The role of the lymphatic system in acute arterial prosthetic graft infections.

No experimental data have been published that evaluate the role of lower extremity lymphatics in the pathophysiology of arterial graft infection. Bilateral interpositional femoral artery graft (PTFE) replacements were performed in 21 greyhounds, accompanied by unilateral limb ischemia-rendering operations and ipsilateral bacterial inoculations with standardized inocula of Escherichia coli and Staphylococcus aureus. Inguinal lymphatics in the ischemic leg were either simply transected (group I), carefully preserved (group II), or excised and ligated (group III) at the time of femoral graft implantation. The grafts were harvested 48 hours later and graft and blood cultures obtained. There was an 87.5% incidence of positive graft cultures in groups I and II, but both organisms were cultured significantly more often in group II than in group I (62.5% vs. 12.5%; p less than 0.01). Blood culture data were similar. The incidence of positive graft and blood cultures in group III was only 20%, and no cultures obtained were positive for both organisms. Cultures of contralateral control grafts yielded both organisms in all group II dogs compared with only 25% of group I and 0% in group III (p less than 0.01). These results suggest that the lymphatics probably contribute to the development of acute graft infection by absorbing bacteria, and either transporting them to the systemic circulation via lymphatic-venous communications when the lymphatics are intact, causing hematogenous contamination of a graft, or by directly bathing the implanted graft when the lymphatics are disrupted proximal to a septic focus. Careful isolation, transection, and ligation of the inguinal lymphatics at the time of arterial reconstruction might minimize acute graft sepsis.