Concurrent comparison of endoluminal repair vs. no treatment for small abdominal aortic aneurysms

Endoluminal Repair of Abdominal Aortic Aneurysms: Strengths and Weaknesses of Various Prostheses Observed in a 4.5-Year Experience

Purpose:

To summarize the results of endovascular abdominal aortic aneurysm (AAA) treatment using several endograft designs over a 4.5-year experience and offer comparisons on the various devices.

Methods:

From May 1992 to August 1996, 121 AAA patients meeting the criteria for an endoluminal repair were treated with 1 of 5 endograft designs in three configurations. The endografts were implanted in the operating room under fluoroscopic control. Follow-up included contrast-enhanced computed tomography within 10 days of operation, 6 months postoperatively, and annually thereafter.

Results:

Endografts were successfully deployed in 106 patients (88%). Fifteen cases were converted to open repair. Six procedure-related deaths occurred within 30 days owing to myocardial infarction (3), combined renal failure and septicemia (2), and multisystem failure (1). There were 36 local/vascular complications (30%) and 18 systemic/remote complications (15%). Of the 121 patients undergoing endoluminal AAA repair, 93 (77%) are currently alive and well with their AAAs excluded from the circulation.

Conclusions:

Trends in endoluminal AAA repair and prosthetic design point toward simpler devices and earlier treatment of smaller aneurysms once the long-term outcome of aortic endografting has been determined.

Systematic review of cardiovascular disease and cardiovascular death in patients with a small abdominal aortic aneurysm

Background

Screening for abdominal aortic aneurysm (AAA) has reduced the rate of AAA rupture. However, cardiovascular disease is still a major cause of death in men with an AAA. The aim of this study was to assess cardiovascular risk in patients with a small AAA.

Methods

Standard PRISMA guidelines were followed. Analysis was performed of studies reporting cardiovascular outcomes in patients with a small AAA (30–54 mm). Weighted metaregression was performed for cardiovascular death in patients with a small AAA, and the prevalence of cardiovascular disease was reviewed.

Results

Twenty-one articles were identified describing patients with an AAA, and the prevalence of, and death from, cardiovascular disease. Ten of these reported cardiovascular death rates in patients with a small AAA. Some 2323 patients with a small AAA were identified; 335 cardiovascular deaths occurred, of which 37 were due to AAA rupture. Metaregression demonstrated that the risk of cardiovascular death was 3·0 (95 per cent c.i. 1·7 to 4·3) per cent per year in patients with a small AAA (R2 = 0·902, P < 0·001). The prevalence of ischaemic heart disease (44·9 per cent), myocardial infarction (26·8 per cent), heart failure (4·4 per cent) and stroke (14·0 per cent) was also high in these patients.

Conclusion

The risk of cardiovascular death in patients with a small AAA is high and increases by approximately 3 per cent each year after diagnosis. Patients with a small AAA have a high prevalence of cardiovascular disease. Patients a small AAA should be considered for lifestyle modifications and secondary cardiovascular protection.

Diameter of abdominal aortic aneurysm and outcome of endovascular aneurysm repair: does size matter? A report from EUROSTAR

OBJECTIVES

This study was undertaken to determine the effect of the preoperative diameter of abdominal aortic aneurysms on the midterm outcome after endovascular abdominal aneurysm repair (EVAR).

METHOD

The data for 4392 patients who had undergone EVAR were analyzed. Patients were enrolled over 6 years to June 2002 in the EUROSTAR database. Outcomes were compared between three groups defined by the preoperative diameter of the aneurysm: group A (n = 1962), 4.0 to 5.4 cm; group B (n = 1528), 5.5 to 6.4 cm; and group C (n = 902), 6.5 cm or larger. Patient characteristics, details of aortoiliac anatomy, operative procedures, old or current device generation, and postoperative complications in the three patient groups were compared. Outcome events included aneurysm-related death, unrelated death, conversion, and post-EVAR rupture of the aneurysm. Life table analysis and log-rank tests were used to compare outcome in the three study groups. Multivariate Cox models were used to determine whether baseline and follow-up variables were independently associated with adverse outcome events.

