Incidence of Subclinical Venous Thromboembolism after Pulmonary Resection for Lung Cancer

Abstract Background Deep venous thrombosis DVT, in post-surgical patients, is more common in lung cancer patients undergoing resection. The combination of malignancy, surgical trauma, chemotherapy, and smoking are all synergistic factors raising the risk. Most of the patients developing post-operative DVT are subclinical and asymptomatic. Subclinical DVT means presence of thrombus in deep veins of lower limb without any signs and symptoms. DVT can be prevented more successfully in its subclinical phase than that in its clinical phase. Aim The present study was undertaken to estimate the occurrence and associated risk factors of subclinical deep vein thrombosis at our institute after lung resection for lung cancer patients in the elective and urgent setting. Methods This is a prospective study of 150 patients who underwent different types of lung resection for lung cancer. Patients younger than 18 years old, symptoms of lower limb DVT and pregnant patients were excluded. Caprini risk score was assessed in all patients. All patients received prophylactic stockings and anticoagulant. On the 5th postoperative day, a duplex venous ultrasound of bilateral lower limbs was performed in every asymptomatic patient to look for presence of thrombus in the deep veins. Results Out of 150 patients enrolled in the study, we completed the study on 147 patients. According to the results of Doppler US, the patients were divided into 2 groups: group 1 (n = 143) post-lung resection and no DVT. Group 2 (n = 4) with post-lung resection subclinical DVT. 4 patients (2.721%) developed subclinical deep vein thrombosis. No patient developed postoperative clinical DVT. Incidence was maximum in the group with longer ICU stay (P-value = 0.04.). Among the various pathologies, incidence was more in patients who received preoperative chemotherapy (P-value = 0.001). One patient (25%) died in the group who developed subclinical DVT while no mortality was observed in the No DVT group. Conclusion It can be concluded that incidence of subclinical deep vein thrombosis is low in the post operative period among the patients undergoing lung resection for lung cancer. However, patients of old age, those with preoperative chemotherapy and those with longer periods of immobilization are at a higher risk to develop postoperative DVT despite anticoagulant prophylaxis. It might be justified to screen these high-risk groups to detect subclinical DVT to allow for post discharge prophylaxis.