Alocated to MSG group(n=xx)
MSG group(n=58)
Enrollment
Follow-up
Aanlysis
SSG group(n=56)
Excluded patients(n=xxx）due to thoracotomy and other reasons need multiple tubes or different type tube （n=xxx）
Alocated to SSG group(n=xx)
Allocation
Evaluation eligibility(n=114)
randomized(participants n=114 )
Randome
