Gastrointestinal Tract Intervention

Indications

Percutaneous gastrostomy is predominantly performed in patients who need prolonged nutritional support, such as patients with neurologic disease (degenerative central nervous system disease, cerebral vascular accidents); head, neck, and esophageal carcinoma; swallowing disorders; and esophageal strictures. Chronic conditions such as cystic fibrosis and congenital heart disease may also require a percutaneous gastrostomy. Occasionally, a percutaneous gastrostomy or gastrojejunostomy may be placed for bowel decompression. Indications include malignant small bowel obstruction or patients with prolonged ileus following major abdominal operations.

Contraindications

Box 19-1 lists absolute and relative contraindications. Absolute contraindications include colonic interposition, total gastrectomy or severe uncorrectable coagulopathy, and extensive gastric varices. In patients with relative contraindications, the procedure may be technically more demanding and require more careful planning but is usually possible.

Technique

Patient Preparation ( Box 19-2 )

Informed consent is obtained before the procedure, usually from a relative or from the patient, if possible. The referring team should be asked to place an intravenous cannula for sedoanalgesia and to fast the patient from midnight of the evening before the procedure. The referring team is also asked to pass a nasogastric tube on the evening before the procedure and administer 300 mL of an oral barium suspension. The barium serves to delineate the relationship of the transverse colon to the stomach on the day of the procedure ( Fig. 19-1 ). When commencing placement of gastrostomy tubes, it is reasonable to give barium beforehand. However, with experience, the barium can be omitted because the colon can be adequately visualized on fluoroscopy without barium labeling. Additionally, when the stomach is distended, it tends to push the transverse colon inferiorly and out of the way. If, however, you are not happy that the colon is visible, air can be insufflated via a rectal tube to demonstrate the colon. Alternatively, if lateral fluoroscopy is available the stomach is distended and a forceps is placed at the skin entry site and the location of the skin entry site vis-à-vis the stomach is ascertained. Usually the stomach is directly underneath the anterior abdominal wall with no intervening bowel loops. When the position of the colon is ascertained, the stomach is distended with air via the nasogastric tube.

Box 19-2

Pregastrostomy Requirements

• Informed consent (usually from a relative)

• Nasogastric tube placement

• 300 mL oral barium the evening before the procedure (optional)

• Intravenous access

Occasionally, in patients with esophageal strictures it may not be possible for the referring team to place a nasogastric tube. In this situation, in the author’s unit, the nasogastric tube is placed under direct fluoroscopic visualization at the time of the percutaneous gastrostomy. It is usually possible to place a nasogastric tube even through tight strictures by first using a 5-French angiographic catheter and a hydrophilic wire. Once the stricture is crossed, the hydrophilic wire can be exchanged for a superstiff wire and a nasogastric tube placed in the stomach.

In the author’s unit, a paralytic agent such as glucagon or n-hyoscine butyl bromide is routinely used to induce gastric paralysis. Antibiotic prophylaxis is not routinely given unless a percutaneous endoscopic gastrostomy (PEG) tube will be placed through the mouth under fluoroscopic guidance. Some authors mark the position of the left lobe of the liver using ultrasound. This is not done in the author’s unit, and there have been no hepatic complications in over more than 500 procedures. Once the stomach is fully distended, the entry site is usually well below the left lobe of the liver. In general, the puncture site should be lateral to the rectus sheath to avoid the superior epigastric artery. If orientation and size of the stomach prevents use of a puncture site lateral to the rectus sheath, then a midline puncture is chosen. A combination of midazolam and fentanyl are used in small amounts for sedoanalgesia.

