to study in vivo; function of the human esophagus. Early pioneer work in the laboratory of Charles Code, PhD, at the Mayo Clinic led the way, with studies using nasogastric intubation with small (2–5 mm diameter) catheters in both healthy volunteers and patients with symptoms likely related to esophageal motility abnormalities. These studies were performed in awake, non‐sedated patients with a limited number of swallows (traditionally 10) of 5 ml volumes of water or saline, using a catheter filled with water or a small air‐filled balloon.
In the 1950s and 1960s, a growing group of enthusiastic investigators joined the ranks of Code’s disciples, expanding awareness of manometric findings in patients presenting with dysphagia, regurgitation, heartburn, or chest pain so that by the end of the twentieth century, the terms esophagology and esophagologist were often seen. This was stimulated by their use at the regular international meetings for studies of the esophagus organized every two to four years by professor Robert Guilli, a Parisian surgeon. At one of these, he organized an election such that I was voted by my international colleagues to receive the title “Pope of Esophagology.” Although it was created in jest, I have enjoyed the respect it carries for many years. I believe that an esophagologist is best defined as a basic or clinical scientist with a focus on studies of esophageal function or disease.
The early and subsequent group of us included Ray Clouse, Wylie Dodds, Sidney Cohen, Peter Kahrilas, John Dent, Charles Pope, Prakash Gyawali, Radu Tutuian, and Marcelo Vela. It was my good fortune during those years to work with my co‐editor, Joel Richter, who became my academic inspiration. In this case, the mentor clearly became the mentee.
These clinical investigators were joined by an enthusiastic group of basic scientists including Raj Goyal, Norman Weisbrodt, Nick Diamant, Andre Smout, Ravinder Mittal, and Jim Christenson. In the early years, we had our annual informal meeting of the “gullet club” on Monday of DDW in the bar at one of the participant hotels, usually starting after 9 p.m. From these humble beginnings, the American Neurogastroenterology and Motility Society (ANMS) has emerged.
I was often amazed at the growth and popularity of the gullet club. Over the years, I have come to appreciate the two essential reasons for the emerging legions of esophagologists: it is not simply due to a groundswell of interest in the organ but rather its ready accessibility by a simple nasogastric intubation that allows access to GI tract smooth‐muscle responses. Additionally, one should not underestimate the value of functional evaluation of an organ that performs “on‐demand” in response to a swallow. The continued popularity of studies on physiology and pathophysiology remains satisfying as new technologies and potential therapies are developed. At present, there is great enthusiasm for the technique of per‐oral endoscopic myotomy (POEM) as therapy for complicated esophageal dysmotility. I hope the world’s esophagologists will remember what history has taught us about the devastating reflux that can result from an overly zealous myotomy at the esophagogastric junction and respect the relation of enthusiasm over time for new and evolving diagnostic or therapeutic approaches such as POEM.
It has been a pleasure to observe and participate in the evolution of technology in the field, from Dr. Code’s fluid‐filled catheters and hand‐me‐down recording devices to solid‐state high‐resolution manometry with computer‐driven analysis programs. The thoughtful and focused work by John Pandolfino and Peter Kahrilas has championed an international consensus group to classify the results of studies obtained using this new technology.
We are perpetually grateful to the late Ray Clouse for the early development of high‐resolution technology. We have come a long way!
About the Companion Website
This book is accompanied by a website containing:
All figures from the book available to download in PowerPoint
www.wiley.com/go/richter/esophagus6e
1 Symptom Overview and Quality of Life
John W. Jacobs Jr.
Joy McCann Culverhouse Center for Swallowing Disorders, Divisions of Digestive Diseases and Nutrition, University of South Florida, Tampa, FL, USA
Introduction
Esophageal diseases can be congenital in etiology, or develop slowly and manifest symptoms later in life. They are also not “new world” diseases. Heartburn was described in the first century AD by the naturalist Pliny the Elder, who recommended the use of coral powder, which contains calcium carbonate. Galen, a Greek who became one of the Roman Empire’s most famous physicians, first described esophagitis in the second century AD [1]. Now, over 2000 years later, esophageal diseases continue to be a significant source of symptoms for patients worldwide. These symptoms not only span geographic borders, but also account for significant healthcare utilization in the form of ambulatory care clinic visits, over‐the‐counter and prescription medication usage, endoscopic procedures, and, for some patients, surgical intervention. As the only gastrointestinal organ in the thoracic cavity, the esophagus is unique in that not only may diseases manifest as more straightforward typical symptoms, but there can also be significant overlap with symptoms that emanate from adjacent organs, which may be cardiac, pulmonary, or otolaryngologic in etiology.
In this chapter, we will start with a description of esophageal anatomy and how esophageal symptoms may develop. This will be followed by a discussion of the most common symptoms that are attributed to the esophagus. Lastly, we will address the effect that esophageal symptoms have on the patient’s quality of life (QoL).
Esophageal anatomy and production of symptoms
Anatomy
The esophagus is a highly distensible muscular tube that moves food from the pharynx to the stomach. The upper esophageal sphincter (UES) opens for 1.5–2 seconds, allowing food to enter the esophagus, where esophageal body peristalsis propels the food downward. The lower esophageal sphincter (LES) then opens, allowing the food to move into the stomach. This occurs at the esophageal hiatus, the margin of which is formed by the right and left diaphragmatic crura, and which is located approximately 2–4 cm below the diaphragm. While essentially a midline structure, the esophagus is not quite a straight organ, and its upper portion is positioned to the left of midline, the mid portion to the right of midline, and the lower portion back to the left of midline. There are also four potential areas of normal constriction, two of which are due to its proximity to adjacent organs: the cricopharyngeus, aortic arch, left main bronchus, and LES [2]. The esophagus is fixed only at two locations, on its proximal and distal edges. The upper esophagus is attached to the cricoid cartilage, and the lower esophagus is attached via the phrenoesophageal ligaments. This distal attachment point allows for the formation of a tight seal between the abdominal and thoracic cavities, and the lack of fixation along the length of the esophagus allows the organ to possess both transverse and longitudinal mobility.
Esophageal muscle and sphincters
The esophagus has two types of muscle. The proximal one‐third of the esophagus is composed of skeletal muscle, the middle one‐third is composed of both smooth and skeletal muscle, and the distal one‐third is only smooth muscle. The muscle is arranged in two layers. The outer layer of muscle fibers runs longitudinal to the esophagus, while the second inner layer encircles the esophagus. Effective esophageal body peristalsis results from the coordinated contractile waves from both layers. Longitudinal muscle contraction moves ahead of circular muscle contraction and leads to esophageal shortening and localized luminal distension at the level of the food bolus. Circular muscle