Percutaneous endoscopic gastrostomy (PEG) is a gastrostomy procedure that involves gastroscopically mediated placement of a gastrostomy tube for gastrointestinal nutrition or gastrointestinal decompression without surgical intervention or general anesthesia. This technique can provide the nutrition required by the body to sustain life, and for patients with combined obstruction, palliative gastrointestinal decompression can be performed to reduce the irritation and reflux of digestive fluid to the stomach and intestines, reduce pulmonary infections, and improve the quality of life of patients (including patients with advanced tumors).
With the promotion of PEG technology in clinical application in recent years, its indications and methods have made great progress, bringing great benefits to patients with different systemic diseases, and with the improvement of technology, many contraindications in the early stage have also seen different breakthroughs, bringing gospel to more patients. Xiao Mei, Department of Gastroenterology, Anhui Provincial Hospital
I. Indications for PEG
The original PEG technology was first introduced by Gauderer and Ponsky in 1980, mainly designed to provide a long-term enteral nutrition route for patients with normal gastrointestinal function but unable to feed orally, with the aim of replacing surgical gastrostomy. With the promotion of clinical applications, PEG technology can provide a good route for in-hospital and home nutritional support patients, and it is also widely used in nutritional support for pediatric diseases.
Currently, the American Gastrointestinal Association has adopted PEG as the preferred method for patients who cannot eat by mouth but need long-term nutritional supply, clearly stating that: if a patient has normal gastrointestinal function and the expected duration of enteral nutritional support does not exceed 30 d, a nasogastric tube or a nasoenteric tube can be placed for nutritional support; if the expected duration of enteral nutrition is >30 d, a gastrostomy should be considered to improve various causes of malnutrition caused by oral feeding malnutrition due to difficulties in feeding through the mouth and as a therapy to provide additional nutrition and bile replacement.
The PEG technique is also indicated for gastrointestinal decompression of chronic intestinal obstruction secondary to benign or malignant disease. More than 200,000 PEG cases are performed each year in the United States, and this technique is currently performed in several hospitals in China. The indications are divided into the following areas according to their different purposes.
1.Solely for enteral nutrition.
① Central nervous system diseases leading to swallowing disorders;
②Patients with oral cavity, head and neck cancer and esophageal cancer resulting in swallowing disorder;
③ normal swallowing function but insufficient intake, such as burns, acquired immunodeficiency syndrome (AIDS), anorexia, after bone marrow transplantation, patients with severe cranio-cerebral trauma, severe pancreatitis;
④Patients with chronic diseases such as cystic fibrosis, congenital heart disease;
⑤ Treatment of gastric torsion;
⑥Patients with severe maxillofacial trauma.
2. Purely for gastrointestinal decompression: These patients may have severe neurological swallowing disorders or developmental disorders, traumatic or neoplastic obstruction of the oropharynx, or those critically ill patients who require prolonged tracheal intubation, patients who require continuous gastrointestinal decompression. This includes gastroparesis from various causes, pyloric obstruction, intestinal obstruction due to malignancy [7] or impaired gastric emptying, inoperable intestinal obstruction for gastrointestinal decompression.
3.Application in non-nutritional aspects :
①In external drainage bile retrieval for children taking medication and biliary fistula patients;
②Placement of multiple PEGs simultaneously as a gastric fixation method in patients with esophageal hiatal hernia and gastric torsion.
II. Contraindications of PEG
At the early stage of PEG, patients with coagulation disorders, peritonitis, peritoneal dialysis, gastric wall varices, absence of stomach and any inability to perform gastroscopy were regarded as absolute contraindications to PEG. With the progress of clinical treatment and examination techniques, many contraindications can now be treated actively and given the opportunity to undergo PEG surgery.
Patients who cannot see the transillumination point from the abdominal wall during PEG (usually because of obesity, the presence of other structures between the stomach and the abdominal wall), who have a history of left upper abdominal surgery or who have ascites were considered absolute contraindications to PEG in the early stages because of the great risk of intraoperative and postoperative complications. In recent years, PEG can be safely performed in obese patients by incising the skin and subcutaneous tissue under local anesthesia and placing successful sutures afterwards.
Transabdominal ultrasound, CT [8] and ultrasound gastroscopy help to clarify the absence of other tissue structures between the abdominal wall and the stomach and also allow puncture operations under their guidance, which can greatly increase the safety and accuracy during PEG placement. In patients with mild to moderate ascites, the amount of ascites can now be reduced by active preoperative preparation such as laparotomy to release ascites and diuresis, and the gastric wall can be tightened against the abdominal wall to perform PEG surgery [9]. Some patients, including those after left upper abdominal surgery, can also be punctured using the “safe access method” proposed by Foutch.
If safe access can be established at the time of puncture, there is no contraindication in patients after abdominal surgery. This method involves observing the acupressure marks on the gastric wall through the gastroscope while applying finger pressure to the abdominal wall puncture site, with a clear acupressure bulge being the best puncture site. The puncture site should then be reselected.
The safe access approach can also be an alternative to the abdominal wall fluoroscopy point, especially in patients with a thin abdominal wall, and is safer to perform.
In patients with varicose veins in the gastric wall, preoperative gastroscopy can be performed to understand the extent of the presence of varicose veins, and the puncture site should be selected to avoid the varicose veins. However, since patients with varicose veins in the gastric wall are often combined with cirrhosis, esophageal varices and coagulation disorders, the safety and benefit of the patient should be evaluated before performing PEG.
