Endovascular aneurysm repair with the AneuRx stent-graft is safe, but is it effective?

Endovascular Abdominal Aortic Aneurysm Repair

Although endovascular surgery for aortic aneurysms can be traced to the 19th century, open surgery has dominated during the past 50 years. Indeed, open repair of aneurysms has been one of the most successful developments in vascular surgery. Despite improvements in mortality rates, open repair remains a major operation often undertaken in patients with significant comorbidities. Starting from basic research dating back several decades, the 1990s were noted for very active clinical development of endovascular abdominal aortic repair in an attempt to provide an alternative to open repair, especially for high-risk patients. Early successes with decreased intensive care unit and hospital stays were tempered by technical issues and the “endoleak,” the term given to an incomplete exclusion of the aneurysm from the circulation. This potential for rupture, despite treatment, was cause for concern. The need for long-term surveillance and secondary procedures, if not conversion to open repair, further compounded these issues. Despite these concerns, progress continued, and by the end of 2002, the Food and Drug Administration had approved three devices for marketing. Although surgeons are faced with increasingly complex issues related to endovascular repair, anesthesiologists have found their management of this procedure to be simpler in many ways. The smaller incisions and improved hemodynamic stability have led to a variety of anesthetics being tried, including monitored anesthesia care. Anesthesiologists continue to explore a number of opportunities to improve patient outcome in these procedures. These include selection of the most optimal anesthetic, the most appropriate perioperative renal protection, and the best preparation for and management of a conversion to an open procedure. Whatever the final role for endovascular surgery in the management of abdominal aortic aneurysms, it is an intellectually stimulating and scientifically promising technique for surgeons, anesthesiologists, and the patients they serve.

Endo-exuberance and abdominal aortic aneurysm management: have we gone too far?

HYPOTHESIS

new technology, such as endovascular abdominal aortic aneurysm repair (EVAR) may promote an 'irrational exuberance' for its application.

METHODS

nonsuprarenal AAA repairs performed at a single institution over a 7 year period were retrospectively studied. Method of repair, 30-day mortality and EVAR aortic neck anatomy were assessed.

RESULTS

431 AAA repairs were performed between January 1996 and June 2002, 238 (55%) open and 193 (45%) EVAR. The percentage of EVAR increased steadily from approximately 20% in 1996 and 1997 to a peak of 69.5% in 2000. However, in 2001-2002 the percentage of EVAR fell to approximately 40% of total repairs. In this time period our selection criteria for EVAR became more conservative, with treatment of fewer patients with short aortic necks (12.8 vs. 28.9% with neck length < or = 20 mm, p = 0.05; 3.8 vs. 10.8% with neck length < or = 15 mm, p = 0.1) or highly angulated necks (3.8 vs. 28.9% with neck angulation > or = 40 degrees, p = 0.04) in 2001-2002 versus 1999-2000, respectively. Institutional volume of AAA repairs doubled over the study period (p = 0.001). 30-day mortality over the study period for nonruptured EVAR and open AAA repair was 2.6 and 3.3%, respectively (p = NS). The complexity of open repairs increased significantly during the final 3 years of the review.

CONCLUSIONS

the application of EVAR has fallen from a high of 69.5% of our AAA repairs in 2000 to approximately 40% in 2001-2002. More prudent patient selection in recent years regarding unfavorable aortic neck anatomy was felt to be a primary etiology of changes in overall EVAR utilization. The anticipated improvement in long-term results from EVAR await multi-year follow-up.

Midterm results of endovascular repair of descending thoracic aortic aneurysms with first-generation stent grafts

OBJECTIVE

Five years after reporting our initial stent-graft repair of descending thoracic aortic aneurysms experience, we determined the 5- to 10-year results of stent-graft treatment and identified risk factors for adverse late outcomes.

METHODS

Between 1992 and 1997, 103 patients (mean age 69 +/- 12 years) underwent repair using first-generation (custom-fabricated) stent grafts. Sixty-two patients (60%) were unsuitable candidates for conventional open surgical repair ("inoperable"). Follow-up was 100% complete (mean 4.5 +/- 2.5 years; maximum 10 years). Outcome variables included death and treatment failure (endoleak, aortic rupture, reintervention, and/or aortic-related or sudden death).

RESULTS

Overall actuarial survival was 82% +/- 4%, 49% +/- 5%, and 27% +/- 6% at 1, 5, and 8 years. Survival in open surgical candidates was 93% +/- 4% and 78% +/- 6% and at 1 and 5 years compared with 74% +/- 6% and 31% +/- 6% in those deemed inoperable (P <.001). Independent risk factors for death were older age (hazard ratio = 1.1; P =.008), previous stroke (hazard ratio = 2.8; P =.003), and being designated an inoperable candidate (hazard ratio = 1.9; P =.04). Actuarial freedom from aortic reintervention and treatment failure at 8 years was 70% +/- 6% and 39% +/- 8%, respectively. Earlier operative year (hazard ratio = 1.2; P =.07), larger distal landing zone diameter (hazard ratio = 1.1; P =.001), and transposition of the left subclavian artery (hazard ratio = 3.3; P =.008) were determinants of treatment failure.

CONCLUSIONS

Survival after aneurysm repair using crude, first-generation stent grafts was satisfactory in good operative candidates but bleak in the inoperable cohort, raising the question of whether asymptomatic patients should have even been treated. Late aortic complications were detected in many patients, reemphasizing the importance of serial imaging surveillance.