Local low-dose thrombolysis for safe and effective treatment of venous port-catheter thrombosis.
PURPOSE
Retrospective evaluation of local low-dose thrombolysis for treatment of venous port-catheter thrombosis.


METHODS
A total of 1,031 patients with dysfunctional port systems underwent port angiography depicting 181 patients with thrombosis around the port-catheter. A total of 165 patients (male 35, female 130; age 57.3 ± 12.9 [20-83] years) underwent thrombolysis by single injection of 3 mg alteplase into the port system. Patients were followed up by clinical and angiographic/radiological port controls the next day and 12.9 ± 17.9 [1-81] months on the basis of regular oncologic staging examinations.


RESULTS
Thrombosis occurred 10.1 ± 19.3 [median 2.9] months after port implantation and was clinically suspected by difficult blood aspiration in 146 of 181 (80.7 %) and high resistance to injection fluids in 75 (41.4 %) patients. A predictor for angiographically confirmed port-catheter thrombosis was a combination of both (73, 40.3 % patients) (Fisher's exact test p < 0.0001; positive predictive value 0.8977), or suboptimal (not cavoatrial) port-catheter position (92, 50.8 % patients) (p = 0.0047; positive predictive value 0.8276). The cumulative success rate of thrombolysis was 92.7 % (153 of 165 patients). Initial thrombolysis was effective in 127 (77.0 %) patients. Repeated (up to 6 times) thrombolysis was effective in 26 of 31 patients after second or third thrombolysis. Extensive central venous thrombosis (9 patients) predicted ineffective thrombolysis (p < 0.0001). Primary patency of successfully treated devices was 92.8 % at 1 month and 84.9 % at 3 months. Rethrombosis occurred in 27 patients after 4.4 ± 6.6 (median 1.8) months. Primary rethrombolysis was effective in 22 (81.5 %) patients. Cumulative patency was 100 % at 3 months.


CONCLUSIONS
Difficult aspiration combined with high resistance to injection fluids or suboptimal port-catheter position are strong independent predictors for port-catheter thrombosis. Local low-dose thrombolysis or repeat thrombolysis is safe and effective in the absence of large central venous thrombosis.