissection and abdominal aortic aneurysm, which lead to aortic biomechanical changes. Aortic biomechanics research will become a hot spot in the near future. At the same time, stent grafts （SGs） are widely used in the endovascular treatment of vascular diseases. The biomechanical properties of SGs will also become a focus of research. Understanding the relation between the aorta and SGs will better cater to clinical services by improving the success rate of surgery for aortic diseases and reducing intraoperative and postoperative complications. This article reviews researches on the biomechanics of the aorta and SGs.

Angioscopic Observation of an Endoluminal Stent Graft: CT Imaging versus Angioscopic Imaging

We could observe the endoluminal stent graft (SG) following thoracic endovascular aneurysm repair (TEVAR) by a coronary artery angioscope and establish intravascular visualization of SG. The patient was a 70-year-old woman with the distal aortic arch aneurysm and the descending aortic aneurysm, and debranching TEVAR were performed. After 12 months follow up, urgent hospitalization was required for chest pain, and cardiac catheter examination with a coronary artery angioscope was performed. The endoluminal SG was observed. The observation in angioscope which is a video image is better than CT that is a still image, and observation in blood vessel or SG is possible. It may be possible to observe the endoluminal SG, allowing potential investigation of an endoleak, or the covering status of the SG with the native aortic vessel wall, or the state of intimal membrane formation in the endoluminal graft.

Acute Type A Aortic Dissection—Replacement of Ascending Aorta, Aortic Arch and Antegrade Stenting of the Descending Thoracic Aorta Using the Thoraflex™Hybrid Plexus Device (Terumo Aortic)—“Frozen Elephant Trunk”: The Plymouth Way!

Objectives: To describe our technique for the implantation of the Thoraflex Hybrid prosthesis for replacement of the aortic arch in a safe and reproducible way. Materials: Thoraflex™ Hybrid Plexus Device (Terumo Aortic). Design: Drawing on our own experience over the past 4 years in the management of acute type A aortic dissection, we have distilled the essentials of our “Frozen Elephant Trunk” technique which have led us through our own learning curve to the improved management of this taxing condition. Method/ Results: Small extension of the median sternotomy incision along the medial border of sternocleidomastoid muscle. End to side graft anastomosis near the origin of the left subclavian artery during cooling on bypass towards 20 degrees. Attention to cardiac protection and maintenance of cerebral perfusion during the shortened corporeal arrest period. Excellent results in 24 consecutive AAAD patients with just one hospital mortality. Conclusions: We believe we are entering a new phase in the treatment of AAAD, facilitated by the availability of a hybrid prosthesis which combines expanding stent technology with familiar surgical graft material. Our particular management of the left subclavian artery and of the cerebral circulation during implantation has contributed to an expeditious and reproducible method of treating dissection within the arch of the aorta and beyond.

NuMED CHEATHAM-PLATINUM STENT AND BALLOON IN BALLOON DELIVERY CATHETER FOR TREATMENT OF NATIVE COARCTATION OF THE AORTA

COARCTATION of the aorta (CoA) is a congenital heart defect involving a narrowing of the aorta.The narrowed segment called coarctation is most likely to happen in the segment just after the aortic arch.The narrowing can be removed by surgery or sometimes by a nonsurgical balloon dilation.However, aortic coarctation may recur even after successful surgery or balloon dilation.Fortunately, coarctation can now be treated with nonsurgical balloon dilation associated with implanting a stent using cardiac catheterization.Herein we reported our experience in a 19-year-old boy with CoA who underwent successful covered Cheatham-Platinum (CP) stent implantation for the coarctation.

Viabahn Stent Graft for Inadvertent Insertion of a Central Venous Catheter in the Subclavian Artery

Subclavian artery (SCA) injuries associated with central venous catheter (CVC) insertion are uncommon yet lethal complications that typically require surgical treatment. This case report presents the case of a 94-year-old man with an iatrogenic right SCA injury resulting from a misplaced CVC. Computed tomography revealed the catheter piercing the right internal jugular vein to enter the right SCA and then reaching the aortic arch. Emergent endovascular treatment was performed, and a 13-mm × 50-mm self-expanding Viabahn stent graft (W.L. Gore & Associates, Flagstaff, AZ, USA) was placed via the right brachial artery. The misplaced catheter was successfully removed under simultaneous postdeployment balloon dilatation. This case highlights the utility of the Viabahn stent graft for iatrogenic right SCA injury caused by a misplaced CVC and presents some insights and tips for a safer procedure.

