CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2011;9:1020 1024 REVIEWS Erroneous Diagnosis of Gastroesophageal Reflux Disease in Achalasia BOUDEWIJN F. KESSING, ALBERT J. BREDENOORD, and ANDRÉ J. P. M. SMOUT Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, Amsterdam, The Netherlands See editorial on page 1010. BACKGROUND & AIMS: Most experienced gastroenterologists have seen one or several cases of achalasia patients who have been erroneously diagnosed with gastroesophageal reflux disease (GERD) or even underwent antireflux surgery. We aim to describe the current knowledge about the diagnostic features of achalasia and their overlap with GERD. Furthermore, we present 3 cases in which achalasia was mistaken for GERD. METHODS: Search of the literature published in English using the PubMed database and relevant abstracts presented at international conventions. RESULTS: Typical features of GERD such as heartburn, retrosternal pain, esophagitis, and pathologic acid exposure can be observed in achalasia patients. Diagnostic tests such as endoscopy and radiography lack sensitivity and specificity for achalasia. Current diagnostic guidelines for antireflux surgery do not stipulate that achalasia should be ruled out preoperatively. CONCLUSIONS: Clinical presentation as well as the diagnostic work-up of achalasia patients can show overlap with GERD. Mistaking achalasia for GERD can be avoided by esophageal manometry and this should therefore be performed in all patients undergoing surgical fundoplication. Keywords: Achalasia; Gastroesophageal Reflux Disease; Esophageal Manometry; Surgical Fundoplication. Achalasia is a rare disease with an annual incidence estimated at 1/100,000. The pathophysiology consists of a loss of inhibitory neurons of the myenteric plexus in the esophageal wall, resulting in impaired lower esophageal sphincter (LES) relaxation and dysregulation of esophageal peristalsis. Both abnormalities contribute to impaired esophageal emptying. Not infrequently, clinicians in referral centers encounter achalasia patients who have been erroneously diagnosed with gastroesophageal reflux disease (GERD) or, in rare cases, even underwent antireflux surgery. In part, this is due to limited awareness and knowledge of achalasia. Furthermore, the clinical features of achalasia and diagnostic findings can mimic those of GERD, which can render achalasia a difficult diagnosis to make. In order to increase awareness of these pitfalls, we describe 3 cases in which achalasia was mistaken for GERD. Furthermore, we aim to review the current knowledge about the diagnostic features of achalasia and their overlap with GERD. Case 1: Achalasia Presents With Heartburn A 38-year-old woman presented with typical symptoms of heartburn and regurgitation despite double-dose proton pump inhibitor (PPI) therapy. No abnormalities were seen on upper endoscopy. She was referred by an experienced gastroenterologist to our center with the specific request to perform antireflux surgery. The routine presurgical work-up in our center consists of esophageal manometry and a 24-hour ph-impedance measurement. The nurse that performed the investigation recognized a manometric pattern during the measurement that was typical of achalasia. The patient underwent endoscopic pneumodilation which successfully relieved her symptoms. Case 2: Achalasia Presents With Regurgitation A 30-year-old man was referred to our hospital by an experienced gastroenterologist who suspected nonerosive reflux disease or rumination syndrome. This patient presented with postprandial regurgitation of undigested food without nausea or vomiting. He also experienced short episodes of postprandial retrosternal and epigastric pain, which he described as heartburn, that did not respond to any PPI. When specifically asked about dysphagia, he confirmed that he incidentally experienced this symptom for solids and liquids. Upper endoscopy, performed in the referring hospital, showed a small hiatal hernia but no esophagitis. In our center, a 24-hour ph-impedance measurement was carried out. Computer analysis showed an acid exposure time (% time ph 4) of 7.8% (0.7% upright, 14.7% supine) which suggests pathologic supine reflux. Manual analysis of the ph measurement revealed that this acid exposure time was mainly due to postprandial stasis of acidic food when the patient lay down after the meal. The manometry which was performed to allow placement of the ph electrode before the ph-impedance measurement revealed achalasia. Case 3: Achalasia Develops in a GERD Patient A 52-year-old woman was known with a short-segment Barrett s metaplasia for which endoscopic surveillance was con- Abbreviations used in this paper: GERD, gastroesophageal reflux disease; LES, lower esophageal sphincter; PPI, proton pump inhibitor. 2011 by the AGA Institute 1542-3565/$36.00 doi:10.1016/j.cgh.2011.04.022