Gastropexy

The author’s unit performs a gastropexy routinely in all patients. Advantages and disadvantages are discussed later. Gastropexy fixes the anterior wall of the stomach to the anterior abdominal wall and prevents guidewire buckling into the peritoneal cavity and early or late intraperitoneal leakage. Gastropexy is performed using T-fasteners (Kimberly Clark, Draper, Utah, or Balt, Montmorency, France) ( Fig. 19-2 ). With the stomach maximally inflated, the puncture site into the stomach is chosen midway between the superior and inferior margins of the inflated stomach just proximal to the incisura. The puncture site is marked on the skin and subcutaneous injections of local anesthesia are given at the puncture site and at the four corners of a 2.5-cm square around the puncture site. A slotted 18-gauge needle is used to insert four T-fasteners at the corner of this square. The T-fasteners consist of a metal T-bar attached to a nylon suture, which is attached to a cotton wool pledget. The nylon suture runs through the cotton wool pledget, and between the cotton wool pledget and the distal end of the suture there are two small metal cylinders that are freely mobile on the suture (see Fig. 19-2 ).

The T-fasteners are loaded on the slotted 18-gauge needle. The 18-gauge needle is attached to a partially saline-filled syringe and the stomach is punctured at the four corners of the 2.5-cm square. When air is aspirated, the tip of the slotted 18-gauge needle lies in the stomach. The syringe is removed and the stylet is used to push the T-fastener out of the needle and into the stomach. The stylet and needle are removed and gentle tension on the external nylon suture opposes the stomach wall to the anterior abdominal wall ( Fig. 19-3 ). The stomach is fixed in position by crimping the metal cylinders around the suture using a sterile forceps. When all four T-fasteners are in situ, the gastrostomy tube is placed ( Fig. 19-4 ).

Gastrostomy Tube Placement ( Box 19-3 )

The proposed site of entry for the gastrostomy tube (in the center of the T-fastener square) is anesthetized, and a 3- to 4-mm transverse incision is made and dissected with a blunt forceps. The slotted needle that was used for the gastropexy is used to puncture the stomach, and a 0.035-inch superstiff guidewire inserted so that it coils in the stomach lumen. The author tends to angle the puncture site toward the pyloric canal or antrum, so that the angle of the track will facilitate the conversion from gastrostomy to percutaneous gastrojejunostomy if it becomes necessary ( Fig. 19-5 ). It is important to keep the stomach inflated during gastropexy and gastrostomy tube placement. Complications are more likely to be encountered if the stomach is not maximally inflated at all times. Successive fascial dilators can be used to dilate the percutaneous track. The track is dilated to a size that is 1- to 2-French larger than the catheter to be inserted. A 14- to 18-French gastrostomy catheter is placed through a peel-away sheath into the stomach. The peel-away sheath is usually provided with the gastrostomy tube. The guidewire is removed and contrast injected to confirm the intraluminal position of the gastrostomy tube. Although the percutaneous track may be angled toward the antrum, the gastrostomy tube usually ends in the fundus of the stomach, because the fundus is more posterior and more capacious than the gastric antrum ( Fig. 19-6 ). The nasogastric tube is removed at the end of the procedure and the patient returned to the ward.

Aftercare

Begin tube feeding after 12-24 hours. Gastrostomy tubes should be flushed thoroughly after each feeding to prevent clogging. This is particularly important after administration of crushed tablets through the tube. If clogging occurs, it can be treated by gentle flushing with hot water to dissolve impacted material. The T-fasteners are cut at 2-5 days and allowed to fall into the stomach. This is simply performed by cutting the nylon suture underneath the cotton wool pledget on the anterior abdominal wall. A new T-fastener device made by Kimberly Clark has a biodegradable suture that does not have to be cut.

In the author’s unit, gastrostomy catheters are not fixed to the skin because there is usually an internal fixation device on the catheter that prevents catheter dislodgment. The catheter entry site is simply covered with a sterile dressing. Suturing of the catheter to the skin may cause skin irritation and skin breakdown particularly, if there is any leakage around the tube.

