Anatomy and Physiology of the Esophagus

AORN Journal, Feb, 1999 by Mary Gavaghan

The article "Anatomy and physiology of the esophagus" is the basis for this AORN Journal independent study. The behavioral objectives and examination for this program were prepared by Helen Starbuck Pashley, RN, MA, CNOR, with consultation from Trish O'Neill, RN, MS, education coordinator, Center for Perioperative Education.

A minimum score of 70% on the multiple-choice examination is necessary to earn two contact hours for this independent study. Participants receive feedback on incorrect answers. Each applicant who successfully completes this study will receive a certificate of completion. The deadline for submitting this study is March 31, 2000.

Send the completed application form, multiple-choice examination, learner evaluation, and appropriate fee to

AORN Customer Service
c/o Home Study Program
2170 S Parker Rd, Suite 300
Denver, CO 80231-5711

BEHAVIORAL OBJECTIVES

After reading and studying the article on anatomy and physiology of the esophagus, the nurse will be able to

(1) discuss the risk factors for esophageal cancer,

(2) identify the significant anatomy of the esophagus, and

(3) discuss the physiology of the esophagus.

The earliest accounts of esophageal surgery are found in the document known as the "Smith Surgical Papyrus." This document, unearthed by the American Egyptologist Edwin Smith in 1862, describes a "gaping wound of the throat penetrating the gullet." Cancer of the esophagus was recognized by the Chinese more than 2,000 years ago as a cause of dysphagia. Achalasia was first described by the English anatomist Thomas Willis in 1674. He used a cork-tipped whale bone as an instrument of esophageal dilatation.

Physicians in Germany and Austria contributed significant advances to knowledge about the esophagus and to surgical techniques in the 19th century. In 1868, a German physician, Adolf Kussmaul, hyper-extended a patient's head and neck and passed a lighted tube into the esophagus to diagnose a carcinoma of the thoracic esophagus. Another German surgeon, Friedrich Trendelenburg, introduced endotracheal anesthesia in 1869, and two years later, in 1871, the first successful esophageal resection and reanastamosis was performed on dogs by the Austrian surgeon Theodor Billroth. Vincenz Czerny, another German surgeon, performed the first esophageal resection for cancer in a human in 1877. His patient lived for one year before dying from recurrence of the tumor. In 1913, American surgeon Franz Torek performed the first transthoracic excision of a mid-esophageal carcinoma. His patient was a 67-year-old woman with squamous cell carcinoma of the mid-esophagus. Torek tunneled the cervical esophagus of the patient along her anterior chest wall and formed a cutaneous esophagostomy, which was then connected by a rubber tube to a gastrostomy. The patient lived in good health for 13 years.(1) In Germany, the surgeon E. Heller performed the first esophagomyotomy, to treat achalasia, in 1913. In 1961, Rudolph Nissen, a Swiss surgeon, and later (ie, 1967) English surgeons David B. Skinner and Ronald H. R. Belsey used fundoplication (ie, a reduction in the size of the esophageal hiatus and suturing of the esophagus to the fundus) to create an intraabdominal esophageal valve mechanism to control gastroesophageal reflux.(2) In the ensuing years, many improvements have been made in surgical techniques, anesthesia delivery, diagnostic measures, and in preoperative and postoperative care of patients with esophageal disorders.

EPIDEMIOLOGICAL ASPECTS

Despite the progress in treatment of many esophageal disorders, esophageal cancer is the seventh leading cause of cancer deaths in the world.(3) The most significant risk factors for this malady in the United States are alcohol consumption and cigarette abuse. Associated risk factors for esophageal cancer are disorders of the esophagus such as

* hiatal hernia,

* esophageal stricture,

* gastroesophageal reflux, and

* severe esophagitis.(4)

Cancer of the esophagus is of epidemic proportions in some areas of the world (ie, northeastern Iran, the Transkei of South Africa, the Hunan province of China, and certain areas of Russia, India, the Middle East, and Singapore). In the Hunan province, the prevalence of esophageal carcinoma is 0.9% in people more than 30 years of age. The incidence in humans is matched in the poultry population in the same area. Epidemiological studies suggest that the etiology in both instances is the presence of large amounts of carcinogenic nitrosamines in the soil and contamination of foods by fungi and yeast that produce mutagens.

Drinking "burning hot" tea and chewing tobacco (with or without betel nut) are believed to cause esophageal damage that leads to cancer.(5) Decreased intake of vitamins A, C, E, [B.sub.12], folic acid, riboflavin, and the mineral zinc are also believed to be associated with esophageal cancer.(6) The neuromuscular esophageal disorder termed achalasia (ie, a Greek word meaning failure to relax) is a premalignant lesion that leads to carcinoma in 1% to 10% of people who have had the disease for 15 to 25 years.(7) In Brazil, Chagas' disease, which results from infestation with the parasite Trypanosoma cruzi, affects one of every eight Brazilians, and 5% of these individuals develop motor disorders of the esophagus known as infectious achalasia.(8) Achalasia has also developed after severe emotional and physical trauma and drastic weight reduction in markedly obese people. Because achalasia is incurable and treatment at best is purely palliative, it contributes greatly to morbidity.