Kursk State Medical University



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THE KURSK STATE MEDICAL UNIVERSITY

Department of surgical diseases № 1

Disorders of Esophageal Motility

Information for self-training of English-speaking students

The chair of surgical diseases N 1 (Chair-head - prof. S.V.Ivanov)

By ass. professor M.V. Yakovleva

KURSK-2010

HISTORY

Traumatic lesions of the cervical esophagus were identified in ancient times, and survival was observed when a cervical esophageal fistula formed that allowed the wound to heal gradually by secondary intention. Benign as well as neoplastic strictures of the esophagus were treated by dilatation at this time. Anatomic dissections performed during the Renaissance provided a systematic way to study the consequences of esophageal injury and stricture, so by the middle of the 18th century, techniques had been developed to remove foreign bodies and to dilate strictures of the cervical esophagus. By the middle of the 19th century, strictures were being approached by internal as well as external myotomies with some success but with a prohibitive leak and death rate. Major advances in esophageal surgery awaited the imaging potential of radiography and endoscopy, which occurred in the early part of the 20th century. Successful transthoracic operations on the thoracic esophagus were enhanced by the development of endotracheal anesthesia, antibiotics, and blood transfusions during World War II. More recently, video-assisted thoracoscopic techniques gained popularity.

ANATOMY

Esophagus

The esophagus is a hollow tube of muscle approximately 25 to 30 cm long, beginning at C6 (cricoid cartilage level) and ending at T11, that penetrates the diaphragm and joins the cardia of the stomach . The esophagus lies anterior to the vertebral column and longus colli muscles and posterior to the trachea. It is divided into four segments: pharyngoesophageal, cervical, thoracic, and abdominal. The length between the laryngopharynx and cervical esophagus is the pharyngoesophageal segment. The pharyngeal musculature includes the superior, middle, and inferior constrictors, as well as the stylopharyngeus muscles. The inferior pharyngeal constrictor (thyropharyngeus muscle) passes obliquely and superiorly from its origin on the thyroid cartilage to its posterior insertion in the median raphe. The esophageal introitus (cricopharyngeus muscle or upper esophageal sphincter) is the most inferior portion of the inferior pharyngeal constrictor and is identifiable by the transverse direction of its fibers. The transition between the oblique fibers of the thyropharyngeus muscle and the transverse fibers of the cricopharyngeus muscle creates a point of potential weakness in the pharyngoesophageal segment (site of origin of a pharyngoesophageal diverticulum and a common site of perforation during esophagoscopy). The cricopharyngeal sphincter is unique to the gastrointestinal tract because it does not consist of a circular ring of muscle, but rather it is a bow of muscle connecting the two lateral borders of the cricoid cartilage. The cricopharyngeus muscle fibers blend into the longitudinal and circular muscle of the cervical esophagus, a 5- to 6-cm segment that extends to the beginning of the first thoracic vertebra.

Although the cervical esophagus is a midline structure positioned posterior to the trachea, it tends to course to the left of the trachea and is therefore more easily approached surgically through a left-sided neck incision. The cervical esophagus lies just anterior to the prevertebral fascia and can normally be separated from its loose fibrous posterior attachments by blunt finger dissection of the prevertebral space. On each side of the cervical esophagus lie the carotid sheath and the thyroid gland, with the recurrent laryngeal nerves passing bilaterally in the groove between the esophagus and the trachea.

The thoracic esophagus passes into the posterior mediastinum, passes behind the aortic arch and great vessels, and curves to the left of the trachea behind the left main stem bronchus. It then deviates to the right for several centimeters in the subcarinal area and returns to the left of midline and anterior to the thoracic aorta as it proceeds behind the pericardium to the level of the seventh thoracic vertebra. At this point, the esophagus deviates farther to the left and anteriorly, and it enters the esophageal diaphragmatic hiatus at the level of the eleventh thoracic vertebra. The lateral boundaries of the thoracic esophagus are the right and left parietal pleurae.

The diaphragmatic esophageal hiatus is a sling of muscle fibers that arise from the right crus in approximately 45% of patients; however, both the left and the right crura may contribute to the hiatus. The abdominal esophagus (1 to 2 cm long) extends from the esophageal hiatus to the cardia of the stomach to form the esophagogastric junction. The location of the esophagogastric junction has been defined in different ways: (1) the junction of esophageal squamous and gastric columnar epithelium; (2) the point at which the tubular esophagus joins the gastric pouch; and (3) the junction of the esophageal circular muscle layer with the oblique sling fibers of the stomach (loop of Willis or collar of Helvetius). Clinically, the squamocolumnar epithelial junction (ora serrata or Z line), as identified endoscopically, is the most practical definition of the gastroesophageal junction, provided the patient does not have a columnar-lined lower esophagus. The phrenoesophageal membrane is a fibroelastic sheet of tissue that extends circumferentially from the muscular margins of the diaphragmatic hiatus to the esophagus. The majority of the phrenoesophageal membrane arises from the endoabdominal fascia and inserts into the esophagus for 2 to 3 cm above the hiatus and 3 to 5 cm above the mucosal junction. Fibrous strands from the upper surface of the diaphragm (fascia of Laimer) contribute to the phrenoesophageal membrane. The functional significance of the phrenoesophageal membrane is unknown; however, this tissue lacks sufficient strength to reliably anchor the esophagogastric junction in the abdomen during an antireflux operation.

The esophagus has three distinct areas of anatomic narrowing. The cervical constriction occurs at the level of the cricopharyngeus sphincter, the narrowest point of the gastrointestinal tract (14 mm in diameter). The bronchoaortic constriction (15 to 17 mm) is located at the level of the fourth thoracic vertebra behind the tracheal bifurcation where the left main stem bronchus and the aortic arch cross the esophagus. The diaphragmatic constriction (16 to 19 mm) occurs where the esophagus traverses the diaphragm. Between these areas of constriction, the esophagus has a wider caliber, termed the superior and inferior dilatations. The normal adult thoracic esophagus has a maximum diameter of approximately 2.5 cm on barium swallow examination.

