1154: Laparoscopic ultrasonography for abdominal tumors

Abstract

Accurate preoperative staging of gastrointestinal malignancies is of major importance in the decision for adequate stage-related therapy. There is evidence that laparoscopy in combination with laparoscopic ultrasound (L-LUS) is more accurate in the detection of intraabdominal tumors than conventional preoperative imaging. Staging L-LUS is a minimally invasive technique that reveals local tumor extent and intraabdominal disseminated tumor spread. Therefore, laparoscopic ultrasound is an ideal adjunct to laparoscopy because this technique may compensate for the lack of tactile feedback with laparoscopic instruments. The concept of using ultrasound through a laparoscopic access for liver tumors was first described by Yamakawa et al. in 1958, but it was only since the end of the 1980s that laparoscopic ultrasound probes were introduced in the clinical practice. Currently available data indicate that L-LUS provides information similar to that obtained by intraoperative ultrasound and can identify lesions that are too small to be visible by preoperative imaging techniques. Furthermore, L-LUS also allows performance of US-guided biopsy or interstitial therapies as ethanol injection, cryoablation or radiofrequency thermal ablation in the same session. Laparoscopic radiofrequency represents a safe and effective treatment for patients with hepatocellular carcinoma not amenable to surgical resection, especially when the percutaneous approach to the lesion is deemed very difficult or impossible. Better protection of vital structures and a more accurate staging are major advantages of this approach. In the future, these advantages and the possibility to perform a more aggressive approach (in association with local vascular exclusion) could favor a more extensive use of the laparoscopic radiofrequency. More recently, some series of laparoscopic segmentectomy were reported; the authors showed that laparoscopic resections are feasible and safe in selected patients with left-sided and right-peripheral lesions requiring limited resections. Staging L-LUS can also provide a significant effect in the multimodal approach to a population of patients undergoing regional treatment of hepatic colorectal metastases. Staging L-LUS also acts as a bridge to a potential laparoscopic approach of both primary colon tumor and liver metastases. Patients with hilar cholangiocarcinoma and gallbladder cancer frequently have unresectable disease that is not apparent on preoperative imaging studies. L-LUS can correctly identify unresectable disease and prevents unnecessary laparotomy in about one third of patients. Color-coded Doppler imaging can be very valuable for the assessment of resectability in patients with pancreatic cancer. Current data confirm that laparoscopic ultrasound is capable of enhancing the accuracy of staging laparoscopy. Compared to standard laparoscopy, a combination of both techniques markedly increases the sensitivity of staging laparoscopy in the determination of unresectable disease. This is of major importance in the assessment of occult liver metastases and lymph node involvement. Laparoscopic ultrasonography improves the diagnostic accuracy compared to conventional imaging techniques and should be considered as integral part of staging laparoscopy. It may help in choosing the most suitable treatment for the patient. However, a steep learning curve for L-LUS has been reported, and a training workshop experience with LUS will be needed to improve both accuracy rates and LUS technique.