Systematic reviews of observational studies of risk of thrombosis and bleeding in urological surgery (ROTBUS): introduction and methodology

Abstract

BackgroundPharmacological thromboprophylaxis in the peri-operative period involves a trade-off between reduction in venous thromboembolism (VTE) and an increase in bleeding. Baseline risks, in the absence of prophylaxis, for VTE and bleeding are known to vary widely between urological procedures, but their magnitude is highly uncertain. Systematic reviews and meta-analyses addressing baseline risks are uncommon, needed, and require methodological innovation. In this article, we describe the rationale and methods for a series of systematic reviews of the risks of symptomatic VTE and bleeding requiring reoperation in urological surgery.Methods/designWe searched MEDLINE from January 1, 2000 until April 10, 2014 for observational studies reporting on symptomatic VTE or bleeding after urological procedures. Additional studies known to experts and studies cited in relevant review articles were added. Teams of two reviewers, independently assessed articles for eligibility, evaluated risk of bias, and abstracted data. We derived best estimates of risk from the median estimates among studies rated at the lowest risk of bias. The primary endpoints were 30-day post-operative risk estimates of symptomatic VTE and bleeding requiring reoperation, stratified by procedure and patient risk factors.DiscussionThis series of systematic reviews will inform clinicians and patients regarding the trade-off between VTE prevention and bleeding. Our work advances standards in systematic reviews of surgical complications, including assessment of risk of bias, criteria for arriving at best estimates of risk (including modeling of timing of events and dealing with suboptimal data reporting), dealing with subgroups at higher and lower risk of bias, and use of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate certainty in estimates of risk. The results will be incorporated in the upcoming European Association Urology Guideline on Thromboprophylaxis.Systematic review registrationPROSPERO CRD42014010342.Electronic supplementary materialThe online version of this article (doi:10.1186/2046-4053-3-150) contains supplementary material, which is available to authorized users.

Guideline of guidelines: thromboprophylaxis for urological surgery

“…These guidelines will be based on a series of systematic reviews that evaluate the baseline risk of thrombosis and bleeding in urological surgery (ROTBUS) [3]. Such assessments are challenging to perform but will result in the best available estimates of VTE and bleeding risk, from which informed decisions about prophylaxis can be made.…”

“…This statement has a number of limitations: optimum dosing regimens and treatment duration are not well defined, and the document deals mainly with inhospital prophylaxis only. Because the majority of thromboembolic events occur after discharge, in-hospital prophylaxis will have limited impact in reducing VTE risk [3,[18][19][20]. Similarly, the estimated risks of VTE and bleeding reported in the AUA Best Practice statement may be misleading, first because guidance was not informed by evidence-based knowledge synthesis, and secondly because they may not reflect current practice because of advances in surgical technique and care [21][22][23].…”

“…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][5][6].…”

Venous thromboembolism prophylaxis in cancer patients — guidelines focus on surgical patients

“…On the other hand, application of minimally invasive techniques reduced incidence of thromboembolic complications but did not eliminate them entirely, whereas pulmonary embolism remained to be the most common nonsurgical cause of death in this group [14,180]. Like in the other surgical specialties, assessment of VTE risk and bleeding risk is crucial for the proper qualification for antithrombotic prophylaxis [14,180,225]. Because of the fact that there are no studies referring to the particular clinical situations (the same type of surgery, same bleeding risk and VTE risk) of sufficient quality, individual approach and treatment in each patient is encouraged.…”

“…In endoscopic urologic surgeries as well as in open surgery, bleeding risk assessment is significant for the proper an safe thromboembolism prophylaxis implementation [225,243]. In this context, in the patients with elevated bleeding risk mechanical prophylaxis methods, such as intermittent pneumatic compression are of special interest.…”