Treating biliary obstruction

Planning your approach:

Review any cross-sectional imaging before starting to assess the site of the causative lesion, the distribution of duct dilation and to check for ascites. It almost always pays for you to have a quick look with the ultrasound before starting. Look for dilated ducts and consider whether the ducts are uniformly dilated or there appears to be a segmental pattern of obstruction. Hilar lesions should have both lobes drained unless one of the lobes is very atrophic. Ultrasound guidance is always recommended, it is essential for left lobe punctures but is equally valuable to direct right-sided punctures. The patient should be prepared according to the planned approach to the right/left lobe or both. Before starting:

• Take a control film of the right upper quadrant to look for calcification.

• Make sure appropriate intravenous antibiotics have been given to cover Gram-positive and Gram-negative bacteria.

Blind right-sided punctures:

This was the preferred technique when PTC was for diagnosis, drainage almost invariably required a second puncture of an opacified duct. A ‘blind’ puncture is traditionally made from the right flank below the 10th rib. The point of puncture is in the mid-axillary line. Place sponge forceps at the proposed site of puncture, then fluoroscope to ensure it is over the liver and below the pleural reflection.

Tip

Unguided puncture works for uniformly dilated ducts, otherwise use ultrasound to direct operations.

Infiltrate with local anaesthetic down as far as the peritoneum but try to avoid puncturing the liver capsule. The intercostal vessels run along the inferior border of the ribs and therefore it is best to puncture just above a rib. Make the initial pass with the needle, aiming just cranial to the hilum of the liver. Angulate it about 20 degrees cranially and 20 degrees ventrally ( Fig. 43.1 ).

The needle is advanced into the liver, the central stylet is removed and the connecting tube attached to the needle. Sometimes, bile will drip or can be aspirated from the needle but bile is viscous stuff and you shouldn't bet your life on this happening. Under fluoroscopy, gently inject full-strength contrast as the needle is withdrawn slowly.

Tip

You know you are injecting at the correct rate when the needle tract outlines as a thin line of contrast. Big splurges in the liver parenchyma indicate over-injection.

Clearly, there are lots of tubular structures in the liver other than the bile ducts. When bile ducts fill, contrast tends to flow slowly towards the hilum; in obstructed ducts, the contrast often swirls as it dilutes. Vascular branches are tubular structures that clear the contrast quickly; portal vein and hepatic artery branches flow towards the periphery of the liver, whereas hepatic vein branches flow cranially towards the right atrium. Remember that the biliary radicles course together with portal vein and hepatic arterial branches in the portal triads, so that if you hit one, you are close to the others.

When you hit a bile duct, slowly inject contrast under continuous fluoroscopy. The dependent ducts tend to fill first, so the right posterior duct outlines before the remaining right ducts or the left. The bile ducts have a complex three-dimensional anatomy and anteroposterior and both oblique views are required to analyse them. Take spot radiographs of any abnormal areas. If you are really here only to achieve drainage, then distend only enough to either confirm you are in a suitable duct or where a suitable duct is for your second puncture. Do not over-distend the bile ducts, as this is a sure-fire recipe for cholangitis.

If this is the exceptional case, and you were only in the biliary system for diagnostic purposes, then it is the end of the procedure; pull the needle out and put a plaster over the puncture site. You can press on it if you like but it will not stop the liver from bleeding.

Ascites:

This increases the risk of bleeding from the liver capsule and makes advancing stiff drainage catheters more difficult as the liver moves away from catheter. If there is extensive ascites, it should be drained before PTC. In the presence of a small amount of fluid, you can proceed if the liver abuts the peritoneum at the proposed puncture site. Many operators would choose to perform an ultrasound-guided left lobe puncture in the presence of small-volume ascites. Make sure that you only make a single puncture of the liver capsule.

You do not hit a bile duct at the first attempt:

Do not be surprised, as this is often the case. Angle the needle 5 degrees caudal and dorsal to the initial pass and try again. Do not pull the needle right out of the liver. Stop before you cross the capsule, as fewer punctures = less risk of bleeding. If the patient is not distressed, make up to five attempts and ask the radiographer to alert your boss that you may require assistance.

Contrast extravasate from the bile duct:

Unfortunately, you have lost position or were in a small peripheral branch. This nearly always requires re-directing your puncture. If there is residual contrast in the biliary system, you can aim for this.

The left ducts do not fill:

The right-sided ducts are dependent and fill preferentially; sometimes the left ducts will only fill if the patient is turned right side up. Be careful not to dislodge the needle as you move the patient.