Introduction: So far, there has been no report addressing the actual rate of asymptomatic pulmonary embolism (PE). The present study was conducted to clarify the incidence and the characteristics of postoperative PE including asymptomatic cases in gynecologic oncology.

Methods: A total of 2107 gynecologic surgery cases that were performed from January 1996 to December 2006 at the National Kyushu Cancer Center were included. Pulmonary embolism was diagnosed using a lung scan, multi-detector row computed tomography, or pulmonary angiography. The clinical factors, including prophylaxes, were analyzed by univariate and multivariate analyses.

Results: PE was diagnosed in 45 patients (2.14%). Six (13.3%) of the 45 patients had respiratory symptoms or signs, and 16 patients (35.6%) had no symptoms or signs except for a SpO₂ level decrease. PE was diagnosed within 4 days after the surgery in 42 patients (93.3%). There were 1 massive, 2 recurrent, and no fatal PEs. A multivariate analysis demonstrated the incidence of PE to be associated with age (odds ratio, 1.957; 95% confidence interval, 1.497-2.559), operation time (1.664; 1.180-2.346), body mass index (2.457; 1.735-3.479), surgical position (2.253; 1.468-3.458), and the use of a perioperative intermittent pneumatic compression device (0.389; 0.229-0.659).

Conclusions: A substantial number of postoperative PEs were occult, and identification of high-risk patients and routine SpO₂ level monitoring would reduce the diagnostic delay of PE after gynecologic surgery. Increasing age, longer operation time, and obesity were risks. The use of a perioperative intermittent pneumatic compression device in multimodal conditions might thus prevent PE.