The esophagus is a mucosal-lined muscular tube that lacks a serosa and is surrounded by a layer of loose fibroalveolar adventitia. Beneath the adventitia is a layer of longitudinal muscle overlying an inner layer of circular muscle. Between the two muscular layers is a thin intramuscular septum of connective tissue that contains fine blood vessels and ganglion cells (Auerbach plexus). Both the longitudinal and the circular muscle layers of the upper third of the esophagus are striated, whereas the layers of the lower two thirds are smooth. The fatty and relatively thick submucosa permits considerable mobility of the esophageal mucosa. The submucosa contains the mucus glands, blood vessels, the Meissner neural plexus, and an extensive lymphatic network. The esophageal mucosa consists of squamous epithelium except for the distal 1 to 2 cm, which is junctional columnar epithelium. Occasionally, ectopic gastric mucosa may be found throughout the length of the esophagus.

The esophagus is nourished by numerous segmental arteries. The cervical esophagus receives blood from the superior thyroid artery as well as the inferior thyroid artery of the thyrocervical trunk, with both sides communicating through collateral vessels. The major blood supply of the thoracic esophagus is from four to six aortic esophageal arteries, supplemented by collateral vessels from the inferior thyroid, intercostal and bronchial, inferior phrenic, and left gastric arteries. The aortic esophageal arteries terminate in fine capillary networks before they actually penetrate the esophageal muscle layer. After penetrating and supplying the muscle layers of the esophagus, the esophageal capillary network runs longitudinally in the submucosa. The extensive venous drainage of the esophagus includes the hypopharyngeal, azygous, hemiazygous, intercostal, and gastric veins.

The esophagus has both sympathetic and parasympathetic innervation. In the neck, the superior laryngeal nerves arise from the vagus nerve and divide into the external and internal laryngeal branches. The external laryngeal nerve innervates the cricothyroid muscle and also, in part, the inferior pharyngeal constrictor. The internal laryngeal nerve is the sensory nerve of the pharyngeal surface of the larynx and the base of the tongue. The recurrent laryngeal branches of the vagus nerve provide parasympathetic innervation to the cervical esophagus as well as innervation to the upper esophageal sphincter. Injury to the recurrent laryngeal nerve may result in hoarseness as well as upper esophageal sphincter dysfunction, with secondary aspiration on swallowing. In the thorax, the vagus nerve sends fibers to the striated muscle as well as parasympathetic preganglionic fibers to the smooth muscle. Sympathetic innervation consists of fibers to the cervical esophagus from the superior and inferior cervical sympathetic ganglia, to the thoracic esophagus from the upper thoracic and splanchnic nerves, and to the intra-abdominal esophagus from the celiac ganglion. The Meissner and Auerbach plexuses provide an intrinsic autonomic nervous system within the esophageal wall. The Meissner plexus of nerves is located in the submucosa, whereas the Auerbach plexus is in the connective tissue between the circular and longitudinal muscle layers. The two major branches of the vagus nerves lie along either side of the thoracic esophagus and form two large nerve plexuses supplying the esophagus and the lungs. The esophageal vagus plexuses coalesce and become single trunks, 2 to 6 cm above the esophageal hiatus. The left branch of the vagus nerve lies anterior to the esophagus, and the right branch is posterior, at the diaphragmatic hiatus.

The esophagus has an extensive lymphatic drainage that consists of two lymphatic plexuses, one arising in the mucosa and the other in the muscular layer. Mucosal lymphatic capillaries may pierce the muscular layer and drain to regional lymph nodes. These lymphatic capillaries may run longitudinally in the esophageal wall before they exit through muscle into adjacent lymph nodes. The flow of lymphatics of the upper two thirds of the esophagus tends to be upward, whereas the distal third tends to be downward; however, all lymphatics intercommunicate. Therefore, esophageal carcinomas may metastasize to internal jugular nodes in the neck, paratracheal nodes in the superior mediastinum, subcarinal nodes in the middle chest, paraesophageal nodes in the lower mediastinum, and inferior pulmonary ligament, perigastric, and left gastric artery lymph nodes.

Thoracic Duct

The proximity of the thoracic duct to the esophagus makes it vulnerable to injury during esophageal surgery. The thoracic duct forms at the confluence of the cisterna chyli at a level between the twelfth thoracic and second lumbar vertebrae and to the right side of the abdominal aorta. The duct enters the posterior mediastinum through the aortic hiatus at the level of T10 to T12 and continues cephalad on the anterior surface of the vertebral column between the aorta and the azygous vein and behind the esophagus. At T4 to T5, the duct crosses to the left of the spine, passes under the aortic arch, and continues along the left side of the esophagus, to ascend into the neck posterior to the left subclavian artery. In the neck, the duct lies anterior to the vertebral artery and vein, thyrocervical trunk, and phrenic nerve, and it enters the venous system at the junction of the left subclavian and left internal jugular veins. Operations on the thoracic esophagus, particularly after previous surgery or radiation therapy with consequent periesophageal fibrosis, may result in chylothorax from thoracic duct injury.

PHYSIOLOGY

The basic function of the esophagus is to transport swallowed material from the pharynx into the stomach. Secondarily, retrograde flow of gastric contents into the esophagus is prevented by the lower esophageal sphincter (LES). The entry of air into the esophagus with each inspiration is prevented by the upper esophageal sphincter (UES), which normally remains closed as a result of tonic contraction of the cricopharyngeus muscle. Еsophageal motility studies have become a basic diagnostic tool in evaluating disorders of esophageal motor function such as dysphagia, chest pain of undetermined origin, and gastroesophageal reflux.

Three types of contractions are seen in the esophageal body. Primary peristalsis is progressive and is triggered by voluntary swallowing. Secondary peristalsis is also progressive, but it is generated by distention or irritation, not by voluntary swallowing. Tertiary contractions are nonprogressive (simultaneous) contractions that may occur either after voluntary swallowing or spontaneously between swallows. As the swallowed bolus enters the esophagus from the pharynx, a primary peristaltic wave is activated that transverses the esophageal body at a speed of 2 to 5 cm per second and propels the swallowed material from the pharynx into the stomach in 4 to 8 seconds in an orderly, progressive manner. Normally, a progressive peristaltic contraction (primary wave) follows 97% of all wet swallows. If the entire swallowed bolus of food does not empty from the esophagus into the stomach, secondary peristaltic waves are initiated. These contractions, like the primary waves, are progressive and sequential, but they begin in the smooth muscle segment of the esophagus (near the level of the aortic arch) and continue until retained intraesophageal contents are emptied into the stomach. Thus, unlike the primary wave, the secondary contraction is not initiated by a voluntary swallow, but rather it is initiated by local distention of the esophagus. Tertiary contractions are simultaneous, nonprogressive, nonperistaltic, monophasic, or multiphasic waves that can occur throughout the esophagus and represent uncoordinated contractions of the smooth muscle that are responsible for the classic "corkscrew" appearance of esophageal spasm on barium swallow examination. Increased resting pressures within the body of the esophagus and abnormal motor function are seen in patients with either mechanical or functional obstruction.

