Miscellaneous Abnormalities of the Esophagus

Instrumentation

Endoscopic procedures account for nearly 75% of esophageal perforations. ^, Most endoscopic perforations in the hypopharynx involve the piriform sinuses or cricopharyngeal region. ^, The risk of perforation is greater in patients with cervical osteophytes or pharyngeal diverticula. In contrast, thoracic perforations usually result from endoscopic injury at or just above esophageal strictures or from therapeutic interventions, including esophageal surgery, tube or stent placement, and endoscopic balloon dilation, bougienage, or sclerotherapy. ^{, ,}

Foreign Bodies

In adults, most foreign body perforations in the hypopharynx are caused by animal or fish bones lodged in the piriform sinus or cricopharyngeal region. In contrast, foreign body perforations in the thoracic esophagus are usually caused by food impactions with transmural inflammation and pressure necrosis at the site of impaction (see later, “Foreign Body Impaction”).

Trauma

Penetrating injuries to the esophagus are usually caused by knife or bullet wounds. Rarely, blunt trauma to the neck, chest, or abdomen can also lead to pharyngeal or esophageal perforation.

Spontaneous Esophageal Perforation (Boerhaave’s Syndrome)

In spontaneous esophageal perforation, also known as Boerhaave’s syndrome, a sudden, rapid increase in intraluminal esophageal pressure causes a full-thickness perforation of the thoracic esophagus with ensuing mediastinitis, sepsis, and shock. Most cases result from violent retching or vomiting, usually after an alcoholic binge. ^, Other causes include coughing, weightlifting, childbirth, defecation, seizures, and asthma attacks.

Spontaneous esophageal perforation is usually characterized by a 1- to 4-cm long, linear tear on the left lateral wall of the distal esophagus near the gastroesophageal junction. ^, The left side of the distal esophagus is more vulnerable to perforation because the right side is protected by the descending thoracic aorta. Rarely, spontaneous perforation of the upper thoracic or cervical esophagus has been reported.

Cervical Esophageal Perforation

Patients with pharyngeal or cervical esophageal perforation typically present with neck pain, dysphagia, fever, and/or crepitus in the neck. Untreated perforations may be complicated by the development of a neck abscess, rarely leading to sepsis and shock.

Most cervical esophageal perforations heal on conservative management with antibiotics and no food or fluid by mouth. However, larger perforations may require a cervical mediastinotomy and open drainage to prevent abscess formation. Cervical esophageal perforations have a much better prognosis than thoracic esophageal perforations, with an overall mortality rate of less than 15%.

Thoracic Esophageal Perforation

Patients with thoracic esophageal perforation may present with a classic triad of vomiting, substernal chest pain, and subcutaneous emphysema in the chest wall and neck. However, some patients have pain referred to the left shoulder or back, and others have epigastric pain if the perforation involves the intra-abdominal esophagus. Furthermore, subcutaneous emphysema is not always present on physical examination. As a result, thoracic esophageal perforation can be mistaken for other acute thoracic or abdominal conditions. Unfortunately, the mortality rate for untreated thoracic esophageal perforation approaches 70% by 24 hours. Early diagnosis and treatment are therefore essential for this life-threatening condition.

Thoracic esophageal perforations often require an emergent thoracotomy with surgical closure of the perforation and mediastinal drainage to prevent the development of mediastinitis, sepsis, and death. In recent years, placement of covered esophageal stents has become an increasingly common alternative to surgery with excellent results. Other small, contained perforations can be managed conservatively with broad-spectrum antibiotics.

Plain Radiographs

Cervical Esophageal Perforation

Subcutaneous emphysema or retropharyngeal gas may be visible on anteroposterior or lateral neck radiographs within 1 hour after pharyngeal or cervical esophageal perforation ( Fig. 14.4A ). Extraluminal gas can dissect along fascial planes from the neck into the chest, producing pneumomediastinum (see Fig. 14.4A ). Lateral neck radiographs may also show widening of the prevertebral space, anterior tracheal deviation, and, eventually, a retropharyngeal abscess containing mottled gas or a single air-fluid level.

