Endovascular stent graft selection for the treatment of abdominal aortic aneurysms

Minimally invasive endovascular techniques for the treatment of abdominal aortic aneurysms (AAA) have significantly reduced the morbidity of these procedures as compared with standard surgical repair. In addition, patients with extensive comorbid medical illnesses in whom standard operative repair is contra-indicated, may be successfully treated using endovascular means. A variety of endovascular stent grafts are currently being used clinically for endovascular AAA repair. The characteristics of these stent grafts vary significantly. In selecting the specific stent graft to be used for endovascular AAA repair, these specific characteristics must be considered particularly with regard to the individual patient's anatomic and physiologic characteristics. The United States Food and Drug Administration (FDA) has approved 4 endovascular stent grafts for the treatment of AAA: the Medtronic AneuRx, the W. L. Gore Excluder, the Cook Zenith and the Guidant Ancure. The Zenith graft received approval for marketing in 2003 and has gained relatively wide usage, in part due to its ability to treat aneurysms with relatively large diameter implantations zones. Also in 2003 the Guidant Corporation withdrew the Ancure graft from marketing and distribution. Enrollment has also been recently completed for the phase II FDA trials of the Medtronic Talent graft and the Cordis Fortron graft. These devices have been approved for use in the European Union and are awaiting FDA panel meeting in the United States. Comparative analysis of several of the available stent grafts has been performed. Results have varied with regard to the need for secondary interventions, aneurysm sac size reduction and the occurrence of continued perfusion of the aneurysm sac. Several significant advances have also occurred recently in stent graft research and development. Of particular significance has been the initiation of the phase I trial of the Trivascular Enovus graft. Deployment of the Trivascular graft may be accomplished through a delivery system that is considerably reduced in profile. The potential for percutaneous application of the graft may be available in the future. The indications for use of endovascular grafts as compared to standard open surgery have not yet been fully defined. Endovascular stent grafts in current use have limitations and their use must be tempered accordingly, until their long-term effectiveness is more completely evaluated. This article describes the general principles of use for endovascular devices for the repair of AAAs. It details the features and results for the devices in current use and highlights the factors that influence the selection of specific stent graft types.     

Endovascular stent graft repair of abdominal and thoracic aortic aneurysms: a ten-year experience with 817 patients

OBJECTIVE: On November 23, 1992, the first endovascular stent graft (ESG) repair of an aortic aneurysm was performed in North America. Following the treatment of this patient, we have continued to evaluate ESG over the past 10 years in the treatment of 817 patients. SUMMARY AND BACKGROUND DATA: Abdominal (AAA) or thoracic (TAA) aortic aneurysms are a significant health concern traditionally treated by open surgical repair. ESG therapy may offer protection from aneurysm rupture with a reduction in procedure morbidity and mortality. METHODS: Over a 10-year period, 817 patients were treated with ESGs for AAA (723) or TAA (94). Patients received 1 of 12 different stent graft devices. Technical and clinical success of ESGs was reviewed, and the incidence of procedure-related complications was analyzed. RESULTS: The mean age was 74.3 years (range, 25-95 years); 678 patients (83%) were men; 86% had 2 or more comorbid medical illnesses, 67% of which included coronary artery disease. Technical success, on an intent-to-treat basis was achieved in 93.8% of patients. Primary clinical success, which included freedom from aneurysm-related death, type I or III endoleak, graft infection or thrombosis, rupture, or conversion to open repair was 65 +/- 6% at 8 years. Of great importance, freedom from aneurysm rupture after ESG insertion was 98 +/- 1% at 9 years. There was a 2.3% incidence of perioperative mortality. One hundred seventy five patients died of causes not related to their aneurysm during a mean follow-up of 15.4 months. CONCLUSIONS: Stent graft therapy for aortic aneurysms is a valuable alternative to open aortic repair, especially in older sicker patients with large aneurysms. Continued device improvements coupled with an enhanced understanding of the important role of aortic pathology in determining therapeutic success will eventually permit ESGs to be a more durable treatment of aortic aneurysms.     

