Is extended pharmacologic venous thromboembolism prophylaxis uniformly safe after radical cystectomy?

Objective To quantitate the risk of clinically significant renal function deterioration after radical cystectomy (RC), which could result in supratherapeutic levels of low-molecular-weight heparin (LMWH) and increased risk of bleeding events with the use of extended pharmacologic venous thromboembolism prophylaxis (EPVTEP) after hospital discharge.

Methods Patients undergoing RC between 2006 and 2011 were identified from the institutional registry. Estimated glomerular filtration rate (eGFR) was calculated and categorized as preoperative, discharge, and nadir. Perioperative eGFR trends in patients who would have been candidates for EPVTEP were evaluated.

Results Three hundred four patients with eGFR >30 mL/min/1.73 m² at the time of hospital discharge were included in the analysis as potentially eligible for EPVTEP. Large portion of patients (43%) exhibited decline in eGFR after discharge. Importantly, 13.0% of patients (n = 40), who would have qualified for EPVTEP at discharge, experienced nadir GFR below the 30-mL/min/1.73 m² threshold value at which LMWH would have become supratherapeutic. The odds ratio for developing a GFR <30 mL/min/1.73 m² was 9.1 (95% confidence interval, 4.3-19.3; P <.001), comparing those with a discharge GFR ≥60 mL/min/1.73 m² with those with a discharge GFR <60 mL/min/1.73 m².

Conclusion More than 10% experienced an eGFR, which would have rendered LMWH supratherapeutic and potentially would have placed the patient at risk for clinically significant bleeding. Although postoperative venous thromboembolic event after RC is a recognized concern, a better understanding of the risks of EPVTEP is needed before this strategy is universally adopted in patients undergoing RC.