The term lower esophageal sphincter implies the presence of an anatomic sphincter such as the pylorus. Although no such anatomic LES has been demonstrated, manometry has defined an elevated distal esophageal resting pressure that is 3 to 5 cm in length, which serves as the barrier against abnormal regurgitation of gastric contents into the esophagus and represents a functional sphincter . Thus, the LES is more accurately referred to as the LES mechanism or the distal esophageal high-pressure zone (HPZ). The factors responsible for maintaining competence of the LES are poorly understood, but the presence of an intra-abdominal segment of distal esophagus, under the influence of positive intra-abdominal pressure, seems important to the success of most antireflux operations.

Normal resting pressure within the HPZ ranges from 10 to 20 mm Hg, but no absolute HPZ per se indicates either competence or incompetence of the LES mechanism. Patients with no gastroesophageal reflux may have an extremely low HPZ amplitude on manometric recordings, whereas others with massive reflux may have seemingly high distal pressures. This inconsistency is a reflection of both HPZ variation from individual body habitus.

ESOPHAGOSCOPY

Esophagoscopy, which permits direct evaluation of the interior of the esophagus, is among the most vital diagnostic tools in the assessment of the patient with esophageal symptoms from any cause. With technical advances in flexible fiberoptic esophagogastroscopy, the number of these procedures being performed has increased greatly. However, as esophagoscopy has become a more commonly performed operation, a rather cavalier attitude toward this procedure has emerged. It should be kept in mind that esophagoscopy, particularly with dilatation of a stricture, is one of the most dangerous operations performed, the horrendous complications of a perforation being all too familiar to those called on to treat patients with esophageal disruption. Rigid adherence to basic principles of esophagoscopy is consistently rewarded by fewer complications.

INDICATIONS AND CONTRAINDICATIONS

Esophagoscopy is indicated in a variety of diagnostic and therapeutic situations.5 Diagnostically, features of dysphagia, odynophagia, reflux that persists or recurs despite adequate therapy, occult blood loss, hematemesis, and atypical chest pain most often warrant esophagoscopy. Esophagoscopy is also useful in assessing established esophageal pathology—esophagitis, Barrett's mucosa, neuromotor dysfunction, caustic injury, or tumors. Definition and confirmation of ra-diologic abnormalities—stricture, hiatal hernia, suspected esophagitis, diverticula, varices, and extrinsic compression— are common indications for esophagoscopy. Finally, esophagoscopy is of great diagnostic value in the assessment of postoperative problems—anastomotic stricture, tumor recurrence, bleeding, dysphagia, or recurrent gastroesophageal reflux. From a therapeutic standpoint, dilation and biopsy of strictures, removal of foreign bodies, placement of endo-luminal prostheses, sclerotherapy, endoscopic myotomy (Dohlman's procedure), and laser photocoagulation for bleeding or tumor debulking are the usual indications for esophagoscopy. Esophagoscopy is not indicated to assess reflux symptoms that respond to medical management, an uncomplicated sliding hiatal hernia, or a previous demonstrated benign stricture (not associated with Barrett's mucosa). It cannot be overemphasized that safe esophagoscopy demands a well-trained endoscopist, properly functioning equipment, and resuscitative support in the event that a cardio-respiratory complication occurs. Esophagoscopy should not be performed in a struggling, uncooperative, agitated patient. Additional relative contraindications include a recent myo-cardial infarction, severe cervical spine deformities, and a large thoracic aortic aneurysm.

GENERAL CONSIDERATIONS

Safe esophagoscopy requires familiarity with normal esophageal anatomy, particularly the three areas of constriction and the course of the esophagus through the thorax. As a general rule, and certainly in the case of rigid esophagoscopy, elective esophagoscopy should be preceded by a barium esophagogram, which ideally should be displayed in view of the endoscopist during the procedure. Knowledge of existing esophageal pathology that is readily visible on a barium esophagogram is extremely important, so that the endoscopist does not begin the journey down the esophagus without a road map. Perforating a pharyngoesophageal diverticulum, for example, cannot be condoned just because the surgeon was unaware of its presence before esophagoscopy.

Before performing esophagoscopy, it is helpful to relate pathology seen on the barium swallow examination to certain anatomic landmarks and then to extrapolate from lid assessment the approximate level within the esophagus at which the abnormality should be seen. The cricopharyngeus sphincter, for example, is located on the barium esophagogram at the level of the seventh cervical or first thoracic vertebral bodies, or approximately 15 cm. from the upper incisor teeth at esophagoscopy. Topographically, the angle of Louis (the sternomanubrial junction) on the anterior chest wall aligns with the tracheal bifurcation, which can usual; be seen in most barium esophagograms at about the level of the fourth thoracic vertebra, and corresponds to a point 25 cm. from the incisors on esophagoscopy. The esophagogastric junction is typically seen endoscopically 40 cm. from the upper incisors approximately at the level of the eleventh or twelfth thoracic vertebrae.

Until refinements and wide availability of the flexible esophagogastroscopes in the 1970s, rigid esophagoscopy was most commonly used for endoscopic assessment of esophagus. Its disadvantages included the frequent need for general anesthesia and the danger of introduction of the instrument in a patient with cervical spine disease. The greater comfort and ease of flexible endoscopy have now made this the procedure of choice in most patients requiring esophagoscopy. However, there are definite situations in which rigid esophagoscopy has distinct advantages. The rigid esophagoscope is best for evaluating lesions at or just below the cricopharyngeal sphincter, removal of foreign bodies, dilatation of certain high-grade stenoses, obtaining larger and more adequate biopsy specimens, and significant esophageal bleeding.

