12 Swallowing Difficulty and Pain John P. Sutyak Objectives 1. To distinguish between dysphagia and odynophagia. 2. To discuss the anatomy and physiology of the swallowing structures and mechanism, including the physiologic lower esophageal sphincter. 3. To discuss pertinent clinical history and physical examination findings as they relate to structural and functional pathology. 4. To develop a focused evaluation plan based on history and physical exam findings. 5. To describe various therapeutic options for patients with neurologic, neoplastic, reflex- mediated, and dysmotility-mediated disorders. Cases Case 1 A 58-year-old man presents to your office complaining of difficulty in swallowing. He has sustained a weight loss of 15 pounds over the past 3 months. Case 2 A 39-year-old woman presents to your office with burning chest pain, rapidly worsening over 3 years. Recent treatment with an H2 blocker has relieved her symptoms. Case 3 A 72-year-old woman presents to your office with difficulty in swal- lowing for decades. She describes a recent, worsening sensation of sub- sternal fullness. 200 12. Swallowing Difficulty and Pain 201 Introduction The swallowing mechanism is a complex interaction of pharyngeal and esophageal structures designed for the seemingly simple purpose of propelling food to the stomach and of allowing the expulsion of excess gas or potentially toxic food out of the stomach. Initial evaluation of a patient complaining of difficulty (dysphagia) or pain (odynophagia) with swallowing involves a thorough, focused history and a physical examination. Appropriate diagnostic tests then can be employed. The advent of esophageal motility and pH studies has permitted correla- tion of physiologic data to the anatomic information obtained through radiographic and endoscopic studies. Myriad primary and secondary processes may affect the swallowing mechanism. Some may be pathologic and the cause for the patient’s symptoms. Others may only confuse the diagnosis, having no relationship to the patient’s complaints. In evaluating swallowing difficulty and pain, it is extremely important to relate symptoms to diagnosis, as inappropri- ate therapy actually may worsen the patient’s symptoms or initiate new complications. Anatomic Considerations The esophagus is a muscular tube extending from the cricoid to the stomach. It is composed of a mucosal layer, a submucosa, and a double outer muscular layer (Fig. 12.1). No serosa is present on the esopha- gus, resulting in a structure that has less resistance to perforation, infiltration of malignant cells, and anastomotic breakdown follow- Ganglia of myentetric plexus [Auerbach] Ganglia of submucosal plexus (Meissner) Epithelium Submucosa Muscularis mucosa Lamina propria Muscularis externa Esophageal gland Longitudinal muscle layer Figure 12.1. Cross section of the esophagus showing the layers of the wall (Reprinted from Jamieson GG, ed. Surgery of the Esophagus. Edinburgh: Churchill Livingstone, 1988. Copyright © 1988 Elsevier Ltd. With permission from Elsevier.) 202 J.P. Sutyak ing surgery. Three layers compose the esophageal mucosa: a stratified, nonkeratinizing squamous epithelial lining; the lamina propria (a matrix of collagen and elastic fibers); and the muscularis mucosae. The squamous epithelium of the esophagus meets the junctional columnar epithelium of the gastric cardia in a sharp transition called the Z-line, typically located at or near the lower esophageal sphincter (Fig. 12.2). Although the upper third of esophageal muscle is skeletal and the distal portion is smooth, the entire esophagus functions as one coordi- nated structure. Contraction of the longitudinal muscle fibers of the esophageal body produces esophageal shortening. The inner circular muscle is arranged in incomplete rings, producing a helical pattern that, on contraction, produces a corkscrew-type propulsion. Muscle layers are of uniform thickness until the distal 3 to 4cm, where the inner circular layer thickens and divides into incomplete horizontal muscu- lar bands on the lesser gastric curve and oblique fibers that become the gastric sling fibers on the greater curve. Although no complete circu- lar band exists as an anatomic lower esophageal sphincter (LES), it is the area of rearranged distal circular fibers that corresponds to the high-pressure zone of the LES. In an adult, the cricopharyngeal muscle is located approximately 15cm from the incisors, and the gastroesophageal junction is located approximately 45cm from the incisors. The esophagus has abundant lymphatic drainage within a dense submucosal plexus. Because the lymphatic system is not segmental, lymph can travel a long distance in the plexus before traversing the muscle layer and entering regional lymph nodes. Tumor cells of the Figure 12.2. Anatomic relationships of the distal esophagus and phreno- esophageal ligament. (Reprinted from Gray SW, Skandalakis JE, McClusky DA. Atlas of Surgical Anatomy for General Surgeons. Baltimore: Williams & Wilkins, 1985, with permission.) 