The reasons for improved survival following minimally invasive surgery remain elusive.
Circulating mediators link surgical trauma, vascular and tissue homeostasis. Acute phase reactants,
leukocytes and leukocyte Reactive Oxygen Species (ROS) are affected differentially by minimally invasive
video-assisted thoracic surgery (VATS). Also, immunoglobulins, complement, TNF receptor and P-selectin changes have
been observed, but the influence of minimally invasive surgery on these opsonins is less well defined. In this prospective
randomised trial, 41 patients were randomly assigned to minimally invasive or open thoracic surgery, and immunoglobulins
and vascular endothelial damage biomarkers were analysed. Humoral mediators (blood IgG, IgM, IgA; complement
fragments C3, C4, and complement haemolytic index of activation CH50; TNF receptors I, II and P-selectin) were analysed
before and 2, 5 and 7 days after surgery. Post-surgical changes in individual patients were determined.
Substantial immunoglobulin decreases followed minimally invasive and open surgery. Decreased IgG, IgM and IgE were
detected 2 days after surgery, and IgG and IgM after 7 days. These changes were greater than haemodilution, reaching
greater significance in open surgery patients. Immunoglobulin decreases followed lymphocyte decreases. In contrast, increased
complement and inflammatory endothelial cell signals (C3 and C4, soluble TNFR-II) were detected 7 days after
surgery. In both groups, increased C3 and TNFR-II followed early acute phase reactants CRP, IL-6 and ROS. Acute phase
reactants and CD4/CD8 lymphocytes were factors most attenuated in patients undergoing minimally invasive thoracic
surgery (VATS). This study suggests local trauma mediators are better biomarkers than circulating opsonins in defining
the response to minimally invasive surgery, and a systems approach, comparing individual metabolic responses, is effective
in small patient groups.