Catheter-directed thrombolysis, often abbreviated as CDT, is an interventional technique used in select cases of deep vein thrombosis to deliver clot-dissolving medication directly to the site of thrombus rather than relying on the medication traveling through the entire bloodstream. This localized delivery approach was developed to concentrate the drug's effect where it is needed most while aiming to use a lower total systemic dose than intravenous thrombolysis would require.
What Happens During the CDT Procedure?
The procedure begins with percutaneous access into a vein, typically in the leg, followed by advancement of a catheter under imaging guidance until it reaches the location of the thrombus. Once positioned within or adjacent to the clot, the catheter infuses a thrombolytic medication, most commonly tissue plasminogen activator, directly at the treatment site. Unlike a single-session mechanical procedure, this infusion typically continues over an extended period, often ranging from several hours to more than a day, during which the patient remains hospitalized for monitoring.
Why Is the Infusion Delivered Over an Extended Period Rather Than All at Once?
Thrombolytic medications work by activating the body's own clot-dissolving enzyme system, and this process takes time to gradually break down thrombus material. Delivering the medication slowly and directly at the clot site, rather than as a rapid systemic dose, is intended to maximize local drug concentration and effectiveness while limiting the total dose the patient receives, since thrombolytic drugs carry an inherent bleeding risk that increases with higher systemic doses. Physicians monitor patients closely throughout the infusion period, often with repeat imaging to assess clot resolution progress.
What Monitoring Occurs During and After the Procedure?
Patients undergoing CDT are typically monitored in a hospital setting throughout the infusion, with attention to bleeding risk, vital signs, and periodic imaging to track how the clot is responding to treatment. Once thrombolysis has achieved an adequate result, or if imaging suggests residual narrowing, additional interventions such as angioplasty or venous stenting may be considered to address any underlying anatomical issue, such as compression at the iliac vein, that may have contributed to the original clot formation.
What Device Is Used for This Procedure?
The Viper ULTRA Thrombolysis Catheter is described as an ultrasonic pharmacomechanical thrombolysis system that combines targeted ultrasonic energy with controlled thrombolytic drug infusion, intended to support more efficient clot dissolution during catheter-directed treatment. Additional detail on interventional DVT options is available on the deep vein thrombosis products page.
Does CDT eliminate the need for anticoagulation afterward?
No. Anticoagulation is typically continued after catheter-directed thrombolysis to reduce the risk of new clot formation and support long-term vein health. This is a standard part of the overall treatment plan following the procedure.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.