SLR - December 2019 - Samantha A. Luer
Reference: Caron A, Depas N, Chazard E, et al. Risk of Pulmonary Embolism More Than 6 Weeks After Surgery Among Cancer-Free Middle-aged Patients. JAMA Surg. Published online October 09, 2019. doi:10.1001/jamasurg.2019.3742Scientific Literature Review
Reviewed By: Samantha A. Luer, DPM
Residency Program: Regions Hospital / HealthPartners Institute – St. Paul, Minnesota
Podiatric Relevance: Surgery is a major transient risk factor of venous thromboembolism (VTE). Prior clinical evidence has demonstrated that the risk of postoperative pulmonary embolism (PE) is highest during the first five weeks after surgery and is also associated with the type of surgery. This is why high-risk patients are usually treated for approximately six weeks after surgery. However, there is little evidence on the continued risk after this time period. The purpose of this study was to assess the duration and the magnitude of late postoperative risk of PE on cancer-free middle-aged patient's by the type of surgery.
Methods: This was a retrospective case-crossover study utilizing the French national inpatient database. The study group included middle-aged adults 45-64 years old who were cancer-free and were admitted to the hospital for the diagnosis of PE from January 1, 2009 to December 31, 2014 after having surgery. The types of surgeries included orthopedic surgery, vascular surgery, gynecological surgery, or gastrointestinal surgery. Orthopedic surgeries were further divided into hip/knee replacements, surgery for fracture and other orthopedic operations.
Chart review was performed to determine the time of PE diagnosis postoperatively. An odds ratio (OR) and its 95 percent CI were computed for each six-week interval postoperatively. The OR reflects the risk of the onset of the primary outcome relative to the baseline risk.
Results: The early risk of PE was elevated during the first six weeks after surgery regardless of the type. Beyond the first six weeks, the risk of late postoperative PE remained elevated for all types of surgery. The highest risk of late postoperative PE was seen in surgeries for orthopedic fractures, with an OR of 4.23 (95 percent CI, 3.01-5.92) between weeks seven to 12 and OR of 2.39 (95 percent CI, 1.65-3.46) between weeks 13-18. The risks of late postoperative PE were lower after orthopedic surgery not related to fractures: between postoperative weeks seven to 12, the OR was 3.64 (95 percent CI, 2.66-4.99) after hip or knee replacement and 2.82 (95 percent CI, 2.20-3.61) after other orthopedic operations. The risk of postoperative PE was not clinically significant beyond 18 weeks post-surgery for all types of procedures.
Conclusions: The current VTE prevention guidelines recommend mechanical prophylaxis, early mobilization, and hydration after all types of surgical procedures. According to these guidelines, the optimal duration of postoperative prophylactic anticoagulation ranges from one to 2 weeks depending on the type of surgery. The extension of prophylaxis for up to five to six weeks is recommended after a major orthopedic procedure or for high-risk patients. In this study, the postoperative risk of PE was found to be elevated for at least 12 weeks after all types of surgery with the greatest risk for orthopedic and vascular surgery. These findings suggest the possible need for longer treatment with prophylactic anticoagulation, but further studies are necessary to define the optimal duration of treatment. At minimum surgical patients should be educated about the signs and symptoms and duration of increased risk for PE.