Special Considerations

Computed Tomography Guidance

The author occasionally uses CT guidance for percutaneous gastrostomy in patients with no safe percutaneous access route to the stomach by means of standard fluoroscopic guidance, in patients in whom a nasogastric tube cannot be placed owing to esophageal obstruction, and in patients with very scaphoid abdomen in which the stomach is tucked up underneath the rib cage. In addition, CT is often used in patients who have failed PEG because of poor transillumination from the stomach to the anterior abdominal wall. In the latter situation, use of CT is often prudent to outline the relationships of the stomach to the anterior abdominal wall. Also, in patients who have undergone previous gastric surgery, CT guidance may be necessary to place the tube. CT guidance is used in a minority of patients and the routine use of CT is unwarranted.

If CT guidance is used, the patient is placed supine on the CT table and a radiopaque grid placed on the anterior abdominal wall overlying the stomach. When the stomach is located, a safe path is chosen to place the initial needle. If a nasogastric tube has not been placed in the stomach and the stomach is not distended, it may be possible to distend the stomach somewhat by giving carbonated granules to the patient before the CT procedure. If nasogastric tube placement is not possible or if carbonated granules cannot be given, a 22-gauge Chiba needle is placed into the stomach and contrast injected to confirm an intraluminal position. Air is then injected through the 22-gauge needle to distend the stomach. A 0.018-inch guidewire is placed through the needle into the stomach and a 5-French introducer sheath is placed over the guidewire with a final exchange made for a 0.038-inch J-guidewire. The patient is then moved so that fluoroscopy may be used for the remainder of the procedure ( Fig. 19-7 ).

Although CT guidance is necessary only in a minority of patients, it solves the anatomic or other impediments that make patients unsuitable for fluoroscopically guided gastrostomy.

The Postoperative Stomach

A previous subtotal gastrectomy is considered a relative contraindication to percutaneous gastrostomy. However, a number of techniques have been described to place gastrostomy tubes percutaneously in these patients. One of the problems with patients who have Billroth II procedures or gastrojejunostomies is that air insufflated into the stomach almost immediately passes into the small bowel. In these patients it is useful to give glucagon or hyoscine butyl bromide to paralyze the stomach and small bowel. In general, the procedure can be performed under fluoroscopy. Lateral fluoroscopy is helpful to assess the position of the stomach remnant vis-à-vis the anterior abdominal wall. Giving barium before the procedure helps localize the colon. If a safe access is visualized, then the procedure is carried out under fluoroscopy. If not, CT guidance is used (see Fig. 19-7 ). Some authors have described the placement of a large balloon into the stomach remnant, wherein the balloon is inflated and direct puncture of the balloon is used to obtain initial percutaneous access. In the author’s unit, we use a technique similar to that used for a standard gastrostomy. Cephalocaudal angulation of the x-ray tube can help substantially in accessing a small stomach that lies subcostally. Sometimes the body of the stomach can be entered directly with a needle; on other occasions the efferent small bowel loop is punctured and the catheter tip ultimately positioned in the gastric remnant.

In general, gastric remnants that have previously been operated on are relatively fixed in the abdomen owing to postoperative fibrosis and adhesions. T-fasteners are therefore not generally used. Once access to the stomach is gained with a one-stick needle system, the track is dilated and a 12- to 14-French nephrostomy type catheter is placed in the gastric remnant.

Results

Technical success rates of 98%-100% have been reported in several large series describing percutaneous gastrostomy ( Table 19-1 ). In one metaanalysis of the literature by Wollman and associates, the average success rate of percutaneous gastrostomy tube placement was 99.2% in a combined series of 837 patients ( Table 19-2 ). This compares favorably with a 95.7% success rate for placement of PEG tubes and 100% for surgical gastrostomy tube placement. By and large, percutaneous gastrostomy has become a widely accepted technique for gastrostomy tube placement and compares favorably with the endoscopic technique. The advantage of percutaneous gastrostomy over other techniques includes the ability to perform a percutaneous gastrojejunostomy at the time of initial tube placement, conversion of existing gastrostomy tubes to gastrojejunostomy tubes, and the ability to perform a gastrostomy in those patients with esophageal strictures through which an endoscope cannot pass.

