Medscape J Med. 2008; 10(10): 248.
A 12-Year-Old Boy With Progressive Dysphagia
Case Presentation
A 12-year-old boy presented with a chief complaint of progressive difficulty swallowing over the previous 18 months. Initially, he only experienced dysphagia when eating solid food, but more recently had difficulty swallowing liquids as well. He reported that for the last 3 months he has been “unable to keep anything down” and had lost 10 lbs. He did not complain of odynophagia. He and his parents reported that he had a normal appetite and no feeding aversion. He complained of heartburn and occasional regurgitation, as well as nighttime cough. There were no other symptoms present.
The patient's medical history was significant for having been diagnosed with neuroblastoma 7 years ago. His treatment included surgery, radiation therapy targeting the lower lumbar region, and chemotherapy. He experienced a relapse in the previous year and underwent stem cell transplant 4 months earlier that was complicated by severe mucositis. He has had no other significant medical history and his family medical history is noncontributory. His current medications include lansoprazole and metoclopramide (which have not helped his symptoms), trimethoprim-sulfa, and zolpidem. The remainder of his review of systems was negative.
On physical examination, the patient's weight was 27.4 kg (less than 5th percentile) and his height was 143.8 cm (10th-25th percentile). Vital signs were normal. In general he was thin but otherwise well appearing. Examination of his head, eyes, ears, nose, and throat was normal, including no evidence of active mucositis. His lung and heart examinations were unremarkable. His abdomen was soft, nontender, and nondistended with normal bowel sounds and no hepatosplenomegaly or masses appreciated. His skin revealed no rashes. The remainder of his physical examination was unremarkable.
Diagnostic Questions
1. What is the differential diagnosis?
Dysphagia is most commonly due to functional causes or anatomic abnormalities affecting the esophagus. An esophageal stricture, web, or mass as well as an extra-esophageal vascular ring are all possible anatomic causes of dysphagia. Radiation therapy can result in stricturing of the gastrointestinal tract. A functional disorder of esophageal peristalsis such as achalasia has to be considered as well. Esophageal mucosal inflammation due to gastroesophageal reflux disease (GERD); infections, such as Candida esophagitis; or food allergy manifested as eosinophilic esophagitis could also result in progressive dysphagia. Neuromuscular disorders that affect coordination of swallowing, such as myasthenia gravis or familial dysautonomia, can also present with dysphagia, but are unlikely in the absence of other significant findings. Finally, paraneoplastic syndrome should be considered in this setting.
2. What would be your initial diagnostic test?
The best initial diagnostic test would be a barium swallow. This will allow for visualization of the esophagus via contrast radiography to determine if there is any evidence of a narrowing due to a stricture, an intraluminal mass, or extraluminal compression. Additionally, abnormal peristalsis or an unusually dilated esophagus might represent evidence of a motility disorder.
Additional Diagnostic Work-Up
The patient underwent a barium swallow (Figure 1).
Diagnostic Questions
3. How would you interpret the findings from the barium swallow?
The esophagus appears patulous and dilated with irregular contractions and retained secretions. It tapers abruptly to a beak at the gastroesophageal junction, with only minimal contrast material emptying into the stomach.
4. On the basis of the findings on barium swallow, what is the most likely diagnosis and what additional test would you recommend to confirm it?
The findings on barium swallow are consistent with those expected from achalasia. Esophageal manometry should be performed to confirm this diagnosis.
Confirming the Diagnosis
The patient underwent esophageal manometry to confirm the diagnosis of achalasia (Figure 2).
The classic manometry findings associated with achalasia include: (1) incomplete relaxation of the lower esophageal sphincter (LES) in response to swallowing, (2) high resting LES pressure, and (3) absent esophageal peristalsis. The lowest graph on the tracing from the patient's manometry shown above, represents the LES and the gray boxes represent swallowing. The LES does not completely relax, and the average resting pressure of 45 mm Hg is elevated. Absent esophageal peristalsis is not well represented in this image.
Discussion
Esophageal achalasia is a motor disorder of the esophagus that presents with functional obstruction at the gastroesophageal junction. It is characterized by a lack of esophageal peristalsis, increased LES pressure, and partial or incomplete LES relaxation. Achalasia is relatively uncommon; the incidence is approximately 1 case per 100,000 people, with less than 5% manifesting symptoms prior to 15 years of age.
The pathophysiology of achalasia is not entirely clear. Most cases are idiopathic and sporadic. The incomplete relaxation of the LES seems to be due to the fact that postganglionic inhibitory nerves are either absent, reduced, or impaired. Ganglion cell degeneration occurs over time, and the progressive nature of the disease mirrors the progression of these lesions. Autoimmune, infectious, and environmental causes have been implicated as mediators of this process. More recent studies have demonstrated the reduction or absence of nitric oxide and vasoactive intestinal polypeptide, which are thought to contribute to relaxation of the LES, in patients with achalasia.
