Guideline of guidelines: thromboprophylaxis for urological surgery Philippe D. Violette*, Rufus Cartwright †‡ , Matthias Briel § , Kari A.O. Tikkinen ¶ and Gordon H. Guyatt** ,†† *Division of Urology, Department of Surgery, Woodstock Hospital, Woodstock, ON, Canada, † Department of Epidemiology and Biostatistics, Imperial College London, London, UK, ‡ Department of Urogynaecology, St. Mary’s Hospital, London, UK, § Institute for Clinical Epidemiology and Biostatistics, Department of Clinical Research, University Hospital Basel, Basel, Switzerland, ¶ Departments of Urology and Public Health, University of Helsinki and Helsinki University Hospital, Helsinki, Finland, **Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada, and †† Department of Medicine, McMaster University, Hamilton, ON, Canada Decisions regarding thromboprophylaxis in urologic surgery involve a trade-off between decreased risk of venous thromboembolism (VTE) and increased risk of bleeding. Both patient- and procedure-specific factors are critical in making an informed decision on the use of thromboprophylaxis. Our systematic review of the literature revealed that existing guidelines in urology are limited. Recommendations from national and international guidelines often conflict and are largely based on indirect as opposed to procedure-specific evidence. These issues have likely contributed to large variation in the use of VTE prophylaxis within and between countries. The majority of existing guidelines typically suggest prolonged thromboprophylaxis for high-risk abdominal or pelvic surgery, without clear clarification of what these procedures are, for up to 4 weeks post-discharge. Existing guidance may result in the under- treatment of procedures with low risk of bleeding and the over-treatment of oncological procedures with low risk of VTE. Guidance for patients who are already anticoagulated are not specific to urological procedures but generally involve evaluating patient and surgical risks when deciding on bridging therapy. The European Association of Urology Guidelines Office has commissioned an ad hoc guideline panel that will present a formal thromboprophylaxis guideline for specific urological procedures and patient risk factors. Keywords anticoagulation, bleeding, deep vein thrombosis, prophylaxis, pulmonary embolism, venous thromboembolism Introduction The risks and benefits of thromboprophylaxis for urological surgery depend on both patient-specific and procedure- specific factors [1,2]. Clinicians and patients must trade off a reduction in venous thromboembolism (VTE) against a potential increase in bleeding. Although investigators have not addressed the issue specifically for urological procedures, high-quality evidence from randomized trials has shown that pharmacological prophylaxis, with, for example, low- molecular-weight heparins (LMWH), decreases the risk of VTE in patients undergoing abdominal or pelvic surgery by ~50% [1]. Best estimates for LMWH also suggest, however, an increase in the risk of postoperative major bleeding of ~50% [1]. Although these relative risks are likely to be consistent across patients and procedures, the balance of benefits and harms varies with the absolute risk of VTE and bleeding. In patients with a high risk of VTE and a low risk of major bleeding, a 50% reduction in VTE represents a substantial benefit (for instance, from a baseline risk of 12 to 6%) and a 50% increase in bleeding represents a minimal increase in harm (for instance, from 0.2 to 0.3%). Patients whose risk of VTE without anticoagulation is low and whose bleeding risk is high face the opposite situation. Because evidence regarding procedure- and patient-specific baseline risks of thrombosis and bleeding in the absence of prophylaxis remains very limited, decisions regarding the use of VTE prophylaxis currently involve large uncertainty [1,3]. The existence of substantial practice variation in the use of thromboprophylaxis in urology, both within and among countries, is therefore not surprising [4–6]. In this context we have summarized, taking a global perspective, the available guidelines addressing the use of thromboprophylaxis in urology. Methodology We performed a Medline search of the period from 1 January 2000 until 31 December 2015 and, in addition, manually searched the websites of international and national urological © 2016 The Authors BJU International © 2016 BJU International | doi:10.1111/bju.13496 BJU Int 2016; 118: 351–358 Published by John Wiley & Sons Ltd. www.bjui.org wileyonlinelibrary.com Guidelines