Peroral endoscopic myotomy in children with achalasia: A review of the literature

Table 1 Achalasia diagnosis, classification and clinical implications

Aspect	Details
Diagnostic methods	1 Barium swallow study: Demonstrates dilated esophagus with tapering distal esophagus ("bird's beak sign")
	2 Esophageal manometry: Gold standard for diagnosis
Achalasia subtypes	Subtype I: Absent distal esophageal pressurization
	Subtype II: Panesophageal pressurization
	Subtype III (A, B, C, D): Spastic contractions (≥ 2) with or without periods of pressurization
	A: Spastic achalasia: Premature/spastic contractions with impaired LES relaxation
	B: Hypercontractile achalasia: High amplitude and long-duration contractions with incomplete LES relaxation
	C: Segmental achalasia: Abnormal contractions limited to specific segments (commonly distal third)
	D: Peristaltic achalasia: Proximal esophageal peristalsis retained with distal esophagus spastic activity
Clinical presentation	Subtype I: 100% failure of peristalsis
	Subtype II: Increased IRP, commonly associated with weight loss
	Subtype III: Chest pain common symptom
Clinical implications	Patients with subtype II are more likely to respond to operative interventions

LES: Lower esophageal sphincter; IRP: Integrated relaxation pressure.