ACCESOS ENTERALES

Indications Gastrostomy Long-term (> 4–6 weeks) gastric feeding required under the following circumstances: Patient is unable to swallow. Oral feeding is precluded. Oral intake alone is inadequate. Long-term gastric decompression. Intolerance to nasogastric or Dobbhoff tube, or both. In cases requiring access to the gastric lumen for < 4–6 weeks, a nasogastric or Dobbhoff tube generally suffices. Percutaneous endoscopic gastrostomy (PEG) is the procedure of choice, when feasible, for gastrostomy placement alone. If the stomach is not accessible percutaneously or if gastrostomy is performed at the time of another upper abdominal operation, an open technique is used. Witzel Jejunostomy Secondary procedure during extensive upper digestive tract surgery (eg, esophagectomy, total gastrectomy) to enable early enteral feeding, particularly when recovery is expected to be long and potentially complicated. Sole procedure in patients in whom oral feeding is precluded and postpyloric feeding is desired (eg, patients with duodenal trauma, gastroparesis, or pancreatitis).

Contraindications Gastrostomy Absolute Absence of stomach (subtotal gastrectomy, transhiatal esophagectomy with gastric pullup). For PEG, esophageal obstruction. (Stamm gastrostomy remains feasible.) For PEG, lack of access to esophagus (eg, trismus, teeth wired shut). (Stamm gastrostomy remains feasible.) Relative Severe gastroesophageal reflux or incompetent lower esophageal sphincter. Anatomy that prevents direct apposition of the stomach with the abdominal wall (eg, interposition of an enlarged liver; severe kyphoscoliosis). For PEG, morbid obesity. (Stamm gastrostomy remains feasible.) Ascites. Irreversible coagulopathy. Witzel Jejunostomy Absolute Distal intestinal obstruction. Small bowel dysmotility. Relative Hostile abdomen (adhesions, malignancy). Inflammatory bowel disease or postradiation enteritis involving the jejunum. Ascites. Irreversible coagulopathy. Significant bowel wall edema. Severe immunodeficiency.

Informed Consent Gastrostomy Expected Benefits Permits gastric feeding or decompression more conveniently and comfortably than by nasogastric tube. Potential Risks Gastric leak. Injury to adjacent organs, including colon, small intestine, and liver. Gastrocutaneous fistula. Bleeding. Infection. Risks inherent to sedation or general anesthesia. Metastatic oropharyngeal cancer rarely occurs at the PEG site (< 1% occurrence), and usually occurs in rapidly progressive disease with other sites of metastasis. Witzel Jejunostomy Expected Benefits Provides a means for enteral feeding that bypasses the stomach and upper digestive system. Potential Risks Damage to surrounding structures, including bowel wall injury. Enteroenteric or enterocutaneous fistula. Bleeding. Infection. Risks inherent to general anesthesia.

Equipment Percutaneous Endoscopic Gastrostomy Upper gastrointestinal endoscope. PEG kit (commercially available). Stamm Gastrostomy 18–22 French Malecot, Pezzer, or equivalent catheter, such as a 20 French Ponsky replacement PEG tube. Witzel Jejunostomy 12–16 French red rubber catheter.

Patient Preparation Percutaneous Endoscopic Gastrostomy Thorough history and physical examination are generally sufficient to rule out the presence of conditions that would preclude or contraindicate the procedure. There must be sufficient space between incisors to pass an endoscope without compromising the airway. In the case of previous abdominal surgery or an otherwise questionable abdominal examination, a limited abdominal CT scan can be obtained to determine whether direct apposition of the stomach and anterior abdominal wall is possible. Nothing by mouth for 4 hours before the procedure. Antibiotic prophylaxis is optional. Stamm Gastrostomy and Witzel Jejunostomy Same as for any major abdominal operation. Both procedures are most easily performed under general anesthesia. Alternate methods of anesthesia such as deep sedation and local anesthesia can be performed in special circumstances.

Patient Positioning Percutaneous Endoscopic Gastrostomy The patient should be supine. The head of the bed may be elevated to 45 degrees as the scope is passed, but the best percutaneous access to the stomach is achieved when the patient is fully supine. Stamm Gastrostomy and Witzel Jejunostomy The patient should be supine.

