Use Of Endovascular Stent Grafts Research Articles

Popliteal artery aneurysms treatments: early midterm results of the use of endovascular stent grafts

Background/aimPopliteal artery aneurysms (PAAs) are abnormal bulgings, which account for 70% of all peripheral artery aneurysms. They are usually asymptomatic. In this study, we present our long-term results of endovascular stent grafts in the treatment of PAA in the light of literature data.Material and methodsA total of 63 legs of 63 patients with PAA, who were treated with endovascular techniques in our clinic between July 2010 and July 2019, were retrospectively analyzed. All patients underwent color Doppler ultrasound (DUS), magnetic resonance angiography (MRA), or computed tomography angiography (CTA) to identify the diameter and length of PAAs, vessel tortuosity, the presence and degree of thrombus, and diameter in the healthy landing zone and to visualize tibioperoneal vascular structures. A Viabahn stent graft was inserted in all patients.Results57 patients (90.5%) were males with a mean age of 76.35 ± 7 years. 24 patients (38.1%) were symptomatic, while 11 patients (17.5%) had a concomitant abdominal aortic aneurysm (AAA). The mean follow-up period was 46.05 ± 25.01 months. The primary patency rate was 79.3%. A graft thrombosis was observed in 13 patients (20.6%) during a mean follow-up period of 8.31 ± 5.91 months. The number of distal arteries was significantly lower in the patients with thrombosis than those without.ConclusionsEndovascular treatment of PAA using stentgrafts is safe in selected cases. However, it is reasonable to avoid endovascular treatment due to an increased risk for thrombosis in patients with a low number of patent distal arteries or impaired distal flow.

Directional Control for Precise Deployment of Endovascular Aneurysm Repair and Thoracic Endovascular Aortic Repair in Angulated Anatomy

Endovascular stent graft repair of aortic aneurysms has become the standard in most centers. Several anatomic constraints still prevent or compromise the use of this technology. Angulated infrarenal aortic necks or steep aortic arches may result in erratic stent graft deployment with inadvertent branch vessel coverage, inadequate lesion coverage, or bird beaking. We have developed a technique using off-the-shelf equipment to precisely control the deployment of stent grafts in challenging landing zones. Two patients with challenging proximal landing zones were treated by this technique. The first patient, a 72-year-old man, was treated with a Gore Excluder device (W. L. Gore & Associates, Flagstaff, Ariz) for a 5.6-cm infrarenal aortic aneurysm with an angulated neck. A standard J wire was passed through the device, captured with an endosnare, and removed through a Destino sheath (Oscor, Palm Harbor, Fla) in the contralateral groin. The through-and-through wire and sheath allowed the precise deflection of the device along the angulated neck. The device was deployed while deflected. The remainder of the case was unremarkable. The second patient was an 84-year-old man who developed a descending thoracic aortic intramural hematoma with acute enlargement and pseudoaneurysm in the setting of type III aortic arch. In the operating room, two GORE CTAG thoracic stent grafts were built up from the celiac into the proximal descending thoracic aorta. A final proximal stent graft was advanced into approximate position. Left brachial access was established, and a J wire was brought through and through from the stent graft into a 5F MPA catheter in the left brachial sheath. Through a combination of wire traction and forward force on the MPA catheter, the device was precisely positioned onto the lesser curve. The graft was deployed orthogonally at the level of the left carotid. A left subclavian snorkel was planned preoperatively and was placed. In both cases, technical success was attained. Follow-up imaging at 6 weeks in each case demonstrated continuous wall apposition and no endoleak. Anatomic constraints have limited or complicated the use of endovascular stent grafts for some aortic disease. The use of a through-and-through flexible wire and a stiff catheter or sheath allows precise placement in these challenging landing zones.

Contemporary endovascular treatment of type B aortic dissection in China.