Endovascular treatment of aortoiliac aneurysms: From intentional occlusion of the internal iliac artery to branch iliac stent graft

Approximately 20%-40% of patients with abdominal aortic aneurysms can have unilateral or bilateral iliac artery aneurysms and/or ectasia. This influences and compromises the distal sealing zone during endovascular aneurysm repair. There are a few endovascular techniques that are used to treat these types of aneurysms, including intentional occlusion/over-stenting of the internal iliac artery on one or both sides, the "bell-bottom" technique, and the more recent method of using an iliac branch stent graft. In some cases, other options include the "snorkel and sandwich" technique and hybrid interventions. Pelvic ischemia, represented as buttock claudication, has been reported in 16%-55% of cases; this is followed by impotence, which has been described in 10%-17% of cases following internal iliac artery occlusion. The bellbottom technique can be used for a common iliac artery up to 24 mm in diameter given that the largest diameter of the stent graft is 28 mm. There is a paucity of data and evidence regarding the "snorkel and sandwich" technique, which can be used in a few clinical scenarios. The hybrid intervention is comprised of a surgical operation, and is not purely endovascular. The newest branch stent graft technology enables preservation of the anterograde flow of important side branches. Technical success with the newest technique ranges from 85%-96.3%, and in some small series, technical success is 100%. Buttock claudication was reported in up to 4% of patients treated with a branch stent graft at 5-year follow-up. Mid- and short-term follow-up results showed branch patency of up to 88% during the 5-6-year period. Furthermore, branch graft occlusion is a potential complication, and it has been described to occur in 1.2%-11% of cases. Iliac branch stent graft placement represents a further development in endovascular medicine, and it has a high technical success rate without serious complications.

Which Offers the Best? Stent Graft or Bare Metal Stent for Endovascular Treatment of Aortoiliac Disease

Background: In the present study, it was aimed to compare the stent grafts and bare-metal stents in terms of post-procedural patency, clinical recovery and complications in the subjects with symptomatic aorto-iliac arterial disease. Methods: A total of 79 subjects with symptomatic aorto-iliac arterial disease treated with endovascular methods were included in the present study. Forty three subjects received self-expendable bare metal stent (ev3 Protégé stent system, Endovascular Inc., Plymouth, Minnesota, USA) and 36 subjects received PTFE-covered stent graft (Fluency Plus Stent Graft, Bard Peripheral Vascular, Tempe, Arizona). The subjects were compared after and at Months 1, 6, and 12 following the procedure in terms of Rutherford’s classification, ankle-arm index (AAI), patency rates, and complications. Results: The subjects receiving bare metal stent and stent graft for aorto-iliac arterial disease were followed for averagely 15 months. For the subjects receiving bare metal stent, primary patency rates at months 1, 6, and 12 were 98%, 81%, and 70%, respectively, while secondary patency rate at month 12 was found to be 84%. For the group of stent graft, primary patency rates were found as 97%, 97%, and 92%, respectively and secondary patency rate at month 12 was found to be 94%. Stent grafts were applied at the same time in 2 patients who had metal bare metal because the rupture occurred during the procedure. In the comparison between two groups, the group of stent graft was found to be statistically superior to the other in terms of patency, clinical and post-procedural complications. Conclusion: In conclusion, it was found that the stent grafts were superior to the bare metal stents in terms of patency and complication rates in the subjects with symptomatic aortoiliac disease.

Hybrid Procedure Utilizing Stent Grafts to Stabilize Distal Flaps after Common and Superficial Femoral Endarterectomy

Background: Endarterectomy has long been the standard for common femoral artery (CFA) occlusive disease. Hybrid procedures utilizing endovascular and open techniques have recently been used for revascularization. The purpose of this study was to evaluate the effectiveness of the use of a stent graft to stabilize the distal flap and prevent further dissection after extensive endarterectomy. Methods: All patients from Monmouth Medical Center in Long Branch, NJ from September 2008 to March 2013 who underwent an extensive common and superficial femoral (SFA) endarterectomy combined with the use of a Viabahn (Gore Medical) stent graft to stabilize the distal flap were included in the study. These stents were deployed in the proximal SFA after extensive endarterectomy, under direct visualization, without the aid of fluoroscopy. Due to the location in the SFA, these flaps were not amenable to suture tacking. Results: Fifteen patients met these criteria and were included in our study. Twelve patients underwent femoral endarterectomy for severe claudication and three patients for limb salvage. Technical success was achieved in all 15 patients. Five patients also had stents placed proximally to increase inflow and one patient had an additional stent placed distally to improve outflow. There were no intraoperative or postoperative complications. Conclusion: Stent graft placement allows a more extensive endarterectomy to be performed by stabilizing the distal flap allowing a safe transition into the true lumen that is not possible with suture tacking.

