You review a patient on the ward for abdo pain and pyrexia, and they have some sort of tube with feeds going into their stomach. You need to call the surgeons for a consult for their abdo pain. But what you call it? Do you know the difference between your PEGs and gastrostomies? Do you understand about tube calibres and lengths? In this four-part series, Camille Wu covers everything the general paediatrician needs to know about enteral feeding via gastrostomies….
All the different “types” of gastrostomy refer to how the gastrostomy is formed. This week we will cover the basics of what the gastrostomy formation names mean.
This is the ‘old-fashioned’ way.
A laparotomy is done to identify the stomach, then an incision is made in the left upper quadrant (LUQ) where gastrostomy will be sited. Then the stomach is brought to this incision and the stomach is opened. The device is inserted through the skin into the stomach lumen, and the stomach is sutured to the anterior abdominal wall (so it doesn’t fall away when the device is removed).
Increasingly performed over an open gastrostomy, EXCEPT in tiny neonates or if multiple adhesions preclude laparoscopy.
Laparoscopic gastrostomy formation in 6 easy steps:
- A: Umbilical incision made for a 5mm laparoscope/camera to identify stomach
- B: LUQ incision is made through which the stomach is grasped under vision
- C: Stomach pulled up to skin level
- D: The stomach is opened & sutures are placed to secure the stomach to abdominal wall
- E: The device (tube or button) is now inserted, and checked
- F: Device is accessed and secured
A PEG is the quickest method of forming a gastrostomy, but requires an Endoscopist and a Surgeon.
Only a tube can be placed when PEG is performed (although there may be conversion kits to make the tube shorter).
How to perform PEG insertion:
- Endoscopist inserts gastroscope to visualize gastric lumen
- Surgeon performs percutaneous stab to enter stomach – Endoscopist confirms needle is in gastric lumen
- Surgeon passes wire through needle, for Endoscopist to grasp and pull out through mouth
- Endoscopist ties PEG tube to their end of the wire (oral end)
- Surgeon pulls on their end of the wire (abdominal end), pulling PEG tube down the oesophagus and into stomach. Keep pulling until the tube is now outside the abdomen, and the inner phalange of the PEG tube is snug up against the stomach wall
Once the gastrostomy (fistula track) is matured, and the stomach is well-adherent to the abdominal wall (usually 6-8 weeks), the PEG tube can be changed over to a “button”. Normally we do this under endoscopic guidance, to ensure the button is in the correct place (i.e. in the stomach).
One problem with PEG insertion is that you can’t see what is happening in the peritoneal cavity, so you can’t tell WHERE in the stomach the gastrostomy/hole is being made (e.g. body/antrum). You also can’t tell if there is a bit of colon that is interposing itself between the abdominal wall and stomach (hence the risk of gastro-colo-cutaneous fistula – which won’t be recognised until the initial tube gets changed over, and the new tube is placed into colon, rather than into stomach).
Hence the evolution of lap-assisted PEG insertion, where an extra incision is made in umbilicus, for insertion of laparoscope to directly view what’s happening in peritoneal cavity i.e. to ensure that the needle pierces the stomach in the desired position, and that only stomach is pierced, and that there is no colon “kebab’ed” along the way.