Technique

In general, the technique of fluoroscopically guided balloon dilation is the same for most strictures of the gastrointestinal tract. Before the procedure, a contrast-enhanced study is obtained to visualize the stricture. We prefer to use a barium suspension as contrast medium because it usually allows better delineation of the stricture than does a water soluble contrast agent. Premedication with analgesic and/or sedative generally makes the patient more comfortable during the procedure. In cases in which the oral passage of the catheters is necessary, the patient's throat is sprayed with a topical anesthetic. Salivary secretions can be reduced with atropine sulfate or removed by means of continuous oral suctioning.
A shortened 10 to 14 French feeding tube (Argyle, St. Louis, MO) is passed into the gut until it reaches the stricture. An angiographic guide wire is then inserted through the feeding tube and advanced under fluoroscopic control to cross the stricture. It is recommended that a guide wire with a J-shaped tip be used in most circumstances. In those instances, when the center of the stricture is not in the longitudinal axis of the gut but is at an angle, or when there are multiple strictures it may be necessary to manipulate the feeding catheter or use a curved angiographic catheter to direct the wire into the orifice of the stricture.
The guide wire needs to be advanced well beyond the stricture to provide a stable purchase for catheter exchange. Then the feeding tube/catheter is removed and a Gruntzig-type polyethylene balloon catheter (Medi-tech, Watertown, MA.) is advanced over the guide wire. The diameter of the chosen balloon depends on the diameters of both the stricture and the adjacent normal gut. Generally, the dilation of very narrow strictures is initiated with a small balloon. If partial dilation is easily achieved, the procedure is continued with balloons of larger diameter until the desired result is achieved.
To dilate the stricture, the balloon is positioned so that its midportion straddles the narrowing. The balloon is inflated under fluoroscopic control with water soluble contrast medium [diatrizoate meglumine (Renografin 30%, Bracco Diagnostics,Inc., Princeton, NJ)] to opacify its lumen. As the balloon begins to inflate, a waist-like contour is usually noted at its middle. This appearance corresponds to the stricture. The balloon is slowly inflated until the "waist" disappears. In many cases, it may not be possible to stretch the stricture completely at the first inflation. In these cases, the balloon is inflated until resistance is felt. This inflation pressure is maintained for 30-180 seconds and monitored by an in-line pressure gauge. After the initial dilation, the balloon is deflated for approximately one minute and subsequently reinflated for additional 30-180 second periods.
Inflation is repeated as many times as necessary to obtain full distention of the stricture. With each inflation, the balloon pressure is increased by small increments (usually 1 atmospheres) until either maximum distention or balloon pressure tolerance (about 3 atmospheres in the larger balloons) is achieved. In our experience, performing multiple balloon inflations with small incremental increases in pressure during the course of the procedure is preferable to dilating the stricture with one balloon inflation to maximum pressure. We believe that the latter method significantly increases the risk of perforation increases. During each inflation, the balloon is watched fluoroscopically to ascertain that no complications are occurring.
When maximum distention of the gut is achieved and the stricture is maximally dilated, the balloon is deflated, and the guide wire withdrawn. The total number of inflations during each procedure varies but may range from 3 to 5. Then the wire is withdrawn, and the balloon catheter is withdrawn slightly from the stricture. Barium suspension is injected under fluoroscopic control through the central lumen to determine the presence or absence of a possible leak or laceration. Frequently, the stricture appears unchanged in appearance from the preprocedural barium examination; however, the clinical response of the patient is the most important factor in determining the ultimate success or failure of the procedure.
A complicating perforation that occurs during the procedure may be suggested by an abruptly disappearing "waist" on the balloon and a sudden drop of the inflation pressure. When such a complication is suspected, the balloon is immediately deflated, and the guide wire that was still present in the central lumen of the balloon is removed. The balloon is then slightly withdrawn so that the tip is just above the stricture and suspected leak. Water soluble contrast medium is then injected through the central lumen of the balloon catheter to search for the possible leak. If no leak is demonstrated, the contrast study is immediately repeated using a dilute barium suspension. Suspected leaks of the gut below the diaphragm are evaluated only with water soluble contrast medium because of the lower incidence of complications if spillage occurs into the abdominal cavity.
When carefully performed, the risk of a perforation occurring during a fluoroscopically controlled balloon dilation is very low. In our experience with more than 900 patients, we have had complications in fewer than 2% of cases. In most of these cases, minor mucosal tears were seen on the postprocedure barium examination, and only one patient required surgical treatment. The risk of perforation is higher with endoscopically performed balloon dilations and is reported to range between 0.9-5%. Because a postprocedure barium examination is usually not obtained after an endoscopically guided dilation, the actual number of tears is unknown, but it is probably much higher than is reported, as only the patients with significant perforation come to the physician's attention. Since a fluoroscopically guided dilation procedure can be more carefully monitored, it has clearly a major advantage over the endoscopic method.