腔内隔绝术微创治疗肾下腹主动脉瘤

我科2003年6月至12月应用微创人造血管腔内隔绝术（endovascular graft exclusion，EVGE）治疗肾下腹主动脉瘤（abdominal aortic aneurysms，AAA）4例，现报道如下。     

Successful renal transplantation after endovascular bifurcated stent graft repair of an abdominal aortic aneurysm

Renal transplantation after repair of aortoiliac aneurysms with traditional prosthetic vascular grafts has been shown to be effective. Vascular surgery continues to rapidly evolve, most notably with the advancement of endovascular repair of abdominal aortic aneurysms. Controlled trials continue to support the trend toward the use of endovascular bifurcated aortic stent grafts. For this we describe the first renal transplant in a patient with an endovascular bifurcated aortoiliac stent graft. No intraoperative difficulties were encountered. At 1-year follow-up, the transplanted kidney is functioning well with a normal serum creatinine level of 1.3 mg/dl, and the patient has no worsening of peripheral vascular disease. We recommend that the presence of an endovascular aortic graft not be a contraindication to renal transplantation.     

Prosthetic stent graft infection after endovascular abdominal aortic aneurysm repair

OBJECTIVE: The purpose of this report is to discuss the incidence, diagnosis, and management of stent graft infections after endovascular aneurysm repair (EVAR). METHODS: Data were collected from the hospital database and medical case notes for all patients with infected endografts after elective or emergency EVAR for abdominal aortic aneurysm (AAA) during the last 8 years in two university teaching hospitals in Northern Ireland. The data included the patient's age, gender, presentation of sepsis, treatment offered, and the ultimate outcome. The diagnosis of graft-related sepsis was established by a combination of investigations including inflammatory markers, labelled white cell scan, computed tomography (CT) scan, microbiology cultures, and postmortem examination. RESULTS: Graft-related septic complications occurred in six of 509 patients, including 433 elective repairs and 76 emergency endografts for ruptured AAA. Two patients presented with left psoas abscess and were treated successfully with extra-anatomic bypass and removal of the infected stent graft. Two more patients presented with infected graft without other evidence of intra-abdominal sepsis: one underwent successful removal of the infected prosthesis with extra-anatomical bypass, and the other was treated conservatively and died of progressively worsening sepsis. The fifth patient presented with unexplained fever and died suddenly, with a postmortem diagnosis of aortoenteric fistula and ruptured aneurysm. The last patient presented with an aortoenteric fistula, was treated conservatively in view of concurrent myelodysplasia, and died of possible aneurysm rupture. CONCLUSION: This report emphasizes the need for continued awareness of potential graft-related septic complications in patients undergoing EVAR of AAA. Attention to detail with regard to sterility and antibiotic prophylaxis during stent grafting and during any secondary interventions is vital in reducing the risk of infection. In addition, early recognition and prompt treatment are essential for a successful outcome.     

