Laparoscopic ultrasound for the detection of hepatic metastases during laparoscopic colorectal cancer surgery

PURPOSE: The search for liver metastases before surgery forms an accepted p art of colorectal cancer surgical practice. Intraoperative ultrasound and m anual palpation of liver together form the criterion standard as far as scr eening for metastases is concerned. However, extracorporeal imaging, such a s ultrasound and magnetic resonance imaging, are also widely used. The purp ose of this study was to demonstrate the efficacy of laparoscopic ultrasoun d scan in detection of river metastases during laparoscopic colorectal canc er surgery by comparison with conventional imaging modalities. METHODS: A p rospective, controlled study was undertaken. A total of 76 consecutive pati ents undergoing laparoscopic colorectal resections for malignancy were recr uited. Patients underwent preoperative liver ultrasound scan and intraopera tive blinded laparoscopic ultrasound scan examination performed by a single surgeon. Contrast-enhanced magnetic resonance imaging was performed within 30 days of surgery. RESULTS: Conventional ultrasound scan was negative in all cases. Metastases were identified during simple laparoscopic inspection of the liver in one case. Two cases shown by laparoscopic ultrasound scan to have definite metastases were confirmed by magnetic resonance imaging. I n seven further instances laparoscopic ultrasound scan identified suspiciou s liver masses. In three cases these mere confirmed to be metastases at mag netic resonance imaging; one was confirmed as a cyst, and the remaining thr ee suspicious lesions were confirmed at serial magnetic resonance imaging s cans to be benign and of no significance. CONCLUSION: Laparoscopic ultrasou nd scan with a flexible-tipped probe permits satisfactory hepatic examinati on. It is superior to conventional ultrasound scan and seems to be as effec tive as magnetic resonance imaging, although the latter modality is still r equired to delineate identified lesions.