Complications

Complications are described as major or minor as in the surgical literature. Minor complications include dislodged or leaking tubes and superficial wound infections requiring skin care. Major complications include wound-related problems (e.g., major infection, septicemia), aspiration, peritonitis, other gastrointestinal complications (perforation, hemorrhage), and dislodgment of the tube ( Fig. 19-8 ) requiring a repeat procedure. From Wollman’s metaanalysis of the literature, the complication rate for percutaneous gastrostomy is quite low in these categories. The complication rates are listed in Table 19-2 . Additionally, complication rates in two of the largest series in the radiologic literature are also quite low. In the series by Bell and associates, a major complication rate of 1.3% was seen in a total of 519 gastrostomy procedures; the minor complication rate was 2.9% (see Table 19-1 ). The major complication rate included four patients with peritonitis, two with hemorrhage requiring blood transfusion, and one with external leakage of gastric contents. In a second series by Ryan and associates, a major complication rate of 1.9% was seen in 316 consecutive patients with a minor complication rate of 3.2% (see Table 19-1 ).

Procedure-related complications can be minimized by careful attention to detail. Prior opacification of the colon and avoiding the location of the superficial epigastric artery can help avoid colonic perforation and hemorrhage, respectively. Adequate gastric distention at all times is mandatory to avoid losing access to the stomach during the procedure. Performing a gastropexy may help decrease the incidence of guidewire buckling and dislodgement of the gastrostomy tube into the peritoneal cavity. Postprocedural complications such as tube clogging and dislodgement generally can be managed conservatively. Adequate grinding of pills and tablets before administration helps decrease the incidence of tube clogging. Clogged tubes can be opened with either high-pressure syringes, heated water, or carbonated beverages. If the tube remains clogged, often the tube can be opened up by passing a guidewire down through the tube.

If the tube becomes dislodged it is important to have the patient return to the interventional suite as soon as possible. The percutaneous track will often close over within 24-48 hours depending on the maturity of the track. If the patient comes to the interventional suite soon after catheter dislodgment, it is usually possible to regain access to the stomach using a combination of a Kumpe catheter and hydrophilic wire. A new catheter can then be placed. The referring clinician should be advised to replace the tube if it does fall out at night or over a weekend so that the percutaneous track is kept open until a new tube can be placed the following morning. The patient is not fed through the replaced tube until it is checked or replaced.

Wound infection may occur with any percutaneous procedure. Management depends on the extent. Minor edema can be treated with frequent dressing changes and wound cleansing. More significant cellulitis requires antibiotic therapy.

Leak of gastric contents around the tube is a rare phenomenon. However, when it does occur it may lead to marked skin irritation, infection, and skin breakdown. The combination of wound toilet, application of an antacid solution around the stoma, and upsizing the tube all help to control the skin irritation and breakdown. Occasionally, none of these procedures work and the tube may have to be removed, particularly if the skin breakdown is severe ( Box 19-4 ).

Placement of Endoscopic Catheters

Recently, modifications of the percutaneous gastrostomy technique have been employed. Unfortunately, existing gastrostomy catheters are derived from either “abscess drainage” catheters or “Foley”-type balloon catheters. Both are associated with the long-term complications of catheter clogging or dislodgment. Consequently, some authors have embarked upon the placement of the more robust endoscopic gastrostomy tubes using a percutaneous approach. In general, the “pull” type endoscopic gastrostomy catheters are used. The stomach is punctured and a guidewire is placed in the stomach. A 5-French angiographic catheter is placed over the guidewire and used to cannulate the esophagus. The catheter and guidewire are brought out through the mouth. If the esophagus cannot be cannulated from below, a snare can be used to pull the guidewire out of the stomach, into the esophagus, and out through the mouth. The pull type endoscopic gastrostomy catheter is then pulled from the mouth down through the esophagus and out through the anterior abdominal wall. A pull type gastrostomy tube is more secure and durable, and is less likely to occlude than radiologic counterparts. Disadvantages include seeding of metastases from oropharyngeal or esophageal tumors, potential risk of infection, and the need for two operators to perform the procedure.