Endovascular repair of abdominal aortic aneurysms: device-specific outcome

OBJECTIVES: Endovascular repair of abdominal aortic aneurysms, while advantageous because of its minimally invasive nature, falls short of achieving the long-term durability of traditional open surgical repair. Problems such as device migration, continued sac pressurization from endoleak, and graft limb thrombosis culminate in a high rate of secondary procedures and failure to protect against aneurysm rupture. While prior studies hint at a correlation between these postprocedural events and specific device design, a single comparative analysis that correlates device attributes with clinical outcome has not been performed. METHODS: Over 6 years ending in 2002, 703 patients underwent endovascular treatment of infrarenal abdominal aortic aneurysms. During this time, five devices were used, ie, Ancure, AneuRx, Excluder, Talent, and Zenith, and six device-specific groups were analyzed; the Zenith group was subdivided into those placed as part of the multicenter trial (Zenith-MCT) and those under a sponsor-investigator investigational device exemption trial (Zenith-SIT). Results were assessed with the Kaplan-Meier method for censored data, and the log-rank test was used to ascertain differences between device groups. RESULTS: While overall survival was diminished in the Zenith-SIT group (P =.046), risk for aneurysm-related death was similar in all groups (P =.336), averaging 2% or less at 12 months. Among the total cohort of patients, freedom from rupture was 98.7% +/- 0.9% at 24 months, without demonstrable differences between groups (P =.533). There were no statistically significant differences in rate of secondary procedures, conversion to open repair, or migration. There were, however, significant differences in risk for graft limb occlusion and rate of endoleak between groups. Limb occlusion occurred most often with Ancure devices (11% +/- 4.6% at 12 months, P =.009). Endoleak of any type was most common with Excluder devices (64% +/- 11% at 12 months, P =.003), a finding directly related to increased frequency of type II leaks in that group (58% +/- 11% at 12 months, P =.001). While there were no differences in frequency of type I or type III endoleak, a trend toward increased risk for microleak was observed with AneuRx devices (4.0% +/- 1.3%, P =.054), and more modular separations were observed with Zenith devices (3.5% +/- 2.3%, P =.032). Shrinkage at 12 months correlated with frequency of endoleak in the device groups, and was most common in the two Zenith groups (54% +/- 7.3% in the Zenith-MCT group and 56% +/- 7.8% in the Zenith-SIT group) and the Talent group (52% +/- 9.7%) and was least in the Excluder group (15% +/- 7.9% at 12 months, P <.001). By contrast, sac growth occurred most often in the Zenith-SIT group (13% +/- 4.5% at 12 months, P =.034), possibly as a result of the challenging aortoiliac anatomy frequently present in these patients. CONCLUSIONS: There are significant differences in frequency of limb occlusion and endoleak between groups with different endovascular devices. Knowledge of these and other differences is instructional in development of next-generation endovascular devices, incorporating design features linked to satisfactory outcome while abandoning those associated with device failure.     

腹主动脉瘤的腔内修复治疗

腹主动脉瘤 (abdominalaorticaneurysms ,AAA)是血管外科常见的严重疾病 ,发病高峰年龄在 6 0～ 70岁之间 ,发病率男性是女性的 4～ 6倍 ,95 %的病例位于肾动脉平面以下。AAA最大的危险是瘤体破裂引起的致死性出血。通常认为 :瘤体 <5cm的AAA破裂发生率每年约 3% ;直径在 5～ 6cm的破裂发生率每年上升 10 %。一旦发生破裂 ,病死率高达 90 % ,手术死亡率 4 1%～ 70 % ,而择期手术死亡率仅 3%～ 5 %。因此只要无心、肺、肾功能不全等手术禁忌 ,本病均有手术适应证。最近的文献报告 ,AAA直径≥ 5 5cm是手术适应证[1] 。195 2年 ,Dubost[…     

Endovascular repair of infrarenal abdominal aortic aneurysms in high-risk-surgical patients.

PURPOSE: Following the publication of a prospective randomized trial (EVAR2) that questioned the benefit of endovascular repair of abdominal aortic aneurysms (AAA) for high-surgical-risk patients, we evaluated our own initial and long-term results with endovascular AAA repair for this patient population. MATERIAL AND METHODS: Between January 2000 and December 2005, 115 patients with an AAA managed by an aortic endograft were entered in a registry. Data concerning diagnosis, operative risk, treatment, and follow-up were analyzed on an intention-to-treat basis for all patients considered to be poor candidates for surgery. Patients with a ruptured AAA and those who were good surgical candidates were excluded from analysis. The main goal was evaluation of the operative mortality and the long-term survival of these patients. Secondary goals were determination of the frequency of secondary operations, the outcome of the aneurysm sac, and primary and secondary patency rates after aortic endograft placement. RESULTS: A total of 92 high-surgical-risk patients treated by an endograft were entered in this study. Sixty-seven patients (73%) were classed ASA III and 18 (20%) were ASA IV (20%). Mean aneurysm diameter was 58 mm+/-9 mm. The technical success rate was 99%. Operative mortality was 4.3% (4 cases). Four patients required re-intervention during the mean follow-up of 18 months. The survival rate at 3 yr was 85%. One type I endoleak (1%) and 9 type II endoleaks (9.7%) occurred during the follow-up period. Primary and secondary patency rates at 3 yr were respectively 96% and 100%. CONCLUSION: Our initial and long-term results with endograft repair of AAA in high-surgical-risk patients were satisfactory. These results appear to justify endovascular repair for this patient population.     

