Pathogenesis, clinical manifestations, diagnosis, and treatment progress of achalasia of cardia

Table 2 Ling classification of achalasia cardia

Type	Endoscopic presentation
I	The lumen was slightly dilated and smooth without polyring, crescent-shaped structures, or diverticular structures
II	The lumen was dilated and polycyclic or crescent-shaped structures appeared after inflation
IIa	A thin ring, no crescent structure
IIb	Crescent structure, not more than 1/3 of the lumen
IIc	Crescent structure, more than 1/3 of the lumen
III	The lumen was significantly dilated, with the diverticular structure-like structures
IIIl	Diverticulum structure in the left wall of esophagus
IIIr	Diverticulum structure in the right wall of esophagus
IIIlr	Diverticulum structure in both the left and right walls of esophagus