REFLUX IN UNTREATED ACHALASIA PATIENTS

We made a prospective assessment of acid exposure in the distal esopha gus in 48 consecutive untreated patients with achalasia using 24-h amb ulatory esophageal pH studies. The majority of patients (38/48) experi enced reflux that was within reported values for normal controls (tota l time pH < 4.0, 1.8 +/- 1.9%). Approximately 20% (10/48), however, de monstrated abnormal acid exposure (total time pH < 4.0, 18.8 +/- 14.8% ). The difference in reflux expressed by these two groups was not due to a significant difference in lower esophageal sphincter pressure (p > 0.05) or retained food. An in vitro model of lactobacillus fermentat ion supported the contention that true acid reflux accounted for chang es in esophageal pH. Repeat pH studies were obtained in 23 patients fo llowing treatment: 15 underwent pneumatic dilatation and 8 underwent l imited myotomy. Although no significant differences were found between pre- and posttreatment reflux, some patients undergoing either treatm ent were found to demonstrate increased acid exposure. In conclusion, we believe that patients with achalasia should be tested by pH study b oth before and after treatment. Most of the patients who demonstrated significant pretreatment reflux were asymptomatic, and both methods th at were used to decrease resting sphincter pressure were shown to be a ble to increase distal acid exposure.