Color Doppler sonography in liver surgery. Status of perioperative monitoring

Abstract

Resection of liver tumours is not always successful despite detailed diagnostic work-up preoperatively. In our study we compared the predictive value of colour Doppler imaging of the liver with other radiological examinations for tumour staging, surgical decision making and postoperative complications. From 1/95 to 6/1997 we investigated 76 patients with liver tumours; 60 patients with liver metastases, 13 with primary liver carcinomas and 3 with benign lesions. Resectability was defined in colour Doppler imaging by tumour localisation, distance of the tumour to the central vessels and blood flow in the portal vein. CT-scan in all patients and angiography in patients with central tumour localisation was performed. The preoperative results were compared to intraoperative ultrasound and surgical examination. 108 out of 118 intrahepatic lesions were found preoperatively using high-resolution ultrasound. Ultrasound and CT-scan achieve comparable results in delineating pathologic changes in the liver. Considering only the liver findings and local resectability in 76 patients, the sensitivity achieved for B-mode-ultrasound was 77.6% (59/76); for CT-scan 78.9% (61/76) and for colour Doppler imaging 86.4% (66/76). 31 out of 76 laparotomies were terminated after exploration. Resectability was correctly predicted by ultrasound in 55 (72.4%) and by CT-scan in 57 (73.7%) patients. Colour Doppler imaging improved the ultrasound results in up to 62 (81.6%) patients. Unsuspected not resectable tumour growth was found in 9 patients with local/regional recurrences, in 4 patients with peritoneal spread and in one patient with multiple bilateral liver metastases. Using high-resolution ultrasound systems the preoperative detection of lesions in the liver achieves the results of CT-scan. Little isoechogenic lesions, peritoneal spread and locoregional recurrences can be missed by ultrasound examination. Colour Doppler imaging shows compared with B-mode and CT-scan a higher sensitivity for the detection of the infiltration of hilar structures and can take place of more invasive methods in preoperative liver investigations. Considering functional and morphological aspects colour Doppler imaging makes an essential contribution to the planning of liver surgery. Using lung passing contrast media the determination of tumour vascularisation and perioperative quantification of liver perfusion is possible. The use of the intraoperative ultrasound is justified to determine resection limits, detection of smallest non-palpable lesions and to control perfusion after vascular reconstruction. In experienced hands colour Doppler imaging gives valuable preoperative information with excellent cost-benefit ratio.