RESULTS

Patients in group C were significantly older than patients in groups A and B (73 years vs 70 and 72 years, respectively; P =.003 - P <.0001 for different group comparisons), and more frequently were at higher operative risk (American Society of Anesthesiologists classification >or=3; 63% vs 48% and 54%; P =.0002-P <.0001). Device-related (type I) endoleaks were more frequently observed at early postoperative arteriography in group C compared with groups A and B (9.9% vs 3.7% and 6.8%; P =.01-P <.0001). Postoperatively systemic complications were more frequently present in group C (17.4% vs 12.0% in group A and 12.6% in group B; P <.0001 and.001). The first-month mortality was approximately twice as high in group C compared with the other groups combined (4.1% vs 2.1%; P <.0001). Late rupture was most frequent in group C. Follow-up results at midterm were less favorable in groups C and B compared with group A (freedom from rupture, 90%, 98%, and 98% at 4 years in groups C, B, and A, respectively; P <.0001 for group C vs groups A and B). Aneurysm-related death was highest in group C (88% freedom at 4 years, compared with 95% in group B and 97% in A; P =.001 and P <.0001, respectively; group B vs A, P =.004). The annual rate of aneurysm-related death in group C was 1% in the first 3 years, but accelerated to 8.0% in the fourth year. Incidence of unrelated death also was higher in groups C and B than in group A (76% and 82% freedom at 4 years vs 87%; P <.0001 for both comparisons). Ratio of aneurysm-related to unrelated death was 23%, 21%, and 50% in groups A, B, and C, respectively. Cox models demonstrated that the correlation between large aneurysms (group C) and all assessed outcome events was independent and highly significant. Older generation devices had an independent association with aneurysm-related and unrelated deaths (P =.02 and P =.04, respectively). However, this correlation was less strong than large aneurysm diameter (P =.0001 and P =.0009, respectively).

CONCLUSIONS

The midterm outcome of large aneurysms after EVAR was associated with increased rates of aneurysm-related death, unrelated death, and rupture. Reports of EVAR should stratify their outcomes according to the diameter of the aneurysm. Large aneurysms need a more rigorous post-EVAR surveillance schedule than do smaller aneurysms. In small aneurysms EVAR was associated with excellent outcome. This finding may justify reappraisal of currently accepted management strategies.

Stent Grafts for the Treatment of Abdominal Aortic Aneurysms

Stent grafting for treatment of abdominal aortic aneurysms (AAAs) has been a major advance in endovascular surgery. Initial success with the original endoluminal stent graft encouraged worldwide study of the technology. In the United States, the Food and Drug Administration (FDA) insisted on considerable experience with the devices before approval because of early problems with device rupture, stent fracture, fabric perforation, graft migration, and modular separation. Complications associated with the endovascular graft technology led many to recommend its use only in patients who were considered at "high risk" for the standard, open procedure. Further study and device improvements have led to results that indicate the procedure has the potential to reduce operating time and blood loss and shorten intensive care unit and hospital stays compared with open surgical intervention. At present, there are three FDA-approved devices available for use, and a fourth is expected in 2003. The ultimate decision by the individual practitioner or the institutional team regarding which patients should be treated with endovascular technology is still not entirely straightforward. Patient selection should be based on vascular anatomy, the availability of a suitable device, the patient's desire for a minimally invasive procedure, and a commitment to what is likely to be a lifetime of device surveillance.

Predictive factors for early success of endovascular abdominal aortic aneurysm repair

To identify predictive factors for postoperative success and potential predictors for satisfactory outcome of endovascular grafting for abdominal aortic aneurysm (AAA), we collected data from our prospective database, which includes a series of consecutive patients undergoing endovascular repair at the Vascular Surgery Unit, Policlinico Monteluce, Perugia, Italy. From April 1997 to July 1998, 202 patients were referred to our Unit for elective AAA repair; 94 patients (47%) were selected for endografting. Placement of the graft using endovascular technique without conversion to open laparotomy, in addition to no mortality, major morbidity, or endoleak at 30-day follow-up, was defined as postoperative success. The influence of anatomical features on postoperative results was analyzed by univariate and multivariate analysis. Our experience shows that endoluminal repair of AAA is safe and effective in the short term and male patients with small aneurysms are optimal candidates for successful repair.

An evaluation of the costs to health care institutions of endovascular aortic aneurysm repair

BACKGROUND

Endovascular graft techniques hold great potential as a less invasive means for the repair of aortic aneurysms, yet the impact of these new modalities remains poorly elucidated.

METHODS

Over a 10-month period at a single institution, 139 patients underwent infrarenal aortic aneurysm repair through a traditional open surgical technique (OS group, 94 patients) or an endovascular approach (ES group, 45 patients). Coated polyester prostheses (Hemashield; Boston Scientific Corporation, Boston, Mass) were used in the OS patients, whereas a modular nitinol polyester device (AneuRx; Medtronic, Sunnyvale, Calif) was used in the ES group. The hospital costs exclusive of professional charges were tabulated for the two groups using the hospital cost accounting system. Outliers were included in the data analysis.

