Effect of timing of perioperative chemical thromboprophylaxis on thromboembolic, bleeding, and other complications during and after antireflux surgery: multicentre cohort study
Authors:   PROTECTinG Investigators and VERITAS Collaborative, Liu David S , Wong Darren J , Goh Su Kah , Watson David I , Wong Enoch , Fong Jonathan , Stevens Sean , Aly Ahmad , Muralidharan Vijayaragavan , Kalogeropoulos George , Liew Chon Hann , Kariyawasam Sanjeeva , Cashin Paul , Mori Krinal , Read Matthew , Bright Tim , Cichowitz Adam , Yeung Justin , Cox Daniel , Holt Jonathon , Jinnaah Sara Mohammed , Crowe Amy , Vu Anh N , Idrees Marwan , Ooi Geraldine , Lee Sharon , Chong Lynn , Downie Emma , Lauritz Brianne , Ashraf Hamza , Maung Hein , Alukaidey Lobna , Wong Samantha , Gill Sonia , Jamel Wael , Reid Caitlin , Elbourne Hugh , Hughes Jed , Doole Emily , Lirios Gabriel , Anandan Manoj , Sankpal Shipra , Zhang Zoe , Larner Brett , Fitt Emily , Paynter Jessica , Chen Nevin , Nasser Ra , Ibrahim Joe , Hilder Amie , Aksakal Gamze , Cheung King Tung , Joglekar Shantanu , Leathersich Amy , Lee Deanna , Lu Thuc Nhi , Qian Wanyang , Palanisamy Vigneshkumar , Rajagopalan Ashray , Menzie Jack , Singh Jasprit , Lim Sean , Su Sandy , Choong Emma , Gray James , Cherry Tiffany , Nadaraja Roshini , May James , McCafferty Jonathan , Lee Jordan , Wilkinson Sally , Choi Cheuk Shan , Ho Felicia Ching Siew , Qiao Jing , Sasanelli Francesca , Bennett Kyle , Fairweather Luke , Zaman Tazvir , Santucci Walter , Jayapadman Vivek 
Published: May 2023

Abstract

Background
Although guidelines recommend the use of perioperative chemical thromboprophylaxis for antireflux surgery, the optimal timing for its initiation is unknown. The aim of this study was to investigate whether perioperative timing of chemical thromboprophylaxis affects bleeding, symptomatic venous thromboembolism, and complication rates in patients undergoing antireflux surgery.

Methods
This study involved analysis of prospectively maintained databases and medical records of all elective antireflux surgeries in 36 hospitals across Australia over 10 years.

Results
Overall, chemical thromboprophylaxis was given early (before surgery or intraoperatively) in 1099 (25.6 per cent) patients, and after surgery in 3202 (74.4 per cent) patients, with comparable exposure doses between the two groups. Symptomatic venous thromboembolism risk was unrelated to chemical thromboprophylaxis timing (0.5 versus 0.6 per cent for early and postoperative chemical thromboprophylaxis respectively (odds ratio (OR) 0.97, 95 per cent c.i. 0.41 to 2.47, P = 1.000). Postoperative bleeding developed in 34 (0.8 per cent) patients, and 781 intraoperative adverse events were identified in 544 (12.6 per cent) patients. Both intraoperative bleeding and complications were associated with significantly higher postoperative morbidity affecting multiple organ systems. Importantly, compared with postoperative chemical thromboprophylaxis, early administration increased the risk of postoperative bleeding ((1.5 versus 0.5 per cent for early and postoperative chemical thromboprophylaxis respectively (OR 2.94, 95 per cent c.i. 1.48 to 5.84, P = 0.002)) and intraoperative adverse events ((16.1 versus 11.5 per cent for early and postoperative chemical thromboprophylaxis respectively (OR 1.48, 95 per cent c.i. 1.22 to 1.80, P &lt; 0.001)), as well as independently predicted their occurrences.

Conclusion
Intraoperative adverse events and bleeding that occur during and after antireflux surgery are associated with significant morbidity. Compared with postoperative chemical thromboprophylaxis, early initiation of chemical thromboprophylaxis confers a significantly higher risk of intraoperative bleeding complications, without appreciable additional protection from symptomatic venous thromboembolism. Therefore, postoperative chemical thromboprophylaxis should be recommended for patients undergoing antireflux surgery.