Effects of different sequences of pulmonary artery and vein ligations during pulmonary lobectomy on blood micrometastasis of non-small cell lung cancer

The aim of this study was to investigate the effects of different sequences of pulmonary artery and vein ligations during lobectomy on blood micrometastasis of non-small cell lung cancer (NSCLC). Cytokeratin 19 (CK19)/adhesion molecule CD44v6 mRNA were used as markers. A total of 30 NSCLC patients undergoing pulmonary lobectomy were randomly divided into pulmonary artery (PA)-first and pulmonary vein (PV)-first groups according to the order of artery or vein ligation (15 cases in each). Fluorescent quantitative-RT-PCR (FQ-RT-PCR) was used to detect the mRNA expression of CK19 and CD44v6 in pulmonary venous blood at the early and late periods during surgery, and ΔCt values were calculated. Meanwhile, the peripheral blood samples from 10 healthy volunteers were selected as the control. ΔCt values of CD44v6 and CK19 of NSCLC groups at the early period during surgery were 7.83±1.70 and 10.76±2.74, while those of the control group were 9.17±1.04 and 12.76±2.36. The expression of CD44v6 and CK19 genes in venous blood of NSCLC groups was significantly higher than that of the control group (P<0.05). In addition, the ΔCt values of CD44v6 and CK19 in the early and late periods during surgery in the PA-first group were 7.92±1.97 vs. 5.67±2.11 (P= 0.008) and 11.21±3.14 vs. 8.60±4.02 (P= 0.05), respectively. The expression of CD44v6 and CK19 in the late period were both significantly higher than those in the early period, while neither the ΔCt value of CD44v6 nor that of CK19 in the early vs. late periods in the PV-first group exhibited statistically significant differences (7.95±1.91 vs. 7.74±2.10 and 10.60±3.15 vs. 10.30±2.98) (P<0.05). Surgical manipulation itself may stimulate the occurrence of blood micrometastasis and the ligation of the PV first during surgery may help prevent blood micrometastasis.