The clinical impact of ultrasound contrast agents in EUS: a systematic review according to the levels of evidence.
OBJECTIVE
The use of contrast-harmonic EUS (CH-EUS) in routine clinical practice is increasing rapidly but is not yet standardized. We present the levels of evidence (LEs) found in the literature to put its clinical outcomes in the appropriate perspective.


METHODS
We conducted a systematic review of the available English-language articles. The LEs were stratified according to the Oxford Centre for Evidence-Based Medicine guidelines.


RESULTS
Overall, 210 articles were included and presented according to different pathologic conditions. For pancreatic solid neoplasms, the pooled sensitivity and specificity in the diagnosis of pancreatic carcinoma were very high (LE 1); quantitative analysis and guidance of FNA were reported as investigational research (LE 2-3). For pancreatic cystic lesions, the identification of neoplastic solid components as hyperenhanced lesions represented a promising application of CH-EUS (LE 2). For lymph nodes, CH-EUS increased the diagnostic yield of B-mode EUS for the detection of malignancy (LE 2). For submucosal tumors, CH-EUS seemed useful for differential diagnosis and risk stratification (LE 2-3). For other applications, differential diagnosis of gallbladder and vascular abnormalities by CH-EUS were reported (LE 2-3).


CONCLUSIONS
The LEs of CH-EUS in the literature have evolved from the initial descriptive studies to multicenter and prospective trials, and even meta-analyses. The differential diagnosis between benign and malignant lesions is the main field of application of CH-EUS. With regard to pancreatic solid neoplasms, the concomitant use of both CH-EUS and EUS-FNA may have additive value in increasing the overall accuracy by overcoming the false-negative results associated with each individual technique. Other applications are promising but still investigational.
Gastroenterology Unit, Hospital of Imola, University of Bologna, Bologna, Italy.
Pietro
P
Fusaroli
Department of Gastroenterology, Private Hospital Jean Mermoz, Lyon, France.
Bertrand
B
Napoleon
Department of Gastroenterology, Private Hospital Jean Mermoz, Lyon, France.
Rodica
R
Gincul
Department of Gastroenterology, Private Hospital Jean Mermoz, Lyon, France.
Christine
C
Lefort
Trocadero Clinic, Paris, France.
Laurent
L
Palazzo
Trocadero Clinic, Paris, France.
Maxime
M
Palazzo
Department of Gastroenterology and Hepatology, Kinki University Faculty of Medicine, Osaka-Sayama, Japan.
Masayuki
M
Kitano
Department of Gastroenterology and Hepatology, Kinki University Faculty of Medicine, Osaka-Sayama, Japan.
Kosuke
K
Minaga
Gastroenterology Unit, Hospital of Imola, University of Bologna, Bologna, Italy.
Giancarlo
G
Caletti
Gastroenterology Unit, Hospital of Imola, University of Bologna, Bologna, Italy.
Andrea
A
Lisotti
D003287:Contrast Media; D019160:Endosonography / Q000379:methods*; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D010181:Pancreatic Cyst / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging*
D003287:Contrast Media