eCommons@AKU Department of Medicine Department of Medicine November 2006 Thrombolytic therapy in cerebral venous sinus thrombosis. Ayeesha Kamran Kamal Agha Khan University, [email protected] Follow this and additional works at: http://ecommons.aku.edu/pakistan_fhs_mc_med_med Part of the Neurology Commons Recommended Citation Kamal, A. (2006). Thrombolytic therapy in cerebral venous sinus thrombosis.. JPMA. The Journal of the Pakistan Medical Association, 56(11), 538-540. Available at: http://ecommons.aku.edu/pakistan_fhs_mc_med_med/402 Review Article Thrombolytic therapy in Cerebral Venous Sinus Thrombosis Ayeesha K. Kamal Department of Medicine, The Aga Khan University Hospital, Karachi. Abstract be unpredictable with potentially dangerous deterioration. The use of thrombolytic agents to rapidly lyse the Thrombolytics or fibrinolytics are agents which lyse clot has emerged as a therapeutic modality, in concert with the formed clot. The platelet - fibrin composition of a spe- interventional neuroradiologic approaches to deliver the cific thrombus depends on the local development of fibrin, agent locally at the site of thrombosis.There are no random- platelet activation, and regional blood flow. At arterial flow ized, double blind, placebo, controlled trials to support rates, thrombi are predominantly platelet rich, and at venous thrombolysis as a first line therapy in patients with cerebral flow rates, more relevant to the pathology of CVT, coagula- venous sinus thrombosis compared to standard therapy tion seems to predominate. Thrombin (Factor II a) cleaves using anticoagulation with weight based dose adjusted fibrinogen to form fibrin which is the scaffolding for the unfractionated Heparin. Numerous case reports and a single clot. Thrombus growth is limited by the endogenous fibri- non randomized trial have shown that it is comparatively nolytic system. This system is composed of plasminogen, safe and may rescue patients who are deteriorating despite Plasminogen Activators (PA) and their inhibitors. Plasmin anticoagulation with unfractionated Heparin. Consideration mediates the degradation of fibrin. All fibrinolytic agents must be given to the use of thrombolysis in this group. This are essentially obligate plasminogen activators that have is an approach that must be restricted to centers with consid- variable electivity for clot bound fibrin. The two most com- erable experience in neurointerventional therapy. mon agents reportedly used in the setting of CVT are uroki- nase and recombinant tissue plasminogen activator (rTPA). Introduction The first report of systemic thrombolytic administra- Cerebral Venous Thrombosis (CVT) is a rare disor- tion for CVT is from 1971.3 This idea is not novel. The der with protean manifestations. It was associated with a development of neuroendovascular techniques has enabled mortality rate of 20% to 50% in older studies.1 However, the possibility of direct lytic administration into the affect- with the advent of MR venography, its wide range of mani- ed sinus with mechanical or rheolytic aspiration of the clot. festations, from relatively benign isolated pseudotumour The clinical rationale for this approach is that the clot is like syndrome to coma with malignant uncontrollable ICP removed and the occluded sinus is opened rapidly during have begun to be recognized. It is now believed that the the procedure. This rapid decanalization may potentially mortality rate for CVT ranges from 11% to 30%.2 Thus the improve the clinical outcome and decrease the morbidity prognosis is not uniformly poor. and secondary complications associated with CVT. The widespread accepted treatment for CVT is sys- There are no randomized, double blind, prospective, temic anticoagulation with Heparin or Heparinoid placebo controlled trials evaluating this approach to stan- (LMWH).Anticoagulation is believed to be beneficial as it dard systemic anticoagulation. Canhao et al have reviewed the literature until 2001, reporting 72 publications, involv- possibly prevents further venous clot propagation. It is not ing 169 patients.4 One third of these patients had some known, given the variability and unpredictable course of the haemorrhage on their pretreatment CT or MRI scans, disease, whether this mode of treatment will prevent pro- whereas 32% of these patients were in coma. These case gression in all patients. series are non uniform and the treatment has been utilized in Thrombolytic administration represents an alternate both deteriorating patients plus those who had a good neu- mode of therapy which may be used for patients with pro- rologic status but a large clot burden on angiogram. gression despite adequate anticoagulation, those with mas- Urokinase was the thrombolytic most frequently adminis- sive parenchymal haemorrhages to minimize the dose of tered (76%). In the majority of cases the thrombolytic was systemic anticoagulation, those with poor prognostic factors locally infused in the occluded sinus (88%). At discharge, on presentation, and finally those where the course is felt