Pre‐operative and intra‐operative chemical thromboprophylaxis increases bleeding risk following elective cholecystectomy: a multicentre (PROTECTinG) study

Abstract

Background: Cholecystectomy is commonly performed in general surgery. Despite guidelines recommending chemical thromboprophylaxis in the perioperative period, the most appropriate time for its initiation is unknown. Here, we investigated whether timing of chemoprophylaxis affected venous thromboembolism (VTE) and bleeding rates postcholecystectomy. Methods: Retrospective review of all elective cholecystectomies performed between 1 January 2018 and 30 June 2019, across seven Victorian hospitals. Clinical VTE was defined as imaging-proven symptomatic disease within 30 days of surgery. Major bleeding was defined as the need for blood transfusion, surgical intervention or >20 g/L fall in haemoglobin from baseline. Results: A total of 1744 cases were reviewed. Chemoprophylaxis was given early (pre-or intra-operatively), post-operatively or not given in 847 (48.6%), 573 (32.9%) and 324 (18.6%) patients, respectively. This varied significantly between surgeons, fellows, trainees and institutions. Clinical VTE occurred in 5 (0.3%) patients and was not associated with chemoprophylaxis timing. Bleeding occurred in 42 (2.4%) patients. Of this, half were major events, requiring surgical control in 5 (11.9%) patients and blood transfusion in 9 (21.4%) patients. Bleeding also extended length of stay (mean (SD), 3.1 (4.0) versus 1.4 (2.2) days, P < 0.001). One bleeding-related mortality was recorded. Importantly, when compared with post-operative (risk ratio 1.46, 95% confidence interval 1.21-1.62) and no (RR 1.23, 95% CI 1.03-1.35) chemoprophylaxis, early usage significantly increased bleeding risk and independently predicted its occurrence. Conclusions: Perioperative chemoprophylaxis is variable among patients undergoing elective cholecystectomy. The rate of clinical VTE post-cholecystectomy is low. Early chemoprophylaxis increases bleeding risk without an appreciable additional protection from VTE.

Variations in practice of thromboprophylaxis across general surgical subspecialties: a multicentre (PROTECTinG) study of elective major surgeries

“…Unfortunately, such an approach can lead to inadequate protection against VTE or increase post-operative bleeding risk. 4 In this study, we extend the observations made from our multicentre survey by quantifying the heterogeneity of perioperative thromboprophylaxis across all major general surgical operations, and placing them in context of their bleeding and VTE risk. Findings from this study will highlight areas of practice with the greatest variability, allow surgeons to benchmark their practices against that of their colleagues and focus future research to optimize perioperative thromboprophylaxis.…”

“…Variable use of chemoprophylaxis was most commonly seen in surgeries on the neck, breast, gall bladder and ventral hernias. This may be explained by their inherently low but not absent VTE risk, their relatively higher although not exceedingly high rate of postoperative bleeding, [4][5][6][7] discrepant literature which encourages yet questions the need for chemoprophylaxis, 8 confusing guidelines which broadly recommends chemoprophylaxis without accounting for individual risks 2 and a fear of litigation which may influence decision-making. 9 Importantly, chemoprophylaxis use has been associated with increased bleeding in these operations.…”

“…9 Importantly, chemoprophylaxis use has been associated with increased bleeding in these operations. 4,6,7 Notably, bleeding risk post thyroid/parathyroid surgeries significantly outweighs that of VTE in most patients. 6 Taken together, these findings highlight the need to refine guidelines for these commonly performed operations.…”

“…3 Importantly, inappropriately timed chemoprophylaxis may contribute to increased bleeding and mortality. 4,11 These findings emphasize the need to further examine how timing of chemoprophylaxis impacts surgical outcomes, particularly for operations on the gastrointestinal system, where bleeding and VTE risks are high.…”

Perioperative thromboprophylaxis is highly variable in general surgery: results from a multicentre survey

“…For example, in patients undergoing elective cholecystectomies, early chemoprophylaxis has been associated with increased rates of bleeding compared with its post-operative usage. 5 Moreover, findings from the Victorian Audit of Surgical Mortality identified that inappropriate use of thromboprophylaxis repeatedly contributed to surgical mortality. 6 Chemoprophylaxis requires balancing the risk of bleeding with thromboembolic protection.…”