Cardiovascular Surgery, Vol. 5, No. 5, pp. 486–489, 1997  1997 The International Society for Cardiovascular Surgery Published by Elsevier Science Ltd. Printed in Great Britain 0967–2109/97 $17.00 + 0.00 PII: S0967-2109(97)00056-2 Mechanism of late prosthetic vascular graft infection L. Jones, B. D. Braithwaite, B. Davies, B. P. Heather and J. J. Earnshaw Department of Surgery, Gloucestershire Royal Hospital, Gloucester, UK This study was a retrospective analysis of 41 patients with late prosthetic graft infections (> 30 days after operation) from six hospitals in the south-west of England. The 41 patients had a median age of 66 years and generally accepted risk factors for infection were documented in 19 patients preoperatively. Thirteen patients had postoperative wound complications and three had early reoperation at the site of subsequent infection. The median time between index operation and symptoms of infection was 10 (range 1–224) months. Abscess (46%) was the most common presentation followed by false aneurysm (20%) and graft thrombosis (20%). All patients had reoperations (median two per patient, range one to seven). Seven (17%) patients died and 10 (24%) required a major amputation. Bacteria were isolated from retrieved grafts in 23/41 patients (high virulence 14, low virulence nine) and the most frequent organism was coagulase-negative Staphylococcus epidermidis (nine patients). In the majority of cases the aetiology of the late infections in this series was consistent with bacterial implan- tation at the index operation, but in four cases bacteraemia or intraperitoneal spread was more likely. Dental-type antibiotic prophylaxis would not have prevented any of the infections in this study. Aggressive treatment of recognized sources of infection in patients with vascular grafts is imperative.  1997 The International Society for Cardiovascular Surgery Keywords: vascular reconstruction, surgical complications, graft infection, antibiotic prophylaxis Graft infection is a rare but catastrophic compli- cation of vascular surgery with mortality rates described from 12–33% and amputation rates of 19– 53% [1–3]. The reported incidence varies from 0– 8% [1–5]. The incident rate has probably been reduced by perioperative systemic antibiotic prophy- laxis, but the overall prevalence is increasing in paral- lel with the expansion in vascular reconstructive sur- gery. The infection rate depends on the site of reconstruction and the graft material used. Graft infection rates are highest for synthetic extra-ana- tomic grafts and lowest following intra-abdominal aortic surgery and venous grafts [1–3]. Approxi- mately 50% of graft infections occur as a result of direct contamination from a groin wound infection and these were excluded from this study [1, 5]. There is no accepted definition of late graft infection; Correspondence to: Mr J. J. Earnshaw, Gloucestershire Royal Hospi- tal, Great Western Road, Gloucester GL1 3NN, UK CARDIOVASCULAR SURGERY OCTOBER 1997 VOL 5 NO 5 486 all patients in this study had complete initial healing of their surgical wounds. Infection became apparent a minimum of 1 month later. The aetiology of late vascular graft infection is said to be implantation of bacteria at the time of initial surgery, but in a few cases infection may result from seeding onto the graft during a bacteraemia. This study is a retrospective review of the bacteriology of late graft infection (>30 days after operation) in the south-west region of England. Patients and methods Using local computer vascular registries from six hospitals in the south-west of England, 41 patients were identified who had presented with a prosthetic graft infection >30 days after vascular surgery. There were 30 men and 11 women with a median age of 66 (range 44–85) years. All developed late graft infection between June 1978 and October 1994. The