Introduction

• Strictures of the gastrointestinal tract usually form as a complication of inflammation or carcinoma.  With the increasing number of surgical procedures involving the gut, the number of gastrointestinal strictures complicating the formation of a surgical anastomosis has also risen.  Whatever the cause, the strictures are usually persistent, and they may produce significant clinical symptoms.
  
  

• The standard nonoperative management of gastrointestinal strictures has been with graded dilators of progressively larger diameter.  As strictures are most common in the esophagus, treatment has been traditionally focused on this portion of the gut.  For many years, bougienage has been the standard treatment to dilate the strictures.  The more recent method of stricture dilation involves the use of balloon catheters with fluoroscopic guidance.  This technical advance became feasible only after the introduction of a double-lumen catheter with a low-compliance balloon, originally intended for transluminal angioplasty.  This device permits generation of high pressure in the balloon while maintaining a fixed balloon diameter.
  
  

• Balloon dilation offers a number of advantages over bougienage.  The most important is that the balloon remains in a stationary position during inflation and applies only radially directed forces to the gut wall.  Forces are maximal at the narrowest point, the stricture itself.  In contrast, a bougie must exert considerable longitudinal force on the gut wall to generate an effective radial dilating force on the stricture.  This longitudinal shearing force increases the risk of rupture and mucosal injury which can lead to recurrence of the stenosis (Fig. 1).       

Fig. 1.  Dilation of esophageal stricture with bougie or balloon.  (A) The bougie is lowered down onto the stricture. The dilating forces are chiefly longitudinal on the gut wall (arrows).  (B) The balloon is positioned across the  stricture. During inflation, the dilating forces (arrows) are only radially directed to the gut wall resulting in more effective stretching of the stricture.  (From Shaffer & de Lange, ref. 7.  Reproduced by permission.)

• The adverse effect of the longitudinal shearing force is demonstrated by the post-dilation relapse-free interval, which averages about six times longer after balloon dilation than after bougienage in the treatment of esophageal strictures.  Another advantage of using a balloon is that dilation pressure can be monitored and controlled with an in-line pressure gauge.  Also, balloon dilation may be more comfortable for the patient than bougienage because it usually requires only a single passage of a small catheter with a collapsed balloon, whereas bougienage requires multiple exchanges for progressively larger and larger dilators.
  
  

• Fluoroscopically guided dilation has advantages over blindly performed or endoscopically controlled procedures.  When endoscopy is used to guide a dilating bougie or balloon, only the gut proximal to the stricture is visualized once the dilator enters the stricture.  Beyond that point, the instrument is passed without visual control, and perforation by the tip of the dilator can occur.  Fluoroscopy allows visualization of the stricture as well as the gut proximal and distal to it.  It also permits visual control of the entire balloon catheter during its placement and inflation (Fig. 2).  

Fig. 2.      Endoscopically guided balloon dilation of strictures in tortuous gut.
(A)  View through the endoscope positioned at the stricture in the gastrointestinal tract shows only the orifice of the stricture.
(B)  The tortuosity of the gut more distally is not seen endoscopically. When the balloon is advanced, the orifice becomes obscured.  E = endoscope.
(C)  View through the endoscope with the balloon in the stricture.  Only the proximal portion of the balloon is visible to the examiner and there is no control of the tip of the catheter.
(D)  When the balloon catheter is advanced, a perforation can easily occur and is likely to go unnoticed as the tip of the catheter is not visible to the examiner.  (From Shaffer & de Lange, ref. 7.  Reproduced by permission.)