Primary Button Gastrostomy Placement

Button gastrostomy catheters have been widely used in the pediatric population where the low-profile nature makes them esthetically pleasing. A major disadvantage of the “button”-type catheter is the fact that a mature track of at least 3 months is advised before insertion of a gastrostomy button. The author’s unit has recently embarked upon primary button gastrostomy catheter placement using a percutaneous technique.

There are two types of retaining devices used in button gastrostomy catheters. One uses a “mushroom”-retaining device (Abbott Laboratories, Abbott Park, Ill.) while the other uses a “balloon” (Cubby, Corpak, Wheeling, Ill.; and Mic-Key, Ballard Medical Products, Draper, Utah) ( Fig. 19-9 ). We have not been able to place the mushroom-type button without having a mature track; we have placed the balloon retention gastrostomy button in more than 100 patients.

Fourteen-, 16-, or 18-French gastrostomy button catheters can be placed radiologically. The patient preparation is similar to that for standard gastrostomy catheter insertion. T-fastener gastropexy is mandatory for primary button gastrostomy catheter insertion. Accurate measurement of the track length is essential for button placement. When the stomach has been punctured and a superstiff guidewire placed, the track length can be measured by using an angioplasty balloon catheter, which is inflated within the stomach and pulled back until it abuts the anterior abdominal wall. The operator then holds the shaft of the catheter between the thumb and forefinger at skin level. The balloon catheter is then deflated and the balloon is withdrawn over the guidewire until it is fully visible. The balloon is then reinflated and the distance between the proximal end of the balloon and the operator’s thumb and forefinger is measured to give the track length. In general, a button is chosen that is 5 mm longer than the track length measured (buttons vary in length from 2 to 5 cm). The slightly longer button accounts for changes in patient position, which may require extra adjustment of catheter length.

Alternatively, the track can be measured using the guidewire technique. The latter involves placing an angiographic catheter over the guidewire and into the stomach. Lateral screening is necessary to measure the track length using this method. The guidewire is pulled back until the end of the guidewire is flush with the anterior wall of the stomach. A kink is made in the guidewire at the catheter hub. The guidewire is then pulled back until the distal end of the guidewire is at the skin site. Another kink is made in the guidewire at the hub of the catheter. The distance between the two kinks in the guidewire equates to the track length.

The track can be dilated using either the balloon catheter or serial fascial dilators. To place a 14-French button, the track is dilated to 18 French; to place a 16-French button, the track is dilated to 20 French; to place an 18-French button, the track is dilated to 22 French. When the track is dilated, a small fascial dilator is placed through the button and loaded on the guidewire (6-French dilator for a 14-French button; 7-French dilator for a 16-French button; 8-French dilator for an 18-French button). Abundant sterile jelly is used to lubricate the button, which is then pushed through the track into the stomach. The balloon is inflated with 5 mL of saline, the guidewire is removed, and the dilator is pulled back into the button before contrast material is injected to confirm an intragastric position ( Fig. 19-10 ). Kimberly Clark has recently produced a kit for primary button insertion containing T-fasteners with bioabsorbable sutures, a telescoping dilator, and a short balloon catheter for track measurement.

The advantages of button catheters are many, with the most significant being the avoidance of catheter clogging due to the short tube length. Also, the low-profile nature means that confused patients cannot grip the catheter sufficiently to remove it. The main disadvantage is that because it is a balloon retention device the balloon eventually bursts. On average the balloon lasts 3-6 months. The button devices can be simply replaced at the patient’s bedside with a similar balloon retention button device. Alternatively, a mushroom-type button can be placed because the track is mature ( Box 19-5 ).