12. Swallowing Difficulty and Pain 203 upper esophagus can metastasize to superior gastric nodes, or a cancer of the lower esophagus can metastasize to superior mediastinal nodes. More commonly, the lymphatic drainage from the upper esophagus courses into the cervical and peritracheal lymph nodes, while that from the lower thoracic and abdominal esophagus drains into the retrocar- diac and celiac nodes. The esophagus has both sympathetic and parasympathetic innerva- tion. The sympathetic supply is through the cervical and thoracic sym- pathetic chains as well as through the splanchnic nerves derived from the celiac plexus and ganglia. Parasympathetic innervation of the pharynx and esophagus is primarily through the vagus nerve. The vagal trunks contribute to the anterior and posterior esophageal plexi. At the diaphragmatic hiatus, these plexi fuse to form the anterior and posterior vagus nerves. A rich intrinsic nervous supply called the myenteric plexus exists between the longitudinal and circular muscle layers (Auerbach’s plexus) and in the submucosa (Meissner’s plexus). Physiology of Swallowing Passage of food from mouth to stomach requires a well-coordinated series of neurologic and muscular events. The mechanism of swal- lowing is analogous to a mechanical system consisting of a piston pump (tongue) filling and pressurizing a cylinder (hypopharynx) con- nected to a three-valve (soft palate, epiglottis, and cricopharyngeus) system that propels material into a worm drive (esophagus) with a single distal valve (LES). Failure of the pump, valves, or worm drive leads to abnormalities in swallowing such as difficulty in propelling food from mouth to stomach or regurgitation of food into the oral pharynx, nasopharynx, or esophagus. The LES acts as the valve at the end of the esophageal worm drive and provides a pressure barrier between the esophagus and stomach. Although a precise anatomic LES does not exist, muscle fiber architec- ture at the esophagogastric junction explains some of the sphincter- like activity of the LES. The resting tone of the LES is approximately 20mmHg. With initiation of a swallow, LES pressure decreases, allow- ing the primary peristaltic wave to propel food into the stomach. A pharyngeal swallow that does not initiate peristaltic contraction also leads to LES relaxation, permitting gastric juice to reflux into the distal esophagus. The coordinated activity of the pharyngeal swallow and LES relaxation appears to be in part vagally mediated. The intrin- sic tone of the LES can be affected by diet and medications as well as by neural and hormonal mechanisms (Table 12.1). History and Physical Examination A precise medical history is essential to obtaining an accurate diag- nosis of swallowing difficulties. Does the patient suffer from difficulty in swallowing (dysphagia) alone, or is pain with swallowing (odynophagia) a primary or associated complaint? If pain is the 204 J.P. Sutyak primary complaint, elucidate its nature (squeezing, burning, pressure), aggravating factors (temperature and type of food, liquids and/or solids, medications, caffeine, alcohol, position, size or time of meals), relieving factors (medications, position, eructation, emesis), time course (lifelong, several years, slow progression, worsening, stable, episodic, constant), and associated factors (patient age, weight gain or loss, presence of a mass in the neck, preexisting disease processes, chronic cough, asthma, recurrent pneumonia, tobacco and alcohol use). When dysphagia is not associated with pain or with pain as a minor complaint, questioning should still follow the pattern above (nature, aggravating factors/relieving factors/time course/associated factors) and include questions focusing on disease progression (difficulty with solids at first, then difficulty with liquids, or difficulty with both solids and liquids). Appropriate identification and evaluation of esophageal abnor- malities rely on a thorough understanding of the patient’s symptoms and of how these symptoms relate to various disorders. Table 12.2 lists symptoms that may be attributable to esophageal disorders. Occa- sional symptoms are common and of no pathologic significance. However, frequent and persistent symptoms should prompt further investigation. A useful method is to determine how much the symp- toms have affected the patient’s lifestyle in terms of activity, types of food eaten, interruption of employment, and effects on family life. A precise relationship of symptoms to diagnosis is essential in order to avoid inappropriate