December 2011 ACHALASIA CAN MIMIC GERD 1021 Figure 1. Fragment of 24-hour ph measurement in a patient with achalasia. Stasis of food with acidic contents is responsible for a long episode with ph 4. ducted. She presented with progressive retrosternal pain for several years which was refractory to PPI treatment and was believed to be due to gastroesophageal reflux. However, for 1.5 years she also developed dysphagia and more recently started to lose weight. Upper endoscopy showed the Barrett s segment but offered no explanation for her symptoms. She was referred to our hospital for further evaluations. Esophageal manometry and barium swallow both showed classic achalasia. After exclusion of pseudoachalasia due to a malignancy with a computed tomography (CT) scan, the patient underwent pneumodilation which resulted in a decrease in dysphagia. However, the retrosternal pain did not completely resolve after treatment. Diagnosis History The typical achalasia patient presents with the combination of dysphagia, weight loss, and regurgitation. However, in a large subset of patients (38% 75%) heartburn is present. 1 3 Heartburn and regurgitation are typical symptoms of GERD, and dysphagia is not only encountered in achalasia but is also frequently reported by GERD patients. 4 Therefore, achalasia can present with symptoms that potentially suggest gastroesophageal reflux disease. Endoscopy The first step in the diagnostic algorithm for a patient with typical GERD symptoms such as heartburn and regurgitation that persist despite PPI therapy is upper endoscopy. 4 This will rule out complications of GERD such as esophagitis, strictures, Barrett s metaplasia, and adenocarcinoma. In achalasia patients, endoscopy can show esophageal dilation and retention of food or fluids and suggest the diagnosis. However, if endoscopy is performed in an achalasia patient with symptoms of heartburn and regurgitation, the correct diagnosis is made in only 30% of the cases. 5 Probably, achalasia will be more often missed with endoscopy in early cases of the disease when esophageal dilation has not yet occurred. Sensitivity will most likely increase in longstanding achalasia. Whereas esophagitis is considered objective proof of GERD, 6 esophagitis is also found in 8% to 12% of untreated achalasia patients. 2,5 ph Measurement If patient history and endoscopy show no abnormalities and a patient has persistent symptoms of heartburn and regurgitation despite PPI, the next diagnostic step is often a 24-hour ph-measurement. Pathologic acid exposure times during ph measurement have been described in 20% of achalasia patients. Furthermore, achalasia can develop in patients with a previous diagnosis of GERD. The episodes of esophageal acid exposure in achalasia are not always due to actual reflux. Achalasia patients have esophageal stasis of food or beverages and, when these contents are acidic, this may mimic acid gastroesophageal reflux 1 (Figure 1). Impedance Measurement Impedance measurement is a relatively new diagnostic tool to measure gastroesophageal reflux of fluid and gas. A growing number of centers perform impedance measurements as part of their routine investigations. In achalasia patients, very low baseline impedance tracings are often found which are due to stasis and/or due to damage to the esophageal wall 7,8 (Figure 2). However, low baselines are also often seen in GERD patients. Radiography A barium esophagogram (barium swallow) is rarely used in GERD patients, however, when a patient has symptoms of dysphagia, a barium examination can be used to detect subtle strictures and rule out a paraesophageal hernia and to assess esophageal transit. In achalasia patients, barium swallow can show dilation of the esophagus, absent peristalsis, and narrowing of the distal esophagus, often referred to as a bird s beak. Despite the fact that radiography can be strongly suggestive of achalasia, only 64% of barium examinations in achalasia patients suggest achalasia. 5 Notably, the same authors describe that the sensitivity of radiology to detect achalasia was even lower in the referring hospitals. 5 Manometry The current gold standard to diagnose achalasia is esophageal manometry. 9 Classic achalasia is characterized by incomplete relaxation of the LES and aperistalsis in the body of the esophagus (Figure 3). Characteristics that are not required for the diagnosis but often observed in classic achalasia are an elevated resting LES pressure and an elevated resting pressure in the esophageal body that exceeds gastric pressure. Whereas conventional esophageal manometry using single pressure points and a water-perfused sleeve sensor have been used for a long time, high-resolution manometry is currently becoming increasingly popular to assess esophageal function. Recent studies suggest a significant improvement in the sensitivity for the diagnosis of achalasia when compared with conventional pull-through manometry because LES relaxation can be observed more accurately 10 (Figure 4). This is in part explained by a phenomenon known as pseudorelaxation which is caused by deglutitive esophageal shortening of the esophagus. 10 Furthermore, high-resolution manometry has prompted the recognition of 3 different subtypes of achalasia which have different therapeutic outcomes. 11 However, it can be argued that these subtypes can also be recognized with conventional manometry.
1022 KESSING ET AL CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Vol. 9, No. 12 Figure 2. Impedance tracing measured in a normal subject and an achalasia patient. The impedance tracings in the achalasia patients are characterized by low distal baseline impedance levels. Discussion Early recognition of achalasia is likely to offer the best chances for an adequate treatment of the obstruction, relief of the obstruction, and prevention of complications such as weight loss and dilation of the esophagus. However, achalasia can be mistaken, even by experienced clinicians, for GERD and most investigations which are performed in GERD patients can fail to identify achalasia. Especially when signs of GERD are present, such as an esophagitis or abnormal esophageal acid exposure, an erroneous diagnosis is possible. Furthermore, achalasia can develop in patients with proven GERD. The medical position statement of the American Gastroenterological Association states that manometry should be used to evaluate patients with suspected GERD who have not re- Figure 3. Classic achalasia, which is identified by absent LES relaxation and absent peristalsis as measured by conventional manometry.