COMPLICATIONS OF ESOPHAGOSCOPY

Esophagoscopy can cause either relatively minor complications (laceration of the lips or tongue, fracture or dislodgment of teeth, pharyngeal lacerations) or catastrophic events (massive tracheobronchial aspiration, esophageal perforation). Fortunately, the complication rate from esophagoscopy is relatively low. Most minor complications are a result of poor technique and failure to adequately protect the gums, lips, and teeth during the procedure. By far, the leading and most serious complication of esophagoscopy, with or without dilation of a stricture, is perforation, which occurs in 1 to 2 per cent of patients, even in the hands of the most experienced endoscopist. It is a basic surgical principle that pain or fever after esophageal instrumentation represents an esophageal perforation until proven otherwise and is an indication for an immediate esophagogram.14 Because the mortality and morbidity of an esophageal perforation are directly related to the time interval between the occurrence of the injury and its diagnosis and repair or drainage, an extremely aggressive position toward diagnosing a perforation after endoscopy must be adopted. A contrast study with both a water-soluble agent (Gastrografin) as well as dilute barium, if no perforation is seen, should be obtained, because a perforation may be overlooked on roentgenographic evaluation when only Gastrografin is used . The treatment of esophageal perforation is discussed elsewhere in this chapter.

Disorders of Esophageal Motility

Disorders of esophageal motility are functional disorders, conditions that interfere with the normal act of swallowing or produce dysphagia without any associated intraluminal organic obstruction or extrinsic compression. As a general rule, barium swallow examination, esophagoscopy, and esophageal function tests, including manometry and intraesophageal pH reflux testing, constitute the basic evaluation of the patient with a suspected disorder of esophageal motility.

Upper Esophageal Sphincter Dysfunction

The terms oropharyngeal dysphagia and cricopharyngeal dysfunction perhaps best describe the symptom complex that occurs when patients have difficulty in swallowing liquid or solid food from the oropharynx into the upper esophagus. The many causes of this difficulty include abnormalities of the central and peripheral nervous system, metabolic and inflammatory myopathy, gastroesophageal reflux, and complications of neck or thoracic surgery. Anatomically related causes of upper esophageal dysphagia, such as carcinoma, caustic stricture, cervical vertebral bone spurs, thyromegaly, and trauma, should always be excluded. A purely psychological cause of a complaint of cervical dysphagia, globus hystericus, is a diagnosis of exclusion made only after ruling out primary esophageal disease.

Despite the variety of neurogenic and myogenic conditions involving the pharyngoesophageal junction, the resulting oropharyngeal dysphagia has a remarkably constant clinical presentation. The dysphagia is localized between the thyroid cartilage and the suprasternal notch as a lump in the throat or as occasional pain radiating to the jaw and ears. Expectoration of excessive saliva is common in patients who are unable to swallow the 1 to 1.5 liters of saliva produced each day. Hoarseness often occurs with cricopharyngeal dysfunction. Weight loss secondary to impaired caloric intake completes the diagnostic symptom complex of cricopharyngeal dysfunction. Symptoms of gastroesophageal reflux occur in 30 to 90% of patients with cricopharyngeal dysfunction, and whether refluxed gastric acid is actually causing local irritation of the UES in these patients or whether distal esophageal reflux is triggering incoordination of the pharyngoesophageal junction is unclear.

DIAGNOSIS

Studies to evaluate cricopharyngeal dysfunction include barium esophagogram, manometry, and acid reflux testing. The barium esophagogram may be normal, particularly in patients with intermittent symptoms, or it may demonstrate a spectrum of hypertonicity of the UES, a posterior cricopharyngeal bar, or a pharyngoesophageal (Zenkers) diverticulum. A complete esophagogram should rule out other significant esophageal disease, particularly a hiatal hernia with gastroesophageal reflux or a distal tumor, which may produce symptoms referred to the cervical esophagus. Esophagoscopy may rule out neoplasm and reflux esophagitis, both of which can result in cervical dysphagia. Esophageal function studies (manometry and acid reflux testing) should also be performed. Use of the Dent sleeve has increased our ability to document the complex motor events that occur with swallowing and their derangement in patients with UES dysfunction. Incoordination of the temporal relationship between pharyngeal contraction and cricopharyngeal relaxation has been reported to be responsible for the development of pharyngoesophageal diverticula. Abnormalities of thoracic esophageal peristalsis may be found in one third of patients with cricopharyngeal dysfunction, a finding suggesting that cervical esophageal complaints are a manifestation of more generalized disordered esophageal motor function. The demonstration of gastroesophageal reflux allows appropriate postoperative positioning and reflux precautions.

TREATMENT

In view of the multiple causes of this condition, the treatment of cricopharyngeal motor dysfunction must be individualized. Patients with severe cervical dysphagia but no reflux symptoms may be treated successfully with a cervical esophagomyotomy. Patients with an incompetent LES but minimal symptoms may respond to medical antireflux therapy without the need for an antireflux operation. Finally, surgical treatment of severe or intractable gastroesophageal reflux may eliminate secondary cervical complaints. Intermittent outpatient esophageal bougienage to 54 to 56 French may produce dramatic temporary relief of incapacitating cervical dysphagia in patients with polymyositis, Parkinson's disease, or the residua of a midbrain (basilar artery) cerebrovascular accident. In the presence of persistent cervical dysphagia or aspiration and a radiographically or manometrically documented abnormal UES, a cervical esophagomyotomy is a low-risk operation with high benefit.

A cervical esophagomyotomy for cricopharyngeal dysfunction (in the absence of a Zenker diverticulum) is performed through a 5- to 8-cm oblique left-sided cervical incision centered at the level of the cricoid cartilage and paralleling the anterior border of the sternocleidomastoid muscle . The sternocleidomastoid muscle and carotid sheath and its contents are retracted laterally while the trachea is retracted medially (one should avoid placement of retractors on the tracheoesophageal groove with subsequent injury to the recurrent laryngeal nerve). The dissection proceeds posteriorly through the cervical fascial layers to the prevertebral fascia to mobilize the esophagus. The esophagus is not encircled.

With a 40-French bougie in the esophagus, the cervical esophagomyotomy is performed on the posterolateral esophageal wall. The incision (7 to 10 cm long) extends from the level of the tip of the superior cornu of the thyroid cartilage inferiorly to 1 to 2 cm behind the clavicle. This "extended" cervical esophagomyotomy is recommended to ensure division of all uncoordinated UES muscle fibers. A cervical esophagomyotomy is successful in relieving cervical dysphagia from cricopharyngeal motor dysfunction in 65 to 85% of patients undergoing the operation.