Endovascular stent graft repair of abdominal aortic aneurysms:Current status and future directions

Endovascular stent graft repair of abdominal aortic aneurysm(AAA)has undergone rapid developments since it was introduced in the early 1990s.Two main types of aortic stent grafts have been developed and are currently being used in clinical practice to deal with patients with complicated or unsuitable aneurysm necks,namely,suprarenal and fenestrated stent grafts.Helical computed tomography angiography has been widely recognized as the method of choice for both pre-operative planning and post-operative followup of endovascular repair(EVAR).In addition to 2D axial images,a number of 2D and 3D reconstructions are generated to provide additional information about imaging of the stent grafts in relation to the aortic aneurysm diameter and extent,encroachment of stent wires to the renal artery ostium and position of the fenestrated vessel stents.The purpose of this article is to provide an overview of applications of EVAR of AAA and diagnostic applications of 2D and 3D image visualizations in the assessment of treatment outcomes of EVAR.Interference of stent wires with renal blood flow from the hemodynamic point of view will also be discussed,and future directions explored.

Evaluation of embedded modular branched stent graft in treating aortic arch aneurysm using imaging-based computational flow analysis

Embedded modular branched stent graft(EMBSG)was a new option for aortic arch aneurysm.However,the therapeutic effect of this innovative stenting technique has not been fully assessed.Computational fluid dynamics and three-dimensional structural analyses were performed on three patients(Patient Ⅰ,Patient Ⅱ and Patient Ⅲ)with aortic arch aneurysm,both before and after EMBSG implantation.Patient-specific alterations from preoperative to postoperative were analyzed via morphological and functional metrics.Patient Ⅰ and Patient Ⅱ showed notable curvature changes and area reduction after intervention procedure.Three patients showed an increase in flow velocity after EMBSG implantation,while the pressure drop from ascending aorta to the aortic arch was remarkable in Patient I and Patient Ⅱ with the value of 7.09mmHg,and 10.95mmHg,respectively.Patient I and Patient Ⅱ also showed elevated time-averaged wall shear stress(TAWSS)in the stenting region,while Patient Ⅲ showed a trivial change in TAWSS after intervention procedure.Three patients showed low relative residence time after EMBSG insertion.The short-term results of EMBSG in treating aortic arch aneurysm were promising.Hemodynamic parameters have the potential to assist in the outcome evaluation and might be used to guide the stent graft design and wise selection,thereby improving the long-term therapeutic effect in managing complex vascular disease.

Management of adults with coarctation of aorta

Coarctation of the aorta(CoA)is a relatively common congenital cardiac defect often causing few symptoms and therefore can be challenging to diagnose.The hallmark finding on physical examination is upper extremity hypertension,and for this reason,CoA should be considered in any young hypertensive patient,justifying measurement of lower extremity blood pressure at least once in these individuals.The presence of a significant pressure gradient between the arms and legs is highly suggestive of the diagnosis.Early diagnosis and treatment are important as long-term data consistently demonstrate that patients with CoA have a reduced life expectancy and increased risk of cardiovascular complications.Surgical repair has traditionally been the mainstay of therapy for correction,although advances in endovascular technology with covered stents or stent grafts permit nonsurgical approaches for the management of older children and adults with native CoA and complications.Persistent hypertension and vascular dysfunction can lead to an increased risk of coronary disease,which,remains the greatest cause of long-term mortality.Thus,blood pressure control and periodic reassessment with transthoracic echocardiography and threedimensional imaging(computed tomography or cardiac magnetic resonance)for should be performed regularly as cardiovascular complications may occur decades after the intervention.

