What is the recommended approach for chemical thrombolysis in superior sagittal sinus thrombosis?

Chemical Thrombolysis in Superior Sagittal Sinus Thrombosis

Chemical thrombolysis should be reserved for severe cases of superior sagittal sinus thrombosis (SSST) with neurological deterioration despite anticoagulation, as it carries higher bleeding risks compared to standard anticoagulation therapy. 1

First-Line Treatment: Anticoagulation

• Initial management of SSST should begin with therapeutic anticoagulation using low molecular weight heparin (LMWH) or unfractionated heparin (UFH) immediately upon diagnosis 1
• Anticoagulation is recommended even in the presence of intracranial hemorrhage, as the benefits of preventing thrombus progression outweigh bleeding risks 1
• Anticoagulation should be continued for at least 3 months (treatment phase) 1

Indications for Chemical Thrombolysis

• Consider chemical thrombolysis only when patients show:
  • Rapid neurological deterioration despite adequate anticoagulation 2, 1
  • Extensive thrombus burden with signs of increased intracranial pressure not responding to medical management 1
  • Coma or impending herniation due to venous infarction or edema 1

Chemical Thrombolysis Approach

• Direct endovascular thrombolysis involves catheter-directed delivery of thrombolytic agents directly into the thrombosed sinus 2
• Common thrombolytic agents include:
  • Urokinase (historical agent) 3, 4
  • Tissue plasminogen activator (tPA) 3
• Access routes:
  • Retrograde approach: Most common, via internal jugular vein 2
  • Antegrade approach: Via burr hole access, considered when retrograde access fails 5

Efficacy and Safety Considerations

• Non-randomized studies suggest that local thrombolysis may be more effective than systemic anticoagulation alone for severe SSST 4
• Hemorrhagic complications occur in approximately 10% of patients undergoing chemical thrombolysis 4
• Chemical thrombolysis has shown 90% success in restoring sinus patency, but with 30% risk of hemorrhagic complications 6

Combined Approaches

• Mechanical thrombectomy combined with chemical thrombolysis may provide better outcomes with lower hemorrhagic risk 6
• Techniques include:
  • Balloon angioplasty for mechanical disruption of thrombus 7
  • Rheolytic thrombectomy devices 5
  • Combination of mechanical thrombectomy with local thrombolytic infusion 6

Monitoring During Thrombolysis

• Continuous neurological assessment is essential during the procedure 1
• Serial imaging (CT or MRI) should be performed to monitor for hemorrhagic complications 2
• Venographic confirmation of recanalization should guide the duration of thrombolytic therapy 2

Post-Thrombolysis Management

• Following chemical thrombolysis, patients should be transitioned to systemic anticoagulation 4, 6
• Follow-up imaging (MRV or CTV) should be performed to assess recanalization 1
• Monitor for signs of post-thrombotic syndrome 1

Clinical Decision Algorithm

1. Confirm diagnosis with MRI/MRV or CT/CTV 1
2. Initiate therapeutic anticoagulation with LMWH or UFH 1
3. Monitor neurological status closely 1
4. If deterioration occurs despite anticoagulation, consider:
   • Repeat imaging to assess thrombus progression 2
   • Consult neurointerventional team for possible chemical thrombolysis 1
5. If chemical thrombolysis is performed:
   • Use direct catheter-based approach 2
   • Consider combined mechanical and chemical techniques 7, 6
   • Monitor closely for hemorrhagic complications 4, 6
6. Resume anticoagulation after thrombolysis 4, 6

Chemical thrombolysis remains a specialized intervention that should be performed at centers with expertise in neurointerventional procedures and management of cerebral venous thrombosis 1, 6.