Endovascular stent-grafts have been used in China to treat type B aortic dissection since 1999, and there is a plethora of cohort studies in the contemporary literature. The aim of this review was to analyse the published results of endovascular treatment for type B aortic dissection in China. A systematic literature review of all published literature from January 1999 to October 2014 on endovascular treatment of type B aortic dissection in China was undertaken using PubMed, Medline, and the Chinese National Knowledge Infrastructure databases. Seventy papers were retrieved (4 English, 66 Chinese) with a total of 4208 patients; 3396 (80.7%) were male, and the mean age ranged from 43 to 65 years. Procedural success was reported in 99.4% ± 1.7%. Complications were reported in 14.6% ± 11.1%, with major complications in 1.7% ± 2.9%, and the most devastating neurologic complications in 1.1% ± 2.2% (stroke 0.9% ± 2.4%, paraplegia 1.5% ± 0.7%). Postoperative endoleak occurred in 8.1% ± 7.6%. The 30-day postoperative mortality was 2.4% ± 3.3%. During follow-up, false-lumen thrombosis occurred in 92.1% ± 11.7%. Reintervention was performed in 1.3% ± 3.3%. The incidence of proximal and distal stent-graft-induced new entry was 0.5% ± 1.3% and 0.9% ± 2.7%, respectively, with endoleak in 2.7% ± 4.4% and mortality of 2.2% ± 3.2%. Current evidence suggests that use of endovascular stent-grafts for type B aortic dissection in China is feasible and safe with low rates of perioperative complications and short-term mortality. However, a standardised reporting system and long-term follow-up data are lacking.

Percutaneous Balloon-Expandable Covered Stent Implantation for Treatment of Traumatic Aortic Injury in Children and Adolescents

Surgical treatment of pediatric acute traumatic aortic injury (TAI) after blunt chest trauma is standard of care. Use of endovascular stent grafts for treatment of TAI in adults is common but has important limitations in children. We sought to describe the use of balloon-expandable covered endovascular stents for treatment of TAI in children and adolescents. Participants of the multicenter Coarctation of the Aorta Stent Trial (COAST) had access to investigational large-diameter, balloon-expandable, covered stents (covered Cheatham-platinum stents; NuMed, Inc., Hopkinton, New York) on an emergency-use basis. From 2008 through 2011, 6 covered stents were implanted in 4 patients at 3 COAST centers for treatment of TAI. Median patient age was 13.5 years (range 11 to 14) and weight was 58 kg (40 to 130). All patients sustained severe extracardiac injuries that were judged to preclude safe open surgical repair of TAI. Median aortic isthmus and stent implantation balloon diameters were 16.4 mm (13.2 to 19) and 19 mm (16 to 20), respectively. Stent implantation was technically successful in all attempts. Complete exclusion of aortic wall injury was achieved in all cases. There were no access site complications. At a median follow-up of 24 months, there was 1 early death (related to underlying head trauma) and 1 patient with recurrent aortic aneurysm who required additional stent implantation. In conclusion, balloon-expandable covered-stent implantation for treatment of pediatric TAI after blunt trauma is generally safe and effective. Availability of this equipment may alter the standard approach to treatment of pediatric TAI.

New method for improved calculations of unsteady complex flows in large arteries

Using an improved computational fluid dynamics (CFD) method developed for highly unsteady three-dimensional flows, numerical simulations for oscillating flow cycles and detailed unsteady simulations of the flow and forces on the aortic vessels at the iliac bifurcation, for both healthy and diseased patients, are analyzed. Improvements in computational efficiency and acceleration in convergence are achieved by calculating both an unsteady pressure gradient which is due to fluid acceleration and a good global pressure field correction based on mass flow for the pressure Poisson equation. Applications of the enhanced method to oscillatory flow in curved pipes yield an order of magnitude increase in speed and efficiency, thus allowing the study of more complex flow problems such as flow through the mammalian abdominal aorta at the iliac arteries bifurcation.To analyze the large forces which can exist on stent graft of patients with abdominal aortic aneurysm (AAA) disease, a complete derivation of the force equations is presented. The accelerated numerical algorithm and the force equations derived are used to calculate flow and forces for two individuals whose geometry is obtained from CT data and whose respective blood pressure measurements are obtained experimentally. Although the use of endovascular stent grafts in diseased patients can alter vessel geometries, the physical characteristics of stents are still very different when compared to native blood vessels of healthy subjects. The geometry for the AAA stent graph patient studied in this investigation induced flows that resulted in large forces that are primarily caused by the blood pressure. These forces are also directly related to the flow cross-sectional area and the angle of the iliac arteries relative to the main descending aorta. Furthermore, the fluid flow is significantly disturbed in the diseased patient with large flow recirculation and stagnant regions which are not present for healthy subjects.

