Open Pulmonary Valvotomy : Open pulmonary valvotomy by technique of inflow occlusion is done without cardio pulmonary bypass. Surface hypothermia is used and inflow occlusion (SVC and IVC) and vertical pulmonary arteriotomy is done. Fused pulmonary valve commissures are divided upto their attachment at pulmonary annulus.
The incision is done with a knife as much as possible as one is not worried even if it produces mild regurgitation. These days valvotomy is done on CP bypass.