Direct thrombin injection

Once detected, an aneurysm of the hepatic artery requires immediate treatment. Up to a certain size, intrahepatic aneurysms are treated by angiographic embolization. Coagulation by means of direct thrombin injection has also been described. (130) Larger aneurysms are treated by vascular surgery (ligation, vascular reconstruction, resection). (132, 137)... 

Ellis PK, Kennedy PT, Collins AJ, Blair PH (2003) The use of direct thrombin injection to treat a Type II endoleak following endovascular repair of abdominal aortic aneurysm. Cardiovasc Intervent Radiol 26 482-484... 

They reported the successful direct needle-injection of thrombin to thrombose peripheral pseudoaneurysms such as common iliac, peroneal, and hepatic pseudoaneurysms. Despite this interesting report, it was not until a decade later that the first report of ultrasound-guided direct thrombin-injection to close iatrogenic groin pseudoaneurysms was published, by Liau et al. [16]. 

If the aneurysm is amenable to direct percutaneous puncture, another option includes direct thrombin injection or coiling via an 18-gauge needle. Simultaneous balloon occlusion of the aneurysm neck via arterial access can be performed to prevent nontarget embolization. 

Given that thrombin is the central mediator of coagulation and amplifies its own production, it is a natural target for pharmacologic intervention. Direct thrombin inhibitors (DTIs) bind thrombin and prevent interactions with its substrates (Fig. 7-7). Several injectable DTIs are approved for use in the United States including lepirudin, bivalirudin, arga-troban, and desirudin. Several oral DTIs are currently in... 

Cope, C., Zeit, R. Coagulation of aneurysms by direct percutaneous thrombin injection. Amer. J. Roentgenol. 1986 147 383 - 387... 

Coil embolization has been one of the mainstays of VAA treatment and has been augmented with direct glue or thrombin injection. Coil design has not changed significantly. However, extremely precise deployment mechanisms such as electrolytic detachment are available today. 

Hirudin is a substance produced by medicinal leeches, which directly inactivates thrombin. Lepirudin is a synthetic version produced by recombinant DNA technology, which has to be given by injection. It is used specifically in patients that have developed hypersensitivity to heparin (see Chapter 3, page 35). 

The interaction of heparin with human plasma low-density lipoprotein has been studied by gel permeation chromatography A fraction containing degradation products of fibrinogen formed in blood plasma after injection of thrombin also contains a complex of fibrinogen and heparin. The rate of inactivation of thrombin and Factor by anti-thrombin has been shown to be directly proportional to the chain-length of heparin.The effects of heparin on the reactions catalysed by Factor have been examined.Heparin inhibits the ability of phospholipid to accelerate prothrombin activation in a mechanism which appears to involve the displacement of Factor X from the surface of the phospholipid. 

Direct puncture with an 18-g needle for coil, thrombin, or glue injection... 

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