Focused abdominal ultrasound in preoperative liver surgery staging: a prospective study

Because of its safety, relative low cost and widespread availability, conventional ultrasound (US) is the modality of choice for initial evaluation of the liver. Following US, in patients eligible for surgery, further computed tomography and/or magnetic resonance imaging is usually recommended for surgical planning. There are no recent published series focusing on conventional abdominal US exclusively employed for the evaluation of liver nodules before surgery. The objective of this study is to evaluate the efficacy of focused conventional preoperative US in detecting liver lesions, and the impact of US findings on surgical management.

Sixty-seven noncirrhotic patients underwent surgical resection, after being previously submitted to focused liver US evaluation. US results were compared with intraoperative US (IOUS) and histology (gold standard). The IOUS was performed by the same radiologist who performed the preoperative US. Patient-by-patient and lesion-by-lesion analyses were performed.

A total of 241 lesions were depicted in 67 patients. The mean number of lesions detected per patient by US and IOUS was 2.37 and 3.37, respectively (P = 0.001). In 52.2% of patients, US and IOUS depicted the same number of liver lesions. Surgery with curative intent was conducted in 61 (91.0%) patients. Histological evaluation was obtained in 196 lesions; 155 were considered malignant. The overall lesions detection rate by US was 65.6%. For lesions <15 mm and lesions ≥15 mm, US showed a sensitivity rate of 55.3% and 75.5%, respectively.

The relatively high sensitivity rates achieved by US focused on liver evaluation, with the aim of lowering costs but not efficiency, places the method in focus again for use in the routine preoperative staging of candidates for liver resection. We suggest for preoperative evaluation that US could be associated with one section imaging method (computed tomography or magnetic resonance imaging) as routine.