Risks of Catheter-Related Thrombosis in Cancer Patients
Abstract & Commentary
By William B. Ershler, MD, INOVA Fairfax Hospital Cancer Center, Fairfax, VA; Director, Institute for Advanced Studies in Aging, Washington, DC.
Synopsis: In a prospective, observational study from a single institution, consecutive patients with cancer undergoing insertion of a central venous catheter were followed for the occurrence of symptomatic catheter-related thrombosis, symptomatic pulmonary embolus or postphlebitic syndrome. Of the 444 patients enrolled, 19 (4.3%) had symptomatic catheter-related thrombosis and risk factors included more than one insertion attempt, previous central venous catheter insertion, and ovarian cancer. There were no cases of symptomatic pulmonary embolus, and postphlebitic syndrome occurred infrequently.
Source: Lee AY, et al. Incidence, risk factors and outcomes of catheter-related thrombosis in adult patients with cancer. J Clin Oncol. 2006;24:1404-1408.
Oncologists are becoming increasingly comfortable with use of central venous catheters (CVC) particularly for those patients receiving infusional chemotherapy, or who have poor venous access. These have been utilized with a high level of safety and efficacy yet thrombosis remains a concern for its occurrence may result in morbidity or interrupt chemotherapy schedules or transfusions. The purpose of the current report was to examine the incidence, risk factors, and long-term complications of catheter-related thrombosis (CRT) in adults with cancer.
Consecutive patients with cancer who were treated at the Juravinski Cancer Centre in Hamilton, Ontario were enrolled in a prospective, observational study. Patients remained on the study as long as the catheter was in place and for 4 weeks thereafter for a maximum of 52 weeks. Patients with catheter-related thrombosis were followed for an additional 52 weeks from the date of the diagnosed thrombosis. The main end points of the study were symptomatic catheter-related thrombosis, symptomatic pulmonary embolus, postphlebitic syndrome, and catheter lifespan.
Of the 444 patients enrolled, 19 (4.3%) had symptomatic CRT over 76,713 patient days of follow-up. The median time to CRT was 30 days and the median catheter lifespan was 88 days. By multivariate analysis, three significant risk factors became apparent. These were 1) more than one insertion attempt (odds ratio [OR] = 5.5; 95% confidence interval [CI], 1.2-24.6; P = 0.03); 2) ovarian cancer (OR = 4.8; 95% CI, 1.5-15.1; P = 0.01); and, 3) previous central venous catheter insertion (OR = 3.8; 95% CI, 1.4-10.4; P = 0.01). Of the 19 patients with catheter-related thrombosis, 9 were treated with anticoagulants alone, 8 patients were treated with anticoagulants and catheter removal, and two patients did not receive anticoagulation. None of the 19 patients had recurrent CRT or symptomatic PE and postphlebitic symptoms were infrequent.
Thus, the authors concluded that in patients with cancer, the incidence of symptomatic CRT is low and long-term complications are uncommon.
Commentary
This was a rigorous prospective analysis of the incidence of symptomatic CRT in patients with cancer and the results were encouraging. The incidence of symptomatic CRT was low (4.3%) and certain risk factors became apparent. These included difficulty at the time of the insertion, prior central venous catheter, and the presence of ovarian cancer. The low incidence of CRT was similar to that found in other studies although all the methodologies were quite different.1,2
The risk identified in ovarian cancer patients is a curious finding. The investigators carefully reviewed those cases and could find no evidence for specific histologic subtype but did find that these patients were heavily pretreated at the time of CVC insertion and there was a high incidence of poor peripheral venous access in these patients. Thus, it is quite possible that vessel injury from multiple venipunctures and the heavy prior use of cytotoxic chemotherapy were the important contributing factors rather than any specific biological characteristic of the underlying ovarian cancer.
Of note, this study did not find prophylaxis with anticoagulation reduced the risk of symptomatic CRT. However, the authors were quick to point out that this was not the purpose of the current report and the numbers were insufficient to make a confident statement in this regard. Nonetheless, other recent reports have also questioned the value of routine anticoagulant prophylaxis.3,4 Certainly, the published reports to date suggest no therapeutic value for routine or low dose anticoagulation therapy in those with CVC and possibly an increased risk of bleeding.
Thus, in summary, the study demonstrated a low risk of symptomatic catheter-related thrombosis in cancer patients. Although this was from a single institution, the evaluation was thorough and there were a sufficient number of patients to accept the study conclusion with confidence. Because there was a low incidence of symptomatic CRT and because there was no control over type of cancer therapy, anticoagulant prophylaxis and treatment of the CRT, the identification of risk factors was likely to be incomplete and additional studies will be required to confirm those identified and possibly establish others. Nonetheless, we can conclude that symptomatic catheter-related thrombosis is an uncommon occurrence in the general cancer patient population and the risk of symptomatic pulmonary embolus, or even postphlebitic syndrome is very low.
References
1. Verso M, Agnelli G. Venous thromboembolism associated with long-term use of central venous catheters in cancer patients. J Clin Oncol. 2003;21:3665-3675.
2. De Cicco M, et al. Central venous thrombosis: an early and frequent complication in cancer patients bearing long-term silastic catheter. A prospective study. Thromb Res. 1997;86:101-113.
3. Couban S, et al. Randomized placebo-controlled study of low-dose warfarin for the prevention of central venous catheter-associated thrombosis in patients with cancer. J Clin Oncol. 2005;23:4063-4069.
4. Prandoni P, et al. Upper-extremity deep vein thrombosis. Risk factors, diagnosis, and complications. Arch Intern Med. 1997;157:57-62.
Oncologists are becoming increasingly comfortable with use of central venous catheters (CVC) particularly for those patients receiving infusional chemotherapy, or who have poor venous access.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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