Motor Disorders of the Body of the Esophagus

The esophageal motor disorders are best viewed as a continuum, with hypomotility ( achalasia) at one extreme and hypermotility ( diffuse esophageal spasm [DES]) at the other. Between these extremes are conditions such as vigorous achalasia, which has elements of both achalasia and DES, as well as a variety of less clearly characterized examples of neuromotor dysfunction. Primary motor disturbances often present with mixed components and symptoms ranging from the severe crushing retrosternal pain of esophageal spasm (often mimicking a myocardial infarction) to the heavy fullness of retained food from achalasia.

Nonspecific neuromotor esophageal dysfunction, manifested by progressive peristalsis and simultaneous, weak-to-absent esophageal contractions after swallowing, is seen in numerous conditions, such as peripheral neuropathy (diabetes, alcoholism), collagen vascular diseases (scleroderma, dermatomyositis), myasthenia gravis, multiple sclerosis, and amyotrophic lateral sclerosis. In none of these conditions is an absolutely diagnostic esophageal motor disturbance present, but rather, these patients have an alteration of normal sequential peristaltic contractions with swallowing. In the presence of distal obstruction from either a tumor or a benign stricture, tertiary esophageal contractions may be seen in the body of the esophagus, both radiographically and with motility studies.

Esophageal motiliti stadies are only one facet of the total evaluation, and neuromotor disorders of the esophagus should be interpreted in the light of the particular clinical situation, as well as the barium swallow and endoscopic findings.

ACHALASIA

The origin of achalasia is unknown, but the characteristic clinical, radiographic, and manometric findings have resulted from various situations, including severe emotional stress, major physical trauma, drastic weight reduction, and Chagas' disease in South America. Chagas' disease, a parasitic infection by the leishmanial forms of Trypanosoma cruzi, is characterized by destruction of the smooth muscle ganglion cells of the Auerbach myenteric plexus, with resulting motor dysfunction and progressive dilation not only of the esophagus but also of the colon, ureters, and other viscera. In achalasia, the parasympathetic ganglion cells within the myenteric plexus, between the longitudinal and circular muscle layers of the esophagus, are markedly reduced in number. At autopsy, a decrease in the dorsal motor nucleus of the vagus has been found. Likewise, injury to the esophageal myenteric plexus by cold, heat, chemicals, or excision also leads to the characteristic manometric signs of the disease.

The term achalasia is of Greek derivation and literally means "failure or lack of relaxation." The name achalasia focuses on the LES, but the condition involves the entire esophageal body. Achalasia is usually a disease of middle age, with equal incidence for either sex. The classic triad of presenting symptoms includes dysphagia, regurgitation, and weight loss. In the early stages of achalasia, the patient notes a sticking sensation, usually at the level of the xiphoid, after ingestion of liquids, especially cold liquids, and later after ingestion of solids. Patients with achalasia eat slowly, use large volumes of water to wash food into the stomach, and may twist the upper torso, to elevate the chin and extend the neck, or they walk about the room in an effort to force down food. As more water is swallowed, the weight of the fluid column in the esophagus increases, along with the sensation of retrosternal fullness, until the LES is forced open, with sudden relief as the esophagus empties. Dysphagia progresses slowly and is well tolerated for many years. As a consequence, patients with achalasia often do not seek medical attention until progressive dysphagia interferes with their lifestyle. Regurgitation of undigested food is common as the disease progresses, and aspiration becomes life-threatening. Effortless regurgitation after eating, particularly on bending forward or reclining, is usually not associated with the sour taste of undigested food experienced in patients with acid regurgitation from gastroesophageal reflux.

As the esophagus dilates, regurgitation of foul-smelling, stagnant intraesophageal contents occurs. Achalasia often results in recurrent respiratory symptoms related to aspiration, which may cause pneumonia, lung abscess, bronchiectasis, hemoptysis, or bronchospasm. Marked distention of the dilated esophagus may produce dyspnea from compression of the main stem bronchi and hilum. Weight loss is common and may be significant enough to suggest malignancy.

Bleeding in achalasia is rare, and although it may be associated with retention esophagitis, it is generally an ominous sign indicative of carcinoma.

Achalasia is a premalignant esophageal lesion, with carcinoma developing as a late complication in 1 to 10% of patients who have this condition for an average of 15 to 25 years. Long-standing mucosal irritation from retention esophagitis appears to induce the metaplasia. Esophageal carcinoma in achalasia tends to arise in the middle third of the esophagus, below the air-fluid level, where the mucosal irritation is most pronounced.

This tumors, usually squamous cell histologically, generally grow to a large size, unnoticed by the patient with a dilated esophagus and chronic dysphagia and hopelessly incurable.

DIAGNOSIS

The radiographic appearance of achalasia varies with progression of the disease. The characteristic appearance on a standard chest x-ray is a double mediastinal stripe throughout the length of the chest and a retrocardiac air-fluid level in a patient with typical symptoms. The barium esophagogram shows mild dilatation in the early stages and massive dilatation, tortuosity, and a sigmoid shape in the later stages. Retained intraesophageal food contents are typically seen. The roentgenographic hallmark of achalasia on barium swallow examination is the distal bird-beak taper of the esophagogastric junction .

The manometric criteria of achalasia are failure of the LES to relax reflexively with swallowing and lack of progressive peristalsis throughout the length of the esophagus. In the early stages of achalasia, contractions after swallowing may be of normal amplitude, but they are synchronous and simultaneous. Later, contractions are either totally absent or weak. The distal esophageal HPZ pressure is generally normal or elevated, but the marked hypertonicity of DES is not seen. Administration of a mild vagomimetic agent (i.e., bethanechol [Urecholine]) produces marked elevation of intraesophageal pressure and increased amplitude and frequency of simultaneous esophageal contractions that correspond with the patient's complaint of chest pain. This response does not occur in scleroderma, but it is common both in DES and achalasia. However, the patient with intermittent DES, unlike someone with achalasia, usually has some degree of progressive peristalsis on standard manometric evaluation, and the LES shows reflex relaxation with swallowing.

