Intraoperative ultrasound with contrast medium in resective pancreatic surgery: a pilot study

Background. The introduction of contrast-enhanced ultrasound has been a major innovation in liver and pancreatic imaging. Previous studies have validated its intraoperative use during liver surgery, while there is a lack of data regarding its use during pancreatic surgery. The purpose of the present study was to prospectively evaluate the possible role of contrast-enhanced intraoperative ultrasound (CEIOUS) during resective pancreatic surgery for primary lesion characterization and intraoperative staging. Materials and Methods. Thirty-four patients (70% males, mean age 67.9 years) were selected for pancreatic surgery between October 2006 and July 2009. All patients underwent intraoperative ultrasound with intravenous injection of 4.8 mL sulfur-hexafluoride microbubbles. Location of the primary tumor, relation to the main vessels, contrast medium uptake modalities, presence of liver metastases, and multifocal pancreatic involvement were evaluated. The majority of operations were pancreatoduodenectomies (70.6%) performed for pancreatic ductal adenocarcinoma (64.7%). Results. Additional lesions were detected by ultrasound in six patients (17.6%: liver metastases in four patients, a hemangioma in one patient, and a further pancreatic lesion in one patient). In five of these patients (5/34, 14.7%) surgical management was modified by these findings. All these new findings were diagnosed before injection of contrast medium, except for a metastasis from a neuroendocrine tumor; the characterization of the hemangioma was possible only after contrast injection. Intraoperative findings regarding location of primary tumor, relation to the main vessels, and lesion characterization did not differ from those obtained with preoperative imaging. Conclusions. In our experience intraoperative ultrasound is a valid technique for intraoperative staging prior to pancreatic resection; it is unclear whether, in pancreatic surgery, the addition of contrast enhancement adds any benefit to traditional intraoperative ultrasound.