Aortic Vascular Graft and Endograft Infection-Patient Outcome Cannot Be Determined Based on Pre-Operative Characteristics

Abstract

Vascular graft/endograft infection (VGEI) is a serious complication after aortic surgery. This study investigates VGEI and patient characteristics, PET/CT quantification before surgical or conservative management of VGEI and post-intervention outcomes in order to identify patients who might benefit from such a procedure. PET standard uptake values (SUV) were quantitatively assessed and compared to a non-VGEI cohort. The primary endpoints were in-hospital mortality and aortic reintervention-free survival at six months. Ninety-three patients (75% male, 65 ± 10 years, 82% operated) were included. The initial operation was mainly for aneurysm (67.7%: 31% EVAR, 12% TEVAR, 57% open aortic repair). Thirty-two patients presented with fistulae. PET SUV_TLR (target-to-liver ratio) showed 94% sensitivity and 89% specificity. Replacement included silver-coated Dacron (21.3%), pericardium (61.3%) and femoral vein (17.3%), yet the material did not influence the overall survival (p = 0.745). In-hospital mortality did not differ between operative and conservative treatment (19.7% vs. 17.6%, p = 0.84). At six months, 50% of the operated cohort survived without aortic reintervention. Short- and midterm morbidity and mortality remained high after aortic graft removal. Neither preoperative characteristics nor the material used for reconstruction influenced the overall survival, and, with limitations, both the in-hospital and midterm survival were similar between the surgically and conservatively managed patients.

Keywords: aortic graft infection; pericardial prosthesis; silver graft; vascular graft endograft infection.

Figure 1

Patient flow chart.

Figure 2

Positron emission tomography (PET)/CT and sensitivity/specificity analysis. (A) Axial and coronary depiction of PET/CT overlay and PET scan with correspondingly marked region of interest (ROI; red circle) where mean standard uptake value (SUV) is measured. Additional measurements are made in the liver (B) and the ascending aorta (mediastinal blood pool) (C). (D) Receiver-operator curve (ROC) for sensitivity/specificity based on area under the curve (AUC) measurement for SUV_max aorta, SUV_TBR and SUV_TLR. (SE = standard error; CI = confidence interval; cut-off at maximum sensitivity and specificity).

Figure 3

Outcome analysis. (A) The overall survival is shown as a Kaplan–Meyer plot comparing operative and conservative treatments for the entire vascular graft and endograft infection (VGEI) cohort (N = 93). (B) The overall survival is shown for the three different vascular substitutes used in the abdominal replacement group (N = 64) (log-rank test for comparison; p < 0.05 is considered significant).

Figure 4

Forest plot shows selected univariate odds ratios for in-hospital mortality, with 95% confidence intervals and p values (logistic regression and Wald test; p < 0.05 is considered significant and highlighted bold; all values shown in Supplementary Table S5).