In achalasia, esophagoscopy is indicated to evaluate the severity of esophagitis, the possibility of associated carcinoma, a distal esophageal stricture from reflux esophagitis, or a tumor of the cardia mimicking achalasia ( pseudoachalasia). Retention esophagitis in advanced achalasia is different endoscopically from reflux esophagitis. With chronic esophagitis due to reflux, thedistal esophagus often appears whitish and fibrotic with superficial mucosal ulceration. When the patient has prolonged retention esophagitis from achalasia, the irritating effects of putrefying food on the esophageal mucosa may induce severe edema, with reddish purple discoloration and marked friability. When one performs esophagoscopy in the evaluation of achalasia, the presence of retained fluid and food in the dilated esophagus, even after an overnight fast, may complicate the procedure, and additional efforts, such as cricoid pressure to protect the airway is indicated.

Secondary achalasia or pseudoachalasia, caused by a tumor at or near the gastroesophageal junction, is also best detected by endoscopy and biopsy. The precise imaging of endoscopic ultrasound can be used when endoscopic examination alone fails to confirm the diagnosis of secondary or primary achalasia. Endoscopic ultrasound may identify subepithelial tumor infiltration in secondary achalasia when results of biopsies of the cardia or gastroesophageal junction are negative. Furthermore, high-frequency ultrasound probes (20 MHz) allow more precise imaging of the various muscle layers that make up the muscularis propria and allow identification of patients with primary achalasia. The EUS can then be used to direct injection of botulinum toxin as therapy for achalasia. The high-frequency probes also can assess the response of the esophageal wall to therapy (pneumatic balloon versus botulinum toxin injection).

TREATMENT

Because the derangement in esophageal motor function does not return to normal, the treatment of achalasia is purely palliative. Both nonsurgical and surgical treatments of achalasia are directed toward relieving the obstruction caused by the nonrelaxing LES. In the early stages of the disease, before the esophagus dilates, use of sublingual nitroglycerin before or during meals, long-acting nitrates, and calcium-channel blocking agents may improve swallowing. Passage of mercury-weighted bougies, 48 to 54 French, may relieve the dysphagia for several days or weeks, but it is seldom a satisfactory long-term solution.

The definitive treatment of achalasia requires disruption of the circular layer of smooth muscle within the LES area. The two most widely used and analyzed methods of therapy for achalasia are forceful dilatation, either pneumatic or hydrostatic, and esophagomyotomy. Results were considered excellent or good in 65% of patients with dilatation and 85% of those after esophagomyotomy. The perforation (4% versus 1%) and mortality rates (0.5 versus 0.2%) were reported to be higher with dilatation than with esophagomyotomy. However, the advent of volume-limited pressure-controlled balloons (Gruntzig-type) has decreased the perforation rate and mortality of balloon dilatation. A Gruntzig-type balloon is positioned under fluoroscopic control within the LES. The balloon is rapidly inflated to a pressure of 300 torr for 15 seconds. Results from dilatation show that approximately 60% of patients receive complete relief of symptoms after one treatment, and an additional 10% respond to a second treatment. Most patients referred for myotomy have had at least one failed balloon dilatation.

When a perforation does occur after balloon dilation, it can usually be managed by having the patient refrain from eatingfor 1 to 3 days and by administering antibiotics and parenterial nutrition. Other significant complications of pneumatic dilation are infrequent and late gastroesophageal reflux and esophagitis seem to occur in fewer than 1% of patients. Relative contrindications to balloon dilatation for achalasia include an extremely poor medical condition that would preclude repair, if a perforation should occur, extremely young age ( infants and small children ), tortuoust sigmoid esophagus, a previous esophagomyotomy, and the presence of a concomitant sliding hiatal hernia.

A novel pharmacologic treatment of achalasia is intrasphincteric botulinum toxin injected into the LES through the flexible esophagoscope. This potent neurotoxin inhibits the release of acetylcholine from nerve endings and has been used with good results in a number of diseases characterized by muscle spasm (e.g., strabismus and various dystonias). Encouraging early results have been reported, but longer follow-up in patients with achalasia has been disappointing. The efficacy of botulinum toxin has yet to be established.

Surgical treatment, either open or video-assisted, with division of the circular muscle of the lower end of the esophagus, offers precise and less traumatic division of the circular muscle layer of the lower esophagus than that achieved through forceful dilatation with surgery. Results appear superior to those of balloon dilatation, and mortality is low. Major disadvantages include the need for hospitalization, thoracic access, and a low but finite incidence of reflux esophagitis. Excellent early results with laparoscopic esophagomyotomy in the treatment of achalasia have been reported, and this approach is clearly superior to the transthoracic video-assisted esophagomyotomy.

The traditional transthoracic distal esophagomyotomy for achalasia is performed through a left thoracotomy in the sixth or seventh intercostal space. The pleural reflection is incised and the distal esophagus is mobilized, with careful preservation of the vagus nerve. In addition, the esophagogastric junction is mobilized from the esophageal hiatus to allow visualization of 1 to 2 cm of stomach. A linear incision (7 to 10 cm) is made through the longitudinal and circular muscle layer, from the level of the inferior pulmonary vein superiorly down and across the lower sphincter inferiorly, to bring the incision onto the stomach 3 to 5 mm to divide all circular muscle fibers . Separation of the muscularis from the submucosa at the margin of the incision is important to ensure that the divided layers do not reapproximate as healing occurs.

Unresolved technical questions concern the distal extent of the esophagomyotomy and the need for a concomitant antireflux procedure. Some surgeons advocate a short esophagomyotomy carried onto the stomach only far enough to ensure complete division of the distal esophageal musculature, but not far enough to induce incompetence of the LES mechanism. With this approach, several surgeons reported a late incidence of postoperative gastroesophageal reflux of about 8%. Many surgeons believe that complete relief of the obstruction caused by the uncoordinated LES can be achieved only by rendering the LES incompetent, by carrying the esophagomyotomy onto the stomach for 1 to 2 cm. Most esophageal surgeons now carry out a complete esophagocardiomyotomy for achalasia with some type of fundoplication to prevent the subsequent development of gastroesophageal reflux. A 360-degree loose fundoplasty, in which the stomach is wrapped around the lower esophagus, has the potential disadvantage of offering too much resistance to the passage of food. Excellent long-term results suggest that a distal esophagomyotomy combined with a partial fundoplication may be the surgical approach of choice in achalasia. Even with this approach, however, gradual deterioration of esophageal function over time and the late development of gastroesophageal reflux and esophagitis jeopardize the long-term outcome.

