Achalasia

Description

• Primary esophageal dysmotility
• Absence of esophageal peristalsis and impaired relaxation of the lower esophageal sphincter (LES)

Epidemiology

• 1 to 2/100,000 population/year (1)
• Age of peak incidence: 30 to 60 years

• 10/100,000 population (2)
• Male = female
• No racial or ethnic preference

Etiology and Pathophysiology

• Impaired inhibitory innervation of esophageal smooth muscle and the LES (3)
  • Inflammatory process leading to the degeneration of ganglion cells in the myenteric plexus, resulting in the loss of inhibitory neurotransmitters: nitric oxide (NO) and vasoactive intestinal polypeptide (VIP)
• Etiologies (3)
  • Primarily idiopathic
  • May have an autoimmune, viral, or neurodegenerative component
  • May be associated with certain genetic syndromes (Down and Allgrove syndrome) (3)

Risk Factors

No identifiable risk factors

General Prevention

No identifiable preventive measures

History

• Dysphagia to solids and liquids, gradually worsening over time (1,2)
• Regurgitation (most commonly at night in the recumbent position) (1,2)
  • Can result in nocturnal cough and aspiration
• Nonsevere, reflux-type chest discomfort or pain
• Indolent course
• Sitophobia (fear of eating) can lead to weight loss.

Physical Exam

No specific physical exam findings

Differential Diagnosis

• Secondary achalasia (pseudoachalasia) (1,3)
  • Attributed to a specific cause (e.g., GERD, hiatal hernia, psychosomatic manifestations)
  • Accounts for 4% of cases with manometric findings consistent with achalasia
  • Malignancy is the most common cause of pseudoachalasia.
  • Adenocarcinoma of the gastric cardia accounts for 75% of secondary achalasia.
  • Consider if short duration (<1 year) of symptoms, significant weight loss and age >55 years.
• Chagas disease (Trypanosoma cruzi)
• Scleroderma
• Intestinal pseudo-obstruction
• Postsurgical changes/dysmotility
  • Postvagotomy, fundoplication, laparoscopic gastric band

Diagnostic Tests & Interpretation

• Barium esophagram/fluoroscopy (1,2,3)[C]
  • Classic “bird’s beak” tapering of the distal esophagus and dilation of the esophageal body; may also see corkscrew appearance with aperistalsis
  • Tertiary contractions seen in early stages
  • Poor emptying of barium
  • Column height of retained barium at 1 and 5 minutes after ingestion helps gauge severity.
• Chest CT scan (1,2,3)[C]
  • May show dilated esophagus (mega- or “sigmoid” esophagus, if severely dilated)

• Esophageal manometry (gold standard) (1,3)[C]
  • Confirms diagnosis or for preoperative assessment
  • Will show aperistalsis of the esophageal body and impaired relaxation of the LES during a swallow
• High-resolution esophageal manometry (HREM) (1,2,4)[C]
  • More sensitive than standard manometry (97%)
  • Objectively measures elevated LES pressure (>15 mm Hg integrated relaxation pressure [IRP] is the cutoff.)
  • Allows for subclassification into three types (Chicago classification) based on pattern of contractility within esophagus
    • Type I (classic): no pressure waves recorded in distal esophagus
    • Type II (pan-pressurization): panesophageal pressurizations
    • Type III (spastic): >20% of swallows have rapidly propagating or spastic concomitant contractions.
• Esophagogastroduodenoscopy (EGD) (1,2,3)[C]
  • Retained food/liquid and dilated esophagus suggest achalasia.
  • Helps exclude pseudoachalasia
  • A normal EGD does not rule out a clinical diagnosis of achalasia as 40% of patients have normal endoscopy.
  • American Gastroenterology Association (AGA) guidelines: Perform EGD on all patients diagnosed with achalasia to evaluate for esophagitis and exclude pseudoachalasia (2)[C].
• Functional lumen imaging probe (FLIP) (1)[C]
  • Relatively new diagnostic modality which measures the cross-sectional area and impedance patterns at the EG junction
  • Efficacy and applicability to routine clinical practice still to be determined

General Measures

• Primary goal of management is to prevent complications and preserve esophageal structure and function.
• Oral/sublingual medications provide short-term treatment and are not as effective as endoscopic and surgical therapies which are more definitive.
• Type II achalasia typically responds best to treatments, whereas type III has worst response (4).

