Percutaneous Endoscopic Gastrostomy Tubes
Percutancous gastrostomy tube placement
There are two basic techniques for percutancous placement of gastrostomy tubes. One technique uses an endoscope, whereas the other involves a "blind," nonendoscopic approach using a gastrostomy tube placement device or applicator. The advantages of percutaneous vs. surgical gastrostomy tube placement are ease and speed of placement, lower cost and less tissue trauma
Percutaneous endoscopic gastrostomy tubes
Percutaneous endoscopic gastrostomy (PEG) tubes are inserted with the aid of general anesthesia. The patient is placed in right lateral recumbency and an area of the left flank extending 4 to 6 inches caudal to the last rib is surgically prepared. Figures 1 to 8 describe tube placement technique in detail. Landmarks for feeding tube placement are usually I to 2 cm caudal to the last rib and one-third the distance from the ventral border of the epaxial musculature to the ventral midline. Commercial 20Fr. Pezzer catheter assembly kits are now available for small animal patients and provide cost-effective, convenient materials for PEG tube placement (Figure 5).
Following insertion, the tube is usually incorporated into a light bandage, with the free end brought to a convenient position for feeding. PEG tubes should be left in place for a minimum of five to seven days. Firm adhesions between the gastric serosa and the peritoneum have been reported to form within 48 to 72 hours of PEG tube placement in healthy dogs but do not reliably form in healthy cats. Adhesion formation may also be variable in undernourished animals. Complications of PEG tube placement include vomiting, peristomal skin infection, cellulitis and pressure necrosis at the tube exit site.
Figure 1. The animal is positioned in right lateral recumbency and an endoscope is introduced. The stomach is insufflated with air so that the gastric wall comes in contact with the body wall and the spleen is displaced caudally.
|Figure 2.. The lighted tip of the endoscope will be seen pressing outward against the abdominal wall. A large-bore needle or over-the-needle intravenous catheter is inserted into the stomach adjacent to the endoscope tip.||Figure 3. Nylon suture is advanced through the needle or catheter until it can be grasped with endoscopic retrieval forceps. The suture material is pulled out through the mouth as the endoscope is withdrawn.|
Figure 4. Commercial 20-Fr. Pezzer catheter assembly kits provide the most convenient materials for PEG tube placement. The catheter guide is already secured to the free end of the feeding tube in commercial kits.
|Figure 5. The lubricated catheter is drawn down the esophagus as the suture exiting the body wall is pulled. A second "safety" suture is placed through the openings in the mushroom-tip feeding tube (insert) and exits the mouth. This safety suture is used to retrieve the feeding tube from the stomach if problems occur during the placement procedure||Figure 6. Resistance wi be encountered when the catheter tip guide contacts the body wall. Steady traction and firm application of counter-pressure to the body wall will allow the guide tip to emerge through the skin (arrow). A small skin incision (2 to 3 mm) at the point of exit may help.|
Figure 7. Gentle traction is used to bring the stomach and abdominal wall into loose contact. A rubber flange is fitted down the tube and a piece of tape attached to prevent tube slippage. The tube is not usually sutured or glued to the skin. The safety suture is removed via the mouth (arrow) after the feeding tube is secured.
|Figure 8. PEG tubes are usually removed by traction. The mushroom tip will usually collapse as it pulls through the abdominal wall. The resulting gastrocutaneous fistula usually heals rapidly.||Figure 9. Commercial gastrostomy tube placement devices in various lengths and diameters can be used for percutaneous nonencloscopic gastrostomy tube placement in dogs and cats.|
The stomach should be empty when the tube is removed. Sedation or anesthesia is not generally required for tube extraction. Tubes are removed by exerting firm traction on the tube, while simultaneously applying counter-pressure around the exit site (Figure 8). An alternative method of removal, suitable for dogs weighing more than 10 kg, is to cut the catheter off flush with the skin, leaving the catheter tip to be passed in the feces. The resulting gastrocutancous fistula usually heals rapidly.
Percutaneous nonendoscopic gastrostomy tubesPercutaneous gastrostomy techniques have been developed to allow convenient, cost-effective placement of feeding tubes without relying on availability of relatively expensive endoscopes. One nonendoscopic technique uses a commercial feeding tube applicator device (Figure 9). The other nonendoscopic technique uses a commercial gastrostomy tube placement device (Figure 10) pressed against the stomach wall. Use of either device allows suture material to be placed through the body wall into the stomach and retrieved through the mouth, and a gastrostomy tube to be inserted as described for PEG tube placement.
Main Subject Index Managing PEG Tubes