← Medactic Prototype

Gallstone Playground

Who’s angry tells you where the stone is.

Drag one into a duct, feed the patient, and watch which organs turn on you.

This is a cartoon. Time runs fast and the numbers aren’t patient numbers. It’s for education and simulation only. It isn’t a medical device, so don’t use it for decisions about real patients.

LIVER · RIGHT LEFT LOBE Gallbladder Pancreas Stomach Duodenum CBD CHD cystic duct ampulla pancreatic duct
Fasting

Stones

8 mm · pea

Drag the stone onto the picture, or

Who gets angry?

Drag any stone to move it, or drop it off the organs to throw it away.

Place or move stones without dragging

Procedures

ERCP or a drain buys time. Taking the gallbladder out fixes it, and this toy doesn’t do surgery.

The patient

Who’s angry

Bedside and labs (direction only)

What happened
    Duct pressures

    Model units. About 10–15 at rest.

    How the model works
    • Bile flow. Each liver lobe makes bile into its duct. Secretion falls as the pressure behind it rises, and stops near 32. The right and left hepatic ducts, common hepatic duct, common bile duct, ampulla and pancreatic duct are modelled as compliant compartments joined by resistances.
    • Fasting and meals. Fasting, the sphincter of Oddi holds the ducts at about 12, so bile backs up the cystic duct into the gallbladder, which stores it and absorbs water. A meal lands in the stomach and turns to chyme. Chyme reaching the duodenum releases CCK for a little while, so the gallbladder squeezes and the sphincter relaxes.
    • Stones. A stone at least 90% of a duct’s width plugs it. Smaller ones narrow it and get carried along by the flow until they reach a duct too narrow to pass, or drop into the duodenum. In the gallbladder, a squeeze pushes stones toward the neck. Stones up to 5 mm can squeeze out through the cystic duct and pass a closed papilla, and most slip through without trouble. Here about one in three sets off pancreatitis, whatever its size. That share was picked for teaching and isn’t a real rate. The Small stone preset always causes it. A bigger stone sticks at the neck and blocks it. The first two times it falls back by itself (biliary colic), and after that it stays until a drain has let the gallbladder settle.
    • Angry organs. Each organ’s inflammation climbs within seconds of a blockage and settles once it clears, far faster than in a real patient. The gallbladder reacts to a blocked cystic duct, each liver lobe to its own ducts, and the pancreas to a blocked duct or a stone that just passed. An angry pancreas recovers slowly, and neither a drain nor ERCP speeds that up. An inflamed gallbladder secretes fluid, squeezes less and its wall thickens, so it distends further. Infection in the bile builds if high pressure persists, faster the more of the tree is obstructed. Cholangitis needs antibiotics and the duct drained soon. Here a stuck gallbladder stone stays until drained. Real ones often settle on antibiotics, and the gallbladder still comes out.
    • Labs. Here bilirubin rises when both lobes are obstructed and ALP rises with either. Real patients are less tidy. AST and ALT often spike first and aren’t modelled. After a stone passes, ALP and bilirubin rise briefly and fall. Falling numbers suggest the stone has gone. If they keep climbing it’s probably still there, and that’s when to think about ERCP. The labs only show direction.
    • ERCP. The model holds still while a duodenoscope passes through the stomach to the papilla. If there’s a stone to treat, it cuts the sphincter and pulls out stones up to 15 mm from the common hepatic duct, common bile duct and ampulla. A bigger stone stays, with a plastic stent past it. Stents clog, so that only buys time. With nothing to treat there’s no cut, since MRCP and EUS do the looking. Real ERCP can cause post-ERCP pancreatitis, bleeding, perforation and infection. The model leaves those out, along with lithotripsy and reaching cystic and hepatic duct stones.
    • Drains. A cholecystostomy drains the gallbladder and is for a patient too sick for surgery. Here it also drains the ducts if the cystic duct is open, which you can’t rely on in a real patient. A PTBD drains the lobe it sits in, plus anything connected to it below. ERCP is the usual first choice for duct stones. Neither drain treats the pancreas or removes a stone.
    • Surgery. Once gallstones have caused trouble, cholecystectomy is the definitive treatment, though this toy doesn’t do it. A stone left in a duct comes out first. Silent gallbladder stones usually stay put and need no operation.
    • Also left out: cholecystectomy, bile duct exploration, procedure and surgical complications, imaging, antibiotics, Mirizzi syndrome, gallstone ileus, sepsis physiology, stone formation, AST and ALT, and real lab values.