Biliary Drainage & Stent
- Percutaneous biliary drainage is plumbing: when bile can't drain the normal way (out through the bowel), we poke a tube into a dilated duct in the liver and give it somewhere to go.
- We usually start with a drain (external or internal-external), then often follow with a stent — plastic for short-term, metal for malignant, lifelong obstruction.
- The two big up-front reasons are decompressing an infected, blocked system (cholangitis — a true emergency) and relieving obstructive jaundice when ERCP failed or isn't possible.
- The headline complications are bleeding (you're tunneling through liver, which is a sponge full of vessels) and sepsis (you're touching infected bile).
- This is the percutaneous backup to ERCP, not its replacement — endoscopy usually goes first.
Bile is the liver's used dishwater. It's made constantly, it carries away waste, and it's supposed to trickle down the bile ducts, through the pancreas's neighborhood, and out into the duodenum to help digest your lunch. When something corks that pipe — a stone, a tumor, a stricture — the bile has nowhere to go. It backs up, the ducts upstream swell like an overfilled garden hose, the patient turns yellow, and if that stagnant bile gets infected, you have a genuine "this person could die tonight" situation.
When the endoscopists can't reach the blockage from below, interventional radiology drains it from above. That's the whole job.
Why someone ends up on the table
The two questions that put a patient here are simple: is the system blocked, and is it infected?
- Acute cholangitis — infected bile behind an obstruction. This is the emergency. Pus under pressure in the biliary tree seeds the bloodstream fast, and antibiotics alone can't fix a plumbing problem. The fix is decompression: open a path and let the pressure out.
- Obstructive jaundice — usually from a tumor at or near the bile duct (cholangiocarcinoma, pancreatic head cancer) or a stricture. Relieving it stops the itching, the jaundice, and the slow poisoning of the liver, and it can make a patient well enough for chemo or surgery.
The first move for most biliary obstruction is ERCP — the endoscope goes down the throat and works upstream through the duodenum. Percutaneous biliary drainage is what we do when ERCP fails, can't reach (e.g., altered anatomy after surgery), or the obstruction is too high in the tree. Think of it as coming at the same clogged pipe from the opposite end.
The technique, in plain plumbing terms
Picture the biliary tree as a real tree turned upside down: tiny twigs deep in the liver merging into branches, then into the trunk (the common bile duct) heading for the gut. We need to get a wire into one of those branches.
First we find a duct. Because the obstruction has backed everything up, the ducts are dilated and easy to see on ultrasound — a happy side effect of the disease making its own road signs. Under ultrasound and fluoroscopy, a thin needle goes through the skin, through the liver, and into a bile duct. We inject contrast to light up the tree (a cholangiogram) and confirm we're in the right place and see exactly where the blockage sits.
Then it's the classic IR sequence: a wire through the needle, the needle swapped for a catheter, and the wire coaxed across the blockage into the bowel. Once we're across, we leave a drain. There are three flavors, and the difference is just where the bile ends up going:
| Type | Where bile drains | When it's used |
|---|---|---|
| External drain | Out to a bag on the skin | Can't cross the blockage (yet), or want pure decompression first |
| Internal-external drain | Both to a bag AND down into the bowel | Crossed the blockage; the workhorse tube, can be capped to drain internally |
| Internal stent | Only down into the bowel, no external tube | Definitive relief once the path is established |
An external-only drain dumps bile into a bag, and that bag isn't just laundry — losing all that bile means losing fluid, electrolytes, and bile salts the gut needs. Internal-external drains are preferred when you can cross the obstruction precisely because the bile can go back down where it belongs.
Drains versus stents
A drain is a tube you can flush, exchange, and pull. It's the temporary scaffold. A stent is the permanent (or semi-permanent) tunnel left behind once you trust the path.
- Plastic stents are cheaper and easy to swap, but narrow and prone to clogging — good for benign or short-term problems.
- Metal stents (self-expanding mesh) open wider and stay open longer, so they're the usual pick for malignant obstruction where the patient won't outlive the stent. The trade-off: they're far harder to remove, so you commit when you place one.
What goes wrong
You are threading hardware through the liver — a dense sponge laced with blood vessels and bile ducts running side by side — so the two headline risks fall out of the anatomy itself.
Bleeding is the one that haunts IR here, because a bile duct and a blood vessel travel together. Nick a vessel on the way in and you can get bleeding into the ducts (hemobilia), the abdomen, or along the tract. Picking a peripheral duct and a careful approach reduces, but never erases, the risk.
Manipulating an infected, obstructed system can shower bacteria into the blood and tip a patient into sepsis on the table. In suspected cholangitis the plan is antibiotics on board first, then decompress — and decompress gently, without over-injecting contrast into a pressurized, pus-filled tree.
Other tariffs of the procedure include leakage of bile into the abdomen, the tube falling out or clogging (drains need flushing and periodic exchanges — a tube is a maintenance relationship, not a one-night stand), and the usual puncture neighbors like pneumothorax if the approach runs high near the lung.
The one thing to keep
Strip away the wires and the jargon and it's a single idea: bile that can't drain the normal way needs a new exit, and IR can build one from the outside. Decompress the infected, pressurized system first to save the patient now; restore a durable path — drain, then stent — to keep them well later. If you also want the gallbladder-specific cousin of this procedure, see percutaneous cholecystostomy; for the upstream "why is this duct blocked" story, the gallstones and biliary disease and cholangitis pages set the scene.