An endoluminal aortic prosthesis infection presenting as pneumoaorta and aortoduodenal fistula

Herein, we present a case of pneumoaorta and aorto-duodenal fistula (ADF) caused by an endoluminal aortic prosthesis infection. An 82-year-old man underwent endovascular aneurysm repair with a stent graft to exclude a 5.1-cm abdominal aortic aneurysm. Three months after the index procedure, the patient was taken to the emergency department at a medical university hospital. He presented with a 2-d history of bloody diarrhea. An endoluminal aortic stent graft infection was diagnosed, and an ADF was identified. The patient died of septic shock despite emergency surgery and intensive care. When encountered, stent graft infections require appropriate antibiotics and graft explantation.The diagnosis of an ADF is important, and surgery remains the most effective management if septic shock presents despite conservative treatment.

Modified Double-Fenestrated Stent Graft for Branched Thoracic Endovascular Aortic Repair of an Irregular Aortic Arch Aneurysm:A Case Report

A 43-year-old male was admitted to General Hospital of Northern Theater Command with exacerbation of chest pain for 10 d.Computed tomographic angiography(CTA)showed an irregular aortic arch aneurysm involving the left subclavian artery(LSA),with penetrating aortic ulcer and intramural hematoma.A modified fenestrated thoracic endovascular aortic repair(TEVAR)technique was performed successfully.Follow-up CTA showed that stent grafts were well-apposed,without endoleaks,migration,or branch artery occlusion,and the hematoma was almost completely absorbed.In this case,precise fenestrations were created by measurements based on three-dimensional CT reconstruction and angiography.Furthermore,the physician chose an LSA approach to catch the guide wire and deployed branched stent grafts,considering the oblique direction of this branch and the small size of the fenestration.This case shows that pre-fenestrated and inner bare stent enhancing TEVAR is a safe and feasible technique for repair of complicated aortic arch aneurysm.

Total endovascular repair of an intraoperative stent-graft deployed in the false lumen of Stanford type A aortic dissection: A case report

BACKGROUND A 46-year-old male underwent ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection in 2016.However,an intraoperative stent-graft was deployed in the false lumen inadvertently.This caused severe iatrogenic thoracic and abdominal aortic dissection,and the dissection involved many visceral arteries.CASE SUMMARY The patient had pain in the chest and back for 1 mo.A computed tomography scan showed that the patient had secondary thoracic and abdominal aortic dissection.The ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection were performed 2 years prior.An intraoperative stent-graft was deployed in the false lumen.Endovascular aneurysm repair was performed to address this intractable situation.An occluder was used to occlude the proximal end of the true lumen,and a covered stent was used to direct blood flow back to the true lumen.A three-dimensional printing technique was used in this operation to guide prefenestration.The computed tomography scan at the 1stmo after surgery showed that the thoracic and abdominal aortic dissection was repaired,with all visceral arteries remaining patent.The patient did not develop renal failure or neurological complications after surgery.CONCLUSION The total endovascular repair for false lumen stent-graft implantation was feasible and minimally invasive.Our procedures provided a new solution for stent-graft deployed in the false lumen,and other departments may be inspired by this case when they need to rescue a disastrous stent implantation.

Experience with Thoracic Aortic Stent-Grafting at the Royal Brisbane and Women’s Hospital: Outcomes from the First Decade

Objectives: To describe thoracic endovascular aortic repair (TEVAR) outcomes at the Royal Brisbane and Women’s Hospital between 2001-2010. Design: Prospective cohort study. Results: We successfully treated 95 of 97 patients for a 98% procedural success rate. Of the treated patients, 68 (72%) were males and mean age was 61 ± 17 years. Average follow up was 3.6 ± 2.0 years. Pathologies treated were: dissection (n = 35), aneurysmal disease (n = 32), traumatic disease (n = 19), coarctation (n = 5) and miscellaneous (n = 4). There was one peri-procedural myocardial infarction. Renal complications occurred in 7 patients (3 with doubling creatinine and 4 requiring temporary renal replacement therapy). Stroke occurred in 2 patients and paresis in 2 patients (permanent in one). Six patients died during index hospitalization and 17 deaths occurred during follow-up, 2 of which were confirmed secondary to aortic pathology. Age (HR 1.08 per year, p < 0.01) and ASA class (HR 2.2 per class, p = 0.02) were independently associated with mortality. There were 25 re-interventions in 22 patients. Eighteen of these re-interventions in 16 patients were related to the management of complications of TEVAR of which 13 were for endoleaks;eight type I, four type II, one type III. Conclusion: TEVAR can be used to treat thoracic aortic pathology but questions remain regarding long-term durability.