Speaker
Paul J. Karanicolas, MD, PhD, FRCSC
Associate Professor of Emergency Medicine and Epidemiology
The Edmond Odette Cancer Centre @ Sunnybrook Health Sciences Centre
Professor of Surgery
University of Toronto
Keywords
Liver Cancer; Liver Resection; Blood Transfusions
Key Points
- Liver resection is a major operation. Though it’s become safer over the past several decades, it requires blood transfusion in 20-40% of patients. Bleeding and blood transfusion are associated with substantial post-operative morbidity and an increase in mortality, re-operation, and re-admission rates.
- A 2012 meta-analysis found that tranexamic acid (TXA) use in surgery was associated with lower blood transfusion rates. However, most of the trials included in the analysis involved cardiac and orthopedic surgery. There was limited evidence to suggest that TXA offered similar protective effects for liver resection patients.
- The research team designed a pragmatic trial of adult patients undergoing cancer-related liver resection. Their primary outcome was the receipt of blood transfusion over the first seven days during or following surgery.
- They randomized 1,384 participants to either a TXA arm or a placebo arm over eight years. They found that administration of TXA had no impact on blood transfusion, interoperative bleeding, or total blood loss; however, it increased the incidence of any surgical complications and major adverse events, with a possible increase in venous thromboembolism (VTE).
- These findings were discordant with most existing evidence. Possible explanations included chance (unlikely, given the narrow confidence interval); a differing mechanism of bleeding in liver resection patients; and a difference in the dose or timing of TXA (also unlikely).
- Based on this trial, the study team concluded that 1) TXA does not reduce blood transfusion or bleeding in patients undergoing liver resection; 2) TXA increases adverse events in this context with a signal towards increased VTE; and 3) TXA should not be used routinely in patients undergoing liver resection.
- More work is necessary to determine whether TXA is beneficial and safe in other types of major oncologic surgery.
Discussion Themes
After some debate, the research team designed their trial to include all liver resection patients as opposed to only patients receiving major liver resections. Only 1/3 of patients have a major operation, and all liver resection patients have at least a 15% risk for bleeding and blood transfusion.
They landed on receipt of blood transfusion as the primary outcome because of the strong association between transfusion and other patient-important outcomes and due to the limited nature of blood transfusions as a resource.
Dr. Karanicolas reflected that the team should have collected adverse events data differently, grouping the complications into more meaningful categories; currently, they are limited in their ability to interpret the complications data.
The study team intentionally did not build an efficacy stopping rule into the trial due to concerns about bias. Having seen the trial through to the end, they had stronger evidence when they arrived at their surprising conclusion.