Randomization
The researchers, not the operators, put one of the two surgical schemes into an opaque envelope which has the same appearance and size and 100 envelopes are allocated for each scheme. After these envelopes are completely messed up, write a code on the outside of the envelope, seal it and give it to the operator. When a research object enters the study, if it meets the inclusion criteria and exclusion criteria, number the patient, open the corresponding numbered envelope, and perform the surgery according to the grouping scheme in the envelope. The treatment plan received by each subject was determined by the generated random sequence.