Procedure Percutaneous Endoscopic Gastrostomy The patient is given intravenous conscious sedation before beginning the procedure. A nurse assistant should monitor the blood pressure, pulse, and oxygenation. The posterior pharynx is anesthetized with a topical agent. A bite block is placed between the incisors. The upper gastrointestinal endoscope is passed through the pharynx and esophagus and into the stomach. The stomach is insufflated with air. The anterior wall of the stomach is localized through the left upper quadrant abdominal wall by gentle digital palpation, transillumination, or both. Gentle pressure of a finger on the abdominal wall should visibly depress the stomach on endoscopic view. The best gastrostomy site is usually left subcostal, near the midclavicular line. It is helpful to mark the skin at the desired puncture site. Figure 10–1A: Following sterile preparation and draping, local anesthetic is injected first intradermally and then into the muscle and peritoneum through which the tube will pass at an angle perpendicular to the skin. A few moments is allowed for the anesthetic to take effect. A scalpel is then used to make an 8–10-mm incision in the skin. Figure 10–1B: A needle/cannula is passed through this abdominal wall incision and into the stomach. Entry into the gastric lumen is observed through the endoscope. A snare passed through the endoscope is looped around the cannula. The needle may be removed or retracted from the cannula. A guidewire is passed through the cannula into the gastric lumen, where it is grasped by the snare. The snare holding the guidewire and the endoscope are pulled out together through the patient's mouth. At the end of this maneuver, the guidewire provides a continuous pathway through the mouth, esophagus, gastric lumen, and abdominal wall (see Figure 10–1C). An alternative method, if a suitable snare is not available, is to pass the guidewire through the accessory channel of the endoscope and directly out through the cannula. Figure 10–1C: The tapered end of the special percutaneous gastrostomy tube is threaded completely over the wire that exits from the patient's mouth. The guidewire is held at the flanged end of the tube as the wire is pulled out through the abdominal wall, bringing the tapered end of the tube down through the esophagus and out through the abdominal wall. Once the tapered tip of the tube emerges through the skin, the tube is grasped and quickly pulled through the abdominal wall until the flanged end is brought into apposition with the internal gastric wall. Counterpressure is held against the anterior abdominal wall during this maneuver to prevent the abdominal wall from being pulled up and away from the stomach. The tube is secured in place by sliding an external crossbar over the tapered end of the tube until it is snug against the abdominal wall. The external portion of the gastrostomy tube is cut to an appropriate length and capped with an adapter. Figure 10–1 Stamm Gastrostomy Figure 10–2: The site at which to bring out the tube is selected and marked approximately 3 cm to the left of the midline and 2–3 cm below the costal margin. Following sterile preparation and draping, a 5–6-cm midline incision is then made at the level of the chosen gastrostomy site. Once the peritoneal cavity is entered, the stomach is identified. The tube should be placed as proximally as possible in the stomach. The greater curvature of the stomach is pulled downward gently with Babcock clamps until resistance is met. A gastrotomy site is chosen on the anterior gastric wall near the greater curvature. Placement is checked to ensure that this site will reach the abdominal wall at the exit site previously chosen. Figure 10–3: An absorbable or nonabsorbable purse-string suture is placed at the site chosen for the gastrotomy and left untied. A gastrotomy is made in the center of the purse-string using electrocautery. Penetration to mucosa is confirmed and the edges of the gastrotomy are held with Allis clamps while the tube is inserted into the stomach through the gastrotomy. The purse-string suture is tied down. A second purse-string suture is placed around the first for further security (not shown). Figure 10–4: A stab wound is then made at the previously marked exit site on the abdominal wall, and a clamp is pushed bluntly through the abdominal wall, entering peritoneum at least 2 cm from the midline fascial incision. The external end of the tube is pulled partway through this opening. Figure 10–5: The free intra-abdominal portion of the tube is used to manipulate the stomach while four sutures are placed to secure the stomach to the abdominal wall. Figure 10–6: After the sutures are placed, the tube is pulled completely through the abdominal wall apposing the stomach to the abdominal wall's underside, and the sutures are tied down. The external portion of the tube is anchored to the skin with an external crossbar, suture, or both. Finally, the original midline incision is closed. Figure 10–2 Figure 10–3 Figure 10–4 Figure 10–5 Figure 10–6 Witzel Jejunostomy If jejunostomy is the sole procedure being performed, a short midline incision is made in the abdomen. Once the peritoneum has been entered, the small bowel is identified and traced to the ligament of Treitz. A loop of jejunum approximately 20 cm from the ligament of Treitz is brought up into the wound. Figure 10–7: A 3-0 absorbable or nonabsorbable purse-string suture is placed in the antimesenteric wall of the jejunum at the planned enterotomy site and left loose. A second purse-string suture may be placed concentrically around the first; this is also left loose. Figure 10–8: The catheter is brought onto the field and placed through an enterotomy made in the center of the purse-string sutures into the bowel lumen. The tube is advanced a distance of 8–10 cm or more and the purse-string sutures are tied down. A Witzel serosal tunnel is created by bringing the bowel wall over the tube for a distance of 4–6 cm proximal to its insertion site using a series of interrupted Lembert seromuscular 3-0 silk sutures. The tube, including its insertion site into the small bowel, is completely invaginated in this way with great care taken not to overly narrow the lumen of the jejunum at the site of tube entry and Witzel tunnel. The external end of the catheter is brought out through a stab wound in the abdominal wall. Figure 10–9: The jejunum is anchored to the peritoneum using interrupted 3-0 silk sutures for a length of 2–3 cm proximal to the serosal tunnel in order to prevent volvulus around the tube. The external portion of the catheter is secured to the skin with nylon suture or other external fixation device. Finally, the original midline incision is closed. Figure 10–7 Figure 10–8 Figure 10–9 Alternative Techniques A jejunostomy tube can also be placed using the needle catheter technique. A 9 French catheter is passed via a needle/cannula through the abdominal wall, through a submucosal tunnel in the jejunal wall, and then into the jejunal lumen. The jejunum is sutured to the anterior abdominal wall to prevent volvulus around the catheter insertion site. Although this technique is simple and can be performed quickly, it has a higher complication rate than standard jejunostomy. The small catheter is more prone to clogging and kinking and is difficult to replace, making it unsuitable for long-term use. There have also been reports of serious infections occurring after needle catheter jejunostomy. If a patient has a gastrostomy and postpyloric feedings are desired, a gastrojejunostomy (G-J) extension tube can be used. The original gastrostomy tube is removed and a G-J tube is inserted. Under endoscopic control, the jejunal extension is threaded through the gastrostomy portion of the G-J tube and placed in the fourth portion of the duodenum.

