['Laparoscopy may identify occult metastatic disease and prevent unnecessary laparotomy in some patients with potentially resectable colorectal liver metastases but is unnecessary in the majority of individuals who undergo resection. The objectives of the current study were to assess the impact of laparoscopy after extensive preoperative imaging and to determine whether a preoperative clinical risk score can identify those patients most likely to benefit from the procedure.', 'Between December 1997 and July 1999, 103 consecutive patients with potentially resectable colorectal liver metastases underwent laparoscopy prior to planned laparotomy and partial hepatectomy. Surgical findings, length of hospital stay, and hospital charges were analyzed. Patients were assigned a clinical risk score (CRS) based on five factors related to the primary tumor and the hepatic disease. The likelihood of finding occult unresectable disease and the yield of laparoscopy were analyzed with respect to the CRS.', 'Seventy-seven patients (75%) underwent resection. Laparoscopy identified 14 of 26 patients with unresectable disease, 10 of whom were spared an unnecessary laparotomy. In patients who underwent biopsy only, the laparoscopic identification of unresectable disease shortened the hospital stay (1.2 +/- 0.6 days vs. 5.8 +/- 2.3 days; p = 0.0001) and reduced the total hospital charges by 55% (P = 0.0001). The CRS predicted the likelihood of occult unresectable disease, which was 12% in those with a score < or = 2 but increased to 42% in those with a score > 2 (P = 0.001). If laparoscopy were used only in high risk patients (CRS > 2), 57 laparoscopies would have been avoided and the net savings doubled.'] Does a clinical scoring system predict the yield of diagnostic laparoscopy in patients with potentially resectable hepatic colorectal metastases?