to 11 cases (7%; 95% CI 3-12%) were dependent and 9 cases 538 J Pak Med Assoc Table 1. Thrombolytic Therapy for CVT. Venous Flow Restoration Study Therapy Subjects Outcomes and Complication after therapy Wasay, et al 20015 Direct Urokinase vs. N=40 Urokinase group had better dis- Systemic Heparin Urokinase ( n=20) charge neurologic function. Heparin (n=20) No deaths were attributed to either Urokinase or Heparin. Retrospective Comparison Frey, et al 19997 Direct TPA and I.V. N=12 Full in 6/12 partial in 3/12 2/3 failed flow restoration had wors- heparin Case Series Failed in 3/12 ening ICH Pretreatment ICH 3/12 S/SX improved in full and 1/3 tx stopped drop in fbrinogen partial flow Kim & Suh 19978 Direct TPA N=9 Flow restored full 9/9 No haemorrhage or reocclusion Case series Horowitz, et al 19959 Direct Urokinase N=12 Flow restored full in 7/12 No haemorrhage or reocclusion Case Series Partial in 4/12 Pretreatment ICH 4/12 Failed in 1/12 Spearman, et al Direct Urokinase N=2 Flow restored full in 2/2 No haemorrhage or reocclusion 199710 Case report Gartzen, et all 199711 Direct Urokinase fol- N=1 Flow restored No haemorrhage or reocclusion lowed by I.V. heparin Case report Di rocco, et al 198112 Urokinase and heparin N=5 Flow restored in all Full recovery in all Case series in 5% they were associate with clinical deterioration. bolysis group. There were no deaths in either group. At dis- Extracranial haemorrhages occurred in 21%, but only 2% charge, 16 / 20 patients who received urokinase were neuro- required blood transfusion. The mortality rate of 9% is com- logically normal vs. 9 / 20 in those treated with heparin. The parable with that of the European trial with LMWH (9%) long term follow up is not reported. This group concluded and compares favorably with the 7% in the heparin group of that the treatment was at least safe and possibly effective.5 the trial. The following table (Table 1) summarizes some of the case A single retrospective non randomized trial com- series that used thrombolysis for CVST, most show flow pared the outcomes of CVT treated by local urokinase restoration and atleast no increase in mortality with the use administration vs. dose adjusted heparin in 40 patients .The of these agents. patients were well matched for baseline factors , pretreat- Another adjunctive approach that should be dis- ment neurologic function was slightly worse in the throm- cussed in this context is the use of mechanical disruption, Table 2. Mechanical thrombus disruption after incomplete or failed thrombolysis. Venous Flow Restoration Study Therapy Subjects Outcome and complication after therapy Baker et al 200113 Combined pharmalogical N=5 Immediate improvement on Complete recovery N=2/5 (Urokinase/ heparin) and one Urokinase imaging studies N=5/5 Residual neurologic deficit or mechanical (rheolytic and Single intervention N=2/5 N=2/5 ballon catheters) clot disrup- Treatment N=4/5 ton Mechanical disruption alone Two interventions N= 2/5 Significant neurologic deficit N= 1/5 N=1/5 Multiple (5) interventions N=1/5 Chow et al 200014 Mechanical (angiolytic- rhe- N=2 Flow restored full in 2/2 No reported haemorrhage or olytic) thrombectomy with Pretreatment ICH occlusion intra-artrial thrombolysis and Good neurological outcome failed heparin N=2/2 Phillips et al 199515 Peri-thrombus Urokinase N=6 groups Flow restored 6/6 No reported haemorrhage or infusion with mechanical wire Urokinase N=4 occlusion microsnare maceration of Good neurological outcome thrombus Urokinase + mechanical Maceration N=2 Vol. 56, No. 11, November 2006 539 clot maceration and rheolytic suction to aspirate venous and in experienced centers, effective for those with a poor clot. The application of the AngioJet catheter to the treat- prognosis. A large international multicenter trial comparing ment of dural sinus thrombosis has many potential benefits. the two treatments is warranted. First, the AngioJet catheter is one of the few available options when high doses of thrombolytic agents are con- References traindicated. Even locally delivered thrombolytic agents can 1. Bousser MG, Russel RR. Cerebral Venous Thrombosis. In Warlow CP, Van Gijn J,eds .Major Problems In Neurology. London, UK : WB Saunders;1997: require a substantial amount of time to completely lyse a pp 27-29. massive clot; previous studies have documented throm- 2. Ferro JM, Canhão PD, Stam JD; Bousser, MG; Barinagarrementeria F. bolytic infusions of 88 to 244 hours. Because the walls of Prognosis of Cerebral Vein and Dural Sinus Thrombosis.Results of the International Study on Cerebral Vein and Dural Sinus Thrombosis ( ISCVT) the sinuses are thick dura mater, with a low risk of rupture, Stroke. 2004;35:664-70. catheterization of all sinuses with the AngioJet catheter is 3. Vines FS, Davis DO. Clinical and radiological correlation in cerebral venous relatively safe. This is not the case, however, for cerebral occlusive disease. Radiology 1971;98:9-22. veins or the vein of Galen. The walls of these structures are 4. Ciccone A, Canhão P, Falcão F, Ferro JM, Sterzi R.