GI Dilation

Esophagus

Esophageal dilation may be performed to treat benign strictures (i.e. peptic strictures, Schatzki's Ring, achalasia) or intrinsic/extrinsic malignant esophageal strictures. Dilation of the esophagus is typically performed with a polyvinyl bougie (rigid dilator) or with a balloon dilator. In a randomized study of 34 patients (17 in each treatment arm), Saeed et. al. found that during the second year post-procedure the risk of stricture recurrence was significantly lower in patients whose strictures were dilated with balloons.³ Other advantages of balloons included the need for fewer treatment sessions to achieve the defined end-diameter for dilation (1.1 + 0.1 versus 1.7 + 0.2, p < 0.05) and less procedural discomfort (p < 0.05).³

Balloon dilation is sometimes used to dilate malignant esophageal strictures prior to staging with EUS. According to a multicenter retrospective study, among 215 consecutive EUSs, dilation was required in 71 (33%). All dilations were done with CRE™ Balloon Dilators. In this retrospective study, there were 2 perforations. One perforation occurred following dilation with a balloon (1.4%) to 16.5mm in a 6cm long T3N1 tumor. The other perforation occurred following EUS without dilation (0.7%). The authors note that other published data demonstrates a 3% perforation rate when using bougienage for esophageal cancer dilation.⁴

Pyloric Region

Peptic ulcer disease (PUD) is a common disease that affects approximately 20 million Americans.⁵ PUD may be caused by a bacterial infection (Helicobacter pylori or H. pylori) or from ingestion of anti-inflammatory drugs (such as aspirin and ibuprofen).⁵ In a study of benign gastric outlet obstructions caused by peptic strictures, with and without H. pylori, balloon dilation was shown to reduce ulcer complications in the treatment of H. pylori.⁶

Colon

Strictures in the colon can be caused by many diseases, such as Crohn's Disease or inflammatory bowel disease (IBD). Gastrointestinal strictures can be a serious complication in Crohn's disease.⁷ According to a study by Toshiyuki et. al., endoscopic balloon dilation may be a better long-term therapeutic option for the treatment of Crohn's strictures than surgery.⁷ In this prospective study of balloon dilation on 68 patients with gastroduodenal and intestinal strictures, 55 patients did not need surgery within 6 months post-dilation. Thirty patients were able to avoid surgery.⁷ Toshiyuki et al. conclude that endoscopic balloon dilation (EBD) therapy for Crohn’s stricture in the gastrointestinal tract is recommended before surgical intervention.⁷

Advantages of Using a Balloon Dilator

Balloon dilators may offer a number of potential advantages versus rigid technologies when performing dilation, including:³

• Direct endoscopic visualization
• Application of radial force directly to the stricture site
• Improved patient comfort

Balloon dilators are designed to be used through the scope (TTS) and are available in wire-guided or non-wireguided (fixed wire) versions. These balloons are expanded via pressure injection of liquid (e.g. saline, water, radiopaque contrast). Some balloons are designed to expand to a single diameter while others are designed to inflate to multiple diameters.

Multi-Diameter Balloon Dilators

In 1998, Boston Scientific introduced its first multi-diameter balloon dilator. The patented and proprietary CRE™ Balloon Dilator is a through-the-scope multi-diameter controlled radial expansion balloon dilator. It is designed to deliver 3 distinct, pressure-controlled diameters in 1 balloon at 3 separate pressures during in-vivo dilation at body temperature. Since 3 sizes can be achieved with 1 balloon pass, the procedure is potentially shorter and less expensive than dilation with a single-diameter balloon.⁸

Boston Scientific manufactures two types of multi-diameter CRE balloon dilators. The CRE Fixed Wire Balloon Dilator is indicated for use in adult and adolescent populations to endoscopically dilate strictures of the esophagus. The CRE Wireguided Balloon Dilator is indicated for use in adult and adolescent populations to endoscopically dilate strictures of the alimentary tract (esophageal, pyloric or colonic applications).

References

1. Taber's Cyclopedia Medical Dictionary. Edition 18. F.A. Davis Company, Philadelphia, 1997, p. 545.
2. Scolapio J, et. al. A randomized prospective study comparing rigid to balloon dilators for benign esophageal strictures and rings. Gastrointestinal Endoscopy 1999; 50:13-17.
3. Saeed, Zahid A., et. al. Prospective randomized comparison of polyvinyl bougies and through-the-scope balloons for dilation of peptic strictures of the esophagus. Gastrointestinal Endoscopy 1995;41:189-195.
4. Jacobson, Brian C., et. al. TTS-Balloon Dilation for EUS Staging of Esophageal Cancer: A Multi-Center Safety Study. Gastrointestinal Endoscopy 2005;61:AB115.
5. The Cleveland Clinic. Peptic Ulcer Disease. http://cms.clevelandclinic.org/digestivedisease. Accessed August 16, 2005.
6. Lam, Yuk-hoi, et. al. Endoscopic balloon dilation for benign gastric outlet obstruction with or without Helicobacter pylori infection. Gastrointestinal Endoscopy 2004;60:229-233.
7. Toshiyuki, Matsui, et. al. Long-Term Outcome of Endoscopic Balloon Dilation in Obstructive Gastrointestinal Crohn's Disease. Gastrointestinal Endoscopy 2005;61:AB265.
8. Goldstein, Jeffrey A. and Jamie S. Barkin. Comparison of the Diameter Consistency and Dilating Force of the Controlled Radial Expansion Balloon Catheter to the Conventional Balloon Dilators. American Journal of Gastroenterology 2000;95:3423-3427.