The usual indications for gastrostomy include the need for feeding, decompression, or gastric access. In feeding situations, the gastrointestinal tract must be functional and the need for enteral feeding must be for a prolonged interval. Stamm gastrostomies are most commonly performed at the conclusion of some other major gastrointestinal procedure while the abdomen is open, however the percutaneous endoscopic gastrostomy (PEG) allows the placement of a gastrostomy in adults and children without laparotomy. This technique depends upon the safe passage of an endoscope into the stomach, which can be dilated with air. Inability to pass the endoscope safely and inability to identify the transabdominal lumination of the lighted endoscope tip within the dilated stomach are contraindications to the procedure. Ascites, partially corrected coagulopathy, and intra-abdominal infection are relative contraindications to the PEG method.
The indications for the gastrostomy dictate the extent and type of preoperative preparation. Passage of a nasogastric tube for gastric decompression is usually not needed if the patient has been nothing by mouth (NPO) for several hours. A single dose of intravenous antibiotic may be given within 1 hour prior to the procedure because the peroral passage of the special catheter may contaminate the abdominal wall tract created as the catheter is brought out through the stomach.
A topical anesthesia for the oropharynx is needed for passage of the endoscope, and local anesthesia is used at the abdominal site where the special catheter will be placed. An intravenous needle or catheter is positioned for administration of sedatives.
The patient is usually supine while the topical anesthetic is sprayed into the oropharynx. He or she is allowed to gargle, swallow, or spit into a basin. After satisfactory anesthesia is obtained, the patient is positioned supine on the table with the head slightly elevated.
In adults as well as children, the smallest possible gastroscope is used. After the endoscope is passed safely into the stomach, the skin of the abdomen and lower chest is prepared with antiseptic solutions in the usual manner. Sterile drapes are applied.
During the placement of the gastroscope, any pathology may be evaluated. The stomach is fully inflated with air. This displaces the colon inferiorly and places the anterior gastric wall against the abdominal wall over a large area. A suitable zone is selected and the endoscopist places the lighted gastroscope end firmly upward at this point. This is usually halfway between the costal margin and the umbilicus (figure 1). The room lights are dimmed and the transilluminated site is identified. In very thin patients, the tip of the endoscope may be palpated. The area of transillumination is marked for incision (figure 1). ...