Postoperative Care Percutaneous Endoscopic Gastrostomy A percutaneous gastrostomy may be used for medication administration immediately and for feeding within 6–12 hours. The patient should be instructed that the retention bar, which is initially snug, may be loosened slightly after 24–48 hours. Stamm Gastrostomy Unlike a PEG, an open gastrostomy tube is connected to gravity drainage for 12–24 hours before being used for feeding. This allows for verification that gastric emptying is taking place. Witzel Jejunostomy The jejunostomy tube can be used immediately following the procedure. Tube feedings should be started slowly, at one-fourth or one-half strength, to avoid osmotically induced ischemic injury.

Potential Complications Gastrostomy Intraperitoneal leakage of gastric contents. External leakage of gastric contents around the tube, especially if the tube is too loose or if the tube has been placed in the antrum rather than the body of the stomach. Gastric outlet obstruction if the tube has been placed distally in the stomach and occludes the pylorus. Puncture of the colon, small intestine, or liver (greater risk with PEG). Cellulitis or subcutaneous abscess at the tube exit site. Accidental dislodgment of the tube. Witzel Jejunostomy Failure to place the tube in the proximal jejunum. Rotation or volvulus of the small bowel around the jejunostomy site. Bowel obstruction due to narrowing and edema at the site of tube entry and Witzel tunnel. Kinking of the tube at the tube insertion site. Intraperitoneal leakage at the jejunostomy site. Intra-abdominal or subcutaneous abscess formation. Enterocutaneous fistula.

Pearls and Tips Percutaneous Endoscopic Gastrostomy The procedure may be done in an endoscopy suite or at the bedside in an ICU. However, if the patient is poorly cooperative (eg, developmentally disabled) or cannot protect his or her airway, the procedure is best done in an operating room with full anesthesia support. It is helpful to have a Dobbhoff tube already in place to follow when passing the endoscope in patients who cannot swallow effectively or in those whose oropharyngeal anatomy is distorted by tumor or prior operation. If the external crossbar is too tight, the risk of infection is increased. If the site is painful or if infection develops around the tube, the crossbar should be loosened to relieve pressure on the skin and to permit drainage. Free air may be seen on a chest film after a PEG is placed. This does not necessarily imply leakage. A contrast study through the tube is the best way to rule out a gastric leak. When there is uncertainty about the patient's anatomy, obtain a contrast study to locate the stomach anatomically and determine suitability for the procedure. A blind puncture should not be done. Stamm Gastrostomy It is technically much easier to place the second purse-string suture in the stomach after the tube has been inserted and the first purse-string suture tied down. Lifting the stomach wall by gently pulling up on the tube facilitates placement of the second purse-string suture. It is technically easier to place the sutures securing the stomach to the abdominal wall before the stomach is pulled up tight against it. Initially pulling the gastrostomy tube only halfway through the exit site facilitates circumferential suture placement. If using a Malecot or similar tube, an external crossbar can be fashioned by cutting a segment of a large red Robinson catheter and trimming a small hole on each side through which to pull the gastrostomy tube. A silastic crossbar is included with the Ponsky tube. A Foley catheter can be used if nothing else is available, but it is not durable and gastric contents tend to leak around the tube. If the stomach cannot be brought to the abdominal wall, a Witzel technique can be used to place the gastrostomy tube, obviating the need for gastropexy (see later discussion). It is always best to bring the tube out through a separate stab wound rather than through the midline incision. Witzel Jejunostomy Jejunostomy tubes are easily pulled out because they do not have an inner flange. If this occurs shortly after tube placement, it can be difficult to reinsert the tube because the Witzel tunnel closes down rapidly. Fluoroscopy may be helpful for attempting reinsertion. If using a red rubber catheter for the jejunostomy tube, cut the tip off of the tube so that exchange over a guidewire is possible if the tube clogs in the early postoperative period. Supplemental free water must be given in addition to tube feedings, particularly if tube feedings are hyperosmolar. Do not start with full-strength tube feedings.

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