Criteria for the selective use of contrast-enhanced intra-operative ultrasound during surgery for colorectal liver metastases.
BACKGROUND
Contrast-enhanced intra-operative ultrasound (CE-IOUS) for colorectal liver metastases (CLMs) has become a part of clinical practice. Whether it should be selectively or routinely applied remains unclear. The aim of this study was to define criteria for the use of CE-IOUS.


METHODS
One-hundred and twenty-seven patients underwent a hepatectomy for CLMs using IOUS and CE-IOUS. All patients underwent computed tomography (CT) and/or magnetic resonance imaging (MRI) within 2 weeks prior to surgery. The reference was histology, and imaging at 6 months after surgery. Univariate and multivariate analyses were performed. Statistical significance was set at P = 0.05.


RESULTS
Using IOUS an additional 172 lesions in 51 patients were found. CE-IOUS found 14 additional lesions in 6 patients. Seventy-eight CLMs in 38 patients appeared within 6 months after surgery. The sensitivity, specificity, positive- and negative-predictive value were 63%, 98%, 100% and 27% for pre-operative imaging, 87%, 100%, 100% and 52% for IOUS, and 89%, 100%, 100% and 56% for IOUS+CE-IOUS, respectively. CE-IOUS allowed better tumour margin definition in 23 patients (18%), thus assisting resection. Analyses indicated that the presence of multiple (P = 0.014), and isoechoic CLMs (P = 0.049) were independently correlated with new findings at CE-IOUS.


CONCLUSIONS
Compared with IOUS, CE-IOUS improved detection and resection guidance. These additions are significant and demand its use in cases with multiple and isoechoic CLMs.
Department of Hepatobiliary Surgery, University of Milan, Humanitas Research Hospital, Milan, Italy.
Guido
G
Torzilli
Florin
F
Botea
Matteo
M
Donadon
Matteo
M
Cimino
Fabio
F
Procopio
Vittorio
V
Pedicini
Dario
D
Poretti
Marco
M
Montorsi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D006498:Hepatectomy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D059146:Metastasectomy / Q000009:adverse effects / Q000379:methods*; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D018579:Patient Selection; D011237:Predictive Value of Tests; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
D003287:Contrast Media