Endovascular treatment of supra‐celiac aortic pseudoaneurysms following liver transplantation

The development of supra-celiac pseudoaneurysms following aorto-hepatic reconstruction during liver transplantation represents a major and surgically challenging complication. However, the use of endovascular stent grafts for the exclusion of aortic aneurysms is now a standard procedure with low morbidity and mortality. We demonstrate the successful endovascular repair of three cases of supra-celiac pseudoaneurysms, which developed after liver transplantation. A 40-yr-old woman, a 61-yr-old man, and a 45-yr-old woman underwent liver transplantation for end-stage liver disease. Between three months and five yr after the transplantation the patients developed large supra-celiac pseudoaneurysms leading to thrombosis of the hepatic artery and biliary complications. The stent graft implantation was uneventful, one endoleak Type I occluded spontaneously. There were no intervention-related complications. Unfortunately, one patient died one month after the procedure due to progressive liver failure and one died after five months due to multiple organ failure. One patient is still alive and in good condition.

Endovascular Repair of Para-Anastomotic Aortoiliac Aneurysms

The purpose of this study is to evaluate the use of endovascular stent grafts in the treatment of para-anastomotic aneurysms (PAAs) as an alternative to high-risk open surgical repair. We identified all patients with previous open aortic aneurysm repair who underwent infrarenal endovascular aneurysm repair (EVAR) at our institution from June 1998 to April 2007. Patient demographics, previous surgery, and operative complications were recorded. One hundred forty-eight patients underwent EVAR during the study period and 11 patients had previous aortic surgery. Of these 11 redo patients, the mean age was 62 years at initial surgery and 71 years at EVAR. All patients were male. Initial open repair was for rupture in five (45%) patients. The average time between initial and subsequent reintervention was 9 years. All patients were ASA Grade III or IV. Fifty-five percent of the PAAs involved the iliac arteries, 36% the abdominal aorta, and 9% were aortoiliac. Ten patients had endovascular stent-grafts inserted electively, and one patient presented with a contained leak. Aorto-uni-iliac stent-grafts were deployed in seven patients, and bifurcated stent-grafts in four patients. A 100% successful deployment rate was achieved. Perioperative mortality was not seen and one patient needed surgical reintervention to correct an endoleak. Endovascular repair of PAAs is safe and feasible. It is a suitable alternative and has probably now become the treatment of choice in the management of PAAs.

Implication of Thoracic Aortic Stent-Graft Conformability on Clinical Outcomes

Endovascular management concepts have recently emerged as valuable treatment options for both simple and complex disorders involving both the distal arch and descending thoracic aorta. With growing use of endovascular stent-grafts the technique has generated broad interest. Nevertheless, an ideal device for different thoracic aortic conditions is not available yet. After initially using the first-generation or “home-made” thoracic stent-grafts with its relative rigidity and considerable diameter of the delivery system, recent advances have generated more flexible and conformable second-and third-generation stent-grafts. Nonetheless, challenges of providing optimal conformability and better fixation in the aortic arch and thoracic aorta are substantial, given the spiralling motion of the thoracic aorta with each ventricular contraction. Ultimately, the capacity of thoracic stent-graft to appose tightly to the aortic wall not only ensures effective sealing and fixation, but also avoids endoleaks and migration, graft stability and thus overall successful repair with aortic remodeling. Conformability is therefore the combined effect of apposition to the thoracic aortic anatomy, and kink-resistant flexibility of the stent-graft

