MKSAP Quiz: progressive dysphagia
Dabigatran may be cost-effective for stroke prophylaxis in atrial fibrillation
A 74-year-old woman is evaluated for 3 years of progressive dysphagia, first for solid foods and now for both solid foods and liquids; she has had frequent episodes of regurgitation of undigested food and has lost 6.8 kg (15 lb) during the past 6 months. Her medical history includes stenting of the left anterior descending coronary artery 1 year ago after which she has had symptomatic residual distal stenosis. She had a cerebrovascular accident 2 years ago and still has mild residual right hemiparesis. Her medications include metoprolol, clopidogrel, enalapril, aspirin, and hydrochlorothiazide
On physical examination, the patient is thin (BMI 20) and appears ill, although not in distress. Vital signs are normal. Chest radiograph shows a dilated esophagus with an air/fluid level and changes of chronic aspiration in the right lung base. Barium esophagography shows “bird beak” narrowing of the distal esophagus and mega-esophagus with retained fluid in the esophageal body. Esophageal manometry shows aperistalsis of the esophageal body and incomplete lower esophageal sphincter relaxation with swallowing. On esophagogastroduodenoscopy, the endoscope passes through the lower esophageal sphincter without resistance; there are no masses in the esophagus or the gastric cardia.
Which of the following additional interventions is most likely to improve survival for this patient?
A. Anticholinergic therapy
B. Botulinum toxin injection
C. Laparoscopic myotomy
D. Pneumatic dilatation
MKSAP Answer and Critique
The correct answer is B) Botulinum toxin injection. This item is available to MKSAP 15 subscribers as item 26 in the Gastroenterology and Hepatology module.
This patient's history is typical for achalasia, an uncommon but important primary motility disorder of the esophagus. Although endoscopic evaluation is required to investigate the possibility of a mass lesion leading to partial esophageal obstruction, the diagnosis of achalasia is made manometrically using esophageal motility studies. The manometric diagnosis usually includes an elevated lower esophageal sphincter resting pressure, failure of the lower esophageal sphincter to relax with swallowing, and diminished or absent peristalsis of the esophageal body. Radiologic findings of note in achalasia include a “bird's beak” abnormality of the distal esophagus, widening of the esophagus, and, less commonly, megaesophagus with an air/fluid level. CT of the chest can be employed to differentiate achalasia from pseudoachalasia, the latter mimicking the true motility disorder but caused by a mass lesion at the distal esophagus or gastric cardia.
Treatment of achalasia is usually pneumatic dilatation of the esophagus or surgical myomectomy, the latter of which can be done laparoscopically. Pneumatic dilatation, even in experienced hands, is associated with a 5% to 10% risk of esophageal perforation. Botulinum toxin injection can afford relief of achalasia in patients like this one who because of age or comorbidities are not candidates for endoscopic or surgical intervention. Botulinum toxin inhibits the release of acetylcholine from nerve endings and has been used successfully for decades to treat certain spastic disorders of skeletal muscle such as blepharospasm and torticollis. Anticholinergic therapy is not indicated for achalasia.
Key Point
- Botulinum toxin injection can afford relief of achalasia in patients who because of age or comorbidities are not candidates for endoscopic or surgical intervention.