Background: Laparoscopy has increased the number of patients undergoing operative correction of gastroesophageal reflux disease (GERD). Symptom improvement has been most commonly reported as the means to assess operative outcome. We compared symptomatic outcome to postoperative pH testing at short-term follow-up to determine the accuracy of clinical assessment at predicting whether acid exposure would be normal or abnormal.

Methods: Of 640 patients who had antireflux surgery between 1993 and 1999, 228 (36%) agreed to repeat manometry and 24-hour pH monitoring 8 to 12 weeks postoperatively and are the subject of this study. Symptom resolution was assumed if the frequency was less than once per week. Normal acid exposure consisted of a distal esophageal pH below 4 less than 4% of the time and a DeMeester composite score less than 14.7. Accuracy of symptom scoring was calculated using acid exposure as the standard.

Results: The primary symptom was improved in 93% of the 228 patients. Acid exposure was reduced from a preoperative DeMeester score of 71 to 16 (P <0.05). Eighty percent of patients had normalization of acid exposure postoperatively. Heartburn was the only symptom to have a significant correlation with acid exposure in the postoperative period (P <0.05). Heartburn resolved in 181 patients, 168 of whom had normal acid exposure (true negative). Thirty-eight patients without symptoms had abnormal acid exposure (false negative). Nine patients had persistent heartburn with abnormal acid exposure (true positive) whereas 13 patients had persistent heartburn with normal acid exposure (false positive). Thus, the positive predictive value of heartburn was 43%, the negative predictive value was 82%, and the overall accuracy was 78%.

Conclusions: Operative treatment improves both the symptoms of GERD and the degree of acid exposure as measured by pH monitoring. The most accurate symptom for predicting acid exposure in the postoperative period is heartburn. Although the absence of heartburn postopertively is fairly reliable at predicting normal acid exposure on pH testing, the presence of heartburn warrants postoperative pH monitoring, as more than half of these patients will have normal acid exposure.