Acute Traumatic Aortic Tear: Open Versus Stent-graft Repair

Acute traumatic aortic tear (ATAT) is the second most common cause of deaths in trauma patients (about 8,000 deaths/year in the USA). Due to circumferential aortic disruption, up to 90% die at the scene. Responsible trauma mechanisms are: penetrating (gunshot/stab wounds), iatrogenic (interventional catheterization) and, most frequently, blunt chest trauma (high-speed motor vehicles, falls from heights, crushes, explosions) resulting in injury at the aortic isthmus region (loco typico, about 90%). Severe multiple system injuries (polytrauma), especially to intracranial and intraabdominal organs, are characteristic and prognostically predicitive. Immediate transthoracic open repair of ATAT has a mortality risk of 8% to 33% and paraplegia risk of 2% to 26%. Contrast enhanced CT scan has replaced the classical angiography as the diagnostic tool of choice. Patients with life-threatening multisystem injuries are scheduled for delayed repair after initial stabilization. Currently, the use of endovascular stent-grafts (EVAR) is being investigated. Our personal series confirms that EVAR for ATAT is a viable alternative to open repair while minimizing the morbidity and mortality of the open procedure and having a limited impact on trauma destabilization. The assessment of long-term durability of EVAR is one of the key issues to consider EVAR as the first choice of treatment.

Endovascular Stent Grafting of Thoracic Aortic Aneurysms

The use of endovascular stent grafts is a leading technological advancement in the treatment of thoracic aortic aneurysms, and is being trialed in the United States as an alternative to medical management and traditional surgical repair. Aortic stent grafts, initially used only for abdominal aortic aneurysms, have been used for over 10 years in Europe and are currently under United States Food and Drug Administration investigation for the treatment of chronic and acute aortic aneurysms. Diseases of the thoracic aorta are often present in high-risk individuals, and, as a result, there is a high morbidity and mortality rate associated with both medical and surgical management of these patients. The development and refinement of endovascular approaches have the potential to decrease the need for traditional surgical repair, especially in high-risk populations such as the elderly and those with multiple comorbidities. Endovascular technology for thoracic repair has only been used in Europe for the last 10 years, with no long-term outcomes available; however, preliminary research demonstrates favorable early and midterm outcomes showing that endovascular stent graft placement to exclude the dilated, dissected, or ruptured aorta is both technically feasible and safe for patients. The article highlights the historical perspective of endovascular stent grafting as well as a description of patient selection, the operative procedure, benefits, risks, and unresolved issues pertaining to the procedure. A brief review of aneurysm and dissection pathophysiology and management is provided, as well as postoperative management for acute care nurses and recommendations for clinical practice.

To stent or not to stent aortic dissection: good news for a chosen few, but who?

This editorial refers to ‘Endovascular stent-graft treatment of aortic dissection: determinants of post-interventional outcome’† by H. Eggebrecht et al. , on page 489 Eggebrecht and colleagues,1 report their single centre experience with the interventional use of endovascular stent-grafts in the setting of both chronic and acute thoracic aortic dissection, referred to or recruited by a group of cardiologists and followed up for between 1 and 57 months. The group at the West German Heart Centre in Essen confirm the reported feasibility and report a high technical success rate for endovascular stent-grafting in the hands of skilled practitioners,2–5 associated, however, with an 11% non-fatal periprocedural complication rate. Interestingly, though not surprisingly, multivariate analysis of their 38 cases revealed only parameters such as advanced age and poor health status due to comorbidities, to be predictors of mortality after successful stent-graft placement, while the mixed bag of ‘accepted indications’ for stent-graft placement, such as contained rupture, refractory hypertension from renal malperfusion, branch vessel compromise and progressive enlargement of more than 1 cm/year of a patent false lumen,5–7 were not among those predictive variables with significant impact. The reported results, although derived from a limited number of patients, may shed new light on an ongoing conflict which closely accompanies any new and potentially helpful interventional technology, … *Corresponding author. Tel: +49 381 494 77 00; fax: +49 381 494 77 02. E-mail address : christoph.nienaber{at}med.uni-rostock.de

Endovascular Treatment of a MRSA Infected Left External Iliac Artery Pseudoaneurysm

Infected aneurysms and pseudoaneurysms pose a therapeutic conundrum. Conventional practice avoids the placement of foreign material in infected sites, however, there are reports of the use of endovascular stent-grafts in this situation. We describe the successful immediate and 1 year outcome of emergency endovascular stent-grafting of a methicillin resistant Staphylococcus aureus (MRSA) infected pseudoaneurysm.