Open versus endovascular stent graft repair for abdominal aortic aneurysms: an historical view

Development of endovascular abdominal aortic aneurysms repair (EVAR), now in its 4th decade, has involved at least 16 different devices, not counting major modifications of some, only 4 of which have emerged from clinical trials and gained US Food and Drug Administration approval. The main impetus behind EVAR has been its potential for significantly reducing procedural mortality and morbidity, but it was also expected to speed recovery and reduce costs through decreased use of hospital resources. At the outset, EVAR was touted as a better alternative to OPEN in high-risk patients with large abdominal aortic aneurysms, and to "watchful waiting" (periodic ultrasound surveillance) for those with small abdominal aortic aneurysms. This new technology has evoked a mixed response with enthusiasts and detractors debating its pros and cons. Bias and conflict of interest exist on both sides. This review will attempt to present a balanced review of the development and current status of this controversial competition between EVAR and OPEN, comparing them in terms of the following key considerations: mortality and morbidity, complications, failure modes and durability, and costs.     

Endovascular stent graft repair of mycotic aneurysms of the thoracic aorta

Traditional open surgical repair for mycotic aneurysms of the thoracic aorta is associated with significant morbidity and mortality. Endovascular repair has been reported as an alternative treatment in patients with mycotic thoracic aneurysms. This article reports our experience of endovascular stent graft placement in three patients with mycotic aneurysms of the thoracic aorta and compares the results with similar reports on the literature.     

Endovascular repair of abdominal aortic aneurysms: risk stratified outcomes

OBJECTIVE: The impact of co-morbid conditions on early and late clinical outcomes after endovascular treatment of abdominal aortic aneurysm (AAA) was assessed in concurrent cohorts of patients stratified with respect to risk for intervention. SUMMARY BACKGROUND DATA: As a minimally invasive strategy for the treatment of AAA, endovascular repair has been embraced with enthusiasm for all prospective patients who are suitable anatomical candidates because of the promise of achieving a durable result with a reduced risk of perioperative morbidity and mortality. METHODS: From April 1994 to March 2001, endovascular AAA repair was performed in 236 patients using commercially available systems. A subset of patients considered at increased risk for intervention (n = 123) were categorized, as such, based on a preexisting history of ischemic coronary artery disease, with documentation of myocardial infarction (60%) or congestive heart failure (35%), or due to the presence of chronic obstructive disease (21%), liver disease, or malignancy. RESULTS: Perioperative mortality (30-day) was 6.5% in the increased-risk patients as compared to 1.8% among those classified as low risk (P = NS). There was no difference between groups in age (74 +/- 9 years vs. 72 +/- 6 years; mean +/- SD), surgical time (235 +/- 95 minutes vs. 219 +/- 84 minutes), blood loss (457 +/- 432 mL vs. 351 +/- 273 mL), postoperative hospital stay (4.8 +/- 3.4 days vs. 4.0 +/- 3.9 days), or days in the ICU (1.3 +/- 1.8 days vs. 0.5 +/- 1.6 days). Patients at increased risk of intervention had larger aneurysms than low-risk patients (59 +/- 13 mm vs. 51 +/- 14 mm; P <.05). Stent grafts were successfully implanted in 116 (95%) increased-risk versus 107 (95%) low-risk patients (P = NS). Conversion rates to open operative repair were similar in increased-risk and low-risk groups at 3% and 5%, respectively. The initial endoleak rate was 22% versus 20%, based on the first CT performed (either at discharge or 1 month; P = NS). To date, increased-risk patients have been followed for 17.4 +/- 15 months and low-risk patients for 16.3 +/- 14 months. Kaplan-Meier analysis for cumulative patient survival demonstrated a reduced probability of survival among those patients initially classified as at increased risk for intervention (P <.05, Mantel-Cox test). Both cohorts had similar two-year primary and secondary clinical success rates of approximately 75% and 80%, respectively. CONCLUSIONS: Early and late clinical outcomes are comparable after endovascular repair of AAA, regardless of risk-stratification. Notably, 2 years after endovascular repair, at least one in five patients was classified as a clinical failure. Given the need for close life-long surveillance and the continued uncertainty associated with clinical outcome, caution is dictated in advocating endovascular treatment for the patient who is otherwise considered an ideal candidate for standard open surgical repair.     

