THE EFFICACY OF DIAGNOSTIC LAPAROSCOPIC ULTRASOUND

Precise staging of malignant disease is required to define the optimum therapeutic strategy. In spite of technical advances, the sensitivity of conventional imaging techniques is usually limited to defining les ions of at least 1 cm in size. Laparoscopy is a sensitive technique th at is very valuable for visual inspection of the abdominal cavity and the identification of small surface lesions. However, non-superficial lesions may escape detection due to the lack of tactile sensitivity. A s an adjunct to laparoscopy, this study, utilizing a young swine model , has analyzed the detectability of intra-abdominal lymph nodes by lap aroscopic ultrasound (LU). Lymph nodes in and around the hepatoduodena l ligament, examined and measured by LU, were resected by subsequent o pen laparotomy in eight young, mixed-breed swine. The numbers and size s of lymph nodes detected by LU and resected at laparotomy were compar ed and analyzed statistically. Forty-six lymph nodes were resected by laparotomy, while LU failed to detect 3 small nodes (sensitivity, 43/4 6 = 93.5%). The sizes of lymph nodes in the LU group correlated strong ly with the sizes actually measured in the laparotomy group (r = 0.936 , P < 0.001). Twenty-six small lymph nodes, which conventional extraco rporeal imaging might have failed to diagnose, were detected accuratel y by LU (r = 0.877, P < 0.001). This new technology may not only be ef fective for staging intra-abdominal malignant disease, but adds the be nefit of obtaining tissue samples under direct vision using minimally invasive techniques.