Management Trends and Early Mortality Rates for Acute Type B Aortic Dissection: A 10-Year Single-Institution Experience

This study was undertaken to assess trends in management over time and to determine predictors of early mortality for acute type B aortic dissection. Fifty-three consecutive patients with acute type B aortic dissection over a 10-year period were reviewed. Baseline demographics as well as in-hospital data regarding symptoms, type of initial management, surgical indications, type of surgical intervention, and early mortality rates were collected. Independent predictors of early mortality were determined by logistic regression. Forty-one of 53 (77.4%) patients were initially managed medically with a total of 26 (49.1%) ultimately undergoing surgical repair during hospitalization. Crude early mortality was 30.8% in the surgical group vs. 14.8% in the medical group (p = 0.20). Improvements in early mortality were observed over time for surgery (58.3%, first half vs. 7.1%, second half; p = 0.019) and medical therapy (21.4%, first half vs. 7.7%, second half; p = 0.64). Early mortality was 50% in 16 patients having open aortic surgery vs. 0% in 10 patients undergoing endovascular stent graft repair (p < 0.005). Independent predictors of early mortality included only renal dysfunction (odds ratio [OR] 7.39), aortic rupture (OR 8.72), and date of admission during the study period (OR 0.712). Despite improvements over time in early mortality that appear associated with the increasing use of endovascular stent grafts, patient-specific factors are still the most important independent predictors of early mortality in acute type B aortic dissection.

A Case Report of Intentional Occlusion of an Aberrant Right Subclavian Artery during Endovascular Stent-graft Repair of a Descending Aortic Aneurysm

The use of endovascular stentgrafts in the descending thoracic aorta was first described by Parodi in 1994. We describe the first case of intentional occlusion of an aberrant right subclavian artery with an endoluminal stentgraft in the treatment of a descending thoracic aortic aneurysm (TAA) without the need for a subclavian revascularisation procedure. In view of the reported prevalence of 0.4–2% of arteria lusoria, and the increasing use of endovascular grafting, we feel that is a significant clinical entity.

Endovascular Vein Graft for the Treatment of Popliteal Pseudoaneurysm

Recent reports have documented the use of covered stents for the treatment of traumatic injuries to the vascular system. We report the first use of an autologous vein-covered Palmaz stent for the treatment of a popliteal artery pseudoaneurysm. A 5-foot-2-inch, 320-pound woman was referred to the authors' institution with new onset of pain and ecchymosis in the popliteal fossa while on Coumadin therapy for treatment of a deep venous thrombosis. She had undergone left total knee replacement 13 months previously. A contrast computed tomography (CT) scan confirmed an 8-cm aneurysm behind the knee. The patient was offered endovascular treatment of this aneurysm as an alternative to bypass surgery. Intraoperative arteriography was performed through a superficial femoral artery cutdown and demonstrated a large popliteal pseudoaneurysm. A 2-cm Palmaz stent was attached to a 6-mm-wide-by-2-cm-long side branch of greater saphenous vein and was used to occlude the neck of the pseudoaneurysm. Completion arteriogram confirmed exclusion of the pseudoaneurysm, and the patient regained a dorsalis pedis pulse after the procedure. Patency at 12 months was confirmed by duplex examination, with the presence of a normal ankle-brachial index (ABI) and normal velocities. The use of endovascular stent grafts made with autogenous tissue offers an attractive alternative to open surgical procedures in technically complex cases. This case demonstrates that a combined open surgical and endovascular approach can be successfully used for the management of traumatic injuries to the popliteal artery. Further investigation will be necessary to evaluate the long-term efficacy of this approach in managing popliteal artery injuries.

