Pneumatic dilation aims at disrupting the LES by forceful dilation using air filled balloons. This procedure has become easier and more standardized with the development of the Rigiflex balloon system (Boston Scientific Corporation, MA, USA). These are noncompliant polyethylene balloons available in 3 diameters (3.0, 3.5 and 4.0 cm), on a flexible catheter that can be placed over a guidewire at endoscopy. The catheter within the balloon has radiopaque markers which can help identify its location at fluoroscopy. Briefly, the procedure is done at the time of endoscopy, with the balloon placed over the guidewire and positioned across the LES. This position is confirmed either by fluoroscopy or endoscopy. The balloon is then gradually inflated until the waist, caused by the spastic LES, is flattened or effaced. The pressure required is usually 7-12 psi of air, held for 15-60 seconds. Sometimes multiple balloon distensions are done at the same setting. Some investigators only perform one dilation,22
but most use a graded dilation protocol starting with 3.0 cm, followed by 3.5 cm and then 4.0 cm balloon dilation, in subsequent sessions.24
A few European centers perform serial progressive dilations over several days, until the manometrically measured LES pressure is below 10-15 mmHg.22,23
Pneumatic dilation is now routinely done in outpatient centers, with the patient being observed for up to 6 hours, to ensure that no complications have occurred. Some perform Gastrografin followed by barium swallows to exclude perforations; others do not recommend obtaining routine barium X-ray films unless clinically indicated.
summarizes the good to excellent symptom relief with the Rigiflex balloons in 1,144 patients.25
These 24 studies, with an average follow-up of 37 months, found that the clinical response improves in a graded fashion with increasing size of the balloon diameter - good to excellent response in 74%, 86% and 90% with the 3.0, 3.5 and 4.0 balloons, respectively. Over a third of achalasia patients treated with pneumatic dilation will experience symptom recurrence during a 4 to 6-year period of follow-up. Long-term remission can be achieved in virtually all of these patients treated by repeated pneumatic dilation according to an "on demand" strategy, based on symptom recurrence.26
Therefore, in clinical practice, pneumatic dilation is a non-surgical treatment that will require periodic "touch ups" over the life of the patient. Pneumatic dilation is the most cost effective method for treating achalasia, when compared to Heller myotomy or Botox, over a time period of 5 to 10 years.27,28
Long-term Efficacy and Complications of Rigiflex Balloon Dilation Versus Heller Myotomy for Achalasia
With the standardization of the Rigiflex balloons, we are beginning to define the risk factors for relapse after pneumatic dilation (). These are mainly young age (< 40 years), male gender, single dilation with a 3.0 cm balloon, posttreatment LES pressure > 10-15 mmHg, and poor esophageal emptying on timed barium swallow. The effects of age on the success of pneumatic dilation are most reproducible from as far back as 1971, even with the older balloons.29
For example, Eckardt et al,30
using a 4 cm Brown-McHardy dilator, demonstrated a 5-year remission rate of 16% for patients younger than 40 years, compared to 58% for those older than 40 years. Recent studies suggest young men do not do as well as young women with the pneumatic dilation. In a study of 126 patients, Ghoshal et al31
found that male gender, but not age, was independently associated with poor outcome after dilation. Another large study from the Cleveland Clinic (106 patients, 51 women) confirmed the importance of age but also found gender to be equally important.32
Men, up to age 50 years, did not do well with a single 3.0 cm Rigiflex pneumatic dilation. However, only young women (< 35 years of age) did poorly with pneumatic dilation, while most older women had sustained relief over at least 5 years with a single pneumatic dilation.
Pneumatic Dilation: Predictors of Relapse
Physiologic studies can also predict the long-term success rate of pneumatic dilation. Eckhardt and colleagues22
reported that all patients with post procedure LES pressure < 10 mmHg were in remission after 2 years, compared with 71% for pressures between 10-20 mmHg and 23% for pressures over 20 mmHg. More recently, the Leuven group observed that 66% of their patients with post procedure LES pressure < 15 mmHg were in symptomatic remission after an average of 6 years.23
Using the timed barium swallow, we found that patients with complete symptom relief, correlating with marked improvement of esophageal emptying, were more likely to do well at 3 years than those with symptom relief, but poor esophageal emptying (82% vs 10%, respectively).21
A randomized clinical trial of pneumatic dilation versus surgery found that patients with < 50% improvement in the height of the barium column at 1 minute post treatment had a 40% risk of treatment failure during follow up.33
Most recently, the Northwestern group observed that patients with Type II achalasia pattern (esophageal pressurization) on high resolution manometry were more likely to respond to any therapy (Botox 71%, pneumatic dilation 91% and Heller myotomy 100%), compared to Type I (56% overall) and Type III (29% overall).16
This was a single center study whose authors are enthusiastic about high resolution manometry, therefore, confirmation by other centers of excellence are needed.
The only absolute contraindication to pneumatic dilation is poor cardiopulmonary status or other comorbid illnesses preventing surgery, should an esophageal perforation occur. Some have suggested that patients with vigorous achalasia, achalasia associated with epiphrenic diverticulum or hiatal hernia, malnutrition, or more than 1 previous dilation may have an increased risk of perforation. However, a retrospective study of 237 patients found no difference in clinical, endoscopic, manometric or radiographic characteristics among 7 who had perforations, compared to the 230 who did not.34
Pneumatic dilation can be safely done after a failed Heller myotomy, although larger diameter balloons are required (I usually start with a 3.5 cm balloon) and the success rate is not as good.35
The most serious complication from pneumatic dilation is esophageal perforation, with an overall rate in experienced hands of 1.9% (range 0%-16%).25
Treatment may be conservative with antibiotics and total parenteral nutrition, or surgical repair through a thoracotomy may be required. Other minor complications include chest pain (15% of patients), aspiration pneumonia, hematemesis, fever, esophageal mucosal tear and hematoma. Severe complications of gastroesophageal reflux disease (esophagitis, peptic stricture and Barrett's esophagus) are rare after pneumatic dilation, but 15%-35% of patients have heartburn, responding to proton pump inhibitors.25