December 2011 ACHALASIA CAN MIMIC GERD 1023 Figure 4. High-resolution manometry plot of classic achalasia, which is identified by the absence of LES relaxation and no peristaltic contractions of the esophagus after the onset of a swallow. sponded to an empiric trial of twice-daily PPI therapy and have normal findings on endoscopy. 12 If surgical treatment is considered, manometry serves as a preoperative evaluation of peristaltic function, and to diagnose esophageal motor disorders. In contrast, the recent guidelines by the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) state that GERD can be confirmed by demonstration of either an esophagitis, abnormal esophageal acid exposure time, Barrett s esophagus, or a peptic stricture. 6 However, all these clinical signs of GERD can be present in achalasia patients, particularly given the fact that achalasia can develop in a patient that previously had GERD. Surgical intervention is indicated when a patient has symptoms despite acid suppression. Because achalasia patients have no relief of symptoms during gastric acid suppres-
1024 KESSING ET AL CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Vol. 9, No. 12 sion, this criterion is often met in achalasia patients. According to the Society of American Gastrointestinal and Endoscopic Surgeons guidelines, there is no support in the literature for mandatory preoperative manometry, because manometric findings do not predict the outcome of surgery. However, if a surgical fundoplication is performed in an achalasia patient, a mechanical obstruction will be added to the already present functional obstruction, the dysphagia symptoms will increase, and esophageal dilation sets in. Therefore, preoperative manometry should be used to exclude esophageal motility disorders rather than as a predictor of outcome after fundoplication. We suggest that achalasia should be excluded in all patients undergoing surgical fundoplication. While there are no data available on the prevalence of inadvertently performed fundoplication in achalasia patients, most gastroenterologists will have seen one or several cases. In conclusion, the clinical presentation as well as the diagnostic work-up of achalasia patients can show overlap with GERD. Mistaking achalasia for GERD can be avoided by esophageal manometry and should be performed in all patients undergoing surgical fundoplication. References 1. Patti MG, Arcerito M, Tong J, et al. Importance of preoperative and postoperative ph monitoring in patients with esophageal achalasia. J Gastrointest Surg 1997;1:505 510. 2. Ponce J, Ortiz V, Maroto N, et al. High prevalence of heartburn and low acid sensitivity in patients with idiopathic achalasia. Dig Dis Sci 2011;56:773 776. 3. Spechler SJ, Souza RF, Rosenberg SJ, et al. Heartburn in patients with achalasia. Gut 1995;37:305 308. 4. Kahrilas PJ. Clinical practice. Gastroesophageal reflux disease. N Engl J Med 2008;359:1700 1707. 5. Howard PJ, Maher L, Pryde A, et al. Five year prospective study of the incidence, clinical features, and diagnosis of achalasia in Edinburgh. Gut 1992;33:1011 1015. 6. Stefanidis D, Hope WW, Kohn GP, et al. Guidelines for surgical treatment of gastroesophageal reflux disease. Surg Endosc 2010;24:2647 2669. 7. Agrawal A, Hila A, Tutuian R, et al. Manometry and impedance characteristics of achalasia. Facts and myths. J Clin Gastroenterol 2008;42:266 270. 8. Nguyen HN, Domingues GR, Winograd R, et al. Impedance characteristics of esophageal motor function in achalasia. Dis Esophagus 2004;17:44 50. 9. Spechler SJ, Castell DO. Classification of oesophageal motility abnormalities. Gut 2001;49:145 151. 10. Ghosh SK, Pandolfino JE, Rice J, et al. Impaired deglutitive EGJ relaxation in clinical esophageal manometry: a quantitative analysis of 400 patients and 75 controls. Am J Physiol Gastrointest Liver Physiol 2007;293:G878 G885. 11. Pandolfino JE, Kwiatek MA, Nealis T, et al. Achalasia: a new clinically relevant classification by high-resolution manometry. Gastroenterology 2008;135:1526 1533. 12. Kahrilas PJ, Shaheen NJ, Vaezi MF, et al. American Gastroenterological Association Medical position statement on the management of gastroesophageal reflux disease. Gastroenterology 2008;135:1383 1391. Reprint requests Address requests for reprints to: Boudewijn F. Kessing, MD, Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. e-mail: b.f.kessing@amc.uva.nl; fax: 31205669478. Conflict of interest The authors disclose no conflicts. Funding A.J. Bredenoord is supported by The Netherlands Organisation for Scientific Research (NWO).