RESULTS

The mean operating room time was longer in the OS group than in the ES group (285 minutes vs 166 minutes). The average length of stay was also longer in the OS group (9.7 days vs 3.2 days). Hospital costs related to the length of stay were higher in the OS group, including laboratory costs ($327 higher), pharmacy costs ($688 higher), and nursing costs ($780 higher). Anesthesia costs were also higher in the OS group ($493 higher). Despite these marked differences, the total hospital cost averaged $7205 more in the ES group, a finding that was driven by the cost of the implantable devices themselves ($8976 in the ES group vs $597 in the OS group).

CONCLUSIONS

Despite reductions in the length of hospitalization, the cost of care was substantially greater in patients undergoing endovascular aneurysm repair than in patients in whom an open surgical technique was used. These differences are driven by the cost of the endograft device itself, a cost that must not exceed $6000 if the economic impact of endovascular repair is to be in parity with traditional methods. Unless these economic disparities can be ameliorated, the economic impact of endovascular aneurysm repair may limit the widespread application of this technology.

The fate of patients undergoing surveillance of small abdominal aortic aneurysms

OBJECTIVES

Increasing numbers of patients with small abdominal aortic aneurysms (AAA) are being diagnosed. The aim of this paper is to define the fate of those patients undergoing surveillance of small AAAs.

SETTING

U.K. district general hospital.

METHODS

A prospective study has been carried out of all patients undergoing surveillance. At the time of the first consultation the patient was assessed, a Detsky score calculated and the referral source noted. End points of the study were elective repair of the aneurysm, aneurysm rupture or death of the patient.

RESULTS

Details of 267 patients were analysed. The referral source was general practitioner in 39%, patients with peripheral vascular disease in 32% and department of urology in 21%. None were referred from population screening. The cumulative 5-year risks of rupture, elective repair or non-AAA related deaths were 15%, 26% and 46% for all patients, 4%, 13% and 38% for patients initially presenting with AAA less than 4 cm diameter and 21%, 42% and 54% for patients presenting with an AAA 4-5.5 cm diameter. All but one of 11 patients whose aneurysm ruptured were unfit or had declined elective repair. There were 56 non-AAA related deaths, the majority due to cardiovascular causes. Those patients with low Detsky scores had a 5-year survival of 62%, those with high scores 44%. The age/sex matched survival or a normal population at 5 years in 80%.

CONCLUSION

Overall the non-AAA related mortality was greater than the risks of rupture or elective repair. It is important to bear in mind the poor prognosis of this group of patients compared with a normal population when considering elective repair of small AAAs.

Endoluminal abdominal aortic aneurysm surgery

BACKGROUND

The development of devices designed for the endoluminal repair of abdominal aortic aneurysm has led to the emergence of new endovascular techniques.

METHODS

Articles and case reports obtained from a Medline search of the English language literature from 1989 to 1997 are reviewed. This search was carried out using the MeSH heading 'aortic aneurysm, abdominal' and the keywords 'endovascular' and 'endoluminal'.

RESULTS

Reported mortality and complication rates for endoluminal aneurysm repair are similar to those following conventional repair, with the exception of continued perfusion of the aneurysm sac which remains a major problem following endoluminal repair.

CONCLUSION

Successful endoluminal aneurysm exclusion is associated with reduced aneurysm diameter. However, longer term results of endoluminal repair, in particular of sealed endoleaks, are required before randomized controlled trials of endoluminal versus conventional repair can be undertaken.

Endoluminal repair of abdominal aortic aneurysms: strengths and weaknesses of various prostheses observed in a 4.5-year experience

PURPOSE

To summarize the results of endovascular abdominal aortic aneurysm (AAA) treatment using several endograft designs over a 4.5-year experience and offer comparisons on the various devices.

METHODS

From May 1992 to August 1996, 121 AAA patients meeting the criteria for an endoluminal repair were treated with 1 of 5 endograft designs in three configurations. The endografts were implanted in the operating room under fluoroscopic control. Follow-up included contrast-enhanced computed tomography within 10 days of operation, 6 months postoperatively, and annually thereafter.

RESULTS

Endografts were successfully deployed in 106 patients (88%). Fifteen cases were converted to open repair. Six procedure-related deaths occurred within 30 days owing to myocardial infarction (3), combined renal failure and septicemia (2), and multisystem failure (1). There were 36 local/vascular complications (30%) and 18 systemic/remote complications (15%). Of the 121 patients undergoing endoluminal AAA repair, 93 (77%) are currently alive and well with their AAAs excluded from the circulation.

CONCLUSIONS

Trends in endoluminal AAA repair and prosthetic design point toward simpler devices and earlier treatment of smaller aneurysms once the long-term outcome of aortic endografting has been determined.