Visceral embolization during low-dose fibrinolysis of aortic graft occlusion

Abstract

Recently there has been increased interest in the treat ment of patients with acute vascular occlusions with selec tive intraarterial infusion of low-dose fibrinolytic agents [1][2][3]. This method, introduced by Dotter et al. in 1974 [4], is as effective as systemic fibrinolysis but has less morbidity.Hemorrhagic complications with low-dose fibrinolysis are significantly reduced. Fever and allergic reactions due to the antigenicity of the drug are rare [5]. Distal embolization is a potential complication; however, it has not been of major DiscussionThe pharmacology, technique, and indications for lowdose intraarterial fibrinolysis have been well described re cently [1-3, 6]. Peripheral embolization during this proce dure has been reported or suspected in several cases [1, 3, 4]; however, to the best of our knowledge, none have had the catastrophic outcome that occurred in our patient.We speculate that the mechanism of this massive embo lization may have been the combination of fresh and old clot within the thrombus lysing at different sites and stages [7].The fresh clot may be lysed first. It is possible that the proximal systolic aortic pulsations may then have a "sand blasting" or "whirlpooling" effect, which may liberate the older and more resistant clot fragments. This is only conjec ture and could be studied in vitro and in animal models.Once these clot fragments are liberated, it is clear that they could then be carried peripherally through the vessels of greatest outflow and least resistance, which in this case, since the aorta was occluded, were the renal and superior mesenteric arteries.An initial loading dose of streptokinase of 2000 U/min during the first hour has been advocated recently [8]. We have been giving a loading dose routinely to our patients.The loading dose assists in neutralizing the circulating anti bodies present in most individuals and allows a rapid as sessment of the potential lytic effects. It is tempting to postulate that the loading dose may have accelerated the lysis of fresh clot, thereby increasing the likelihood of pe-

Editor's Choice – European Society for Vascular Surgery (ESVS) 2020 Clinical Practice Guidelines on the Management of Acute Limb Ischaemia

“…Clots may also detach and pass cranially from the proximal end of the occlusion, a phenomenon known as whirlpool embolism. 276 Primary distal thrombosis of the hand (or residual distal ischaemia after embolectomy) may benefit from CDT or intravenous prostaglandin therapy.…”

Thrombolytic therapy

“…2 Distal embolization secondary to lysis of arterial thrombi has been reported. 17 It is speculated that this complication occurs when a combination of fresh and old thrombus is present. Rapid lysis of the fresh clot, along with arterial pulsations, may liberate older and more resistant clot fragments.…”