Minimally invasive video-assisted techniques to accomplish an esophagomyotomy, both laparoscopically and thoracoscopically, have yielded comparable results to the open approach with less postoperative pain and a shorter hospital stay. Some surgeons prefer a laparoscopic (transabdominal) approach with a partial fundoplication to avoid postoperative reflux. The laparoscopic myotomy has advantages over the thoracoscopic technique. First, anesthesia is easier to administer because a double-lumen tube is not needed. Second, the myotomy can be performed more easily through the abdomen. Last, the absence of a chest tube may decrease postoperative pain. Patti and colleagues reported on 168 patients undergoing minimally invasive esophagomyotomy over an 8-year period. Good or excellent relief of dysphagia was noted in 90% of patients. Even those with a dilated, end-stage esophagus had excellent relief of dysphagia, and none required esophagectomy. They originally performed the myotomy through a thoracoscopic approach but now prefer the laparoscopic approach combined with a partial fundoplication. Based on these excellent results and long-term follow-up (median 28 months), laparoscopic Heller myotomy and partial fundoplication probably should be considered the primary treatment for achalasia. Laparoscopic Heller myotomy is a safe and effective procedure even after unsuccessful treatment with botulinum toxin.

Patients with recurrent esophageal obstruction after esophagomyotomy or a reflux-induced peptic stricture after either esophagomyotomy or forceful dilatation pose a difficult dilemma for the surgeon. Only two thirds of patients undergoing a repeat esophagomyotomy benefit from the operation, and fundoplication for reflux symptoms has even poorer results. A more reliable approach may be esophageal resection and esophageal substitution, preferably with stomach. Esophageal resection provides definitive treatment of the esophageal abnormality, eliminates the late risk of carcinoma, and can be accomplished transhiatally without opening the thorax. This approach is being used with increased frequency in patients with failed prior operations for achalasia or in those with a megaesophagus that may fail to empty adequately even after an esophagomyotomy. Esophagectomy for end-stage achalasia should be strongly considered in symptomatic patients with end-stage disease in whom lesser approaches offer little relief. Eighty-three percent had no or only mild dysphagia, and most had no dietary restrictions.

DIFFUSE ESOPHAGEAL SPASM AND

RELATED HYPERMOTILITY DISORDERS

DES is a poorly understood hypermotility disorder in which patients experience chest pain and/or dysphagia as a result of repetitive, simultaneous, high-amplitude esophageal contractions. The origin of DES is unknown. The patient with DES is typically anxious and complains of chest pain inconsistently related to eating, exertion, and position. The character of the chest pain may mimic that of angina pectoris, often described as squeezing, oppressive, retrosternal pressure that has variable intensity and radiates toward the jaw, down the arms, and frequently straight through to the intrascapular region of the back. Symptoms are often greatest during periods of emotional stress, but the lack of association with exercise and the occasional association of dysphagia with the chest pain suggests an esophageal rather than a cardiac abnormality. Obstructive symptoms are unusual. Many patients experience regurgitation of retained intraesophageal saliva during bouts of DES. Ingestion of cold liquids or foods may aggravate DES, as can gastroesophageal reflux, but most patients with DES do not have reflux. A history of irritable bowel syndrome, pylorospasm, spastic colon, or other functional gastrointestinal complaints is common. Gallstones, peptic ulcer disease, and pancreatitis can all trigger DES.

DIAGNOSIS

The initial evaluation of the patient with DES is the same as that of the patient with chest pain of undetermined origin. A careful history is essential to elucidate causative intra-abdominal disease (e.g., gallstones, gastritis, or peptic ulcer disease). On barium swallow examination, DES is frustratingly variable. Classic curling or a corkscrew esophagus caused by segmental contractions of the circular muscle may be apparent; however, findings range from a distal beaklike taper (suggesting early achalasia) to normal-appearing peristalsis. An esophageal pulsion diverticulum, particularly in a patient with angina-like symptoms, implicates DES. Esophagoscopy should be performed to rule out an infiltrating tumor, esophageal fibrosis, or esophagitis causing radiographic distal esophageal narrowing. Unfortunately, some of the radiographic and manometric criteria of DES are seen in asymptomatic patients. Unless the patient is experiencing spasm at the time of the manometric study, just as with the barium esophagogram, the results may be entirely normal.

|TABLE 37-2 -- Differential Characteristics of Achalasia and Primary Spasm |

| |Achalasia |Vigorous Achalasia |Diffuse Esophageal Spasm |

|Dysphagia |Common |Common |Rare |

|Pain |Rare |Common |Common |

|Barium esophagogram |Abnormal--dilated esophagus, bird-beak |Abnormal |Normal caliber "corkscrew" esophagus |

| |taper | | |

|Endoscopy |Normal |Normal |Normal |

|Motility |Nonrelaxing LES, absent or weak |Nonrelaxing LES + hypertonic |Hypertonic simultaneous, multiphasic |

| |simultaneous contraction after |simultaneous, multiphasic contractions |contractions after swallowing |

| |swallowing |after swallowing | |

|Abbreviation: LES, lower esophageal sphincter. |

The issue is further confounded by the inclusion of a variety of related hypermotility disorders, such as nutcracker esophagus, hypertensive LES, nonspecific esophageal motility disorders, and vigorous achalasia under the generic heading of DES . These conditions, however, are best defined by precise manometric criteria . The classic manometric criteria of DES are simultaneous, multiphasic, repetitive, often high-amplitude contractions that occur after a swallow and spontaneously in the smooth muscle portion of the esophagus. The diagnostic hallmark of DES is the correlation of subjective complaints with objective evidence of spasm on manometric tracings .

Treatment

The treatment of DES is far from satisfactory, because of the general lack of understanding of the etiology of this condition. Documented psychiatric disorders, including depression, psychosomatic complaints, and anxiety, have been reported in more than 80% of patients with esophageal manometric contraction abnormalities. For many patients with DES, simply establishing an esophageal cause of their previously unexplained chest pain and providing reassurance are therapeutic. Patients who complain of dysphagia should avoid stress during meals as well as "trigger" foods or drinks. If gastroesophageal reflux is symptomatic or documented with esophageal function tests, medical treatment of reflux should be initiated. Antispasmodics and calcium channel blockers are occasionally helpful. The response of DES to nitrates is variable, but it may be dramatic. Esophageal dilation with Hurst-Maloney bougies (50 to 60 French) may relieve dysphagia and chest pain from DES for weeks to months and can be repeated on an outpatient basis, as required. The use of pneumatic dilatation to treat DES is not generally advised, because forseful dilatation of a hipertonic spastic esophagus may result in a major tear.

