Table 2.

Variations in the left upper pulmonary vein.

	Type	Subtype	Patients
Variations in the left upper pulmonary vein	The confluence and distribution of V(1 + 2)b + c	Descending central venous type: V(1 + 2)b + c trunk walked below B3	18
		No central venous type: V(1 + 2)b and V(1 + 2)c walked above and below B3, respectively	10
		Ascending central venous type: V(1 + 2)b+c trunk walked above B3	75
	The development of V(1 + 2)c*	Development of V(1 + 2)c* was relatively less	70
		Development of V(1 + 2)c* was relatively stout	33

V, Vein.