In the early days, total gastrectomy was also considered a contraindication to fistula, but with the advancement of technology, it is now possible to choose the fistula site in the small intestine, which is improved from percutaneous gastrostomy to percutaneous duodenal or jejunostomy, so patients without stomach are no longer a contraindication to PEG.
Esophageal stricture is also not a contraindication to PEG at present, and PEG in these patients can be performed after gastroscopic dilatation or esophageal trocar/stenting [9] or under the guidance of ultra-fine gastroscopy [10,11].
III. Progress and comparison of PEG methods
The initial PEG was the pull-out method proposed by Ponsky and Gauderer, followed by the push-in method proposed by Sacks-vine, and since both methods required two insertions of the endoscope, the insertion (Introducer) method, which requires only one insertion of the gastroscope, was later proposed by Russell. The most clinically used techniques are the drag-out method and the insertion method.
1.Pull out technique.
After the patient takes oral lidocaine syrup or intravenous sedation, the patient is placed in a supine position and the head is elevated by 10-15 degrees, and the patient’s head can be placed on the left side by an assistant to reduce misaspiration.
The gastroscope is inserted and the gastroduodenum is routinely examined for abnormalities. The anterior wall of the gastric body is selected, and the stomach is fully inflated by full gas injection, which can induce the left lobe of the liver to move up and the transverse colon to move down and reduce the intraventricular brightness, and the transillumination point of the gastroscope can be seen from the abdominal wall, indicating that the tissue between the stomach and the abdominal wall has been pushed apart and the stomach wall is in direct contact with the abdominal wall. A biopsy forceps is delivered from the gastroscope to assist in fixing the puncture needle so as not to displace it. After local infiltration anesthesia, an incision of approximately 0.5-1 cm is made in the puncture skin and the sheathed puncture needle is inserted up to the gastric lumen.
A long wire is placed from the trocar into the gastric lumen, and when the wire enters the stomach, it is clamped with a biopsy forceps under the gastroscope and then led out of the mouth as the gastroscope is withdrawn. The end wire of the PEG tube is fastened to the wire outside the oral cavity, and the wire is tightened from the puncture site of the abdominal wall to lead the PEG tube from the esophagus to the stomach and dragged out of the body from the puncture site.
At this point, the gastroscope is inserted again, and the position of the PEG tube head is checked, noting whether there is excessive tension on the gasket inside the catheter head. When the examination is completed, the gastroscope is withdrawn and the PEG tube is fixed by attaching a card to the root of the PEG tube outside the abdominal wall, thus keeping the stomach wall and abdominal wall in close contact.
2.Introducer method.
Preoperative preparation, disinfection and determination of the gastrostomy puncture site are the same as the pull method. Before the puncture needle is used for abdominal wall-gastric wall puncture, the gastric wall and abdominal wall are fixed with surgical sutures 1-2 cm above and below the puncture site of the gastrostomy, then the sheathed puncture needle is used to puncture, and the puncture needle is withdrawn after reaching the gastric cavity, the fistula tube is inserted from the trocar, water is injected into the balloon of the fistula tube, the sheath is peeled off and removed, and under endoscopic surveillance Under endoscopic surveillance, the fistula balloon was made sure to be in close contact with the gastric wall, and the abdominal wall was disinfected and the gastrostomy catheter was fixed. The sutures securing the gastric wall are removed one week after the procedure.
Since the Pull method was proposed, there are few methodological changes, no sutures are required throughout the procedure, less trauma, higher patient comfort, and simple postoperative care, so the drag-out method is still the predominant and most commonly used method of tube placement in current clinical applications. However, in recent years, with the promotion of the Introducer method in clinical applications, its advantages have gradually emerged, and the two are now compared as follows.
(1) Pull method requires two gastroscopic insertions, while Introducer method requires only one gastroscopic insertion, which avoids the possibility of local bleeding, laryngeal edema, asphyxia, tumor implantation and metastasis that may be caused by repeated endoscopic insertion, and reduces the incidence of fistula infection, especially for patients with head and neck tumors, pharyngeal or upper esophageal stenosis who may benefit more.
(2) The Introducer method of gastrostomy requires two sutures of the stomach and abdominal wall, and although a second gastroscopic insertion is not required, the actual operative time required for fistula is roughly comparable to that of the Pull method.
(3) The Introducer method does not require reinsertion of the endoscope when changing the catheter, so it has a greater advantage in clinical application and facilitates early detection of possible displacement of the gastrostomy tube.
(4) The Introducer method requires weekly water changes for the balloon of the fistula fixed in the gastric lumen, which is a greater amount of care for the family and is not as easy to perform as the Pull method.
The PEG technique provides a safe, effective, non-surgical way to establish long-term enteral nutrition access, and has the advantages of simplicity of operation, fewer complications, less invasiveness, easy tolerance in critically ill patients, simple extubation, and rapid postoperative recovery compared with surgical fistula. Compared with the commonly used nasogastric tube, it can reduce the occurrence of gastroesophageal reflux, esophagitis and aspiration pneumonia, and avoid the irritation of the nasopharynx caused by the thick diameter gastric tube, as well as the erosion and discomfort caused by the long-term pressure and abrasion of the nasogastric tube.
Those with mild disease (such as patients with esophageal fistula) can take the tube out to participate in social activities without affecting their dignity, and those with severe disease can easily care for and facilitate the administration of medication. With the clinical promotion and improvement of the technology, PEG has benefited more and more patients, greatly improving their quality of life, prolonging their life expectancy and significantly improving their prognosis.