Chicago Classification of Esophageal Motility Disorders: Lessons Learned.

PURPOSE OF REVIEW: High-resolution manometry (HRM) is increasingly performed worldwide, to study esophageal motility. The Chicago classification is subsequently applied to interpret the manometric findings and facilitate a diagnosis of esophageal motility disorders. This review will discuss new insights regarding the diagnosis and management using the Chicago classification. RECENT FINDINGS: Recent studies have demonstrated that high-resolution manometry is superior to conventional manometry, and has a higher sensitivity to diagnose achalasia. Furthermore, the subclassification of achalasia as used in the Chicago classification has prognostic value and can be used to direct treatment. Diagnosis of esophageal spasm has been improved by using the distal latency as diagnostic criterion. Recently, criteria for minor disorders of peristalsis have been sharpened, leading to a lower rate of patients with abnormal results, thereby increasing the relevance of a diagnosis. High-resolution manometry is now considered the gold standard for diagnosis of esophageal motility disorders. The Chicago classification provides a standardized approach for analysis and categorization of abnormalities that has led to a significant increase in our knowledge regarding the diagnosis and management of motility disorders. Further refinement of the classification will be required.

Pathophysiology and management of gastroesophageal reflux disease.

Gastroesophageal reflux is a physiological phenomenon but becomes pathological if troublesome symptoms and/or complications occur. Gastroesophageal reflux disease (GERD) has different phenotypes ranging from non-erosive reflux disease (NERD), through reflux esophagitis and Barrett's esophagus, and can present with either typical symptoms such as regurgitation and heartburn, or extra-esophageal symptoms such as cough and laryngitis. In the diagnosis of GERD endoscopy, empirical PPI test, and pH impedance testing all have their own position. Although proton pump inhibitors (PPIs) are very effective in the treatment of esophagitis, a significant proportion of patients have persistent symptoms even during high dosing of PPIs. Therefore, insight into the multifactorial pathophysiology of GERD is needed to develop new anti-reflux therapies. The predominant mechanism underlying reflux is the transient lower esophageal sphincter relaxation (TLESR). Hiatal hernia, impaired esophageal clearance and reduced lower esophageal sphincter pressure play a significant role in patients with moderate to severe reflux disease. Refluxate containing acid, pepsin and bile can cause epithelial injury when epithelial barrier of the esophagus fails to defend. In the majority of patients there is histopathological evidence of epithelial injury, even with NERD where there are more dilated intercellular spaces. The perception of heartburn can be enhanced due to visceral hypersensitivity, leading to more and more severe symptoms. Anti-reflux surgery is as effective as PPI therapy, but has higher morbidity and results decline in the long term. Therefore, new pharmacological, endoscopic and surgical interventions are being developed for these patients.

Electrical tissue impedance spectroscopy: a novel device to measure esophageal mucosal integrity changes during endoscopy.

BACKGROUND: Patients with gastroesophageal reflux disease (GERD) have impaired esophageal mucosal integrity. Measurement of the mucosal integrity is complex and time-consuming. Electrical tissue impedance spectroscopy (ETIS) is a device that measures impedance of tissue in vivo during endoscopy. In this study, we aimed to validate ETIS as a measure of esophageal mucosal integrity. METHODS: Electrical tissue impedance spectroscopy measurements were performed during upper endoscopy in 12 GERD patients and 11 healthy controls after cessation of proton pump inhibition. During endoscopy biopsies of the distal esophagus were obtained for transmission electron microscopy to determine dilation of intercellular spaces (DIS) and for Ussing chamber experiments to determine transepithelial permeability and transepithelial electrical resistance. KEY RESULTS: Extracellular impedance measured in vivo by ETIS was significantly lower in GERD patients compared to controls [mean (SD) 5621 (3299) Ω.m and 8834 (2542) Ω.m, respectively, P < 0.05]. We found a strong inverse relation between extracellular impedance determined by ETIS and DIS (r = -0.76, P < 0.05), and between extracellular resistance in vivo and transepithelial permeability of esophageal biopsies (r = -0.65, P < 0.01). CONCLUSIONS & INFERENCES: Electrical tissue impedance spectroscopy is a new tool that can be used to evaluate esophageal mucosal integrity changes during endoscopy.

High-resolution esophageal pressure topography is superior to conventional sleeve manometry for the detection of transient lower esophageal sphincter relaxations associated with a reflux event.

BACKGROUND: Transient lower esophageal sphincter relaxations (TLESRs) are the main mechanism underlying gastro-esophageal reflux and are detected during manometric studies using well defined criteria. Recently, high-resolution esophageal pressure topography (HREPT) has been introduced and is now considered as the new standard to study esophageal and lower esophageal sphincter (LES) function. In this study we performed a head-to-head comparison between HREPT and conventional sleeve manometry for the detection of TLESRs. METHODS: A setup with two synchronized MMS-solar systems was used. A solid state HREPT catheter, a water-perfused sleeve catheter, and a multi intraluminal impedance pH (MII-pH) catheter were introduced in 10 healthy volunteers (M6F4, age 19-56). Subjects were studied 0.5 h before and 3 h after ingestion of a standardized meal. Tracings were blinded and analyzed by the three authors according to the TLESR criteria. KEY RESULTS: In the HREPT mode 156 TLESRs were scored, vs 143 during sleeve manometry (P = 0.10). Hundred and twenty-three TLESRs were scored by both techniques. Of all TLESRs (177), 138 were associated with reflux (78%). High-resolution esophageal pressure topography detected significantly more TLESRs associated with a reflux event (132 vs 119, P = 0.015) resulting in a sensitivity for detection of TLESRs with reflux of 96% compared to 86% respectively. Analysis of the discordant TLESRs associated with reflux showed that TLESRs were missed by sleeve manometry due to low basal LES pressure (N = 5), unstable pharyngeal signal (N = 4), and residual sleeve pressure >2 mmHg (N = 10). CONCLUSIONS & INFERENCES: The HREPT is superior to sleeve manometry for the detection of TLESRs associated with reflux. However, rigid HREPT criteria are awaited.