Medication

Drug therapy

• Nitrates and calcium channel blockers
  • Reduce LES pressure and relax smooth muscle (1,2)[C]

Surgery/Other Procedures

Endoscopic

• Endoscopic botulinum toxin injection (EBTI) (1,3)[C]
  • Inhibits acetylcholine release and diminishes its stimulation, thus lowering LES pressure
  • First treatment lasts about 6 months.
  • 40% patients need repeated treatments which last for a shorter duration.
  • May be the best option for patients who are not candidates for definitive therapy (dilation or myotomy)
• Endoscopic pneumatic balloon dilation (PD) (1,3)[C]
  • Was the primary nonsurgical therapy prior to botulinum toxin injections
  • Typically requires endoscopic and/or fluoroscopic guidance
  • Low risk of perforation with graded serial dilations
  • Not as definitive as surgery (2- to 5-year duration)
• Laparoscopic Heller myotomy (LHM) (1,2)[C]
  • Most reliable and durable treatment option
    • First myotomy completed in 1913
    • Durability of 5 to 7 years
  • Myotomy extends 2 to 3 cm to the proximal stomach to further reduce LES pressures (to <10 mm Hg) and to reduce dysphagia.
  • Associated with increased postoperative gastroesophageal reflux
    • Concurrent fundoplication often done to reduce postoperative reflux
• Peroral endoscopic myotomy (POEM) (1,2,3)[C]
  • Relatively new therapy (first completed in 2008) which provides adequate symptom relief and is less invasive than LHM
  • Submucosal tunnel created with an endoscopic electrocautery knife; myotomy performed within this tunnel which is closed using endoscopic clips
  • May be preferred approach in type III achalasia were the myotomy can be tailored to include distal esophageal spasm
  • Rate of postprocedure reflux not significantly different from LHM
  • RCTs comparing POEM to other modalities needed
• Self-expanding metal stent (SEMS) (5)[C]
  • Temporary placement of a self-expanding covered metal stent across the GE junction
  • Efficacy may be similar to LHM but more studies needed.
• Endoscopic sclerotherapy (5)[C]
  • Endoscopic injection of a sclerosing agent (i.e., ethanolamine) to the LES creating localized muscle necrosis
  • Small number of observational studies with promising results; injections every 2 weeks until resolution of dysphagia
• Esophagectomy (5)[C]
  • Last-resort treatment option
  • High morbidity and mortality

Issues For Referral

LHM and POEM efficacy is operator-dependent. Referral should be made to high-volume centers to optimize outcomes and minimize adverse events and complications.

Complementary and Alternative Medicine

No routine alternative or complementary therapies for achalasia

Inpatient Considerations

Post-LHM and post-POEM inpatient care vary by facility, with institutions having protocols for routine postprocedure care.

Follow-up Recommendations

• Obtain a posttreatment barium study to evaluate for resolution.
• Consider proton pump inhibitor in patients with reflux symptoms.
• Reassess for treatment failure or recurrence of diseases based on symptoms.

Diet

• Pretreatment diet is limited to what is tolerated.
• No diet limitations in effectively treated patients after the immediate postoperative period

Prognosis

Based on longitudinal studies, there is no impact on life expectancy.

Complications

• Chronic esophageal dilation and stasis may result in local inflammation that increases risk for esophageal cancer (3)[C].
• American Society for Gastrointestinal Endoscopy (ASGE) favors radiographic or endoscopic surveillance for cancer every 3 years if achalasia has been present for >10 to 15 years (3)[C].

ICD-10

• K22.0 Achalasia of cardia

ICD-9

• 530.0 Achalasia and cardiospasm

SNOMED

• 266434009 Esophageal dysmotility
• 45564002 Achalasia of esophagus
• 48531003 Achalasia
• 715192004 Idiopathic achalasia of esophagus