Summary
Graft occlusion following peripheral vascular surgery is attributable to some combination
of acute thrombosis, and progression of atherosclerosis: interactions between leukocytes
and activated platelets may play a role in both of these processes. This investigation
measured perioperative leukocyte-platelet conjugate formation, and leukocyte and platelet
activation in 46 patients undergoing surgery for lower extremity peripheral vascular
disease (PVD). All patients were followed for graft patency over the next 6 months;
27 patients had grafts that remained patent while 19 had graft occlusion. On postoperative
day #1 (POD#1), the graft occlusion group demonstrated a significantly greater increase
in circulating levels of both mono-cyteplatelet and neutrophil (PMN)-platelet conjugates
compared to the patent graft patients (p=0.015 and 0.018, respectively). PMN activation, assessed by increases in surface
CD11b expression, was also significantly increased on POD#1 in the graft occlusion
group compared to the patent group (p=0.026). The percentage of circulating activated (CD62P+) platelets did not differ
between groups, but patients with graft occlusion demonstrated a higher percentage
of younger, reticulated platelets throughout the study period (p=0.008), indicating increased platelet turnover.
We conclude that in the early postoperative period, leukocyte-platelet adhesion, PMN
activation, and platelet turnover are significantly greater in PVD patients who go
on to develop later graft occlusion. Cellular activation and heterotypic cell interactions
in peripheral vascular surgery patients may be important in the etiologies of thrombosis
and/or accelerated atherosclerosis leading to graft loss.
Keywords
Cell-cell interactions - clinical/epidemiological studies - platelet activation markers
- vasculopathies