The typical age at presentation is during the third or fourth decades of life. The mean age of pediatric presentation, based on a compilation of pediatric series, is 8.8 years, with the youngest reported case occurring in a 900-g, 14-day-old premature infant. The mean duration of symptoms prior to diagnosis is 23 months.
The most common presenting symptoms in children tend to be emesis (80%), dysphagia (75%), weight loss (64%), respiratory symptoms, odynophagia, chest pain, failure to thrive, and nocturnal regurgitation. In younger children, respiratory symptoms are more common, including choking, cough, and recent chest infections, as well as feeding aversion. Adolescents are more likely to present with similar symptoms as adults, including dysphagia, vomiting, and weight loss. Dysphagia initially is limited to solid food but often will progress to include difficulty swallowing liquids. The patient will often complain of food becoming stuck in the chest and requiring multiple forceful swallows for eventual passage. Additionally, emesis of undigested food ingested hours or even days earlier might occur.
The differential diagnosis includes an esophageal stricture, which commonly will only result in dysphagia for solid food. Dysphagia can be the presenting symptom of eosinophilic esophagitis, a disease of children and adults characterized by a severe eosinophilic infiltrate of the esophagus that does not respond to acid blockade but does improve with the removal of dietary antigens. Inflammatory esophagitis from GERD or infectious esophagitis, particularly from Candida, could present similarly. Esophageal masses, such as leiomyomas, have been reported to mimic achalasia in pediatric cases. Chagas disease has to be considered in endemic areas, particularly South America. Last, patients thought to suffer from anorexia nervosa who complain of dysphagia for solids and liquids should be carefully evaluated for achalasia.
The initial diagnostic test is typically radiography. A chest radiograph might demonstrate evidence of a widened mediastinum and an air fluid level with an absent gastric air bubble. A barium swallow will often demonstrate a dilated esophagus with the tapering at the gastroesophageal junction, known as the typical “bird's beak” appearance (Figure 1). While the barium swallow is highly sensitive and specific for achalasia, the degree of abnormality does not correlate well with clinical severity. Esophageal manometry is the study of choice to confirm the diagnosis of achalasia. The classic findings include absence of esophageal peristalsis, increased LES pressure, and incomplete and abnormal LES relaxation. Endoscopy can be used to rule out the presence of an inflammatory, infectious, or mass lesion.
Therapy for achalasia has evolved since the initial treatment described more than 300 years ago, which consisted of passage of a carved whale bone with an affixed sponge through the esophagus. Pharmacologic therapy for achalasia has not proven to be very efficacious. Isosorbide dinitrate, a smooth muscle relaxant, and calcium-channel blockers have been implemented given that they reduce LES pressure, but their effect is transient and there are considerable side effects, thus they are rarely used for pediatric achalasia. Endoscopic injection of botulinum toxin into the LES can provide symptomatic relief for a majority of patients, but sustained response is not common and more definitive treatment, such as pneumatic dilatation or surgery, is usually still required. Additionally, there is some concern that prior injection might render future surgical therapy more difficult, although this is controversial.
Pneumatic dilatation of the esophagus intends to forcefully stretch and carefully tear the LES, resulting in relief of the distal esophageal obstruction and clinical improvement. Results of pneumatic dilatation in pediatric patients are variable, with different series reporting improvement in 35% to 100% of patients. Many patients who do improve will require a repeat procedure for recurrence of symptoms. The risk for perforation has been reported to range from 1% to 12%, and the long-term risk for gastroesophageal reflux ranges from 5% to 12%.
The most commonly used surgical procedure for achalasia is a Heller myotomy, in which a vertical incision is made along the serosal surface of the distal esophagus and extends across the muscle fibers of the LES. The goal is to relieve the obstruction without increasing the incidence of reflux. Excellent results are reported in approximately 75% of pediatric patients undergoing this procedure. With minimally invasive techniques, the complication rate and length of recovery have decreased. Accordingly, some centers are beginning to consider Heller myotomy the first-line treatment of choice as opposed to the traditional approach of performing surgery on patients who failed to respond to, or suffered complications from, pneumatic dilatation. The most common complication is gastroesophageal reflux, prompting some centers to recommend that all patients who undergo myotomy also have a concomitant fundoplication performed.
After being diagnosed with achalasia, the patient underwent pneumatic dilatation. This resulted in immediate improvement in his symptoms, and at 1 year follow-up he was not experiencing any dysphagia and was tolerating an unlimited diet.
Footnotes
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