The use of thrombin in the radiology department

Abstract

Thrombin is a naturally occurring coagulation protein that converts soluble fibrinogen into insoluble fibrin and plays a vital role in the coagulation cascade and in turn haemostasis. Thrombin also promotes platelet activation. In the last few years, there has been a rapid increase in the use of thrombin by radiologists in a variety of clinical circumstances. It is best known for its use in the treatment of pseudoaneurysms following angiography. However, there are now a variety of cases in the literature describing the treatment of traumatic, inflammatory and infected aneurysms with thrombin in a variety of locations within the human body. There have even been recent reports describing the use of thrombin in conventional aneurysms as well as ruptured aneurysms. Its use has also been described in the treatment of endoleaks (type II) following aneurysm repair. In nearly all of these cases, treatment with thrombin requires imaging guidance. Recently, thrombin has also been used as a topical treatment post-percutaneous intervention to reduce or stop bleeding. Most radiologists have only a limited knowledge of the pharmacodynamics of thrombin, its wide range of utilisation and its limitations. Apart from a few case reports and case series, there is little in the radiological literature encompassing the wide range of applications that thrombin may have in the radiology department. In this review article, we comprehensively describe the role and pathophysiology of thrombin, describing with examples many of its potential uses. Techniques of usage as well as pitfalls and limitations are also described.

Miscellaneous Pharmaceutical Agents in Interventional Radiology

“…Because thrombin administration works by initiating the clotting cascade, injection should stop as soon as clot formation is visualized on duplex ultrasound. [1][2][3]27,28 Indications: The most common use of intravascular thrombin is for PSA repair in peripheral vessels, where the goal is to thrombose the false sac to prevent future rupture and to decrease the risk of distal embolization. The first description of percutaneous injection of thrombin to repair postcatheterization PSA was reported by Cope and Zeit in 1986.…”

“…True aneurysms of the splenic artery 43 are reported to be amenable to thrombin injection alone; however, in other arterial locations its role is mainly as an adjunct to embolic coils. 27 When used as an adjunct, coils may be soaked in thrombin to facilitate vessel thrombosis. In true aneurysms, thrombin must be injected very slowly to assure no injection into the systemic circulation.…”

“…Repair of type II endoleaks with thrombin injection is associated with low morbidity. 48,49 Complications and Contraindications: Complication rates of thrombin injection are low (<4%), 27,34,50 but can be serious and dictate careful patient selection. Downstream thromboembolic events are the highest reported serious complication (0.8%) 33 ; patient pulses and ankle-brachial indexes must be recorded prior to the procedure.…”

“…In the event of distal nontarget occlusion, prompt intraarterial thrombolysis should be performed. 27,28,34,51 In the event of recanalization (2% of cases), a second attempt can be made; however, lower success rates are noted with such repeat procedures. 33 If deemed necessary, ultrasound follow-up 7 to 10 days later can assure PSA thrombosis.…”

“…D-stat 1 flowable is a similar product mixed into a thick solution that can be applied into sites of surface bleeding with a syringe-like device. 1,27,55 Indications: Topical thrombin is becoming increasingly popular for its hemostatic properties after interventional procedures. Many patients undergoing procedures in the interventional suite have underlying platelet dysfunction or coagulopathies, and cessation of surface bleeding is difficult to achieve.…”