Although thoracic esophagomyotomy has been advocated by some surgeons in the treatment of DES, results are much less favorable than in achalasia, with success in only 50 to 60%. Despite improvement in manometric and radiographic indicators of DES after esophagomyotomy, patients may continue to complain of chest pain and slow emptying. Therefore, only when a patient with LES is incapacitated by chest pain or dysphagia, or in the presence of a pulsion diverticulum of the intrathoracic esophagus, should one perform a long esophagomyotomy in which the muscular coat of the esophagus is split from the esophagogastric junction to above the aortic arch. Controversy exists about whether the LES should be divided in this procedure and whether an antireflux procedure should be included, but obstructive symptoms may not be relieved unless all circular esophageal muscle fibers in this area are transected.

The nutcracker or super-squeeze esophagus is a hypermotility disorder characterized by extremely high-amplitude (up to 225 to 430 mm Hg) progressive peristaltic contractions, often of prolonged duration. Symptoms of chest pain, dysphagia, and odynophagia are like those of DES, and treatment considerations are similar.

Some patients develop clinical and manometric findings with elements of both achalasia and DES and characterized as having vigorous achalasia. Segmental spasm, rather than esophageal dilatation, is often seen on barium swallow examination. Esophageal manometry demonstrates failure of normal LES relaxation ( as in achalasia ), lack progressive peristalsis, and powerful, simultaneous and repetitive esophageal contractions after swallowing.

Esophageal motor disturbances occur in several collagen vascular diseases, such as dermatomyositis, polymyositis, and lupus erythematosus, but particularly scleroderma. Scleroderma or systemic sclerosis, is a disease of unknown etiology that is characterized by induration of the skin, fibrous replacement of the mooth muscle of internal organs, and progressive loss of visceral cutaneous function. Disruption of normal esophageal peristalsis is so common in scleroderma that it is a major diagnostic sign of the disease. As fibrous replacement of the esophageal mooth muscle progressis, the distal esophageal high pressure zone loses its tone and normal response to swallowing, and gastroesophageal reflux occurs. In the distal two thirds of the esophagus normal, progressive peristalsis gives way to weak, simultaneous, nonpropulsive contractions.Patient initially complain of slow emptying of the esophagus, requirring large amounts of water to wash food into the stomach. Heartburn and gastroesophageal reflux are often severe. The prolonged duration of contact between refluxed gastric asid and the esophageal mucosa results in accelerated reflux esophagitis. At esophagoscopy, ulcerative distal esophagitis, with or without significant stricture formation, is common. Use of the combined Collis gastroplasty-fundoplication instead of standard antireflux operations has particular merit in the patient with scleroderma, who typically has severe esophagitis, stricture formation, fibrinoid degeneration, and atrophy of distal esophageal smooth muscle that jeopardize the long-term success of the traditional operations.

Obstructive symptoms due to a competent low sphincter mechanism in a patient with an atonic esophagus, however, may require postoperative dilatation therapy. Advanced esophageal scleroderma, manifested by either severe dilatation or reflux stricture refractory to dilatation and medical therapy, may require esophagectomy with a cervical esophagogastric anastomosis to eliminate reflux esophagitis and to restore the ability to swallow.

Approximate actions base1. Introduction /5 min/. Teacher short characterizes topic actuality, meets students with main aims of the study and plan.

2. Initial knowledge’s control /15 min/.

3. Individual students work with patients /30 min/. The teacher explains some more difficult and important parts of problem. The choice is realized by asking of students and their answers correction.

4. Clinical analyses of topical patients /100 min/. Students observe topical patients under teaches control. After it finishing, the students report about receiving results.

5. Work in dressing-room and operation theater. Teacher and students change the dressings of patients after different surgical procedures on esophagus.

6. Study of X-ray pictures.

7. Final knowledge control. Solution of test-questions /25 min/.

8. Conclusion /5 min/. The teacher concludes the session and gives new task for the next once.

I. Test questions.

1. Choose the disorders of esophageal motility

a) scleroderma/

b) achalasia/

c) DES/

d) reflux-esophagitis

e) vigorous achalasia/

2. Achalasia is characterized with the following symptoms:

a) dysphagia/

b) chest pain

c) regurgitation/

d) dyspnea

e) weight loss/

3. Choose the most accurate diagnostic methods of motor disorders of the esophagus body:

a) X-ray examination/

b) esophagoscopy/

c) esophageal function tests/

d) CT-scanning

4. In case of achalasia forceful dilatation can be

a) Pneumatic/

b) Hydrostatic/

c) dynamic

5. Choose the drugs, which are used in the treatment of achalasia in the early stage:

a) Nitroglycerin/

b) anti-spasmodics

c) long-acting nitratis/

d) calcium-channel blocking agents/

e) antacides

6. What is the late complication of the achalasia? Choose the correct answer:

a) perforation

b) carcinoma developing/

c) profuse bleeding

d) reflux-esophagitis

7. The main symptoms of the upper esophageal sphincter dysfunction are:

a) cervical pain/

b) cervical dysphagia/

c) hoarseness/

d) vomiting

e) heartburn

f) expectoration of excessive saliva/

8. Choose the types of treatment in case of upper esophageal sphincter dysfunction:

a) medical anti-reflux therapy/

b) intermittent bugienage/

c) cervical esophagomyotomy/

d) esophagocardiomyotomy

9. What disease has got the symptoms both of DES and achalasia:

a) scleroderma

b) vigorous achalasia/

c) super-squeze esophagus

10. Mark the main barium swallow examination symptom of DES:

a) dilatation and tortuosity of esophagus

b) corkscrew esophagus/

c) bird-beak taper of the esophagogastric junction

11. Choose the results of scleroderma:

a) bleeding

b) carcinoma development

c) stricture formation/

d) ulcerative esophagitis/

e) esophagus perforation

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