The value of 18 F-FDG PET/CT in diagnosing and localising deep sternal wound infection to guide surgical debridement

Abstract

Deep sternal wound infection (DSWI) is a severe complication in patients after open heart surgery (OHS). But there is a lack of appropriate imaging tool to detect the infection sites, which may lead to incomplete debridement. The present study aims to investigate the value of ¹⁸ F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸ F-FDG PET/CT) in comparison with CT scan in diagnosing and localising DSWI. A total of 102 patients with DSWI after OHS were retrospectively collected from January 2012 to December 2017 in our hospital. All the patients had surgical debridements for DSWI with pretreatment imaging of either ¹⁸ F-FDG PET/CT or CT scan. The sensitivity, specificity, and accuracy of localising infection sites were compared between PET/CT and CT groups, with surgical, microbiological, and histopathological findings as the gold standard. The length of hospital stays and the rate of recurrence were also compared. Ten patients in the PET/CT group had a follow-up PET/CT scan after debridement, and the correlations between the changes of PET/CT findings and surgical outcomes were analysed. ¹⁸ F-FDG PET/CT is more accurate than CT in diagnosing and localising DSWI after OHS, which leads to a more successful surgical debridement with a lower rate of recurrence and a shorter length of hospital stay. In addition, follow-up PET/CT after debridement could evaluate the treatment effect.

Keywords: 18F-FDG; PET/CT; debridement; deep sternal wound infection.

FIGURE 1

A, A 62‐year‐old male had infections in sternum and ribs/costal cartilages who accepted valve surgery 5 years ago. ¹⁸F‐FDG PET/CT showed increased FDG uptake at the infection sites. The maximum standardized uptake value (SUV_max) is 11.5. B, A 58‐year‐old male presented with fistulas and wound separation 5 months after CABG. ¹⁸F‐FDG PET/CT showed infection sites in the sternum and left costal cartilage with increased FDG uptake (SUV_max = 14.1). 3D reconstruction of the sternum and ribs/costal cartilages was performed. CABG, coronary artery bypass grafting; ¹⁸F‐FDG PET/CT, ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography

FIGURE 2

A 72‐year‐old male with DSWI accepted surgical debridement 6 months after CABG. A, The ¹⁸F‐FDG PET/CT 1 week before debridement showed increased uptake in sternum (SUV_max = 7.9) and right fifth costal cartilage (SUV_max = 7.7). B, The follow‐up PET/CT 5 months after debridement showed decreased uptake in sternum (SUV_max = 3.6) and right fifth costal cartilage (SUV_max = 1.6), and new increased uptake at left second (SUV_max = 6.4) and right sixth costal cartilages (SUV_max = 6.2). The patient has recurrent DSWI and resurgery. CABG, coronary artery bypass grafting; DSWI, deep sternal wound infection; ¹⁸F‐FDG PET/CT, ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography

FIGURE 3

A, A 72‐year‐old female with DSWI accepted surgical debridement 2 months after aortic valve replacement. The ¹⁸F‐FDG PET/CT 1 week before debridement showed increased uptake in sternum (SUV_max = 12.6). B, The follow‐up PET/CT 1 year after debridement showed decreased uptake in original infection site (SUV_max = 1.9). The patient has no recurrence. DSWI, deep sternal wound infection; ¹⁸F‐FDG PET/CT, ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography