Noninvasive Diagnosis of Incomplete Endovascular Aneurysm Repair: D-Dimero assay to detect type I Endoleaks and nonshrinking aneurisms

Rationale: Persistent endoleaks(EL) due to inadequate stent attachment or fixation, have been generally considered a treatment failure, thus a primary endpoint in long term follow ups, even if most recently the axiom EL-increased AAA volume-rupture has been criticized. Since it has been shown that even patients with a negative early follow up are not exempt from risks for late endoleak formation or rupture , a warning has been raised in that all patients treated with endovascular devices should be carefully followed lifetime. Therefore , non invasive and non expensive tools for detection of an imperfect endograft functioning are needed.Thesis: in presence of a demonstrable peri graft flow and generally in case of an increasing sac volume, active intravascular thrombus formation occurs and specific markers for endogenous fibrinolysis could detect them and alert for further investigation. D \u2013Dimer (D-D) is a plasmin resistant fibrin fragment which , in the diagnosis of intra vascular thrombosis, has shown high specificity ,sensitivity and high negative predictive value. Methods: We analyzed the D -D blood level in 83 patients selected by the following carachteristics:1. affected by AAA, 2.evaluated and treated with endovascular exclusion with AneuRx Endograft, in follow up after an implant with 3. no endoleak and decreasing volume, 4. with type I endolaeks, 5. Type 2 endoleaks, with 6. Invariated or increased or 7. decreased sac maximal diameter.Plasma was drown in correspondence of the TC scan and clinical monitoring relative to which information on AAA where drown. Plasma was frozen and analyzed for D-D through a Latex quantitative test. Results were stratified according to the patient\u2019s clinical stage. Results: D-D values presented a high interpersonal variability with generally width standard deviations. D \u2013D values do not significantly varied among patients with stable AAA and age matched controls ( 238\ub1245 vg/ml vs 421\ub1 400vg/ml, p> 0.05) . D- D values increase significantly (727\ub1 345 vg/ml vs 421\ub1400 vg/ml p<0.05) immediately after treatment (4th p.o. day). Values do not significantly vary at various distance from the procedure if there is no EL and AAA volume decrease or if Type 2 EL were present. D-D values significantly increased (1931\ub1 924 vg/ml, p< 0.005 vs all other groups) in case of Type 1 EL and in case of EL with unmodified or increasing AAA diameters in comparison with EL and decreasing diameters (1177\ub1 773 vg/ml vs 778\ub1466 vg/ml, p< 0.005).Conclusion: elevated D-D may prove to be a useful arker for fixation problems after endovascular repair and may help rule out of type I endoleak, thus excluding patients from unnecessary invasive tests

Non invasive diagnosis of incomplete endovascular aneurysm repair: the D-Dimer assay on venous blood samples can reveal type I endoleak and non decreasing size of abdominal aortic aneurysm

Purpose: To test the hypothesis that D-dimer (D-D), a cross-linked fibrin degradation product of an ongoing thrombotic event, could be a marker for incomplete aneurysm exclusion after endovascular abdominal aortic aneurysm (AAA) repair. Methods: In a multicenter study, 83 venous blood samples were collected from 74 AAA endograft patients and controls. Twenty subjects who were >6 months postimplantation and had evidence of an endoleak and/or an unmodified or increasing AAA sac diameter formed the test group. Controls were 10 nondiseased subjects >65 years old, 18 AAA surgical candidates, and 26 postoperative endograft patients with no endoleak and a shrinking aneurysm. Blood samples were analyzed for D-D through a latex turbidimetric immunoassay. The endograft patients were stratified into 5 clinical groups for analysis: no endoleak and decreasing sac diameter, no endoleak and increasing/unchanged sac diameter, type II endoleak and decreasing sac diameter, type II endoleak and increasing/unchanged sac diameter, and type I endoleak. Results: Individual D-D values were highly variable, but differences among clinical groups were statistically significant (p 0.05). Median D-D values increased at 4 days postoperatively (963 ng/mL versus 382 ng/mL, p > 0.05) and did not vary thereafter if there was no endoleak and the aneurysm sac decreased. D-D mean values were higher in patients with type I endoleak (1931 ± 924 ng/mL, p < 0.005) and those with unchanged/increasing sac diameters (1272 ± 728 ng/mL) than in cases with decreasing diameters (median 638 ± 238 ng/mL) despite the presence of endoleak (p < 0.0005). Conclusions: Elevated D-D may prove to be a useful marker for fixation problems after endovascular AAA repair and may help rule out type I endoleak, thus excluding patients from unnecessary invasive tests