Head and neck cancer (HNC) patients who are hospitalized after surgery and do not receive anticoagulation therapy have an increased risk of blood clots, according to a study in JAMA Otolaryngology--Head & Neck Surgery.
However, the patients who received anticoagulation therapy had higher rates of bleeding complications than those who did not get such therapy, noted a research team led by Daniel Clayburgh, MD, PhD, from the Oregon Health and Science University in Portland (September 26, 2103).
Venus thromboembolism (VTE) is a significant cause of postoperative morbidity and mortality following a wide range of surgeries, accounting for about 10% of hospital deaths annually, studies show. Patients who survive VTE are at risk for further complications, including recurrent VTE, pulmonary hypertension, venous stasis, and complications of long-term anticoagulation. In addition, VTE substantially adds to length of hospital stay and costs.
Surgical patients are 20 times more likely to develop VTE, and cancer patients are twice as likely to develop VTE after surgery as patients without cancer, the researchers noted. In fact, VTE may be the most common cause of death in cancer patients following surgery.
Based on this, chemoprophylaxis with anticoagulants such as heparin or fondaparinux is commonly recommended in postsurgical patients. However, VTE chemoprophylaxis has risks. Among HNC patients, complications include bleeding or hematoma that can cause compromised airways, wound complications, or failure of microvascular reconstruction.
Patients undergoing HNC surgery face increased risk for VTE compared with general otolaryngology patients for several reasons, including older age, tobacco use, major surgery, decreased mobility, and decreased pulmonary function.
In this prospective study, Clayburgh and colleagues sought to determine the incidence of VTE following HNC surgery requiring prolonged hospitalization.
Low VTE risk
Retrospective studies of general otolaryngology patients show a very low risk for VTE, between 0.1% and 2.4. Not surprisingly, few HNC surgeons adhere to chemoprophylaxis guidelines.
"Head and neck surgeons have been slower to apply the use of routine postoperative anticoagulation possibly out of fear of bleeding complications," the researchers wrote.
The researchers measured new cases of VTE within 30 days of surgery among patients hospitalized for at least four days. They found an overall incidence of VTE of 13% in a study of 100 HNC patients who were hospitalized and had surgery at their facility, a tertiary care academic medical center in Portland.
Mean patient age was 63.5 years. Most patients had smoked (n = 73, 73%) and had been diagnosed with squamous cell carcinoma (n = 78, 78%).
The patients received perioperative VTE prevention using sequential compression devices (SCDs), but routine chemoprophylaxis was not used. A few days after surgery, the patients got clinical examinations and duplex ultrasonographic (US) evaluation. Patients with negative clinical and US results received clinical follow-up. Patients with deep venous thrombosis (DVT) or pulmonary embolism (PE) received therapeutic anticoagulation. Patients were then monitored for 30 days.
Fourteen patients (14%) received postoperative anticoagulation (excluding patients treated for VTE), and one VTE was observed among them (7% VTE rate). Eight patients experienced bleeding complications among the 100 patients, including four who received anticoagulation (4 of 14, 29%) and four who did not (4 of 86, 5%).
Results
The researchers found an overall VTE incidence rate of 13% (13). Five VTEs were asymptomatic superficial VTEs and deemed clinically nonsignificant. The remaining eight VTEs were judged to be clinically significant (symptomatic superficial VTEs, DVTs, or PEs), yielding a clinically significant VTE rate of 8%.
The researchers noted the study's limitations: Only a small subset of study's patients received pharmacologic prophylaxis. Also, the study group included the highest-risk HNC surgical patients, and the results may not be extrapolated to general otolaryngologists or the treatment of early-state, limited head and neck cancer, the researchers pointed out. Despite the limitations, the study represents the first prospective determination of VTE in HNC surgery patients.
Prospective studies examining the role of VTE chemoprophylaxis should carefully monitor for bleeding complications, the study authors noted.
Conclusion
"Our results support the use of routine VTE chemoprophylaxis in patients with head and neck cancer admitted for more than 72 hours after surgery," the researchers concluded. "Identification of patients at the highest risk of VTE is critical to appropriately directing surveillance and prevention resources."
The findings can be used to establish a baseline VTE rate in high-risk HNC surgery patients that can serve as a benchmark for future prospective trials of VTE chemoprophylaxis, the study authors concluded.
