Evaluation of patient selection guidelines for endoluminal AAA repair withthe Zenith stent-graft: The Australasian experience

Purpose: To review the patient selection guidelines for endovascular repair of abdominal aortic aneurysms (AAA) using the Zenith Endovascular Graft an d establish an order of importance for each criterion. Methods: The Zenith Endovascular Graft Research Database was interrogated f or information on 238 patients (209 men; mean age 74.9 +/- 0.9 years, range 50-94) treated with a Zenith bifurcated graft from 1994 to 1998. The commo n complications of endoluminal AAA repair (endoleak, migration, graft occlu sion, graft kinking, conversion, and deployment failure) were analyzed to d etermine any associations with selection criteria. Results: By 1998, 69% of endograft patients did not meet the recommended gu idelines; however, primary and secondary aneurysm exclusion rates were 87% and 94%, respectively. Over a median follow-up of 13.4 months (interquartil e range 2.8-24.0), 38 (16%) patients developed 28 (74%) early and 10 (26%) late type-I endoleaks. The endoleak rate in necks less than or equal to 10 mm long was 57% (8/14). Endoleak was associated with a neck contour change >3 mm (p = 0.003) and neck length < 20 mm (p = 0.045). The risk of proximal endoleak was 4 times greater if at least one of the proximal neck guidelin es was breached; combined guideline deviations of "contour change and large diameter" (p = 0.0004), "Contour change and short length" (p = 0.006), "la rge diameter and short length" (p = 0.01), and "contour change and angle" ( p = 0.03) also increased the risk of endoleak. Endograft migration was seen in 10 (4.2%) cases; only neck diameter > 28 mm (p = 0.0024) was associated with this complication. Conclusions: Proximal neck contour, length, and diameter are the most impor tant criteria in terms of endoleak development. Breaching the proximal neck length criterion resulted in a 4-fold increase in endoleak, and combined d eviations from the guidelines multiplied the effect. Necks less than or equ al to 10 mm long are unsuitable for the standard Zenith graft.