Correlation Found between Increased VTE Risk and Short-Haul Air Travel after TJA
New research presented at the 2018 Annual Meeting of the American Academy of Orthopaedic Surgeons reports a correlation between flying following hip or knee arthroplasty and an increased risk of venous thromboembolism (VTE). This is the first study to identify such a risk, as previous studies found no additional risk from perioperative air travel in patients following lower-limb joint replacement surgery.
The retrospective cohort study reviewed the records of patients who underwent lower-limb joint replacement surgery at a high-volume, national arthroplasty unit at the Golden Jubilee National Hospital in Glasgow, Scotland, between 2013 and 2015. The hospital services a large geographic area that includes several remote islands, which requires patients to fly to and from the hospital for surgery. The researchers compared outcomes in 2 groups of patients:
- Those who traveled by air to and from the hospital
- Those who traveled by land
Per hospital guidelines, all patients received pharmacologic and mechanical thromboprophylaxis.
“Despite flying our patients in for treatment for many years, we hadn’t explored whether this difference was present prior to the study,” said Fahd Mahmood, clinical research fellow at the Golden Jubilee National Hospital, Glasgow, Scotland.
“Our event rate, especially in the flight group, was quite small, so we didn’t pick up that there was a higher rate of VTE from our routine practice. However, when we looked at the data, the difference was there. Of the previous studies that looked at preoperative or postoperative flying, none have demonstrated an increased risk. Our study was significantly larger, though the length of our flights was shorter.”
A total of 243 patients flew at a mean of 6 days following arthroplasty (range 1 to 24 days) during the 3-year study period; there were 5,498 patients in the control group. The mean flight time was 74 minutes (range 40 to 85 minutes). Four patients (1.64%) developed a VTE in the flight group (2 pulmonary emboli, 2 deep vein thromboses). Thirty-two patients (0.58%) developed a VTE in the control group (25 pulmonary emboli, 7 deep vein thromboses).
“We don’t quite understand the mechanisms behind why there is an increased risk of VTE with flying, but there are a number of hypotheses,” said Mahmood. “This study demonstrates that there is an association between flying and an increased risk of VTE, but we can’t demonstrate causality.
“Based on the data we have at the moment, we can counsel our patients that if they are flying to and from the institution, we think there may be an increased risk of blood clots, but we need more evidence.”
Mahmood F, Harte C, Allen D, Picard F, Clarke J. Flying in the Early Postoperative Period following Lower Limb Arthroplasty – Is It Safe? (Paper 772). Presented at the 2018 Annual Meeting of the American Academy of Orthopaedic Surgeons, March 6-10, 2018, New Orleans, Louisiana.