Endovascular Stent-Grafts for Aneurysms of the Femoral and Popliteal Arteries

Our objective was to investigate the preliminary use of endovascular stent-grafts for the treatment of femoropopliteal artery aneurysm. Ten patients with an aneurysm of the femoropopliteal artery referred for endovascular treatment were investigated. The series consisted of patients with a true aneurysm of the superficial femoral artery (n = 2); a true aneurysm of the popliteal artery (n = 4); an aneurysmal dilatation of a Biograft bypass (n = 2); a false aneurysm of the superficial femoral aneurysm (n = 1); and a false aneurysm of a composite bypass (n = 1). In 8 of the 10 patients the stent-graft was composed of one or more Palmaz stents sutured to an ePTFE tube graft; in the other 2 patients a venous covering was used in combination with Palmaz stents. The procedure was guided by angiography and intravascular ultrasound. The results of our investigation showed that endovascular stent-grafting of aneurysms of the femoropopliteal artery is a feasible but experimental technique that should be restricted to a selected group of patients.

Mycotic Aneurysms of the Thoracic Aorta: Repair with Use of Endovascular Stent-Grafts

Standard therapy of mycotic aneurysms in the descending aorta consists of thoracotomy and in situ graft placement or extraanatomic bypass. The alternative use of endovascular stent-grafts was evaluated for management of infected aneurysms of the thoracic aorta. In a retrospective analysis during a 5-year period, 112 patients underwent stent-graft placement for thoracic aortic aneurysms. Three patients (mean age, 68.6; range, 64-70 years) had mycotic thoracic aneurysms. Stent-grafts were constructed from Z stents covered with polyester fabric and were delivered remotely through a catheter under fluoroscopic guidance. Complete thrombosis of the mycotic aneurysms was achieved in all patients. One patient required a second separate stent-graft placement procedure because of migration of the initial device; the second patient underwent surgical repair of a ruptured mycotic abdominal aortic aneurysm followed immediately by stent-graft placement for a chronic mycotic thoracic aneurysm; a third patient underwent repair of two infected false aneurysms secondary to complete rupture of a surgical interposition graft. There were no complications of persistent bacteremia despite placement of the stent-graft device at the site of primary infection, reinfection, delayed rupture, paraplegia, distal emboli, or surgical conversion. One patient died of cardiac arrest at 25 months; there were no perioperative deaths (< or = 30 days). The remaining two patients were alive and well at median follow-up of 24 months (range, 4-25 months). Endovascular stent-grafts combined with antibiotic therapy may be an alternative to conventional thoracotomy in managing mycotic aneurysms of the descending thoracic aorta.

Acute Rupture of the Descending Thoracic Aorta: Repair with Use of Endovascular Stent-Grafts

To describe the use of endovascular stent-grafts to treat acute ruptures of the descending thoracic aorta as an alternative to surgery in high-risk patients. From July 1992 to August 1996, 95 patients underwent stent-grafting of the descending thoracic aorta for a variety of lesions. Of these, 11 patients with acute (< or = 7 days) rupture from aneurysms (n = 8) or trauma (n = 3) underwent repair with use of endovascular stent-grafts. Rupture was confirmed with preoperative imaging studies and occurred in the mediastinum (n = 9), the pleural space (n = 1), or the lung (n = 1). All patients were considered high surgical risk due to generalized cardiopulmonary disease and/or previous thoracotomies. Stent-grafts were constructed from Z stents covered with polyester fabric and delivered through a catheter under fluoroscopic control from a remote access site. Stent-graft deployment was successful in all patients. There were no complications of perigraft leak, stent migration, paraplegia, or intraoperative death. Two patients died in the follow-up period: one of ventricular perforation during unrelated thoracic surgery for tumor resection (day 1) and one of cardiac arrest (day 28). All others are alive (mean follow-up, 15.1 months). For acute rupture of the thoracic aorta, endovascular stent-graft repair is technically feasible and may be a therapeutic alternative to a surgical interposition graft in patients considered high risk for conventional thoracotomy. Long-term studies are necessary to determine the role of stent-grafts in preventing future aortic rupture.