PERSISTENT COLLATERAL PERFUSION OF ABDOMINAL AORTIC-ANEURYSM AFTER ENDOVASCULAR REPAIR DOES NOT LEAD TO PROGRESSIVE CHANGE IN ANEURYSM DIAMETER

Purpose: To differentiate between the phenomenon of collateral perfusi on from a side branch versus graft-related endoleaks after endovascula r repair of abdominal aortic aneurysms (AAA), with respect to aneurysm size and prognosis. Methods: We successfully treated 64 AAA patients with endovascular grafting. We followed all the patients postoperative ly with spiral computed tomography at one, three, six and 12 months, a nd biannually thereafter. We measured aneurysm diameters preoperativel y and postoperatively. We calculated preoperatively the relation of ma ximum aortic diameter (D) to the thrombus-free lumen diameter (L) expr essed as an L/D ratio. Median follow-up was 15 months. Results: Sixtee n patients had collateral perfusion during follow-up. We successfully treated two patients with embolization. One patient showed resolution of collateral perfusion after we stopped warfarin treatment. Two patie nts died of unrelated causes during follow-up. One patient was convert ed to surgical treatment, and two patients showed spontaneous resoluti on of their collateral perfusion. The group of patients with perfusion showed no statistically significant change of their aortic diameter o n follow-up. The group of patients without perfusion showed a median d ecrease in aortic diameter of 8mm (p < 0.0001) at 18 months postoperat ively. The group of patients with perfusion had significantly less thr ombus in their aneurysm sac preoperatively than the group without perf usion, as expressed by the L/D ratio (mean L/D 0,61 versus 0,78, respe ctively; p=0.0021.) Conclusion: There was no significant increase in a ortic diameter on an average 18 months postoperatively despite persist ent collateral perfusion. This may indicate a halted disease progressi on in the short term. Embolization of collateral vessels is associated with risk of paraplegia. We recommend a conservative approach with cl ose observation if aneurysm diameter is stable.