Mechanical recanalization for clot occlusion of venous access ports: Experimental study using ports with clot occlusion

Purpose: To test the hypothesis that mechanical injection of saline is safe and effective in restoring patency of totally implantable venous access ports (TIVAPs) with clot occlusion. We devised an experimental port model for the evaluation of mechanical TIVAP recanalization prior to its clinical application. Materials and methods: The clot TIVAP occlusion model was constructed by filling the catheter with swine blood and incubating it at 37.5°C. The model was incubated for different lengths of time ranging from 1 day to 7 days. Each incubation time point included 20 ports. Total catheter occlusion of the TIVAPs was assessed with a 10-mL saline syringe equipped with a non-coring needle. Occlusion was defined as no passage of saline through the catheter when it was aspirated and infused gently with the 10-mL saline syringe. Pressure was evaluated during recanalization with an indeflator. Histological examination was performed on the clot obtained during recanalization. Results: Among the 140 total experimental ports, 65 occlusions (46.4%) were detected. Of these 65 occlusions, 56 (86.1%) were recanalized by mechanical saline pressure via the indeflator. The indeflator pressure ranged from 29 pound per square-inch (psi) to 265 psi at mechanical catheter recanalization (mean: 110 psi). Histologically, all specimens from the model ports exhibited a similar appearance; specifically, erythrocytes, cells, and fibrin were evenly scattered throughout the clot. Conclusions: Our data indicate that it is feasible to generate a TIVAP clot occlusion model with swine blood. Moreover, mechanical recanalization was suitable for resolving occluded catheters without thrombolytic agents.