Because IOUS always follows the preoperative imaging modalities in the diagnostic workup, its higher sensitivity should be expected and surgeons should take advantage of that. The extensive analysis from Zhang and colleagues on a large series of patients with HCC confirms that IOUS is essential for reoperation and, we may say, makes them possible. These results are encouraging and should be considered in a scientific community that too often neglects the relevance of IOUS, which is more evident in liver surgery. Indeed, detecting new lesions effects the surgical strategy, resulting in better surgical treatments and allowing for a wider range of operations. Furthermore, the potential of IOUS and its effects in liver surgery are far from being completely established. Indeed, IOUS still has a high sensitivity but a low specificity in exploring the cirrhotic liver, and the risk of overestimating or underestimating the real tumor dissemination is probably not negligible. Zhang and colleagues do not mention any false-positive results and surprisingly had the same rate of new tumors in patients with and without cirrhosis, although in the cirrhotic liver, IOUS makes visible many nodules that would be difficult to define as regenerative, dysplastic, or neoplastic. Certainly, the investigators' leading expertise in this field accounts for the high specificity; however, some false-negative lesions may exist, and as the investigators themselves admitted, their recognition could have raised the rate of operations modified by IOUS findings. Contrast-enhanced IOUS may aid in this sense, helping to differentiate the borderline lesions. This may increase the number of removed nodules, exposing the patients to the risk of overtreatment but probably resulting in more radical operations. This is a future scenario that may enhance the value of IOUS, as was well shown in this valuable article.
Torzilli G. Detection of New Tumors by Intraoperative Ultrasonography During Repeated Hepatic Resections for Hepatocellular Carcinoma—Invited Critique. Arch Surg. 2007;142(12):1176. doi:10.1001/archsurg.142.12.1176