Endovascular stent graft repair of a thoracic aortic gunshot injury

Endovascular treatment approaches offer minimally invasive alternative strategies for the management of vascular injuries. While endovascular stent graft repair of blunt injury to the thoracic aorta is well described, there are few reports of its application for treatment of penetrating injuries of the thoracic aorta. We report the successful treatment of a through-and-through gunshot injury of the thoracic aorta and review how this technology may be applied for the treatment of penetrating thoracic aortic injury.     

Endovascular treatment of abdominal aortic aneurysms.

OBJECTIVE: The purpose of this paper is to briefly review the historical aspects and outcome of endoluminal abdominal aortic aneurysm (AAA) repair and summarise two studies presented at the 1997 and 1998 meetings of the Society for Vascular Surgery. PATIENTS: Between May 1992 and September 1998 the endoluminal method was used to repair arterial aneurysms in 304 patients at the Royal Prince Alfred Hospital, Sydney, a tertiary referral teaching hospital. The study focuses on 243 patients with true AAA who underwent primary repair. There were 17 females and 226 males with a mean age of 72 years. Co-morbidities leading to rejection for conventional open repair were present in 83 patients. The criteria for inclusion included a segment of thrombus-free aorta between the lowermost renal artery and the commencement of the aneurysm of 1.5 cm or greater and iliac arteries that allowed access to the aorta from the groin. The technique involved the delivery of an endograft into the abdominal aorta by means of a sheath inserted through the femoral or iliac artery. Laparotomy associated with conventional open repair was avoided. Outcome measures included clinical examination and contrast-enhanced computed tomography (CT) within 10 days, at 6, 12, 18 months after operation and then annually thereafter. RESULTS: Endografts were successfully deployed in 226 patients. In the remaining 17 patients endoluminal repair was converted to open repair. There were 8 deaths within 30 days of operation giving a perioperative mortality rate of 3.3%. The two studies presented to the Society for Vascular Surgery concern: (i) a concurrent comparison of the endoluminal versus open methods of treating AAA; and (ii) a comparison of adverse events following endoluminal repair of AAA during two consecutive periods of time.     

Endovascular repair of abdominal aortic aneurysms and other arterial lesions

Purpose: This report describes our experience with endovascular stented graft repair of abdominal aortic aneurysms and other arterial lesions.Methods: Between September 1990 and April 1994, 57 patients were treated with endovascular stented grafts (50 with abdominal aortic aneurysms or iliac aneurysms; five with traumatic arteriovenous fistulas; one with an infected femoral false aneurysm; and one with a false aneurysm of the proximal right common carotid artery). The devices consist of either a Dacron or an autogenous vein graft sutured to a balloon-expandable stent. The stented grafts are placed through remote arteriotomies, advanced under fluoroscopic guidance to their predetermined sites, and secured into position.Results: Forty of the 50 endovascular stented graft procedures used to treat abdominal aortic aneurysms or iliac aneurysms were considered successful, even though some secondary treatment was required in six patients (two open operations; four secondary endovascular procedures). The 10 failures include four early procedural deaths, one late procedural death, and five leaks. All five arteriovenous fistulas and the two false aneurysms were successfully treated with endovascular stented grafts.Conclusions: Although our experience with endovascular stented grafts has been promising, remaining problems require resolution, and further follow-up is needed. However, the potential advantages of these endovascular grafts warrant their continued evaluation. (J VASC SURG 1995;21:549-57.)     

Endovascular stent grafting of aortic aneurysms

This contribution reviews the current status of stent grafting for abdominal aortic aneurysms.