A number of different companies now produce versatile high-resolution equipment providing excellent image quality. Real-time B-mode ultrasound images are of course essential, but the ability to add colour flow, power flow and spectral Doppler is now standard. This allows visualisation of blood flow in vessels, which at its simplest can be used in the initial orientation of structures. The technology is now such that even flow in the smallest vessels can be visualised with high sensitivity and resolution. Facilities on the most advanced systems include multi-planar image reconstruction and 3D automated volume measurement.

Various probe options are available including the authors’ preferred T-transducer (Fig. 14.2a) and the I-style finger-grip transducer (Fig. 14.2b). These can be configured with linear or convex arrays, with the former providing a rectangular field of view and the best spatial resolution at the tissue depths typically encountered in hepatobiliary and pancreatic surgery. Laparoscopic probes in the past required to be placed within a sterile plastic sheath containing conductive gel which was awkward and yielded poor image quality. Probes can now be sterilised in ethylene oxide, allowing direct organ contact with improved image in quality. A 12-mm port is required for use and port placement is described below. The tip of the probe is flexible in two planes, allowing most required angles to be achieved through one port (Fig. 14.2c).

Remote control units are available for sterile use and image/video storage can be integrated with institution picture archiving and communication systems (PACS). Specialised probes have been designed that include a needle guide and come with specific software to aid accurate placement for radiofrequency/microwave ablation.

The access to the organs of the abdomen afforded by open surgery provides an ideal opportunity for contact ultrasonography. The high-frequency, compact equipment now available can be fully sterilised and placed directly on abdominal viscera to obtain high-resolution real-time images of intra-abdominal structures. This gives the operating surgeon an accurate and flexible tool to assess the anatomy, the nature and the extent of disease, aiding operative decision-making.

Intraoperative ultrasound may be useful in surgery for benign or malignant disease and in both cases the approach is the same. A full visual inspection and manual examination is useful and should be performed initially at laparotomy [5]. Together with the preoperative imaging, this will provide valuable information about the nature and extent of disease. Ultrasonography starts at the hepatoduodenal ligament with examination of the structures of the portal pedicle. Placement of fixed surgical retractors including a specific liver retractor on segment IV may aid access. The use of warm saline around the ligament can help if image quality is poor, but is not always required. It often helps if the operator retracts gently on the duodenum, placing the hepatoduodenal ligament under some tension.

To aid initial orientation, the “Mickey Mouse sign” can be useful (Fig. 14.3). The larger portal vein sitting posteriorly, with the bile duct and hepatic artery in front are reminiscent of the face and ears of the famous cartoon character. “Mickey” can be followed up and down, which acts to keep the probe at right angles to the structures. Care must be taken not to compress structures with the probe. The common bile duct is normally around 8 mm in diameter and can be difficult to visualise when not dilated. It can be differentiated from other portal structures by its hyperechoic wall and absence of flow on Doppler.

Non-malignant obstruction of the biliary tree can result from congenital abnormalities but is more commonly associated with gallstones, benign biliary strictures or a consequence of acute or chronic pancreatitis. In 997 consecutive patients selected for laparoscopic cholecystectomy, operative cholangiography was accomplished in 962 (96 %) [6]. Forty-six patients (4.6 %) had at least one filling defect in the common bile duct, although 12 of these patients had a normal cholangiogram within 48 h (26 % possible false-positive rate) and a further 12 (26 %) had spontaneously passed a stone by 12 weeks. Twenty-two patients (2.2 % of total population) had persistent CBD stones 6 weeks after laparoscopic cholecystectomy.

Figures 14.4 and 14.5 and accompanying videos (Videos 14.1, 14.2 and 14.3, respectively) show typical images obtained with ultrasonography during open surgery. This patient presented with obstructive jaundice and cholangitis on a background of upper abdominal pain. A CT showed dilatation of the extra- and intrahepatic biliary tree with no pancreatic duct dilatation and an obstructing 1.5 cm gallstone in the distal common bile duct. Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy was performed and a biliary stent placed. The bilirubin remained elevated and the cholangitis persisted and a second ERCP was performed, with placement of a second biliary stent. The stone was impacted and could not be removed at ERCP. Drainage was achieved and the symptoms of sepsis settled. Given the size and position of stone, clearance by open exploration was performed.

“Mickey Mouse” is identified and the common bile duct seen to be significantly distended at 1.5 cm (Fig. 14.4a). What initially appears to be the proper hepatic artery is actually a prominent gastroduodenal artery. This is followed up and the origin of the right gastric artery is seen (Fig. 14.4b), just before a large common hepatic artery is visualised (Fig. 14.4c). The cystic duct is long and clearly inserts in a low position (Fig. 14.4b). A lymph node is seen behind the common bile duct which does not look enlarged on ultrasonography and is not suspicious on palpation. Towards the confluence of the left and right hepatic duct, plastic stents are seen within the common hepatic duct, with associated acoustic shadowing (Fig. 14.4d). Some debris can be seen at different levels in the duct.