Thoracic Esophageal Perforation

About 90% of patients with thoracic esophageal perforation have abnormal chest radiographs. The earliest signs include mediastinal widening and pneumomediastinum, manifested by radiolucent streaks of gas along the lateral borders of the aortic arch and heart ( Fig. 14.5A ). ^{, ,} Mediastinal gas may then dissect along fascial planes superiorly into the supraclavicular region or neck.

Approximately 75% of patients with thoracic esophageal perforation have a pleural effusion or hydropneumothorax. Distal perforations often result in a sympathetic left pleural effusion or left basilar atelectasis (see Fig. 14.5A ). If the mediastinal pleura ruptures, gas and fluid can enter the pleural space, producing a hydropneumothorax. Because the distal esophagus directly abuts the mediastinal pleura on the left, 75% of hydropneumothoraces are on the left (5% are on the right and 20% are bilateral).

Abdominal radiographs may reveal extraluminal gas in the retroperitoneum or lesser sac when the perforation involves the intra-abdominal esophagus. ^, Symptoms may be confined to the abdomen, further delaying the diagnosis. Fortunately, intra-abdominal esophageal perforations have a more benign clinical course, sometimes healing on conservative treatment. ^,

Fluoroscopic Examinations

Fluoroscopic esophagography is an excellent study for evaluating patients with suspected esophageal perforation. The ideal contrast agent provides diagnostic information about the site and extent of perforation without posing a risk to the patient. In experimental studies, it has been shown that barium in the mediastinum can incite an inflammatory reaction with subsequent granuloma formation and fibrosis, but there is no evidence that mediastinal barium causes clinically significant mediastinitis. Nevertheless, extravasated barium can remain in the mediastinum indefinitely, compromising the radiologist’s ability to assess healing of leaks on follow-up studies.

Water-soluble contrast agents such as diatrizoate meglumine and diatrizoate sodium (Gastroview, Mallinckrodt, St. Louis, MO) have no known deleterious effects on the mediastinum and, unlike barium, water-soluble contrast agents are absorbed rapidly, so follow-up studies to assess healing of leaks are not compromised by residual contrast material in the mediastinum. Many authors therefore favor using a water-soluble contrast agent as the initial medium for evaluating patients with suspected esophageal perforation. However, hypertonic water-soluble contrast agents may cause severe pulmonary edema if aspirated into the lungs. Some authors therefore favor using low-osmolality water-soluble contrast agents such as iohexol (Omnipaque, GE Healthcare, Princeton, NJ) to decrease the risks associated with aspiration of ionic contrast material. When water-soluble contrast agents are used, the pharynx should be carefully observed at fluoroscopy, and the study should be aborted if aspiration is detected.

A major disadvantage of water-soluble contrast agents is that they are less radiopaque than barium, limiting detection of perforations, particularly ones that are small or subtle. As a result, 50% of cervical esophageal perforations and 25% of thoracic esophageal perforations are missed on fluoroscopic examinations performed only with water-soluble contrast agents. Because of its greater opacity and better adherence to sites of perforation, high-density barium can detect 50% of leaks not visualized with water-soluble contrast agents. When the initial study with a water-soluble contrast agent fails to show a leak ( Fig. 14.6A ), the examination therefore should immediately be repeated with high-density barium to detect subtle leaks that otherwise would go unrecognized ( Fig. 14.6B ). ^{, , , ,} If a leak is present, the downside of retained barium in the mediastinum is more than offset by the earlier diagnosis and treatment of a potentially life-threatening condition.

Esophageal perforations are recognized on esophagography by extravasation of contrast agent from the esophagus into the neck or mediastinum. In patients with spontaneous esophageal perforation, the contrast agent is usually seen to extravasate from the left lateral wall of the distal esophagus into the adjacent mediastinum (see Fig. 14.5B ). Rarely, spontaneous perforation of the upper thoracic or cervical esophagus may occur. Regardless of the site of perforation, a sealed-off leak is typically characterized by a blind-ending track or contained extraluminal collection (see Fig. 14.6B ). In contrast, larger perforations result in free extravasation of contrast agent into the mediastinum (see Figs. 14.4B and 14.5B ). In patients with contained perforations that are treated conservatively, follow-up esophagrams are often obtained to confirm healing prior to initiating oral feeding.