Esophagoscopy and Hypopharyngoscopy

Introduction

Disorders of the esophagus present a challenge to the otolaryngologist owing to the broad variety of pathology and oftentimes nonspecific nature of patient complaints. Using a mirror, Bozzini in 1809 was credited with the first attempts to evaluate the esophagus. Initially described in 1868 by Kussmaul, the straight esophagoscope underwent multiple refinements until the early 1900s when Chevalier Jackson introduced the technique and instrumentation of modern rigid esophagoscopy. After fiberoptic illumination was pioneered for this technique in the 1930s, flexible endoscopy was introduced in the 1960s and eventually led to the creation of the transnasal endoscope in the 1990s. The evolution of the technique and instrumentation reflects the challenges associated with evaluating the esophagus. The advent of flexible and rigid endoscopy has afforded the modern day practitioner several methods for conducting a thorough patient-specific assessment.

The diagnosis and management of esophageal disorders requires a thorough understanding of esophageal anatomy. The esophagus is a muscular conduit extending from the inferior portion of the pharynx to the superior portion of the stomach. At the approximate level of the sixth cervical vertebra, the esophagus begins at the pharyngoesophageal junction in the hypopharynx and descends to the level of the 11th thoracic vertebra, where it enters the cardia portion of the stomach. Shortly after its takeoff, the esophagus has a gentle leftward curvature until the level of the fifth thoracic vertebra, at which point it resumes its midline course. A second leftward curve of the esophagus can be appreciated as it crosses the descending aorta prior to entering the esophageal hiatus of the diaphragm; however, some sources have also noted the thoracic esophagus to have a right curvature due to the main stem bronchus.

The esophagus measures 22 to 25 cm in total length and can be divided into cervical, thoracic, and abdominal portions. The cervical esophagus begins at the cricopharyngeus and extends to the suprasternal notch, the thoracic portion from the suprasternal notch to the diaphragm, and the abdominal portion from the diaphragm to the stomach. Throughout its length, there are three constrictions of the conduit that the endoscopist should be familiar with. Approximately 16 cm from the upper incisors, the first and narrowest constriction occurs at the cricopharyngeal sphincter. At 23 to 27 cm from the upper incisors, the second constriction occurs at the level of the left main stem bronchus. The final constriction occurs at the gastroesophageal sphincter, 38 to 40 cm from the upper incisor teeth.

Histologically, the esophagus is composed of four circular layers: mucosa, submucosa, muscular layer, and adventitia. The esophagus lacks a serosa, a unique characteristic that differentiates it from the rest of the gastrointestinal tract.

Key Operative Learning Points

• 1.

  Flexible and rigid esophagoscopy allow for visualization and instrumentation of the esophagus under specific situations. Understanding both techniques allows the practitioner to perform a safe and thorough evaluation depending on the patient’s general medical condition, ability to tolerate the procedure, and suspected diagnosis.

• 2.

  Understanding esophageal anatomy allows the endoscopist to safely perform esophagoscopy while minimizing the potential for complications such as perforation.

Preoperative Period

Operative Period

The general condition of the patient, purpose of intervention, and patient compliance are three factors that determine whether patients should undergo rigid esophagoscopy or flexible esophagoscopy. Flexible esophagoscopy can be performed either transorally or transnasally. Flexible esophagoscopy allows for visualization of the gastroesophageal junction and improved instrumentation in patients with limited range of motion at the neck or obstructing osteophytes. Transoral esophagoscopy is typically performed under sedation and topical anesthesia, whereas transnasal esophagoscopy is performed with topical anesthesia only. Transnasal esophagoscopy is well suited for the office setting, is of minimal risk, and allows for patients to return home without need for observation. This procedure can be performed with relatively little patient discomfort and is associated with mostly minor complications, such as epistaxis. It is imperative that prior to any procedure, a full discussion of the risks and benefits be discussed with patients in a manner suited to their level of understanding. Overall, flexible esophagoscopy is a viable option for patients that cannot tolerate general anesthesia; however, it is important to note that it has limitations and should be reserved for specific situations. According to recent studies, transnasal esophagoscopy can be helpful in changing the course of management in male patients, obese patients, and especially those patients with a history of dysphagia associated with head and neck cancer.

Rigid esophagoscopy is more advantageous in evaluating the hypopharynx, cricopharyngeal sphincter, and cervical esophagus. Oftentimes, redundant mucosal folds can hide pathology which can be readily missed with flexible esophagoscopy. Rigid instrumentation also confers the advantage of allowing larger suction cannulas and larger caliber instruments to be used for retrieval of foreign bodies.