Small Renal Masses and Drug-Eluting Stents — How to Best Balance the Risks?

Answer: Stopping both anti-platelet agents is not without risk even two years following DES insertion, and this risk must be appropriately integrated into decision-making.This patient illustrates the complexity of modern urologic oncology and underscores the limited tools available to quantify...

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Answer: Stopping both anti-platelet agents is not without risk even two years following DES insertion, and this risk must be appropriately integrated into decision-making.

This patient illustrates the complexity of modern urologic oncology and underscores the limited tools available to quantify critical decision-making in routine clinical practice.  A nuanced assessment of competing risks is desired to appropriately counsel this patient. 

Yet, available quantitative tools for these and other trade-offs are limited at best.¹ Drug-eluting stents present a major challenge to today’s surgeons. Stopping dual anti-platelet therapy within 12 months of DES insertion is absolutely contraindicated because extremely high myocardial infarction and mortality rates have been reported.²  The agents that coat DES prevent endothelial cells from covering the stent’s inner surface, resulting in low rates of endothelial restenosis.

Consequently, if anti-platelet agents are stopped, the foreign material of the stent scaffold serves as a nidus for platelet aggregation – especially in the hypercoagulable perioperative state – resulting in acute vessel thrombosis.  Unfortunately, in over 40% of cases, DES do not have protective endothelial covering even three years after stent deployment.²  As such, completely stopping both aspirin and  clopidogrel in patients with remote history of drug-eluting stent placement is not without risk. 

Thus, more and more the mantra of “I can give back blood, but not myocardium” is starting to drive clinical practice at some centers. Accordingly, the patient in the above clinical scenario underwent an uneventful left robot-assisted partial nephrectomy, while on aspirin monotherapy. He was discharged home on post-operative day 2 without requiring a blood transfusion. Pathology demonstrated a 2 cm chromophobe renal cell carcinoma. The patient restarted clopidogrel one week after surgery.

Clearly, robust data regarding appropriate balance of risk with regard to continuing versus stopping anti-platelet therapy in urologic patients with drug-eluting coronary stents who undergo complex surgical procedures are urgently needed.

The case was prepared by Alexander Kutikov, MD, of Fox Chase Cancer Center in Philadelphia.

References

1. Kutikov A, Egleston, BL, Wong YN, et al. Evaluating overall survival and competing risks of death in patients with localized renal cell carcinoma using a comprehensive nomogram. J Clin Oncol 2010;28:311-317.
2. Eberli D, Chassot PG, Sulser T, et al. Urological surgery and antiplatelet drugs after cardiac and cerebrovascular accidents. J Urol 2010;183:2128-2136.